43 results on '"Hyeon-Woo Park"'
Search Results
2. Estimating Fluor Emission Spectra Using Digital Image Analysis Compared to Spectrophotometer Measurements
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Hyeon-Woo Park, Ji-Won Choi, Kyung-Kwang Joo, Na-Ri Kim, and Chang-Dong Shin
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liquid scintillator ,color space ,digital camera ,image analysis ,spectrophotometer ,fluor ,Chemical technology ,TP1-1185 - Abstract
This paper describes a practical method for obtaining the spectra of lights emitted by a fluor in a liquid scintillator (LS) using a digital camera. The emission wavelength results obtained using a digital image were compared with those obtained using a fluorescence spectrophotometer. For general users, conventional spectrophotometers are expensive and difficult to access. Moreover, their experimental measurement setup and processes are highly complicated, and they require considerable care in handling. To overcome these limitations, a feasibility study was performed to obtain the emission spectrum through image analysis. Specifically, the emission spectrum of a fluor dissolved in a liquid scintillator was obtained using digital image analysis. An image processing method was employed to convert the light irradiated during camera exposure into wavelengths. Hue (H) and wavelength (W) are closely related. Thus, we obtained an H-W response curve in the 400~450 nm wavelength region, using a light-emitting diode. Another relevant advantage of the method described in this study is its non-invasiveness in sealed LS samples. Our results showed that this method has the potential to accurately investigate the emission wavelengths of fluor within acceptable uncertainties. We envision the use of this method to perform experiments in chemistry and physics laboratories in the future.
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- 2023
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3. Investigation of the Hue–Wavelength Response of a CMOS RGB-Based Image Sensor
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Hyeon-Woo Park, Ji-Won Choi, Ji-Young Choi, Kyung-Kwang Joo, and Na-Ri Kim
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color space ,H-W curve ,digital camera ,CMOS sensor ,Chemical technology ,TP1-1185 - Abstract
In this study, a non-linear hue–wavelength (H-W) curve was investigated from 400 to 650 nm. To date, no study has reported on H-W relationship measurements, especially down to the 400 nm region. A digital camera mounted with complementary metal oxide semiconductor (CMOS) image sensors was used. The obtained digital images of the sample were based on an RGB-based imaging analysis rather than multispectral imaging or hyperspectral imaging. In this study, we focused on the raw image to reconstruct the H-W curve. In addition, several factors affecting the digital image, such as exposure time or international organization for standardization (ISO), were investigated. In addition, cross check of the H-W response using laser was performed. We expect that our method will be useful as an auxiliary method in the future for obtaining the fluor emission wavelength information.
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- 2022
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4. The Spectrum of Light Emitted by LED Using a CMOS Sensor-Based Digital Camera and Its Application
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Hyeon-Woo Park, Ji-Won Choi, Ji-Young Choi, Kyung-Kwang Joo, and Na-Ri Kim
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color space ,hue and wavelength curve ,complementary metal oxide semiconductor sensor ,Bayer color filter array ,digital camera ,Chemical technology ,TP1-1185 - Abstract
We introduced a digital photo image analysis in color space to estimate the spectrum of fluor components dissolved in a liquid scintillator sample through the hue and wavelength relationship. Complementary metal oxide semiconductor (CMOS) image sensors with Bayer color filter array (CFA) technology in the digital camera were used to reconstruct and decode color images. Hue and wavelength are closely related. To date, no literature has reported the hue and wavelength relationship measurements, especially for blue or close to the UV region. The non-linear hue and wavelength relationship in the blue region was investigated using a light emitting diode source. We focused on this wavelength region, because the maximum quantum efficiency of the bi-alkali photomultiplier tube (PMT) is around 430 nm. It is necessary to have a good understanding of this wavelength region in PMT-based experiments. The CMOS Bayer CFA approach was sufficient to estimate the fluor emission spectrum in the liquid scintillator sample without using an expensive spectrophotometer.
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- 2022
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5. Genetic Polymorphisms in the 3′-Untranslated Regions of SMAD5, FN3KRP, and RUNX-1 Are Associated with Recurrent Pregnancy Loss
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Min-Jung Kwon, Ji-Hyang Kim, Jeong-Yong Lee, Eun-Ju Ko, Hyeon-Woo Park, Ji-Eun Shin, Eun-Hee Ahn, and Nam-Keun Kim
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SMAD5 ,FN3KRP ,RUNX-1 ,polymorphism ,recurrent pregnancy loss ,Biology (General) ,QH301-705.5 - Abstract
Recurrent pregnancy loss (RPL) is typically defined as two or more consecutive pregnancy losses prior to 20 weeks of gestation. Although the causes of idiopathic RPL are not completely understood, vascular development and glucose concentration were reported to correlate with the pregnancy loss. The TGF-β signaling pathway which plays a significant role in pregnancy is activated by the interaction between high glucose and SMAD signaling and affects the vascular cells. SMAD5 and RUNX-1 are involved in the TGF-β signaling pathway and contribute to advanced glycation end products (AGEs) production and vascular development. FN3KRP, a newly described gene, is also associated with vascular diseases and suggested to relate to AGEs. Therefore, in the present study, we investigated associations between RPL risk and genetic polymorphisms of SMAD5, FN3KRP, and RUNX-1 in 388 women with RPL and 280 healthy control women of Korean ethnicity. Participants were genotyped using real-time polymerase chain reaction and restriction fragment length polymorphism assay to determine the frequency of SMAD5 rs10515478 C>G, FN3KRP rs1046875 G>A, and RUNX-1 rs15285 G>A polymorphisms. We found that women with RPL had lower likelihoods of the FN3KRP rs1046875 AA genotype (adjusted odds ratio (AOR), 0.553; p = 0.010) and recessive model (AOR, 0.631; p = 0.017). Furthermore, combination analysis showed that SMAD5 rs10515478 C>G and FN3KRP rs1046875 G>A mutant alleles were together associated with reduced RPL risk. These findings suggest that the FN3KRP rs1046875 G>A polymorphism has a significant role on the prevalence of RPL in Korean women. Considering that it is the first study indicating a significant association between FN3KRP and pregnancy disease, RPL, our results suggest the need for further investigation of the role of FN3KRP in pregnancy loss.
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- 2022
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6. Reversible transition between the polar and antipolar phases and its implications for wake-up and fatigue in HfO2-based ferroelectric thin film
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Yan Cheng, Zhaomeng Gao, Kun Hee Ye, Hyeon Woo Park, Yonghui Zheng, Yunzhe Zheng, Jianfeng Gao, Min Hyuk Park, Jung-Hae Choi, Kan-Hao Xue, Cheol Seong Hwang, and Hangbing Lyu
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Science - Abstract
HfO2-based ferroelectric films are attracting a great deal of attention. Here, the authors conclude that the performance degradation and the possible rejuvenation are ascribed to the reversible transition between polar and antipolar phases.
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- 2022
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7. A Comparative Study on the Ferroelectric Performances in Atomic Layer Deposited Hf0.5Zr0.5O2 Thin Films Using Tetrakis(ethylmethylamino) and Tetrakis(dimethylamino) Precursors
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Baek Su Kim, Seung Dam Hyun, Taehwan Moon, Keum Do Kim, Young Hwan Lee, Hyeon Woo Park, Yong Bin Lee, Jangho Roh, Beom Yong Kim, Ho Hyun Kim, Min Hyuk Park, and Cheol Seong Hwang
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Ferroelectric Hf0.5Zr0.5O2 film ,Atomic layer deposition ,Metal-organic precursor ,Wake-up phenomenon ,Interfacial layer ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
Abstract The chemical, physical, and electrical properties of the atomic layer deposited Hf0.5Zr0.5O2 thin films using tetrakis(ethylmethylamino) (TEMA) and tetrakis(dimethylamino) (TDMA) precursors are compared. The ligand of the metal-organic precursors strongly affects the residual C concentration, grain size, and the resulting ferroelectric properties. Depositing Hf0.5Zr0.5O2 films with the TDMA precursors results in lower C concentration and slightly larger grain size. These findings are beneficial to grow more ferroelectric-phase-dominant film, which mitigates its wake-up effect. From the wake-up test of the TDMA-Hf0.5Zr0.5O2 film with a 2.8 MV/cm cycling field, the adverse wake-up effect was well suppressed up to 105 cycles, with a reasonably high double remanent polarization value of ~40 μC/cm2. The film also showed reliable switching up to 109 cycles with the 2.5 MV/cm cycling field without involving the wake-up effect but with the typical fatigue behavior.
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- 2020
- Full Text
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8. Flow Curve of Superalloy 718 under Hot Forming in a Region of γ' Precipitation
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Hyung-Won Park, Kyunghyun Kim, Hyeon-Woo Park, Akira Yanagida, and Jun Yanagimoto
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Mechanics of Materials ,Mechanical Engineering ,Materials Chemistry ,Metals and Alloys - Published
- 2023
9. Effect of drying and grinding characteristics of colored potato (Solanum tuberosum L.) on tribology of mashed colored potato paste
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Hyeon Woo Park and Won Byong Yoon
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Colored potato ,mashed potato ,drying ,anthocyanins ,grinding ,tribology ,rheology ,Nutrition. Foods and food supply ,TX341-641 ,Food processing and manufacture ,TP368-456 - Abstract
The mouthfeel of mashed potato prepared with steamed purple flesh potato (SPFP) was investigated by measuring tribological and rheological characteristics. Mathematical models describing pre-processes such as drying and grinding associated with physical properties of mashed potato were also explored. The effect of drying temperature (60, 70, 80, and 90°C) on quality changes (moisture and anthocyanin content) of SPFP was successfully described (R2 > 0.9583). The sigmoid model was suitably applied to estimate particle sizes of dried SPFP during grinding (R2 > 0.9864). As the particle size of mashed SPFP increased, friction coefficient increased, and storage and loss modulus decreased. Taste, smoothness, and after-feel sensation were increased as particle sizes decreased, while appearance and odor showed no significant differences. To predict the sensory property using tribology and rheology, the specific conditions were successfully determined (R2 > 0.9926).
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- 2018
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10. Evolution of the Ferroelectric Properties of AlScN Film by Electrical Cycling with an Inhomogeneous Field Distribution
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Kyung Do Kim, Yong Bin Lee, Suk Hyun Lee, In Soo Lee, Seung Kyu Ryoo, Seungyong Byun, Jae Hoon Lee, Hani Kim, Hyeon Woo Park, and Cheol Seong Hwang
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Electronic, Optical and Magnetic Materials - Published
- 2023
11. Formulation of a Generalized Flow Curve for 0.2% Carbon Steel under High-speed Hot Forming Conditions by a Regression Method
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Jun Yanagimoto, Sheng Ding, Hyeon-Woo Park, Hyung-Won Park, and Kyunghyun Kim
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High strain rate ,Flow curve ,Materials science ,Carbon steel ,Mechanical Engineering ,Extrapolation ,Metals and Alloys ,Mechanics ,engineering.material ,Condensed Matter Physics ,Regression ,Mechanics of Materials ,Heat generation ,engineering ,Materials Chemistry ,Physical and Theoretical Chemistry - Published
- 2022
12. Association of Polymorphisms in the Long Non-Coding RNA
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Hyeon Woo, Park, Young Ran, Kim, Jeong Yong, Lee, Eun Ju, Ko, Min Jung, Kwon, Ji Hyang, Kim, and Nam Keun, Kim
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Abortion, Habitual ,Asian People ,Pregnancy ,Republic of Korea ,Humans ,Female ,Genetic Predisposition to Disease ,RNA, Long Noncoding - Abstract
Recurrent pregnancy loss (RPL) affects 1% to 5% of women, with devastating effects on both reproductive health and psychological well-being. Homeobox (
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- 2022
13. Review of ferroelectric field‐effect transistors for three‐dimensional storage applications
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Cheol Seong Hwang, Hyeon Woo Park, and Jae-Gil Lee
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Materials science ,Hardware_MEMORYSTRUCTURES ,business.industry ,interference ,domain pattern ,Depolarization ,NAND architecture ,Ferroelectricity ,ferroelectric field‐effect transistor ,depolarization ,Interference (communication) ,Hardware_GENERAL ,TA401-492 ,Optoelectronics ,Field-effect transistor ,business ,Materials of engineering and construction. Mechanics of materials - Abstract
The ferroelectric field‐effect transistor (FeFET) is one of the leading contenders to succeed charge‐trap‐based flash memory (CTF) devices in the current vertically‐integrated NAND flash storage market. The operation of a FeFET is based on the field‐effect in the channel of the FET that is exerted by the uncompensated ferroelectric bound charge, which is also the fundamental source of the depolarization effect. This paper briefly reviews the current status of CTF‐based NAND flash memory as a benchmark for FeFET. Then, a one‐dimensional model based on a load‐line analysis of FeFET technology is presented. The paper subsequently deals with the two‐dimensional domain effect in nano‐sized NAND‐type FeFET devices. While NAND‐type FeFET operation is likely, current ferroelectric materials with high remanent polarization (Pr) of ∼10 μCcm‐2 and coercive field (Ec) of ∼1 MVcm‐1 are not feasible for use in such devices. This is fundamentally due to the high depolarization field induced by the unnecessarily high Pr, which not only destabilizes the memory state but also induces a severe interference effect between neighboring cells. Therefore, a new ferroelectric material with a moderately low Pr and higher Ec > ∼3 MVcm‐1 is necessary, along with structural innovation to minimize the interference effect.
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- 2021
14. Flow Stress of Duplex Stainless Steel by Inverse Analysis with Dynamic Recovery and Recrystallization Model
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Jun Yanagimoto, Sheng Ding, Hyeon-Woo Park, Kyunghyun Kim, and Hyung-Won Park
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Materials science ,Mechanics of Materials ,Duplex (building) ,Mechanical Engineering ,Materials Chemistry ,Metals and Alloys ,Dynamic recrystallization ,Recrystallization (metallurgy) ,Composite material ,Flow stress ,Inverse analysis - Published
- 2021
15. Study of the Association between VEGF Polymorphisms and the Risk of Coronary Artery Disease in Koreans
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Eun-Ju Ko, In-Jai Kim, Jeong-Yong Lee, Hyeon-Woo Park, Han-Sung Park, Sang-Hoon Kim, Jae-Youn Moon, Jung-Hoon Sung, and Nam-Keun Kim
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coronary artery disease ,VEGF ,promoter region ,3′-untranslated region ,endothelial homeostasis ,angiogenesis ,Medicine (miscellaneous) - Abstract
Coronary artery disease (CAD), a leading cause of death worldwide, has a complex etiology comprising both traditional risk factors (type 2 diabetes, dyslipidemia, arterial hypertension, and cigarette smoking) and genetic factors. Vascular endothelial growth factor (VEGF) notably contributes to angiogenesis and endothelial homeostasis. However, little is known about the relationship between CAD and VEGF polymorphisms in Koreans. The aim of this study is to investigate the associations of 2 VEGF promoter region polymorphisms (−1154G>A [rs1570360], −1498T>C [rs833061]) and 4 VEGF 3′-UTR polymorphisms (+936C>T [rs3025039], +1451C>T [rs3025040], +1612G>A [rs10434], and +1725G>A [rs3025053]) with CAD susceptibility in Koreans. We studied 885 subjects: 463 CAD patients and 422 controls. Genotyping was conducted with polymerase chain reaction-restriction fragment length polymorphism analysis and TaqMan allelic discrimination assays, and the genotype frequencies were calculated. We then performed haplotype and genotype combination analyses and measured the associations between VEGF polymorphisms and clinical variables in both the CAD patients and control subjects. We detected statistically significant associations between CAD and certain VEGF allele combinations. In the haplotypes of 5 single-nucleotide polymorphisms, the VEGF allele combination −1154A/+936T was associated with a decreased prevalence of CAD (A-T-T-G-G of VEGF −1154G>A/−1498T>C/+936C>T/+1612G>A/+1725G>A, AOR = 0.077, p = 0.021). In contrast, the VEGF allele combinations −1498T/+1725A and −1498T/+1612A/+1725A were associated with an increased prevalence of CAD (G-T-C-C-A of VEGF −1154G>A/−1498T>C/+936C>T/+1451C>T/+1725G>A, AOR = 1.602, p = 0.047; T-C-C-A-A of VEGF −1498T>C/+936C>T/+1451C>T/+1612G>A/+1725G>A, AOR = 1.582, p = 0.045). Gene–environment combinatorial analysis showed that the combination of the VEGF +1725AA genotype and several clinical factors (e.g., body mass index, hemoglobin A1c, and low-density lipoprotein cholesterol) increased the risk of CAD. Therefore, we suggest that VEGF polymorphisms and clinical factors may impact CAD prevalence.
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- 2022
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16. A Comparative Study on the Ferroelectric Performances in Atomic Layer Deposited Hf0.5Zr0.5O2 Thin Films Using Tetrakis(ethylmethylamino) and Tetrakis(dimethylamino) Precursors
- Author
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Seung Dam Hyun, Taehwan Moon, Yong Bin Lee, Baek Su Kim, Ho Hyun Kim, Beom Yong Kim, Hyeon Woo Park, Min Hyuk Park, Cheol Seong Hwang, Keum Do Kim, Young Hwan Lee, and Jangho Roh
- Subjects
Wake-up phenomenon ,Materials science ,Ligand ,Atomic layer deposition ,Analytical chemistry ,Metal-organic precursor ,Nanochemistry ,Ferroelectric Hf0.5Zr0.5O2 film ,Condensed Matter Physics ,Ferroelectricity ,Grain size ,lcsh:TA401-492 ,Interfacial layer ,General Materials Science ,lcsh:Materials of engineering and construction. Mechanics of materials ,Thin film ,Polarization (electrochemistry) ,Layer (electronics) - Abstract
The chemical, physical, and electrical properties of the atomic layer deposited Hf0.5Zr0.5O2 thin films using tetrakis(ethylmethylamino) (TEMA) and tetrakis(dimethylamino) (TDMA) precursors are compared. The ligand of the metal-organic precursors strongly affects the residual C concentration, grain size, and the resulting ferroelectric properties. Depositing Hf0.5Zr0.5O2 films with the TDMA precursors results in lower C concentration and slightly larger grain size. These findings are beneficial to grow more ferroelectric-phase-dominant film, which mitigates its wake-up effect. From the wake-up test of the TDMA-Hf0.5Zr0.5O2 film with a 2.8 MV/cm cycling field, the adverse wake-up effect was well suppressed up to 105 cycles, with a reasonably high double remanent polarization value of ~40 μC/cm2. The film also showed reliable switching up to 109 cycles with the 2.5 MV/cm cycling field without involving the wake-up effect but with the typical fatigue behavior.
- Published
- 2020
17. Flow Stress Measurement and Dynamic Response Analysis of Hot Compression Test Machine at High Strain Rates
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Jun Yanagimoto, Hyung-Won Park, Kyunghyun Kim, and Hyeon-Woo Park
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High strain rate ,Materials science ,business.industry ,Mechanical Engineering ,Response analysis ,Metals and Alloys ,Structural engineering ,Flow stress ,High strain ,Mechanics of Materials ,Materials Chemistry ,Compression test ,business ,Inverse analysis - Published
- 2020
18. Reversible transition between the polar and antipolar phases and its implications for wake-up and fatigue in HfO
- Author
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Yan, Cheng, Zhaomeng, Gao, Kun Hee, Ye, Hyeon Woo, Park, Yonghui, Zheng, Yunzhe, Zheng, Jianfeng, Gao, Min Hyuk, Park, Jung-Hae, Choi, Kan-Hao, Xue, Cheol Seong, Hwang, and Hangbing, Lyu
- Abstract
Atomic-resolution Cs-corrected scanning transmission electron microscopy revealed local shifting of two oxygen positions (O
- Published
- 2021
19. Association of Polymorphisms in Plasminogen Activator Inhibitor-1 (
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Hee Young, Cho, Han Sung, Park, Eun Hee, Ahn, Eun Ju, Ko, Hyeon Woo, Park, Young Ran, Kim, Ji Hyang, Kim, Woo Sik, Lee, and Nam Keun, Kim
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tissue plasminogen activator ,recurrent pregnancy loss ,renin ,plasminogen activator inhibitor-1 ,Article ,polymorphism - Abstract
Recurrent pregnancy loss (RPL) is defined as two or more consecutive pregnancy losses prior to 20 weeks of gestational age. Various factors, including immune dysfunction, endocrine disorders, coagulation abnormality, and genetic disorders influence RPL. In particular, plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator (tPA), and renin (REN) have important roles in the thrombotic and thrombolytic systems, and abnormal expression of these genes have a reported negative correlation with pregnancy maintenance. Moreover, some polymorphisms of the three genes are related to expression levels and thrombotic disorder. Therefore, we investigated whether polymorphisms of PAI-1, tPA, and REN are linked to RPL. Genotyping of the six polymorphisms (PAI-1 rs11178, rs1050955, tPA rs4646972, rs2020918, REN rs1464816, and rs5707) was performed using polymerase chain reaction (PCR)-restriction fragment length polymorphism and associations of the polymorphisms with RPL were evaluated by statistical analysis. The polymorphism PAI-1 rs1050955 GA+AA was associated with decreased RPL risk (AOR, 0.528; 95% CI 0.356–0.781; p = 0.001) as was the REN 10795 rs5707 GG genotype (AOR, 0.487; 95% CI 0.301–0.787; p = 0.003). In contrast, the tPA rs4646972 II genotype correlated with increased RPL risk (AOR, 1.606; 95% CI, 1.047–2.463; p = 0.030). This study provides evidence that tPA Alu rs4646972 may contribute to the risk of idiopathic RPL, but PAI-1 12068 rs1050955 and REN 10795 rs5707 are associated with a decreased risk of RPL. Therefore, these alleles may be useful as biomarkers to evaluate the risk of RPL.
- Published
- 2021
20. Effect of soaking temperature on soaking characteristics of soybean (Glycine max) during rehydration process
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Hyeon Woo Park, Won Byong Yoon, and Won Young Han
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0106 biological sciences ,0301 basic medicine ,Moisture ,Chemistry ,030106 microbiology ,Organic Chemistry ,Bioengineering ,01 natural sciences ,03 medical and health sciences ,010608 biotechnology ,Scientific method ,Glycine ,Food science ,Water content - Abstract
The effect of soaking temperature on the moisture uptake and the protein loss of soybeans during soaking process investigated. As the soaking temperature increased, the soaking rate significantly increased and Peleg model was suitable for describing the soaking characteristics of the soybean with high R2 values (>0.991). The soaking time to achieve the target moisture content of soybean (130%) was estimated to be 12.6, 3.11 and 2.31 h at 25, 35 and 45 ℃, respectively. Peleg model well described the protein loss kinetics of soybean during soaking with high R2 values (>0.941). The results showed that the protein loss of soybean at the target moisture content were 35.2, 93.1 and 103.0 mg/g at 25, 35 and 45 ℃, respectively. In this study, the optimum soaking condition for quality of soybean was 12.6 h of soaking time at 25 ℃.
- Published
- 2019
21. Association between HOX Transcript Antisense RNA Single-Nucleotide Variants and Recurrent Implantation Failure
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Young Ran Kim, Hyeon Woo Park, Jeong Yong Lee, Nam Keun Kim, Eun Hee Ahn, Woo Sik Lee, and Ji Hyang Kim
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Biology ,Catalysis ,Inorganic Chemistry ,Andrology ,lcsh:Chemistry ,Genotype ,polycyclic compounds ,implantation ,Epigenetics ,single nucleotide variant ,Physical and Theoretical Chemistry ,Hox gene ,Molecular Biology ,lcsh:QH301-705.5 ,Spectroscopy ,RIF ,long non-coding RNA ,Organic Chemistry ,Haplotype ,HOTAIR ,General Medicine ,Long non-coding RNA ,Computer Science Applications ,Antisense RNA ,lcsh:Biology (General) ,lcsh:QD1-999 ,pregnancy ,HOX Transcript Antisense RNA - Abstract
Recurrent implantation failure (RIF) refers to the occurrence of more than two failed in vitro fertilization–embryo transfers (IVF-ETs) in the same individual. RIF can occur for many reasons, including embryo characteristics, immunological factors, and coagulation factors. Genetics can also contribute to RIF, with some single-nucleotide variants (SNVs) reported to be associated with RIF occurrence. We examined SNVs in a long non-coding RNA, homeobox (HOX) transcript antisense RNA (HOTAIR), which is known to affect cancer development. HOTAIR regulates epigenetic outcomes through histone modifications and chromatin remodeling. We recruited 155 female RIF patients and 330 healthy controls, and genotyped HOTAIR SNVs, including rs4759314, rs920778, rs7958904, and rs1899663, in all participants. Differences in these SNVs were compared between the patient and control groups. We identified significant differences in the occurrence of heterozygous genotypes and the dominant expression model for the rs1899663 and rs7958904 SNVs between RIF patients and control subjects. These HOTAIR variants were associated with serum hemoglobin (Hgb), luteinizing hormone (LH), total cholesterol (T. chol), and blood urea nitrogen (BUN) levels, as assessed by analysis of variance (ANOVA). We analyzed the four HOTAIR SNVs and found significant differences in haplotype patterns between RIF patients and healthy controls. The results of this study showed that HOTAIR is not only associated with the development of cancer but also with pregnancy-associated diseases. This study represents the first report showing that HOTAIR is correlated with RIF.
- Published
- 2021
22. A study of associations between CUBN, HNF1A, and LIPC gene polymorphisms and coronary artery disease
- Author
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Jung Hoon Sung, Eun-Ju Ko, In Jai Kim, Eun Gyo Kim, Han Sung Park, Hyeon Woo Park, Chang Soo Ryu, Jeong Yong Lee, and Nam Keun Kim
- Subjects
0301 basic medicine ,Genetic Markers ,Male ,medicine.medical_specialty ,lcsh:Medicine ,Receptors, Cell Surface ,Coronary Artery Disease ,030204 cardiovascular system & hematology ,Gastroenterology ,Polymorphism, Single Nucleotide ,Coronary artery disease ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Gene Frequency ,Polymorphism (computer science) ,Internal medicine ,Genotype ,Exome Sequencing ,medicine ,Humans ,Genetic Predisposition to Disease ,Hepatocyte Nuclear Factor 1-alpha ,lcsh:Science ,Exome sequencing ,Multidisciplinary ,Polymorphism, Genetic ,Cholesterol ,business.industry ,lcsh:R ,Case-control study ,Odds ratio ,Lipase ,Middle Aged ,medicine.disease ,HNF1A ,030104 developmental biology ,Logistic Models ,chemistry ,Case-Control Studies ,lcsh:Q ,Female ,business - Abstract
The aim of this study was to identify novel genetic markers related to coronary artery disease (CAD) using a whole-exome sequencing (WES) approach and determine any associations between the selected gene polymorphisms and CAD prevalence. CUBN, HNF1A and LIPC gene polymorphisms related to CAD susceptibility were identified using WES screening. Possible associations between the five gene polymorphisms and CAD susceptibility were examined in 452 CAD patients and 421 control subjects. Multivariate logistic regression analyses indicated that the CUBN rs2291521GA and HNF1A rs55783344CT genotypes were associated with CAD (GG vs. GA; adjusted odds ratio [AOR] = 1.530; 95% confidence interval [CI] 1.113–2.103; P = 0.002 and CC vs. CT; AOR = 1.512; 95% CI 1.119–2.045; P = 0.007, respectively). The CUBN rs2291521GA and HNF1A rs55783344CT genotype combinations exhibited a stronger association with CAD risk (AOR = 2.622; 95% CI 1.518–4.526; P = 0.001). Gene-environment combinatorial analyses indicated that the CUBN rs2291521GA, HNF1A rs55783344CT, and LIPC rs17269397AA genotype combination and several clinical factors (fasting blood sugar (FBS), high-density lipoprotein (HDL), and low-density lipoprotein (LDL) levels) were associated with increased CAD risk. The CUBN rs2291521GA, HNF1A rs55783344CT, and LIPC rs17269397AA genotypes in conjunction with abnormally elevated cholesterol levels increase the risk of developing CAD. This exploratory study suggests that polymorphisms in the CUBN, HNF1A, and LIPC genes can be useful biomarkers for CAD diagnosis and treatment.
- Published
- 2020
23. Effect of Dehydration on the Rheological Measurement of Surimi Paste in Cone-Plate Rheometry: Heat and Mass Transfer Simulation
- Author
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Hyeon Woo Park, Jae Won Park, and Won Byong Yoon
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Materials science ,Moisture ,Rheometry ,surimi ,Process Chemistry and Technology ,Analytical chemistry ,alaska pollock ,Bioengineering ,medicine.disease ,Thermal diffusivity ,lcsh:Chemical technology ,lcsh:Chemistry ,lcsh:QD1-999 ,Mass transfer ,Heat transfer ,medicine ,Chemical Engineering (miscellaneous) ,rheology ,lcsh:TP1-1185 ,Dehydration ,computational fluid dynamics temperature sweep ,Elastic modulus ,Water content - Abstract
Moisture transfer characteristics of Alaska pollock (AP) surimi were investigated at various temperatures. The effective moisture diffusivity increased from 5.50 ×, 10&minus, 11 to 2.07 ×, 9 m2/s as the temperature increased from 30 °, C to 90 °, C. In order to investigate the mass and heat transfer characteristics of AP surimi, the simulation model was developed and evaluated by root-mean-square error (RMSE) (<, 2.95%). Rheological properties of AP surimi were investigated at different heating rates (1 °, C/min, 5 °, C/min, 10 °, C/min, 20 °, C/min and 30 °, C/min). As heating rate increased to 20 °, C/min, elastic modulus (G&rsquo, ) significantly diminished. The diminished G&rsquo, could be explained by impaired gel during temperature sweep supported by the predicted temperature distribution in the simulation model. Changes in moisture content of AP surimi during temperature sweep were also measured and predicted by the simulation model. The results showed the decreased amount of moisture content significantly increased as heating rate increased.
- Published
- 2020
24. The effect of water activity and temperature on the inactivation of Enterococcus faecium in peanut butter during superheated steam sanitation treatment
- Author
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Hyeon Woo Park, Abigail B. Snyder, V.M. Balasubramaniam, and Jie Xu
- Subjects
Temperature sensitivity ,Water activity ,Peanut butter ,biology ,Chemistry ,Inactivation kinetics ,Superheated steam ,010401 analytical chemistry ,food and beverages ,04 agricultural and veterinary sciences ,Contamination ,biology.organism_classification ,040401 food science ,01 natural sciences ,Microbial inactivation ,0104 chemical sciences ,0404 agricultural biotechnology ,Food science ,Food Science ,Biotechnology ,Enterococcus faecium - Abstract
The objective of this study was to investigate the inactivation kinetics of Enterococcus faecium in peanut butter under different water activities (aw) and superheated steam temperatures. Peanut butters were prepared at 4 different initial water activities (0.19, 0.40, 0.60, and 0.80) and E. faecium was inoculated into the peanut butter (7.4–8.7 log CFU/g). The inoculated peanut butter samples were exposed at 4 different superheated steam temperatures (125 °C, 175 °C, 225 °C, and 250 °C). Survivor data were modelled using Weibull and log-linear models to describe the inactivation kinetics of E. faecium. The decimal reduction times (D-value), temperature sensitivity (zT) and aw sensitivity (zaw) of the D-value were determined from a log-linear model, and inactivation parameters from the Weibull model were also evaluated. An increase in aw of peanut butter and superheated steam temperature decreased the D-value of E. faecium. The zaw-value and zT-value were determined to be 0.60 ± 0.09 and 194.66 ± 40.69 °C, respectively (R2 > 0.89). The inactivation kinetics of E. faecium on surfaces contaminated with peanut butter can provide comprehensive information to superheated steam sanitation treatment which may be applied to environmental surfaces for effective microbial inactivation without the introduction of water.
- Published
- 2021
25. Influence of water activity and acidity on Bacillus cereus spore inactivation during combined high pressure-thermal treatment
- Author
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Ahmed E. Yousef, Jerish Joyner Janahar, V.M. Balasubramaniam, Jie Xu, and Hyeon Woo Park
- Subjects
0106 biological sciences ,biology ,Water activity ,Chemistry ,Inactivation kinetics ,fungi ,Bacillus cereus ,04 agricultural and veterinary sciences ,Thermal treatment ,biology.organism_classification ,040401 food science ,01 natural sciences ,Endospore ,Spore ,0404 agricultural biotechnology ,Cereus ,010608 biotechnology ,High pressure ,Food science ,Food Science - Abstract
Understanding the inactivation kinetics of bacterial spores during combined pressure-thermal processing is essential for process design. The knowledge on the influence of pH and water activity (aw) during combined pressure-thermal treatment is limited. Experiments were conducted using Bacillus cereus spores suspended in citrate-phosphate buffers, adjusted to different levels of pH (3.8–7.3) and aw (0.80–0.99). Spores were then treated with a pressure-heat combination (600 MPa, 70 °C) using a laboratory-scale high-pressure kinetic tester. Linear regression and Weibull models were used to fit the experimental data. The kinetic parameters of the spores inactivation estimated from the models were plotted as a function of pH and aw. Results showed that the inactivation kinetic curves were characterized by tailing, particularly at low aw levels. The log reduction of B. cereus spores decreased with the decrease of aw. During pressure-thermal treatment, the changes in acidity values for a given water activity have limited influence on decimal reduction values of the spores. Study findings will be helpful for designing pressure-thermal processes to produce microbially safe products with varying water activity and acidity levels.
- Published
- 2021
26. Effect of drying and grinding characteristics of colored potato (Solanum tuberosumL.) on tribology of mashed colored potato paste
- Author
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Hyeon Woo Park and Won Byong Yoon
- Subjects
0301 basic medicine ,Materials science ,Colored potato ,General Chemical Engineering ,lcsh:TX341-641 ,mashed potato ,Industrial and Manufacturing Engineering ,03 medical and health sciences ,Mouthfeel ,0404 agricultural biotechnology ,Rheology ,Dynamic modulus ,drying ,Food science ,Mashed potato ,030109 nutrition & dietetics ,lcsh:TP368-456 ,Moisture ,04 agricultural and veterinary sciences ,General Chemistry ,Tribology ,anthocyanins ,grinding ,040401 food science ,Grinding ,secado ,ginding ,antocianinas ,rheology ,tribulogy ,tituración ,tribulogía ,reología ,puré de papa ,papa de colores ,lcsh:Food processing and manufacture ,tribology ,Particle size ,lcsh:Nutrition. Foods and food supply ,Food Science - Abstract
The mouthfeel of mashed potato prepared with steamed purple flesh potato (SPFP) was investigated by measuring tribological and rheological characteristics. Mathematical models describing pre-processes such as drying and grinding associated with physical properties of mashed potato were also explored. The effect of drying temperature (60, 70, 80, and 90°C) on quality changes (moisture and anthocyanin content) of SPFP was successfully described (R2 > 0.9583). The sigmoid model was suitably applied to estimate particle sizes of dried SPFP during grinding (R2 > 0.9864). As the particle size of mashed SPFP increased, friction coefficient increased, and storage and loss modulus decreased. Taste, smoothness, and after-feel sensation were increased as particle sizes decreased, while appearance and odor showed no significant differences. To predict the sensory property using tribology and rheology, the specific conditions were successfully determined (R2 > 0.9926). A partir de la medición de las características tribológicas y reológicas se investigó la sensación producida en la boca por el puré de papas preparado con pulpa de papa morada al vapor (PPMV). Asimismo, se examinaron modelos matemáticos que describen procesos previos, como el secado y la trituración, asociados con las propiedades físicas del puré de papa. Se registró correctamente el efecto que distintas temperaturas de secado (60, 70, 80 y 90°C) tienen en los cambios de calidad (contenido de humedad y de antocianina) de la PPMV (R2 > 0,9583). Además, el modelo sigmoidal se aplicó de manera adecuada a fin de estimar el tamaño de las partículas de PPMV secadas durante la trituración (R2 > 0,9864). Se constató que cuando el tamaño de la partícula de PPMV era mayor se elevó el coeficiente de fricción y disminuyeron los módulos de almacenamiento y de pérdida. El sabor, la suavidad y la sensación posterior se incrementaron a medida que el tamaño de las partículas fue disminuyendo, mientras que la apariencia y el aroma no presentaron diferencias significativas. Se determinaron correctamente las condiciones específicas para pronosticar las propiedades sensoriales utilizando tribología y reología (R2 > 0,9926).
- Published
- 2017
27. A Comparative Study on the Ferroelectric Performances in Atomic Layer Deposited Hf
- Author
-
Baek Su, Kim, Seung Dam, Hyun, Taehwan, Moon, Keum, Do Kim, Young Hwan, Lee, Hyeon Woo, Park, Yong Bin, Lee, Jangho, Roh, Beom Yong, Kim, Ho Hyun, Kim, Min Hyuk, Park, and Cheol Seong, Hwang
- Subjects
Wake-up phenomenon ,Nano Express ,Atomic layer deposition ,Metal-organic precursor ,Ferroelectric Hf0.5Zr0.5O2 film ,Interfacial layer - Abstract
The chemical, physical, and electrical properties of the atomic layer deposited Hf0.5Zr0.5O2 thin films using tetrakis(ethylmethylamino) (TEMA) and tetrakis(dimethylamino) (TDMA) precursors are compared. The ligand of the metal-organic precursors strongly affects the residual C concentration, grain size, and the resulting ferroelectric properties. Depositing Hf0.5Zr0.5O2 films with the TDMA precursors results in lower C concentration and slightly larger grain size. These findings are beneficial to grow more ferroelectric-phase-dominant film, which mitigates its wake-up effect. From the wake-up test of the TDMA-Hf0.5Zr0.5O2 film with a 2.8 MV/cm cycling field, the adverse wake-up effect was well suppressed up to 105 cycles, with a reasonably high double remanent polarization value of ~40 μC/cm2. The film also showed reliable switching up to 109 cycles with the 2.5 MV/cm cycling field without involving the wake-up effect but with the typical fatigue behavior.
- Published
- 2019
28. Effect of water activity on inactivation of Listeria monocytogenes using gaseous chlorine dioxide – A kinetic analysis
- Author
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Lihan Huang, Hyeon Woo Park, Guoying Chen, and Cheng-An Hwang
- Subjects
food.ingredient ,Water activity ,Inactivation kinetics ,Kinetic analysis ,Colony Count, Microbial ,medicine.disease_cause ,Microbiology ,03 medical and health sciences ,chemistry.chemical_compound ,food ,Listeria monocytogenes ,Antimicrobial effect ,medicine ,Agar ,030304 developmental biology ,0303 health sciences ,Chlorine dioxide ,Chromatography ,030306 microbiology ,Water ,Oxides ,Kinetics ,Chemical reaction kinetics ,chemistry ,Gases ,Chlorine Compounds ,Disinfectants ,Food Science - Abstract
The aim of this study was to investigate the effect of water activity (aw) on inactivation of Listeria monocytogenes using gaseous chlorine dioxide (ClO2 (g)) under room temperature. Surface-inoculated tryptic soy agar (TSA) plates adjusted to 9 different water activity levels ranging from 0.994 to 0.429 were used as samples exposed to ClO2 (g) at 150, 250, and 350 ppm for different durations of treatment time. Results showed that the antimicrobial effect of ClO2 (g) significantly decreases as the aw level and ClO2 (g) concentration decrease. Nonlinear models, such as the modified Chick model and the Weibull model, were used to describe the inactivation kinetics of L. monocytogenes. The results showed that the modified Chick model, which is based on chemical reaction kinetics, was more suitable to describe the inactivation of L. monocytogenes (RMSE
- Published
- 2021
29. Improvement of Domestic Construction Re-Education through Status Analysis
- Author
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Yongwoon Cha, Chang-Taek Hyun, Myung-Jin Son, In-Seok Park, and Hyeon Woo Park
- Subjects
Construction management ,Engineering ,business.industry ,010401 analytical chemistry ,0211 other engineering and technologies ,Analytic hierarchy process ,02 engineering and technology ,Plan (drawing) ,Environmental economics ,Investment (macroeconomics) ,01 natural sciences ,Re education ,0104 chemical sciences ,Construction industry ,Order (exchange) ,021105 building & construction ,Operations management ,business - Abstract
In the past, the domestic construction industry mainly comprised quantitative investment through the supply of labor force, however, there have recently been opinions that there is a need for qualitative investment in the workers in order to obtain competitiveness in construction markets. Accordingly, there are much re-education courses for workers in the construction industry, but there is much negative awareness as to the efficiency of the current re-education course due to many problems. This study aimed to examine the problems o f currently executed re-education courses and proposed an improvement plan for the qualitative enhancement of domestic construction re-education. Thus, a multiple regression analysis was conducted to deduce two core problems an improvement plan. The improvement plan for the problems comprised the NCS/CDP-based integrative education program through an AHP. The contribution of this paper will result in the execution of a more effective construction industry re-education program, and the result of such program to achieve qualitative growth in the workers in the construction industry
- Published
- 2016
30. MiR-10a, 27a, 34b/c, and 300 Polymorphisms are Associated with Ischemic Stroke Susceptibility and Post-Stroke Mortality
- Author
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Seung Hun Oh, Kee Ook Lee, Nam Keun Kim, Ok Joon Kim, Chang Soo Ryu, Han Sung Park, Hyeon Woo Park, Eun Ju Ko, Jeong Yong Lee, and Hui Jeong An
- Subjects
medicine.medical_specialty ,diagnosis ,survival ,Gastroenterology ,Article ,General Biochemistry, Genetics and Molecular Biology ,polymorphism ,law.invention ,law ,Internal medicine ,microRNA ,Genotype ,Gene expression ,ischemic stroke ,Medicine ,Ecology, Evolution, Behavior and Systematics ,Polymerase chain reaction ,business.industry ,Mortality rate ,Paleontology ,Increased risk ,Space and Planetary Science ,Ischemic stroke ,Post stroke ,business - Abstract
A recent study of the ischemic stroke described the roles played by miRNAs in the downregulation of specific cell-cycle gene expression and it is thought to require the development of biomarkers for the prognostic of ischemic stroke. Here, we hypothesized that four miRNA polymorphisms (miR-10a, miR-27a, miR-34b/c, and miR-300) may affect stroke susceptibility and mortality. Blood samples were collected from 530 patients and 403 controls. Genetic polymorphisms were detected by polymerase chain reaction (PCR)-restriction fragment length polymorphism analysis and real-time PCR. We found that the miR-300 rs12894467 TC genotype and the dominant model (AOR: 2.069, p-value: 0.017, AOR: 1.931, p-value: 0.027) were significantly associated with an increased risk for the ischemic stroke subtype. In Cox proportional hazard regression models, the miR-10a rs3809783 A>, T and miR-34b/c rs4938723 T>, C polymorphisms were associated with the mortality rates among ischemic stroke patients. We found that a miR-300 polymorphism was associated with increased ischemic stroke susceptibility among the Korean population. Additionally, polymorphisms in miR-10a and miR-34b/c were associated with the increased or decreased mortality of ischemic stroke patients. This study marks the first report of an association between ischemic stroke and miRNA polymorphisms (miR-10aA>, T, miR-27aT>, C, miR-34b/cT>, C, and miR-300T>, C) in the Korean population.
- Published
- 2020
31. Computational Fluid Dynamics (CFD) Modelling and Application for Sterilization of Foods: A Review
- Author
-
Hyeon Woo Park and Won Byong Yoon
- Subjects
0106 biological sciences ,Computer science ,Energy transfer ,Mechanical engineering ,Bioengineering ,computational fluid dynamics ,Computational fluid dynamics ,lcsh:Chemical technology ,01 natural sciences ,Physics::Fluid Dynamics ,lcsh:Chemistry ,0404 agricultural biotechnology ,Computer Science::Computational Engineering, Finance, and Science ,010608 biotechnology ,Fluid dynamics ,computer simulation ,Chemical Engineering (miscellaneous) ,lcsh:TP1-1185 ,thermal processing ,Computer Science::Distributed, Parallel, and Cluster Computing ,business.industry ,Process Chemistry and Technology ,Simulation modeling ,sterilization ,04 agricultural and veterinary sciences ,Flow pattern ,Physics::Classical Physics ,040401 food science ,Computer Science::Performance ,lcsh:QD1-999 ,business ,CFD - Abstract
Computational fluid dynamics (CFD) is a powerful tool to model fluid flow motions for momentum, mass and energy transfer. CFD has been widely used to simulate the flow pattern and temperature distribution during the thermal processing of foods. This paper discusses the background of the thermal processing of food, and the fundamentals in developing CFD models. The constitution of simulation models is provided to enable the design of effective and efficient CFD modeling. An overview of the current CFD modeling studies of thermal processing in solid, liquid, and liquid-solid mixtures is also provided. Some limitations and unrealistic assumptions faced by CFD modelers are also discussed.
- Published
- 2018
32. Optimal Interface Design between Short-Range Air Defense Missile System and Dissimilar Combat Systems
- Author
-
Hyeon-Woo Park
- Subjects
Engineering ,Missile ,Aeronautics ,business.industry ,Range (aeronautics) ,Interface (computing) ,Command and control ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,Interface design ,business ,Missile system - Abstract
The warship is run based on the combat system which shares tactical information collected by target detection systems and navigation devices across a network, and conducts the command and control of weapons from target detection to kill assessment. The short-range air defense missile system defends a warship from anti-ship missiles, aircraft, helicopter and other threats in order to contribute to the survival of a warship and the success of missions. The short-range air defense missile system is applied to a various combat systems. In this paper, we have proposed the interface design between the short-range air defense missile and dissimilar combat systems. To employ the short-range air defense missile at dissimilar combat systems, each system is driven by independent processor, and the tasks which are performed by each system are assigned. The information created by them is exchanged through the interface, and the flow of messages is designed.Key Words : Dissimilar Combat Systems(이기종 함정 전투체계), Short-Range Air Defense Missile System(단거리 대공방어유도탄체계), Interface(연동), Flow of Messages(메시지 흐름)
- Published
- 2015
33. Factors Influencing Subjective Well-Being of Immigrant Wives
- Author
-
박현우(Hyeon Woo Nam), 김유영(Hyeon Woo Park), and 남현우(You Young Kim)
- Subjects
Social group ,First language ,media_common.quotation_subject ,Immigration ,Public institution ,Club ,Psychology ,Social psychology ,Welfare ,Socioeconomic status ,Acculturation ,media_common - Abstract
This study investigated the factors that influence subjective well-being of immigrant wives in Korea. We initially grouped the factors into 3 categories: personal, domestic, and social. For personal factors, we included couple`s age difference, reason for entry, religion, marital duration, employment status, economical status, acculturation to Korean culture, acquisition of Korean language, and ego-resiliency. For domestic factors we included marriage process, reason for marriage, husbands` understanding of wife`s native language, husbands` understanding of wife`s culture, marital satisfaction, existence of children, head of the household, and parenting efficacy. Finally for social factors, awareness of welfare services and systems, use of public institutions and civil organizations, and participation in social groups were included. We recruited 256 immigrant wives who live in Asan City, Chungnam Province and the data were analyzed by multiple linear regression. The factors that statistically significant were: ego-resiliency, marital duration, acculturation to Korean culture and economic status among personal factors; parenting efficacy, marital satisfaction and marriage process (married without a matchmaker) among domestic factors; participation in self-help group of women from the same mother country, awareness of welfare services and systems, participation in hobby club, and participation in fraternal/religious society among social factors. It is hoped that this paper will yield general insights into subjective well-being of immigrant wives and may help them to develop inner talent and strength.
- Published
- 2013
34. Controlled cyclopolymerisation of 1,7-octadiyne derivatives using Grubbs catalyst
- Author
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In Sun Lee, Tae-Lim Choi, Eun-Hye Kang, and Hyeon Woo Park
- Subjects
chemistry.chemical_classification ,Grubbs' catalyst ,chemistry.chemical_compound ,Monomer ,chemistry ,Polymerization ,Polymer chemistry ,Copolymer ,General Chemistry ,Polymer ,Conjugated system ,Ring (chemistry) ,Catalysis - Abstract
Cyclopolymerisation of 1,6-heptadiyne derivatives by Grubbs catalysts gives the conjugated polymers containing a five-membered ring repeat unit. The first example of cyclopolymerisation of 1,7-octadiyne derivatives is demonstrated here to give a new class of conjugated polymer that contains six-memebered rings. This polymerisation was very challenging and efficient cyclopolymerisation was achieved only with monomers that showed a significant Thorpe–Ingold effect. By using a third-generation Grubbs catalyst, we obtained the polymers with excellent molecular weight control and narrow PDIs. This controlled polymerisation allowed the synthesis of diblock copolymers containing five- and six-membered rings, respectively, from 1,6-heptadiyne and the 1,7-octadiyne derivatives.
- Published
- 2012
35. Research Update: Diode performance of the Pt/Al2O3/two-dimensional electron gas/SrTiO3 structure and its time-dependent resistance evolution
- Author
-
Taehwan Moon, Han Joon Kim, Keum Do Kim, Min Hyuk Park, Hyeon Woo Park, Sang Woon Lee, Yu Jin Kim, Cheol Seong Hwang, Seung Dam Hyun, Young Hwan Lee, and Hae Jun Jung
- Subjects
Materials science ,lcsh:Biotechnology ,Analytical chemistry ,02 engineering and technology ,01 natural sciences ,law.invention ,law ,Vacancy defect ,lcsh:TP248.13-248.65 ,0103 physical sciences ,General Materials Science ,Time domain ,010306 general physics ,Diode ,business.industry ,General Engineering ,021001 nanoscience & nanotechnology ,lcsh:QC1-999 ,Amorphous solid ,Capacitor ,Electrode ,Relaxation (physics) ,Optoelectronics ,0210 nano-technology ,Fermi gas ,business ,lcsh:Physics - Abstract
Time domain electric pulse measurements were conducted on a capacitor consisting of a Pt film as the top electrode, atomic-layer-deposited 6.5-nm-thick amorphous Al2O3 as the dielectric layer, and two-dimensional electron gas (2DEG) at the interface between Al2O3 and SrTiO3 as the bottom electrode. The sample showed highly useful current-voltage characteristics as the selector in cross-bar array resistance switching random access memory. The long-term (order of second) variation in the leakage current when the Pt electrode was positively biased was attributed to the field-induced migration of oxygen vacancies between the interior of the Al2O3 and the 2DEG region. Relaxation of the vacancy concentration occurred even at room temperature.
- Published
- 2017
36. Frobenius numbers of Pythagorean triples
- Author
-
Tae Hyun Kim, Kyeongsik Nam, Byung Keon Gil, Bon Woo Lee, Ryun Han Koo, Ji-Woo Han, Jae Hoon Lee, Hyeon Woo Park, and Poo-Sung Park
- Subjects
Combinatorics ,Algebra and Number Theory ,Coprime integers ,Integer ,Mathematics - Number Theory ,Pythagorean triple ,11D07 ,FOS: Mathematics ,Tree of primitive Pythagorean triples ,Number Theory (math.NT) ,Mathematics - Abstract
Given relatively prime integers $a_1, \dotsc, a_n$, the Frobenius number $g(a_1, \dotsc, a_n)$ is defined as the largest integer which cannot be expressed as $x_1 a_1 + \dotsb + x_n a_n$ with $x_i$ nonnegative integers. In this article, we give the Frobenius number of primitive Pythagorean triples. That is, \[ g(m^2-n^2, 2mn, m^2+n^2) = (m-1)(m^2-n^2) + (m-1)(2mn) - (m^2 + n^2). \], 6 papges
- Published
- 2014
37. Acknowledgment of priority: 'Frobenius numbers of Pythagorean triples'
- Author
-
Jae Hoon Lee, Hyeon Woo Park, Byung Keon Gil, Tae Hyun Kim, Bon Woo Lee, Ji-Woo Han, Kyeongsik Nam, Poo-Sung Park, and Ryun Han Koo
- Subjects
Combinatorics ,Algebra and Number Theory ,Pythagorean triple ,Mathematics - Published
- 2015
38. Effects of air movement in a hot air dryer on the drying characteristics of colored potato (Solanum tuberosum L.) using computational fluid dynamics.
- Author
-
Hyeon Woo Park and Won Byong Yoon
- Subjects
- *
POTATOES , *COMPUTATIONAL fluid dynamics , *HEAT transfer , *THERMAL properties , *MOISTURE - Abstract
The flow fields of hot air in the dryer for drying colored potatoes of which characteristics are highly sensitive to the temperature were simulated using computational fluid dynamics (CFD) simulation. The local air velocity decreased as the distance from the flow inlet increased. The mass and heat transfer coefficients increased from 0.666x10-2 m/s to 1.711x 10-2 m/s, and 6.555 W/(m²·K) to 16.834 W/(m2·K), respectively, as the air velocity increased from 0.207 m/s to 1.567 m/s at 60°C. The drying simulation model using the heat and mass transfer model made accurate predictions. The thermal properties of colored potato, such as the thermal conductivity and specific heat, decreased significantly from 0.440 W/(m·K) to 0.034 W/(m·K) and 3906.45 J/(kg·K) to 2198.52 J/(kg·K), respectively, as the moisture content decreased from 78% to 5%. With the variable thermal and physical properties, the heat transfer simulation model made accurate predictions of the hot-air drying characteristics for the colored potatoes, and the RMSE values for all cases were (1.85±0.27)°C. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
39. Research Update: Diode performance of the Pt/Al2O3/two-dimensional electron gas/SrTiO3 structure and its time-dependent resistance evolution.
- Author
-
Taehwan Moon, Hae Jun Jung, Yu Jin Kim, Min Hyuk Park, Han Joon Kim, Keum Do Kim, Young Hwan Lee, Seung Dam Hyun, Hyeon Woo Park, Sang Woon Lee, and Cheol Seong Hwang
- Subjects
DIODES ,ELECTRON gas ,TIME-domain analysis ,CAPACITORS ,ELECTRODES - Abstract
Time domain electric pulse measurements were conducted on a capacitor consisting of a Pt film as the top electrode, atomic-layer-deposited 6.5-nm-thick amorphous Al
2 O3 as the dielectric layer, and two-dimensional electron gas (2DEG) at the interface between Al2 O3 and SrTiO3 as the bottom electrode. The sample showed highly useful current-voltage characteristics as the selector in cross-bar array resistance switching random access memory. The long-term (order of second) variation in the leakage current when the Pt electrode was positively biased was attributed to the field-induced migration of oxygen vacancies between the interior of the Al2 O3 and the 2DEG region. Relaxation of the vacancy concentration occurred even at room temperature. [ABSTRACT FROM AUTHOR]- Published
- 2017
- Full Text
- View/download PDF
40. The transport of a hepatoprotective agent, isopropryl 2-(1-3-dithiethane-2-ylidene)-2[N-(4-methyl-th iazole-2-yl) carbamoyl] acetate (YH439), across caco-2 cell monolayers
- Author
-
Myung Gull Lee, Hyeon Woo Park, Chang-Koo Shim, and Suk Jae Chung
- Subjects
Chromatography ,Chemistry ,Organic Chemistry ,Metabolism ,Bioavailability ,Caco-2 ,In vivo ,Drug Discovery ,Molecular Medicine ,Efflux ,Hepatoprotective Agent ,Solubility ,Drug metabolism ,Nuclear chemistry - Abstract
Isopropryl 2-(1-3-dithiethane-2-ylidene)-2[N-(4-methyl-thiazole-2-yl) carbamoyl] acetate (YH439) is currently under phase II clinical trials by the Yuhan Research Center for use as a hepatoprotective agent. Unfortunately, the oral bioavailbility of YH439, which is sparingly soluble in water (i.e., 0.3μg/ml or 0.91μM at room temperature), reportedly, is negligible regardless of the dose administered to rats in the 10-300 mg/kg range. The bioavailability of the compound increased up to 24%, when administered in the form of a micellar solution (700 μg/ml or 2.1 mM for YH439) at a dose of 10 mg/kg, suggesting that its limited solubility is associated with its negligible bioavailability. In order to obtain additional information concerning the bioavailability of YH439, the mechanism(s) involved in gastrointestinal (GI) absorption were investigated in the present study. For this purpose, the transport of YH430 across a Caco-2 cell monolayer was measured in a Transwell(r). A permeability of 4.07×10-5 cm/s was obtained for the absorptive (i.e., apical to basolateral direction) transport of 0.42 μM YH439, implicating that the in vivo GI absorption is nearly complete. The absorptive transport exhibited a slight concentration-dependency with an intrinsic clearance (CLi) of 0.38 μL/cm2/sec, which accounted for 28.1% of the total intrinsic clearance (i.e., CLi plus the intrinsic clearance for the linear component) of the transport. Thus, saturation of the absorption process appears to be a minor factor in limiting the bioavailability of the compound. The apparent permeability of YH439 from the basolateral to the apical direction (i.e., efflux, 6.67×10-5 cm/s) was comparable to that for absorptive transport, but, interestingly, a more distinct concentration-dependency was observed for this transport. However, the efflux does not appear to influence the bioavailability of the compound, as evidenced by the sufficiently high permeability in the absorption direction. Rather, a reportedly extensive first-pass hepatic metabolism appears to be a principal factor in limiting the bioavailability. In this respect, reducing the first-pass metabolism by some means would lead to a higher bioavailability of the compound. Thus, elevation of the absorption rate of YH439 becomes a necessity. From a practical point of view, increasing the concentration of YH439 in the GI fluid appears to be a feasible way to increase the absorption rate, because the compound is primarily absorbed via a linear mechanism. In summary, the solubilization of YH439, as previously demonstrated for a micellar solution of the compound, appears to be a practical way to increase the oral bioavailability of YH439.
- Published
- 2002
41. Review of ferroelectric field‐effect transistors for three‐dimensional storage applications
- Author
-
Hyeon Woo Park, Jae‐Gil Lee, and Cheol Seong Hwang
- Subjects
depolarization ,domain pattern ,ferroelectric field‐effect transistor ,interference ,NAND architecture ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
Abstract The ferroelectric field‐effect transistor (FeFET) is one of the leading contenders to succeed charge‐trap‐based flash memory (CTF) devices in the current vertically‐integrated NAND flash storage market. The operation of a FeFET is based on the field‐effect in the channel of the FET that is exerted by the uncompensated ferroelectric bound charge, which is also the fundamental source of the depolarization effect. This paper briefly reviews the current status of CTF‐based NAND flash memory as a benchmark for FeFET. Then, a one‐dimensional model based on a load‐line analysis of FeFET technology is presented. The paper subsequently deals with the two‐dimensional domain effect in nano‐sized NAND‐type FeFET devices. While NAND‐type FeFET operation is likely, current ferroelectric materials with high remanent polarization (Pr) of ∼10 μCcm‐2 and coercive field (Ec) of ∼1 MVcm‐1 are not feasible for use in such devices. This is fundamentally due to the high depolarization field induced by the unnecessarily high Pr, which not only destabilizes the memory state but also induces a severe interference effect between neighboring cells. Therefore, a new ferroelectric material with a moderately low Pr and higher Ec > ∼3 MVcm‐1 is necessary, along with structural innovation to minimize the interference effect.
- Published
- 2021
- Full Text
- View/download PDF
42. Diode Property and Positive Temperature Coefficient of Resistance of Pt/Al2O3/Nb:SrTiO3
- Author
-
Taehwan Moon, Hyun Jae Lee, Keum Do Kim, Young Hwan Lee, Seung Dam Hyun, Hyeon Woo Park, Yong Bin Lee, Baek Su Kim, and Cheol Seong Hwang
- Subjects
barrier height ,diodes ,Nb‐doped SrTiO3 ,positive temperature coefficient of resistance ,Electric apparatus and materials. Electric circuits. Electric networks ,TK452-454.4 ,Physics ,QC1-999 - Abstract
Abstract The rectification of the Pt/amorphous Al2O3 (a‐AO)/Nb‐doped SrTiO3 (NSTO) structure with excellent applicability as a selector for crossbar array resistive switching random access memory is introduced. The maximum forward/reverse current ratio exceeds 106, and the nonlinearity is also as high as 106 at room temperature. The barrier height at the a‐AO/NSTO interface is investigated via X‐ray photoelectron spectroscopy and is found to be 1.57 eV. The expected conduction mechanism is trap‐assisted tunneling in the forward bias condition. The barrier height at the Pt/a‐AO interface is examined by fitting the current–voltage results at various temperatures according to the Fowler–Nordheim transport mechanism, under the reverse bias condition, and it is found to be 2.75 eV. Moreover, the temperature dependence measurement of the current–voltage characteristics exhibits the positive temperature coefficient of resistance (PTCR) effect in reverse bias. This PTCR effect can be understood from the electron trapping of the acceptor‐like states at the a‐AO/NSTO interface with increasing temperature. The involvement of the PTCR effect under the reverse bias condition and the slight increase in the forward current further enhance the diode performance up to 107 at 70 °C, which is the highly promising performance of the present structure.
- Published
- 2018
- Full Text
- View/download PDF
43. Association between HOX Transcript Antisense RNA Single-Nucleotide Variants and Recurrent Implantation Failure
- Author
-
Jeong Yong Lee, Eun Hee Ahn, Hyeon Woo Park, Ji Hyang Kim, Young Ran Kim, Woo Sik Lee, and Nam Keun Kim
- Subjects
RIF ,pregnancy ,long non-coding RNA ,single nucleotide variant ,implantation ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Recurrent implantation failure (RIF) refers to the occurrence of more than two failed in vitro fertilization–embryo transfers (IVF-ETs) in the same individual. RIF can occur for many reasons, including embryo characteristics, immunological factors, and coagulation factors. Genetics can also contribute to RIF, with some single-nucleotide variants (SNVs) reported to be associated with RIF occurrence. We examined SNVs in a long non-coding RNA, homeobox (HOX) transcript antisense RNA (HOTAIR), which is known to affect cancer development. HOTAIR regulates epigenetic outcomes through histone modifications and chromatin remodeling. We recruited 155 female RIF patients and 330 healthy controls, and genotyped HOTAIR SNVs, including rs4759314, rs920778, rs7958904, and rs1899663, in all participants. Differences in these SNVs were compared between the patient and control groups. We identified significant differences in the occurrence of heterozygous genotypes and the dominant expression model for the rs1899663 and rs7958904 SNVs between RIF patients and control subjects. These HOTAIR variants were associated with serum hemoglobin (Hgb), luteinizing hormone (LH), total cholesterol (T. chol), and blood urea nitrogen (BUN) levels, as assessed by analysis of variance (ANOVA). We analyzed the four HOTAIR SNVs and found significant differences in haplotype patterns between RIF patients and healthy controls. The results of this study showed that HOTAIR is not only associated with the development of cancer but also with pregnancy-associated diseases. This study represents the first report showing that HOTAIR is correlated with RIF.
- Published
- 2021
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