• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.109-114
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• 2007

Analytical method to analyze the effect of tolerance on the modal characteristic of multi-body systems in dynamic equilibrium position is suggested in this paper. Monte-Carlo Method is conventionally employed to perform the tolerance analysis. However, Monte-Carlo Method spends too much time for analysis and has a greater or less accuracy depending on sample condition. To resolve these problems, an analytical method is suggested in this paper. By employing the sensitivity information of mass, damping and stiffness matrices, the sensitivities of damped natural frequencies and the transfer function can be calculated at the dynamic equilibrium position. The effect of tolerance on the modal characteristic can be analyzed from tolerance analysis method.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1994년도 춘계공동학술대회논문집; 창원대학교; 08월 09일 Apr. 1994
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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.

• 한국GIS학회:학술대회논문집
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• 한국GIS학회 2008년도 공동추계학술대회
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• pp.195-199
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• 2008

본 논문은 택시들의 승차율을 높이고 승객들의 대기시간을 최소화하기 위하여 제주 택시들의 이동이력 데이터를 기반으로 하여 공차들을 승객을 만날 가능성이 많은 지역으로 배치하는 기법을 제시한다. 이동이력 데이터에 포함된 공차 보고와 승차 보고 수 사이의 스케일 차이를 극복하기 위하여 전체수와 영역내 합에 대한 비율로 정규화하는 방법을 설명하고 장단점을 분석한다. 또 시간대별, 요일별, 주간별 택시들의 승객 대기시간에 대한 통계 데이터에 기반하여 가장 수요와 공급이 적정하게 유지되는 시간구간을 발견하고 이 구간에 대한 택시 분포와 현재의 택시 분포의 차이에 의해 수요보다 공급이 많은 곳의 택시를 재배치한다.

• 항공우주기술
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• 제3권2호
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• pp.20-24
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• 2004

본 논문에서는 위성용 전자 장비 장착을 위한 인서트의 형태/위치 공차 해석법에 대해 기술한다. 위치 공차를 구하기 위해 순차적 이차 계획법이 사용되었으며, 예제로 다목적 실용위성 2호기 STM(Structure and Thermal Model)의 RDU(Remote Drive Unit)와 OBC(On-Board Computer)의 장착 경우를 해석하였다.

• 대한기계학회논문집A
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• 제21권5호
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• pp.859-869
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• 1997

In this paper, the robust design and tolerancing of the stabilized mirror is performed to increase its stabilization performance under vehicle vibration. Based on the sensitivity analysis, the seven important control factors are first identified, and then the optimal as well as robust values in the sense of Taguchi method are obtained. Finally, the tolerances associated with each design variables are determined based on a successive sensitivity analysis of the simulated system response so that the deviation in the response from the target value meets the specification requirements. The proposed tolerancing method features that it is a robust but conservative design method and that the computational effort is much less than the Monte Carlo simulation method.

• 대한기계학회논문집
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• 제18권9호
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• pp.2257-2264
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• 1994

A method to evaluate the position performance for a stochastically defined planar robot manipulator is presented. Performance is defined as the operational reliability based upon the positional errors of the manipulator tip. An analytical method is developed and applied to a two-link robot manipulator through forward kinematics. This study includes uncertainties in the link length, pin center location and radial clearance. By virtue of the effective link length model, only the nominal manipulator model and statistical information on the uncertainties are required. The results from the analytical method is compared to those from the Monte Carlo simulation.

• 대한기계학회논문집A
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• 제27권6호
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• pp.905-913
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• 2003

Generally, most of optimization have been performed with fixed sizes and variables. But, the optimum value considering tolerance of design variables and material properties, might be useless owing to exist in infeasible region. It is needed that the tolerance of design variables and material properties is considered for a real design problem. A deterministic optimal solution can be in the feasible region by performing robust optimization considering tolerance. In the paper, robust design is suggested to gain an optimum insensitive to variation of design variables and it is applied for optimization problem of caliper disc brakes for vehicles.

• 대한기계학회논문집A
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• 제24권11호
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• pp.2672-2679
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• 2000

In synthesizing and RSSS-SC mechanism that is the kinematic model of the McPherson strut suspension system in automobiles, the design equations for R-S, S-S and S-C dyads should be solved separately for a given set of prescribed positions. The number of prescribed positions that the RSSS-SC mechanism can be synthesized is up to three because of the S-C dyad. This limitation may cause unsatisfactory results in synthesized joint positions. This paper presents a kinematic synthesis method to place the joints of an RSSS-SC mechanism in desired boundaries by varying the prescribed positions of the mechanism within acceptable tolerances. The sensitivity analysis of the joint positions is used determine which displacement parameter should be altered to fulfill this task.

• 대한기계학회논문집A
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• 제24권11호
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• pp.2713-2722
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• 2000

When designing a gear drive, designers should specify tolerances reasonably considering accuracy, cost, and manufacturing capability. In field design, however, designers mostly assign adequate tolerance without correlations between parts and assembly, resulting in iterative design dependent on experts know-how. In order to resolve this, the tolerance design system for a cylindrical gear drive is developed both to support tolerance design automation and to synthesize design processes of part and assembly tolerances. In this research, part tolerances are designed with the databases constructed by ISO, Ks, JIS and bearing catalogue, Assemble tolerance, that is, backlash tolerance is designed by synthesizing part design tolerances stochastically using the formulated assembly relations. This system can include part tolerance and fitting accuracy of shaft adn bearing in practical design. In addition, this system provides field-designers with a synthetic guideline for tolerance design of a gear drive.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.813-818
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• 1996

This paper presents a method for tolerance design using the Taguchi Method(TM) and general purpose mechanism analysis program. Also the tolerance design method is with respect to performance improvement of a mechanism. To use the orthogonal array, mathematical model of a mechanism is established and experiments are carried out by the general purpose mechanism analysis program. The contact model is used to consider a clearance effect. This method is applied to the tolerance design of the VTR Deck mechanism. This method can be used in tolerance design of general mechanisms.