This study aims to classify types of work-life balance among employees using Latent Profile Analysis (LPA) and investigate variations in depressive symptoms and satisfaction with working conditions across these types. Data were derived from the 6th Korean Working Conditions Survey (KWCS), conducted between 2020 and 2021, which included a sample of 49,479 employed individuals. The LPA revealed three distinct profiles of work-life balance: Low Balance (18.5%), Moderate Balance (72.9%), and High Balance (8.6%). Significant differences in depressive symptoms and satisfaction with working conditions were observed among these profiles. Specifically, the Low Balance group exhibited the highest levels of depressive symptoms and the lowest satisfaction with working conditions, while the High Balance group displayed the lowest depressive symptoms and the highest satisfaction. These findings underscore the critical role of work-life balance in influencing both depressive symptoms and job satisfaction among workers.

The purpose of this study is to investigated occupational accidents of child care worker. We surveyed 392 childcare worker to investigate their experience of occupational accidents. Fifteen percent of the respondents from occupational accdients survey for child care workers reported that they had experienced more than one occupational accident, but mostly did not claim Occupational Safety and Health Insurance. We suggested policy tasks to improve system for protecting child care workers.

강원도농업기술원 옥수수연구소에서 개발된 자색옥수수 색소 1호는 알곡은 노란색인 반면, 알곡을 제거한 속대 와 알곡을 감싸고 있는 포엽에 자색이 발현되는 품종이다. 색소 1호 품종은 포엽과 속대에 안토시아닌 색소가 고 함량으로 집적되는 특징이 있다. 현재 옥수수 포엽은 국내 식품원료로 등록되어 있지 않아 식품원료로 사용할 수 없다. 강원도농업기술원 농식품연구소에서는 자색옥수수 포엽과 속대의 식품활용 범위를 넓히기 위하여 색소 1호 품종의 포엽과 속대 혼합추출물에 대한 독성 및 안전성 평가를 수행하고 식품의약품안전처의 한시적 식품원료 등 록(식품원료 한시기준 제2017-5호)을 추진하였다. 사용대상식품 및 사용량은 100g당 과자 및 액상차 0.51g 이하, 빵 류, 식초 0.17g 이하, 탁주 0.059g 이하로 허용된 범위 내에서 식품원료로 사용 가능하다. 추출물이 적용 가능한 식 품 중 안토시아닌 함유 액상차를 개발하였고 개발된 제품의 저장시험을 통하여 안토시아닌 함량 및 품질 변화를 측정하였다. 저장온도는 25℃, 35℃, 45℃로 설정하였고 총 12주 동안 3주마다 총 안토시아닌 함량 및 당도, pH, 색 도, 대장균수 등을 측정하였다. 실험기간동안 당도 및 pH의 유의적인 변화는 없었으며 대장균은 모든 기간 동안 검출되지 않았다. 총 안토시아닌 함량은 온도가 높을수록 높게 측정되었는데 저장기간이 길어짐에 따른 색차변화 와 연관성이 있으며 총 안토시아닌 측정 시 흡광도에 영향을 주었을 것이라 판단된다. 본 실험결과는 추후 개발되 는 액상차류 제품의 유통기한 및 유통온도, 품질 등을 설정하기 위한 기초자료로 사용하고자 한다.

The purpose of this study was to measure the job aspiration and examine the relationship between that and job satisfaction for wage-earners using the fourth Korean Working Conditions Survey(KWCS). We use the stochastic frontier model for measuring the job aspiration and testing its effect on the job satisfaction. Fstochastic frontier model is introduced to explain that each company potentially produces less than it might due to a degree of job aspiration, measured by decomposing the residuals. In this model framework, it can be regard that the upper bound of the job satisfaction is the ideal frontier, and the bias between the ideal condition and the reality is the job aspiration. If this concept is applicable to the job aspiration, we can measure this bias and investigate a relationship with the job satisfaction. We find that there exists the job aspiration, and it is significantly negatively correlated with the job satisfaction. This result supports that if job aspiration increases, job satisfaction level decreases.

The Purpose of this study is to compare occupational accident rate of unionized and non-unionized company and to investigate influences of labor relations on occupational accident rate in Korean manufacturing and construction Industry. Data in 2011 Occupational safety and Health Trend Survey were analyzed for this study. Results show that the occupational accident rate was lower in unionized company than non-unionized company. And amicable labor relationship reduces the occupational accident rate. The policy should be needed to support labor union and improve labor relationship to prevent industrial accidents.

Graphene oxide has been synthesized by microwave-assisted exfoliation of graphite oxide prepared by modified Hummers method. Graphite was oxidized in a solution of H2O2 and KMnO4 at 65~80˚C, followed by 10 % H2O2 solution treatment at 80~90˚C. The graphite oxide was exfoliated under microwave irradiation of 1 kW and was reduced to graphene effectively by hydrazine hydrate (H4N2·H2O) treatment. The exfoliation of graphene oxide was significantly affected by the microwave irradiation on (heating)/off (cooling) period. An on/off period of 10 s/20 s resulted in much more effective exfoliation than that of 5 s/10 s with the same total treatment time of 10 min. This can be explained by the higher exfoliation temperature of 10 s/20 s. Repetition of the graphite oxidation and exfoliation processes also enhanced the exfoliation of graphene oxide. The thickness of the final graphene products was estimated to be several layers. The D band peaks of the Raman spectra of the final graphene products were quite low, suggesting a high crystal quality.

본 연구는 졸음운전의 지표로 예상되는 심전도의 LF/HF 비율이 효과적으로 졸음운전을 예측하는지를 검증하는 것이었다. 본 연구는 총 31명이 참가하였으며, 가상 운전시뮬레이션 과제를 활용하여 진행하였다. 수면박탈이 운전 중 LF/HF 비율에 영향을 미치는지를 검증하기 위해 충분한 수면을 취한 조건과 수면이 박탈된 조건으로 실험을 실시하였다. 충분한 수면을 취한 조건에서 참가자는 전날 6시간 이상의 수면을 취한 후 30분동안 진행되는 가상 운전과제를 수행하였다. 수면이 박탈된 조건에서는 실험에 참여하기 전날에 참가자가 5시간 이하의 수면을 취하도록 유도한 후 60분 동안 진행되는 가상 운전 과제에 참여하도록 하였다. 참가자는 두 조건 모두에서 심전도를 측정할 수 있는 장비를 착용한 상태로 가상 운전 과제를 수행하였다. LF/HF 비율과 지각된 졸음운전과의 관계성을 확인하기 위해서 참가자가 가상 운전 과제를 수행하는 동안 10분간격으로 주관적 졸림정도를 측정하였다. 실험 결과 충분한 수면을 취한 조건보다 수면박탈 조건에서 참가자의 LF/HF 비율이 감소하였으며, 동일하게 주관적 졸림정도는 증가하였다. 또한 주관적 졸림정도가 LF/HF비율을 예측하는 것으로 나타났다. 따라서 LF/HF 비율을 통한 졸음 운전 예측은 타당한 것으로 나타났다.

연골은 혈관과 신경의 분포가 없이 단단한 세포외 기질로 쌓여있어 손상되거나 퇴화되면 재생이 어려운 조직이다. 연골조직은 다른 결합조직과는 달리 당단백질, 연결조직섬유 및 매트릭스 등의 기질에 의해 유연성을 갖는다. 실크단백질은 천연 단백질로서, 세리신과 피브로인 두 가지 단백질로 되어있다. 실크는 몸속에 삽입할 경우 생체적합성이 뛰어나며 면역 거부반응이 미미하여, 최근 많은 연구자에의해 생체재료로서 새로운 의료용 소재로서 개발되고 있다. 실크단백질은 다양한 아미 노산의 결합으로 이루어져있어, 당단백과 매트릭스로 이루어진 연골조직을 대체 할 수 있을 것으로 생각되었다. 본 연구에서는 실크단백질을 이용하여 연골세포의 성장에 대한 실크의 영향을 세포수준과 분자적 수준에서 관찰하였다. 또한 줄기세 포 배양 시, 실크단백질을 처리하여 줄기세포가 연골세포로 분화되는데 있어 실크 단백질이 분화에 어떤 영향을 미치는지를 확인하였다. 실크단백질은 연골세포의 성장에 효과적이었으며, 연골분화마커인자의 발현량을 증가시켰다. 실크 단백질 은 줄기세포의 연골분화에 도움을 주는 것을 확인할 수 있었다. 따라서 연골세포를 이식하는 치료 시 실크단백질을 우수한 첨가제로서 사용할 수 있을 것으로 기대된다.

Silicon nanoparticle is a promising material for electronic devices, photovoltaics, and biological applications. Here, we synthesize silicon nanoparticles via CO2 laser pyrolysis and study the hydrogen flow effects on the characteristics of silicon nanoparticles using high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and UV-Vis-NIR spectrophotometry. In CO2 laser pyrolysis, used to synthesize the silicon nanoparticles, the wavelength of the CO2 laser matches the absorption cross section of silane. Silane absorbs the CO2 laser energy at a wavelength of 10.6μm. Therefore, the laser excites silane, dissociating it to Si radical. Finally, nucleation and growth of the Si radicals generates various silicon nanoparticle. In addition, researchers can introduce hydrogen gas into silane to control the characteristics of silicon nanoparticles. Changing the hydrogen flow rate affects the nanoparticle size and crystallinity of silicon nanoparticles. Specifically, a high hydrogen flow rate produces small silicon nanoparticles and induces low crystallinity. We attribute these characteristics to the low density of the Si precursor, high hydrogen passivation probability on the surface of the silicon nanoparticles, and low reaction temperature during the synthesis.

The purpose of this study was to examine the effects of stress response on safety behavior and to explore moderating effect of safety climate between stress response and safety behavior. 224 workers were asked to respond to the questionnaires that measured various demographic variables, stress response, safety climates and safety behaviors. A hierarchical regression was conducted to identify variables that had significant relationships with safety behavior and to examine moderating effect of safety climate between stress response and safety behavior. Results indicated that the depression response significantly predicted safety behavior. It was found that the safety climate was also a significant predictor for safety behavior. In addition, safety climate had a moderating effect on the relation between depression and anger responses and safety behavior.

This study compared the effects of praise and punishment for improving safety behaviors. Participants were 30 volunteer undergraduate students and they were randomly assigned to one of two experimental conditions: (1) praise under which positive feedback was delivered for safe behaviors, (2) punishment under which negative feedback was delivered for unsafe behaviors. A simulated computerized work task was developed specifically for this study. Participants had to work on the work task and follow seven safety rules while working. When they follow all the seven safety rules, their behaviors were considered safe. If they did not follow any one of the rules, their behaviors were considered unsafe. Results showed that the percentage of safe behavior under group of praise feedback was significantly higher than under group of punish feedback.