• 전자공학회논문지B
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• 제33B권8호
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• pp.42-49
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• 1996

In this paper, we propose a satellite multispectral image data compression method using classified vector quantization. This method classifies each pixel vector considering band characteristics of multispectral images. For each class, we perform both intraband and interband vector quantization to romove spatial and spectral redundancy, respectively. And residual vector quantization for error images is performed to reduce error of interband vector quantization. Thus, this method improves compression efficiency because of removing both intraband(spatial) and interband (spectral) redundancy in multispectral images, effectively. Experiments on landsat TM multispectral image show that compression efficiency of proposed method is better than that of conventional method.

• 한국통신학회논문지
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• 제22권8호
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• pp.1722-1732
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• 1997

In this paper, we propose a coding method of remotely sensed satellite image data using region classification and interband correlation. This method classifies each pixel vector consider spectral characteristics. Then we perform the classified intraband VQ to remove spatial (intraband redundancy for a reference band image. To remove interband redundancy effectively, we perform the classified interband prediction for the band images that the high correlation spectrally and perform the classified interband VQ for the remaining band images. Experiments on LANDSAT TM image show that the coding efficiency of the proposed method is better than that of the conventional Gupta's method. Especially, this method removes redundancies effectively for satellite iamge including various geographical objects and for and images that have low interband correlation.

• 한국컴퓨터그래픽스학회논문지
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• 제5권1호
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• pp.11-17
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• 1999

Example guided inverse kinematics (EGIK)는 기존의 역운동학(inverse kinematics)을 확장, 향상시키는 알고리즘이다. 기존의 역운동학은 모델자체의 redundancy에 기인하여 jerky한 동작을 만들어내는 단점이 있다. EGIK에서는 미리 측정된 동작데이타를 효과적으로 이용하여 이러한 redundancy문제를 해결한다. 이 때 end-effector 위치 차이와 관절각의 차이를 동시에 최소화하기 위해서 비선형 최적화 기술이 사용된다. 우리는 결과로서의 동작이 원래의 동작의 특성을 잘 보존하는 자연스러운 것임을 보인다. EGIK는 기존의 동작 데이타를 이용하여 다관절체의 동작을 생성해내는 효과적인 기술이다.

• 항공우주기술
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• 제13권2호
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• pp.38-46
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• 2014

CRC (Cyclic Redundancy Codes)는 데이터 전송 시 오류 발생 유무를 검출하기 위한 하나의 방법으로, 정지궤도복합위성(GEO-KOMPSAT 2B) 개발에서는 정지궤도환경탑재체와 위성 간의 GRDDP (GOES-R Reliable Data Delivery Protocol)에 사용되고 있다. 본 논문에서는 CRC를 구현할 때 널리 사용하는 테이블 기반 CRC의 원리를 소개하고, 이를 기반으로 환경탑재체 개발에서 사용 중인 CRC8을 소프트웨어로 구현한 결과를 설명한다.

• Transactions on Control, Automation and Systems Engineering
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• 제2권1호
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• pp.56-61
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• 2000

Majority of industrial robots are controlled by a simple independent joint control of joint actuators rather than complex controllers based on the nonlinear dynamic model of the robot manipulator. In this independent joint control scheme, the performance of actuator control is influenced significantly by the joint disturbance torques including gravity, Coriolis and centrifugal torques, which result in the trajectory tracking error in the joint control system. The control performance of a redundant manipulator under independent joint control can be improved by minimizing this joint disturbance torque in resolving the kinematic redundancy. A 3 DOF planar robot is studied as an example, and the dynamic programming method is used to find the globally optimal joint trajectory that minimize the joint disturbance torque over the entire motion. The resulting solution is compared with the solution obtained by the conventional joint torque minimization, and it is shown that joint disturbance can be reduced using the kinematic redundancy.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2606-2609
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• 2004

As computer system has developed, the break down rate of system has been increased. So, engineers have been interested in reliability of system. General method that is used to heighten reliability of system is Redundancy of System by dual switching control. In this paper, we propose DSCM which can give Redundancy structure in existent PC(Microsoft Window 2000 OS) base system. And we experiment redundancy structure that is applied DSCM to currently using train control in IFC(Interface Computer) system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.155.4-155
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• 2001

This paper deals with the inertia property-based redundancy resolution in posture control of a mobile manipulator. As a measure for the redundancy resolution of a mobile manipulator, an effective inertia at the end effector in the operational space is proposed and investigated. The reduced effective inertia has a significant effect on reducing the impulse force in collision with environment. To find a posture satisfying both the reduced inertia and joint limit constraints, we propose a combined potential function method that can deal with multiple constraints. The proposed reduced inertia property algorithm is integrated into a damping controller to reduce the impulse force at collision and to regulate the contact force in mobile manipulation ...

• Journal of Advanced Marine Engineering and Technology
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• 제38권2호
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• pp.225-232
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• 2014

The traditional RAP (Redundancy Allocation Problem) of complex systems has considered only the redundancy of subsystem with homogeneous components. In this paper we extend it as a RAP of complex systems with heterogeneous components which is more flexible than the case of homogeneous components. We model this problem as a nonlinear integer programming problem, find its optimal solution by tabu search, and suggest an example of the efficient reliability design with heterogeneous components. In order to improve the quality of the solution of the tabu search, we suggest a modified tabu search to employ an adaptive procedure (1-opt or 2-opt exchange) to generate the efficient neighborhood solutions. Computational results show that our modified procedure obtains better solutions as the size of problem increases from 30 to 50, even though it requires rather more computing time. With some adjustment of the parameters of the proposed method, it can be applied to the optimal reliability designs of complex systems of ships.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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• pp.452-455
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• 1995

Various physical limitations which intrinsically exist in the manipulator control system, for example kinematic limits and torque limit, cause some undesirable effects. Specifically, when one or more actuators are saturated the expected control performance can not be anticipated and in some cases it induces instability of the system. The effect of torque limit, especially for redundant manipulators, is studied in this article, and an analytic method to reconstruct the control input using the redundancy is proposed based on the kinematically decomposed modeling of redundant manipulators. It results to no degradation of the output motion closed-loop dynamics at the cost of the least degradation of the null motion closed-loop dynamics. Numerical simulations help to verify the advantages of the proposed scheme.

• 한국자동차공학회논문집
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• 제11권2호
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• pp.89-95
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• 2003

We consider a problem of application of analytical redundancy to engine synchronization process of spark ignition engines, which is critical to timing for every ECU process including ignition and injection. The engine synchronization process we consider here is performed using the pulse signal obtained by the revolution of crankshaft trigger wheel (CTW) coupled to crank shaft. We propose a discrete-time linear model for the signal, for which we construct FDI (Fault Detection & Isolation) system consisting residual generator and threshold based on linear observer.