• 한국안전학회지
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• 제23권5호
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• pp.119-124
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• 2008

Many automobile assembly workers often do several cycles of tasks continuously, i.e., without breaks, to get a longer break. This is not recommended since the dose of fatigue increases exponetially with time and it takes much longer time to recover. In this study, a laboratory experiment was conducted to investigate the effect of work/rest schedules on workload of a repetitive upper-limb task. Eleven male subjects participated in the experiment, in which simulated screw driving tasks were carried out repetitively with 3 different work/rest schedules: standard breaks(1 cycle of work at a time, 60 20-s breaks), medium breaks(5 cycles of work at a time, 12 100-s breaks), and long breaks(10 cycles of work at a time, 6 200-s breaks). The result showed that medium- and long-breaks schedules significantly increased the level of perceived discomfort and %HRR as compared to the standard-break schedule. The subjects' preference was not statistically different among work/rest schedules, which might be caused from the absolutely low level of workload of the experimental tasks. From the results, it is recommended to have frequent and shorter breaks rather than infrequent and longer breaks to decrease the level of physical workload. A more expanded studies, however, should be carried out to provide more practical safety guidelines on the work practice of continuous working without breaks among automobile assembly workers.

• 한국전기전자재료학회논문지
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• 제33권6호
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• pp.445-449
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• 2020

Non-volatile memory is approaching its fundamental limits with the Si₃N₄ storage layer, necessitating the use of alternative materials to achieve a higher programming/erasing speed, larger storage window, and better data retention at lower operating voltage. This limitation has restricted the development of the charge-trap memory, but can be addressed by using high-k dielectrics. The paper reviews the doping of nitrogen, titanium, and yttrium on high-k dielectrics as a storage layer by comparing MONOS devices with different storage layers. The results show that nitrogen doping increases the storage window of the Gd₂O₃ storage layer and improves its charge retention. Titanium doping can increase the charge capture rate of HfO₂ storage layer. Yttrium doping increases the storage window of the BaTiO₃ storage layer and improves its fatigue characteristics. Parameters such as the dielectric constant, leakage current, and speed of the memory device can be controlled by maintaining a suitable amount of external impurities in the device.

• 한국재료학회지
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• 제11권2호
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• pp.151-154
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• 2001

상부전극, Pt, Ir, 그리고 $IrO_2$, 에 따라 수소 열처리전과 후, 그리고 회복열처리시 누설전류특성을 고찰하였다. Pt/PLZT/Pt 케페시터는 수소열처리 후에 다시 회복열처리를 수행하면 완전히 이력곡선의 회복을 보이며 또한 피로특성도 거의 회복 된다. Pt과 IrO$_2$ 상부전극의 경우의 진 누설전류 특성은 열처리조건에 관계없이 강한 시간 의존성을 갖는 space-charge influenced injection모델에 적합하다. 반면에 Ir 상부전극의 경우는 Ir과 PLZT 사이의 계면에 헝성된 전도성 상인 $IrO_2$로 인해 높은 누설전류 밀도를 보이면서 relaxation current 영역이 없이 steady state 영역을 보이는, 주로 Schottky barrier 모델에 의해 설명된다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.637-640
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• 2005

The mechanical properties of bellows, such as the extensibility and the strength can be changed depending on the shape. For the shipbuilding material, it is favorable that the fatigue lift is long due to the elastic property and the reduction of thermal stress in piping system. Nowadays, the domestic production and design of bellows are based on the E.J.M.A Code. Therefore, the design standard is in need because of much errors and lack of detailed analysis. In this study, it is attempted to find out the optimal shape of U-type ship's bellows that is applied to design of experiment using the finite element method. The effective factors, mountain height, length, thickness, and number of mountains and the length of joint are considered and the proper values are chosen for the simulation. The number of mountains are increased, the volume increases above the standard volume and the stress obviously increases. In addition, the effect of the thickness of bellows on the stress is very large. Both of the volume and stress are decreasing at a certain lower value region.

• Gut and Liver
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• 제12권6호
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• pp.694-703
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• 2018

Background/Aims: Limited data exist comparing the safety and efficacy of direct-acting antivirals (DAAs) in hepatitis C virus (HCV) monoinfected and HCV/human immunodeficiency virus (HIV) coinfected patients in the real-world clinic practice setting. Methods: All HCV monoinfected and HCV/HIV coinfected patients treated with DAAs between January 2014 and October 2017 in community clinic settings were retrospectively analyzed. Pretreatment baseline patient characteristics, treatment efficacy, factors affecting sustained virologic response at 12 weeks (SVR12) after treatment, and adverse reactions were compared between the groups. Results: A total of 327 patients were included in the study, of which 253 were HCV monoinfected, and 74 were HCV/HIV coinfected. There was a statistically significant difference observed in SVR12 when comparing HCV monoinfection and HCV/HIV coinfection (94% and 84%, respectively, p=0.005). However, there were no significant factors identified as a predictor of a reduced response. The most common adverse effect was fatigue (27%). No significant drug interaction was observed between DAA and antiretroviral therapy. None of the patients discontinued the treatment due to adverse events. Conclusions: In a real-world setting, DAA regimens have lower SVR12 in HCV/HIV coinfection than in HCV monoinfection. Further studies involving a higher number of HCV/HIV coinfected patients are needed to identify real predictors of a reduced response.

• 대한한방내과학회지
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• 제40권5호
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• pp.797-803
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• 2019

Introduction: The aim of this study was to report the effect of Korean medicine treatments on a stroke patient with homonymous hemianopsia. Case Presentation: A 50-year-old male with a posterior cerebral artery infarction had continuously deteriorating symptoms of right homonymous hemianopsia, fatigue, dizziness, and light sensitivity. Treatment with Korean medicine therapy, including acupuncture and herbal medicine significantly improved the patient's symptoms. The result of a visual field test (VFI) was also improved after treatment, and no side effects were observed during treatment. Conclusion: Korean medicine treatment can be considered an effective treatment for homonymous hemianopsia in stroke patients.

• 한국추진공학회지
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• 제14권4호
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• pp.39-45
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• 2010

자주포 또는 원자로와 같은 두꺼운 실린더는 압력용기 내부에 유익한 잔류 압축응력을 유도하여 작용압력과 피로수명을 증가시키도록 자긴 가공되고 있다. 자긴가공도가 증가하면 구멍에서 압축잔류응력의 크기도 증가한다. 본연구의 목적은 ASME 코드에 의해 적용된 Kendall 모델을 이용하여 고강도 SCM440 강의 정확한 잔류응력을 예측하는 것이다. SCM440 후육실린더의 내부에 유압이 적용되고 30% 변형률까지 자긴 가공하였다. 자긴가공된 시편은 전해연마하고 X-ray 회절법을 이용하여 정확한 잔류응력을 산출하도록 하였다. 그리고 주사전자현미경을 이용하여 자긴가공에 의해 소성변형된 표면층을 분석하였다. 측정한 잔류응력과 계산된 결과를 비교하여 약간의 차이는 있으나 비교적 서로 잘 일치하고 있다.

• 한국철도학회논문집
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• 제10권5호
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• pp.540-545
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• 2007

틸팅 열차는 곡선 구간에서 차체가 안쪽으로 기울어져 고속으로 회전해도 탈선하지 않는 열차를 말한다. 여러해 동안 한국철도기술연구원에서는 이 열차를 개발해왔다. 이 논문에서는 그동안 개발되어온 틸팅 열차의 동역학해석을 수행하였다. 이를 통해서 국제기준에 맞는 안정성과 주행성능을 지니고 있는지 확인하고 향후 속도 개선의 기본 자료를 생성하였다.

• 한국학교ㆍ지역보건교육학회지
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• 제15권3호
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• pp.55-65
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• 2014

Objectives: This study aims to develop a decent sallimyok program and provide basic data which are helpful in improving psychological wellbeing for adults who are exposed to stress and fatigue. Methods: Middle-aged women living in Cheongju, Chungbuk were divided into experimental and control groups (10 people each) through convenience sampling, and a questionnaire survey on psychological wellbeing was distributed to them and collected. For data analysis, IBM/SPSS 20.0 was used. In terms of statistical analysis, a reliability test (Cronbach's ${\alpha}$) was conducted. To test research questions 1 and 2, independent t-test and paired sample t-test were carried out. Results: First, a sallimyok program features meditation (floor-sitting, slow walk), forest therapy, stretching exercise, wrapping-up and sharing feelings. Second, it was confirmed that a sallimyok program has a positive effect on the improvement of psychological wellbeing and the depression for women. Conclusions: The sallimyok program improved participants' psychological wellbeing, which means that it could reduce their anxiety and stress.

• 방송공학회논문지
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• 제26권5호
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• pp.643-651
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• 2021

현대인들의 정보습득은 대부분 시각을 통해 이루어진다. 컴퓨터, 스마트폰 등의 스크린은 사람들의 시각을 끊임없이 자극하여 피로감을 증가시킨다. 이러한 사회 현상 속에서 21세기의 최첨단 사운드 시스템의 실감 나고 풍부한 소리는 사람들의 몸과 마음에 다양한 방법으로 영향을 미칠 수 있다. 소리를 통해 인간은 마음을 안정시키고 자신을 관찰할 여지를 제공받게 되는 것이다. 본 논문에서는 ALgruppe와 Rory's PranaLab이 공동으로 실시한 실감음향을 기반으로 한 입체음향요가 수련을 소개하고 실감오디오 시스템에 관한 이해를 도모하고자 하는 목적을 가진다. 실감음향으로 체험하는 입체음향 요가는 단순히 소리의 효과를 누리는 것이 아니라 요가 수련자들이 내면을 들여다보는 자의식을 갖게 하는 강력한 에너지가 됨을 알 수 있었다. 이는 현대사회의 지식의 지평이 요구하는 다학문적 교류에 대한 응답임과 동시에 새로운 문화콘텐츠의 가능성을 알리는 것이다.