• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.487-489
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• 1997

The control of the switched reluctance motor is usually on the inductance profiles as a function of position. In this paper, a control scheme to maximize the motor torque is proposed by determining optimal turn-off angle with a self-tuning control method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1380-1385
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• 2004

In this paper, auto-tuning technique of the PID controller gain by particle swarm optimization algorithm is presented. PID controller is easy to implement to numerous control systems. After PID gain tuning is completed, its result could be implemented to control spacecraft vibration such as jitter that is high frequency vibration usually over 10Hz. The off-line PID controller tuning is done under system nonlinearities and uncertainties existence, then its result is applied to control experiment device to prove the PSO efficiencies.

• Journal of the Korean Data and Information Science Society
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• 제26권3호
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• pp.549-559
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• 2015

MDPDE는 이상치에 강건한 성질을 가진 추정량으로써 최대우도추정량의 대안으로 많은 연구자들에 의해 연구되어 왔다. MDPDE는 조율모수에 따라 성질이 변하게 되는데, 로버스트성과 점근효율성이 서로 상충하는 현상으로 인해 최적의 조율모수를 선택하는 것은 쉽지 않다. 본 연구에서는 MDPDE의 최적의 조율모수를 선택하는 방법으로 Fujisawa와 Eguchi (2006)가 제시한 방법과 Warwick (2006)이 제시한 방법을 소개하고, 모의실험을 통해 비교분석하였다. 연구 결과 Warwick (2006)의 방법은 특정한 경우 매우 작은 조율모수를 선택하게 될 수도 있다는 사실을 알 수 있었는데, 같은 경우에 Fujisawa와 Eguchi (2006)의 방법은 이러한 현상을 보이지 않았다. 따라서, Fujisawa와 Eguchi (2006)의 방법이 범용적으로 사용하기에 적절하다고 판단된다.

• 말소리와 음성과학
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• 제15권3호
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• pp.83-88
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• 2023

This study investigates the fine-tuning of large-scale Automatic Speech Recognition (ASR) models, specifically OpenAI's Whisper model, for domain-specific applications using the KsponSpeech dataset. The primary research questions address the effectiveness of targeted lexical item emphasis during fine-tuning, its impact on domain-specific performance, and whether the fine-tuned model can maintain generalization capabilities across different languages and environments. Experiments were conducted using two fine-tuning datasets: Set A, a small subset emphasizing specific lexical items, and Set B, consisting of the entire KsponSpeech dataset. Results showed that fine-tuning with targeted lexical items increased recognition accuracy and improved domain-specific performance, with generalization capabilities maintained when fine-tuned with a smaller dataset. For noisier environments, a trade-off between specificity and generalization capabilities was observed. This study highlights the potential of fine-tuning using minimal domain-specific data to achieve satisfactory results, emphasizing the importance of balancing specialization and generalization for ASR models. Future research could explore different fine-tuning strategies and novel technologies such as prompting to further enhance large-scale ASR models' domain-specific performance.

• 한국공간구조학회논문집
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• 제6권3호
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• pp.59-67
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• 2006

수동동조질량감쇠기의 진동제어 효과는 질량감쇠기와 구조물과의 동조로 인하여 나타나고 있다. 그러나 바닥판 구조물의 질량과 강성의 변화로 인하여 실제 구조물에 있어서 비동조 현상이 일어나기도 한다. 이러한 상황에서는 수동동조질량감쇠기의 성능이 비효율적이며 경우에 따라서는 구조물의 진동을 증가시키기도 한다. 본 논문에서는 기계나 사람에 의한 바닥판 구조물의 진동을 줄이기 위하여 자기유체감쇠기의 적용성을 알아보고자 한다. 준 능동제어와 groundhook 제어 알고리즘을 적용하여 준능동감쇠기의 성능과 수동질량감쇠기의 성능을 비교 분석하였다. 또한 비동조 상황에서의 준능동감쇠가와 수동질량감쇠기의 견인성을 비교 분석하여 다음과 같은 결론을 얻었다. 자기유체감쇠기는 동조상황에서 우수한 제어 성능을 가지고 있으며 비동조 상황에서도 우수한 견인성을 보여주고 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.279-281
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• 2006

In this paper, we study an approach to design a self-tuning Fuzzy-PI controller in HVDC(High Voltage Direct Current) system. In the rectifier of conversional HVDC system, turning on, turning off, triggering and protections of thyristors have lots of problems that can make the dynamic instability and cannot damp the dynamic disturbance efficiently. The above problems are solved by adapting Fuzzy-PI controller for the fire angle control of rectifier.[7] The performance of the Fuzzy-PI controller is sensitive to the variety of scaling factors. The design procedure dwells on the use of evolutionary computing(Genetic Algorithms, GAs). Then we can obtain the optimal scaling factors of the Fuzzy-PI controller by Genetic Algorithms. In order to improve Fuzzy-PI controller, we adopt FIS to tune the scaling factors of the Fuzzy-PI controller on line. A comparative study has been performed between Fuzzy-PI and self-tuning Fuzzy-PI controller, to prove the superiority of the proposed scheme.

• 한국지능시스템학회논문지
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• 제12권3호
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• pp.246-254
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• 2002

In this paper auto-tuning scheme of PID controller based on the reference model has been studied for a Process control system by immune algorithm. Up to this time, many sophisticated tuning algorithms have been tried in order to improve the PID controller performance under such difficult conditions. Also, a number of approaches have been proposed to implement mixed control structures that combine a PID controller with fuzzy logic. However, in the actual plant, they are manually tuned through a trial and error procedure, and the derivative action is switched off. Therefore, it is difficult to tune. Since the immune system possesses a self organizing and distributed memory, it is thus adaptive to its external environment and allows a PDP (Parallel Distributed Processing) network to complete patterns against the environmental situation. Simulation results reveal that reference model basd tuning by immune network suggested in this paper is an effective approach to search for optimal or near optimal process control.

• 대한전기학회논문지:전력기술부문A
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• 제51권2호
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• pp.69-75
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• 2002

AVR parameter tuning for voltage control of power system generators has generally been performed with the analytic methods and the simulation methods, which mostly depend on off-line linear mathematical models of excitation control system. However, due to the nonlinear nature of excitation control system, excitation control system performance of the tuned Parameters using the above conventional tuning methods may not be appropriate for some operating conditions. This paper presents an AVR parameter tuning method using actual on-line data of the excitation control system with the parameter optimization technique. As this method utilizes on-line operating data of the target excitation control system not the mathematical model of the system, it can overcome the limitation of model uncertainty Problems in conventional method, and it can tune the AVR parameter set which gives desired performance at the operating conditions. For the verification of proposed tuning method, two case studies with scaled excitation systems and the real-time power system simulator are presented.

• 한국정보처리학회논문지
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• 제6권9호
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• pp.2332-2342
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• 1999

멀티캐스트는 중요한 시스템 레벨의 그룹 프로세스들을 수반하는 통신 서비스의 한 클래스이다. 소프트웨어 멀티캐스트 알고리즘을 설계하는데 있어서의 주된 문제는 성능과 이식성 사이의 교환조건(trade-off)을 고려하는 것이다. 본 논문에서 제안하는 변수화 된 통신 모델은 LogP 모델의 확장으로 병렬 플랫폼의 통신 네트워크를 더 정확하게 특성화 할 수 있다. 이 변수화 된 모델에서, 컴퓨터 구조에 의존적이지 않고 이식성 있는 OPT-tree라는 최적의 멀티캐스트를 형성하는 알고리즘을 제안한다. 실제 여러 네트워크에 구현했을 때 진정한 최적의 수행을 달성하기 위해서 OPT-tree로 생성된 트리에서의 네트워크 위상에 따른 튜닝(tuning)에 대해 연구한다. 특히 웜홀 스위치를 사용하는 메쉬(mesh) 네트워크에서 변수화 된 멀티캐스트 알고리즘의 최적화 한 버전인 OPT-mesh 알고리즘을 개발하여 다른 알고리즘들과 비교하여 그 우수성을 검증한다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2007년도 정기 학술대회 논문집
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• pp.607-612
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• 2007

A conventional passive TMD is only effective when it is tuned properly. In many practical applications, inevitable off-tuning of a TMD occurs because the mass in a building floor could change by moving furnishings, people gathering, etc. When TMDs are off tuned, TMDs their effectiveness is sharply reduced. This paper discusses the application of MR-TMD, semi-active damper, for the reduction of floor vibrations due to machine and human movements. Here, the groundhook and skyhook algorithm are applied to a single degree of freedom system representative of building floors. And displacement and velocity base control method are applied to reduce t100r vibration. The performance of the STMD is compared to that of the equivalent passive TMD. Comparison of the results demonstrates the efficiency and robustness of STMD with respect to equivalent TMD.