• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.880-884
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• 1995

Manufacturing environment is getting characterized by unstable market demand,short product life cycle and timebased competition. For adapting this environment,machine tools have to be further versatile functionally in order to reduce part's set-up time. Unlike existing manufacturing systems mainly to focus on part flow, it is important to control tool flow using fast tool change device and tool delivery device in parallel machines consisting of versatile machine tools, because complete operations on a part can be performed on one machine tool in a single machine set-up. In this paper, under dynamic tool allocation strategy to share tools among machine tools, we propose a real-time tool allocation and operation esequence model with an objective of minimizing flow time using autonomy and negotiation of agents in parallel machines

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.198-207
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• 1994

공작기계부품 가공을 위한 공정표는 가공공정, 공정별 도면 분할, 가공기계 등을 결정하는 공정계획과 한 공정에 대하여 가공방법, 가공공구, 절삭조건, 공수등을 결정하는 작업계획을 통하여 발행된다. 작업계획에서 가공방법과 가공공구의 결정은 절삭조건과 공수에 영향을 주는 중요한 요소이다. 기존의 연구에서는 가공방법과 가공공구를 결정하기 위해 전문가 시스템 쉘(expert system shell)이용한 사례가 많았다. 이 경우, 지식 베이스(knowledge base) 의 구축에 많은 시간이 소요되고, 지식이 변했을 때 수정의 어려움이 있다. 본 연구에서는 표준화되지 않아 변경의 소지가 많은 가공방법과 가공공구 결정에 뉴럴 네트워크(neural network)의 한 종류인 백 프로퍼게이션 (back propagation) 학습 모델을 이용했다. 공정계획 후 분할된 공정별 도면으로부 터 크기 및 정밀도 등과 같은 특징형상(feature) 정보를 추출한 후, 특징형상 의 종류와 크기, 치수공차, 기하공차, 거칠기 등을 입력하여 가공방법 및 가 공공구가 출력되도록 학습패턴을 설정하여 학습시켰다. 학습패턴은 공정설계 전문가와 인터뷰하는 방법과 작업계획 과정을 분석하는 방법을 통하여 설정 했다. 백 프로퍼게이션 모델을 통하여 학습시킨 결과, 학습시킨대로 정확한 가공방법 및 가공공구를 결정할 수 있었다.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• v.10 no.2
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• pp.237-240
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• 2005

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.07a
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• pp.226-231
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• 2003

벼 저장에 영향을 주는 중요한 인자는 벼의 수분함량, 온도 및 습도이고, 이 이외에 생리적 현상으로서 곡물 자체의 호흡작용으로 인한 발열현상과 생물학적 요인으로는 해충, 미생물, 쥐 등이 있다. 따라서 저장성을 높이고 고품질로 유지하기 위해서는 저장 시 환경조건이 중요하며 현재 국내 환경에 적합한 벼 저장시설을 개발하기 위한 연구가 다각도로 진행되고 있다. (Kim 등, 1999, Keum 등, 2000) 일본의 경우 북해도 지역에서 자연냉기로 벼를 냉각시켜 곡온을 저온으로 유지하면서 고품질로 장기간 콘크리트 사이로에 저장하는 기술을 개발하여 보급하고 있다. (천촌주삼, 2000) (중략)

• Journal of Biosystems Engineering
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• v.23 no.3
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• pp.253-258
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• 1998

The part I was for developing regression models to predict the moisture content, protein content and viscosity of brown and milled rice using Near Infrared(NIR) Reflectance analyzer. The purpose of this study(part II) is to measure fundamental data required for the prediction of rice quality, and to develop regression models to predict the protein content of brown and milled rice, brown rice yield from undried paddy powder by using Near Infrared(NIR) Reflectance analyzer. The results of this study were summarized as follows : The predicted values of protein contents obtained from the undried paddy powder were well correlated to the measured values from brown and milled rice. The predicted yields of brown rice from undried paddy powder were not well correlated to the lab measured values from dried paddy. Continuous study in wavelength selection and of constituent relationship is necessary for practical application.

• Journal of the Korean Operations Research and Management Science Society
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• v.28 no.1
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• pp.1-10
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• 2003

A recent trend In flexible manufacturing systems (FMS) Is to utilize the Identical versatile machines with fast tool delivery devices. Unlike a conventional FMS where parts are fed to the machines with the required tools, tools are acquired from other machines using a tool delivery system and parts can be finished on the same machine In these FMS. Therefore it Is more important problem 4o plan tool flow using tool delivery system In these FMS rather than part flow In conventional FMS. According to the existing study, In FMS 20∼30 percent of the total management cost Is the cost related with tools and It Is possible to reduce the tool Inventory by 40 percent using efficient tool allocation. In this study, In FMS under dynamic tool allocation strategy, a new method of part release considering tool flow at the stage of part release Is proposed. In order to prove the efficiency of the proposed part release It is compared with other part release through simulation experiments. Performance measures in these experiments are the throughput and the number of tardy parts.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1998.06b
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• pp.171-177
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• 1998

The part Ⅰ was for developing regression models to predict the moisture content, protein content and viscosity of brown and milled rice using Near Unfrared (NIR) Reflectance analyzer. The purpose of this study(part Ⅱ) is to measure fundamental data required for the prediction of rice quality , and to develop regression models to predict the protein content of brown and milled rice, brown rice yield from undreid paddy powder by using Near Infrared (NIR) Reflectance analyzer. The results of this study were summarized as follows . The predicted values of protein contents obtained from the undried paddy powder were will correlated to the measured values from brown and milled rice. The predicted yields of brown rice from undried paddy powder were not well correlated to be lab measured values from dried paddy. Continuous study in wavelength selection and of constituent relationship is necessary for practical application.

• Journal of the Korean Society for Railway
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• v.10 no.2 s.39
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• pp.161-166
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• 2007

Recently, The business environment is very rapidly changed and complicated. Therefore, the companies are confront with the biggest difficulty. To overcome this difficulty, the management should be able to accomplish the human resources management and the efficient business management. Korea railroad industry has a close association with national life as it carries out public works based on its public nature as well as purses the corporate spirit. For that reason, Korea railroad industry has a great spin-off on national economy and exerts a tremendous impact on the improvement of productivity around the industries and the international competitiveness at aspect of efficiency resulting from business rationalization. Railroad system can be described as organic. Railroad Employs take a great role in this system. According the psychology and the Organization Behavior, the decision maker's personality and employee' work satisfaction have influence on performance. The purpose of this study is to examine the Railroad Employs' Personality and Work satisfaction which influence on the efficient business management.

• Korean Journal of Materials Research
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• v.12 no.6
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• pp.482-487
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• 2002

A $TiO_2$ film for photocatalyst was prepared by anodic oxidation at 180V in acidic electrolyte and film formation mechanism was studied. The major part of anodic $TiO_2$ film consisted of anatase type structure and surface morphology exhibited a porous cell structure. The thickness growth rate of the oxide film with anodization time revealed two-stage slope corresponds to the surface morphology between anodic films. The growth of pores on cell structure and the growth rate of film with two-stage slope are related to the constant formation rate of the $TiO_2$ layer.

• Advances in pediatric surgery
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• v.3 no.2
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• pp.168-171
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• 1997

Appendiceal perforation is uncommon in the neonate. Diess reported the first case in 1908. Approximately 111 additional cases have been reported since that time. However, with exclusion of neonatal appendicitis associated with inguinal or umbilical hernias, necrotizing enterocolitis, meconium plug, and Hirschsprung's disease, there are only 36 cases of primary neonatal appendicitis. We treated a 12 days old boy with perforation of the appendix. The infant was 3000 g at birth and had a normal spontaneous vaginal delivary at 35 weeks of gestation. The mother was 31-year-old and had premature rupture of membrane. After normal feeding for the first 5 days of life, the infant had emesis of undigested milk, decreased activity and jaundice. The baby was admitted to the Pediatrics. Progressive abdominal distension, fever, decreased activity, and vomitting developed over the next six days. Erect abdominal radiography showed pneumoperitoneum. At exploratory laparotomy, a $0.8{\times}0.6$ cm sized perforation was noted at antime-senteric border of midportion of the appendix. Trasmural inflammation and the presence of ganglion cells were noticed on histology.