• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2429-2432
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• 2000

Adaptive filter algorithm has been used for plant identifier and noise cancellation. This algorithm has been researched for performance enhancement of filtering. The design and development of a reliable system has been becoming a key issue in industry field because the reliability of a system is considered as an important factor to perform the system's function successfully. And the computing with reliability and fault tolerance is a important factor in the case of aviation and nuclear plant. This paper presents design of reliable adaptive filter with fault tolerance. Generally, redundancy is used for reliability. In this case it needs computing or circuit for voting mechanism or computing for fault detection or switching part. But this presented Filter is not in need of computing for voting mechanism, or fault detection. Therefore it has simple computing, and practicality for application. And in this paper, reliability of adaptive filter is analyzed. The effectiveness of the proposed adaptive filter is demonstrated to the case studies of plant identifier and noise cancellation by using DSP.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제6권6호
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• pp.635-642
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• 2000

본 논문에서는 이동 단말에 적응적으로 웹 문서를 제공할 수 있는 효율적인 문서 변환 방법과 적응적 태그 단순화(tag reduction)를 수행하기 위한 RHTML(Reduced HTML)을 제안하였다. 제안한 적응적 문서 변환 방법은 마크업(markup) 오류 제거 과정을 통해 HTML(HyperText Markup Language) 문서를 XML(Extensible Markup Language)의 응용 문서로 변환한다. 이를 통해 웹 문서는 DOM(Document Object Model)을 사용하여 트리 구조로 손쉽게 다루어질 수 있게 되며, 따라서 이동 단말에서 마크업 오류를 수정하는 하드웨어의 부하를 제거할 수 있다. 또한 제안한 문서를 단순화하는 과정에서는 RHTML에 정의 된 3가지의 DTD(Document Type Definition)중 하나를 참고하여 이동 단말에 적응적으로 웹문서를 제공한다.

• Nuclear Engineering and Technology
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• 제54권5호
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• pp.1644-1651
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• 2022

This paper focuses on the power-level control of nuclear power plants (NPPs) in the presence of lumped disturbances. An adaptive second-order nonsingular terminal sliding mode control (ASONTSMC) scheme is proposed by resorting to the second-order nonsingular terminal sliding mode. The pre-existing mathematical model of the nuclear reactor system is firstly described based on point-reactor kinetics equations with six delayed neutron groups. Then, a second-order sliding mode control approach is proposed by integrating a proportional-derivative sliding mode (PDSM) manifold with a nonsingular terminal sliding mode (NTSM) manifold. An adaptive mechanism is designed to estimate the unknown upper bound of a lumped uncertain term that is composed of lumped disturbances and system states real-timely. The estimated values are then added to the controller, resulting in the control system capable of compensating the adverse effects of the lumped disturbances efficiently. Since the sign function is contained in the first time derivative of the real control law, the continuous input signal is obtained after integration so that the chattering effects of the conventional sliding mode control are suppressed. The robust stability of the overall control system is demonstrated through Lyapunov stability theory. Finally, the proposed control scheme is validated through simulations and comparisons with a proportional-integral-derivative (PID) controller, a super twisting sliding mode controller (STSMC), and a disturbance observer-based adaptive sliding mode controller (DO-ASMC).

• 한국인터넷방송통신학회논문지
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• 제16권6호
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• pp.141-146
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• 2016

굴착 현장 인접 구조물의 안정성을 확보하기 위해 현장 주변 지반의 변형을 모니터링하는 것은 중요하다. 지반특성과 굴착 깊이에 따라 굴착 중 벽체의 변형이 다르게 발생하며, 이를 정확하게 예측하는 것은 불가능하다. 따라서 굴착지지 벽체 후방에 인클리노미터를 탑재한 센서를 설치하여 이를 모니터링한다. 본 논문에서는 굴착과정에서 벽체의 변형을 모니터링하기 위해 무선 센서 노드를 사용한 모니터링 시스템을 설계하였다. 또한 배터리 기반의 센서 노드의 수명을 연장하기 위해 굴착 진행 과정과 인클리노미터의 계측 값에 따라 위험도 등급을 설정하고 해당 등급에 따라 활성/휴면 구간을 적응적으로 변경하는 기법을 제안하였다. 지연시간 분석을 통해 제안기법은 굴착현장과 같이 위험도가 다른 데이터가 동적으로 발생하는 환경에서 고정 듀티사이클링 기법에 비해 지연시간을 크게 줄일 수 있음을 확인한다.

• 인터넷정보학회논문지
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• 제4권2호
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• pp.39-45
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• 2003

네트워크에서 QoS를 지원하기 위한 적응제어 구조를 개발하기 위해서는 대역폭 할당에 따른 전송율 응답특성을 모델링하는 것이 필수적이다. 본 연구에서는 네트워크의 대역폭 할당에 따른 전송율의 동적 특성을 구현하는 "동적 시스템 모델"을 제안하고 적응 피드백 제어 구조를 제안된 모델에 적용시켜 시뮬레이션 및 모델의 최적화를 수행하였다.적화를 수행하였다.

• ETRI Journal
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• 제40권4호
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• pp.483-498
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• 2018

Nowadays, with progresses in robotic science, the design and implementation of a mechanism for human-robot interaction with a low workload is inevitable. One notable challenge in this field is the interaction between a single human and a group of robots. Therefore, we propose a new comprehensive framework for single-human multiple-robot remote interaction that can form an efficient intelligent adaptive interaction (IAI). Our interaction system can thoroughly adapt itself to changes in interaction context and user states. Some advantages of our devised IAI framework are lower workload, higher level of situation awareness, and efficient interaction. In this paper, we introduce a new IAI architecture as our comprehensive mechanism. In order to practically examine the architecture, we implemented our proposed IAI to control a group of unmanned aerial vehicles (UAVs) under different scenarios. The results show that our devised IAI framework can effectively reduce human workload and the level of situation awareness, and concurrently foster the mission completion percentage of the UAVs.

• 한국멀티미디어학회논문지
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• 제19권12호
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• pp.1992-1999
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• 2016

In layered communication architecture, each layer is designed to service its own functions to higher layer while getting serviced by lower layer. Usually layered architectures are not optimized in a total view of whole services and functions. So cross layer design pursues performance enhancements by optimizing in various ways. In LTE, MAC layer uses HARQ mechanism and RLC layer uses ARQ mechanism for retransmission. According to the 3GPP 36.331 specification, two layers' cooperation may not happen in an optimized way. This paper suggests an adaptive MAC layer approach which RLC layer's function might be initiated in MAC layer in advance to utilize MAC layer's idling wasting time for RLC layer's next decision. This adaptive ARQ method in MAC layer speeds up the next retransmission and reduces the overall transmission time. Emulation shows the improved performance in total retransmission time and retransmission success ratio. In wireless shadow area, the retransmission occurs frequently. Our approach has strong points in this poor wireless condition.

• Journal of Mechanical Science and Technology
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• 제16권3호
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• pp.310-319
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• 2002

This paper deals with the analytical modeling, and the experimental verification of the strain rate self-sensing method using a hybrid adaptive filter for a cantilevered piezoelectric beam. The piezoelectric beam consists of two laminated lead zirconium titanates (PZT) on a metal shim. A mathematical model of the beam dynamics is derived by Hamilton's principle and the accuracy of the modeling is verified through the comparison with experimental results. For the strain rate estimation of the cantilevered piezoelectric beam, a self-sensing mechanism using a hybrid adaptive filter is considered. The discrete parts of this mechanism are realized by the DS1103 DSP board manufactured by dSPACE$\^$TM/. The efficacy of this method is investigated through the comparison of experimental results with the predictions from the derived analytical model.

• 전기학회논문지P
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• 제61권4호
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• pp.161-167
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• 2012

Energy conversion systems such as power inverters and converters are basically significant in establishing photovoltaic power systems to enhance power effectiveness. This paper proposes a new converter control method by using the Lyapunov redesign approach. We construct the proposed control mechanism linearly composed of nominal control and auxiliary control laws. The former is generally designed through a well-known power electronic technology and the latter is implemented to compensate real-time control error due to uncertain natures of converter systems in practice. For realizing adaptive control capability in the proposed control mechanism, a control parameter vector is estimated by utilizing a steepest descent based optimization method. We carry out numerical simulation with Matlab(c) software to demonstrate reliability of the proposed converter control system and conduct a comparative study to prove its superiority by comparing with a generic converter control methodology.

• 한국통신학회논문지
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• 제32권4B호
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• pp.208-216
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• 2007

Wireless Sensor Networks (WSNs) are characterized by low capacity on each nodes and links. Wireless links have high bit error rate (BER) parameter that changes frequently due to the changes on network topology, interference, etc. To guarantee reliability in an error-prone environment, a retransmission mechanism can be used. In this mechanism, the number of retransmissions is used as a parameter that controls reliability requirement level. In this paper, we propose an Error Adaptive Transport Protocol (EATP) for WSNs that updates the number of retransmissions regularly to guarantee reliability during bit error rate changes as well as to utilize energy effectively. The said algorithm uses local information, thus, it does not create overhead problem.