148 results on '"Hyung Jung Kim"'
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2. Positive Effects of the National Cigarette Price Increase Policy on Smoking Cessation in South Korea
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Do Sun Kwon, M.D., Tae Hee Kim, M.D., Min Kwang Byun, M.D., Ph.D., Hyung Jung Kim, M.D., Ph.D., and Korean Smoking Cessation Study Group
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cigarette price ,south korea ,smoking ,policy ,Diseases of the respiratory system ,RC705-779 - Abstract
Background In January 2015, South Korea's government raised the cigarette tax, and the retail price of cigarettes abruptly increased by 80% compared to the previous year. This research aimed to determine the effect of this increase on smoking cessation among South Korean smokers. Methods We analyzed data collected by the 2013–2015 South Korea National Health and Nutrition Examination Survey of 15,203 South Koreans over 19 years old using regression analysis. We examined the recent non-smoking period of nonsmoking people, prepared according to the survey, and analyzed the recent smoking cessation ratio. Results Among smokers, from 2013 to 2014, the smoking cessation rate was 7.2%, and it increased to 9.9% in 2015 after the increase in the cigarette tax. In 2015, the recent smoking cessation rate was higher among people over the age of 60 (odds ratio [OR], 2.67) compared to those between the ages of 40 and 49. The recent smoking cessation rate was higher among people with below elementary education (OR, 2.28) and above university education (OR, 1.94) compared to high school, higher for those with apartments (OR, 1.74) compared to general type residences, and higher among those with a household income in the low-middle quartile (Q2) (OR, 2.32) compared to the highest quartile (Q4). Conclusion This innovative policy including increase in cigarette prices affected smoking cessation, and its impact varied by sub-group of smokers in South Korea.
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- 2020
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3. Variable effects of underlying diseases on the prognosis of patients with COVID-19.
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Yong Jun Choi, Ju-Young Park, Hye Sun Lee, Jin Suh, Jeung Yoon Song, Min-Kwang Byun, Jae Hwa Cho, Hyung Jung Kim, and Hye Jung Park
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Medicine ,Science - Abstract
Underlying diseases might be risk factors for poor prognosis in patients with coronavirus disease (COVID-19); however, we still do not know whether these diseases are independent factors affecting prognosis, which type of underlying diseases are risk factors, and which type of clinical outcomes are affected. We retrospectively reviewed cohort data from 7,590 de-identified patients with COVID-19 who were diagnosed using severe acute respiratory syndrome-coronavirus-2 RNA polymerase chain reaction test up to May 15, 2020. We used linked-medical claims data provided by the Health Insurance Review and Assessment Service in South Korea. Underlying diseases were identified using the diagnostic codes in the patients' files from January 1, 2019 to December 31, 2019. The total mortality rate was 3.0% in patients with COVID-19. After adjusting for age, sex, and concomitant chronic conditions, we found that congestive heart failure, chronic pulmonary diseases, diabetes without chronic complications, renal diseases, and malignancy were factors that significantly increased the cost of treatment. Cerebrovascular disease, chronic pulmonary disease, and paralysis were found to be independent factors significant in prolonging hospital stay. Diabetes with chronic complications was independently associated with intensive care unit admission. In addition, underlying congestive heart failure (odds ratio [OR], 1.724; P = 0.003), dementia (OR, 1.598; P = 0.012), diabetes with and without chronic complications (OR, 1.821; P = 0.002 and OR, 1.518; P = 0.022, respectively), renal disease (OR, 2.299; P = 0.002), and malignancy (OR, 1.529; P = 0.039) were significant factors associated with death, even after adjustments. Underlying diseases were significant independent factors of the poor prognosis in patients with COVID-19. The effects were variable according to the type of underlying disease and clinical outcome. Therefore, patients with COVID-19 with underlying diseases should be monitored more closely because they are more at risk of a poor prognosis.
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- 2021
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4. Significant predictors of medically diagnosed chronic obstructive pulmonary disease in patients with preserved ratio impaired spirometry: a 3-year cohort study
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Hye Jung Park, Min Kwang Byun, Chin Kook Rhee, Kyungjoo Kim, Hyung Jung Kim, and Kwang-Ha Yoo
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Chronic obstructive pulmonary disorder ,Prognosis ,Spirometry ,Diseases of the respiratory system ,RC705-779 - Abstract
Abstract Background Preserved ratio impaired spirometry (PRISm) is an incompletely understood respiratory condition. We investigated the incidence and significant predictive factors of chronic obstructive pulmonary disease (COPD) in PRISm patients. Methods From 11,922 subjects registered in the Korea National Health and Nutrition Examination Survey, never or light smokers, young subjects, and those already medically diagnosed with COPD (defined by ICD-10 code and prescribed medication) were excluded. The 2666 remaining subjects were categorized into PRISm (normal forced expiratory volume in the first second [FEV1]/force vital capacity [FVC] [≥ 0.7] and low FEV1 (
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- 2018
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5. Regular follow-up visits reduce the risk for asthma exacerbation requiring admission in Korean adults with asthma
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Hye Jung Park, Min Kwang Byun, Hyung Jung Kim, Chul Min Ahn, Chin Kook Rhee, Kyungjoo Kim, Bo Yeon Kim, Hye Won Bae, and Kwang-Ha Yoo
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Asthma ,Compliance ,Exacerbation ,Immunologic diseases. Allergy ,RC581-607 - Abstract
Abstract Background Asthma requires regular follow-up visits and sustained medication use. Although several studies have reported the importance of adherence to medication and compliance with the treatment, none to date have reported the importance of regular follow-up visits. We investigated the effects of regular clinical visits on asthma exacerbation. Methods We used claims data in the national medical insurance review system provided by the Health Insurance Review and Assessment Service of Korea. We included subjects aged ≥ 15 years with a diagnosis of asthma, and who were prescribed asthma-related medication, from July 2013 to June 2014. Regular visitors (frequent visitors) were defined as subjects who visited the hospital for follow-up of asthma three or more times per year. Results Among 729,343 subjects, 496,560 (68.1%) were classified as regular visitors. Old age, male sex, lack of medical aid insurance, attendance of a tertiary hospital, a high Charlson comorbidity index, and a history of admission for exacerbated asthma in the previous year were significant determining factors for regular visitor status. When we adjusted for all these factors, frequent visitors showed a lower risk of asthma exacerbation requiring general ward admission (odds ratio [OR] 0.48; 95% confidence interval [CI] 0.47–0.50; P
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- 2018
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6. High versus low attenuation thresholds to determine the solid component of ground-glass opacity nodules.
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Jae Ho Lee, Tae Hoon Kim, Sungsoo Lee, Kyunghwa Han, Min Kwang Byun, Yoon Soo Chang, Hyung Jung Kim, Geun Dong Lee, and Chul Hwan Park
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Medicine ,Science - Abstract
OBJECTIVES:To evaluate and compare the diagnostic accuracy of high versus low attenuation thresholds for determining the solid component of ground-glass opacity nodules (GGNs) for the differential diagnosis of adenocarcinoma in situ (AIS) from minimally invasive adenocarcinoma (MIA) and invasive adenocarcinoma (IA). METHODS:Eighty-six pathologically confirmed GGNs < 3 cm observed in 86 patients (27 male, 59 female; mean age, 59.3 ± 11.0 years) between January 2013 and December 2015 were retrospectively included. The solid component of each GGN was defined using two different attenuation thresholds: high (-160 Hounsfield units [HU]) and low (-400 HU). According to the presence or absence of solid portions, each GGN was categorized as a pure GGN or part-solid GGN. Solid components were regarded as indicators of invasive foci, suggesting MIA or IA. RESULTS:Among the 86 GGNs, there were 57 cases of IA, 19 of MIA, and 10 of AIS. Using the high attenuation threshold, 44 were categorized as pure GGNs and 42 as part-solid GGNs. Using the low attenuation threshold, 13 were categorized as pure GGNs and 73 as part-solid GGNs. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy for the invasive focus were 55.2%, 100%, 100%, 22.7%, and 60.4%, respectively, for the high attenuation threshold, and 93.4%, 80%, 97.2%, 61.5%, and 91.8%, respectively, for the low attenuation threshold. CONCLUSION:The low attenuation threshold was better than the conventional high attenuation threshold for determining the solid components of GGNs, which indicate invasive foci.
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- 2018
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7. The repeatability of computed tomography lung volume measurements: Comparisons in healthy subjects, patients with obstructive lung disease, and patients with restrictive lung disease.
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Jae Min Shin, Tae Hoon Kim, Seokjin Haam, Kyunghwa Han, Min Kwang Byun, Yoon Soo Chang, Hyung Jung Kim, and Chul Hwan Park
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Medicine ,Science - Abstract
In this study, we examined the repeatability of computed tomography (CT) lung volume measurements in healthy individuals and patients with obstructive and restrictive lung diseases. To do this, we retrospectively enrolled 200 healthy individuals (group 1), 100 patients with obstructive lung disease (group 2), and 100 patients with restrictive lung disease (group 3) who underwent two consecutive chest CT scans within a 1-year period. The CT lung volume was measured using a threshold-based, three-dimensional auto-segmentation technique at a default range from -200 to -1024 HU. The within-subject standard deviation, repeatability coefficient, within-subject coefficient variability, and intraclass correlation coefficient were evaluated. No significant differences were identified between the two consecutive CT lung volume measurements in any of the groups (p> 0.05). The within-subject standard deviations for groups 1, 2, and 3 were 441.1, 387.0, and 288.6, respectively, while the repeatability coefficients were 1222.6, 1072.6, and 800.1, respectively. The within-subject coefficient variabilities for groups 1, 2, and 3 were 0.097, 0.083, and 0.090, respectively, while the intraclass correlation coefficients were 0.818, 0.881, and 0.910, respectively. The two CT lung volume measurements showed excellent agreement in healthy individuals and patients with obstructive or restrictive lung disease. However, the repeatability was lower in healthy individuals than it was in patients with lung diseases.
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- 2017
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8. Effectiveness of proton pump inhibitor in unexplained chronic cough.
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Hye Jung Park, Yoo Mi Park, Jie-Hyun Kim, Hye Sun Lee, Hyung Jung Kim, Chul Min Ahn, and Min Kwang Byun
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Medicine ,Science - Abstract
Current guidelines recommend that patients with unexplained chronic cough undergo empirical proton pump inhibitor (PPI) treatment, but scientific evidence for this treatment is lacking. We investigated the effectiveness and appropriate dose of PPI therapy in chronic cough.We included 27 patients with unexplained chronic cough after excluding subjects with positive response to postnasal drip medication. Subjects were randomized to a placebo, standard, and high dose of PPI groups with blinding. The drug or placebo was administered orally for 8 weeks, and the Leicester Cough Questionnaire (LCQ) score and visual analogue scale (VAS) scores were collected.The LCQ score in the PPI group significantly improved from 0 weeks (11.4 ± 1.4) to 4 weeks (14.8 ± 1.4) and to 8 weeks (17.1 ± 1.4), whereas that in the placebo group did not improve from 0 weeks (13.7 ± 1.1) to 8 weeks (11.8 ± 1.4); the difference between the 2 groups was significant (P < 0.001). In subgroup analysis according to reflux, significant improvements in the LCQ score were observed in the PPI group regardless of reflux (P < 0.001 in the reflux group and P < 0.001 in the no reflux group, respectively; P = 0.188 between the 2 groups). In addition, improvements in LCQ and VAS scores between the standard- and high-dose PPI groups were not significantly different; however, adverse reactions were induced by only the high dose (16.7%).The results of this pilot study support the empirical use of the standard dose of PPI for 8 weeks in patients suffering from unexplained chronic cough regardless of whether reflux is present.ClinicalTrial.gov NCT01888549 www.clinicaltrials.gov; cris.nih.go.kr KCT0000543 cris.nih.go.kr/.
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- 2017
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9. Birt-Hogg-Dube syndrome prospectively detected by review of chest computed tomography scans.
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Hye Jung Park, Chul Hwan Park, Sang Eun Lee, Geun Dong Lee, Min Kwang Byun, Sungsoo Lee, Kyung-A Lee, Tae Hoon Kim, Seong Han Kim, Seo Yeon Yang, Hyung Jung Kim, and Chul Min Ahn
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Medicine ,Science - Abstract
Birt-Hogg-Dube syndrome (BHD) is a rare disorder caused by mutations in the gene that encodes folliculin (FLCN) and is inherited in an autosomal dominant manner. BHD is commonly accompanied by fibrofolliculomas, renal tumors, multiple pulmonary cysts, and spontaneous pneumothorax. The aim of this study was to detect BHD prospectively in patients undergoing chest computed tomography (CT) scans and to evaluate further the characteristics of BHD in Korea.We prospectively checked and reviewed the chest CT scans obtained for 10,883 patients at Gangnam Severance Hospital, Seoul, Korea, from June 1, 2015 to May 31, 2016. Seventeen patients met the study inclusion criteria and underwent screening for FLCN mutation to confirm BHD. We analyzed the characteristics of the patients confirmed to have BHD and those for a further 6 patients who had previously been described in Korea.Six (0.06%) of the 10,883 patients reviewed were diagnosed with BHD. There was no difference in demographic or clinical features between the patients with BHD (n = 6) and those without BHD (n = 11). Pneumothorax was present in 50% of the patients with BHD but typical skin and renal lesions were absent. The maximum size of the cysts in the BHD group (median 39.4 mm; interquartile range [IQR] 11.4 mm) was significantly larger than that in the non-BHD group (median 15.8 mm; IQR 7.8 mm; P = 0.001). Variable morphology was seen in 100.0% of the cysts in the BHD group but in only 18.2% of the cysts in the non-BHD group (P = 0.002). Nine (95%) of the total of 12 Korean patients with BHD had experienced pneumothorax. Typical skin and renal lesions were present in 20.0% of patients with BHD.Our findings suggest that BHD can be detected if chest CT scans are read in detail.
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- 2017
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10. Differences of lung microbiome in patients with clinically stable and exacerbated bronchiectasis.
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Min Kwang Byun, Joon Chang, Hyung Jung Kim, and Seok Hoon Jeong
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Medicine ,Science - Abstract
Molecular-based diagnostic techniques can compensate for the inherent limitations of culture-based microbiology and provide a more comprehensive description of an entire community of bacteria at a particular anatomical site. Using culture-independent DNA-based molecular techniques, the aim of the present study was to characterize, differentiate, and compare the composition of lower airway bacterial microbiome between clinically stable and acutely infected patients with bronchiectasis experiencing exacerbation.Patients with clinically stable bronchiectasis and those experiencing acutely exacerbated bronchiectasis were recruited. All patients underwent bronchoscopy. Paired sputum and bronchoalveolar lavage (BAL) samples were collected for microbiological tests. Molecular analysis was performed for BAL samples using 16S ribosomal RNA (rRNA) gene sequencing.The mean age of the 14 recruited patients was 60 years (range 42 to 78 years), and nine (64%) were female. Using quantitative culture and 16S rRNA sequencing, the common organisms identified from 14 BAL samples were Haemophilus influenzae, Pseudomonas aeruginosa and Moraxella catarrhalis, and Prevotella. Molecular techniques revealed Prevotella and Veillonella as potentially pathogenic anaerobic species. 16S rRNA gene sequencing yielded similar relative abundances and distributions of taxa in the stable and exacerbated bronchiectasis groups. Alpha diversity with richness, Simpson's and Shannon indices, and beta diversity using principal coordinate analysis revealed no significant differences in lung microbiome between patients with clinically stable and exacerbated bronchiectasis.Culture-based microbiological and molecular-based techniques did not reveal significant differences in the lung microbiome of patients who were clinically stable and those experiencing exacerbated bronchiectasis. Patient-specific microbial communities were dominated by one or several genera, regardless of clinical status. DNA sequencing could identify potentially pathogenic organisms unable to be identified using microbiological methods.
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- 2017
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11. Socioeconomic burden of influenza in the Republic of Korea, 2007-2010.
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Mina Suh, Dae Ryong Kang, Dong Han Lee, Yoon Jung Choi, Byongho Tchoe, Chung Mo Nam, Hyung Jung Kim, Jong Koo Lee, Byung Yool Jun, Yoosik Youm, Gwi-Nam Bae, Tae Yong Lee, Moon Shik Kim, Dong Chun Shin, and Changsoo Kim
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Medicine ,Science - Abstract
BACKGROUND: Although the socioeconomic burden of 2009 pandemic influenza A (H1N1) was considerable, no reliable estimates have been reported. Our aim was to compared medical costs and socioeconomic burden resulting from pandemic influenza A (H1N1) 2009 with that of previous seasonal influenza. METHODS: We estimated the medical costs and socioeconomic burden of influenza from May 2007 to April 2010. We used representative national data sources(data from the Health Insurance Review Agency, the National Health Insurance Corporation, the Korea Centers for Disease Control and Prevention, and the Korean National Statistics Office) including medical utilization, prescription of antivirals, and vaccination. Uncertainty of data was explored through sensitivity analysis using Monte Carlo simulation. RESULTS: Compared with the seasonal influenza, total medical costs (US$291.7 million) associated with pandemic (H1N1) 2009 increased more than 37-fold. Compared with the 2007-2008 season, outpatient diagnostic costs (US$135.3 million) were 773 times higher in the 2009-2010 season, and the mean diagnostic cost per outpatient visit was 58.8 times higher. Total socioeconomic burden of pandemic (H1N1) 2009 was estimated at US$1581.3 million (10%-90%: US$1436.0-1808.3 million) and those of seasonal influenza was estimated at US$44.7 million (10%-90%: US$32.4-57.9 million) in 2007-2008 season and US$42.3 million (10%-90%: US$31.5-53.8 million) in 2008-2009 season. Indirect costs accounted for 56.0% of total costs in pandemic (H1N1) 2009, and 66.48-68.09% in seasonal influenza. The largest contributors to total burden were productivity losses of caregiver in pandemic (H1N1) 2009, and productivity losses due to morbidity of outpatient in seasonal influenza. CONCLUSIONS: In the Republic of Korea, socioeconomic burden of pandemic (H1N1) 2009 were considerably higher than burden of the previous two influenza seasons, primarily because of high diagnostic costs and longer sick leave.
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- 2013
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12. Design of Optimized Coded LFM Waveform for Spectrum Shared Radar System
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Dong-Hoon Kim, Hyung-Jung Kim, and Jae-Han Lim
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Spectrum Shared Radar Systems (SSRS) ,orthogonal waveforms ,code diversity ,optimized coded LFM ,Chemical technology ,TP1-1185 - Abstract
To meet the increasing demands for remote sensing, a number of radar systems using Linear Frequency Modulation (LFM) waveforms have been deployed, causing the problem of depleting frequency resources. To address this problem, several researchers have proposed the Spectrum Shared Radar System (SSRS) in which multiple radars share the same frequency band to transmit and receive their own signals. To mitigate the interferences caused by the signal transmission by other radars, SSRS employs orthogonal waveforms that inherit the orthogonality of the waveforms from orthogonal codes. However, the inherited orthogonality of the codes is significantly reduced when incorporating LFM waveforms with the codes. To solve this problem, in this paper, we propose a novel but simple scheme for generating a set of optimized coded LFM waveforms via new optimization framework. In the optimization framework, we minimize the weighted sum of autocorrelation sidelobe peaks (ASP) and cross-correlation peaks (CP) of the coded LFM waveforms to maximize the orthogonality of the waveforms. Through computer simulations, we show that the waveforms generated by the proposed scheme outperform the waveforms created by previous proposals in terms of ASP and CP.
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- 2021
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13. Calculation of AeroMACS Spectrum Requirements Based on Traffic Simulator
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Hong-Gi Shin, Hyung-Jung Kim, Sang-Wook Lee, Hyun-Goo Yoon, and Yong-Hoon Choi
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AeroMACS ,spectrum requirement ,airport traffic model ,ITU-R M.1768-1 ,service categories ,Chemical technology ,TP1-1185 - Abstract
In this paper, we propose a methodology for calculating the necessary spectrum requirements of aeronautical mobile airport communication system (AeroMACS) to provide various airport communication services. To accurately calculate the spectrum requirement, it is necessary to evaluate the AeroMACS traffic demand of the peak time and statistical data on the packet traffic generated at the airport. Because there is no AeroMACS traffic model and real trace data, we have developed the AeroMACS traffic simulator based on the report of Single European Sky Air Traffic Management Research (SESAR). To calculate the spectrum requirements, the AeroMACS traffic simulator is combined with the methodology of ITU-R M.1768-1. The developed traffic simulator reflects AeroMACS traffic priorities and can generate the required traffic according to its location in the airport. We observed the spectrum requirement by changing the number of sectors and the spectral efficiency. To show the feasibility of our methodology, we applied it to the case of Incheon International Airport in Korea. The simulation results show that the average bandwidth of 0.94 MHz is required in the ground area and 8.59 MHz is required in the entire airport.
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- 2021
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14. Appropriate Smart Factory : Demonstration of Applicability to Industrial Safety
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Kui-Kam Kwon, SungJin Hong, Gyu Wha Lee, Hyung-Jung Kim, Su-Young Park, Won-Jae Yun, Guyeop Jung, Hyunsu Lee, Young-Gyun Kim, Sae-Jin Park, Woo-Kyun Jeong, Ying-Jun Quan, and Sung-Hoon Ahn
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Engineering ,business.industry ,Smart factory ,Systems engineering ,Monitoring system ,General Medicine ,business - Abstract
As industrial safety increases, various industrial accident prevention technologies using smart factory technology are being studied. However, small and medium enterprises (SMEs), which account for the majority of industrial accidents, are having difficulties in preventing industrial accidents by applying these smart factory technologies due to practical problems. In this study, customized monitoring and warning systems for each type of industrial accident were developed and applied to the actual field. Through this, we demonstrated industrial accident prevention technology through appropriate smart factory technology used by SMEs. A customized monitoring system using vision, current, temperature, and gas sensors was established for the four major disaster types: worker body access, short circuit and overcurrent, fire and burns due to high temperature, and emission of hazardous gas. In addition, a notification method suitable for each work environment was applied so that the monitored risk factors could be recognized quickly, and real-time data transmission and display enabled workers and managers to understand the disaster risk effectively. Through the application and demonstration of these appropriate smart factory technologies, the spread of these industrial safety technologies is to be discussed.
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- 2021
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15. FEF25-75% Values in Patients with Normal Lung Function Can Predict the Development of Chronic Obstructive Pulmonary Disease
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Hyung Jung Kim, Min Kwang Byun, Jae Hwa Cho, Hye Jung Park, Taehee Kim, Do Sun Kwon, and Yong Jun Choi
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medicine.medical_specialty ,COPD ,Vital capacity ,Proportional hazards model ,business.industry ,Hazard ratio ,Pulmonary disease ,General Medicine ,Normal lung function ,respiratory system ,medicine.disease ,respiratory tract diseases ,Pulmonary function testing ,03 medical and health sciences ,0302 clinical medicine ,030228 respiratory system ,Internal medicine ,medicine ,Cardiology ,In patient ,030212 general & internal medicine ,business - Abstract
Purpose The forced mid-expiratory flow (FEF25-75%) value is a potentially sensitive marker of obstructive peripheral airflow. We aimed to assess whether FEF25-75% can be an early predictor of chronic obstructive pulmonary disease (COPD). Patients and Methods Between July 1, 2007 and June 31, 2009, we identified 3624 patients who underwent a pulmonary function test (PFT) in Gangnam Severance Hospital. We selected 307 patients aged over 40 years without COPD who had normal PFT results at baseline and who had follow-up PFT records more than 1 year later. A FEF25-75% z-score less than -0.8435 was considered low. We defined COPD as a forced expiratory volume in one second/forced vital capacity value of less than 0.7 before July 31, 2019. Results Among 307 patients, 91 (29.6%) had low FEF25-75% at baseline. After 10 years, the incidence rate of COPD in the low FEF25-75% group was significantly higher than that in the normal FEF25-75% group (41.8% vs 7.4%; P-value
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- 2020
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16. Image-based failure detection for material extrusion process using a convolutional neural network
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Sung-Hoon Ahn, Hyunsu Lee, Hyung-Jung Kim, and Ji Soo Kim
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0209 industrial biotechnology ,Contextual image classification ,business.industry ,Computer science ,Mechanical Engineering ,Deep learning ,Process (computing) ,3D printing ,02 engineering and technology ,Sample (graphics) ,Convolutional neural network ,Industrial and Manufacturing Engineering ,Computer Science Applications ,020901 industrial engineering & automation ,Control and Systems Engineering ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Computer vision ,Extrusion ,Artificial intelligence ,business ,Software ,Image based - Abstract
The material extrusion (ME) process is one of the most widely used 3D printing processes, especially considering its use of inexpensive materials. However, the error known as the “spaghetti-shape error,” related to filament tangling, is a common problem associated with the ME process. Once occurring, this issue, which consumes both time and materials, requires a restart of the entire process. In order to prevent this, the user must constantly monitor the process. In this research, a failure detection method which uses a webcam and deep learning is developed for the ME process. The webcam captures images and then analyzes them by machine learning based on a convolutional neural network (CNN), showing outstanding performance in both image classification and the recognition of objects. Sample images were trained based on a modified Visual Geometry Group Network (VGGNet) model and the trained model was evaluated, resulting in 97% accuracy. The pre-trained model was tested on a 3D printer monitoring system for its ability to recognize the “spaghetti-shape-error” and was able to detect 96% of abnormal deposition processes. The proposed method can analyze the ME process in real time and informs the user or halts the process when abnormal printing is detected.
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- 2020
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17. Design of Optimized Coded LFM Waveform for Spectrum Shared Radar System
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Jae-Han Lim, Dong-Hoon Kim, and Hyung-Jung Kim
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Computer science ,Frequency band ,Chemical technology ,Autocorrelation ,Spectrum (functional analysis) ,optimized coded LFM ,TP1-1185 ,Biochemistry ,Radar systems ,Atomic and Molecular Physics, and Optics ,Article ,Analytical Chemistry ,code diversity ,Set (abstract data type) ,Orthogonality ,Computer Science::Programming Languages ,Waveform ,Spectrum Shared Radar Systems (SSRS) ,Electrical and Electronic Engineering ,Instrumentation ,Algorithm ,Frequency modulation ,orthogonal waveforms - Abstract
To meet the increasing demands for remote sensing, a number of radar systems using Linear Frequency Modulation (LFM) waveforms have been deployed, causing the problem of depleting frequency resources. To address this problem, several researchers have proposed the Spectrum Shared Radar System (SSRS) in which multiple radars share the same frequency band to transmit and receive their own signals. To mitigate the interferences caused by the signal transmission by other radars, SSRS employs orthogonal waveforms that inherit the orthogonality of the waveforms from orthogonal codes. However, the inherited orthogonality of the codes is significantly reduced when incorporating LFM waveforms with the codes. To solve this problem, in this paper, we propose a novel but simple scheme for generating a set of optimized coded LFM waveforms via new optimization framework. In the optimization framework, we minimize the weighted sum of autocorrelation sidelobe peaks (ASP) and cross-correlation peaks (CP) of the coded LFM waveforms to maximize the orthogonality of the waveforms. Through computer simulations, we show that the waveforms generated by the proposed scheme outperform the waveforms created by previous proposals in terms of ASP and CP.
- Published
- 2021
18. Colistin monotherapy versus colistin/rifampicin combination therapy in pneumonia caused by colistin-resistant Acinetobacter baumannii: A randomised controlled trial
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Hyung Jung Kim, Seok Hoon Jeong, Jae Hwa Cho, Hye Jung Park, Sang Hoon Han, and Min Kwang Byun
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Acinetobacter baumannii ,Male ,0301 basic medicine ,law.invention ,0302 clinical medicine ,Randomized controlled trial ,law ,Drug Resistance, Multiple, Bacterial ,polycyclic compounds ,Immunology and Allergy ,030212 general & internal medicine ,Aged, 80 and over ,biology ,Middle Aged ,Anti-Bacterial Agents ,Drug Therapy, Combination ,Female ,Rifampin ,medicine.drug ,Adult ,Microbiology (medical) ,medicine.medical_specialty ,Prognostic factor ,Adolescent ,Combination therapy ,030106 microbiology ,Immunology ,Microbial Sensitivity Tests ,Microbiology ,Young Adult ,03 medical and health sciences ,Internal medicine ,medicine ,Humans ,Etest ,Aged ,Colistin ,business.industry ,Pneumonia ,biochemical phenomena, metabolism, and nutrition ,equipment and supplies ,bacterial infections and mycoses ,biology.organism_classification ,medicine.disease ,bacteria ,business ,Rifampicin - Abstract
Objectives The aim of this study was to confirm the synergistic effect of colistin/rifampicin combination therapy compared with colistin monotherapy in pneumonia caused by colistin-resistant Acinetobacter baumannii (CoRAB). The utility of the Etest was also assessed. Methods Nine subjects with pneumonia caused by CoRAB were enrolled from 20 July 2016 to 21 June 2018. Subjects were randomised to colistin/rifampicin combination therapy or colistin monotherapy. After exclusion of one patient who dropped out, the microbiological response (MR) and clinical response (CR) on Day 14 and mortality on Day 30 were assessed. Etest was conducted using CoRAB isolated at study enrolment. Results The MR rate in the colistin/rifampicin combination group (100.0%) was better than that in the colistin group (40.0%), however the difference was not statistically significant (P = 0.196). The CR rate was not significantly different between the two groups. The MR (100.0%) and CR (100.0%) rates in subjects with ‘partial synergy’ as shown by Etest were higher than those (25.0% and 50.0%, respectively) in subjects with ‘indifferent’ results (i.e. no synergistic effect), however the difference was not statistically significant (P = 0.143 and 0.429, respectively). Mortality occurred in two subjects with ‘indifferent’ results by Etest. Conclusions Colistin/rifampicin combination therapy may have potential to achieve MR in pneumonia caused by CoRAB; however, achieving CR with this treatment is doubtful. ‘Partial synergy’ of colistin and rifampicin, as shown by Etest, may be a good prognostic factor [ClinicalTrial.gov ID: NCT03622918].
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- 2019
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19. Recurrent Pancreatitis Caused by Afferent Loop Syndrome with Pathologic Features of Type II Autoimmune Pancreatitis
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김해인 ( Hae In Kim ), 김명환 ( Myung-hwan Kim ), 홍승모 ( Seung-mo Hong ), 백지연 ( Ji Yeon Back ), 박예은 ( Yae Eun Park ), 김형중 ( Hyung-jung Kim ), and 이세희 ( Se Hee Lee )
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03 medical and health sciences ,0302 clinical medicine ,Traditional medicine ,business.industry ,Medicine ,030211 gastroenterology & hepatology ,business - Abstract
재발성 췌장염의 드문 원인으로 들창자증후군과 동반된 췌장염이 있을 수 있다. 따라서 원인 불명의 반복적인 췌장염 환자에서 수술력을 확인하고, 기존의 영상 소견을 종합하여 원인을 찾는 시도가 필요하며, 유발 원인에 따라 적절한 치료가 이루어져야 한다. 제2형 AIP는 반복적인 급성췌장염의 형태로도 나타날 수 있어 젊은 환자에서 전형적인 췌장영상 소견과 조직 소견이 동반된 경우 감별해야 하는 질환 중 하나이지만 종합적인 임상적인 판단이 최종 진단에 가장 중요하다.
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- 2019
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20. Calculation of AeroMACS Spectrum Requirements Based on Traffic Simulator
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Sangwook Lee, Yong-Hoon Choi, Hyung-Jung Kim, Hong-Gi Shin, and Hyungoo Yoon
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Computer science ,Network packet ,airport traffic model ,Chemical technology ,Communication ,Real-time computing ,Air traffic management ,Bandwidth (signal processing) ,service categories ,Spectral efficiency ,TP1-1185 ,Communications system ,Biochemistry ,International airport ,Atomic and Molecular Physics, and Optics ,ITU-R M.1768-1 ,Analytical Chemistry ,AeroMACS ,spectrum requirement ,Electrical and Electronic Engineering ,Single European Sky ,Instrumentation ,TRACE (psycholinguistics) - Abstract
In this paper, we propose a methodology for calculating the necessary spectrum requirements of aeronautical mobile airport communication system (AeroMACS) to provide various airport communication services. To accurately calculate the spectrum requirement, it is necessary to evaluate the AeroMACS traffic demand of the peak time and statistical data on the packet traffic generated at the airport. Because there is no AeroMACS traffic model and real trace data, we have developed the AeroMACS traffic simulator based on the report of Single European Sky Air Traffic Management Research (SESAR). To calculate the spectrum requirements, the AeroMACS traffic simulator is combined with the methodology of ITU-R M.1768-1. The developed traffic simulator reflects AeroMACS traffic priorities and can generate the required traffic according to its location in the airport. We observed the spectrum requirement by changing the number of sectors and the spectral efficiency. To show the feasibility of our methodology, we applied it to the case of Incheon International Airport in Korea. The simulation results show that the average bandwidth of 0.94 MHz is required in the ground area and 8.59 MHz is required in the entire airport.
- Published
- 2021
21. Low Alanine Aminotransferase as a Risk Factor for Chronic Obstructive Pulmonary Disease in Males: A Retrospective Population-based Cohort Study
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Yong Jun Choi, Do Sun Kwon, Taehee Kim, Jae Hwa Cho, Hyung Jung Kim, Min Kwang Byun, and Hye Jung Park
- Abstract
Alanine aminotransferase (ALT) levels reflect skeletal muscle volume and general performance scales, which are significantly associated with chronic obstructive pulmonary disease (COPD) development and prognosis. The aim of this study was to investigate the ALT levels as a risk factor for COPD development. This 13-year population-based retrospective cohort observational study included patients registered in the health check-up cohort database of the Korean National Health Insurance Service. A total of 422,452 participants were analysed. We classified groups according to the baseline ALT levels (groups 1–5: ALT (IU/L)
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- 2021
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22. Low alanine aminotransferase as a risk factor for chronic obstructive pulmonary disease in males
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Hye Jung Park, Jae Hwa Cho, Yong Jun Choi, Hyung Jung Kim, Taehee Kim, Min Kwang Byun, and Do Sun Kwon
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Adult ,Male ,medicine.medical_specialty ,Epidemiology ,Science ,Population ,030204 cardiovascular system & hematology ,Gastroenterology ,Article ,03 medical and health sciences ,Pulmonary Disease, Chronic Obstructive ,0302 clinical medicine ,Internal medicine ,Medicine ,Humans ,Risk factor ,education ,Retrospective Studies ,COPD ,education.field_of_study ,Sex Characteristics ,Multidisciplinary ,business.industry ,Proportional hazards model ,Incidence (epidemiology) ,Chronic obstructive pulmonary disease ,Hazard ratio ,Alanine Transaminase ,Middle Aged ,medicine.disease ,Prognosis ,Confidence interval ,030228 respiratory system ,Risk factors ,Female ,business ,Biomarkers ,Cohort study - Abstract
Alanine aminotransferase (ALT) levels reflect skeletal muscle volume and general performance, which are associated with chronic obstructive pulmonary disease (COPD) development and prognosis. This study aimed to investigate ALT levels as a risk factor for COPD development. This 13-year population-based retrospective observational cohort study included 422,452 participants for analysis. We classified groups according to the baseline ALT levels (groups 1–5: ALT (IU/L)
- Published
- 2021
23. The design method and performance analysis of RF subsampling frontend for SDR/CR receivers
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Hyung-Jung Kim, Jin-Up Kim, Jae-Hyung Kim, Hongmei Wang, and In-Sung Lee
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Analog to digital converters -- Design and construction ,Business ,Computers ,Electronics ,Electronics and electrical industries - Published
- 2010
24. Effect of Asthma and Asthma Medication on the Prognosis of Patients with COVID-19
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Jae Hyun Lee, Ju-Young Park, Hyung Jung Kim, Hye Sun Lee, Jung Won Park, Jeung Yoon Song, Yong Jun Choi, Min Kwang Byun, Jae Hwa Cho, Jin Suk Suh, and Hye Jung Park
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Pulmonary and Respiratory Medicine ,medicine.medical_specialty ,Coronavirus disease 2019 (COVID-19) ,business.industry ,Mortality rate ,MEDLINE ,Retrospective cohort study ,Disease ,medicine.disease ,respiratory tract diseases ,03 medical and health sciences ,0302 clinical medicine ,030228 respiratory system ,immune system diseases ,Internal medicine ,Medicine ,Original Article ,030212 general & internal medicine ,Diagnosis code ,Young adult ,business ,Asthma - Abstract
Background Coronavirus disease (COVID-19) has rapidly spread worldwide. However, the effects of asthma, asthma medication, and asthma severity on the clinical outcomes of COVID-19 have not yet been established. Methods The study included 7590 de-identified patients, who were confirmed to have COVID-19 using the severe acute respiratory syndrome-coronavirus-2 RNA–polymerase chain reaction tests conducted up to 15th May 2020; and we used the linked-medical claims data provided by the Health Insurance Review and Assessment Service. Asthma and asthma severity (step suggested by GINA) was defined using the diagnostic code and history of asthma medication usage. Results Among 7590 COVID-19 patients, 218 (2.9%) had underlying asthma. The total medical cost associated with COVID-19 patients with underlying asthma was significantly higher than that of other patients. Mortality rate for COVID-19 patients with underlying asthma (7.8%) was significantly higher than that of other patients (2.8%; p, Asthma increases the total medical cost burden and mortality rate associated with COVID-19. Asthma patients should not be concerned about using asthma medication during the COVID-19 pandemic, except for the use of oral short-acting β2-agonists.
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- 2020
25. FEF
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Do Sun, Kwon, Yong Jun, Choi, Tae Hee, Kim, Min Kwang, Byun, Jae Hwa, Cho, Hyung Jung, Kim, and Hye Jung, Park
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Pulmonary Disease, Chronic Obstructive ,Forced Expiratory Volume ,respiratory function tests ,Vital Capacity ,Humans ,COPD ,respiratory system ,Lung ,tobacco ,respiratory tract diseases ,Aged ,Original Research - Abstract
Purpose The forced mid-expiratory flow (FEF25-75%) value is a potentially sensitive marker of obstructive peripheral airflow. We aimed to assess whether FEF25-75% can be an early predictor of chronic obstructive pulmonary disease (COPD). Patients and Methods Between July 1, 2007 and June 31, 2009, we identified 3624 patients who underwent a pulmonary function test (PFT) in Gangnam Severance Hospital. We selected 307 patients aged over 40 years without COPD who had normal PFT results at baseline and who had follow-up PFT records more than 1 year later. A FEF25-75% z-score less than −0.8435 was considered low. We defined COPD as a forced expiratory volume in one second/forced vital capacity value of less than 0.7 before July 31, 2019. Results Among 307 patients, 91 (29.6%) had low FEF25-75% at baseline. After 10 years, the incidence rate of COPD in the low FEF25-75% group was significantly higher than that in the normal FEF25-75% group (41.8% vs 7.4%; P-value
- Published
- 2020
26. Broken stitch detection method for sewing operation using CNN feature map and image-processing techniques
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Jae-Won Lee, Young-Chul Park, Woo-Kyun Jung, Hyung-Jung Kim, and Sung-Hoon Ahn
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business.industry ,Computer science ,Deep learning ,Computation ,General Engineering ,Image processing ,Convolutional neural network ,Computer Science Applications ,Image (mathematics) ,Set (abstract data type) ,Artificial Intelligence ,Feature (computer vision) ,Computer vision ,Artificial intelligence ,business ,Representation (mathematics) - Abstract
The inspection of sewing defects is an essential step in the quality assurance of garment manufacturing. Although traditional automated defect detection applications have shown good performance, these methods are usually configured with handcrafted features designed by a human operator. Recently, deep learning methods that include Convolutional Neural Networks (CNNs) have demonstrated excellent performance in a wide variety of computer-vision applications. To take advantage of the CNN’s feature representation, the direct utilization of feature maps from the convolutional layers as universal feature descriptors has been studied. In this paper, we propose a sewing defect detection method using a CNN feature map extracted from the initial layers of a pre-trained VGG-16 to detect a broken stitch from a captured image of a sewing operation. To assess the effectiveness of the proposed method, experiments were conducted on a set of sewing images, including normal images, their synthetic defects, and rotated images. As a result, the proposed method detected true defects with 92.3% accuracy. Moreover, additional conditions for computing devices and deep learning libraries were investigated to reduce the computing time required for real-time computation. Using a general and cheap single-board computer with resizing the image and utilizing a lightweight deep learning library, the computing time was 0.22 s. The results confirm the feasibility of the proposed method’s performance as an appropriate manufacturing technology for garment production.
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- 2022
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27. Regular follow-up visits reduce the risk for asthma exacerbation requiring admission in Korean adults with asthma
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Kwang-Ha Yoo, Min Kwang Byun, Hyung Jung Kim, Hye Won Bae, Bo Yeon Kim, Hye Jung Park, Chul Min Ahn, Kyungjoo Kim, and Chin Kook Rhee
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lcsh:Immunologic diseases. Allergy ,medicine.medical_specialty ,Allergy ,Exacerbation ,Lower risk ,law.invention ,03 medical and health sciences ,0302 clinical medicine ,law ,medicine ,030212 general & internal medicine ,Asthma ,business.industry ,Research ,Attendance ,General Medicine ,Odds ratio ,medicine.disease ,Intensive care unit ,Confidence interval ,030228 respiratory system ,Emergency medicine ,business ,lcsh:RC581-607 ,Compliance - Abstract
Background Asthma requires regular follow-up visits and sustained medication use. Although several studies have reported the importance of adherence to medication and compliance with the treatment, none to date have reported the importance of regular follow-up visits. We investigated the effects of regular clinical visits on asthma exacerbation. Methods We used claims data in the national medical insurance review system provided by the Health Insurance Review and Assessment Service of Korea. We included subjects aged ≥ 15 years with a diagnosis of asthma, and who were prescribed asthma-related medication, from July 2013 to June 2014. Regular visitors (frequent visitors) were defined as subjects who visited the hospital for follow-up of asthma three or more times per year. Results Among 729,343 subjects, 496,560 (68.1%) were classified as regular visitors. Old age, male sex, lack of medical aid insurance, attendance of a tertiary hospital, a high Charlson comorbidity index, and a history of admission for exacerbated asthma in the previous year were significant determining factors for regular visitor status. When we adjusted for all these factors, frequent visitors showed a lower risk of asthma exacerbation requiring general ward admission (odds ratio [OR] 0.48; 95% confidence interval [CI] 0.47–0.50; P
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- 2018
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28. Repeated Measurement of Fractional Exhaled Nitric Oxide Is Not Essential for Asthma Screening
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Lee Hs, Min Kwang Byun, Chul Min Ahn, Hyung Jung Kim, Yoon Hee Kim, Yang Sy, Sae Hoon Kim, and Hye Jung Park
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Adult ,Male ,medicine.medical_specialty ,Intraclass correlation ,Immunology ,Asthma screening ,Nitric Oxide ,Sensitivity and Specificity ,03 medical and health sciences ,0302 clinical medicine ,Respiratory medicine department ,Internal medicine ,medicine ,Humans ,Immunology and Allergy ,In patient ,030212 general & internal medicine ,Lung ,Lung function ,Retrospective Studies ,Asthma ,Reproducibility ,business.industry ,Reproducibility of Results ,Middle Aged ,respiratory system ,medicine.disease ,respiratory tract diseases ,Breath Tests ,030228 respiratory system ,Exhalation ,Exhaled nitric oxide ,Female ,business - Abstract
BACKGROUND AND OBJETIVE Older guidelines recommend that fractional exhaled nitric oxide (FeNO) should be checked more than twice during the same session to confirm an asthma diagnosis. Recent studies show the excellent reproducibility of FeNO measurements. Objetive: We aimed to determine whether repeated FeNO measurements during the same session are necessary for asthma screening. MATERIAL AND METHODS We retrospectively reviewed the electronic medical records of adult outpatients who visited the respiratory medicine department for diagnosis of asthma and assessed FeNO measurements obtained from June 2016 to July 2017. RESULTS Of the 132 patients enrolled, 79 (59.8%) were diagnosed with asthma. Repeated FeNO measurements taken during the same session showed high reproducibility (intraclass correlation coefficient >0.9; P 0.9; P
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- 2018
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29. Efficacy of adjuvant chemotherapy for completely resected stage IB non-small cell lung cancer: a retrospective study
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Min Kwang Byun, Hei Cheul Jeung, Jae Yong Cho, Hye Jung Park, Heae Surng Park, Sungsoo Lee, Hyung Jung Kim, and Yoon Jin Cha
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Pulmonary and Respiratory Medicine ,Oncology ,medicine.medical_specialty ,Adjuvant chemotherapy ,business.industry ,Lymphovascular invasion ,Hazard ratio ,Cancer ,Retrospective cohort study ,030204 cardiovascular system & hematology ,medicine.disease ,Confidence interval ,03 medical and health sciences ,0302 clinical medicine ,030220 oncology & carcinogenesis ,Internal medicine ,medicine ,Original Article ,business ,Lung cancer ,Lung cancer screening - Abstract
Background: Lung cancer is being increasingly detected in the early stages, highlighting the importance of lung cancer screening. However, there is no consensus on the post-operative management of stage IB non-small cell lung cancer (NSCLC). Therefore, this study aimed to identify the predictive factors for prognosis of stage IB NSCLC and determine the efficacy of adjuvant chemotherapy on recurrence and survival. Methods: We enrolled 89 patients with stage IB NSCLC who underwent complete resection surgery at Gangnam Severance Hospital from Jan 2008 to Dec 2014. As per the National Comprehensive Cancer Network guidelines, patients were considered to be at high risk when they showed poorly differentiated tumors, lymphovascular invasion, tumor size >4 cm, and visceral pleural invasion (VPI). Results: Among the 89 patients, 27 underwent adjuvant chemotherapy. Young patients or patients with squamous cell lung cancer received adjuvant chemotherapy frequently. Adjuvant chemotherapy was not a significant factor for disease-free survival and overall survival. Adjuvant chemotherapy did not show a significant protective effect for survival, even for high-risk patients. However, VPI was a significant risk factor for disease-free survival [hazard ratio (HR): 7.051; 95% confidence interval (CI): 1.570–31.659; P=0.011] and overall survival (HR: 8.289; 95% CI: 1.036–66.307; P=0.046), even after adjustment for various factors. Conclusions: Adjuvant chemotherapy does not affect the prognosis of stage IB NSCLC, even in high-risk patients. Additionally, VPI is a strong prognostic factor of stage IB NSCLC.
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- 2018
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30. Hepatitis C virus p7 induces mitochondrial depolarization of isolated liver mitochondria
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Deok Gyun You, Gi Young Lee, Hye Ra Lee, Hyung Jung Kim, Won Ki Kim, and Young Do Yoo
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Male ,0301 basic medicine ,Cancer Research ,Hepatitis C virus ,Cell ,Mitochondria, Liver ,Mitochondrion ,Biology ,medicine.disease_cause ,Biochemistry ,Viral Proteins ,03 medical and health sciences ,Adenosine Triphosphate ,Genetics ,medicine ,Animals ,Molecular Biology ,Membrane Potential, Mitochondrial ,030102 biochemistry & molecular biology ,ATP synthase ,Endoplasmic reticulum ,virus diseases ,Depolarization ,Cell cycle ,digestive system diseases ,Cell biology ,Mice, Inbred C57BL ,030104 developmental biology ,medicine.anatomical_structure ,Oncology ,Apoptosis ,biology.protein ,Molecular Medicine ,Acids - Abstract
Hepatitis C virus (HCV)‑encoded protein p7 is a viroporin that acts as an ion channel and is indispensable for HCV particle production. Although the main target of HCV p7 is the endoplasmic reticulum, it also targets mitochondria. HCV‑infected cells show mitochondrial depolarization and ATP depletion; however, the function of HCV p7 in mitochondria is not fully understood. The present study demonstrated that treatment of isolated mouse liver mitochondria with the synthesized HCV p7 protein induced mitochondrial dysfunction. It also demonstrated that HCV p7 targeted isolated mouse liver mitochondria and induced mitochondrial depolarization. In addition, HCV p7 triggered matrix acidification and, ultimately, a decrease in ATP synthesis in isolated mitochondria. These findings indicate that targeting of mitochondria by HCV p7 in infected cells causes mitochondrial dysfunction to support HCV particle production. The present study provided evidence for the role of HCV p7 in mitochondria, and may lead to the development of novel strategies for HCV therapy.
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- 2017
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31. Sarcopenia correlates with systemic inflammation in COPD
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Min Kwang Byun, Chul Min Ahn, Hyung Jung Kim, Eun Na Cho, and Joon Chang
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Male ,Sarcopenia ,Health Status ,Comorbidity ,Systemic inflammation ,Pulmonary Disease, Chronic Obstructive ,0302 clinical medicine ,Risk Factors ,Electric Impedance ,Prevalence ,Outpatient clinic ,Mass index ,030212 general & internal medicine ,Lung ,Wasting ,Original Research ,systemic inflammation ,Aged, 80 and over ,handgrip strength ,education.field_of_study ,COPD ,Exercise Tolerance ,Hand Strength ,Age Factors ,General Medicine ,Middle Aged ,Female ,Inflammation Mediators ,medicine.symptom ,Bioelectrical impedance analysis ,Adult ,medicine.medical_specialty ,Population ,Walk Test ,International Journal of Chronic Obstructive Pulmonary Disease ,03 medical and health sciences ,Internal medicine ,Republic of Korea ,medicine ,Humans ,Muscle, Skeletal ,education ,Aged ,Inflammation ,Chi-Square Distribution ,Interleukin-6 ,Tumor Necrosis Factor-alpha ,business.industry ,muscle wasting ,medicine.disease ,Cross-Sectional Studies ,Logistic Models ,030228 respiratory system ,Multivariate Analysis ,business ,human activities ,Biomarkers - Abstract
Min Kwang Byun,1 Eun Na Cho,1 Joon Chang,2 Chul Min Ahn,1 Hyung Jung Kim1 1Division of Pulmonology, Department of Internal Medicine, Gangnam Severance Hospital, 2Division of Pulmonology, Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea Background: Muscle wasting and chronic inflammation are predominant features of patients with COPD. Systemic inflammation is associated with an accelerated decline in lung function. In this study, the prevalence of sarcopenia and the relationships between sarcopenia and systemic inflammations in patients with stable COPD were investigated. Materials and methods: In a cross-sectional design, muscle strength and muscle mass were measured by handgrip strength (HGS) and bioelectrical impedance analysis in 80 patients with stable COPD. Patients (≥40 years old) diagnosed with COPD were recruited from outpatient clinics, and then COPD stages were classified. Sarcopenia was defined as the presence of both low muscle strength (by HGS) and low muscle mass (skeletal muscle mass index [SMMI]). Levels of circulating inflammatory biomarkers (IL-6 and high-sensitivity TNFα [hsTNFα]) were measured. Results: Sarcopenia was prevalent in 20 (25%) patients. Patients with sarcopenia were older, had lower body mass index, and a higher percentage of cardiovascular diseases. In addition, they had significantly higher modified Medical Research Council scores and lower 6-minute walk distance than those without sarcopenia. HGS was significantly correlated with age, modified Medical Research Council score, and COPD Assessment Test scores. Both HGS and SMMI had associations with IL-6 and hsTNFα (HGS, r=-0.35, P=0.002; SMMI, r=-0.246, P=0.044) level. In multivariate analysis, old age, lower body mass index, presence of cardiovascular comorbidities, and higher hsTNFα levels were significant determinants for sarcopenia in patients with stable COPD. Conclusion: Sarcopenia is very common in patients with stable COPD, and is associated with more severe dyspnea-scale scores and lower exercise tolerance. Systemic inflammation could be an important contributor to sarcopenia in the stable COPD population. Keywords: sarcopenia, muscle wasting, handgrip strength, systemic inflammation, COPD
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- 2017
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32. A Low-Cost Vision-Based Monitoring of Computer Numerical Control (CNC) Machine Tools for Small and Medium-Sized Enterprises (SMEs)
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In-Gyu Choi, Woo-Kyun Jung, Sung-Hoon Ahn, and Hyung-Jung Kim
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0209 industrial biotechnology ,optical character recognition ,business.product_category ,Computer science ,open-source software ,small and medium-sized enterprises ,02 engineering and technology ,lcsh:Chemical technology ,Biochemistry ,Article ,Analytical Chemistry ,020901 industrial engineering & automation ,0202 electrical engineering, electronic engineering, information engineering ,lcsh:TP1-1185 ,Factory ,Environmental impact assessment ,Electrical and Electronic Engineering ,Industrial Revolution ,Instrumentation ,Productivity ,smart factory ,Atomic and Molecular Physics, and Optics ,Manufacturing engineering ,Machine tool ,machine tool monitoring ,Numerical control ,Factory (object-oriented programming) ,020201 artificial intelligence & image processing ,business - Abstract
In the new era of manufacturing with the Fourth Industrial Revolution, the smart factory is getting much attention as a solution for the factory of the future. Despite challenges in small and medium-sized enterprises (SMEs), such as short-term strategies and labor-intensive with limited resources, they have to improve productivity and stay competitive by adopting smart factory technologies. This study presents a novel monitoring approach for SMEs, KEM (keep an eye on your machine), and using a low-cost vision, such as a webcam and open-source technologies. Mainly, this idea focuses on collecting and processing operational data using cheaper and easy-to-use components. A prototype was tested with the typical 3-axis computer numerical control (CNC) milling machine. From the evaluation, availability of using a low-cost webcam and open-source technologies for monitoring of machine tools was confirmed. The results revealed that the proposed system is easy to integrate and can be conveniently applied to legacy machine tools on the shop floor without a significant change of equipment and cost barrier, which is less than $500 USD. These benefits could lead to a change of monitoring operations to reduce time in operation, energy consumption, and environmental impact for the sustainable production of SMEs.
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- 2019
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33. Positive Effects of the National Cigarette Price Increase Policy on Smoking Cessation in South Korea
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Taehee Kim, Min Kwang Byun, Hyung Jung Kim, Do Sun Kwon, Hye Sun Lee, and Hye Jung Park
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Pulmonary and Respiratory Medicine ,National Health and Nutrition Examination Survey ,business.industry ,medicine.medical_treatment ,Smoking ,Primary education ,Odds ratio ,Miscellaneous ,03 medical and health sciences ,0302 clinical medicine ,Infectious Diseases ,Policy ,030228 respiratory system ,Quartile ,South Korea ,medicine ,Cigarette Price ,University education ,Smoking cessation ,Household income ,Original Article ,030212 general & internal medicine ,business ,Demography - Abstract
Background: In January 2015, South Korea’s government raised the cigarette tax, and the retail price of cigarettes abruptly increased by 80% compared to the previous year. This research aimed to determine the effect of this increase on smoking cessation among South Korean smokers. Methods: We analyzed data collected by the 2013-2015 South Korea National Health and Nutrition Examination Survey of 15,203 South Koreans over 19 years old using regression analysis. We examined the recent non-smoking period of nonsmoking people, prepared according to the survey, and analyzed the recent smoking cessation ratio. Results: Among smokers, from 2013 to 2014, the smoking cessation rate was 7.2%, and it increased to 9.9% in 2015 after the increase in the cigarette tax. In 2015, the recent smoking cessation rate was higher among people over the age of 60 (odds ratio [OR], 2.67) compared to those between the ages of 40 and 49. The recent smoking cessation rate was higher among people with below elementary education (OR, 2.28) and above university education (OR, 1.94) compared to high school, higher for those with apartments (OR, 1.74) compared to general type residences, and higher among those with a household income in the low-middle quartile (Q2) (OR, 2.32) compared to the highest quartile (Q4). Conclusion: This innovative policy including increase in cigarette prices affected smoking cessation, and its impact varied by sub-group of smokers in South Korea.
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- 2019
34. Dietary vitamin C intake protects against COPD: the Korea National Health and Nutrition Examination Survey in 2012
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Hyung Jung Kim, Min Kwang Byun, Yu Il Kim, Hye Jung Park, Eun Mi Chun, Jae Yeol Kim, Kwang Ha Yoo, Chul Min Ahn, Ji Ye Jung, and Sang Haak Lee
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Male ,Time Factors ,Health Status ,vitamin C ,Ascorbic Acid ,Pulmonary function testing ,Pulmonary Disease, Chronic Obstructive ,chemistry.chemical_compound ,0302 clinical medicine ,Risk Factors ,Odds Ratio ,Prevalence ,030212 general & internal medicine ,Original Research ,COPD ,Retinol ,General Medicine ,Middle Aged ,Nutrition Surveys ,nutrition ,risk factor ,Female ,Adult ,Vitamin ,medicine.medical_specialty ,National Health and Nutrition Examination Survey ,International Journal of Chronic Obstructive Pulmonary Disease ,Risk Assessment ,smoking ,03 medical and health sciences ,Internal medicine ,Republic of Korea ,medicine ,Humans ,Risk factor ,Aged ,Chi-Square Distribution ,business.industry ,Odds ratio ,Protective Factors ,medicine.disease ,Ascorbic acid ,Diet ,Logistic Models ,030228 respiratory system ,chemistry ,Multivariate Analysis ,Physical therapy ,business ,chronic obstructive lung disease - Abstract
Hye Jung Park,1 Min Kwang Byun,1 Hyung Jung Kim,1 Jae Yeol Kim,2 Yu-Il Kim,3 Kwang-Ha Yoo,4 Eun Mi Chun,5 Ji Ye Jung,6 Sang Haak Lee,7 Chul Min Ahn1 On behalf of the Korean Smoking Cessation Study Group 1Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, 2Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, 3Department of Internal Medicine, Chonnam National University Hospital, Gwangju, 4Department of Internal Medicine, Konkuk University School of Medicine, 5Department of Internal Medicine, Ewha Womans University School of Medicine, 6Division of Pulmonology, Department of Internal Medicine, Institute of Chest Disease, Severance Hospital, Yonsei University College of Medicine, 7Division of Pulmonology, Critical Care and Sleep Medicine, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul,Korea Background: Vitamin C, as an antioxidant, has recently been suggested to provide protection against COPD; however, only few national cohort studies have investigated these effects. We aimed to confirm the protective effects of vitamin C against COPD in Korean patients. Patients and methods: We analyzed the data of 3,283 adults aged ≥40years (representing 23,541,704 subjects) who underwent pulmonary function tests and responded to questionnaires on smoking history and vitamin C intake, with stratification variables and sampling weight designated by the Korea 2012 National Health and Nutrition Examination Survey. Results: Among all the subjects, 512 (representing 3,459,679 subjects; 15.6%) were diagnosed as having COPD based on pulmonary function test results. Male gender, old age, residence in suburban/rural regions, low household income, low educational level, an occupation in agriculture or fisheries, and heavy smoking were significantly associated with COPD. Low intake of nutrients, including potassium, vitamin A, carotene, retinol, and vitamin C, was significantly associated with COPD. The prevalence of COPD in heavy smokers with the lowest quartile (Q1, 141.63mg; 32.6%) of vitamin C intake (P=0.015). In multivariate analysis, male gender, old age, heavy smoking, and a low intake of vitamin C were significant independent risk factors for COPD. A significant reduction of 76.7% in COPD risk was observed with a Q3 vitamin C intake compared to Q1 vitamin C intake (odds ratio, 0.233; 95% confidence interval, 0.094-0.576) in heavy smokers. Conclusion: This large-scale national study suggests that dietary vitamin C provides protection against COPD, independent of smoking history, in the general Korean population. Keywords: chronic obstructive lung disease, vitamin C, nutrition, risk factor, smoking 
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- 2016
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35. Detection of a Radar Signal Using the Periodicity of its Autocorrelation Function
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Hyung-Jung Kim, Chang Joo Kim, and Chang Heon Lim
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Computer science ,Autocorrelation technique ,Pulse-Doppler radar ,Autocorrelation ,020206 networking & telecommunications ,02 engineering and technology ,Signal ,law.invention ,Continuous-wave radar ,Cognitive radio ,law ,0202 electrical engineering, electronic engineering, information engineering ,Radar ,Remote sensing - Published
- 2016
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36. A case of glutathione-induced life-threatening asthma attack
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Jae Kyoung Kim, Jung Hwan Park, Taehee Kim, Hyung Jung Kim, Jae Hwa Cho, Min Kwang Byun, Min-Suck Kang, Do Sun Kwon, and Hye Jung Park
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Mechanical ventilation ,Budesonide ,business.industry ,medicine.medical_treatment ,General Medicine ,medicine.disease ,respiratory tract diseases ,03 medical and health sciences ,0302 clinical medicine ,Epinephrine ,030228 respiratory system ,Anesthesia ,medicine ,Salbutamol ,030212 general & internal medicine ,Salmeterol ,business ,Anaphylaxis ,Montelukast ,medicine.drug ,Asthma - Abstract
Baek-ok injection (glutathione) has been widely used antioxidant therapy to whiten and has antiaging effects in Korea. Glutathione is an enzyme which synthesizes leukotriene, then it can induce asthma attack theoretically; however, there have been few case re ports concerning this therapy. In this report, we described a 41-year-old woman who developed glutathione-induced life-threaten ing asthma attack. She has asthma history controlled by an intermittent salbutamol inhaler. She developed general weakness and dyspnea right after glutathione injection, and injection was discontinued. Dyspnea was progressively aggravated, and she lost con sciousness with shock. Cardiopulmonary resuscitation was started, and she arrived at the Emergency Department with wheezing, hypoxia, severe respiratory acidosis, and nonmeasurable blood pressure. Intubation and mechanical ventilation were started with intramuscular epinephrine/intravenous methylprednisolone injection and repeated salbutamol/ipratropium/budesonide inhala tion. After 5 hours, extubation and spontaneous breathing were successful without wheezing. Next day, pulmonary function test showed moderate an obstructive airway disease pattern, and she was discharged with inhaled fluticasone/salmeterol, oral methyl prednisolone, and montelukast. We can exclude anaphylaxis, because serum tryptase obtained at the Emergency Department was 0.0 mg/dL and the absence of skin lesions and angioedema at arrival. Baek-ok injection (glutathione) should be carefully performed in asthma patients. (Allergy Asthma Respir Dis 2020;8:89-91)
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- 2020
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37. High versus low attenuation thresholds to determine the solid component of ground-glass opacity nodules
- Author
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Kyunghwa Han, Hyung Jung Kim, Geun Dong Lee, Sungsoo Lee, Chul Hwan Park, Jae-Ho Lee, Min Kwang Byun, Yoon Soo Chang, and Tae Hoon Kim
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Male ,Lung Neoplasms ,Focus (geometry) ,lcsh:Medicine ,Pathology and Laboratory Medicine ,Lung and Intrathoracic Tumors ,Ground-glass opacity ,Diagnostic Radiology ,030218 nuclear medicine & medical imaging ,0302 clinical medicine ,Adenocarcinomas ,Medicine and Health Sciences ,lcsh:Science ,Tomography ,Optical Properties ,Multidisciplinary ,Adenocarcinoma of the Lung ,Radiology and Imaging ,Middle Aged ,Predictive value ,Pulmonary Imaging ,Oncology ,030220 oncology & carcinogenesis ,Physical Sciences ,Adenocarcinoma ,Female ,medicine.symptom ,Research Article ,Opacity ,Imaging Techniques ,Materials Science ,Material Properties ,Neuroimaging ,Surgical and Invasive Medical Procedures ,Adenocarcinoma of Lung ,Adenocarcinoma in Situ ,Minimally Invasive Surgery ,Research and Analysis Methods ,Carcinomas ,Sensitivity and Specificity ,Diagnosis, Differential ,03 medical and health sciences ,Signs and Symptoms ,Diagnostic Medicine ,Hounsfield scale ,medicine ,Humans ,Aged ,Retrospective Studies ,business.industry ,Attenuation ,lcsh:R ,Biology and Life Sciences ,Cancers and Neoplasms ,Solitary Pulmonary Nodule ,medicine.disease ,Solid component ,Computed Axial Tomography ,ROC Curve ,Lesions ,lcsh:Q ,Tomography, X-Ray Computed ,Nuclear medicine ,business ,Neuroscience - Abstract
Objectives To evaluate and compare the diagnostic accuracy of high versus low attenuation thresholds for determining the solid component of ground-glass opacity nodules (GGNs) for the differential diagnosis of adenocarcinoma in situ (AIS) from minimally invasive adenocarcinoma (MIA) and invasive adenocarcinoma (IA). Methods Eighty-six pathologically confirmed GGNs < 3 cm observed in 86 patients (27 male, 59 female; mean age, 59.3 ± 11.0 years) between January 2013 and December 2015 were retrospectively included. The solid component of each GGN was defined using two different attenuation thresholds: high (-160 Hounsfield units [HU]) and low (-400 HU). According to the presence or absence of solid portions, each GGN was categorized as a pure GGN or part-solid GGN. Solid components were regarded as indicators of invasive foci, suggesting MIA or IA. Results Among the 86 GGNs, there were 57 cases of IA, 19 of MIA, and 10 of AIS. Using the high attenuation threshold, 44 were categorized as pure GGNs and 42 as part-solid GGNs. Using the low attenuation threshold, 13 were categorized as pure GGNs and 73 as part-solid GGNs. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy for the invasive focus were 55.2%, 100%, 100%, 22.7%, and 60.4%, respectively, for the high attenuation threshold, and 93.4%, 80%, 97.2%, 61.5%, and 91.8%, respectively, for the low attenuation threshold. Conclusion The low attenuation threshold was better than the conventional high attenuation threshold for determining the solid components of GGNs, which indicate invasive foci.
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- 2018
38. Differences of lung microbiome in patients with clinically stable and exacerbated bronchiectasis
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Hyung Jung Kim, Seok Jeong, Joon Chang, and Min Kwang Byun
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Male ,Physiology ,Molecular biology ,Gene Sequencing ,lcsh:Medicine ,medicine.disease_cause ,Pathology and Laboratory Medicine ,Biochemistry ,Polymerase Chain Reaction ,Haemophilus influenzae ,Moraxella catarrhalis ,0302 clinical medicine ,Sequencing techniques ,RNA, Ribosomal, 16S ,Prevotella ,Medicine and Health Sciences ,030212 general & internal medicine ,DNA sequencing ,lcsh:Science ,Lung ,Haemophilus Influenzae ,Multidisciplinary ,biology ,medicine.diagnostic_test ,Ecology ,Microbiota ,Pseudomonas Aeruginosa ,Genomics ,Middle Aged ,Bacterial Pathogens ,Body Fluids ,Bronchiectasis ,Nucleic acids ,Shannon Index ,Ribosomal RNA ,Medical Microbiology ,Female ,medicine.symptom ,Pathogens ,Anatomy ,Simpson Index ,Bronchoalveolar Lavage Fluid ,Research Article ,Adult ,Lung microbiome ,Cell biology ,Cellular structures and organelles ,Ecological Metrics ,Haemophilus ,Microbial Genomics ,Microbiology ,03 medical and health sciences ,Pseudomonas ,medicine ,Genetics ,Humans ,Microbiome ,Non-coding RNA ,Microbial Pathogens ,Aged ,Biology and life sciences ,Bacteria ,business.industry ,Ecology and Environmental Sciences ,lcsh:R ,Organisms ,Sputum ,Species Diversity ,biology.organism_classification ,medicine.disease ,Research and analysis methods ,Mucus ,Bronchoalveolar lavage ,Molecular biology techniques ,030228 respiratory system ,RNA ,lcsh:Q ,business ,Ribosomes - Abstract
Background Molecular-based diagnostic techniques can compensate for the inherent limitations of culture-based microbiology and provide a more comprehensive description of an entire community of bacteria at a particular anatomical site. Using culture-independent DNA-based molecular techniques, the aim of the present study was to characterize, differentiate, and compare the composition of lower airway bacterial microbiome between clinically stable and acutely infected patients with bronchiectasis experiencing exacerbation. Methods Patients with clinically stable bronchiectasis and those experiencing acutely exacerbated bronchiectasis were recruited. All patients underwent bronchoscopy. Paired sputum and bronchoalveolar lavage (BAL) samples were collected for microbiological tests. Molecular analysis was performed for BAL samples using 16S ribosomal RNA (rRNA) gene sequencing. Results The mean age of the 14 recruited patients was 60 years (range 42 to 78 years), and nine (64%) were female. Using quantitative culture and 16S rRNA sequencing, the common organisms identified from 14 BAL samples were Haemophilus influenzae, Pseudomonas aeruginosa and Moraxella catarrhalis, and Prevotella. Molecular techniques revealed Prevotella and Veillonella as potentially pathogenic anaerobic species. 16S rRNA gene sequencing yielded similar relative abundances and distributions of taxa in the stable and exacerbated bronchiectasis groups. Alpha diversity with richness, Simpson’s and Shannon indices, and beta diversity using principal coordinate analysis revealed no significant differences in lung microbiome between patients with clinically stable and exacerbated bronchiectasis. Conclusion Culture-based microbiological and molecular-based techniques did not reveal significant differences in the lung microbiome of patients who were clinically stable and those experiencing exacerbated bronchiectasis. Patient-specific microbial communities were dominated by one or several genera, regardless of clinical status. DNA sequencing could identify potentially pathogenic organisms unable to be identified using microbiological methods.
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- 2017
39. Efficacy of Surgical Treatment for Brain Metastasis in Patients with Non-Small Cell Lung Cancer
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Min Kwang Byun, Chul Hwan Park, Hyung Jung Kim, Yoon Soo Chang, Chang-Ki Hong, Je Beom Hong, Tae Hoon Kim, Chul Min Ahn, and Sang Young Kim
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Adult ,Male ,medicine.medical_specialty ,Lung Neoplasms ,Pulmonology ,Kaplan-Meier Estimate ,Disease-Free Survival ,Quality of life ,Non-small cell lung cancer ,Carcinoma, Non-Small-Cell Lung ,medicine ,Humans ,In patient ,brain metastasis ,neurosurgery ,Lung cancer ,Surgical treatment ,Survival analysis ,Aged ,Demography ,Aged, 80 and over ,business.industry ,Brain Neoplasms ,General Medicine ,Middle Aged ,medicine.disease ,Surgery ,Treatment Outcome ,quality of life ,Original Article ,Female ,Non small cell ,Neurosurgery ,business ,Brain metastasis ,Follow-Up Studies - Abstract
Purpose Patients with non-small cell lung cancer (NSCLC) and simultaneously having brain metastases at the initial diagnosis, presenting symptoms related brain metastasis, survived shorter duration and showed poor quality of life. We analyzed our experiences on surgical treatment of brain metastasis in patients with NSCLC. Materials and methods We performed a single-center, retrospective review of 36 patients with NSCLC and synchronous brain metastases between April 2006 and December 2011. Patients were categorized according to the presence of neurological symptoms and having a brain surgery. As a result, 14 patients did not show neurological symptoms and 22 patients presented neurological symptoms. Symptomatic 22 patients were divided into two groups according to undergoing brain surgery (neurosurgery group; n=11, non-neurosurgery group; n=11). We analyzed overall surgery (OS), intracranial progression-free survival (PFS), and quality of life. Results Survival analysis showed there was no difference between patients with neurosurgery (OS, 12.1 months) and non-neurosurgery (OS, 10.2 months; p=0.550). Likewise for intracranial PFS, there was no significant difference between patients with neurosurgery (PFS, 6.3 months) and non-neurosurgery (PFS, 5.3 months; p=0.666). Reliable neurological one month follow up by the Medical Research Council neurological function evaluation scale were performed in symptomatic 22 patients. The scale improved in eight (73%) patients in the neurosurgery group, but only in three (27%) patients in the non-neurosurgery group (p=0.0495). Conclusion Patients with NSCLC and synchronous brain metastases, presenting neurological symptoms showed no survival benefit from neurosurgical resection, although quality of life was improved due to early control of neurological symptoms.
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- 2014
40. Effects of Adjacent Channel Leakage on an Energy Detection Based Spectrum Sensing
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Chang Heon Lim, Chang Joo Kim, and Hyung Jung Kim
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Physics ,Cognitive radio ,business.industry ,Frequency band ,Electrical engineering ,Adjacent channel ,Fading ,False alarm ,business ,Leakage (electronics) - Abstract
When a primary user transmits over some frequency band assigned to it, most of its transmission power tends to be concentrated in the band but a small portion of it spreads into the adjacent bands. Thus the false alarm probability for the adjacent bands can be higher than expected, even though no primary users are active in the bands. A previous work evaluated the effects of the adjacent channel leakage on the performance of an energy detection based spectrum sensing but it did not take into account the fading phenomenon. In this paper, we analyze the effects of the adjacent channel leakage on an energy detection based spectrum sensing scheme in terms of detection probability and false alarm probability in a fading environment.Key words: Cognitive Radio, Spectrum Sensing, Adjacent Channel Leakage, Energy Detection, Feature Detection iW?@Jjklfm nOop cqrs p )t3su^vw
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- 2014
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41. Whole Blood Interferon-γ Release Assay Is Insufficient for the Diagnosis of Sputum Smear Negative Pulmonary Tuberculosis
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Chul Min Ahn, Hyung Jung Kim, Yoon Soo Chang, Hee Jin Park, and Jung Ar Shin
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Adult ,Male ,medicine.medical_specialty ,Pulmonology ,Interferon gamma release assay ,Tuberculin ,macromolecular substances ,environment and public health ,Interferon γ ,Pulmonary tuberculosis ,Internal medicine ,medicine ,Humans ,Tuberculosis, Pulmonary ,Whole blood ,Aged ,Retrospective Studies ,integumentary system ,business.industry ,interferon-γ release assay ,Sputum ,General Medicine ,Middle Aged ,Confidence interval ,Surgery ,active pulmonary tuberculosis ,Smear negative ,Original Article ,Female ,medicine.symptom ,business ,Interferon-gamma Release Tests ,Sputum smear negative pulmonary tuberculosis - Abstract
PURPOSE We investigated the value of an interferon-γ release assay (IGRA) for the diagnosis of active pulmonary tuberculosis (PTB) among sputum smear negative PTB suspects in an environment with intermediate burden of PTB and high Bacillus Calmette-Guerin (BCG) vaccination rate. MATERIALS AND METHODS We retrospectively reviewed IGRA, medical records, chest PA and CT scan of PTB suspects seen at Gangnam Severance Hospital, Seoul, Korea from Oct. 2007 to Apr. 2013. "Active PTB" was diagnosed when 1) M. tuberculosis culture positive, 2) confirmation by pathologic examination; or 3) clinical findings compatible with TB. RESULTS Of 224 sputum smear negative PTB suspects, 94 were confirmed as having active PTB. There were no statistically significant differences in the diagnostic yield of IGRA between immunocompromised and immunocompetent sputum smear negative PTB suspects. IGRA did show superior sensitivity [81.9%, 95% confidence interval (CI); 74.13-89.70%] in the diagnosis of sputum smear negative PTB when compared with chest high-resolution computed tomography (HRCT), tuberculin skin test (TST), and chest X-ray (p
- Published
- 2014
42. The feasibility of CT lung volume as a surrogate marker of donor-recipient size matching in lung transplantation
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Yoon Soo Chang, Jae Min Shin, Seok Jin Haam, Hyung Jung Kim, Tae Hoon Kim, Chul Hwan Park, Kyunghwa Han, Min Kwang Byun, and Woo Sang Jung
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Male ,medicine.medical_specialty ,Correlation coefficient ,medicine.medical_treatment ,Observational Study ,030218 nuclear medicine & medical imaging ,Pulmonary function testing ,03 medical and health sciences ,0302 clinical medicine ,lung transplantation ,Medicine ,Lung transplantation ,Plethysmograph ,Humans ,Lung volumes ,Lung ,CT lung volume ,predicted total lung capacity ,Aged ,Retrospective Studies ,business.industry ,Surrogate endpoint ,Total Lung Capacity ,Retrospective cohort study ,General Medicine ,Organ Size ,respiratory system ,Middle Aged ,Tissue Donors ,respiratory tract diseases ,Respiratory Function Tests ,medicine.anatomical_structure ,030228 respiratory system ,Feasibility Studies ,Female ,Radiology ,business ,Nuclear medicine ,Tomography, X-Ray Computed ,size matching ,Research Article - Abstract
Donor–recipient size matching in lung transplantation (LTx) by computed tomography lung volume (CTvol) may be a reasonable approach because size matching is an anatomical issue. The purpose of this study is to evaluate the feasibility of CTvol as a surrogate marker of size matching in LTx by comparing CTvol and predicted total lung capacity (pTLC) to reference total lung capacity (TLC) values. From January to December 2014, data from 400 patients who underwent plethysmography, pulmonary function testing (PFT), and chest computed tomography scans were reviewed retrospectively. Enrolled 264 patients were divided into 3 groups according to PFT results: Group I, obstructive pattern; Group II, restrictive pattern; Group III, normal range. The correlations between pTLC and TLC and between CTvol and TLC were analyzed, and the linear correlation coefficients were compared. The percentage error rates of pTLC and CTvol were calculated and absolute error rates were compared. The correlation coefficient between CTvol and TLC in Group I was larger than that of pTLC and TLC (0.701 vs 0.432, P = 0.002). The absolute percentage error rate between CTvol and pTLC was lower than that of pTLC in Group II (15.3% ± 11.9% vs 42.2% ± 28.1%, P
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- 2016
43. Design and compensation of second-order sub-sampling digital frontend
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Jin-Up Kim, Jong-seog Koh, Hongmei Wang, Sanghyuk Lee, Jae-Hyung Kim, and Hyung-Jung Kim
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Engineering ,business.industry ,Metals and Alloys ,General Engineering ,Compensation methods ,Software-defined radio ,Interference (wave propagation) ,Sub-sampling ,Compensation (engineering) ,Cognitive radio ,Undersampling ,Electronic engineering ,Radio frequency ,business - Abstract
The problem of designing a digital frontend (DFE) was considered which can dynamically access or sense dual bands in any radio frequency (RF) regions without requiring hardware changes. In particular, second-order bandpass sampling (BPS) as a technique that enables to realize the multiband reception function was discussed. In a second-order BPS system, digital reconstruction filters were utilized to eliminate the interferences generated while down converting arbitrarily positioned RF-band signals by using the direct digitization method. However, the inaccuracy in the phase shift or the amplitude mismatch between the two sample streams may cause insufficient rejection of interference. Practical problems were studied, such as performance degradation in signal-to-interference ratio (SIR) and compensation methods to overcome them. In order to demonstrate the second-order BPS as a flexible DFE suitable for software-defined radio (SDR) or cognitive radio (CR), a DFE testbed with a reconfigurable structure was implemented. Moreover, with a view to further demonstrate the proposed compensation algorithms, experimental results show that dual bands are received simultaneously.
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- 2012
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44. Complex Bandpass Sampling for SDR front-end
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Hongmei Wang, Jae-Hyung Kim, and Hyung-Jung Kim
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General Computer Science ,Finite impulse response ,Computer science ,business.industry ,Sampling (statistics) ,Software-defined radio ,Sampling (signal processing) ,Undersampling ,Nyquist stability criterion ,Electronic engineering ,Nyquist–Shannon sampling theorem ,Telecommunications ,business ,Digital signal processing - Abstract
Bandpass sampling technique has an advantage that it uses lower sampling frequency than Nyquist criterion. But special care is required in choosing sampling frequency to avoid self-image overlapping in the first Nyquist region. Recently, the second-order BPS techniques which can suppress possible self-image by using an additional ADC and by employing digital signal processing have been proposed. This paper addresses a complex BPS based SDR front-end. Unlike general second-order BPS, it needs simple FIR filter to compensate delay in the second ADC. We show a method to find proper sampling frequencies to down convert RF signals selected by tunable RF filter operating in arbitrary frequency range.
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- 2011
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45. A Study on the Implementation of Wideband Hybrid Quadrature Polar Transmitter Platform
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Il-Kyoo Lee, Sang-Ki Kang, Sang-Hyun Chang, and Hyung-Jung Kim
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Attenuator (electronics) ,Engineering ,business.industry ,Electrical engineering ,Electronic engineering ,Wideband ,business ,Polar transmitter ,Voltage - Abstract
In this paper, we proposed the architecture of the Hybrid Quadrature Polar transmitter which has the wideband characteristics available for the SRD(Short Range Device). First, we developed the simulation environment and carried out performance degradation analysis. Second, we considered the slewrate of the VVA(Voltage Variable Attenuator), time delay between magnitude signal and phase signal and the number of bits for DAC(Digital-to-Analog Converter) as the main performance factors. Then we obtained the minimum required values to meet the transmitting performance requirements of 3GPP standards through simulation results. Based on these results, we implemented the Wideband Hybrid Quadrature Polar transmitter platform and varified the performance requirements through practical measurement.
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- 2011
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46. The Design Method and Performance Analysis of RF Subsampling Frontend for SDR/CR Receivers
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Jin-Up Kim, Jae-Hyung Kim, Hyung-Jung Kim, In-Sung Lee, and Hongmei Wang
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Engineering ,business.industry ,Analog-to-digital converter ,Software-defined radio ,law.invention ,Noise ,Signal-to-noise ratio ,Control and Systems Engineering ,law ,Electronic engineering ,Radio frequency ,Electrical and Electronic Engineering ,Antenna (radio) ,business ,Degradation (telecommunications) ,Jitter - Abstract
RF subsampling can be used by radio receivers to directly down convert and digitize RF signals. The goal of software-defined radio (SDR) design is to place analog-to-digital converter (ADC) as near the antenna as possible. Based on this, an RF subsampling frontend (FE) for SDR is designed and verified by a hardware platform. The effects of timing jitter, ADC resolution, and folding noise dominating SNR degradation sources in the digital FE were considered. We present an efficient method of SNR measurement and an analysis of its performance. The experimental results indicate that the three degradation sources are sufficient to estimate the performance of the RF subsampling FE, and this conclusion matches the theoretical analysis results.
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- 2010
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47. RF Band-Pass Sampling Frontend for Multiband Access CR/SDR Receiver
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Jin-Up Kim, Hongmei Wang, Hyung-Jung Kim, Jae-Hyung Kim, and In-Sung Lee
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Engineering ,Signal processing ,General Computer Science ,business.industry ,Frequency band ,Reconstruction filter ,Electronic, Optical and Magnetic Materials ,Cognitive radio ,Band-pass filter ,Sampling (signal processing) ,Electronic engineering ,Radio frequency ,Electrical and Electronic Engineering ,Antenna (radio) ,business - Abstract
Radio frequency (RF) subsampling can be used by radio receivers to directly down-convert and digitize RF signals. A goal of a cognitive radio/software defined ratio (CR/SDR) receiver design is to place the analog-to-digital converter (ADC) as near the antenna as possible. Based on this, a band-pass sampling (BPS) frontend for CR/SDR is proposed and verified. We present a receiver architecture based second-order BPS and signal processing techniques for a digital RF frontend. This paper is focused on the benefits of the second-order BPS architecture in spectrum sensing over a wide frequency band range and in multiband receiving without modification of the RF hardware. Methods to manipulate the spectra are described, and reconstruction filter designs are provided. On the basis of this concept, second-order BPS frontends for CR/SDR systems are designed and verified using a hardware platform.
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- 2010
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48. Clinical significance of insulin-like growth factor-1 receptor expression in stage I non-small-cell lung cancer: immunohistochemical analysis
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Chang Youl Lee, Jeong Hee Jeon, Hyung Jung Kim, Yoon Soo Chang, Tae Woong Roh, Chul Min Ahn, and Dong Hwan Shin
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Adult ,Male ,Pathology ,medicine.medical_specialty ,medicine.medical_treatment ,Receptor expression ,NSCLC ,Metastasis ,Receptor, IGF Type 1 ,Insulin-like growth factor ,Mice ,Carcinoma, Non-Small-Cell Lung ,medicine ,Animals ,Humans ,Clinical significance ,IGF ,Insulin-Like Growth Factor I ,Neoplasm Metastasis ,Lung cancer ,Aged ,Neoplasm Staging ,Aged, 80 and over ,business.industry ,Growth factor ,General Medicine ,Middle Aged ,medicine.disease ,Prognosis ,Immunohistochemistry ,Cancer cell ,Original Article ,Female ,business ,IGF-1R - Abstract
Background/Aims: The insulin-like growth factor (IGF) system has been implicated in tumor growth, invasion, and metastasis. However, reports on the IGF-1 receptor (IGF-1R) based on radioimmunoassays are conflicting, and its prognostic implications in non-small-cell lung cancer (NSCLC) are still controversial. Methods: Seventy-one paraffin-embedded tissue sections from stage I NSCLC patients were stained using a mouse monoclonal antibody against human IGF-1R. Results: The intensity and frequency of IGF-1R expression on the membrane and cytoplasm of cancer cells was evaluated and scored using a semiquantitative system. IGF-1R expression was detected in nine of 71 (12.7%) cases. No significant relationship was found between clinical/histopathological parameters and IGF-1R expression. None of the patients whose tumor expressed IGF-1R had experienced distant metastasis or cancer-related death, although the difference did not reach statistical significance. Conclusions: We conclude that IGF-1R expression may not be a major prognostic factor for stage I NSCLC.
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- 2008
49. Performance Analysis of MIMO-OFDM System Applying AMC and SFC Schemes
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Yun-Ho Lee, Hyung-Jung Kim, Kyung-Seok Kim, and Gweon-Do Jo
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Block code ,Orthogonal frequency-division multiplexing ,Computer science ,ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS ,Telecommunications link ,Electronic engineering ,Link adaptation ,Data_CODINGANDINFORMATIONTHEORY ,Wideband ,MIMO-OFDM ,Multipath propagation ,Coding (social sciences) - Abstract
Adaptive modulation and Coding(AMC) scheme is promising technique to support the demands for high data rates and wideband proposed for 4G mobile communication system standards. In this paper, adaptive modulation and coding(AMC) based on OFDM system is analyzed through simulation for single user case and compared with SISO-OFDM and SFBC(Space frequency block coding)-OFDM. The performance analysis in terms of capacity for downlink system environments with different values of constellation size under multipath fading channel is done. The adaptive modulation and coding technique is based on perfect estimation channel. It has been observed that SFBC(Space-frequency block coding)-OFDM system gives better performance in terms of capacity.
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- 2008
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50. Efficient Scheduling Method based Cross-Layer on Mobile Communication Multimedia Environments
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Hyung-Jung Kim, Kyung-Seok Kim, Joo-Seok Kim, and Gweon-Do Jo
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Rate-monotonic scheduling ,Multimedia ,Computer science ,business.industry ,Distributed computing ,Dynamic priority scheduling ,Round-robin scheduling ,computer.software_genre ,Fair-share scheduling ,Scheduling (computing) ,Fixed-priority pre-emptive scheduling ,Genetic algorithm scheduling ,Two-level scheduling ,business ,computer ,Computer network - Abstract
Allocation and management of the resource is very important in wireless networks because the wireless resource is limited. Therefore, the importance of designing cross layer, which adapt between different layers, is on the rise. In this paper, we investigate the scheduling techniques of the cross layer. This paper researches conventional scheduling methods and proposes the complementary scheduling method. On multimedia environment, the scheduling method must be applied variably because of offering variable services. Therefore, this paper proposes the new scheduling method according to the variable services. The proposed method shows that utility efficiency of the wireless resource more excellent than the conventional method through the simulations.
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- 2007
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