• Journal of the Korean Institute of Telematics and Electronics C
• /
• v.35C no.9
• /
• pp.1-10
• /
• 1998

This paper is to propose an algorithm named as DYSAC to find the critical path(the longest sensitizable path) in a large digital circuit, whose purpose is to reduce the time to find critical path and to find critical paths of the circuits for which the previous methods could not find one. Also a set of path sensitization criteria named as DYPSEC is proposed, which is used to select a path from input to the output inside the DYSAC. The DYSAC consists of two sub-algorithms; the level assignment algorithm to assign a level to each node and the critical path selection algorithm to select the sensitizable path. The proposed algorithm was implemented with C-language on SUN Sparc and applied to the ISCAS'85 benchmark circuits to make sure if it works correctly and finds the correct critical path. Also, the results from the experiments were compared to the results from the previous works. The comparison items were the ability to find the critical path and the speed, in both of which the proposed algorithm in this paper shows better results than others.

• Korean Journal of Optics and Photonics
• /
• v.16 no.1
• /
• pp.43-49
• /
• 2005

In this paper, we propose a method for optimizing a computer-generated hologram(CGH) by combining the Tabu Search(TS) algorithm with the Simulated Annealing(SA) algorithm. By replacing an initial random pattern of the SA algorithm with an approximately ideal hologram pattern of the TS algorithm, we design a CGH which has high diffraction efficiency(DE). We compared the performance of the proposed algorithm with the SA algorithm using computer simulation and an optical experiment. As a result, we confirmed diffraction efficiency and uniformity to be enhanced in the proposed algorithm.

• Journal of Korea Water Resources Association
• /
• v.42 no.3
• /
• pp.259-270
• /
• 2009

The applicability of the developed distributed rainfall runoff model using a multi-directional flow allocation algorithm and a real-time updating algorithm was evaluated. The rainfall runoff processes were simulated for the events of the Andong dam basin and the Namgang dam basin using raingauge network data and weather radar rainfall data, respectively. Model parameters of the basins were estimated using previous storm event then those parameters were applied to a current storm event. The physical propriety of the multi-directional flow allocation algorithm for flow routing was validated by presenting the result of flow grouping for the Andong dam basin. Results demonstrated that the developed model has efficiency of simulation time with maintaining accuracy by applying the multi-directional flow allocation algorithm and it can obtain more accurate results by applying the real-time updating algorithm. In this study, we demonstrated the applicability of a distributed rainfall runoff model for the advanced basin-wide flood management.

• Journal of IKEEE
• /
• v.6 no.1 s.10
• /
• pp.94-101
• /
• 2002

In this paper, we propose a motion estimation algorithm for the discontinuity blocks. The algorithm uses sub-SAD value (i.e. the sum of absolute difference for a quarter of a block) to identify the discontinuity region, and produces additional motion vectors for these sub-blocks if necessary. We show with experimental results that, in comparison with some conventional motion estimation algorithms, the proposed algorithm achieves quality enhancement for the sequences with discontinuity blocks, and also shows the same computational quantity as to normal algorithms for sequences with less discontinuity.

• Journal of Internet Computing and Services
• /
• v.10 no.6
• /
• pp.19-26
• /
• 2009

In this paper, a minimum Euclidian distance criterion between error PDF and Dirac delta function is introduced and a constant modulus type blind equalizer algorithm based on the criterion is proposed. The proposed algorithm using constant modulus error in place of actual error term of the criterion has superior convergence and steady state MSE performance, and the error signal of the proposed algorithm exhibits more concentrated density function in blind equalization environments. Simulation results indicate that the proposed method can be a reliable candidate for blind equalizer algorithms for multipoint communications.

• Proceedings of the Korea Multimedia Society Conference
• /
• 2002.05d
• /
• pp.726-729
• /
• 2002

웹은 이제 우리 생활의 일부분이 되어 가고 있다. 많은 사람들이 웹을 이용하여 중요한 정보를 얻고 있으며, 이로 인하여 많은 콘텐츠들이 개발되고 있다. 그 중 학습을 목적으로 하는 교육 콘텐츠도 개발되고 있는데, 이러한 개발은 교육 및 훈련이 쉽고, 원하는 시간에 반복 학습이 가능하기 때문에 많이 이루어지고 있다. 본 연구에서는 알고리듬의 이해를 도와 주는 JAVA 프로그램을 개발하게 되었다. 웹에서의 구현을 위해 JAVA를 사용하였으며, 기존의 많은 알고리듬 중 정렬 알고리듬을 내용으로 하는 교육 콘텐츠를 개발하게 되었다.

• The Journal of the Acoustical Society of Korea
• /
• v.20 no.4
• /
• pp.22-28
• /
• 2001

This paper describes the implementation of a robust speaker position location system using the voice signal received by microphone array. To be robust to the reverberation which is the major factor of the performance degradation, low-frequency phase restoration algorithm which eliminates the influence of reverberations using the low-frequency information of the CPSP function is proposed. The implemented real-time system consists of a general purpose DSP (TMS320C31 of Texas instruments), analog part which contains amplifiers and filters, and digital part which is composed of the external memory and 12-bit A/D converter. In the real conference room environment, the implemented system that was constructed by the proposed algorithms showed better performance than the conventional system. The error of the TDOA estimation reduced more than 15 samples.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.40 no.12
• /
• pp.59-70
• /
• 2003

Proposed CCRSVP (Candidate Casting RSVP) algorithm is a new fast handoff method which uses advanced multicasting method and RSVP for IEEE 802.11 Wireless LAN (WLAN) environments. The proposed algorithm shows good performance in the handoff latency and the B/W efficiency aspect and guarantees QoS because it uses L2 information (BSSID) of WLAN and starts to reserve resources and multicast packets before L2 handoff completes. We also propose a Markov chain performance analysis model in which we can analyze the handoff performance of various handoff algorithms. Using the model, we compare bandwidth efficiency of the proposed algorithm with existing handoff algorithms which use RSVP by analyzing blocking probability of session, resource usage, and the average number of ongoing session in a cell. The results show that the proposed algorithm shows better performance than the existing algorithms in the above three performance aspects.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.44 no.2 s.314
• /
• pp.93-101
• /
• 2007

To jointly optimize the spatial registration and the exposure compensation, an iterative registration algorithm, the Lucas-Kanade algorithm, is combined with an exposure compensation algorithm, which is based on the histogram transformation function. Based on a simple regression model, a nonparametric estimator, the empirical conditional mean, and its polynomial fitting are used as histogram transformation functions for the exposure compensation. Since the proposed algorithm is composed of separable optimization phases, the proposed algorithm is more advantageous than the joint approaches of Mann and Candocia in the aspect of implementation flexibility. The proposed algorithm performs a better registration for real images than the case of registration that does not consider the exposure difference.

• The Journal of the Acoustical Society of Korea
• /
• v.22 no.4
• /
• pp.293-298
• /
• 2003

In this paper. we propose a fast search algorithm for nearest neighbor vector quantization (NNVQ). The proposed algorithm rejects those codewords which can not be the nearest codeword and reduces the search range of codebook. Hence it reduces computational time and complexity in encoding process, while it provides the same SD performance as the conventional full search algorithm. We apply the proposed algorithm to the adaptive multi-rate (AMR) speech coder and a general vector quantizer designed by LBG. algorithm. Simulation results show effectiveness of the proposed algorithm.