• Tribology and Lubricants
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• 제20권1호
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• pp.21-26
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• 2004

The average frictional coefficient was used generally to analyze the working process of the lubricated machine parts. But it is difficult of taking the correct frictional coefficient because the average frictional coefficient of it is progressed always unstably with a large amplitude on working condition. If the correct analysis of frictional coefficient on working condition for the lubricated machine parts can be possible, it can be effect on condition diagnosis of lubricated machine system. This study was carried out to get the optimum working condition of the hydraulic actuator parts using statistical techniques. From this result, it has the lowest friction coefficient in case of applied load of 3 kg and sliding speed of 120 mm/sec.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1996년도 춘계학술대회 논문집
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• pp.18-23
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• 1996

The Job of Milling in the Local Skill Contest in 1996 was to assemble parts into a complete whole of the parts number 1, 3, 4 worded by Milling Machine and the parts number 2 worked by Machining Center. In the parts of Milling Machine, the Job was to work 45$^{\circ}$angle working, T-slot, dovetail, the correct position drilling, rimming, boring, etc. In the Machining Center, there were the way of calculation of point of contact of 'R' contour curved line and lots of working elements. So, it was possible to work the parts and assemble them within the time limit only through the program to be made out in the way to shorten working hours.

• 한국자동차공학회논문집
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• 제12권3호
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• pp.184-191
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• 2004

In this study, an inspection system for automotive parts using machine vision has been developed and presented. The system is comprised of six analog CCD cameras, frame grabber, and mechanism that loads the automotive parts to the system for the inspection. An Image processing algorithm for detecting eight different types of defects of oil-seals are developed, and the effectiveness of the algorithm is experimentally verified. Inspection process is completed in 1 second with acceptable accuracy. It is envisaged that this inspection system will have a wide application in the automotive part manufacturing industry in the future.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
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• pp.375-380
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• 2003

This study is concerned with the machine part grouping m cellular manufacturing. To group machines into the set of machine cells and parts into the set of part families, new p-median model considering the production data such as the operation sequences and production volumes for parts is proposed. Unlike existing p-median models relying on the classical binary part-machine incidence matrix which does not reflect the real production factors which seriously impact on machine-part grouping, the proposed p-median model reflects the production factors by adopting the new similarity coefficient based on the production data-based part-machine incidence matrix of which each non-binary entry indicates actual intra-cell or inter-cell flows to or from machines by parts. Computation test compares the proposed p median model favorably.

• 한국컴퓨터정보학회논문지
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• 제5권4호
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• pp.48-54
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• 2000

본 논문에서는 한ㆍ영 기계번역을 위한 한국어의 품사를 분류하였고 각 품사의 형태론적 특징을 고찰하였다. 한국어 표준문법에서 제시되는 품사 분류 기준은 의미, 기능, 형태의 세 가지 기준을 적용하고 있으며, 자연언어처리에서도 같은 분류 기준을 바탕으로 하고 있다. 품사 분류에 여러 가지 기준을 적용하는 것은 문법구조 이해 및 품사 분류를 어렵게 한다. 또한 한 영 기계번역시 품사의 불일치로 전처리가 필요하다. 이러한 문제를 해결하기 위하여 본 논문에서는 하나의 기준을 적용하여 품사를 분류하였다. 방법으로 한국어 표준문법에 의하여 말뭉치에 태깅하고 문제점을 찾아내며, 새로운 기준에 의하여 품사를 분류하였다. 본 논문에서 분류된 품사는 한국어 문장에서 통사적 역할이 동일하고, 영어에서의 사전 품사와 동일하며, 품사 분류의 모호성을 제거하고, 한국어의 문장 구조를 명확히 표현한다. 또한 한ㆍ영 기계번역시 패턴 매칭에 의한 목적언어 생성이 가능하게 한다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.137-140
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• 2003

Recently, as the demand of small-sized precision parts is rising in precision industry such as mobile, automobile, optic. etc. the requirement of small-sized machine tool is increasing. Desktop machine tool define small-sized machine tool that is able to install in table. According to diminishing in size, Desktop machine tool is able to economize production cost by reducing work area and consuming electric power. But Desktop machine tool generates vibration in acceleration and deceleration modes by inertia force of moving part. Also vibration is generated when it move simultaneously two axis or three axis. Such generating vibration situation is reason of declining stiffness of machine tool structure because of smallizing in size. And this vibration has a large effect on precision of machining products. Therefore, evaluating of the control characteristic is necessary for minimizing vibration of machine tool as much as possible to accomplish precision machining of small-sized parts

• 산업경영시스템학회지
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• 제19권37호
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• pp.63-70
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• 1996

This paper presents a model which may be used in optimal control of the Man-Machine systems in the aspect of information transmission. For this, we divided information into human parts and machine parts, and consider minimum error principle as a machine operating logic. Furthermore, we take the maximum information principle as a human information operating logic. This can be done in considering the Fisher Information and its transformed type, information inequality.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2005년도 춘계학술대회 논문집
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• pp.209-215
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• 2005

The dimensions and forms of precise machined parts are different to kinds of machine. It will be variant according to machine wear, tool form, cutting method and cutting condition at the same machine. At that time, the most important things are controlled and measured by appropriate measuring instruments. This paper aims to contribute to improving measurement accuracy through evaluation and consideration about various roundness in the machining company.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.121-124
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• 1996

In general, cellular manufacturing system can be constructed by the following two steps. The first step forms machine cells and part families, and the second step determines cell layout based on the result of first step. Cell layout has to be considered when cell is formed becauese the result of cell formation affects it. This paper presents a cell formation algorithm and proposes an integrated mathematical model for cell formation and cell layout. The cell formation algorithm minimizes the number of exceptional element in cellular manufacturing system. New concept for similarity and incapability is introduced, based on machine-operation incidence matrix and part-operation incidence matrix. One is similarity between the machines, the other is similarity between preliminary machine cells and machines. The incapability identifies relations between machine cells and parts. In this procedure, only parts without an exceptional element are assigned to machine cell. Bottleneck parts are considered with cell layout design in an integrated mathematical model. The integrated mathematical model determines cell layout and assigns bottleneck parts to minimize the number of exceptional element and intercell moving distance, based on linearixed 0-1 integer programming. The proposed algorithm is illustrated by using numerical examples.

• 산업공학
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• 제12권3호
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• pp.395-400
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• 1999

Shipbuilding process is composed of hull construction, in which the structural body of a ship is formed, and outfitting, in which all the non-structural parts such as pipes, derricks, engines, machinery, electrical cable, etc. are manufactured, added and assembled. Hull construction can be classified into parts fabrication, block assembly and hull erection. Among them, the parts fabrication is the first manufacturing stage that produces components or zones needed for block assembly and hull construction. More specifically, the parts fabrication is performed through machining processes including marking, cutting, pressing, and/or forming. When material is entering into the parts fabrication stage, it is important for achieving the total efficiency of production to select one of production division, so-called 'bay,' as well as machine tools on which the part is fabricated. In this paper, given production quantities of parts in the fabrication stage, the problem is to optimally select machine tools and production division, such that the total flow-time is minimized as well as the workload among machines is balanced. Specifically, three mathematical models for flow-time minimization, load balance, and simultaneously considering both objectives, and a numerical example are analyzed and presented.