• Journal of the Korean Society for Precision Engineering
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• v.23 no.12 s.189
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• pp.38-45
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• 2006

In this work, optimal finish machining condition considering total time for mold or electrode manufacturing was investigated. First, manual finishing time according to the machining condition was analyzed for the work material. The effect of runout and phase shift of tool path on surface finish was also considered in those analyses. Secondly, optimal manual finishing processes were determined for various machining conditions. Finally, finish machining time and corresponding manual finishing time were taken into account for the estimation of the total time of manufacturing mold. Though small feed per tooth and pick feed reduced the manual finishing time, the finish machining time increased in such conditions. With a machining condition of feed per tooth of 0.2 mm and pick feed of 0.3 mm, the minimum total time of manufacturing mold was achieved in our machining condition.

• Korean Management Science Review
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• v.20 no.2
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• pp.33-43
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• 2003

In this paper we applied dynamic programming to determining work schedule type. In dynamic programming formulation, each day during a planning horizon represents a stage for which a decision is made. The alternatives are given by work schedule types that combine regular time, overtime, additional shift, and so on. In this case, their associated return function is labor cost. The state is defined as the amount of work time allocated to stage 1, stage 2,…, and current stage. A case study for a real manufacturing company was performed to apply dynamic programming to scheduling daily work hours during a week. The case study showed that total cost of our solution derived from dynamic programming decreased by about 6％ as compared with the solution obtained from the previous method.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2007.11a
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• pp.477-481
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• 2007

The purpose of this study is to provide the ideal forecasting model of cadastral survey work load through the Economeatric Analysis of Time Series, Granger Causality and VAR Model Analysis, it suggested the forecasting reference materials for the total amount of cadastral survey general work load. The main result is that the derive of the environment variables which affect cadastral survey general work load and the outcome of VAR(vector auto regression) analysis materials(impulse response function and forecast error variance decomposition analysis materials), which explain the change of general work load depending on altering the environment variables. And also, For confirming the stability of time series data, we took a unit root test, ADF(Augmented Dickey-Fuller) analysis and the time series model analysis derives the best cadastral forecasting model regarding on general cadastral survey work load. And also, it showed up the various standards that are applied the statistical method of econometric analysis so it enhanced the prior aggregate system of cadastral survey work load forecasting.

• Journal of the Korean Home Economics Association
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• v.35 no.2
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• pp.345-358
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• 1997

This study investigated the pattern of division of household labor between married couples and the determining variables of the division of household work. In addition, this study examined the effect of the pattern of the division of household work and the sense of fairness on marital satisfaction. Two hundreds forty two married couples living near seoul were selected. Both wives and husbands reported their daily time-use pattern. According to the results, flexibility of husbands' work schedules hours of market work of husbands, husbands' sex role attitudes, and the presence of household assistant affected significantly on the extent of household work time. In addition, husbands' household work time had direct effects on marital satisfaction of couples. In wives' hours of household labor, the significant variables were wives' employment status, presence of younger children, total income, wives' sex role attitudes, and hours of household labor performed by housework assistant. In addition, wives' sense of fairness had impact significantly on marital satisfaction.

• Proceedings of the Safety Management and Science Conference
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• 2001.11a
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• pp.139-143
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• 2001

Work-related injurieshave become the issue in the twentieth century. Musculoskeletal disorders are the most common work-related injuriesand the most frequent from of work-related i11-health (more than 50％ of total work-related injuries (BLS 1990)). The workers at copy shops have complained of pain in their back, legs, and shoulders. Most of them work for more than 8 hours a day. They have claimed that their pains were associated with repetitive and continuous work over a long term. The purpose of this research is to suggest an ergonomically comfortable redesign of the copy machine. This study was performed by conducting a survey of copy shop workers who have complained of job-related physical pain, and analyzing their working postures. The copy machine was ergonomically modified to reduce the workers' pain. The VIS10N 3000 software was used to analyze the posture. The analysis showed significant difference in the ranges of back and neck motion (p<0.05).

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.5-7
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• 2012

Repeated using carpentry workers work at working tools because of occupational low back pain, such as musculoskeletal disorders, occupational diseases are on the rise. For this purpose, through the analysis of musculoskeletal disorders and work tools and studies are underway to improve the working conditions of the workers. However, existing previous studies may not reflect the working tools used for carpentry worker dies when working at a construction site that Therefore, in this study, the work in the form of construction, one of the jobs of worker dies classified according to the working tools of musculoskeletal disorders correlated to analyze. The results of this study are as follows. working tools of a total of seven different dies used in the installation process. Musculoskeletal disorders, waist / drill such correlation was very strong. Also showed that a total of three of the tools used in the formwork dismantling cutter musculoskeletal disorders of the arm / elbow and a very strong correlation.

• Journal of the Korean Society of Safety
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• v.31 no.6
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• pp.74-83
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• 2016

The purpose of this study was to identify the educational and ecological factors (environment and infra-structure) associated with workers' participation to safety and health education at work (SHEW) based on the PRECEDE constructs. A total of 590 workers (484 in manufacturing and 106 in construction companies) finished the self-administered survey. Survey packets were delivered to the safety and health manager (SHM) in survey companies and the SHMs conducted the self-administered survey in their companies. The questionnaire includes demographics, epidemiological constructs, and educational and ecological constructs based on the PRECEDE model. Participation to SHEW was better in the manufacturing sector than in the construction sector (p<.001). Environmental, reinforcing, and enabling factors were better in the manufacturing companies than in the construction companies. Male worker, better perceived efficacy of SHEW, higher social support for SHEW, assignment of SHM at work, and better safety and health management level at work were significantly associated with workers' better participation to SHEW (p<.05). Those factors accounted for 45.9% of total variance of workers' participation to SHEW.

• Journal of the Korea Institute of Building Construction
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• v.12 no.2
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• pp.169-182
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• 2012

In the past, a strategic management of work demands has been increasingly challenged to design-build (DB) firms. Such a management is capable of providing sufficient profitable impact of a project on them. Total project profit is mainly related to actual resources, work completion time, amount of rework, and costs. The degree of recycling work packages in the DB project delivery system is used as a measure of the quality of the performed work. However, there are few models available to evaluate the impact of a demand management strategy on the DB firms and to predict its behavior. We propose a decision-making support model as an aid for assessing the amount of rework and for predicting project profit resulting in a convincible demand management strategy. This model is constructed by using a dynamic feedback approach that can analyze the problems arising in complex managerial systems. For the purpose of illustration, widely acceptable strategies were applied into the model to explore their impacts on the DB firms. The results indicate that the model is helpful for the managers in selecting the most appropriate demand management strategy for successfully achieving their objectives.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.2
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• pp.174-184
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• 2020

Objectives: The purpose of this study was to improve the working environment by identifying the work satisfaction of the cleaning workers of the aircraft and measuring and assessing the harmful factors of the cleaning process. Methods: We asked 23 cleaning companies for questionnaires and got 100 answers from 5 companies. The A-E Airline health manager has been contacted to establish a site survey schedule. The in-flight and lounge were measured using direct reading equipment. The harmful factor to be measured are noise, dust, temperature, volatile organic compound, total airborne bacteria, and total airborne bacteria. Results: Uncomfortable positions when replacing blanket, cleaning the table, and cleaning the floor have been identified as factor that reduce work satisfaction. Noise when replacing newspapers and cleaning toilets has been identified as a factor that lowers work satisfaction. Temperature and humidity were found to reduce work satisfaction during in-flight disinfection. Measurements of aircraft cabin and lounge with direct read equipment have shown that none of the items exceed the exposure criteria. Conclusions: As a result of measuring direct-reading equipment, no items exceeded the exposure criteria for each harmful factor. A clear survey of the working environment is required based on the results, and additional research is needed using personal sample measurement.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.637-642
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• 2007

The sum of each work duration are entire period in construction project. Each work occurs to be late, the total period of construction project will delays. Therefore, the total period of construction project will not be delayed if probability of working progress makes higher. Finding each work's constraints performs constraints analysis in process of construction for checking probability of working progress. Grasp work's constraints through the constraints analysis and removes. This research will show preventing delay of consruction project, through constraints analysis process.