• 대한산업공학회지
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• 제32권3호
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• pp.210-218
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• 2006

Traditional statistical process control (SPC) applied to discrete part industry in the form of control charts can look for and eliminate assignable causes by process monitoring. On the other hand, engineering process control (EPC) applied to the process industry in the form of feedback control can maintain the process output on the target by continual adjustment of input variable. This study presents controlling and monitoring rules adopted by variable sampling interval (VSI) to change sampling intervals in a predetermined fashion on the predicted process levels under integrated EPC and SPC systems. Twelve rules classified by EPC schemes(MMSE, constrained PI, bounded or deadband adjustment policy) and type of sampling interval combined with EWMA chart of SPC are proposed under IMA (1,1) disturbance model and zero-order (responsive) dynamic system. Properties of twelve control rules under three patterns of process change (sudden shift, drift and random shift) are evaluated and discussed through simulation and control rules for integrated VSI EPC and SPC systems are recommended.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2009년도 춘계 종합학술대회 논문집
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• pp.737-742
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• 2009

RIA 기술은 사용자의 경험을 강조하는 최근 트렌드에 힘입어 PC를 넘어, 핸드폰, TV 등 다양한 장치의 주요 사용자 인터페이스 및 소프트웨어 운용 플랫폼으로 자리 잡아가고 있다. 특히, RIA 기반 IPTV는 광고, 에듀테인먼트 등의 서비스에서 화려한 애니메이션 및 다양한 입력 장치에 기반한 첨단 상응식 콘텐츠의 개발을 가능하게 한다. 본 논문에서는 방송통신 융합형 감성 콘텐츠의 운용 및 서비스를 위한 프레임워크를 제안한다. IPTV용 플래시 콘텐츠 개발을 위한 확장프로그래밍 인터페이스를 제안하고 이를 지원하는 IPTV 미들웨어 및 플래시 런타임을 개발한다. 특히, 제안된 플래시 런타임은 하드웨어 그래픽 가속을 최대한 활용함으로써 저성능의 미디어 프로세서에서도 고감도 애니메이션을 지원하도록 설계되었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2237-2242
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• 2005

The original RRT is iteratively expanded by applying control inputs that drive the system slightly toward randomly-selected states, as opposed to requiring point-to-point convergence, as in the probabilistic roadmap approach. It is generally known that the performance of RRTs can be improved depending on the selection of the metrics in choosing the nearest vertex and bias techniques in choosing random states. We designed a path planning algorithm based on the RRT method for a remote-controlled mobile robot. First, we considered a bias technique that is goal-biased Gaussian random distribution along the command directions. Secondly, we selected the metric based on a weighted Euclidean distance of random states and a weighted distance from the goal region. It can save the effort to explore the unnecessary regions and help the mobile robot to find a feasible trajectory as fast as possible. Finally, the constraints of the actuator should be considered to apply the algorithm to physical mobile robots, so we select control inputs distributed with commanded inputs and constrained by the maximum rate of input change instead of random inputs. Simulation results demonstrate that the proposed algorithm is significantly more efficient for planning than a basic RRT planner. It reduces the computational time needed to find a feasible trajectory and can be practically implemented in a remote-controlled mobile robot.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 총회 및 춘계학술발표회
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• pp.3-6
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• 2001

Various Parameters such as stream velocities, discharges, and dispersion coefficients of dissolved solutes were estimated by fitting 1-D nonreactive solute transport model to the time-series chemistry data. This study was done for the reaches of Mankyung River lower than the Jeonju Wastewater Treatment Plant (Jeonju WTP). Korea. Concentrations of inorganic chemicals in the stream waters are strongly influenced by mixing with the chemically distinct effluent from Jeonju WTP. Sulfate, EC. and the total major cation were proved to be nearly conservative in the study area front their relationships with chloride, the conservative chemical species. The solute transport model was constrained to the time-series concentrations for these 4 conservative species. The variations of concentration and discharge of Jeonju WTP were used as input parameters, and the stream velocities, dispersion coefficients, and concentrations and discharges of some inflows were optimized. The differences between the observed arid simulated values for alkalinities and nitrates are inversely correlated and show diurnal fluctuations, indicating the photosynthesis. The parameters obtained front this mode] range from 550 to 774 kcmd (stream discharge at the outlet of the study area), from 0.06 to 0.10 m/sec (flow velocity), and from 0.7 to 6.4 m$^2$/sec (dispersion coefficient). The history of Jeonju WTP discharge was well predicted when optimized, indicating the validity of the model results.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.923-928
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• 2003

This paper presents the motion control of a mobile robot with arc sensor for lattice type welding. Its dynamic equation and motion control method for welding speed and seam tracking are described. The motion control is realized in the view of keeping constant welding speed and precise target line even though the robot is driven along a straight line or comer. The mobile robot is modeled based on Lagrange equation under nonholonomic constraints and the model is represented in state space form. The motion control of the mobile robot is separated into three driving motions of straight locomotion, turning locomotion and torch slider controls. For the torch slider control, the proportional integral derivative (PID) control method is used. For the straight locomotion, a concept of decoupling method between input and output is adopted and for the turning locomotion, the turning speed is controlled according to the angular velocity value at each point of the comer with range of $90^{\circ}$ constrained to the welding speed. The proposed control methods are proved through simulation results and the results have proved that the mobile robot has enough ability to apply the lattice type welding line.

• Journal of Mechanical Science and Technology
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• 제16권1호
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• pp.83-93
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• 2002

This paper presents a motion control method and its simulation results of a mobile robot for a lattice type welding. Its dynamic equation and motion control methods for welding speed and seam tracking are described. The motion control is realized in the view of keeping constant welding speed and precise target line even though the robot is driven for following straight line or curve. The mobile robot is modeled based on Lagrange equation under nonholonomic constraints and the model is represented in state space form. The motion control of the mobile robot is separated into three driving motions of straight locomotion, turning locomotion and torch slider control. For the torch slider control, the proportional-integral-derivative (PID) control method is used. For the straight locomotion, a concept of decoupling method between input and output is adopted and for the turning locomotion, the turning speed is controlled according to the angular velocity value at each point of the corner with range of 90$^{\circ}$ constrained to the welding speed. The proposed control methods are proved through simulation results and these results have proved that the mobile robot has enough ability to apply the lattice type welding line.

• 대한전자공학회논문지
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• 제25권10호
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• pp.1263-1273
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• 1988

LMS 기법을 이용한 적응 신호 처리상에서 복합적으로 제기 되어온 간섭신호 제거, 수렴속도, 오차조정 및 기준신호 발생 등의 전체적인 문제점들을 합성적으로 고려한 하나의 적응 기법이 제시된다. 제안된 방법은 최소화 적응 처리를 하기전에 먼저 어레이 입력으로 들어오는 복합신호로부터 표적신호를 분리하고, 기준신호를 제거한다. 본 기법은 적응처리기에 있는 잔유잡음의 정도에 제한을 둔다. 분석결과 본 기법은 코히어런트 또는 인코히어런트 간섭신호 제거에 효과적이며 특히, 수렴계수의 동적범위가 넓어 안정도가 좋고 수렴속도가 빠르며 평균자승오차가 매우적다. 또한, 기준신호발생이 필요없다는 장점이 있다. 시뮬레이션 결과는 이론적인 예측과 일치한다.

• 한국통신학회논문지
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• 제18권9호
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• pp.1358-1367
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• 1993

전적으로 수입에 의존하는 마크판독장치(OMR : Optical Mark Reader)와 문자판독장치(OCR : Optical Character Reader)는 Line scan 방식으로 급지장치가 복잡하며 용지에 제한을 받는 등의 단점을 갖는다. 본 논문에서는 새로운 방식인 CCD카메라와 디지타이져를 입력장치로 하여 영상처리와 패턴인식에 근거한 마크와 숫자를 동시에 실시간 인식 가능한 일명 OMCR(Optical Mark and Character Reader) 시스템을 연구, 개발하였다. 또한 착오에 의하여 마크를 잘못 기입함으로써 발생할 수 있는 문제점을 개선하기 위한 표기방법으로 마크 대신에 제한된 7-segment의 및 필기체 숫자형식을 본 논문에서 제안하였다. 대학의 입학원서, 입시답안지, 수강신청, 성적평가표 및 주소에 대한 수만장의 마크용지와 영수증에 포함된 40개 이내인 인쇄체 숫자부분에 대한 문자용지를 실험대상으로 하였다. 실험결과, 마크용지와 문자용지 모두 판독 에러없이 초당 3~4장의 실시간 판독이 가능하였으며 line scan 방식의 OMR이나 OCR이 갖는 단점을 해결하였음을 입증하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제4권2호
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• pp.117-137
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• 2010

Iris recognition is a biometric technique which uses unique iris patterns between the pupil and sclera. The advantage of iris recognition lies in high recognition accuracy; however, for good performance, it requires the diameter of the iris to be greater than 200 pixels in an input image. So, a conventional iris system uses a camera with a costly and bulky zoom lens. To overcome this problem, we propose a new method to restore a low resolution iris image into a high resolution image using a single image. This study has three novelties compared to previous works: (i) To obtain a high resolution iris image, we only use a single iris image. This can solve the problems of conventional restoration methods with multiple images, which need considerable processing time for image capturing and registration. (ii) By using bilinear interpolation and a constrained least squares (CLS) filter based on the degradation model, we obtain a high resolution iris image with high recognition performance at fast speed. (iii) We select the optimized parameters of the CLS filter and degradation model according to the zoom factor of the image in terms of recognition accuracy. Experimental results showed that the accuracy of iris recognition was enhanced using the proposed method.

• 한국지능시스템학회논문지
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• 제20권6호
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• pp.768-773
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• 2010

본 논문에서는 도립진자 시스템을 이용한 최적 상태 되먹임 제어기 설계 및 성능 검증을 소개한다. 제안하고 있는 최적 상태 되먹임 제어기는 최적제어 이론을 기반으로 입력크기와 응답성능의 최적값을 고려하였고 뿐만 아니라, 적분제어기법을 도입함으로써 정상상태오차를 줄이도록 하였다. 실험에 사용된 도립진자 시스템은 (주)셈웨어의 PC기반 CEM-IP-01으로써 제안된 제어기를 적용한다. 마지막으로 제안된 제어기와 일반 상태 되먹임 제어기를 모의실험과 실험을 통하여 비교함으로써 제안된 제어기의 성능을 검증한다.