• Design & Manufacturing
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• 제6권2호
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• pp.64-69
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• 2012

This study looks at plastic mold design for robots and mold manufacture, which is an injection mold branch at The Korea-China-Japan University Grand Prize Contest. Product analysis and layout, molding analysis, and upper and lower core design are carried out to design molds in 2D and 3D. After the design of the cores, NC machining software is used for simulation before actual manufacture. Before the production of end-product, test injection is done to troubleshoot problems like bad dimensions, burr, cracks and stepped pulley.

• 한국정밀공학회지
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• 제19권6호
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• pp.29-34
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• 2002

This paper presents formation of ejector-pin hollowness in injection molding. Injection molding process is widely used in production of plastic part for good dimensional accuracy and high productivity. However, the injection molding leaves ejector-pin hollowness on pal, which causes bad part surface and quality. Dimensions and profiles of ejector-pin hollowness are measured for formation or ejector-pin hollowness. The formation of ejector-pin hollowness is traced with dimensions and profiles of ejector-pin hollowness. The compression force and moment cause ejector-pin to form hollowness on part surface.

• 경영과정보연구
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• 제28권4호
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• pp.45-66
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• 2009

본 연구는 최근 세계적인 이슈가 되고 있는 기업의 CSR성과와 기업의 지배구조가 체계적인 관련성을 가지는가에 대한 실증적인 분석을 하였다. 양호한 기업지배구조를 가진 기업은 더 높은 CSR성과를 가진다는 가설을 설정하고 국내 CSR성과 자료를 이용하여 실증적인 검증을 시도하였다. 이러한 가설을 검증하기 위하여 기업지배구조의 변수로 국내기관투자자지분율, 외국인투자지분율, 사외이사비율, 감사위원회도입과 CSR성과의 측정치로 한국경제정의연구소(KEJI)의 지수를 이용하여 1998년부터 2005까지 상장기업 130개 기업을 검증하였다. 연구결과 양호한 기업지배구조를 가진 기업과 CSR성과는 통계적으로 유의한 관계를 가지고 있는 것으로 나타났다. 기업지배구조의 변수 중 외국인투자지분율, 사외이사비율, 감사위원회도입과 CSR성과는 통계적으로 유의한 정의 관계를 나타내고 있다. 이러한 연구결과는 양호한 기업지배구조를 가진 기업은 더 나은 CSR성과로 나타나고 궁극적으로 기업가치를 높일 수 있는 연결고리를 보여주고 있으며, 기업의 지배구조개선으로 CSR성과를 제고시키는 전략적 수단이 될 수 있다는 점을 시사하고 있다. 특히, 본 연구결과는 한국기업이 CSR활동에 있어서는 여전히 걸음마 수준에 있는 만큼 많은 경영자들에게 기업의 지배구조와 CSR에 대한 새로운 인식을 가질 수 있는 계기가 될 수 있음을 보여주고 있다.

• 대한조선학회 특별논문집
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• 대한조선학회 2009년도 특별논문집
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• pp.47-51
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• 2009

It is well known that a rudder is influential devices to help ship maintain its stable performances, such as a course-keeping and maneuverability. In the procedures of a commercial ship design proper rudder dimensions (area and shape) ensuring better ship maneuverability have been settled in an initial concept design stage performed by a preceding department, without little structural consideration. It is true that there are time discrepancy between an initial design and a structural analysis stage. Therefore structural analysis results would sometimes cause a rudder to modify its dimensions. Most of these cases, however, ship design and performance tests had been finished. In this matter, only limited modifications of redder could be carried out. Besides, these could also cause bad effects on productivity. Finally, it is necessary to develop a new program considering co-relationship between an initial rudder design and a following work, a structural strength analysis, in order to enhance productivity and minimize a rate of redesign procedures.

• The Journal of Asian Finance, Economics and Business
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• 제7권2호
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• pp.131-141
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• 2020

This study examines the poverty indicators in Northeast region of Thailand by adopting the global Multidimensional Poverty Index (MPI) methodology and the national survey of Minimum Basic Needs (MBN) of Thailand. Data are collected from three different districts in Khon Kaen province namely: Khok Po Chai, Sam Sung, and Nam Pong. The sample size is 187 households. Data analysis uses Ordinary Least Square (OLS) regression approach and includes 7 dimensions of poverty (health, environment, education, economy, Thai value, asset? empowerment, and digital literacy) with a total of 41 indicators. This study has found that poverty indicators in Khon Kaen province remains centered around the aspects of health and employment dimensions. While a change of family structure in the Thai society since 1960s reduces the family size, household saving substantially increases over the years. The effects of health dimension in poverty, on the other hand, appears on the other poverty dimension of Thai value, which include (1) a bad living habit of head of household (smoke or alcohol consumption) that links with illness and disease, (2) religious practice, and (3) chronic illness. Lastly, there are income gaps of different careers in the area, which suggests the issue of income inequality.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.205-209
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• 2007

During after the Industrial Revolution until now, as many of working machinery and tool had been invented, human could save man power and time. However, because such instruments generate a loud noise according to their use-purposes and dimensions, they are affecting a physical, mental bad influences to those workers. Therefore, while a reduction measure against the instrument-noise that generates at workshop is sincerely necessitated, due to lack of the research and data concerned with that, a lot of difficulties are on suffering. Standing on such point of view, this Study has measured analyzed the characteristics of diverse instrument-noises generate at workplace, and would intends to present a fundamental material for establishment more comfortable working environment by prediction on the noise in loud noise workshop, based on the above.

• Design & Manufacturing
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• 제7권1호
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• pp.1-6
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• 2013

The injection molding process is a predominant method for producing plastic parts. In order to maximize productivity and molding quality in a injection mold, it is important that each cavity in a multi-cavity injection mold is identical. This requires that cavity dimensions should be identical and delivery system of melt to each cavity have to be the same. Despite the geometrically balanced layout in multi-cavity injection mold more than 4 cavities, it has been observed that the filling in each cavity results in imbalances. Most of cases, this phenomenon of filling imbalances have a bad effect on dimension accuracy, warpage, molding appearance and strength of molding parts. In this study, experiment were conducted to investigate the effect of filling imbalances on the molding quality(surface gloss, shrinkage, tensile strength) in the multy-cavity injection mold.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.844-847
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• 1996

This paper describes the servo position control for the 2-axis positioning table the servo controller consists of conventional feedback loops, disturbance observer. To reduce the contour error, which occurs in the multi-dimensions machines, cross-coupled controller(CCC) is suggested. A weak point of the CCC is their low effectiveness in dealing with arbitrary nonlinear contour such as circles and parabolas. This paper introduces a new nonlinear CCC that is based on control gains that vary during the contour movement The gains of CCC and adjusted in real time according to the shape of nonlinear contour. The feedback controller based on the disturbance observer compensated for external disturbance, plant uncertainty and bad effectiveness by friction model. Suggested servo controller which improve the contouring accuracy, apply to the 2-axis system. Simulation results on 2-axis table verify the effectiveness of the proposed servo controller.

• 한국소음진동공학회논문집
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• 제14권10호
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• pp.968-974
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• 2004

Automakers have been forcing their suppliers to guarantee qualities of parts. Then, the suppliers have met the fundamental quality requirements such as dimensions and functions, but they could not sufficiently satisfy the automakers' noise requirements yet because automatic noise inspection systems were little successfully adopted In mass-production lines. This study tried to develop a system for automatically checking noise radiated from a rotating engine part and filtering parts emitting noise higher than criteria: the upper limits of a overall noise level or a noise spectrum. A commercial noise measurement system was used for measuring noise, and then the noise data was transmitted to a governing program through OLE(object, linking and embedding) functions. The governing program, belonging to a total noise inspection system managed the noise measurement and analysis. This system was successfully adapted for distinguishing bad parts according to the noise criteria.

• 한국금형공학회:학술대회논문집
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• 한국금형공학회 2008년도 하계 학술대회
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• pp.89-94
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• 2008

The injection molding process is a predominant method for producing plastic parts. In order to maximize productivity and molding quality in a injection mold, it is important that each cavity in a multi-cavity injection mold is identical. This requires that cavity dimensions should be identical and delivery system of melt to each cavity have to be the same. Despite the geometrically balanced layout in multi-cavity injection mold more than 4 cavities, it has been observed that the filling in each cavity results in imbalances. Most of cases, this phenomenon of filling imbalances have a bad effect on dimension accuracy, warpage, molding appearance and strength of molding parts. In this study, experiment were conducted to investigate the effect of filling imbalances on the molding quality(surface gloss, shrinkage, tensile strength) in the multy-cavity injection mold.