• Title/Summary/Keyword: Adaptive weight

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Supplier Evaluation in Green Supply Chain: An Adaptive Weight D-S Theory Model Based on Fuzzy-Rough-Sets-AHP Method

  • Li, Lianhui;Xu, Guanying;Wang, Hongguang
    • Journal of Information Processing Systems
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    • v.15 no.3
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    • pp.655-669
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    • 2019
  • Supplier evaluation is of great significance in green supply chain management. Influenced by factors such as economic globalization, sustainable development, a holistic index framework is difficult to establish in green supply chain. Furthermore, the initial index values of candidate suppliers are often characterized by uncertainty and incompleteness and the index weight is variable. To solve these problems, an index framework is established after comprehensive consideration of the major factors. Then an adaptive weight D-S theory model is put forward, and a fuzzy-rough-sets-AHP method is proposed to solve the adaptive weight in the index framework. The case study and the comparison with TOPSIS show that the adaptive weight D-S theory model in this paper is feasible and effective.

Filtering Motion Vectors using an Adaptive Weight Function (적응적 가중치 함수를 이용한 모션 벡터의 필터링)

  • 장석우;김진욱;이근수;김계영
    • Journal of KIISE:Software and Applications
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    • v.31 no.11
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    • pp.1474-1482
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    • 2004
  • In this paper, we propose an approach for extracting and filtering block motion vectors using an adaptive weight function. We first extract motion vectors from a sequence of images by using size-varibale block matching and then process them by adaptive robust estimation to filter out outliers (motion vectors out of concern). The proposed adaptive robust estimation defines a continuous sigmoid weight function. It then adaptively tunes the sigmoid function to its hard-limit as the residual errors between the model and input data are decreased, so that we can effectively separate non-outliers (motion vectors of concern) from outliers with the finally tuned hard-limit of the weight function. The experimental results show that the suggested approach is very effective in filtering block motion vectors.

An Improved Stereo Matching Algorithm with Robustness to Noise Based on Adaptive Support Weight

  • Lee, Ingyu;Moon, Byungin
    • Journal of Information Processing Systems
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    • v.13 no.2
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    • pp.256-267
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    • 2017
  • An active research area in computer vision, stereo matching is aimed at obtaining three-dimensional (3D) information from a stereo image pair captured by a stereo camera. To extract accurate 3D information, a number of studies have examined stereo matching algorithms that employ adaptive support weight. Among them, the adaptive census transform (ACT) algorithm has yielded a relatively strong matching capability. The drawbacks of the ACT, however, are that it produces low matching accuracy at the border of an object and is vulnerable to noise. To mitigate these drawbacks, this paper proposes and analyzes the features of an improved stereo matching algorithm that not only enhances matching accuracy but also is also robust to noise. The proposed algorithm, based on the ACT, adopts the truncated absolute difference and the multiple sparse windows method. The experimental results show that compared to the ACT, the proposed algorithm reduces the average error rate of depth maps on Middlebury dataset images by as much as 2% and that is has a strong robustness to noise.

General Linearly Constrained Broadband Adaptive Arrays in the Eigenvector Space

  • Chang, Byong Kun
    • Journal of information and communication convergence engineering
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    • v.15 no.2
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    • pp.73-78
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    • 2017
  • A general linearly constrained broadband adaptive array is examined in the eigenvector space with respect to the optimal weight vector and the adaptive algorithm. The optimal weight vector and the general adaptive algorithm in the eigenvector space are obtained by eigenvector matrix transformation. Their operations are shown to be the same as in the standard coordinate system except for the relevant transformed vectors and matrices. The nulling performance of the general linearly constrained broadband adaptive array depends on the gain factor such that the constraint plane is shifted perpendicularly to the origin by an increase in the gain factor. The general linearly constrained broadband adaptive array is observed to perform better than a conventional linearly constrained adaptive array in a coherent signal environment, while the former performs similarly to the latter in a non-coherent signal environment.

Wideband Jamming Signal Remove Using Adaptive Array Algorithm (적응배열 알고리즘을 이용한 광대역 재밍 신호 제거)

  • Lee, Kwan-Hyeong
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.12 no.4
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    • pp.419-424
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    • 2019
  • In this paper, we proposed an algorithm to estimate the desired target in wideband jamming signal environment. In order to suppress the jamming signal, we use the spatial time adaptive algorithm and QR decomposition to obtain the optimal weight. The spatial time adaptive algorithm of adaptive array antenna system multiplies the tap delay signal by a complex weight to obtain a weight. In order to minimize the power consumption because of the inverse matrix, optimal weight is obtained by using QR decomposition. Through simulation, we compare and analyze the performance of the proposed algorithm and the existing algorithm. In the target estimation of [-40o,0o,+40o], the proposed algorithm estimated all three targets, but the existing algorithm estimated only [0o] due to of the jamming signal. We prove that the proposed algorithm improves performance by removing the jamming signal and estimating the target accurately.

A Weight Map Based on the Local Brightness Method for Adaptive Unsharp Masking (적응형 언샤프 마스킹을 위한 지역적 밝기 기반의 가중치 맵 생성 기법)

  • Hwang, Tae Hun;Kim, Jin Heon
    • Journal of Korea Multimedia Society
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    • v.21 no.8
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    • pp.821-828
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    • 2018
  • Image Enhancement is used in various applications. Among them, unsharp masking methods can improve the contrast with a simple operation. However, it has problems of noise enhancement and halo effect caused by the use of a single filter. To solve this problems, adaptive processing using multi-scale and bilinear filters is being studied. These methods are effective for improving the halo effect, but it require a lot of calculation time. In this paper, we want to simplify adaptive filtering by generating a weight map based on local brightness. This weight map enables adaptive processing that eliminates the halo effect through a single multiplication operation. Through experiments, we confirmed the suppression of the halo effect through the result image of the proposed algorithm and existing algorithm.

Optimum Array Processing with Variable Linear Constraint

  • Chang, Byong Kun
    • Journal of information and communication convergence engineering
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    • v.12 no.3
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    • pp.140-144
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    • 2014
  • A general linearly constrained adaptive array is examined in the weight vector space to illustrate the array performance with respect to the gain factor. A narrowband linear adaptive array is implemented in a coherent signal environment. It is shown that the gain factor in the general linearly constrained adaptive array has an effect on the linear constraint gain of the conventional linearly constrained adaptive array. It is observed that a variation of the gain factor of the general linearly constrained adaptive array results in a variation of the distance between the constraint plane and the origin in the translated weight vector space. Simulation results are shown to demonstrate the effect of the gain factor on the nulling performance.

A Modified Robust Adaptive Beamformer for Microphone Arrays

  • Lee, Young-Ho;Choi, Su-Young;Park, Jans-Sik;Son, Kyung-Sik
    • Proceedings of the Korea Multimedia Society Conference
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    • 2003.05b
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    • pp.446-449
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    • 2003
  • The conventional GSC is inappropriate in real situation when the target signal is present. The steering vector error cancels the target signal and the target signal misadjusts the weight of the adaptive filter. To prevent the target signal cancellation, the robust GSC using the constrained adaptive filters was already proposed. However, the adaptive weight misadjustment is not settled in robust GSC. This Paper proposes a revised robust sidelobe canceller with adaptive compensator. To compensate the influence of target signal, the adaptive compensator is used in cascade. In computer simulation, we show the performance improvement by comparing the robust GSC with the proposed GSC.

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A Study on the Optimum Weight Vector of Linearly Constrained Conditions (선형 제한 조건의 최적 가중 벡터에 대한 연구)

  • Shin, Ho-Sub
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.5
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    • pp.101-107
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    • 2011
  • The optimum weight vector is studied to remove interference and jamming signals in adaptive array antenna system. The optimum weight vector is calculated to apply a minimum variance algorithm and cost function in linearly constrained conditions, and accurately estimates target's signal. Adaptive array antenna system is the system which improves signal to noise ratio(SNR) and decreases interference and jammer power. Adaptive array antenna system delays at tap output of antenna array element. Each tap finally makes the complex signal of one in multiplier complex weight. In order to obtain optimum's weight calculation, optimum weight vector is used in this paper. After simulation, resolution is increased below $3^{\circ}$, and sidelobe is decreased about 10 dB.

A Dynamic Ensemble Method using Adaptive Weight Adjustment for Concept Drifting Streaming Data (컨셉 변동 스트리밍 데이터를 위한 적응적 가중치 조정을 이용한 동적 앙상블 방법)

  • Kim, Young-Deok;Park, Cheong Hee
    • Journal of KIISE
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    • v.44 no.8
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    • pp.842-853
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    • 2017
  • Streaming data is a sequence of data samples that are consistently generated over time. The data distribution or concept can change over time, and this change becomes a factor to reduce the performance of a classification model. Adaptive incremental learning can maintain the classification performance by updating the current classification model with the weight adjusted according to the degree of concept drift. However, selecting the proper weight value depending on the degree of concept drift is difficult. In this paper, we propose a dynamic ensemble method based on adaptive weight adjustment according to the degree of concept drift. Experimental results demonstrate that the proposed method shows higher performance than the other compared methods.