• Title/Summary/Keyword: Work duration

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Effect of various work factors on push-pull strength and muscle recruitment pattern (작업 요인이 push-pull strength와 근육 동원 패턴에 미치는 영향)

  • 심정훈;이상도
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.25 no.4
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    • pp.46-53
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    • 2002
  • Push-pull strength has been found to be associated with various work factors such as height, distance, repetition, duration, posture and individual factors. Therefore, this study was performed to investigate the effect of various work factors on push-pull strength and muscle recruitment pattern. Work factors were consisted of grip height(elbow, shoulder), grip distance(100%, 50%, and 25% of maximum grip distance) and shoulder angle(neutral($90^{\cire}$), and abduction($45^{\cire}$, $0^{\cire}$)) during sitting work. The results showed that the normalized strength and EMG value were higher at the elbow height than the shoulder height, and increased with grip distance and shoulder adduction. The results of ANOVA showed that there was significant difference on muscle recruitment patterns among the task conditions. Therefore, it is necessary to consider work factors as well as strength to prevent workers from work-related injuries.

The Effects of Household Characteristics and Poverty Duration on Poverty Exit Rate -Examining the Effects of Duration Dependency and Sample Heterogeneity - (가구특성과 빈곤지속기간이 빈곤탈피율에 미치는 영향 -지속기간의존성과 표본이질성에 대한 검증을 포함하여-)

  • Kim, Hwanjoon
    • Korean Journal of Social Welfare Studies
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    • v.44 no.3
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    • pp.301-322
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    • 2013
  • By analyzing wave 1~11 (1998~2008) of Korean Labor and Income Panel Study(KLIPS) database, this study examines the effects of household characteristics and poverty duration on poverty exit. A special concern is to decide whether the decrease of poverty exit rates comes from true duration dependency or from the sample heterogeneity as poverty duration progresses. I also analyzed how the effects of independent variables are changed when unobserved heterogeneity is controlled. The results show that duration dependency disappears after controlling observed household characteristics and unobserved individual heterogeneity. This finding confirms that the apparent relationship between poverty exit rate and poverty duration is in fact a spurious association due to the sample heterogeneity rather than true duration dependency. In addition, the effects of household characteristics on poverty exit rate become more stronger when unobserved heterogeneity is controlled. Socioeconomic factors affecting poverty exit rates are such as householders' age, education, household composition, number of family members, labor force participation, and work status.

A Study on the Productivity Analysis of Deck Plate Installation Work in Steel Structure Construction (철골조 데크플레이트 공사의 생산성 분석에 관한 연구)

  • Jeong, Se-Lim;Cho, Kyu-Man;Hyun, Chang-Taek
    • Journal of the Korea Institute of Building Construction
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    • v.10 no.1
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    • pp.73-79
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    • 2010
  • Deck plates have been widely used for steel framework due to their merits in terms of schedule reduction and work repetition. For this reason, most of the previous studies related to deck plates have focused on the development of form type and their constructability. In this study, through an actual case study and interviews with experts, a simulation model was developed using the CYCLONE method. Based on this model, this study not only analyzed the productivity of the work process of the deck plate in steel framework, but also identified the occurrence of idle time in the work process. In addition, using a sensitivity analysis, productivity and duration could be analyzed according to variation of input resources. Based on the results, this paper suggests a way to improve the productivity of deck plate work in steel frameworks. Using the model, it is expected that project managers would be able to predict the productivity and total duration of the deck plate work in the early project phase, which will enable managers to make an appropriate plan for input resources.

Health Risks Related to Shift Work Among Female Workers of Major Manufacturing Industries in Korea (우리나라 여성 주요 제조업 근로자들의 교대 작업에 대한 건강영향 평가)

  • Shin, Eui-Chul;Meng, Kwang-Ho
    • Journal of Preventive Medicine and Public Health
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    • v.24 no.3 s.35
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    • pp.279-286
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    • 1991
  • Much of the working population in developing countries are engaged in shift work now and the number of shift workers is not expected to decrease in the future mostly because the need for continuity of production is increasing. Therefore, the possible effects of shift work on health are of particular interest, and in fact, there have been many epidemiological studies on shift work since the first world war. However, no studies on health effects of shift work have been reported in Korea, and the existing studies in western world have arrived at quite different conclusions mainly because the conditions of work other than shift work, such as age and selection of workers, work environment, and labor conditions also influence the health of workers. This study was firstly carried out in Korea to investigate the health risks related to shift work with 2,093 female workers randomly selected from three major manufacturing industries in proportion to total number of female workers in those industries. Differences of work conditions other than shift work in this study were adjusted by multivariate analysis. Ma findings obtained from this study are as follows : 1. There were significant differences between shift and day workers in the distribution of age, type of industry, condition of noise and dust, regularity of mealtime, working position, and working duration. Shift workers tended to be younger, to have shorter working duration, to have more irregular mealtime, to work in standing position, and to work under more noisy and dusty environment than day workers. 2. Univariate analysis showed that shift work increased the Todai Health Index (THI) scores of digestive tract, respiratory tract, and mental instability symptom categories. Shift work also increased days of sickness absence and number of industrial accident per 100 workers per month. 3. Multivariate analysis that adjusted the differences of demographic, occupational and non-occupational health-related working conditions showed that digestive tract symptom and mental instability symptom scores were significantly higher in shift workers than those in day workers. Based on these study results, it is concluded that the shift work has significant effects on some psychophysiological conditions of the workers and the effects are also influenced by several other personal and working conditions.

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A Study on the Applicability of Non-Supporting System Forms for Single Face Walls in Underground Construction (지하층 합벽 무지주 시스템 거푸집의 적용성에 관한 연구)

  • Kim, Jae Yeob;An, Sung-Hoon;Sohn, Young-Jin
    • KIEAE Journal
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    • v.8 no.2
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    • pp.87-92
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    • 2008
  • Underground building constructions are recently more important because the ratio of underground area is increasing in the huge and high-rise building construction projects. For reducing the total building construction periods, it is required to reduce not only the over-ground structural work periods but also the underground structural work periods. Therefore, this study is proposed the non-supporting system forms for single face walls in underground building construction by one of the methods for reducing the underground structural work periods and investigated the applicability of the non-supporting system forms by analyzing the case-study in civil construction project. In regard of construction duration, the results of analyzing the case-study showed that the non-supporting system forms are better than the euro forms with soldier system for single face walls in underground building construction. In addition, it is showed that the cost of these two forms is similar and usage the working space and safety in non-supporting system forms are better that those of the euro forms with soldier system, too.

A Study on the Subjective Symptoms of VDT Syndrome in Radiological Technologist Using Computer Keyboard (컴퓨터 단말기를 사용하는 방사선사의 VDT 증후군에 관한 연구)

  • Lee, Byoung-Nam;Lee, Kang-Woo
    • Korean Journal of Digital Imaging in Medicine
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    • v.5 no.1
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    • pp.138-149
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    • 2002
  • During the period from may to June 2000, a questionnaire study was carried out on 65 male radiological technologist who had been engaged at VDT work, to find out correlation their symptoms to VDT syndrome factors, work environment and condition. The results were as follows : 1. The mean age was 41.0 years, the mean relay working time was 3.75 hours and the mean duration of using computer monitor was 5.9 years, the satisfactory of working was 44.6% the others 55.4%, among these, 3.1% had symptoms before using the VDT and the others had not. 2. The prevalence of symptoms was the highest on wholebody tired, followed by eye, neck, low back, in decreased order and the lowest was fatique of wrist. 3. There was not significant correlation of symptoms to age, but significant to working time, working duration. 4. There was not significant correlation of symptoms to satisfactory. 5. Working desk, monitor, illuminations, temperature, and noise were significantly related to symptoms. 6. There was significant relation of symptoms to CT, MRI workers.

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The Smoothing of Rainfall Intensity - Duration - frequency Relationships curve by the Box-Cox Transformation (Box-Cox 변환에 의한 I-D-F 곡선의 평활화)

  • Lee, Hee-Chan;Seong, Kee-Won
    • Journal of Korea Water Resources Association
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    • v.36 no.2
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    • pp.153-159
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    • 2003
  • When available rainfall data is not sufficient, a rough tendency of I-D-F relationship appeared frequently. In fact, rainfall intensity on the curve shows abnormally higher value the longer rainfall duration is applied that gives rise to great confusion to apply a rainfall I-D-F relationships curve to a practical work, however, the research work will present a way to solve above mentioned problem by the use of the Box-Cox transformation formula for a given rainfall data. The study came to a conclusion that the Box-Cox transformation formula is satisfied to utilize in a practical work on the ground of analysis for rainfall data of Sancheong and Yeongcheon.

Characteristics of Drone Broadcasting Camera Moving through Content Analysis Method (내용분석을 통해 본 드론 방송영상의 카메라 움직임 특성 연구)

  • Lim, Hyunchan
    • Journal of Korea Multimedia Society
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    • v.24 no.8
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    • pp.1178-1183
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    • 2021
  • Based on the camera movement on image expression and grammar, this study intended to analyze the characteristics of image expression filmed and broadcasted by drones. This study analyzed drone images using the movement characteristics of existing video cameras as a coding nomenclature. These were intended to examine the differences from existing video grammar and their implications. This study conducted a content analysis using the entire population of drone news footage broadcast for four years in 2015, 2016, 2017 and 2018 by TV Chosun. The size of the screen, camera work, duration of the shot, camera angle, etc. were selected and analyzed. As a result, the drone camera work showed that it uses the most dolly shots in the case of camera movement, followed by the drone camera movement in the order of pan and tilt shots. For zoom, the frequency of use was the smallest. In addition, this study analyzed the size of the screen, duration of the shot, and camera angle of drone. Analysis shows that drones use certain camera movements most frequently, and unlike grandiose modifiers such as "extension of human gaze," drone remains as a supplementary means to enhance the traditional media expression.

Correlation Analysis on the Duration and CO2 Emission Following the Earth-work Equipment Combination (토공장비조합에 따른 공사기간 및 이산화탄소 배출량의 상관성 분석)

  • Kim, Byungsoo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.4D
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    • pp.603-611
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    • 2011
  • After Kyoto Protocol was adopted for green gas reduction, each nations are stepping up efforts to reduce $CO_2$ of a typical green gas. Construction industry also is trying $CO_2$ reduction with the techniques of two types which are software and hardware techniques. The software technique are Passive Design considered green gas emission and the environment impact assessment by LCA. The hardware techniques are adjustment of equipment system and development of eco- friendly material. But, it is nonexistent that a study related to $CO_2$ emission considered detail process in construction industry. This study analyzed the correlation of equipment combination, $CO_2$ emission and duration by calculate $CO_2$ emission follow to equipment combination on earth-work which is the process emitted most $CO_2$ among railway bedding construction.