• 조명전기설비학회논문지
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• 제29권7호
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• pp.28-37
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• 2015

Owing to the variability of large-scaled wind power system, the development of wind farm management technologies and related compensation methods have been receiving attention. To provide an accurate and reliable output power, certain wind farm adopts a specified management system including a wind prediction model and grid expectation solutions for considering grid condition. Those technologies are focused on improving the reliability and stability issues of wind farms, which can affect not only nearby system devices but also a voltage condition of utility grid. Therefore, to adapt the develop management system, an expectation process about voltage condition of Point of Common Coupling should be integrated in operating system for responding system requirements in real-time basis. This paper introduce a grid imposing method for a real-time based wind farm management system. The expected power can be transferred to the power flow section and the required quantity about reactive power can be calculated through the proposed system. For the verification process, the gauss-seidel method is introduced in the Matlab/Simulink for analysing power flow condition. The entire simulation process was designed to interwork with PSCAD for verifying real power system condition.

• 한국컴퓨터정보학회논문지
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• 제17권2호
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• pp.167-176
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• 2012

본 논문은 장비엔지니어링 시스템(EES) 프레임워크에서 반도체와 광전자 제조장비를 위한 새로운 하이브리드 생산설비데이터 습득 시스템을 설계하고 구현한다. 장비엔지니어링 분야에서 장비로부터 수집되는 데이터 량이 급격히 증가하고 있다. 제안된 HEDAS(Hybrid Equipment Data Acquisition System)는 EES 프레임워크에서 발생하는 대용량의 실시간 데이터를 효율적으로 처리한다. 또한, 제안된 시스템은 실시간 EES 응용 뿐만 아니라 비실시간 EES 응용을 지원할 수 있다. 실시간 EES 응용을 위해서 HEDAS는 메모리 기반의 연속질의와 필터링 기술을 이용하여 고속의 실시간 처리를 수행한다. HEADS는 비 실시간 장비 데이터를 HEADS 기반의 데이터베이스 또는 기존의 데이터베이스에 선택적으로 저장할 수 있다. 특히, 급격하게 증가하는 장비 데이터에 대해 디스크 저장 비용을 절감하기 위해 타임스템프 기반의 압축 인덱싱과 질의처리 기법을 제공한다. HEDAS는 EES 프레임워크에서 대용량의 실시간 및 비 실시간 장비 데이터를 수집하여 다양한 EES 응용에 수집된 데이터를 전송할 수 있는 효율적인 시스템이다.

• 품질경영학회지
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• 제39권3호
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• pp.412-421
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• 2011

In this paper, we introduce Quality of Service(QoS) analytic model of a distributed system that decentralizes the process nodes performing each task and communicates through a network for cooperation. The model advances a service reliability model of Dai et a1.(2003) by means of considering the processing time. The service is assumed to be provided by a centralized heterogeneous distributed system which is composed of some subsystems managed by a control center. The QoS is defined as the probability that a service is provided successfully in an allowed time, we consider the hardware/software reliability and the processing time which include program execution time, data transfer time. We derive the processing time distribution for a required service through convolution of corresponding probability density function. An application example is used to explain the procedure of computing quality of service.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.231-231
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• 2000

It is proposed that a novel method which can compensate the time delay occurs in overall system, when voltage and current is measured, owing to LPF, hysteresis control inverter and microprocessor program computation time. The Proposed scheme estimates the time delay using the difference between Q-axis stator current command and time delayed Q-axis stator current in synchronous reference frame, and compensates the time delay of voltage and current using angular displacement of DQ transformation. The proposed scheme compensates accurately the time delay occurs in overall system. Therefore performance of vector control system is improved highly and it is verified by simulation and experiment.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(5)
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• pp.157-160
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• 2002

When the teleoperation system has a signal transmission time delay between slave system and control system, the position tracking performance of the slave system and system stability are likely to be deteriorated. This paper proposes a force reflecting position control scheme for teleoperation system with signal transmission time delay. The proposed scheme not only satisfy the system internal stability but also improves the position tracking performance with disturbance rejection capability. The simulation results show that the proposed control method provides excellent performances.

• 음성과학
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• 제3권
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• pp.119-131
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• 1998

We have developed a keyword spotting system for automatic speech editing. This system recognizes the only keyword 'MBC news' and then sends the time information to the host system. We adopted a vocabulary dependent model based on continuous hidden Markov model, and the Viterbi search was used for recognizing the keyword. In recognizing the keyword, the system uses a parallel network where HMM models are connected independently and back-tracking information for reducing false alarms and missing. We especially focused on implementing a stable and practical real-time system.

• 한국군사과학기술학회지
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• 제14권1호
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• pp.154-159
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• 2011

The effect of the ignition delay time gap is newly studied. The operational characteristics of the linked two pyrotechnic thrusters are affected by the time gap. Although two thrusters are simultaneously ignited, the time at which the pressure starts to rise in each thruster may not be synchronized. The characteristic of the system with the time gap is compared with that of the fully synchronized system without any time gap. Depending upon the magnitude of the time gap, the pressure-time profile and the ballistic performance are different. When two pyrotechnic thrusters have a time gap, the peak pressure of one thruster(in which the pressure is built up earlier) is increased and the other is decreased. As the time gap is increased, the peak pressure is converged into the maximum pressure. This maximum pressure can be obtained when only one thruster is activated. Because the maximum pressure is bounded, it is predicted that there isn't any catastrophic failures in the considered system. When the time gap is relatively small, the impulse of the combined force acting on the moving body is almost maintained. But the ballistic performance of the system with a large time gap should be carefully estimated because the reduction of the ballistic performance should not be easily neglected.

• 정보처리학회논문지A
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• 제8A권4호
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• pp.353-358
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• 2001

시스템 처리용량의 증가로 과거 메인프레임이 처리하던 작업을 PC가 처리할 수 있게 되었다. 특히 산업계에서는 기존의 메인프레임을 PC급으로 전환하면서 PC급 시스템에서 실시간성을 보장하는 실시간 정보처리와 실시간 정보감시를 위한 실시간 모니터링 기능이 요구되고 있다. 그러나 실시간성의 보장을 위해서는 실시간 기능의 추가 및 이에 대한 검증이 필요하다. 본 논문은 이러한 실시간성의 요구를 충족시키기 위해 실시간성을 제공할 수 있는 시스템의 구축과 이에 대한 성능 검증을 목적으로 한다. 또한 실시간 정보감시를 위해 웹기반의 실시간 모니터링 시스템을 구축하는 것을 목적으로 한다.

• 산업경영시스템학회지
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• 제14권24호
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• pp.149-154
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• 1991

The one of the important problems in the design of queueing systems is the decision of the order of service stations. The object of this problem is the decision of the order that minimizes the expected sojourn time per customer in the given arrival process and service time distributions. In this paper, the tandem queueing system in series is studied with the emphasis on the optimal order of the tandem queueing system which has three stations with single servers. In one system, customers arrive at the first station with Poisson process. This system is composed of service stations with a constant, a general distribution and a Exponential distribution is studied. To select the optimal order after the orders of each pair of two stations is decided, it is compared the two orders of system. With this results, total expected delay of the systems which has three stations is compared. The result is the best that service station with constant time is on the first place, then the service station with general distribution and the service station with Exponential distribution is followed. And the other system is consist of service stations with a constant and two probabilistic distributions. In this case, two probabilistic distributions has a non-overlapping feature. It is the optimal order that the service station with constant time is on the first place then the service station with longer service time and the service station with shorter service time is followed.

• 전기학회논문지P
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• 제52권3호
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• pp.121-126
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• 2003

In this paper, we propose the haptic system for the real-time virtual environment-control, which controls the sense of sight, hearing and touch. In order to maintain the stable haptic system in this study, we apply the proxy force rendering algorithm and the real-time graphic deformation algorithm based on the FEM. The applied proxy algorithm makes the system possible to be more stable and prompt with a virtual object. Moreover, the haptic rendering algorithm is applied to work out a problem that the tactual transaction-period is different from the graphic transaction- period. The graphic deformation algorithm is developed in the real-time using the deformed FEM. To apply the FEM, a deformed material-model is produced and then the graphic deformation with this model is able to force. Consequently, the graphic rendering algorithm is deduced by the real-time calculation and simplification because the purpose of this system is to transact in the real time. Applying this system to the PC, we prove that it is possible to deform the graphics and transact the haptic. Finally we suggest the variable simulation program to show the efficiency of this system.