• 제어로봇시스템학회논문지
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• 제8권10호
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• pp.827-832
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• 2002

We propose a prediction method of the pollutant and a synchronous classification of the current state of SOx emission in the power plant. We use the auto-regressive with exogeneous (ARX) model as a predictor of SOx emission and use a radial basis function network (RBFN) as a pattem classifier. The ARX modeling scheme is implemented using recursive least squares (RLS) method to update the model parameters adaptively. The capability of SOx emission monitoring is utilized with the application of the RBFN classifier. Experimental results show that the ARX model can predict the SOx emission concentration well and ARX modeling parameters can be a good feature for the state monitoring. in addition, its validity has been verified through the power spectrum analysis. Consequently, the RBFN classifier in combination with ARX model is shown to be quite adequate for monitoring the state of SOx emission.

• International journal of advanced smart convergence
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• 제1권2호
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• pp.1-11
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• 2012

IP-based Wireless Sensor Networks (IP-WSNs) are gaining importance for their broad range of applications in health care, home automation, environmental monitoring, industrial control, vehicle telematics, and agricultural monitoring. In all these applications, a fundamental issue is the mobility in the sensor network, particularly with regards to energy efficiency. Because of the energy inefficiency of network-based mobility management protocols, they can be supported via IP-WSNs. In this paper, we propose a network-based mobility-supported IP-WSN protocol called mSFP, or the mSFP: "Multicasting-supported Inter-Domain Mobility Management Scheme in Sensor-based Fast Proxy Mobile IPv6 Networks". Based on [8,20], we present its network architecture and evaluate its performance by considering the signaling and mobility cost. Our analysis shows that the proposed scheme reduces the signaling cost, total cost, and mobility cost. With respect to the number of IP-WSN nodes, the proposed scheme reduces the signaling cost by 7% and the total cost by 3%. With respect to the number of hops, the proposed scheme reduces the signaling cost by 6.9%, the total cost by 2.5%, and the mobility cost by 1.5%. With respect to the number of IP-WSN nodes, the proposed scheme reduces the mobility cost by 1.6%.

• Journal of information and communication convergence engineering
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• 제6권2호
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• pp.129-133
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• 2008

In this paper, modified power control algorithms are proposed for a satellite mobile communications system with ATC (ancillary terrestrial component). In order to increase system capacity and reduce the transmitting power of the user's equipment, we propose the modified power control scheme consisting of the modified closed-loop and open-loop power control. The modified CLPC (closed-loop power control) algorithm, combining the delay compensation algorithms and pilot diversity, is mainly applied to the ATC link in urban areas because it is more suitable to the short RTD (round-trip delay). In the case of rural areas where ATCs are not deployed or a signal is not received from ATCs, combining monitoring transmitting power equipment and OLPC (open-loop power control) algorithms using an efficient pilot diversity is mainly applied to the link between the user's equipment and the satellite. Two power control algorithms are applied equally to the boundary areas where two kinds of signals are received in order to ensure coverage continuity. The simulation results show that the modified power control scheme has good performance compared to conventional power control schemes in a GEO (geostationary earth orbit) satellite system with ATC.

• 전자공학회논문지SC
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• 제49권2호
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• pp.1-9
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• 2012

본 논문에서는 이원화된 필드버스 기반의 선박 엔진용 분산 제어시스템을 설계 및 구현한다. 구현된 시스템은 엔진의 상태 값을 감시하기 위해서 CAN과 MODBUS 프로토콜을 혼합 형태로 이용하여 서로 다른 영역의 통신 구조로 구성한다. 첫 번째 층은 CAN프로토콜을 이용하여 엔진의 상태 값을 공유하게 된다. 두 번째 층은 MODBUS를 이용하여 엔진룸에서 기관실의 AMS로 모니터링 데이터 전송을 위한 통신을 지원한다. 테스트 베드 환경을 구축하여 구현된 시스템을 선급기술규칙의 요구사항에 의거하여 테스트 및 성능 검증하였다.

• 제어로봇시스템학회논문지
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• 제22권8호
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• pp.665-670
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• 2016

This paper proposes a repeat-back jamming signal detection scheme using a correlation ratio test metric of a combined pseudo-random noise signal for global navigation satellite systems. The correlation ratio test metric allows for the monitoring of possible distortions in the signal correlation. The proposed scheme is a modified version of the correlation ratio test metric to detect a repeat-back jamming signal in a multipath environment. Through a Monte-Carlo simulation, it is confirmed that the proposed scheme detects almost the whole case, which is received a repeat-back jamming signal under the 6 dB jamming to signal power ratio.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 1999년도 추계학술대회
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• pp.217-236
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• 1999

Engineering process control (EPC) is one of the techniques very widely used in process. EPC is based on control theory which aims at keeping the process on target. Statistical process control (SPC), also known as statistical process monitoring. The main purpose of SPC is to look for assignable causes (variability) in the process data. The combined SPC/EPC scheme is gaining recognition in the process industries where the process frequently experiences a drifting mean. This paper aims to study the difference between SPC and EPC in simple terms and presents a case study that demonstrates successful integration of SPC and EPC for a product in drifting industry. Statistical process control (SPC) monitoring of the special causes of a process, along with engineering feedback control such as proportional-integral-derivative (PID) control, is a major tool for on-line quality improvement.

• 한국인터넷방송통신학회논문지
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• 제16권4호
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• pp.97-108
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• 2016

본 논문에서는 넓은 개활지역에서의 신속한 재난 감시 및 탐지를 위하여 대규모 공중무인기로 구성된 협업 감시 네트워크를 고려한다. 관제센터의 한정된 자원은 다수의 공중무인기의 개별 제어에 제한이 있으며 이는 감시네트워크의 성능 저하를 가져온다. 따라서 공중무인기 기반 감시네트워크는 자율적 이동센서네트워크 구축, 재난지역 감시 범위 최대화, 재난발생 특성에 따른 효과적인 대형 변화 방안이 요구된다. 본 논문에서는 가상력을 이용한 대규모 공중무인기의 네트워크 구축 및 효율적 제어 알고리즘을 제안한다. 공중무인기의 회전 움직임을 바탕으로 감시범위의 확장과 네트워크의 분할과 합병을 통해 재난 지역의 효과적인 감시가 가능하다. 시뮬레이션을 이용하여 대규모 공중무인기 기반 협업 감시네트워크는 공중무인기 간 자율적 감시네트워크 구축, 네트워크의 신속한 지역 이동 그리고 넓은 지역의 효율적 감시가 가능하고 높은 이벤트 탐지율(Event Detection Ratio) 획득이 가능함을 보인다.

• Smart Structures and Systems
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• 제31권3호
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• pp.247-257
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• 2023

In structural health monitoring of large-scale structures, optimal sensor placement plays an important role because of the high cost of sensors and their supporting instruments, as well as the burden of data transmission and storage. In this study, a vibration sensor placement algorithm based on deep reinforcement learning (DRL) is proposed, which can effectively solve non-convex, high-dimensional, and discrete combinatorial sensor placement optimization problems. An objective function is constructed to estimate the quality of a specific vibration sensor placement scheme according to the modal assurance criterion (MAC). Using this objective function, a DRL-based algorithm is presented to determine the optimal vibration sensor placement scheme. Subsequently, we transform the sensor optimal placement process into a Markov decision process and employ a DRL-based optimization algorithm to maximize the objective function for optimal sensor placement. To illustrate the applicability of the proposed method, two examples are presented: a 10-story braced frame and a sea-crossing bridge model. A comparison study is also performed with a genetic algorithm and particle swarm algorithm. The proposed DRL-based algorithm can effectively solve the discrete combinatorial optimization problem for vibration sensor placements and can produce superior performance compared with the other two existing methods.

• 한국정밀공학회지
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• 제12권4호
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• pp.111-118
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• 1995

This paper presents the modified fuzzy-compensated PID(FCPID) control, which involves adding the compensator to an existing PID controller, to improve the performances of the systems. Compared to a conventional PID control and a fuzzy logic control(FLC), the proposed control scheme has superior performance. Experimental results of an actual implementation of the modified PC-based FCPID controller on the DC servo-motor demonstrate considerable improve- ment of the performance of the existing FCPID control by monitoring the scaling factor. They show faster responses and smaller overshoots than the conventional FCPID control scheme for the various reference inputs and the robustness to the loads.

• 한국통신학회논문지
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• 제31권10B호
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• pp.936-944
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• 2006

인터넷통신 서비스업체는, 최상위 기업경영 성과지표중 하나인 고객만족지수 향상을 위해, 전사적 품질경영을 전개하고 있다. 이와 관련, 고객만족지수와 연관성이 강한 기업내부 주요 인터넷통신 네트워크 품질특성에 대한 관리의 필요성이 제기되고 있다. 본 연구는, 인터넷통신 네트워크 품질특성 모니터 링을 위한 I-MR 관리도 활용체계를 제안한다. 네트워크 품질특성이 관리상태인지 모니터링하고, 네트워크 품질특성이 이상변동을 보이면, 이상원인 조사시점을 결정할 목적으로, 일정간격 연속 측정시점별; 1) 개별측정값 (individual measurements): 및 2) 연속 2개 개별측정값간 이동범위 (moving ranges)를 이용한 통계적 품질관리 체계인 I-MR 관리도를 활용한다. 사례분석에서는, 이상변동 발생시점에서 이상원인이 완전히 제거된다는 가정에 근거하여, 네트워크 품질특성의 실현가능한 치대 기대품질개선율이 계산된다. 인터넷통신 2개 Service A. B. Service별 7개 네트워크 품질특성 대상, 11개 측정지역의 기대품질개선율 평균, 표준편차를 분석, 1-MR 관리도 활용체계의 효과를 검토한다. 사례분석 결과, 기대품질개선율 범위는 다음과 같다. 1) Service A, (1) 평균 (0.31%-11.44%), (2) 표준편차 (9.82%-71.10%); 2) Service B, (1) 평균 (0.29%-17.64%), (2)표준편차 (8.05%-60.59%). 그러므로, 본 연구에서 설계·제안된 I-MR 관리도 활용체계는, 네트워크 품질특성의 평균 산포 개선 및 관리상태 유지에 효과적일 것으로 판단된다.