• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 추계학술대회 논문집
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• pp.301-305
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• 2001

Conventionally, robot control algorithms are divided into two stages, namely, path or trajectory planning and path tracking(or path control). This division has been adopted mainly as a means of alleviating difficulties in dealing with complex, complex, coupled manipulator dynamics. The minimum-time manipulator control problem is solved for the case when the path is specified and the actuator torque limitations are known. In path planning, DP is applied to applied to find the shortest path form initial position to final position with the assumptions that there is no obstacle and that each path is straight line. In path control, the phase plane technique is applied to the minimum-time control with the assumptions that the bound on each actuator torque is a function of joint position and velocity or constant. This algorithm can be used for any manipulator that has rigid link, known dynamics equations of motion, and joint angles that can be determined at a given position on the path.

• 전기학회논문지
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• 제59권1호
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• pp.76-81
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• 2010

This paper describes the development of integrated simulator with GUI(Graphic User Interface) for traction power supply system. This simulator consists of a lot of calculation modules such as TPS, train time schedule, line constant, and power supply system analysis. Each module has input and output structure respectively. The algorithms of all modules have confirmed the validity to comparison with field test that is performed on both high speed railway line and conventional line.

• 센서학회지
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• 제7권6호
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• pp.394-400
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• 1998

In this paper, we present a robust and fast method that enables real-time computing of axial motion component of different points of a scene from a stereo images sequence. The aim of our method is to establish axial motion maps by computing a range of disparity maps. We propose a solution in two steps. In the first step we estimate motion with a low level computing for an image point by a detection estimation-structure. In the second step, we use the neighbourhood information of the image point with morphology operation. The motion maps are established with a constant computation time without spatio-temporal matching.

• 한국정보처리학회논문지
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• 제6권1호
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• pp.66-74
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• 1999

사진트리를 메모리에 저장하는 방법 중 선형 사진트리 표현 방법은 다른 표현 방법과 비교할 때 저장 공간을 매우 효율적으로 절약할 수 있는 장점을 가진다. 따라서 지금가지 사진트리와 관련된 연산의 수행에 있어, 선형 사진트리를 사용하는 효율적인 알고리즘들이 많이 개발되고 연구되어 왔다. 본 논문에서는 RMESH(Reconfigurable MESH) 구조에서 3-차원 n$\times$n$\times$n 프로세서를 사용하여 선형 사진트리로 표현된 이진 영상의 이웃 블록들을 찾는 알고리즘을 제안한다. 이 알고리즘은 O(1)시간 복잡도를 잡는다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1237-1240
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• 1996

This paper proposes a heuristic algorithm for performing the line balancing of PCB assembly fine including multiple surface mounters efficiently. We consider a PCB assembly line including the multiple surface mounters arranged serially as a target system. We assume that the number of heads of surface mounters can be changed. Also, the conveyor is assumed to move at a constant speed and have no buffer. Considering the minimum number of machines required for the desired production rate is a discrete nonincreasing function which is inversely proportional to the cycle time, we propose an optimization algorithm for line balancing by using the binary search method. Also we propose an head-changing algorithm. The algorithms are validated through the computer simulation.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.371-374
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• 1997

This study presents a new type of real-t~me CNC interpolator that is capable of generating cutter paths for ball-end milling of NURBS surfaces. The proposed surface interpolator comprises real-time algorithms for cutter-contact (CC) path scheduling and CC path interpolation. Especially, in this study, a new interpolator module to regulate cutting forces is developed. This proposed algorithm utilizes variable-feedrate commands according to the curvature of machined surfaces. The proposed interpolator is evaluated and compared with the conventional method based on constant feedrates through computer simulation.

• 한국인터넷방송통신학회논문지
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• 제12권4호
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• pp.15-22
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• 2012

본 논문에서는 시분산 채널에서 발생되는 진폭과 위상 찌그러짐을 보상하기위한 적응 등화 알고리즘에서 MCMA와 MDD를 병렬 구조로 구현한 PMCMA-MDD (Paralled Modified Constant Modulus Algorithm-Modified Decision Directed)와 단일 구조로 구현한 DW-MCMA (Dual Weight-Modified Constant Modulus Algorithm)의 성능을 비교, 평가하였다. 이들 알고리즘은 기본적으로 MCMA와 RCA의 축소 신호점을 이용하는 비용 함수를 적용하여 빠른 수렴 속도와 적은 잔류 isi를 얻을 수 있다. 구조적으로 PMCMA-MDD 알고리즘은 2개의 독립적인 등화 필터를 병렬로 사용하며 DW-MCMA 알고리즘은 1개의 등화 필터를 이용하여 2번에 걸쳐 탭 계수를 갱신한다. 2가지 알고리즘에 대한 컴퓨터 시뮬레이션을 통해 수신측에서 복원된 신호 성상도, 잔류 isi 특성 곡선에의한 수렴 시간과 수렴 속도, 정규화 MSE 및 주어진 시분산 채널의 신호대 잡음비에서 SER (Symbol Error Rate)등의 성능을 비교하였으며, 시뮬레이션 결과 모든 성능에서 PMCMA-MDD가 DW-MCMA보다 우월함을 알 수 있었다.

• 통합자연과학논문집
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• 제15권3호
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• pp.99-110
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• 2022

Solar photovoltaic (PV) system shows a non-linear current (I) -voltage (V) characteristics, which depends on the surrounding environment factors, such as irradiance, temperature, and the wind. Solar PV system, with current (I) - voltage (V) and power (P) - Voltage (V) characteristics, specifies a unique operating point at where the possible maximum power point (MPP) is delivered. At the MPP, the PV array operates at maximum power efficiency. In order to continuously harvest maximum power at any point of time from solar PV modules, a good MPPT algorithms need to be employed. Currently, due to its simplicity and easy implementation, Perturb and Observe (P&O) algorithms are the most commonly used MPPT control method in the PV systems but it has a drawback at suddenly varying environment situations, due to constant step size. In this paper, to overcome the difficulties of the fast changing environment and suddenly changing the power of PV array due to constant step size in the P&O algorithm, least mean Square (LMS) methods is proposed together with P&O MPPT algorithm which is superior to traditional P&O MPPT. PV output power is predicted using LMS method to improve the tracking speed and deduce the possibility of misjudgment of increasing and decreasing the PV output. Simulation results shows that the proposed MPPT technique can track the MPP accurately as well as its dynamic response is very fast in response to the change of environmental parameters in comparison with the conventional P&O MPPT algorithm, and improves system performance.

• ETRI Journal
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• 제28권5호
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• pp.593-606
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• 2006

Thanks to the great possibilities of providing different types of telecommunication traffic to a large geographical area, satellite networks are expected to be an essential component of the next-generation internet. As a result, issues concerning the designing and testing of efficient connection-admission-control (CAC) strategies in order to increase the quality of service (QoS) for multimedia traffic sources, are attractive and at the cutting edge of research. This paper investigates the potential strengths of a generic digital-video-broadcasting return-channel-via-satellite (DVB-RCS) system architecture, proposing a new CAC algorithm with the aim of efficiently managing real-time multimedia video sources, both with constant and high variable data rate transmission; moreover, the proposed admission strategy is compared with a well-known iterative CAC mainly designed for the managing of real-time bursty traffic sources in order to demonstrate that the new algorithm is also well suited for those traffic sources. Performance analysis shows that, both algorithms guarantee the agreed QoS to real-time bursty connections that are more sensitive to delay jitter; however, our proposed algorithm can also manage interactive real-time multimedia traffic sources in high load and mixed traffic conditions.

• Industrial Engineering and Management Systems
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• 제9권3호
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• pp.262-274
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• 2010

This article investigates how to adaptively predict the time-varying metrology delay that could realistically occur in the semiconductor manufacturing practice. Metrology delays pose a great challenge for the existing run-to-run (R2R) controllers, driving the process output significantly away from target if not adequately predicted. First, the expected asymptotic double exponentially weighted moving average (DEWMA) control output, by using the EWMA and recursive least squares (RLS) prediction methods, is derived. It has been found that the relationships between the expected control output and target in both estimation methods are parallel, and six cases are addressed. Within the context of time-varying metrology delay, this paper presents a modified recursive least squares-linear trend (RLS-LT) controller, in combination with runs test. Simulated single input-single output (SISO) R2R processes subject to various time-varying metrology delay scenarios are used as a testbed to evaluate the proposed algorithms. The simulation results indicate that the modified RLS-LT controller can yield the process output more accurately on target with smaller mean squared error (MSE) than the original RLSLT controller that only deals with constant metrology delays.