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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.

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

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.

The garment industry, which is traditionally labour-intensive, is facing significant challenges to reduce production costs in the face of material, labour, and infrastructure maintenance cost incre...

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.

Analyses of sea spikes are presented for data measured at low grazing angles using a high-resolution X-band radar. To investigate the spikiness of sea clutter at different range resolutions...

Artificial muscle is one of the more prominent topics in modern robotics as it can be applied to robotic arms, electric vehicles and wearable robots (Shahinpoor et al. in Smart Mater Struct 7:15–30, 1998; Jani et al. in Mater Des 56:1078–1113, 2014). The advantages of Shape Memory Alloy (SMA) artificial muscle are lightness and high energy density. The high energy density allows the actuator to make powerful motions. Meanwhile, SMA wire contracts 6% of its length, which means that the required displacement cannot be achieved by a simple connection. To resolve these disadvantages, the SMA wires are coiled in a diamond-shaped structure. If the electric current is given by contracting wires in the longitudinal direction, the actuator can exert force and displacement in the diagonal direction. As the crossed tendon finds its minimal length when actuated, the rotation angle converges to 90°. Parameters related with the rotating motion were selected, such as SMA wires’ diameter and length, distance between the crossed part and elbow part, size of the diamond-shaped structure, friction, etc. To determine the maximum force of the actuator, a graphical method was used, which is similar to the yield strength determination (0.2% offset). Because the robotic elbow joint is connected by the tendon, the connections between links are flexible, and without motor it does not generate any sound or noise during operation. The robotic elbow joint using the SMA actuator is designed and analyzed, which can rotate 86.7° and generates maximum 56.3 N force.

To enable Small and Medium-sized Enterprises (SMEs) level garment manufacturers to measure and monitor the work of individual workers without incurring a large financial burden, a smart sewing work...

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].

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.

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.

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)

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)

In Spectrum-Shared Networked Radar (SSNR), multiple radars share the same frequency band for transmitting their own waveforms and receiving echo signals. In SSNR, an echo signal originated from one radar can be distorted by the signals from the other radars. To address this issue, several researchers have proposed to incorporate an orthogonal polyphase code into a pulse-compressed waveform. Even though there are several system parameters in creating an orthogonal code set, previous works have not investigated the impact of the parameters on the performance of SSNR thoroughly. Moreover, the previous works have not considered factors affecting the performance of SSNR at receiver side including noise and wireless channel. In this paper, we perform an in-depth simulation study of orthogonal polyphase codes used in SSNR to reveal the impact of the system parameters on the performance of SSNR. Based on the simulation findings, we suggest guidelines to generate an orthogonal code set for improving SSNR.

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.

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

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.

The Fourth Industrial Revolution incorporates the digital revolution into the physical world, creating a new direction in a number of fields, including artificial intelligence, quantum computing, nanotechnology, biotechnology, robotics, 3D printing, autonomous vehicles, and the Internet of Things. The artificial intelligence field has encountered a turning point mainly due to advancements in machine learning, which allows machines to learn, improve, and perform a specific task through data without being explicitly programmed. Machine learning can be utilized with machining processes to improve product quality levels and productivity rates, to monitor the health of systems, and to optimize design and process parameters. This is known as smart machining, referring to a new machining paradigm in which machine tools are fully connected through a cyber-physical system. This paper reviews and summarizes machining processes using machine learning algorithms and suggests a perspective on the machining industry.

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

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

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.

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.

Background and objective Although an association between pulmonary tuberculosis (TB) and chronic obstructive pulmonary disease (COPD) has been suggested, studies on the effect of TB in COPD patients have not been conducted. We aimed to investigate the severity and clinical outcomes of COPD in patients with and without a history of TB. Methods We retrospectively reviewed the data of 1784 patients with COPD in the Korean COPD Subtype Study cohort collected from December 2011 to January 2017 and followed up for 3 years. Results Among the 1784 patients at baseline, the COPD assessment test (CAT) scores and total St George's Respiratory Questionnaire for COPD (SGRQc) scores were significantly higher in the prior TB group (n = 468) than in the non-TB group (n = 1316). Lung function and exacerbation prevalence were significantly poorer and higher, respectively, in the prior TB group than in the non-TB group. In a small-sized follow-up study, CAT scores (n = 318), SGRQc scores (n = 295) and lung function (n = 182) remained poorer, and exacerbation prevalence (n = 256) remained higher in the prior TB group over 3 years. The forced expiratory volume in 1 s in the prior TB group declined (−0.57%/year), whereas it improved (+0.93%/year) in the non-TB group (P for changes between the groups = 0.076). In the prior TB group, patients showed poorer lung function compared with the non-TB group regardless of having lung lesions visible or not on chest radiographs. Conclusion TB history negatively affected the severity of COPD, and a small-sized follow-up study showed that the changes were sustained for several years.