• 정보화연구
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• 제11권4호
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• pp.441-448
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• 2014

최근 각 산업분야에서 공간정보의 구축은 물론 그 활용과 유통을 위한 다양한 노력들이 이루어지고 있다. 철도산업분야에서도 이러한 공간정보는 각 관련 주체간 협업 등을 원활하게 하고, 자산관리 및 철도운영 등의 효율성을 높일 수 있다. 본 논문에서는 철도공간정보의 체계적인 활용을 위해 철도공간정보에 대한 참조체계 방안을 제시하고자 한다. 현재 철도는 상대위치 개념을 중심으로 모든 시설물 관리와 차량운행이 이루어지고 있다. 상대위치 기반의 관리체계는 많은 장점을 가지고 있으나, 선로 개량 등으로 선형 변화가 발생할 경우 변경된 지점을 중심으로 그 다음 위치들은 모두 상대위치를 변경하여야만 하는 어려움 또한 유발된다. 그리고 토목, 전기, 신호 등 철도의 각 분야에 속한 시설물들은 각각 다른 상대위치를 가지고 있기 때문에 협업의 어려움 또한 발생하고 있다. 이러한 문제점을 해결하고, 철도산업 이외의 분야와 협업 및 정보 융복합 등을 위하여 절대위치 기반의 철도공간정보참조체계가 필수적이다. 이에 본 연구에서는 세계적으로 유일한 객체식별자를 가지는 OID표준을 기반으로 철도공간정보참조체계 식별자 ROID(Railway Object IDentifier)와 시스템 확장성 및 연계성이 높은 서비스 객체지향형 철도공간정보참조체계를 제안한다. ROID는 기존의 철도 시설물 관리체계를 유지하면서 절대위치와 함께 유일한 식별자 개념을 가질 수 있도록 구성된다.

• The Journal of the Acoustical Society of Korea
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• 제15권3E호
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• pp.13-18
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• 1996

A real-time identifier for the nonstationary time-varying signals and systems was implemented using a low cost DSP (digital signal processing) chip. The identifier is comprised of I/O units, a central processing unit, a control unit and its supporting software. In order t estimate the system accurately and to reduce quantization error during arithmetic operation, the firmware was programmed with 64-bit extended precision arithmetic. The performance of the identifier was verified by comparing with the simulation results. The implemented real-time identifier has negligible quantization errors and its real-time processing capability crresponds to 0.6kHz for the nonstationary AR (autoregressive) model with n=4 and m=1.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.1073-1075
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• 1996

This paper presents a neuro fuzzy system(NFS) for implementing fuzzy inference system with a monotonic membership function. The modeling and control of a discrete nonlinear system using a NFS is described. The membership function parameters of a identifier and controller are adjusted by back-propagation algorithm. These identifier and controller is constructed to proposed NFS. A on-line identification and control are accomplished by this NFS. A controller is gived information of the system, that is variation of the system output according to that of the control input by a identifier. A controller makes control input in order to control discrete-time nonlinear system. A Simulation is presented to demonstrate the efficiency of a suggested method.

• 산업공학
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• 제20권2호
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• pp.227-234
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• 2007

The national product identifier(NPI) currently used in the national product asset management system does not accommodate ISO or EPC standards due to the limitation of tag memory. For this reason, we propose a new NPI which accommodates not only ISO item identification standards but also the memory capacity of ISO tags. First of all, memory structures of ISO/IEC 18000-6C and EPC tags are analyzed from the view point of product identifier structure. Second, ISO/IEC 15459 and EPC identification standards as item identifier structures for the product asset management are analyzed. Third, based on these analyses, the NPI used for the current RFID-based product asset management system is analyzed and its problems are presented. Finally, a new NPI structure is proposed suitable for ISO/IEC 18000-6C and ISO/IEC 15459.

• 대한전기학회논문지
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• 제43권4호
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• pp.543-552
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• 1994

This paper presents a decentralized quadratic regulation architecture with feedforward neural networks for the control problem of complex systems. In this method, the decentralized technique was used to treat several simple subsystems instead of a full complex system in order to reduce training time of neural networks, and the neural networks' nonlinear mapping ability is exploited to handle the nonlinear interaction variables between subsystems. The decentralized regulating architecture is composed of local neuro-controllers, local neuro-identifiers and an overall interaction neuro-identifier. With the interaction neuro-identifier that catches interaction characteristics, a local neuro-identifier is trained to simulate a subsystem dynamics. A local neuro-controller is trained to learn how to control the subsystem by using generalized Backprogation Through Time(BTT) algorithm. The proposed neural network based decentralized regulating scheme is applied in the power System Stabilization(PSS) control problem for an imterconnected power system, and compared with that by a conventional centralized LQ regulator for the power system.

• 정보관리학회지
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• 제21권3호
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• pp.15-29
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• 2004

정보통신 및 인터넷의 급속한 발전으로 기존의 불리적인 저작물이 디지털 콘텐츠로 급속히 전환되면서 디지털 콘텐츠 자원에 대한 접근 및 서비스 방식과 기존의 식별기호로는 디지털 콘벤츠의 특성을 충족시키는 석별이 미흡하고 한계가 있다 또한, URN 명세를 만족하는 DOl 식별체계도 저널, 회의자료와 같은 학술잡지형태에만 활용되고 있어 다양한 형대의 비학술잡지에 적용할 식별체계가 필요하다. 따라서, 해외 주요 디지털 콘텐츠 서비스기관의 식멸체계 활용사례와 KISTI에서 소장하고 있는 학술잡저 형태 2종, 비 학술잡지 형태 3 종 등 5종을 분석하여 학술잡지뿐만 아니라 비학술잡지에도 적용할 수 있는 고유 식별기 호를 개발하고, 고유 식별기호 기반의 전자원문 연계시스템을 설계 및 구현하고자 한다.

• Journal of Electrical Engineering and information Science
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• 제2권3호
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• pp.61-65
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• 1997

This paper proposes an intelligent controller for brushless DC motor and load with unknown nonlinear dynamics. The proposed intelligent control system consists of a plant identifier and PID controller with varying gains. The identifier is constructed using an Auto Regressive Moving Average (ARMA) model. In order to tune the parameters of the identifier and the gains of the PID controller efficiently, e also propose a modified Evolution Strategy. Experimental results show that the proposed intelligent controller for brushless DC motor has good control performance under unknown disturbance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 B
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• pp.776-778
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• 1999

In this paper, identifier for thermal storage system using multi-layer feedforward neural network (MFNN) is designed. It is very difficult to control thermal storage system, since thermal storage system is nonlinear and its time constant is very large. Thus, in the MFNN, delta-bar-delta algorithm for high running speed and 2-bit status input are used. Also hardware using microprocessor for identifier is developed. The experimental results indicate that the proposed method can predict temperature more accurately.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.927-930
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• 1992

VSS identification approach is based on following concept, i.e. while in sliding motion, the switching of control inputs refects system uncertainites. Therefore, if there exist some operations that make the information form the switiching control inputs be achievable, then the unknown parameters can be actually identification mechanisms which can fully make use of the available information. Two different types of VSS identifiers are taken into consideration. The first type uses adjustable model whose structure is similar to that of identified systems. From the viewpoint of contro, this type of VSS identifiers may be regraded as direct identifier vecause the identified system is handled as an open loop. On the other hand, if the identified system is controlable in the sense of VSS(sliding mode can be generated through chosing control inputs), the second type of VSS identifier, the indirect VSS identifier, can be constructed according to the linerized system strucutre while staying in sliding mode. Therefroe it can be applied to some nonlinear systems which are not linear in parametric space by general identification algorithms, whereas linear in parametric space when sliding mode is existed.

• 동력기계공학회지
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• 제9권4호
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• pp.194-201
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• 2005

In this paper, we propose an adaptive mechanism based on humoral immune algorithm and neural network identifier technique. It is also applied for an autonomous guided vehicle (AGV) system. When the immune algorithm is applied to the PID controller, there exists the case that the plant is damaged due to the abrupt change of PID parameters since the parameters are almost adjusted randomly. To slove this problem, we use the neural network identifier technique for modeling the plant humoral immune algorithm (HIA) which performs the parameter tuning of the considered model, respectively. Finally, the experimental results for control of steering and speed of AGV system illustrate the validity of the proposed control scheme. Also, these results for the proposed method show that it has better performance than other conventional controller design method such as PID controller.