• Title/Summary/Keyword: Work Origin

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Real-time Estimation and Compensation of Thermal Error for the Machine Origin of Machine Tools (공작기계 원점 열변형오차의 실시간 규명 및 보상제어)

  • 안중용
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1998.03a
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    • pp.148-153
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    • 1998
  • In order to control thermal deformation of machine origin of machine tools due to internal and external heat sources, the real-time compensation system has been developed. First, GMDH models were constructed to estimate thermal deformation of machine origin for a vertical machining center through the measurement of deformation data and temperature data of specific points on the machine tool. Thermocouples and gap sensors are used respectively for measurement. These models are nonlinear equations with high-order polynomials and implemented in a multilayered perceptron type network structure. Secondly, work origin shift method were developed by implementing digital I/O interface board between CNC controller and IBM-PC. The work origin shift method is to shift the work origin by the compensation amounts which is calculated by pre-established GMDH model. From the experimental result, thermal deformation of machine origin was reduced to below $\pm$5${\mu}{\textrm}{m}$.

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What is the Origin of Inequalities in Work and Health? (노동과 건강 불평등, 그 근원은 어디인가?)

  • Son, Mi-A
    • Journal of Preventive Medicine and Public Health
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    • v.38 no.3
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    • pp.241-251
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    • 2005
  • There has been an enormous increasing trend of widening gap of social inequalities since economic crisis at the end of 1997 in Korea. Since then, Korean society has deteriorated in economic and social conditions; the unemployment rate, temporary or casual workers and absolute poverty have increased. This paper presents the origin of inequalities in work and health in Korea. The origin of inequalities in work begins with the relationship between the capitalist and labourers in the capitalist mode of production. The conception and execution are dissolved in the work process in the capitalist mode of production. Thus, captitalists become control over ther labour process from workers. An alienation of the work process from the workers. The distribution of work is the majour source if inequalities in many countries as well as Korea. This paper presents the increasing tendency of unhealthy states such as mortality, early death, morbidity, physical work load, workplace injury amongst the under-privileged: ordinary workers, unemployed people, casual workers and socially deprived people in Korea.

Modeling and Compensatory Control of Thermal Error for the Machine Orgin of Machine Tools (공작기계 원점 열변형오차의 모델링 및 보상제어)

  • 정성종
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.8 no.4
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    • pp.19-28
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    • 1999
  • In order to control thermal deformation of the machine origin of machine tools a empirical model and a compensation system have been developed, Prior to empirical modeling the volumetric error considering shape errors and joint errors of slides is formulated through the homogeneous transformation matrix (HTM) and kinematic chain. Simulation results of the HTM method show that the thermal error of the machine origin is more critical than position-dependent errors. In order to make a stable and effective software error compensation system the GMDH (Group Method of Data Handling) models are constructed to estimate the thermal deformation of the machine origin by measuring deformation data and temperature data. A test bar and gap sensors are used to measure the deformation data. In order to compensate the estimated error the work origin shift method is developed by implementing a digital I/O interface board between a CNC controller and an IBM PC. The method shifts the work origin as much as the amounts which are calculated by the pre-established thermal error model. The experiment results for a vertical machining center show that the thermal deformation of the machine origin is reduced within $\pm$5$mu extrm{m}$.

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The Case Study and Its Implication on the Breach of Rules of Origin in FTAs (FTA 원산지규정 위반 판정사례와 시사점)

  • Lee, Young-Soo;Kwon, Soon-Koog
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.49
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    • pp.493-518
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    • 2011
  • The term rules of origin(RoO) actually speaks for itself, referring to the rules which determine the origin of goods in international trade. The importance of RoO has grown significantly as preferential agreements expand and countries have treated similar imported goods differently according to where the product was made. The purpose of this paper is to study the main case study and its implication of RoO in FTAs. According to survey, the degree of using FTAs in Korea export firms is sharply low. Major reasons are that rules of origin differ from country to country in the FTAs, and that Korean firms have yet to work out what the RoO are. Chapter II of this paper views criteria of the determination country of origin of goods. Chapter III introduces the main case study of FTA rules of origin. Chapter VI presents implication through the case studies and finally concluded this study. In conclusion, Korea needs to build up its own position for rules of origin and provides rules of origin experts into the market. In-depth study and evaluation about Korea's existing FTAs RoO should be carried out to prepare for future FTAs.

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On the Improvement of a Fully Recursive Formulation for the Dynamic Analysis of Multibody Systems

  • Kang, Sheen-Gil;Yoon, Yong-San
    • Journal of Mechanical Science and Technology
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    • v.17 no.1
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    • pp.77-84
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    • 2003
  • Virtual work in multibody systems is frequently expressed as the inner product of the virtual displacement and the resultant force at the centroid. But provided that the resultant force is converted into the equipollent forces there is no restriction on where the analysis reference point is placed. There are basically three candidate points : the centroid, joint point and the instant global origin. The traditional fully recursive formulation uses the centroid, but the present work verifies that the instant global origin always shows better efficiency (e.g. 86% CPU time of the centroid for quarter car model) and joint point shows the efficiency between that of the centroid and the instant global origin. A discussion on how important it is to define the analysis reference point properly in a fully recursive formulation is also presented.

The effect of country-of-origin on the product evaluation and its relation to the consumer characteristics (원산지가 상품 평가에 미치는 영향 및 소비자 특성과의 관계)

  • 전경숙
    • Journal of the Korean Society of Costume
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    • v.32
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    • pp.283-292
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    • 1997
  • The country-of-origin may be used as surro-gate indicator when the consumers do not have confidence on quality evaluation. Since the global sourcing is getting popular in inter-national textile and apparel production the ef-fect of country-of-origin should be examined. The purpose of this study was to determine the effect of country-of-origin on product evaluation and its relation to the consumer characteristics. A questionnaire was distribu-ted to 524 respondents aged 18 through 35. The results indicated that the country-of-ori-gin had significant influence on quality evalu-ation. Furthermore product components such as design price fabric and workmanship were also influenced by the country-of-origin. Price was perceived as more affected variable by country-of-origin than design fabric and work-manship. The interest in country-of-origin was different according to the consumer charac-teristics. Among demographics age and in-come turned out to be significant variables to determine the interest in country-of-origin. Shopping habits of respondents such as pur-chasing price of polo-style knit shirt the place to purchase that shirt the number of shirts they have were significantly different accord-ing to the interest in country=-of-origin. The re-spondent had higher interest in country-of-ori-gin were more fashion-conscious more confi-dent on clothing purchase more brand loyal and more sensitive to price of clothin.

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The Study of Private and Public Nature in Household Work (가사노동의 사적 특성과 공적 특성에 대한 연구)

  • 문숙재
    • Journal of the Korean Home Economics Association
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    • v.34 no.3
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    • pp.199-210
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    • 1996
  • This study is planned to investigate a discussion of private and public nature in household realm. For this purpose, first of all, study precedent concerning the household work and the private and public nature is reviewed. Second, the origin on the privacy of household work and it's relationship of the public part are investigated. Third, it is implicated that through the politicization of household work, it is enable to establish new insight of household work in the family policy.

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A simulation program practical use for an engineering improvement of the work-place (작업장의 공학적 개선을 위한 시뮬레이션 프로그램 활용)

  • Yang Hong Seok;Lee Kang bok;Youn Eui Sik;Kang Kyung Sik
    • Proceedings of the Safety Management and Science Conference
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    • 2005.05a
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    • pp.273-278
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    • 2005
  • Prescribed according to the occupational safety and health low noise measurement method was changed to personal sampling in the method to measure an area noise. Such method had the limit which did not evaluated characteristic of sound of occurrence and the place of origin. This study was performed to establish an engineering remedy of the work-place noise. The subject was a vibration control process of the place of business in Pusan. A simulation program applied for an engineering improvement of the work-place noise. The results were as follows: 1. An noise occurrence level of the work-place before improvement was $88^{\sim}97dB(A)$, We applied an improvement method to be established and were expected to $80^{\sim}119dB(A)$. 2. The level of the noise-distribution to appear in the place of origin of the work-place before improvement was $90^{\sim}93dB(A)$ but, We executed the simulation after applied an engineering remedy and predicted $80^{\sim}85dB(A)$. A result of the simulation blue part was changed mostly into the dark blue color. The results suggest that simulation program establishes an engineering remedy and is useful to the case to apply.

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A simulation program practical use to forecast the improvement effectiveness of the work place noise (소음작업장 개선효과 예측을 위한 시뮬레이션 프로그램 활용)

  • Yang Hong Seok;Lee Kang bot;Youn Eui Sik;Kang Kyung Sik
    • Journal of the Korea Safety Management & Science
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    • v.7 no.2
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    • pp.57-64
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    • 2005
  • Prescribed according to the occupational safety and health low noise measurement method was changed to personal sampling in the method to measure an area noise. Such method had the limit which did not evaluated characteristic of sound of occurrence and the place of origin. This study was peformed to establish an engineering remedy of the work-place noise. The subject was a vibration control process of the place of business in Pusan. A simulation program applied for an engineering improvement of the work-place noise. The results were as follows: 1. An noise occurrence level of the work-place before improvement was $88^{\sim}97dB(A)$, We applied an improvement method to be established and were expected to $80^{\sim}l19dB(A)$, 2. The level of the noise-distribution to appear in the place of origin of the work-place before improvement was $90^{\sim}93dB(A)$ but, We executed the simulation after applied an engineering remedy and predicted $80^{\sim}85dB(A)$. A result of the simulation blue part was changed mostly into the dark blue color. The results suggest that simulation program establishes an engineering remedy and is useful to the case to apply.