• 전자공학회논문지A
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• 제30A권3호
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• pp.16-33
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• 1993

New decoding algorithm of double-error-correction Reed-Solmon codes over GF(2$^{8}$) for optical compact disks is proposed and decoding algorithm of RS codes with triple-error-correcting capability is presented in this paper. First of all. efficient algorithms for estimating the number of errors in the received code words are presented. The most complex circuits in the RS decoder are parts for soving the error-location numbers from error-location polynomial, so the complexity of those circuits has a great influence on overall decoder complexity. One of the most known algorithm for searching the error-location number is Chien's method, in which all the elements of GF(2$^{m}$) are substituted into the error-location polynomial and the error-location number can be found as the elements satisfying the error-location polynomial. But Chien's scheme needs another 1 frame delay in the decoder, which reduces decoding speed as well as require more stroage circuits for the received ocode symbols. The ther is Polkinghorn method, in which the roots can be resolved directly by solving the error-location polynomial. Bur this method needs additional ROM (readonly memory) for storing tthe roots of the all possible coefficients of error-location polynomial or much more complex cicuit. Simple, efficient, and high speed method for solving the error-location number and decoding algorithm of double-error correction RS codes which reudce considerably the complexity of decoder are proposed by using Hilbert theorems in this paper. And the performance of the proposed decoding algorithm is compared with that of conventional decoding algorithms. As a result of comparison, the proposed decoding algorithm is superior to the conventional decoding algorithm with respect to decoding delay and decoder complexity. And decoding algorithm of RS codes with triple-error-correcting capability is presented, which is suitable for error-correction in digital audio tape, also.

• 디지털산업정보학회논문지
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• 제10권4호
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• pp.151-160
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• 2014

In this paper, a comparison of superpixel characteristics based on SLIC(simple linear iterative clustering) for several color feature spaces is presented. Computer vision applications have come to rely increasingly on superpixels in recent years. Superpixel algorithms group pixels into perceptually meaningful atomic regions, which can be used to replace the rigid structure of the pixel grid. A superpixel is consist of pixels with similar features such as luminance, color, textures etc. Thus superpixels are more efficient than pixels in case of large scale image processing. Generally superpixel characteristics are described by uniformity, boundary precision and recall, compactness. However previous methods only generate superpixels a special color space but lack researches on superpixel characteristics. Therefore we present superpixel characteristics based on SLIC as known popular. In this paper, Lab, Luv, LCH, HSV, YIQ and RGB color feature spaces are used. Uniformity, compactness, boundary precision and recall are measured for comparing characteristics of superpixel. For computer simulation, Berkeley image database(BSD300) is used and Lab color space is superior to the others by the experimental results.

• 한국멀티미디어학회논문지
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• 제14권12호
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• pp.1591-1600
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• 2011

The skyline of a multidimensional data set is the maximal subset whose elements are not dominated by other elements of the set. Skyline computation is considered to be very useful for a decision making system that deals with multidimensional data analyses. Recently, a great deal of interests has been shown to improve the performance of skyline computation algorithms. In order to speedup, the number of comparisons between data elements should be reduced. In this paper, we propose a filter lining scheme to accomplish such objectives. The scheme divides the multidimensional data space into angle-based partitions, and places a filter for each partition, and then connects them together in order to establish the final filter line. The filter line can be used to eliminate data, that are not part of the skyline, from the original data set in the preprocessing stage. The filter line is adaptively improved during the data scanning stage. In addition, skylines are computed for each remaining data partition, and are then merged to form the final skyline. Our scheme is an improvement of the previously reported simple preprocessing scheme using simple filters. The performance of the scheme is shown by experiments.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.641-644
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• 2005

This study reveals some recent attempt in modeling empirically obtained B&K HATS (Head and Torso Simulator) HRTFs (Head Related Transfer Functions) to Isolate parameters that stimulate lateral and elevation perception. Localization using non-individual HRTFs often yields poor performance in synthesizing virtual sound sources when applied to a group of individuals due to differences in size and shape of head, pinnae, and torso. For realization of both effective and efficient virtual audio it is necessary to develop a method to tailor a given set of non-individual HRTFs to fit each listener without measuring his/her HRTF set. Pole-zero modeling is applied to fit HRIRs (Head Related Impulse Responses) and modeling criterions for determining suitable number of parameters are suggested for efficient modeling. Horizontal HRTFs are modeled as minimum-phase transfer functions with appropriate ITDs (Interaural Time Delay) obtained from RTF (Ray Tracing Formula) to better fit the size of listener's head for usage in simple virtualizer algorithms without complex regularization processes. Result of modeling HRTFs in the median plane is shown and parameters responsible for elevation perception are isolated which can be referred to in the future study of developing customizable HRTFs.

• 정보보호학회논문지
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• 제34권2호
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• pp.167-177
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• 2024

본 논문은 isogeny 기반 전자 서명 알고리즘인 SeaSign의 최적화 방안을 제안한다. SeaSign은 CSIDH의 class group action에 Fiat-Shamir with abort를 결합한 전자서명 알고리즘이다. CSIDH 기반 암호는 SIDH 기반 암호가 다항시간안에 공격됨에 따라 다시 주목받고 있지만, 이를 기반한 전자서명인 SeaSign은 비효율적인 속도로 많은 최적화가 진행되지 않았다. 본 논문에서는 SeaSign에 대한 효율적인 서명 방법을 제안한다. 제안하는 서명 방법은 간단하지만 강력하며, 알고리즘 내에서 rejection sampling의 위치 변경을 통해 이루어진다. 추가로, 본 논문에서는 제안하는 알고리즘이 최적 성능을 제공할 수 있는 파라미터를 제시한다. 제시한 결과, 기존 SeaSign의 파라미터를 사용할 경우, 본 논문에서 제안한 서명방법은 기존 SeaSign 대비 3배 빠른 성능을 보인다. 추가로 신규 제시된 파라미터와 본 논문의 서명 방법을 결합한 경우, 기존 SeaSign 대비 290배 빠른 성능과 Decru 등이 제안한 방법 대비 7.47배 빠른 성능을 제공한다.

• 한국융합학회논문지
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• 제9권2호
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• pp.13-18
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• 2018

본 논문은 다층을 갖는 네트워크를 가장 효율적으로 학습하는 것은 결국 최적의 가중치 벡터의 집합을 찾아가는 과정이라는 간단한 접근 방법을 기본으로 하고 있다. 일반적인 학습 문제의 단점을 극복하기 위해 제안 모델에서는 EBP와 OVSSA의 특징들을 결합한 방법을 사용한다. 즉 EBP가 지역 최소치에 빠질 수 있는 성질을 보강하기 위해 OVSSA의 확률이론으로 빠져나갈 수 있도록 제안 방법은 각각 알고리즘의 장점만을 취하여 하나의 모델을 구성한다. 제안 알고리즘에서는 EBP에서 오류를 줄이기 위한 방법들을 에너지함수로 사용하고, 이 에너지를 OVSSA로 최소화 하는 방법을 사용하였다. 두 가지의 상이한 성질을 가지는 알고리즘이 합쳐질 수 있음을 간단한 실험 결과를 통해 확인한다.

• 산업경영시스템학회지
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• 제32권1호
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• pp.79-84
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• 2009

In this paper, a best-first branch and bound algorithm based upon the bottom-up approach for the unweighted unconstrained two-dimensional cutting problem is proposed to find the optimal solution to the problem. The algorithm uses simple and effective methods to prevent constructing duplicated patterns and reduces the searching space by dividing the branched node set. It also uses a efficient bounding strategy to fathom the set of patterns. Computational results are compared with veil-known exact algorithms and demonstrate the efficiency of the proposed algorithm.

• Journal of information and communication convergence engineering
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• 제14권4호
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• pp.240-245
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• 2016

Scalable video streaming over wireless networks has many challenges. The most significant challenge is related to packet loss. To overcome this problem, in this paper, we propose an unequal loss protection (ULP) method using a new forward error correction (FEC) mechanism for robust scalable video streaming over wireless networks. For an efficient FEC assignment considering video quality, we first introduce a simple and efficient performance metric, the layer-based recovery rate (LRR), for quantifying the unequal error propagation effects of the temporal and quality layers on the basis of packet losses. LRR is based on the unequal importance in both the temporal and the quality layers of a hierarchical scalable video coding structure. Then, the proposed ULP-LRR method assigns an appropriate number of FEC packets on the basis of the LRR to protect the video layers against packet lossy network environments. Compared with conventional ULP algorithms, the proposed ULP-LRR algorithm demonstrates a higher performance for various error-prone wireless channel statuses.

• Advances in robotics research
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• 제2권2호
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• pp.151-159
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• 2018

The evolution of bipedal robots was the foundation stone for development of Humanoid robots. The highly complex and non-linear dynamic of human walking made it very difficult for researchers to simulate the gait patterns under different conditions. Simple controllers were developed initially using basic mechanics like Linear Inverted Pendulum (LIP) model and later on advanced into complex control systems with dynamic stability with the help of high accuracy feedback systems and efficient real-time optimization algorithms. This paper illustrates a number of significant mathematical models and controllers developed so far in the field of bipeds and humanoids. The key facts and ideas are extracted and categorized in order to describe it in a comprehensible structure.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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• pp.384-387
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• 2003

Most of the real world phenomena change over time. The ability to represent and to reason geographic data becomes crucial. A large amount of non-standard applications are dealing with data characterized by spatial, temporal and/or uncertainty features. Non-standard data like spatial and temporal data have an inner complex structure requiring sophisticated data representation, and their operations necessitate sophisticated and efficient algorithms. Current GIS technology is inefficient to model and to handle complex geographic phenomena, which involve space, time and uncertainty dimensions. This paper concentrates on developing a fuzzy spatio-temporal data model based on fuzzy set theory and relational data models. Fuzzy spatio-temporal operators are also provided to support dynamic query.