Hydrogen infrastructure, for instance, such as hydrogen stations, supply chain network, is important in society of hydrogen economy. Special alloy are frequently used to prevent the hydrogen embrittlement in hydrogen vehicles, semiconductor factories and so on. Because special alloy including Monel material has high strength and high hardness, it is known as the hard-to-cut or roll material. This paper aims to investigate the characteristics and safety on bearing and shaft, which consist of key parts of rolling unit, through structural analysis. As the results, it showed that the bearing was weaker than shaft. Further the bearing was safe up to 20.4 ton, which was about 2 times of maximum of roller reaction force in case of considering as static load. However, the bearing was safe up to 10.2 ton in case of considering as repeated load.

The purpose of this study was to breed a variety of stable productivity and high storage characteristics of white Hypsizygus marmoreus, which has high demand at domestic and global market due to a low bitter taste and the preference for white species. Accordingly, ‘Baekmaru’ was bred by hybridizing brown and white cap color species and backcrossing with white species. The ‘Baekmaru’ variety was bred by crossbreeding the brown and white species and backcrossing the white species. Through repeated cultivation of ‘Baekmaru’, a variety with a low contamination rate was selected when culturing the spawn for stable cultivation. As a results of demonstration test, the yield of ‘Baekmaru’ was 14% higher than that of the commercial variety. In addition, among the fruiting body characteristics of ‘Baekmaru’, diameter and thickness of the pileus were 16.43±15.27mm and 6.46±0.58mm, which were slightly higher than the commercial variety, and the hardness was 2.69±0.89N for the pileus and 3.09±0.89N for the stipe. The shelf life showed less change in thickness and color of pileus compared to commercial variety. The hardness of pileus of 'Baekmaru' was maintained in the range of 3.5 to 4.0N in the 4oC and 4oC and 20oC mixed treatment until 30 days of storage, and was higher than that of the commercial variety. Therefore, it was suggested to be excellent in storability.

본 연구의 목적은 좌우 방향의 회전 후 직립자세 시 압력중심과 근전도 분석을 토대로 회전선호 도가 신체 안정성에 미치는 영향을 알아보고자 하였다. 연구의 대상은 오른쪽 손과 발의 편측선호도가 높 은 대상자 16명으로 3가지 회전방향 조건(QS: 직립자세, LT: 왼쪽 10바퀴, RT: 오른쪽 10바퀴)을 수행하 였다. 회전 후 직립자세 시 안정성을 평가하기 위하여 압력측정판과 근전도를 이용하여 결과를 도출하여 분석하였다. 연구결과로 모든 압력중심 변인은 QS보다 LT, RT가 크게 나타났지만, 회전방향에 따른 차이 는 보이지 않았다. 근전도 결과는 좌우 비복근에서 회전방향에 따라 RT가 QS보다 근활성도가 크게 발생 되었다. 결론적으로 대상자가 모두 오른쪽 측면선호도가 높았지만 압력중심에서는 회전선호도의 영향이 없 었고, 비복근에서는 회전선호도의 영향이 나타났다.

This paper is about structural, and vibration analysis for the development of Index chucks Structural and vibration analyses were performed using the ANSYS Mechanical program to evaluate the Index chuck's structural stability and vibration characteristics. As a analysis result, when the maximum load of 500N was applied to the Index chuck, the safety factors were 2.06, 2.09, and 2.60, respectively, when the thickness was 5mm, and the outer diameters were 70mm, 90mm, and 120mm, respectively. Structurally safe results were obtained. In addition, under load conditions of 300 N or less, structural safety was confirmed if the thickness is 3mm or more.

This research studied faults that may occur during slow charging using the J1772 adapter of Tesla Model-3 electric vehicles. When the AC terminal was instantaneously disconnected, charging was performed normally when an AC circuit with disconnection up to three disconnection times was connected. Charging control was suspended when the number of disconnection reached four times. However, if the AC disconnection time exceeded 22 seconds, the charging control was stopped regardless of the number of disconnection. When a contact failure occurred at the AC terminal, high surge current and noise occurred. However, when the contact improved, the charging control continued. In terms of safety, it seems necessary to take measures such as stopping charging control when detecting noise.

Since the competitive environment, it has become common for firms to reduce its workforce to diminish operating cost. Accordingly, job insecurity among employees has been increasing. Previous works on job insecurity have not paid adequate attention to the influence of job insecurity on safety behavior. The current paper investigates the impact of job insecurity on safety behavior and its intermediating mechanisms. In specific, this paper delves into the mediating effect of job stress, as well as the moderating effect of servant leadership in the association between job insecurity and job stress. The results demonstrated that that job insecurity has a positive (+) influence on job stress, which has a negative (-) influence on safety behavior. Moreover, job stress mediated the association between job insecurity and safety behavior. Furthermore, servant leadership moderated the job insecurity-safety behavior link.

본 연구는 다양한 상대습도(11~93%) 조건에서 해조류의 미생물 안정성 및 품질특성에 미치는 영향을 조사하였다. 미생물 안정성은 저장 중 대장균군, 일반세균, 효모 및 곰팡이수를 분석하였다. 일반세균은 상대습도 69~93%에서 4.40~7.00 log CFU/g, 효모 및 곰팡이는 4.20~6.40 log CFU/g로 상대습도 69%이상 조건에서 일반세균, 효모 및 곰팡이의 수가 급격하게 증가하였다. 고결현상은 상대습도 11~53% 조건에서는 일어나지 않았으나 69, 81, 93% 조건에서는 각각 86.9, 99.45, 99.98%로 높은 고결현상을 가지는 것으로 나타났다. 색도는 상대습도가 높아질수록 L값과 b값이 감소하였고, a값이 증가하여 갈변현상이 일어났다. 또한, 총 페놀함량(9.10~8.66 mg GAE/100 g dw), ABTS 소거능(24.20~24.18 mg AAE/100 g dw), FRAP(15.34~15.33 mg Fe(II)/100 g dw)활성은 저장 중 상대습도 11~33%에서 가장 높게 유지되었다. 그러나, 상대습도 43~93%에서 저장 중 총 페놀함량(8.66~4.00 mg GAE/100 g dw), ABTS(22.57~4.50 mg AAE/100 g dw), FRAP(13.06~4.00 mg AAE/100 g dw)활성이 감소하는 것으로 나타났다. 상대습도 81% 조건에서 ABTS 및 FRAP이 1/3배로 감소하였고, 93% 조건에서 총 페놀함량, ABTS 및 FRAP이 각각 1/2배, 1/5배, 1/3배로 감소하였다. 따라서, 일반세균, 효모 및 곰팡이의 성장 억제, 고결현상 방지, 갈변억제, 높은 총 페놀함량과 항산화활성 유지를 위해서는 상대습도 53% 이하의 조건에서 보관하는 것이 미생물 안정성 및 품질특성 유지에 효과적일 것으로 판단된다.

Background: Gluteus medius muscle is important for the stability of hip joint. The sufficient core stability can be contributed to the performance of gluteus medius muscle in standing position. In addition, the external support may affect core stability in standing position. Objects: The purpose of this study was to investigated the effectiveness of the external support on the strength and muscle activity of hip abductor muscle during hip abduction in standing position in subjects without core stability. Methods: Fifteen subjects participated in this study. The subjects were evaluated by using the double-leg lowering with bent knees to measure the core stability. The strength and muscle activity of hip abductors was measured in standing position with the condition with and without external support using the tensiometer sensor and the surface electromyography. The paired t-test was used to investigate the difference between hip abductor strength and activity according to external support. The level of statistical significance was set at α = 0.05. Results: The hip abductor strength and muscle activity of gluteus medius muscle with external support were significantly greater than those without external support during hip abduction in standing position (p < 0.05). Conclusion: During hip abduction in standing position, the external support may be contributed to the improvement of the hip abductor strength and muscle activity of gluteus medius especially in the subjects without core stability.

소변검사 전 냉/해동 반복과 해동 과정에 따라 대표적인 임상 화학검사 측정값의 변화를 확인 함으로써 소변검사의 안정성과 품질 개선방안을 모색하고자 하였다. 조사 대상자는 모두 건강한 남성 10명이었으며 이들의 소변 검체를 이용하여 냉/해동 안정성(freeze and thaw stability) 실험을 진행하였다. Micro-albumin과 Amylase의 경우 시간이 경과 됨에 따라 37℃에서 는 통계적 유의성은 없었으나, 42℃와 60℃에서는 시간의 경과에 따른 결과가 통계적으로 유의한 변동 이 있었고, BUN, Creatinine, Uric acid와 Glucose에서는 통계적으로 유의한 변동이 있었다. Long term의 안정성 결과, 7일이 지난 후에는 Glucose의 변이는 증가하였고, 60℃에서는 Amylase가 감 소하는 양상을 보였다. Glucose와 Amylase의 경우 시간의 경과에 따른 결과가 통계적으로 유의한 변동 이 있었다. 신뢰성 있는 검사결과를 얻기 위해서는 소변 시료의 채취, 보관 및 저장 등을 비롯한 요검사 의 정확한 표준화가 필요하며 생체 물질별 안정성 확보를 위한 조건들의 체계적 연구가 필요하다.

Purpose: 본 연구의 목적은 본 연구의 목적은 2주간의 회전근개의 강화운동이 회전근개의 근육 두께, 견봉하 공간, 어깨 불안정성에 미치는 영향을 알아보고자 하는 것이다. Methods: 근골격계 질환이 없는 대상자 35명을 대상으로 수행하였으며, 횡격막 호흡을 하는 그룹과 횡격막 호흡을 하지 않는 그룹으로 나누었으며, 두 그룹 모두 필라테스를 수행하였다. 실험에 사용한 기기로는 Ultrasonography(US), Pulmonary function tests(FEV1 / FVC), Bioeletic Impedance Analysis, Sit and reach test를 사용하였다. 근골격계 질환이 없는 대상자 20명이 실험에 참여하였다. 근력 강화 운동은 2주 동안 주 5세트, 총 50세트 실시하였으며, 운동은 풀캔, 빈캔, 외회전 운동으로 진행하였다. 초음파를 이용하여 극상근과 극하근의 근육 두께와 견봉하 공간의 변화를 확인하였다. CSMI는 가시위근과 가시아래근의 근력을 평가하는 데 사용되었다. 정규성 검증을 실시한 후, 반복측정분산분석 (repeated measures of ANOVA)를 사용하여 운동 전, 1주후, 2주후를 비교하였다. 사후 분석을 위해 Fisher’s LSD를 실시하였다. Results: 근력의 비교에서 운동 2주 후 측정 시 내회전에서 유의한 차이가 있었다 (P <0.05). 외회전에서는 유의한 차이가 없었다 (P >0.05). 근육두께에서는 가시위근과 가시아래근의 근육 두께는 유의한 차이가 없었다 (P >0.05). 또한 봉우리밑 공간에서도 유의한 차이가 없었다 (P >0.05). Conlusion: 결론적으로, 빈캔 운동과 풀캔 운동, 측면 외회전 운동은 어깨관절 안쪽돌림의 근력 강화에 긍정적인 효과가 있었다

Damages by jellyfish are occurring frequently around the world. Among them, accidents caused by jellyfish stings are serious enough to cause death. So we designed a jellyfish blocking net and analyzed its stability to prevent sting caused by jellyfish entering the beach. To this end, the dynamic behavior of the jellyfish blocking net according to the current speed (0.25-1.0 m/s) and the net type (50, 100 and 150 mm) on the upper part of the blocking net was modeled using the mass spring model. As a result of simulations for the model, the horizontal tension (horizontal component of the mooring tension) of the mooring line increased with the decrease in the mesh size on the upper part of the blocking net at all current speeds, but exceeded the holding force at high tides faster than 0.5 m/s and exceeded the holding force at all current speeds at low tide. Therefore, the jellyfish blocking nets showed poor stability overall. The depth of the float line had a little difference according to the upper mesh size and increased lineary proportional to the current speed. However, the float line sank too much to block the incoming jellyfish. These analysis results helped us find ways to improve the stability of the jellyfish blocking net, such as adjusting the length of the mooring line and improving the holding power. Therefore, it is expected that this technology will be applied us various underwater structures to discover the weaknesses of the structures and contribute to increasing the stability in the future.