• 한국산업보건학회지
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• 제26권4호
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• pp.426-435
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• 2016

Objectives: The major objective of this study was to analyze stress response after a change to consecutive day shifts from day and night shifts in a motor assembly factory. Methods: Using a survey conducted by a labor union, we collected data on stress response index(SRI), lifestyle factors, work-family conflict and job stress before and after a shift system change. We analyzed the transition on the SRI among 222 workers. The cut-off point for the SRI was a T-score over 60. Results: The high risk stress response group was 20.3% of the population before the shift system change. After the shift system change it decreased to 11.3%. After the shift system change, social support improved, leisure time became more sufficient, work-family conflict declined, and sleep quality in the night shift week improved. In multivariable linear regression, among workers under 40 years old sleep quality on night shift, leisure time sufficiency, social support and work-family conflict contributed to the improvement of stress response. Among workers over 40, work-family conflict contributed to the improvement of stress response. Conclusions: The change to consecutive day shifts improved stress response and mediated with improved nighttime sleep, decreased work-family conflict, increased leisure time and improved work-family conflict.

• 한국가정과학회지
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• 제4권1호
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• pp.93-107
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• 2001

The purpose of this study was examine the health and food intakes of industrial workers who worked day and night. The questionnaire asked them about their health, stress, knowledge of nutrition, food habits, food intakes and frequency. The night-time workers had a stomachache compaired with day-time workers. Male day-time workers were more prone to stress than night-time workers in the area of job. In the areas of nutritional knowledge and food habits, there were no significant differences between day-and night-time workers for both male and female. Intakes of rice, bread, noddle, meat, fish. beans, vegetables in night-time workers were less than day-time workers. Also the male night-time workers consumed more milk and carbonated drinks than the day-time workers. The night-time workers were worse than the day-time workers and the female night-time workers were the worst. Considering the above results, the night-time workers should correct their food habits and have a well-balanced diet.

• 유통과학연구
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• 제14권5호
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• pp.91-96
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• 2016

Purpose - Although various studies have been conducted on the stress of service employees, there are still lack of studies regarding job stress and job satisfaction of call center workers. Especially there are quite few studies on the job stress according to employment type. This study focused on job stress and job satisfaction for call center employees and the correlation between the two factors and aimed to provide basic materials for seeking for the plans to reduce job stress and improve job satisfaction. Research design, data, and methodology - Frequency, percentage, and mean value were calculated through descriptive statistics in order to find out demographic characteristics, level of job stress, and job satisfaction. Differences in job stress according to employment type were calculated by using one-way ANOVA. Correlation between job stress and job satisfaction were identified through empirical analysis with Pearson's correlation coefficient. 150 materials were used for final analysis. The collected materials were analyzed to get statistics by using SPSS 20. Results - First, as for the job stress of call center workers, overall mean value was 2.54 in 4-point scales. Among the six sub-factors, job demands had the highest score, which was 2.67. Second, as for the job stress according to employment type, others showed higher score than mean value followed by contract job and full-time job in that order, in terms of job insecurity and organizational system. In terms of inappropriate remuneration, contract job showed higher score than mean value followed by others and full-time job. Third, as for the satisfaction with job, the mean value was 2.37 in 4-point scale and "very much satisfied" was only 3.3%. Lastly, in terms of job stress and job satisfaction, all sub-factors except for job demands showed significant correlation. The more job stress increased, the more job satisfaction decreased. Conclusions - First, as a result of analyzing job stress according to the employment type of call center workers, job stress increased more when the employment type was not full-time. Therefore, it was assumed that self-rescue efforts should be followed for effective employment management of call center business where contract employment takes most part as well as efforts to transfer them to full-time job. Second, decrease in job satisfaction of call center workers may affect the performance of an organization as well as service quality of the company providing the service. Therefore, various supports are required to decrease job stress and increase job satisfaction for call center workers through the expansion of rest area or break time. Third, I could recognize that there were lack of academic research on call center business in the whole service industry. Therefore, further research should be conducted more actively in the future. In particular, this study has special significance in the aspect that there were few studies on the job stress of call center workers according to employment type.

• 인터넷정보학회논문지
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• 제19권4호
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• pp.95-105
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• 2018

As the IT industry has developed, the frequency of mobile communication usage has increased sharply. Mobile communication has many advantages such as improving work performance, communication beyond time and local constraints, and rapid and vast amounts of information exchange. However, mobile communication also allows supervisors to give their subordinates work at any time. Thus, mobile communication may also have a negative impact on workers' stress levels during non-work time. This study examined required time, urgent business, personal engagement, and trivial matters as sub-dimensions of mobile communication messages that workers could receive during non-work time. Further, the nature of the relationship between team leaders and members explains how these messages may increase the stress levels of workers. Supervisors should prohibit the use of such mobile communication, and efforts should be made at the enterprise level. Through this research, we aim to explain the dual nature of mobile communication, and understand how to optimize the usage of this innovative technology

• 대한기계학회논문집
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• 제14권1호
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• pp.130-137
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• 1990

본 연구에서는 Bueckner의 가중함수법을 열충격 문제에 도입하여 열충격 응력 세기계수를 구하고, 평면변형을 파괴인성치와 비교하여 재료가 열충격을 받은 후 파괴 되는 시간을 이론적으로 계산한다. 또한 음향 방출법을 이용하여 파괴시간을 측정하 고 이론치와 비교한다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.408-411
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• 2004

The electrical stability against surge stress of ZPCCY-based varistors were investigated at different sintering times. Sintering time decreased the varistor voltage and nonlinear exponent from 279.6 to 179.1 and from 52.5 to 24.9, respectively. On the contrary, the leakage current and dielectric dissipation factor increased from 1.2 to 9.8 ${\mu}A$ and from 0.0461 to 0.0651 with increase of sintering time. For all varistors, the variation rates of V-I characteristic parameters against surge stress were affected in order of varistor voltage$\rightarrow$nonlnear exponent$\rightarrow$leakage current. On the whole, the electrical stability against surge stress increased with increasing sintering time. Conclusively, it is assumed that the varistor sintered for 2 h exhibited comparatively good characteristics, in view of overall characteristics.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.368-368
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• 2010

Using TFTs crystallized by MICC and ELA, electron mobility and threshold voltage were measured according to various substrate temperature from $-40^{\circ}C$ to $100^{\circ}C$. Basic curve, $V_G-I_D$, is also measured under various stress time from 1s to 10000s. Consequently, due to the passivation effect and number of grains, mobility of MICC is varied in the range of -8% ~ 7.6%, while that of ELA is varied from -11.04% ~ 13.25%. Also, since $V_G-I_D$ curve is dominantly affected by grain size, active layer interface, the graph remained steady under the various gate bias stress time from 1s to 10000s. This proves the point that MICC can be alternative technic to ELA.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.702-707
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• 2000

Under the rapid change of a new vehicle model, it is necessary to develop a durability analysis technique using computer simulation. In order to do this. reliable dynamic stress-time history for the vehicle components must be calculated on various road conditions. In this paper, a full vehicle simulation model which is composed of flexible frame and chassis components is proposed and verified its reliability from the comparison with field test data. Finally, dynamic stress-time history on the rear chassis components is predicted with hybrid and modal superposition method.

• 대한기계학회논문집A
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• 제21권4호
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• pp.673-678
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• 1997

Stress wave propagations in an elastic half space to a normal point force of ramp type in time are analyzed. The governing equations are transformed by applying the Laplace and Hankel transforms with respect to time and radial distance. The inversion of Laplace transforms are performed by employing the Cagniard-de Hoop method, where the Rayleigh waves at surface are obtained by including the residue terms. The stress waves computed at the location very cose to the surface are shown to be almost identical to the surface waves obtained by the residue method except the Rayleigh wavefront. It is found that at the surface, the stresses are dominated by the Rayleigh waves, whose amplitudes increase linearly with time when time is very large. It is also found that in the interior part, the radial stress has a logarithmic singularity at the shear wavefront, while tangential stress shows no singularity.

• 한국기계가공학회지
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• 제7권2호
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• pp.66-71
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• 2008

The data of the deformation and the stress according to time are studied at upper model of press and lower model of the blanking plate applied by press with the width, length and height of 0.4 m and 0.6 m respectively. The press is pushing downward on the plate fixed at the lower floor. These data are compared and investigated through this study. By using these results, there is the maximum deformation at 4 corners in the lower plate model of aluminium alloy fixed at lower floor. This deformation incase of elapsed time of 0.6 second becomes 4 times as much as in case of elapsed time of 0.2 second. The quantity of deformation at the lower plate model becomes more than at the upper press model to the extent of 10%. At the lower plate model of aluminium alloy, there is the maximum Von-Mises equivalent stress at 4 corners and both sides of middle area on the lower plate model of aluminium alloy. This stress in case of elapsed time of 0.6 second becomes 6 times as much as in case of elapsed time of 0.2 second. The Von-Mises equivalent stress of lower plate model becomes 2 times as much as that of upper press mode.