• Title/Summary/Keyword: LS-method

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An Iterative Local Search Algorithm for Rural Postman Problems (Rural Postman Problem 해법을 위한 Iterative Local Search 알고리즘)

  • 강명주
    • Journal of the Korea Society of Computer and Information
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    • v.7 no.1
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    • pp.48-53
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    • 2002
  • This paper Proposes an iterative Local Search (ILS) algorithm for Rural Postman Problems (RPPs). LS searches neighbors from an initial solution in solution space and obtains a nearoptimal solution which can be a local-minima. As an extension of LS, the ILS algorithm is a method that uses various initial solutions for LS. Hence. ILS can overcome the defect of LS. This paper proposes LS and ILS methods for 18 RPPs and analyzes the results of LS and ILS. In the simulation results, the ILS method obtained the better results than the LS method.

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LS-SVM for large data sets

  • Park, Hongrak;Hwang, Hyungtae;Kim, Byungju
    • Journal of the Korean Data and Information Science Society
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    • v.27 no.2
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    • pp.549-557
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    • 2016
  • In this paper we propose multiclassification method for large data sets by ensembling least squares support vector machines (LS-SVM) with principal components instead of raw input vector. We use the revised one-vs-all method for multiclassification, which is one of voting scheme based on combining several binary classifications. The revised one-vs-all method is performed by using the hat matrix of LS-SVM ensemble, which is obtained by ensembling LS-SVMs trained using each random sample from the whole large training data. The leave-one-out cross validation (CV) function is used for the optimal values of hyper-parameters which affect the performance of multiclass LS-SVM ensemble. We present the generalized cross validation function to reduce computational burden of leave-one-out CV functions. Experimental results from real data sets are then obtained to illustrate the performance of the proposed multiclass LS-SVM ensemble.

Mixed-effects LS-SVR for longitudinal dat

  • Cho, Dae-Hyeon
    • Journal of the Korean Data and Information Science Society
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    • v.21 no.2
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    • pp.363-369
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    • 2010
  • In this paper we propose a mixed-effects least squares support vector regression (LS-SVR) for longitudinal data. We add a random-effect term in the optimization function of LS-SVR to take random effects into LS-SVR for analyzing longitudinal data. We also present the model selection method that employs generalized cross validation function for choosing the hyper-parameters which affect the performance of the mixed-effects LS-SVR. A simulated example is provided to indicate the usefulness of mixed-effect method for analyzing longitudinal data.

Development of a GIS Method for the Automatic Calculation of LS Factor of USLE (GIS를 이용한 USLE 지형인자(LS) 자동계산 방법에 관한 연구)

  • 우창호;황국웅
    • Journal of the Korean Institute of Landscape Architecture
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    • v.26 no.3
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    • pp.162-177
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    • 1998
  • Conentionally, LS factor for the USLE suggested by Wischmeier has been computed manually on topographic maps based on one dimensional approach. But outcomes of the equation could be severely affected by the convergence and divergence of surface runoff at complex terrains. Thus the objective of this research are to develop a method to automatically compute LS factor based on the multiple flow algorithm, and to test the accuracy of this method by comparing outcomes of this method to previous measurements or estimations of soil erosion. The program for the automatic calculation of LS factor was developed by utilizing Fox Pro 4.5, and outcomes of the program is designed to input to IDRISI. The accuracy test of LS factor was carried out by comparing the actual measurements of soil loss at two test sites in and around of Suwon. The calculated volume of soil erosion at Buju mountain, Mokpo, was also compared to the outcome of a previous research based on the LS factor calculated by the conventional onedimensional approach. The outcomes of this research are as follows. First, the computed L based on the multiple flow algorithm for concae slopes are greater than those of convex slopes,. Second, the estimated soil loss based on this method at the test site in Mokpo is much greater than the outcomes based on the conventional one-dimensional approach. It can e concluded that the application of this automatic calculation method of LS factor can improve the accuracy of USLE and facilitate soil erosion prevention methods.

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The effects of grouping method on mathematical achievement and attitude toward mathematics (집단구성이 수학 성취도와 수학에 대한 태도에 미치는 영향)

  • Seo Jong-Jin;Park Dal-Won
    • Journal of the Korean School Mathematics Society
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    • v.8 no.2
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    • pp.145-165
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    • 2005
  • The present study was investigate the effects of grouping method on mathematical achievement and attitude toward mathematics. The result of this study are as following. Referring to the improvement of mathematics achievement, TL-LS group I and II turns out to be more efficient than the normal learning groupIII(p<.05), there found no significant differ between TL-LS group I and II (p>.05). As for the level of mathematics achievement, TL-LS group II show more efficient than the normal learning groupIII at a medium and low level(p<.05), and TL-LS group I show more efficient than the normal learning groupIII at a low level(p>.05). As for the attitude toward mathematics, TL-LS group I and II turns out to be more efficient than the normal learning groupIII(p<.05), there found no significant differ between TL-LS group I and II (p>.05).

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LS code pair setting and sequential allocation methods

  • Wook, Roh-Dong
    • Proceedings of the IEEK Conference
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    • 2001.06a
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    • pp.221-224
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    • 2001
  • A new code: LS code was proposed for IMT-2000 CDMA system. The code has special properties during a certain time of interval: 1) perfect autocorrelation 2) perfect crosscorrelation. The perfect autocorrelation means that the autocorrelation has nMaximum for zero time-offset and zero for other times during a certain time. Moreover the perfect crosscorrelation means that the crosscorrelation has zero during a time of interest. In the LAS-DMA system, the LS code is only used in the spreading of data bits in contrast to the conventional CDMA system. Therefore the LS code pair setting and allocation order should be dealt with carefully considering the special properties of LS code. This paper is intended as an investigation of the setting LS code pair and the sequential allocation method. Firstly, the optimum LS code pair set is proposed in order to minimize PAPR. Secondly, the sequential allocation method is studied to either minimize PAPR or expand IFW.

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Pilot Symbol Assisted Low Complexity LS Channel Estimation for OFDM in Fast Time Varying Channels (고속 시변 채널 OFDM을 위한 파일럿 심볼을 이용한 저복잡도 LS 채널 예측)

  • Lim, Dong-Min
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.48 no.11
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    • pp.17-21
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    • 2011
  • In this paper, we propose a pilot symbol assisted low complexity LS channel estimation method for OFDM in fast time varying channels. The proposed method shows low complexity characteristics in terms of memory space and processing time compared with conventional BEM channel model LS estimation methods.

Regularized LS Signal Detection for OFDM in Fast Time Varying Channels (고속 시변 채널 OFDM을 위한 안정화된 LS 신호검출)

  • Lim, Dongmin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.1
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    • pp.83-85
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    • 2016
  • The OFDM with LS signal detection performs worse in fast time varying channels as the channel matrix has higher chance of becoming ill-conditioned. Various regularization methods are applied to avoid performance degradation in LS signal detection. In this paper, we proposed a CGLS method with the stopping criteria imposed by the characteristics of the modulation method, which shows performance comparable to that of the optimal LMMSE.

The effect of starvation on the characteristics of morphometric measurement and body-sectioned shape in Far Eastern catfish (Silurus asotus) (메기(Silurus asotus) 기아 시 외부형태 및 체 절단면 변화)

  • Park, In-Seok;Goo, In Bon;Gil, Hyun Woo
    • Korean Journal of Environmental Biology
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    • v.39 no.1
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    • pp.55-67
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    • 2021
  • A 210-day experiment was conducted to examine the effects of starvation on survival, external morphometric traits, and sectioned morphometric traits in Far Eastern catfish(Silurus asotus). The survival rate decreased to 92.2±0.47% in the fed group and to 74.4±2.59% in the starved group. Eight dimensions of Ls, DALPO/Ls, DADOP/Ls, ED/Ls, CH/Ls, BDAA/Ls, BDMA/Ls, and BWAA/Ls showed significant differences (p<0.05), and 16 other dimensions of DALAD/Ls, DPDPL/Ls, HPLAA/Ls, HALAV/Ls, HALOP/Ls, DAUPO/Ls, DADAV/Ls, DADAA/Ls, Max BL/Ls, Man BL/Ls, LD/Ls, HWOP/Ls, DAUF/HL, DAUS/HL, IW/HL, and DAUE/HL were not significantly different among the initial, fed, and starved groups (p>0.05). The fed group showed higher total height (THX), wider width (WX), and larger area (AX) than those of the starved group in each body section. This research provides information on the morphometric traits and body sections of starved Far Eastern catfish. These results can be used as a basic guide to indicate nutritional status and assist in aquaculture methods for Far Eastern catfish. Moreover, the methods used in this study were considered helpful because the survey analysis method can be used to investigate information on the nutritional status of other fish species.

Improving JPEG-LS Performance Using Location Information

  • Woo, Jae Hyeon;Kim, Hyoung Joong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.11
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    • pp.5547-5562
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    • 2016
  • JPEG-LS is an international standard for lossless or near-lossless image-compression algorithms. In this paper, a simple method is proposed to improve the performance of the lossless JPEG-LS algorithm. With respect to JPEG-LS and its supplementary explanation, Golomb-Rice (GR) coding is mainly used for entropy coding, but it is not used for long codewords. The proposed method replaces a set of long codewords with a set of shorter location map information. This paper shows how efficiently the location map guarantees reversibility and enhances the compression rate in terms of performance. Experiments have also been conducted to verify the efficiency of the proposed method.