• Journal of the Korean Society for Precision Engineering
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• v.15 no.7
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• pp.61-68
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• 1998

The form accuracy of parts has become an important parameter. Therefore, dimensional tolerance and geometric tolerance are used in the design stage to satisfy required quality and functions of parts. But the informations on the machining conditions, which can satisfy the assigned geometric tolerance in design, are insufficient. The objectives of this research are to study the effects of the grinding parameters such as traverse speed, work speed, depth of cut, and dwell time on the after-ground workpiece shape, and to find out the major parameters among them. The results are as follows, The effects of work speed and depth of cut on workpiece shape are negligible compared with the effect of traverse speed. There is an optimal dwell time depending on the traverse speed. The optimal dwell time is decreasing as the traverse speed is increased.

• Safety and Health at Work
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• v.12 no.3
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• pp.351-358
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• 2021

Backgrounds: Irregular and unpredictable work schedules have become more common in most societies. The purpose of this study was to investigate the association between unpredictable work schedules and depressive symptoms in Korea. Methods: Data from 34,486 workers who participated in the Korean Working Condition Survey in 2017 were used. Unpredictable work schedules were measured by questions about the frequency of changes in work schedule and limited advanced notice. Depressive symptoms were assessed by a single item asking if the participants had depressive symptoms over the last 12 months. Multivariable-adjusted logistic regression analysis was used to calculate odds ratios (ORs) for high depressive symptoms. Results: The OR for depressive symptoms was significantly higher in the workers with unpredictable work schedules compared to those with predictable work schedules after controlling for age, sex, education, salary, marital status, occupation, contract period, full-time versus part-time, shift work, weekly working hours, and having a child under the age of 18 years (OR = 2.43, 95% confidence interval 1.93-3.07). Conclusion: Unpredictable work schedules were associated with depressive symptoms controlling for the other dimensions of precarious employment in a representative working population in Korea.

• Journal of Family Resource Management and Policy Review
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• v.6 no.1
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• pp.189-212
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• 2002

This study was purposed to explore how the information society effects on the working life of the married women. To answer the question, with theroetical background, 6 married women's cases which were selected through women's portal internet site were analysed. As results, these married women had contracting base, part-time jobs. Their jobs were chacterized by computerizing. They were different with traditional jobs in the industrial society. Internet sites were effectively used for work information network by them. So, in the future, many married women will be able to find working opportunity in a home-based part-time job through internet. And they presented aptitude for their work. Her children and husband were proud of her. They had confidence in their working ability Many women had a project publishing a book, owning a business, and making new products by her own's idea.

• Tribology and Lubricants
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• v.22 no.4
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• pp.225-229
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• 2006

The issue with the drainpipe now a day is that they are laid underground. Causing us to perform additional work to repair, such as digging up the ground and peeling off the insulator that surrounds the pipe. And such series works are difficult that concession appears from government and municipal office. However, if we can save time and money. Performance of piping robot that we are studied in existing session through fixing unit and improvement of cutting bit shorten and wished to heighten work efficiency. And we are trying to develop a unit that can cut up the projecting parts which connects with the interior part of the drainpipes.

• 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.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.5 s.98
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• pp.132-144
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• 1999

In this study, the complexity of the product was evaluated quantitatively considering the product structure, assembly process and disassembly process. To evaluate the complexity of the product, subassemblies of automobile were analyzed and then characteristics of part and subassembly were determined according to product structure, assembly process and disassembly process. Evaluation criteria of complexity were determined considering each characteristics of part and subassembly. Experiential evaluation was accomplished by classified evaluation criteria and time-motion evaluation was accomplished by the relational motion factor with characteristics of part and subassembly in MTM(Methods Time Measurement) and WF(Work Factor). The total complexity of product was determined by experiential evaluation and time-motion evaluation.

• 한국사회정책
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• v.25 no.2
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• pp.305-332
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• 2018

This study explores the effectiveness of employment-oriented welfare state by analyzing the mediating role of employment rate on the relationship between public welfare effort and fiscal soundness. Notably, this study considers the quality of employment into the analysis: part-time work, involuntary part-time work and low-wage work in analysis. The data sample consists of 18 OECD countries which initiated employment-oriented welfare strategy after the crisis of welfare state. An analysis was conduct based on Baron & Kenny(1986)'s method and panel two-stage model to handle the endogeneity problem. The results show that while the high level of public welfare effort negatively affects the fiscal soundness if it contributes to boosting employment rates, it has positive effects on the fiscal soundness. However, when the incidence of involuntary part-time employment and low-wage employment is high, the mediating impact of employment rate on the fiscal soundness disappears. This study argues that unless the quality of employment is taken into consideration, the positive effect of employment-oriented welfare state strategy to improve the fiscal soundness is not fully guaranteed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.04b
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• pp.97-101
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• 1993

In this work, the imaginary part of the inner modulation transfer function of the cutting dynamics is introduced for tool wear monitoring. Time-series method is utilized to construct the generalthree dimensional cutting dynamics whose imaginary part of the inner modulation transfer funcition shows the proportionality to tool wear at the natural frequency of the machine tool dynamics. This modelis reduced to single-input single- output model without altering the proporitonality characteristics to tool wear and implemented to the dual computer system in which one computer performs measurement while the other calculates the imaginary part of the inner modulation transfer function of th cutting dynamics by the batchleast square method. The values of the imaginary part at the natural frequencyof the machine tool structure in the cutting direction are compared to the one calculated during machining with a brand new tool to decide the current stants of the tool. The experiments shows the relevance of the proposed concept.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.170-171
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• 2015

Resource procurement and material handling are considered as a significant part of construction project especially in large or tall building construction site. There are multiple variables that must be considered in a construction site during finishing work such as movement of materials, equipments, and workers. Therefore, it is difficult for construction workers to find the material handling path solely by intuition. The aim of this study is to propose a real-time path finding model suitable for complicated logistics flow in the field. The model explores the optimal transport path of finishing material with its basis on optimization algorithm, and it determines the direction of the Smart Sign. The proposed model is expected to be utilized for planning of efficient finishing material handling.

• Journal of Family Resource Management and Policy Review
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• v.23 no.1
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• pp.115-128
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• 2019

The purpose of this study was to explore factors influencing on work values of female college students focusing on parental effect to enhance their participation in labor market. The respondents were asked to answer a questionnaire, and the collected 400 data were analyzed using SPSS 23.0. The results showed that the students and their parents had more leisure-oriented and extrinsic work values than labor-oriented and intrinsic work values. The labor-oriented and intrinsic work values appeared to be high in the group with experience of part time jobs, with high educated father or with middle household income. The influencing factors on college students' work values were parental work values, gender consciousness, self-efficacy and major. The results from this study suggest that parents of college students should be educated to change their work values.