• Title/Summary/Keyword: 임의시간

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An Efficient Classifying Recognition Algorithm of Printed and handwritten numerals (인쇄체 및 필기체 숫자의 효율적인 구분 인식 알고리즘)

  • 홍연찬
    • Journal of the Korean Institute of Intelligent Systems
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    • v.9 no.5
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    • pp.517-525
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    • 1999
  • In this paper, we propose efficient total recognition system of handwritten and printed numerals for reducing the classification time. The proposed system consists of two-step neuroclassifier : Printed numerals classifier and handwritten numerals classifier. In the proposed scheme, the printed numerals classifier classifies the printed numerals rapidly with single MLP neural network by low-order feature vector and rejects handwritten numerals. The handwritten numerals classifier classifies the handwritten numerals which is rejected in printed numerals classifier with modularized cluster neural network by complex feature vector. In order to verify the performance of the proposed method,handwritten numerals database of NIST and printed numerals database which include various fonts are used in the experiments. In case of using the proposed classifier, the overall classification time was reduced by 49.1% - 65.5% in comparison of the existent handwritten classifier.

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Substream-based out-of-sequence packet scheduling for streaming stored media (저장매체 스트리밍에서 substream에 기초한 비순차 패킷 스케줄링)

  • Choi Su Jeong;Ahn Hee June;Kang Sang Hyuk
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.10C
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    • pp.1469-1483
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    • 2004
  • We propose a packet scheduling algorithms for streaming media. We assume that the receiver periodically reports back the channel throughput. From the original video data, the importance level of a video packet is determined by its relative position within its group of pictures, taking into account the motion-texture discrimination and temporal scalability. Thus, we generate a number of nested substreams. Using feedback information from the receiver and statistical characteristics of the video, we model the streaming system as a queueing system, compute the run-time decoding failure probability of a Same in each substream based on effective bandwidth approach, and determine the optimum substream to be sent at that moment in time. Since the optimum substream is updated periodically, the resulting sending order is different from the original playback order. From experiments with real video data, we show that our proposed scheduling scheme outperforms the conventional sequential sending scheme.

An Economic Ship Routing System by Optimizing Outputs of Engine-Power based on an Evolutionary Strategy (전화전략기반 엔진출력 최적화를 통한 선박경제운항시스템)

  • Jang, Ho-Seop;Kwon, Yung-Keun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.4B
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    • pp.412-421
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    • 2011
  • An economic ship routing means to sail a ship with a goal of minimizing the fuel consumption by utilizing weather forecast information, and many such systems have been recently developed. Most of them assume that sailing is carried out with a constraint like a fixed output of engine-power or a fixed sailing speed. However, if the output of engine-power is controlled, it is possible to reduce the fuel consumption by sailing a ship under a relatively good weather condition. In this paper, we propose a novel economic ship routing system which can search optimal outputs of the engine-power for each part of a path by employing an evolutionary strategy. In addition, we develope an AA algorithm to find the shortest path and a method to enhance the degree of curve representation. These make the proposed system applicable to an arbitrary pair of departure and destination points. We compared our proposed system with another existing system not controlling output of the engine-power over 36 scenarios in total, and observed that the former reduced the estimated fuel consumption than the latter by 1.3% on average and the maximum 5.6% with little difference of estimated time of arrival.

SAW Filter Transmission Characteristics Design with Genetic Algorithm

  • Park, Kyu­-Chil;Kim, Seok­-Jae
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.8
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    • pp.1767-1775
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    • 2003
  • The SAW device is extensively used as a electro.mechanical band­pass filter in which a two­pairs of interdigital transducers are provided over the surface of the piezoelectric substrate. For the design requirement, the central frequency and the bandwidth of the passband, and the attenuation level of the stopband region are specified. The configuration is made so as to satisfy the specification given. The central frequency is mainly determined by the distance between the pair of the finger electrodes. The design is considered as an optimization problem with which the error norm, the distance between the desired characteristics and the calculated for a given model is to be minimized. The delta function model and the electrical equivalent circuit model are utilized to represent the SAW filter characteristics. Genetic algorithm is used for optimization in which apodization of the transducer fingers is chosen as a design variable.

Location Estimation Algorithm with TDOA Scheme in Real Time Location System (RTLS에서 TDOA 기법을 이용한 위치추정 알고리즘)

  • Jeong, Seung-Hee;Kang, Chul-Gyu;Oh, Chang-Heon;Lim, Choon-Sik
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.2
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    • pp.459-462
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    • 2005
  • In this paper, we investigate the high precision location estimation algorithm in 2.45GHz band RTLS with multiple tags. The location is estimated in LOS environments, 300m × 300m area, and 2D coordinates adopting a TDOA scheme which is not necessitate the transmission time of tags. We evaluate the average estimation error in distance assuming that tags are randomly distributed and the readers(38) are uniformly(equal space) placed in test area. In results, average estimation error is 3.12m and 1.47m at reader numbers of 4 and 8, respectively. Minimum estimation error is obtained when the accumulated receiving signal from a tag is 3 or 4 regardless of available reader numbers. The error is less than 3m, satisfies the specification of RTLS.

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A Study on the Evaluation of MPEG-4 Video Decoding Complexity for HDTV (HDTV를 위한 MPEG-4 비디오 디코딩 복잡도의 평가에 관한 연구)

  • Ahn, Seong-Yeol;Park, Won-Woo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.2
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    • pp.595-598
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    • 2005
  • MPEG-4 Visual is, and international standard for the object-based video compression, designed for supporting a wide range of applications from multimedia communication to HDTV. To control the minimum decoding complexity required at the decoder, the MPEG-4 Visual standard defines the co-called video buffering mechanism, which includes three video buffer models. Among them, the VCV(Video Complexity Verifier) defines the control of the processing speed for decoding of a macroblock, there are two models: VCV and B-VCV distinguishing the boundary and non-boundary MB. This paper presents the evaluation results of decoding complexity by measuring decoding time of a MB for rectangular, arbitrarily shaped video objects and the various types of objects supporting the resolution of HDTV using the optimized MPEG-4 Reference Software. The experimental results shows that decoding complexity varies depending on the coding type and more effective usage of decoding resources may be possible.

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Numerical Analysis of Wave Impact Forces in Numerical Wave Basin (수치파 수조를 이용한 파랑 충격력 수치해석)

  • Shin, Young-Seop;Hong, Key-Yong
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.1
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    • pp.205-210
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    • 2006
  • The impact forces of the highly nonlinear waves are one of the important factors in designing the ocean structures. The impact forces are very difficult to analyze numerically and experimentally because they are impulsive in magnitude and occur instantaneously. In this study the numerical program based on N.S. equations are used to investigate the impact forces of steep waves where the waves are gene rated by the wave maker in the numerical wave basin. The arbitrary steep waves are generated by the superposition of waves of single frequency and the impact forces on vertical cylinder are simulated on the multiblock grids. V.O.F. and the local height function methods are used to track the free surfaces. To validate the numerical analysis the numerical results are compared with the experimental ones and the acceptable agreements are found. It is thought that more studies on the simulations of the incoming breaking waves and the impact forces on the vertical cylinder should be made to obtain the useful results to be applied in the offshore design.

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A Stochastic Word-Spacing System Based on Word Category-Pattern (어절 내의 형태소 범주 패턴에 기반한 통계적 자동 띄어쓰기 시스템)

  • Kang, Mi-Young;Jung, Sung-Won;Kwon, Hyuk-Chul
    • Journal of KIISE:Software and Applications
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    • v.33 no.11
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    • pp.965-978
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    • 2006
  • This paper implements an automatic Korean word-spacing system based on word-recognition using morpheme unigrams and the pattern that the categories of those morpheme unigrams share within a candidate word. Although previous work on Korean word-spacing models has produced the advantages of easy construction and time efficiency, there still remain problems, such as data sparseness and critical memory size, which arise from the morpho-typological characteristics of Korean. In order to cope with both problems, our implementation uses the stochastic information of morpheme unigrams, and their category patterns, instead of word unigrams. A word's probability in a sentence is obtained based on morpheme probability and the weight for the morpheme's category within the category pattern of the candidate word. The category weights are trained so as to minimize the error means between the observed probabilities of words and those estimated by words' individual-morphemes' probabilities weighted according to their categories' powers in a given word's category pattern.

A Fast K-means and Fuzzy-c-means Algorithms using Adaptively Initialization (적응적인 초기치 설정을 이용한 Fast K-means 및 Frizzy-c-means 알고리즘)

  • 강지혜;김성수
    • Journal of KIISE:Software and Applications
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    • v.31 no.4
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    • pp.516-524
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    • 2004
  • In this paper, the initial value problem in clustering using K-means or Fuzzy-c-means is considered to reduce the number of iterations. Conventionally the initial values in clustering using K-means or Fuzzy-c-means are chosen randomly, which sometimes brings the results that the process of clustering converges to undesired center points. The choice of intial value has been one of the well-known subjects to be solved. The system of clustering using K-means or Fuzzy-c-means is sensitive to the choice of intial values. As an approach to the problem, the uniform partitioning method is employed to extract the optimal initial point for each clustering of data. Experimental results are presented to demonstrate the superiority of the proposed method, which reduces the number of iterations for the central points of clustering groups.

A study on the Control Method of Single-Phase APF Using RRF Method (회전좌표계를 이용한 단상능동전력필터의 제어방법에 관한 연구)

  • 김영조;허진석;김영석
    • The Transactions of the Korean Institute of Power Electronics
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    • v.8 no.6
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    • pp.576-584
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    • 2003
  • This paper presents a new control method of single-phase active power filter(APF) for the compensation of harmonic current components in nonlinear loads. Constructing a imaginary second-phase giving time delay to load currents, making single-phase system into the system that has two phases, complex calculation is possible. In the previous method, it made a imaginary-phase lagged to the load current T/4(here T is the fundamental cycle), but in proposed method, the new signal, which has the delayed phase through the filter, using the phase-delay property of low-pass filter, was used to the second phase. Instantaneous calculation of harmonic current is possible, because two phase have different phase. In this paper, it was done with instantaneous calculation using the rotating reference frames(RRF) that synchronizes with source-frequency, a reference of compensation currents, not applying to instantaneous reactive power theory which uses the existed fixed reference frames. The simulation and experiment about R-L loads using the current source were carried out, and the effect of the proposed method was preyed through the result of this experiment.