Comparison of risk-assessment tools for cardio-cerebrovascular diseases (CVD) in male shipyard workers: a cross-sectional study

Jea Chul Ha,Jun Seok Son,Young Ouk Kim,Chang Ho Chae,Chan Woo Kim,Hyoung Ouk Park,Jun Ho Lee,Young Hoo Shin,Hyun Woo Park 대한직업환경의학회 2019 대한직업환경의학회지 Vol.31 No.-

Background: Periodic revision of assessment tools is essential to ensure risk assessment reliability and validity. Despite the recent revision of the Korea Occupational Safety and Health Agency (KOSHA) 2018, there is no evidence showing that the revision is superior to other cardio-cerebrovascular diseases (CVDs) risk-assessment tools for workplace health management. We conducted a comparative analysis using the Framingham risk score (FRS) as a gold standard to identify the most relevant CVDs risk-assessment tool for workplace health management. Methods: We included 4,460 shipyard workers who had undergone a workers" health examination during January–December 2016. Risk levels for CVDs were calculated based on the FRS, KOSHA 2013, KOSHA 2017, KOSHA 2018 (2 methods), National Health Screening Program health risk appraisal (NHS HRA) 2017, and NHS HRA 2018. Study participants were categorized into low-risk, moderate-risk, or high-risk groups. Sensitivity, specificity, correlation, and agreement of each risk-assessment tool were calculated compared with the FRS as a gold standard. For statistical analyses, Spearman"s rank correlation coefficient and the linearly weighted kappa coefficient were calculated. Results: Sensitivity of the risk assessments was highest in the KOSHA 2018 (health risk appraisal [HRA]). The FRS showed correlation coefficients of 0.354 with the KOSHA 2013, 0.396 with the KOSHA 2017, 0.386 with the KOSHA 2018, 0.505 with the KOSHA 2018 (HRA), 0.288 with the NHS HRA 2017, and 0.622 with the NHS HRA 2018. Kappa values, calculated to examine the agreement in relation to the KOSHA 2013, KOSHA 2017, KOSHA 2018, KOSHA 2018 (HRA), NHS HRA 2017, and NHS HRA 2018 with the FRS, were 0.268, 0.322, 0.352, 0.136, 0.221, and 0.559, respectively. Conclusions: The NHS HRA 2018 risk calculation method is a useful risk-assessment tool for CVDs, but only when appropriate classification criteria are applied. In order to enhance the risk-group identification capability of the KOSHA guideline, we propose to apply the classification criteria set in this study based on the risk group definition of the 2018 Korean Society of Hypertension guidelines for the management of hypertension instead of the current classification criteria of the KOSHA 2018.

Development of organic-inorganic double hole-transporting material for high performance perovskite solar cells

Jo, Jea Woong,Seo, Myung-Seok,Jung, Jae Woong,Park, Joon-Suh,Sohn, Byeong-Hyeok,Ko, Min Jae,Son, Hae Jung Elsevier 2018 Journal of Power Sources Vol.378 No.-

<P><B>Abstract</B></P> <P>The control of the optoelectronic properties of the interlayers of perovskite solar cells (PSCs) is crucial for achieving high photovoltaic performances. Of the solution-processable interlayer candidates, NiO<SUB>x</SUB> is considered one of the best inorganic hole-transporting layer (HTL) materials. However, the power conversion efficiencies (PCEs) of NiO<SUB>x</SUB>-based PSCs are limited by the unfavorable contact between perovskite layers and NiO<SUB>x</SUB> HTLs, the high density of surface trap sites, and the inefficient charge extraction from perovskite photoactive layers to anodes. Here, we introduce a new organic-inorganic double HTL consisting of a Cu:NiO<SUB>x</SUB> thin film passivated by a conjugated polyelectrolyte (PhNa-1T) film. This double HTL has a significantly lower pinhole density and forms better contact with perovskite films, which results in enhanced charge extraction. As a result, the PCEs of PSCs fabricated with the double HTL are impressively improved up to 17.0%, which is more than 25% higher than that of the corresponding PSC with a Cu:NiO<SUB>x</SUB> HTL. Moreover, PSCs with the double HTLs exhibit similar stabilities under ambient conditions to devices using inorganic Cu:NiO<SUB>x</SUB>. Therefore, this organic-inorganic double HTL is a promising interlayer material for high performance PSCs with high air stability.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Organic-inorganic double hole-transporting layer, Cu:NiO<SUB>x</SUB>/PhNa-1T HTL, was developed. </LI> <LI> Cu:NiO<SUB>x</SUB>/PhNa-1T in perovskite solar cells results in enhanced charge extraction. </LI> <LI> Decreased charge recombination in the perovskite induces enhanced <I>J</I> <SUB>SC</SUB> and FF. </LI> <LI> Devices with Cu:NiO<SUB>x</SUB>/PhNa-1T exhibit good stability under ambient conditions. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

테스트 스케줄링을 이용한 VLSI 회로의 스캔 테스터블 설계

이재선(Jea-Sun Lee),류근장(Keun-Jang Ryoo),손윤식(Yoon-Sik Son),강석주(Seok-Ju Kang),신재흥(Jea-Heung Sin),허용민(Yong-Min Hur),김윤홍(Yun-Hong Kim),임인칠(In-Chil Lim) 한국정보과학회 1993 한국정보과학회 학술발표논문집 Vol.20 No.1

본 논문에서는 직렬 스캔 설계방식의 테스트 시간과 테스트 핀의 오버헤드를 크게 줄일 수 있는 효율적인 테스터블 회로 설계 방식을 제안한다. 제안한 방식은 레지스터들의 배열을 스캔 레지스터 가중치에 기초하여 구성하고, 주어진 회로의 테스트 세션을 제안한 휴리스틱 알고리듬을 사용하여 제어 테스트 세션으로 재구성함으로써 전체 테스트 시간과 부가 하드웨어를 최소화한다. 멀티플렉서와 제어 신호를 사용하여 재구성된 세션을 수행하는 단일 스캔 경로(single scan path)를 형성함으로써, 기존의 방시고가는 달리 각 세션마다 스캔 데스트하는 경로를 다르게 구성한다. 따라서 전체 회로의 테스트 시간과 부가되는 테스트 하드웨어가 줄어든다.

Observation of melanoma cell Lines in phase contrast hard x-ray image using gold nanoparicles

( Soo Bin Son ),( Seung Han Ha ),( On Seok Lee ),( Gun Woo Lee ),( Jea Young Kim ),( Gyu Man Park ),( Sung Hee Moon ),( Sang Wook Son ),( Im Joo Rhyu ),( Sang Yeop Lee ),( Jae Bum Choo ),( Hwa Shik Yo 대한피부과학회 2008 초록집 Vol.46 No.20

Changes of depression and job stress in workers after merger without downsizing

Jun Ick Jung,Jun Seok Son,Young Ouk Kim,Chang Ho Chae,Chan Woo Kim,Hyoung Ouk Park,Jun Ho Lee,Young Hoo Shin,Jea Chul Ha 대한직업환경의학회 2018 대한직업환경의학회지 Vol.30 No.-

Background: Since the 1980s, restructuring, which includes downsizing, closures, mergers, and privatization, has expanded worldwide, and various studies have investigated its effect on health. However, previous studies have mainly focused on restructuring accompanied by massive lay-offs, and the effect of a merger on workers’ health is still controversial. This study aims to investigate changes in worker depression and job stress after a merger without downsizing, which is unusual in Korea. Methods: Repeated surveys were done in April 2014, April 2015, and April 2016 involving the participation of 209 subjects. Participants were divided into two groups, which were comprised of blue-collar workers (104) and whitecollar workers (105). Sociodemographic characteristics, including age, education level, job tenure, gender, marital status, smoking status, and alcohol consumption, were measured via a survey. To determine the level of depression, the Korean version of the Center for Epidemiologic Studies Depression Scale (CES-D) was employed, and to investigate job stress, the Korean Occupational Stress Scale-Short Form (KOSS-SF) was used. For statistical analyses, Pearson’s chi-square test, the Student’s t-test, and repeated measure analysis of variance (ANOVA) were performed. Results: The results showed that depression (CES-D, F[2, 400] = 0.466, p = 0.628) was changed but without significance and job stress (KOSS-SF, F[1.899, 379.831] = 3.192, p = 0.045) were significantly different. The betweengroup difference in the CES-D score between the blue- and white-collar workers by survey administration time was not statistically significant (F = 0.316, p = 0.574). The interaction between the survey time and occupational group was also not statistically significant (F = 0.967, p = 0.381). The between-group difference in the KOSS-SF total score was not statistically significant (F = 1.132, p = 0.289), and the interaction between the survey administration time and occupational group was also not significant (F = 0.817, p = 0.437). In the job stress subgroup analyses Job insecurity and Lack of reward showed a significant difference by survey administration time. Conclusion: This study showed that a merger without massive downsizing can cause negative health effects such as an changes in depression and increase in job stress. To improve the health of workers, both the immediate negative effects on health, and the long-term effects or their resolution over time should be considered prior to the merger.

Quantitative dermascopic image analysis for malignant melanoma

( Young Soo Heo ),( Gun Woo Lee ),( Seung Han Ha ),( On Seok Lee ),( Jea Young Kim ),( Gyu Man Park ),( Sang Wook Son ),( Min Gi Kim ),( Min Tae Kim ),( Jong Sub Moon ),( Chil Hwan Oh ) 대한피부과학회 2008 초록집 Vol.46 No.20

Whirling machine의 성능 개선을 위한 연구

이정기,양우석,손재석,한희덕,김한수,Lee Jung-Ki,Yang Woo-suk,Son Jea-seok,Han Hui-duck,Kim Han-soo 대한기계학회 2005 大韓機械學會論文集A Vol.29 No.10

In order to meet the increasing competitive pressures coupled with higher demands for component quality, whirling machines have been at the cutting edge of the automobile industry for more than 25 years. The hard whirling process can save on machining time and operation elimination. Hard whirling is done dry, without coolant. The chips carry away nearly all of the heat during cutting, leaving the workpiece cool and minimizing any thermal geometry variations. The surface finish and profile accuracy are close to grinding quality. Whirling machines usually consist of four major parts; 1) loading system that requires the necessary axial speeds, 2) head stock that needs high precision clamping and positioning system at the chuck and tailstock, 3) whirling unit that demands the high cutting speeds and cutting power fer cutting deep thread profiles and 4) unloading system that requires an easy workpiece unloading. Also, capabilities of the whirling machine can be improved by attaching a vision system to the machine. Most of whirling machines in Korean automobile industry are imported from the Leistritz company, Germany and the Hasegawa company, Japan. Tn this paper, a basic research will be performed to improve and enhance the existing whirling machines. Finally, a new Korean whirling machine will be proposed and developed.

Water Splitting Exceeding 17% Solar-to-Hydrogen Conversion Efficiency Using Solution-Processed Ni-Based Electrocatalysts and Perovskite/Si Tandem Solar Cell

Park, Hoonkee,Park, Ik Jae,Lee, Mi Gyoung,Kwon, Ki Chang,Hong, Seung-Pyo,Kim, Do Hong,Lee, Sol A,Lee, Tae Hyung,Kim, Changyeon,Moon, Cheon Woo,Son, Dae-Yong,Jung, Gwan Ho,Yang, Hong Seok,Lee, Jea Ryun American Chemical Society 2019 ACS APPLIED MATERIALS & INTERFACES Vol.11 No.37

<P>Various noble metal-free electrocatalysts have been explored to enhance the overall water splitting efficiency. Ni-based compounds have attracted substantial attention for achieving efficient oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) catalysts. Here, we show superior electrocatalysts based on NiFe alloy electroformed by a roll-to-roll process. NiFe (oxy)hydroxide synthesized by an anodization method for the OER catalyst shows an overpotential of 250 mV at 10 mA cm<SUP>-2</SUP>, which is dramatically smaller than that of bare NiFe alloy with an overpotential of 380 mV at 10 mA cm<SUP>-2</SUP>. Electrodeposited NiMo films for the HER catalyst also exhibit a small overpotential of 100 mV at 10 mA cm<SUP>-2</SUP> compared with that of bare NiFe alloy (550 mV at 10 mA cm<SUP>-2</SUP>). A combined spectroscopic and electrochemical analysis reveals a clear relationship between the surface chemistry of NiFe (oxy)hydroxide and the water splitting properties. These outstanding fully solution-processed catalysts facilitate superb overall water splitting properties due to enlarged active surfaces and highly active catalytic properties. We combined a solution-processed monolithic perovskite/Si tandem solar cell with MAPb(I<SUB>0.85</SUB>Br<SUB>0.15</SUB>)<SUB>3</SUB> for the direct conversion of solar energy into hydrogen energy, leading to the high solar-to-hydrogen efficiency of 17.52%. Based on the cost-effective solution processes, our photovoltaic-electrocatalysis (PV-EC) system has advantages over latest high-performance solar water splitting systems.</P> [FIG OMISSION]</BR>