• 한국식품조리과학회지
• /
• 제8권1호
• /
• pp.31-41
• /
• 1992

This study has made use of the work sampling for work analysis and productivity of food service institutions centering on 3 general hospitals of 400∼600 beds and centralized service system in Seoul. The results were as flollows; 1. In the mean work percent of dietitians: The indirect work functions marked the highest, as it was 22.0% for the direct work functions, 57.4% for the indirect work functions and 20.6% for the delays. Among the indirect work functions, the decreasing order was original clerical (38.1%), instruction or teaching (8.5%), conference or interview (8.5%), and appraisal (2.3%). 2. In the mean work percent of clerical personnels: The direct work functions (67.2%) marked the highest. Among those, routine clerical was 64.3%, and receiving was 2.8%. 3. In the mean work percent of workers: The direct work functions (77.4%) marked the highest. Among those, the decreasing order was service (24.7%), cooking (22.5%), cleaning (18.2%), and transportation (10.3%). 4. Work percent per labor hour: Dietitians usually continued to work even during the lunch time. In case of clerical personnel working in turn, work percent was high even during the lunch time, however in the other case, it was very low. It was shown that the workers had lunch and break time after every their service. 5. The number of meals served per labor hour were 6.3 meals, and labor time spent per served meal 9.8 minutes.

• 한국의류산업학회지
• /
• 제13권2호
• /
• pp.269-278
• /
• 2011

This study aims at setting up productive capacity which can be usefully utilized for work management of apparel manufacturers. So as to achieve this goal, an apparel manufacturing company which has been operated by miniline system in Seoul was selected. Standard time and man-hour were calculated to create the accurate productive capacity by observing and measuring a work flow included cutting, sewing and finishing processes. And the result is as following. The standard time for each process was presented as cutting process 47004.5s, sewing process 671050.5s and finishing process 22426.3s. And 15284.4ms was computed as total procession man-hour per day of the manufacturer which is organized of 16 people. Also, the procession man-hour for each process was revealed as cutting process 396.7ms(2.6%), sewing process 14509.3ms(94.9%) and finishing process 378.5ms(2.5%). +Surplus was found in the productivity for each process included the cutting process(outshell, lining and seam process), the sewing process(preparation and arrangement process) and the finishing process. But, additional man-hour 52436.18ms was required because the productive capacity was calculated as -surplus(-13.9%) in the sewing process(part and assembly process). Therefore, a work schedule was planned based on the previous result. However, loading can be ideal when a capacity and a load become '0'. The object company should find the way to reduce allowance(26.25%) of the sewing process through reconstruction of consciousness and improvement in functions with analyzing works of operators. Also, they need to consider an additional supplement of the personnel.

• Safety and Health at Work
• /
• 제6권3호
• /
• pp.240-248
• /
• 2015

Background: Recovery from fatigue is important in maintaining night workers' health. This study compared the course of self-reported recovery after 2-week 12-hour schedules consisting of either night shifts or swing shifts (i.e., 7 night shifts followed by 7 day shifts) to such schedules consisting of only day work. Methods: Sixty-one male offshore employees-20 night workers, 16 swing shift workers, and 25 day workers-rated six questions on fatigue (sleep quality, feeling rested, physical and mental fatigue, and energy levels; scale 1-11) for 14 days after an offshore tour. After the two night-work schedules, differences on the $1^{st}$ day (main effects) and differences during the follow-up (interaction effects) were compared to day work with generalized estimating equations analysis. Results: After adjustment for confounders, significant main effects were found for sleep quality for night workers (1.41, 95% confidence interval 1.05-1.89) and swing shift workers (1.42, 95% confidence interval 1.03-1.94) when compared to day workers; their interaction terms were not statistically significant. For the remaining fatigue outcomes, no statistically significant main or interaction effects were found. Conclusion: After 2-week 12-hour night and swing shifts, only the course for sleep quality differed from that of day work. Sleep quality was poorer for night and swing shift workers on the $1^{st}$ day off and remained poorer for the 14-day follow-up. This showed that while working at night had no effect on feeling rested, tiredness, and energy levels, it had a relatively long-lasting effect on sleep quality.

• 환경위생공학
• /
• 제21권4호
• /
• pp.19-28
• /
• 2006

The purpose of this study was to investigate the related factor for the prevalence of musculoskeletal symptoms among 212 sewing worker. The survey was performed with self-administered questionnaire for the risk factors related to musculoskeletal disorders(MSDs) from August 5 to 7 in 2005. The prevalence of musculoskeletal symptoms were 75.8% and the those of the local symptoms were 71.7 % for shoulder, 60.4 % for neck, 35.8 % for arm and 50.9 % for wrist. The risk factors related the self-reported MSDs had not shown in general characteristics. But, there was a significant difference between daily working hour and wrist, working speed and neck, the degree of satisfaction and wrist for work related factor. Also, it was shown the significant difference between chair height and neck, the height of sewing machine and wrist among the space below work station, neck, waist for the prevalence of musculoskeletal symptoms. The significant correlation was shown for daily working hour and wrist, working speed and arm, work load and shoulder and the degree of satisfaction and arm for work related subjective symptom. Considering above results, it is suggested the ergonomic design be provided to working hour, the height of chair and work station as well as daily working hour even there is a significant difference for the prevalence of symptoms in each body part for sewing workers.

• Journal of Biosystems Engineering
• /
• 제34권6호
• /
• pp.425-433
• /
• 2009

The developed final shattering machine for labor-saving mechanization of shattering of sesame consisted of input part, shattering part, re-shattering part for unshattered pod and pneumatic sorter. The bundle of sesame was held as upside down and fed into the machine continuously. Then, the fed bundle of sesame was shattered by side shock and agitation. The performance of shattering for the sun dried bundle of sesame of conventional manual work and final shattering machine was compared. Since the shattering ratio measured by the final machine was 97.2% at the first operation, in case of fully dried sesame by drying stand, the harvest of sesame can be completed by only one time shattering operation. The work hour per area of 10 a for the mechanical work and the manual work were 0.3 hour and 13.9 hour, respectively. The total shattering ratio of the final machine with vertical feedings of bundle of sesames was 97.2%.

• Safety and Health at Work
• /
• 제8권2호
• /
• pp.212-219
• /
• 2017

Background: Low back pain (LBP) is a major problem for office workers. Individuals adopting poor postures during prolonged sitting have a considerably increased risk of experiencing LBP. This study aimed to investigate seat pressure distribution characteristics, i.e., average pressure, peak pressure ratio, frequency of postural shift, and body perceived discomfort (BPD), during 1 hour of sitting among office workers with and without chronic LBP. Methods: Forty-six participants (chronic LBP = 23, control = 23) typed a standardized text passage at a computer work station for an hour. A seat pressure mat device was used to collect the seat pressure distribution data. Body discomfort was assessed using the Body Perceived Discomfort scale. Results: Office workers with chronic LBP sat significantly more asymmetrically than their healthy counterparts. During 1-hour sitting, all workers appeared to assume slumped sitting postures after 20 minutes of sitting. Healthy workers had significantly more frequent postural shifts than chronic LBP workers during prolonged sitting. Conclusion: Different sitting characteristics between healthy and chronic LBP participants during 1 hour of sitting were found, including symmetry of sitting posture and frequency of postural shift. Further research should examine the roles of these sitting characteristics on the development of LBP.

• 열처리공학회지
• /
• 제18권1호
• /
• pp.29-40
• /
• 2005

Formation of nanocrystalline ferrite was investigated using milled powders obtained by planetary ball milling of chips, which were made by high speed mechanical cutting of a low carbon steel(0.15%C-1.1%Mn-0.01%Ti). After 4 hour milling the chips were changed to powders of $50{\mu}m$ in average size, and with increasing milling time the powders were refined to about $3{\mu}m$ for 128 hour and showed more equiaxed shapes. Nanocrystalline(nc) region appeared in the surfaces of powders milled for 1 hour, and the 4 hour milled powders were almost filled with nc region. Hardness of nc region was much higher than that of work-hardened(WH) region. With increasing milling time, ferrite and cementite in pearlite were severely deformed and lamellar spacing was decreased, and then cementites began to disappear after 4 hour milling due to dissolution into ferrite. Deformation bands formed in lightly work-hardened region showed large width and similar crystallographic orientations. Spacing of deformation bands was decreased with deformation and the layered microstructure consisting of narrow deformation bands subdivided into variously oriented small grains was formed by more deformation, and eventually this structure seemed to be evolved to the nc structure by further deformation. It is also conjectured the growth of nc ferrite grains occurred through the coalescence of nanocrystalline ferrites rather than the nucleation and growth of recrystallized grains.

• 한국직업건강간호학회지
• /
• 제17권2호
• /
• pp.191-201
• /
• 2008

Purpose: The purpose of this study were to investigate the health status and to identify the influencing factors on health status by gender among service workers. Method: Data were collected from the self-reported survey of 781 service workers in sales, food & lodging industry. The data were analyzed by descriptive statistics and multiple linear regression analysis using SPSS Win 10.0. Result: The influencing factors of male workers' health status were job satisfaction, standing hour during work time, physical work environment, job demand and family support. The influencing factors of female workers' health status were job satisfaction, emotional labor, physical work environment, regular exercise, standing hour during work time, social support and age. Conclusion: Gender specific occupational Health program for service workers should be developed in consideration of these influencing factors.

• 한국직업건강간호학회지
• /
• 제14권1호
• /
• pp.5-15
• /
• 2005

Purpose: The purpose of this study are to identify the influencing factors on work-related musculoskeletal disorders of women workers. Method: Data were collected by questionnaires from 616 women workers from in such industries as electronics, food product, garment product and analyzed using descriptive statistics, multiple logistic regression. Result: As its result, 71.3% of female manufacturing workers had musculoskeletal symptom. When Multiple logistic regression analysis on factors relating to musculoskeletal symptoms was carried out, age, work posture, job demand, type of industry, working hour, type of work, family support were statistically significant variables. Conclusion: In conclusion, this study identifies that age, work posture, job demand, type of industry, working hour, type of work, family support are important factors affecting WMSDs.

• 플랜트 저널
• /
• 제5권4호
• /
• pp.68-72
• /
• 2009

This study discussed for library development of the 3 dimensional design system for the progressive developmental world wide plant industry. Its previous background had spatial limitation by utilizing 2 dimensional CAD. This work presented an effective mode for improving man-hour by applying with 3 dimensioal design system through theoretical definition, category, and means of basic man-hour. We researched an effective method for reducing man-hour through applied example on the actual project by comprehending affection of extra development for library on man-hour.