Large-Scale TSP 근사해법에 관한 연구

유형선,김현승,Yoo, Hyeong-Seon,Kim, Hyun-Sng 한국정밀공학회 1992 한국정밀공학회지 Vol. No.

In this paper an approximate solution method for the large-scale Traveling Salesman Problem (TSP) is presented. The method starts with the subdivision of the problem domain into a number of cluster by considering their geometric characteristic. Each cluster has a limited number of nodes so as to get a local solution. They are linked go give the least pathe which covers the whole domain and become TSPs solution with start-and end-node. The approximate local solution in each cluster are obtained based on geometrical properties of the cluster, and combined to give an overall approximate solution for the larte-scale TSP.

CAVITATION EXPERIMENTS USING A HYBRID JOURNAL BEARING TESTRIG

유형선(Hyeong Seon Yoo) 대한설비공학회 1983 대한설비공학회 강연회 및 기타간행물 Vol.- No.-

고무차륜형 AGT 주행장치의 구조 및 피로해석

유형선(Hyeong Seon Yoo),권혁수(Hyok Soo Kwon),윤성호(Seong Ho Yun) 한국철도학회 1999 철도저널 Vol.2 No.2

Two representative types of the AGT (Automated Guideway Transit) system, which are bogie and steering types, are available for the side-guided system. Each system primarily consists of the bogie frame, suspensions, wheelsets and axles, braking system and transmission system. Among these components, the bogie frame is one of the most significant components subjected to the whole vehicle and passenger loads. This paper describes structural analyses and associated fatigue analyses for each bogie frame depending on the various loading conditions on a basis of the railway vehicle code UIC 515-4. Subsequently, comparisons are made between those two types to estimate which type is more reliable in terms of strength and fatigue. It is observed that the bogie type is a little advantageous over the steering one from the strength analysis. However, the two types are found to be in a reliable range of fatigue even though a realistic fatigue load case is further carried out. In addition, an optimal size of thickness is suggested for designs of the bogie frame.

[論文] 복합 저어널 베어링 실험장치를 이용한 캐비테이션 연구

유형선(Hyeong Seon Yoo) 한국자동차공학회 1985 오토저널 Vol.7 No.1

윤활에서 캐비테이션 문제는 가장 오래된 것중의 하나이며, 현재 많이 사용되고 있는 레이놀즈 경제조건(캐비테이션)은 유 막내의 인장력발생가능성 때문에 그 진실성이 문제되고 있다. 본 논문에서는 복합 저어널 베어링 실험장치를 이용하여 그 가능성이 연구되었다. 이 장치에서 측정된 최저 압력은 -7바 정도였으며 베어링 축회전수에 따라 캐비티가 발생하지 않는 안정영역, 불안정한 음압력 및 캐비터가 존재하는 영역과 두 영역 사이의 천이영역으로 구분할 수 있었다.

Large-Scale TSP 근사해법에 관한 연구

유형선(Hyeong-Seon Yoo),김현승(Hyun-Sng Kim) Korean Society for Precision Engineering 1992 한국정밀공학회지 Vol.9 No.3

Pollution 오차를 이용한 요소생성에 관한 연구

유형선(Yoo Hyeong Seon),편수범(Pyun Soo Bum) 한국철도학회 1999 철도저널 Vol.2 No.3

In this paper, made was a study on a mesh generation method based on the pollution error. This method is designed for the control of the pollution error in any patch of elements of interest. It is a well-known fact that the pollution error estimates are much more than the local one. When the pollution error is significant, nothing can be said about the reliability of any estimator based on local computations in the patch. Reliable a posteriori error estimation is possible by controlling the pollution error in the patch through proper design of the mesh outside the patch. This design is possible by equally distributing the pollution error indicators over the mesh outside the patch. The mesh generated from the conventional feedback pollution-adaptive mesh generation algorithm needs many iterations. Therefore, the solution time is significant. But the remeshing scheme in the proposed method was used here. It was shown that the pollution-adaptive mesh improves the E.I., simply denoted as Effectivity Index, on the patch of interest, and the pollution error reduces less than the local error.

고무차륜형 AGT 주행장치의 진동피로해석

유형선(Hyeong-Seon Yoo),윤성호(Seong-Ho Yun),변상윤(Sang-Yun Pyun),편수범(Soo-Bum Pyun) 한국철도학회 2000 철도저널 Vol.3 No.3

The rubber wheel-type AGT has two major kinds of bogie; one is the bogie type and the other steering one. Both are important vehicular structure to support the whole running vehicle and passenger loads. This paper deals with the static analysis for the two types of bogie frame subjected to combined external forces, as well as independent ones specified in UIC 515-4. Furthermore, the dynamic analysis is performed under vibrational loading conditions so as to compare dynamic characteristics, Numerical results by using commercial packages, I-DEAS and NASTRAN show that maximum stresses do not exceed the yield strength level of material used for both bogies. From an overall viewpoint of strength, the bogie type turns out to be superior to thc steering type except for the case of a lateral loading. It is also observed that the steering type shows a characteristics of low frequency behavior during a course of searching for structurally weak areas to bc stiffened. The vibrational fatigue analysis for each bogie frame depends on the loading time history conditions which is applied Time History Central Database List in the NASTRAN package. Subsequently, the fatigue life of bogie type is longer than the steering type.

개인정보보호 강화를 위한 동적 보안수준 결정

장인주(In Joo Jang),유형선(Hyeong Seon Yoo) 한국전자거래학회 2012 한국전자거래학회지 Vol.17 No.1

사회적요구와 기술 개발로 체계적인 개인정보관리와 보안 지침강화에도 불구하고, 개인정보 유출과 침해의 문제는 다양한 형태로 나타나고 있다. 이러한 개인정보를 관리함에 있어, 어떠한 정보를 보호할 것인가 하는 문제는 민감한 핵심 요소이다. 본 논문에서는 개인정보를 구성하는 각 속성정보의 관리 정책을 결정할 기준으로 속성정보의 동적 보안수준 측정법을 제시한다. 동적 보안수준 측정법은 개인정보의 가변적 특성을 측정 요소로 채택한다. 이 기법을 적용함으로, 개인의 각 속성정보 보안수준의 변화에 능동적으로 대처할 수 있는 정보관리 기능을 제공할 수 있다. 이는 기존 정보관리기법의 보안성을 더욱 높일 수 있으며, 통합 ID 관리 시스템이나 전자지갑과 같은 통합 시스템의 보안성 향상에 기여할 것으로 기대된다. For social demand and technological development, systematic private information management and security guidance have been enhanced; however, the issue of leakage and invasion of private information is shown in many ways. In the management of such private information, the issue of how to protect such information is one of the sensitive key elements. As a criterion to decide the management policy of each property information consisting of private information, this article suggests Dynamic-Security-Level-Measurement for property information. DSLM adopts the variable characteristics of property information as the element of measurement. By applying this method, it is possible to provide information management functions to cope with the changes of each property information security level of an individual actively. It is expected that this will improve the security of previous information management methods even more and also contribute to the improvement of security in integrated systems such as the integrated ID management system and electronic wallet.

[구조강도부문] ZZ-SPR을 이용한 Pollution Error의 추정에 관한 연구

편수범(Soo-Bum Pyun),유형선(Hyeong-Seon Yoo) 한국자동차공학회 1999 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

In this study we focus on the estimation for the pollution error by using ZZ-SPR. simply denoted as Zienkiewicz & Zhu Superconvergent Patch Recovery. The error resulted from the conventional error estimators is equivalent to the local error. Moreover. in the case of unsmooth solution problem with a polygonal domain such as L-shape. the local error estimates are much smaller than the pollution error ones. Therefore. the estimation of the pollution error as well as the pollution adaptive mesh has a large effect on the accuracy of the solution. Thus we use the ZZ-SPR for estimating the pollution error. Subsequently. we emphasize on the necessity for calculation of the pollution error by comparing the pollution error estimate with the local one.

고무차륜형식 경전철(AGT) 대차의 구조해석 및 주파수 응답해석

변상윤(Byun Sang-Yun),유형선(Yoo Hyeong-Seon),윤성호(Yun Seong-Ho) 한국철도학회 1999 한국철도학회 학술발표대회논문집 Vol.- No.-

Rubber wheel-type AGT has two major kinds of bogie; one is the bogie type and the other and passenger loads. This paper deals with the statics analysis for two types of bogie frame subjected to combined external forces, as well as independent ones specified in DIC 515-4. Furthermore, the dynamics analysis is performed under vibrational loading conditions so as to compare dynamic characteristics, Numerical results by using commercial packages, I-DEAS and NASTRAN show that maximum stresses do not exceed the yielding level of material used for both bogies. From an overall viewpoint of strength, the bogie type turns out to be superior to the steering type except the case of a lateral loading. It is also observed that the steering type shows a be stiffened. It is strongly anticipated that vibrational fatigue analysis should be carried out under realistic loading conditions closely matching to situations such as running surface and lateral clearances along the guideway.