• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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• pp.228-231
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• 2008

For a satellite data communication, the technology of frame synchronization is widely used between a sender and a receiver. Last year, we suggested zero-loss frame synchronization [1] using pattern search and using bits threshold search algorithm that is based on SIMD technology [2,3]. This algorithm could solve both of hardware and software drawbacks, which are frame loss and low processing performance. However, this algorithm didn't optimize the processing of output data, synchronized data, which caused overhead to the memory allocation and the memory copy. Consequently, the performance of the frame synchronizer application was degraded. In this paper, we enhance previous work using a circular buffer in order to optimize the output data processing. The performance comparison with the previous algorithm shows that the enhanced proposed approach dramatically outperforms in the output data processing speed.

• International Journal of Control, Automation, and Systems
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• 제6권3호
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• pp.386-393
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• 2008

A position control method for interpolating aspherical grinding and polishing tool path was reviewed and experimented in a nano precision machine. The position-base algorithm was reformed from the time-base algorithm, proposed in the previous study. The characteristics of the algorithm were in the velocity control loop with position feedback. The aspherical surface was divided by an interval at which each velocity and acceleration were calculated. The theoretical velocity was corrected by position error during processing. In the experiment, a machine was constructed and nano-scale linear encoders were installed at each axis. Relation between process parameters and the variation of position error was monitored and discussed. The best result from optimized parameters showed that the accuracy was 150nm and improved from the previous report.

• 제어로봇시스템학회논문지
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• 제14권2호
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• pp.111-117
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• 2008

This paper presents a new continuation-based quasi-steady-state(CQSS) time-domain simulation algorithm incorporating a multiplicative aggregated load model for power systems. The authors' previous paper introduced a CQSS algorithm, which has the robust convergent characteristic near the singularity point due to the application of a continuation method. The previous CQSS algorithm implemented the load restoration in power systems using the exponent-based load recovery model that is derived from the additive dynamic load model. However, the reformulated exponent-based model causes the inappropriate variation of short-term load characteristics when switching actions occur, during time-domain simulation. This paper depicts how to incorporate a multiplicative load restoration model, which does not have the problem of deforming short-term load characteristics, into the time simulation algorithm, and shows an illustrative example with a 39-bus test system.

• 대한전기학회논문지:시스템및제어부문D
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• 제50권9호
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• pp.447-453
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• 2001

In this paper, a new auto-focusing algorithm for digital cameras is proposed. One of the primary concerns of digital image processing is to increase image quality, and the most important factor for degrading the images is the blurring effect due to inexact focusing. The blurring effect occurs when the focusing lens is located on an unsuitable position. Therefore, focusing on an object should be proceeded before acquiring images. The proposed auto-focusing algorithm is MMDT(min-max difference threshold), and the performance of the proposed algorithm is evaluated by the use of the focus curve. It is shown that the proposed algorithm is superior to other previous auto-focusing algorithms in both the focus shape and computation time aspects. Especially, the improvement of the focus curve shape in both monotonousness and slope indicates that focusing can be done rapidly in comparison with other previous proposed algorithms.

• 한국정보처리학회논문지
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• 제6권9호
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• pp.2305-2310
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• 1999

동영상의 데이터베이스에서 원하는 영상검색을 위해 히스토그램을 이용한 알고리즘이 널리 사용되었다. 본 논문에서는 HVS(Human Visual System)의 특성을 이용한 히스토그램 알고리즘을 제안하였고 또한 기존의 알고리즘과 제안한 알고리즘의 성능을 분석하여 성능이 우수한 알고리즘을 제안한다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2006년도 춘계종합학술대회
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• pp.779-783
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• 2006

A The estimation of electrical power consumption is becoming more important to supply stabilized electrical power recently. In this paper, we propose a supplied forecasting system of electrical power using Fuzzy Compensative Algorithm to estimate electrical load accurately than the previous. We evaluate a time series of supplied electrical power have the chaotic character using quantitative and qualitative analysis, compose a forecasting system by the maximum change $rate(\alpha)$ of Fuzzy Algorithm and compensative parameter. Simulating it for obtained time series, we can obtain more accurate results than the previous proposed system.

• 한국국방경영분석학회지
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• 제27권2호
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• pp.25-36
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• 2001

In this paper a new heuristic algorithm has been developed and presented for logistics for multiple objectives in an automated manufacturing systems. We proposed Simallest Processing and Average setup time Ratio First(SPARF) algorithm for multiple criteria under sequence setup time. The heuristic algorithm is implemented on the various problem cases by number of jobs and machines. The proposed algorithm provided smaller than the previously documented heuristics. The results obtained show a superior solution by the new heuristic over previous heuristics on all problem sizes. we perform analyses of variance to fortify the above results of comparison with the previous algorithms to the four cases using Statistical Analysis System(SAS) package. The results show that the larger is the number of groups or cells, the bigger is the amount of improvement by the proposed algorithms. It suggests that the algorithms proposed is strongly influenced by the number of cells, groups and interaction of these factors.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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• pp.252-257
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• 2000

This paper describes a look-ahead algorithm of PCNC(personal computer numerical control). The algorithm is based on acceleration/deceleration before interpolation never including a command error and determines a velocity value in end point of each block(or start point of each block). The algorithm is represented as following; 1) calculating two maximum arrival velocity(v1, v2) by a acceleration value, a command velocity and distance in a previous block and a next block, 2) getting a tangent velocity(v3) of the adjacent blocks, 3) choosing a minimum value among these three velocities, and 4) setting the value to a velocity of a start point of the next block(or a end point of the previous block). The proposed look-ahead algorithm was implemented and tested by using a commercial RTOS(real time operation system) on the MS-Windows NT 4.0 in a PC platform. For interfacing to a machine, a counter board, a DAC board and a DIO board were used. The result of the algorithm increased a machining precision and a machining speed in many short blocks.

• 전자공학회논문지T
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• 제35T권2호
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• pp.13-19
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• 1998

가산잡음으로 훼손된 영상을 복원하는 Filter Algorithm 중 Mean Filter Algorithm은 화소들의 묶음을 산술평균한 값을 화소로 삼는다. 그러나 산술평균은 화소간의 편차를 고려하지 않으므로 편차가 심한 화소-윤곽선이 훼손되고, 화소들에 포함되지 않은 값이 화소로 채택될수 있다. 이를 보완한 Median Filter Algorithm은 화소들의 묶음을 정렬하여 중앙값을 화소로 삼아 편차가 심한 화소를 보존하고, 화소들에 포함되지 않은 값이 화소로 선택되는 오류를 방지한다. 그러나 Median Filter Algorithm은 화소들의 묶음을 정렬하고, 중위수를 구하는데 소모되는 시간이 Mean Filter Algorithm의 화소들의 평균을 구하는 시간보다 상대적으로 많이 소모되고, 잡음이 화소로 선택될 오류가 발생한다. 이러한 단점을 보완한 Fast Median Filter Algorithm을 제안한다. Fast Median Filter Algorithm은 훼손영상을 전체집합으로, 국부영상을 부분집합 1, 2로 두어 Median Filter Algorithm보다 효율적으로 화소들을 정렬한다. 시험결과는 IBM 기종(80586)에서 구동되었으며 기존의 Filter Algorithm들과 비교분석한 결과 Mean Filter Algorithm과 대등한 속도와 Median Filter Algorithm의 결과영상을 얻음으로서 Fast Median Filter Algorithm의 우수성을 확인할 수 있었다.

• 한국통신학회논문지
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• 제22권7호
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• pp.1394-1402
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• 1997

In this work, an efficient test algorithm and BIST architeture a for embedded memories are presented. The proposed test algorithm can fully detect stuck-at fault, transition fault, coupling fault. Moreover, the proposed test algorithm can detect nighborhood pattern sensitive fault which could not be detected in previous march test algoarithms. The proposed test algorithm perposed test algorithm performs testing for neghborhood pattern sensitive fault using backgroung data which has been used word-oriented memory testing.