• Journal of Mechanical Science and Technology
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• 제14권4호
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• pp.369-379
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• 2000

In industrial production-distribution systems, production and purchasing rates, associated inventories, and sales are very critical for the profits of each component in the system. The objective of this study is to investigate an effective information control scheme for a production -distribution system by automatic feedback control techniques. In this work, a dynamic control scheme that has an integrated -error with state-feedback and filtering (ISFF) is proposed as a new algorithm for a dynamic controller. Generalized formulations of the dynamic control are proposed in the continuous-time and discrete-time cases. A methodology for an evaluation of ISFF controller gains using the eigen structure property is presented. When an upper-limit is imposed on the production capability by available factory space and capital equipment, supervisory control is provided to avoid integrator-windup and deterioration of system performance.

• 정보처리학회논문지C
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• 제9C권6호
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• pp.953-960
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• 2002

실시간 응용 프로그램은 미디어 데이터간에 만족되어야 할 동기화 제약조건(synchronization constraints)을 가지고 있다. 멀티미디어 데이터의 가변적 전송 시연 시간을 흡수하여 피드백 제어와 재생정책에 의한 동기화 기법을 수행한다. 버퍼의 수위가 정상레벨을 유지하는가에 대한 문제는 재생률과 QoS 서비스에 중요한 영향을 주게 된다. 본 논문에서는 버퍼의 수위를 안정상태고 유지하기 위해 피트백을 위한 필터링함수를 적용하고, 재생시간을 적응적으로 적용하여 미디어의 재생 시 끊어짐이 없는 유연한 재생을 한다. 또한 버퍼의 주 미디어인 오디오 프레임의 버퍼가 상위임계레벨에 수위가 존재 할 경우는 적응적으로 재생시간을 줄이고, 하위임계레벨에 버퍼의 수위가 있을 경우는 점차적으로 재생시간을 늘리는 시스템이다.

• Journal of information and communication convergence engineering
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• 제18권2호
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• pp.123-131
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• 2020

After observing that most tourists plan to complete their visits to multiple cultural heritage sites within one day, we surmised that for many museum visitors, the foremost thought is with regard to the amount of time is to be spent at each location and how they can maximize their enjoyment at a site while still balancing their travel itinerary? Recommendation systems in e-commerce are built on knowledge about the users' previous purchasing history; recommendation systems for museums, on the other hand, do not have an equivalent data source available. Recent solutions have incorporated advanced technologies such as algorithms that rely on social filtering, which builds recommendations from the nearest identified similar user. Our paper proposes a different approach, and involves providing dynamic recommendations that deploy social filtering as well as content-based filtering using term frequency-inverse document frequency. The main challenge is to overcome a cold start, whereby no information is available on new users entering the system, and thus there is no strong background information for generating the recommendation. In these cases, our solution deploys statistical methods to create a recommendation, which can then be used to gather data for future iterations. We are currently running a pilot test at Chao Samphraya national museum and have received positive feedback to date on the implementation.

• 한국전자파학회논문지
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• 제18권2호
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• pp.177-182
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• 2007

본 논문은 InGaP/GaAs HBT 공정을 통해 제작한 적응성궤환 잡음제거시스템용 낮은 위상잡음을 갖는 LC 차동 전압제어 발진기를 제안합니다. 전압제어 발진기는 필터링 기술을 포함한 향상된 공진 탱크 구조를 갖습니다. 비대칭 인덕터 대칭 캐패시터 구조로 제안된 전압제어 발진기의 출력 가변 범위는 207 MHz입니다. 출력 전력은 balun과 케이블 손실을 포함하여 -6.68 dBm입니다. 10 kHz, 100 kHz, 1 MHz에서의 위상잡음은 각각 -102.02, -112.04 그리고 -130.4 dBc/Hz입니다. 이 전압제어 발진기는 총 $0.9{\times}0.9mm^2$ 면적 내에 집적화되었습니다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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• pp.107-110
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• 1996

Continuing advances in the formulation and solution of risk-sensitive control problems have reached a point at which this topic is becoming one of the more intriguing modern paradigms of feedback thought. Despite a prevailing atmosphere of close scrutiny of theoretical studies, the risk-sensitive body of knowledge is growing. Moreover, from the point of view of applications, the detailed properties of risk-sensitive design are only now beginning to be worked out. Accordingly, the time seems to be right for a survey of the historical underpinnings of the subject. This paper addresses the beginnings and the evolution, over the first quarter-century or so, and points out the close relationship of the topic with the notion of optimal cost cumulates, in particular the cost variance. It is to be expected that, in due course, some duality will appear between these notions and those in estimation and filtering. The purpose of this document is to help to lay a framework for that eventuality.

• 제어로봇시스템학회논문지
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• 제9권11호
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• pp.917-924
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• 2003

Recurrent neural networks have been successfully applied to communications channel equalization. Major disadvantages of gradient-based learning algorithms commonly employed to train recurrent neural networks are slow convergence rates and long training sequences required for satisfactory performance. In a high-speed communications system, fast convergence speed and short training symbols are essential. We propose decision feedback equalizers using a recurrent neural network trained with Kalman filtering algorithms. The main features of the proposed recurrent neural equalizers, utilizing extended Kalman filter (EKF) and unscented Kalman filter (UKF), are fast convergence rates and good performance using relatively short training symbols. Experimental results for two time-varying channels are presented to evaluate the performance of the proposed approaches over a conventional recurrent neural equalizer.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.592-597
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• 2003

In this paper, some differential geometric conditions for the observer using a recurrent neural network are provided in terms of a stochastic nonlinear system control. In the stochastic nonlinear system, it is necessary to make an additional condition for observation of stochastic nonlinear system, called perfect filtering condition. In addition, we provide a observer using a recurrent neural network for the observation of a stochastic nonlinear system with the proposed observation conditions. Computer simulation shows that the control performance of the stochastic nonlinear system with a observer using a recurrent neural network satisfying the proposed conditions is more efficient than the conventional observer as Kalman filter

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1406-1409
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• 2004

The Resolver usually used in industry is the absolute angle analog sensor that must be in order to driving BLDC (brushless DC) motor, and it needs RDC(Resolver-to-Digital converter) for changing the output signal to digital to be applied to the SVPWM(Space Vector Pulse Width Modulation) algorithm. Commonly used S/W RDC needs trigonometric function. What it takes a lot of calculation time of processor is gotten at weak point. In this paper, S/W RDC is realized except trigonometric functions as a result of feedback resolver outputs after filtering using FIR filter. thus, processing time is reduced. So, One-chip DSP Controller operating the Vector Control, RDC, and SVPWM can be designed.

• 한국통신학회논문지
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• 제21권8호
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• pp.1885-1896
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• 1996

This paper describes the implementation of the AVT(Automatic video Tracker) using ASIC. The basic tracking algorithm is based on the spatio-temporal gradient method, and adaptive window sizing, track state decision algorithm were also realized. Newly developed ASIC performs recursive image filtering, extraction of spatio-temporal gradient/gradient functions of image in field rate. Using the FPGA/ASIC, the tracker was simply realized in one board type which can be easily applied to various image system. We conformed ASIC operation by computer simulation and tested the system in real tracking situations. From the result, the system can track the moving target which has a velocity of 2-3 pixel/field and a size of varying from 2 to 128 pixes. Also fast refresh rateof motion estimation(60Hz) improves the characteristics of servoing system which forms feedback loop with the tracker.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 하계학술대회 논문집
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• pp.47-50
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• 1990

Deafs cannot speak straight voice as normal people in lack of feedback of their pronunciation, therefore speech training is required. In this study, fundamental frequency, intensity, formant frequencies, vocal tract graphic and vocal tract area function, extracted from speech signal, are used as feature parameter. AR model, whose coefficients are extracted using inverse filtering. is used as speech generation model. In connect ion between vocal tract graphic and speech parameter, articulation distances and articulation distance functions in selected 15-intervals are determined by extracted vocal tract areas and formant frequencies.