비디오 트랜스포머 연구 동향

조현중 한국전자파학회 2023 전자파기술 Vol.34 No.5

Guaranteed Dynamic Priority Assignment Schemes for Real-Time Tasks with (m, k)-Firm Deadlines

조현중,정용화,박대희 한국전자통신연구원 2010 ETRI Journal Vol.32 No.3

We present guaranteed dynamic priority assignment schemes for multiple real-time tasks subject to (m, k)-firm deadlines. The proposed schemes have two scheduling objectives: providing a bounded probability of missing (m, k)-firm constraints and maximizing the probability of deadline satisfactions. The second scheduling objective is especially necessary in order to provide the best quality of service as well as to satisfy the minimum requirements expressed by (m, k)-firm deadlines. We analytically establish that the proposed schemes provide a guarantee on the bounded probability of missing (m, k)-firm constraints. Experimental studies validate our analytical results and confirm the effectiveness and superiority of the proposed schemes with regard to their scheduling objectives.

서로 다른 진화 특성을 가지는 부집단들을 사용한 새로운 하이브리드 진화 프로그래밍 기법과 카메라 보정 응용

조현중,오세영,최두현 대한전자공학회 1998 電子工學會論文誌, C Vol.c35 No.9

실수형 최적화 문제의 전역 최적해를 빠르고 정확하게 찾을 가능성을 높이기 위해, 서로 다른 진화특성을 가지는 여러 부집단들을 사용한 새로운 하이브리드 기법이 제안된다. 제안된 알고리듬은 세 개의 부집단을 사용하는데, 복잡한 적합도 함수를 가지는 문제에서 좋은 성능을 보이는 NPOSA 알고리듬이 두개의 부집단에 적용되고, 진화 방향과 크기가 조절되는 자기 적응 진화 알고리듬이 나머지 하나의 부집단에 적용되었다. 각 부집단들은 서로 다른 방법으로 진화하며 부집단들간의 상호교류를 통해 전역 최적해로 빠르게 도달하게 한다. 이 기법의 효율성은 몇 개의 표준 테스트 문제들을 사용하여 검증하였다. 마지막으로, 제안한 알고리듬이 실제 문제에 적용 가능함을 보이기 위해 카메라 파라메터의 최적값을 찾는 문제에 적용하였다. 보정 블럭에서 측정된 특징점들을 사용하여 오차 함수를 정의한 후, 하이브리드 방법이 그 오차 함수를 최소화하는 카메라 파라메터의 값을 찾을 수 있음을 보였다. A new hybrid technique using several sub-populations having completely different evolutionary behaviors is proposed to increase the possibility to quickly find the global optimum of continuous optimization problem. It has three sub-populations. Two NPOSA algorithms showing good performance in the problem having a rugged fitness function are applied to two sub-populations and a self-adaptive evolutionary algorithm to the other sub-population. Sub-populations evolve in different manners and the interaction among these sub-populations lead to the global optimum quickly. The efficiency of this technique is verified through benchmark test functions. Finally, the algorithm with three sub-populations has been applied to seek for the optimal camera calibration parameters. After an error function has been defined using measured feature points of a calibration block, it has been shown that the algorithm searches for the camera parameters that minimize the error function.

강소성 유한요소법을 이용한 Ti 합금 터빈디스크의 단조공정 해석

조현중,박종진,김낙수 대한기계학회 1994 대한기계학회논문집 Vol.18 No.11

The characteristics and good corrosion resistance at room and elevated temperatures led to increasing application of Ti-alloys such as aircraft, jet engine, turbine wheels. In forging of Ti-alloy at high temperature, die chilling and die speed should be carefully controlled because the flow stress of Ti-alloy is sensitive to temperature, strain and strain-rate. In this study, the forging of turbine disk was numerically simulated by the finite element method for hot-die forging process and isothermal forging process, respectively. The effects of the temperature changes, the die speed and the friction factor were examined. Also, local variation of process parameters, such as temperature, strain and strain-rate were traced during the simulation. It was shown that the isothermal forging with low friction condition produced defect-free disk under low forging load. Consequently, the simulational information will help industrial workers develope the forging of Ti-alloys including 'preform design' and 'processing condition design'. It is also expected that the simulation method can be used in CAE of near net-shape forging.

레이저 카메라를 이용한 용접선의 추적

조현중,류현,오세영 제어로봇시스템학회 1996 제어로봇시스템학회 국내학술대회 논문집 Vol.1 No.10

저온 대기압 플라즈마 제트를 이용한 근관 치료연구

조현,김윤중,한국희,김중길,김연정,강경훈,백구연,조광섭 한국진공학회 2017 한국진공학회 학술발표회초록집 Vol.2017 No.2

개정문화재보호법 해설 - '99년 1월 ~ 2001년 9월 기간 개정사항

趙顯重 국립문화재연구원 2001 헤리티지:역사와 과학 Vol.34 No.-

The purpose of this document is to explain the revisions of the Protection of Cultural Properties Act and its sub-laws which have been mad from Jan. 1999 to Sep. 2001. The Protection of Cultural Properties Act and its sub-laws have been revised three limes from 1999 to 2001, before and after the Office of Cultnral Properties was raised to Cultural Properties Administration on May 24, 1999. The main points of the revisions are as follows First of all, the role of the local autonomous entities has been increased. The governor of the local autonomous entities is entitled to announce administrative orders related to the preservation of State-designated Cultural Properties. Also, the local autonomous entities has the authorities to examine whether the construction work which will be made in the outer boundaries, which is provided by regulations, of the protected area of the cultural properties might have any effect on preservation of cultural properties or not. Second,preventive actions to protect the cultural properties have been strengthened. If the scale of construction work is more than some scale, the preliminary survey of the surface of the earth to confirm the existence of buried cultural properties and their distribution is obligated. One who is promoting the development plan more than some scale must discuss the plan with the Administrator of Cultural Properties Administration in rhe process of planning. These actions would be effcetive to prevent the cultural properties from being damaged because of the development. Third, relaxation of the restrictions has been proceeded. On the basis of regulations which specify the actions to affect the preservation of cultural properties, negative system that does not limit the actions which are not specified in the regulations is introduced. The appropriateness of both protected structure and area should be regularly reviewed and adjusted. Also, most of the restrictions which was made only for administrative convenience and over-regulated the people's living have been revised. Finally, the number of cultural properties to be protected has been increased. Besides the State-designated Cultural Properties, ihe other cultural properties which are worthy to be protected as City-or-Province-designated Cultural Properties can be designated provisionally and protected. The system of registration and maintenance of the buildings and facilities which are not designated as the Modern Cultural Heritages is established. The penalty for damaging and stealing the cultural Properties which are not designated to be protected was strengthened. Even a dead natural monument can be acknowledged as an natural monument and it is limited to make a specimen or stuffing of the dead natural monument. All of these actions are fit to the high level of understanding of the public about the cultural properties and as the result of these actions, the number of cultural properties to be preserved has been increased. To sum up, the directions of revisions of the Protection of Cultural Properties Act and its sub­laws which have been made from Jan. 1999 to Sep. 2001. are the localization of the protection of the cultural properties, the strengthening of protective actions, the relaxation of various regulations and the increasing of the number fo the protected cultural properties. Also, various problems raised in the processes of implementations of the laws have been reviewed and revised.

열간압연시 미세조직 예측을 위한 유한요소 모델

조현중(Hyunjoong Cho),김낙수(Naksoo Kim) Korean Society for Precision Engineering 1997 한국정밀공학회지 Vol.14 No.9

열간압연중 발생하는 미세조직 변화에 관한 연구

조현중(Hyunjoong Cho),김낙수(Naksoo Kim) 한국소성가공학회 1995 한국소성가공학회 학술대회 논문집 Vol.1995 No.10

개선된 Observe 기법을 적용한 Particle Filter 물체 추적

조현중(Hyun-Joong Cho),이철우(Chul-Woo Lee),정재기(Jae-Gi Jung),김진율(Jin-Yul Kim) 대한전기학회 2009 정보 및 제어 심포지엄 논문집 Vol.2009 No.5

In object tracking based on the particle filter algorithm controlling the proper distribution of the samples is essential to accurately track the target. If the samples are spread too wide compared to the target size, the tracking accuracy may degrade as some samples can be caught by background clutters that is similar to the target. On the other hands if the samples are spread too narrow, the particle filter may fail to track the abrupt motion of the target. To solve this problem we propose an improved particle filter that adopts "re-weighting" technique at the observe step. We estimate the distribution of the weights of the current samples by its mean and variance. Then the samples are re-weighted so that the appropriate distribution of the samples in proportional to the target scale is obtained at the next select step. The proposed tracking method can avoid convergence to local mean and improve the accuracy of the estimated target state.