비선형성을 가진 직류 전동기의 고장 검출 진단 : A Neural Network based Multiple Observer Scheme

이기상,류지수 단국대학교 1998 論文集 Vol.32 No.-

A Fault Detection and Isolation (FDI) Scheme for a class of nonlinear systems is proposed and applied to design fault detection system for a DC motor with nonlinear characteristics. The proposed FDI scheme consists of an observer bank, a simple residual generation algorithm, and an artificial neural network for fault isolation. Gain scheduled observers, each of which is able to cope with nonlinearities, are employed to generate residuals that will be further processed to detect and to isolate the faults. Observer gains are tuned by trained artificial neural networks so that observer poles are invariant over all operating points. Another well trained ANN is employed for fault isolation and/or diagnosis. The type of faults in the motor application is parametric one which is difficult to treat with conventional FDI schemes. Simulation results show the applicability of the FDI scheme to a class of nonlinear systems including DC motors.

질량의 최적 배치에 의한 구조물 진동 감소 연구

申龜秀,李祺形,朴泰圓,鄭寅聖 全北大學校 1996 論文集 Vol.42 No.-

In this paper, a theoretical optimization approach is presented in order to consider natural frequencies for vibration transmitted to the fuselage. Also, this paper describes methods for reduction of structural vibration by the optimal placement of masses for formal mathematical optomization techniques. An optimization procedure is developed which employs the tuning masses and corresponding locations as design valiables which are systematically changed to achieve low values of shear without a large mass penalty. Three optimazation strategies are developed and tested. The first is based on minimizing the modal shaping parameter which indirectly reduce the modal shear amplitudes corresponding to each harmonic of airload. The second strategy reduces these amplitudes directly and the third strategy reduces the shear as a function of time during a revolution of the blade.

GSP를 이용한 기하교육의 학습효과 : 중학교 2학년을 중심으로 In the Center of the Second Grader in Middle School

정기수,정권수 순천대학교 1999 순천대학교 자연과학논문집 Vol.18 No.2

For the purpose of making up some problems of geometry education, I want to show many visual and graphic models of diagrams by introducing GSP, which is one of software in computer class, before introducing proof in the second grade of middle school and to see what kinds of learning effects there are by permitting students to do research by themselves. To do this, I made an experiment by dividing two group of students as a experimental and comparing classes, and the result is as follows. First, the computer using-class was more effective than the usual ones in increasing scholastic achievements. Second, there are no difference between the experimental and comparing class. And also both group students felt difficulty in proving. This may show that more sufficient and effective learning about diagrams is needed before introducing proof.

용융 AI-10Si 합금의 산화피막강도 및 표면 미세조직에 미치는 Mg첨가의 효과에 관한 연구

김길수,양중식,김기주,백영남 慶熙大學校 材料科學技術硏究所 1992 材料科學技術硏究論集 Vol.5 No.-

This study was carried out to determine the strength of oxide skins of Al-10Si alloy melts and the effect of Mg addition on the morphology of oxide skins as the practical alloy for automobile piston. This has been observed by Rotational Die Movement Equipment for the temperature range from 600℃ to 720℃, the oxidation time range from 2 min. to 60 min. and the Mg weight percent(wt %) range from 1% to 5%. As the surface temperature and the surface oxide time of alloy melts increased, the crystalization of oxide layer and the creation of oxides were verified.

효율적인 제약만족문제 처리를 위한 유사최소신장 2-트리의 도입 및 적용

李基哲,姜水蓮 弘益大學校 科學技術硏究所 1994 科學技術硏究論文集 Vol.4 No.-

A constraint satisfaction network is a knowledge representation method suitable for representing problems which must satisfy many constraints between variables. Backtracking is basically used to solve a constraint satisfaction problem with finite domains, and many intelligent backtracking schemes have been developed up to now. This paper is about backtracking performance improvement for solving constraint satisfaction problems. First of all, the concept of complete minimum spanning 2-tree is introduced, and its practical version quasi minimum spanning 2-tree is defined and applied to 8-queens problem. In addition, dynamic variable ordering is further applied. The test results show substantial reduction of backtrackings. 2-tree based approach may be applied to more realistic problems in the near furture.

시멘틱 웹 기반의 비교구매 에이전트를 위한 동적 웹 온톨로지 시스템에 대한 연구

김수경,안기홍 한밭대학교 정보통신전문대학원 2005 정보통신전문대학원 논문집 Vol.3 No.1

기존 전자상거래 플랫폼과 컨텐츠는 데이터의 확장 및 통합이 고려되지 않은 HTML을 중심으로 한 표현 기반 기술로 되어 있고, 특히 전자상거래 사이트별로 상품 정보에 대한 분류체계가 상이함으로 인해 구매자에게 상품별 비교와 검색에 있어서 많은 시간이 낭비되고 또한 정보의 공유가 어려운 기술로 인하여 판매자와 구매자 모두의 요구를 만족시키지 못하고 있다. 본 논문에서는 최근 차세대 웹 기술로 각광받고 있는 시맨틱 웹 기반 기술인 RDF/RDFS를 이승하여 기존 이종의 상점에 제시된 상품 정보를 RDF 문서로 생성하고, Web Ontology Language(OWL)를 사용하여 상품 지식 기반 온톨로지를 구축한 뒤, RDF 문서와의 분석과 매칭을 통하여 이종의 상점에 표현된 상품을 실시간으로 비교 검색하고 동적으로 상품에 대한 지식 기반 온톨로지를 생성하는 웹 온톨로지 시스템을 설계 제안하였다. The existing e-commerce platform and contents are made of expression-based technology HTML that expansion and integration of data weren't considered. Besides, a lot of time is wasted in comparison and a retrieval of product to a buyer, because a classification System about product information is different every electronic commerce site, and cannot satisfy demand of seller and buyer all by trouble of information sharing an technology. In this paper, use the RDF/RDFS which is Semantic Web-based technology to get attention with next generation Web technology recently and it generates product information of the existing store in a RDF document, and after use OWL, and establishing product knowledge-based ontology, and through analysis and matching with a RDF document, A design proposed a System that compare a product expressed to an each e-commerce site by real time, and to retrieval and redefine product knowledge-based ontology as dynamic.

웹 캐스팅과 활용 방안

김인수,김기천 건국대학교 산업기술연구원 2000 건국기술연구논문지 Vol.25 No.-

웹 캐스팅(Web Casting)은 인터넷 상에서 의사소통의 새로운 혁신으로 꼽히고 있다. 웹 캐스팅은 인터넷방송, 화상회의, VOD, 원격교육, 원격진료, 전자상거래 등에 응용될 수 있다. 이 논문에서는 웹 캐스팅의 개요와 현황을 알아보고, 웹 캐스팅 서비스에 사용되는 Push, Streaming, On-demand, Buffering 기술에 대해 고찰하며, 웹 캐스팅 시스템을 활용하는 방법을 연구한다.

GPS/GLONASS 위성항법시스템에 의한 차량의 이동궤적

이기부,이인수 영남이공대학 2001 論文集 Vol.30 No.-

Nowadays Multi-sensor such as GPS(Global Positioning System), GLONASS(GLObal Navigation Satellite System), CCD(Charge Coupled Device), IMU(Inertial Measurements Units), etc are integrated. And information about road, etc is acquired and the Digital Map is upgraded from these. Expecially, GPS in U.S.A is popular in the integrated land navigation system, and also GLONASS in RUSSIA is expected to play an important key as a complementary device of GPS, but now it is not working perfectly because of a life cycle and a budgetary deficit. So In this study, moving trajectory of vehicle with the integrated GPS/GLONASS satellite navigation system is measured. and as a result, it was shown that GLONASS play an important key in the navigation of vehicle.

냉동생지의 제조 및 최적 해동조건 연구

이수태,기해진,정순택,박양균 木浦大學校 工業技術硏究所 2000 工業技術硏究誌 Vol.10 No.-

Frozen dough of two flour, Tazo and Tazo-S, and two thawing, room and cold temperature, were determined to qualified bread quality. For best bread quality from frozen doughs, very strong flour should be used. Frozen doughs are increasingly being produced in the baking industry even though they generally provide bread with lower loaf volume than dose unfrozen fresh dough. Several investigators have reported that the major changes in doughs that have been frozen are related to yeast. During the dough fermentation, yeast produces carbon dioxide and flavor compounds. Loaf volume decreased markedly with freezing and thawing, and gradually during frozen storage.

동기발전기 여자시스템용 고주파 PWM 컨버터 설계

장수진,류동균,원충연,이진국,배기훈,김수석 성균관대학교 2003 학술회의지원논문목록집 Vol.2003 No.-

A synchronous generator is equipped with an automatic voltage regulator(AVR), which is responsible for keeping the output voltage constant under normal operating conditions at various levels. The output voltage of Synchronous Generator is regulated constantly by field voltage control in excitation system. High frequency PWM converter (Buck converter) type excitation system for synchronous generator that can sustain proper output voltage level even at the fault condition happened. The proper operation of the proposed excitation system was verified through the simulations and the experiments.