• Title/Summary/Keyword: strong robustness

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Negative Exponential Disparity Based Deviance and Goodness-of-fit Tests for Continuous Models: Distributions, Efficiency and Robustness

  • Jeong, Dong-Bin;Sahadeb Sarkar
    • Journal of the Korean Statistical Society
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    • v.30 no.1
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    • pp.41-61
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    • 2001
  • The minimum negative exponential disparity estimator(MNEDE), introduced by Lindsay(1994), is an excellenet competitor to the minimum Hellinger distance estimator(Beran 1977) as a robust and yet efficient alternative to the maximum likelihood estimator in parametric models. In this paper we define the negative exponential deviance test(NEDT) as an analog of the likelihood ratio test(LRT), and show that the NEDT is asymptotically equivalent to he LRT at the model and under a sequence of contiguous alternatives. We establish that the asymptotic strong breakdown point for a class of minimum disparity estimators, containing the MNEDE, is at least 1/2 in continuous models. This result leads us to anticipate robustness of the NEDT under data contamination, and we demonstrate it empirically. In fact, in the simulation settings considered here the empirical level of the NEDT show more stability than the Hellinger deviance test(Simpson 1989). The NEDT is illustrated through an example data set. We also define a goodness-of-fit statistic to assess adequacy of a specified parametric model, and establish its asymptotic normality under the null hypothesis.

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A Fast and Robust Algorithm for Fighting Behavior Detection Based on Motion Vectors

  • Xie, Jianbin;Liu, Tong;Yan, Wei;Li, Peiqin;Zhuang, Zhaowen
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.5 no.11
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    • pp.2191-2203
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    • 2011
  • In this paper, we propose a fast and robust algorithm for fighting behavior detection based on Motion Vectors (MV), in order to solve the problem of low speed and weak robustness in traditional fighting behavior detection. Firstly, we analyze the characteristics of fighting scenes and activities, and then use motion estimation algorithm based on block-matching to calculate MV of motion regions. Secondly, we extract features from magnitudes and directions of MV, and normalize these features by using Joint Gaussian Membership Function, and then fuse these features by using weighted arithmetic average method. Finally, we present the conception of Average Maximum Violence Index (AMVI) to judge the fighting behavior in surveillance scenes. Experiments show that the new algorithm achieves high speed and strong robustness for fighting behavior detection in surveillance scenes.

Local Similarity based Discriminant Analysis for Face Recognition

  • Xiang, Xinguang;Liu, Fan;Bi, Ye;Wang, Yanfang;Tang, Jinhui
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.11
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    • pp.4502-4518
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    • 2015
  • Fisher linear discriminant analysis (LDA) is one of the most popular projection techniques for feature extraction and has been widely applied in face recognition. However, it cannot be used when encountering the single sample per person problem (SSPP) because the intra-class variations cannot be evaluated. In this paper, we propose a novel method called local similarity based linear discriminant analysis (LS_LDA) to solve this problem. Motivated by the "divide-conquer" strategy, we first divide the face into local blocks, and classify each local block, and then integrate all the classification results to make final decision. To make LDA feasible for SSPP problem, we further divide each block into overlapped patches and assume that these patches are from the same class. To improve the robustness of LS_LDA to outliers, we further propose local similarity based median discriminant analysis (LS_MDA), which uses class median vector to estimate the class population mean in LDA modeling. Experimental results on three popular databases show that our methods not only generalize well SSPP problem but also have strong robustness to expression, illumination, occlusion and time variation.

Efficient secret sharing scheme with cheater identification based on QR code

  • Huang, Peng-Cheng;Chang, Chin-Chen;Li, Yung-Hui;Liu, Yanjun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.10
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    • pp.5144-5160
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    • 2019
  • Secret sharing is an effective way of protecting secret messages. However, the traditional secret sharing schemes are considered meaningless due to malicious people attention which might raise risks. To overcome the weakness, this paper presents an effective secret sharing scheme with the functionality of cheater identification, based on meaningful QR code. The secret message will be split and concealed in the padding region of cover QR codes with the assistance of Latin square and it can be completely restored when all the involved participants cooperate. The concealing strategy exploits the characteristic of Reed-Solomon (RS) code to ensure the strong robustness of generated QR code pseudo-shares. The meaningful QR code pseudo-shares help to reduce the curious of unrelated persons. Some experiments were done to evaluate the performance of proposed scheme. The results showed that the proposed scheme is feasible, efficient and secure compared to the other existing schemes. It also achieves a higher secret payload and maintains stronger robustness.

Digital Watermarking of Medical Images (의료영상의 디지털 워터마킹)

  • Lee, Sang-Bock;Lee, Sam-Yol;Lee, Jun-Haeng
    • Journal of radiological science and technology
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    • v.27 no.2
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    • pp.13-19
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    • 2004
  • This study proposes how to insert a strong watermark creating a big change in the areas of edge and texture. While conversion by existing Fourier transformation can acquire information for all ranges of frequency domain from the image, Wavelet transformation can manipulate edge and texture area selectively. Therefore, through wavelet transformation concerned area may be selected and watermarks in copyright formation are inserted. Our proposed algorithm was compared to Xia's watermarking technique using wavelet transformation. Its fidelity and robustness were tested with attack methods used in existing papers and it turns out that the proposed algorithm using HVS properties is more superior to Xia's techniques.

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Collapse simulations of a long span transmission tower-line system subjected to near-fault ground motions

  • Tian, Li;Pan, Haiyang;Ma, Ruisheng;Qiu, Canxing
    • Earthquakes and Structures
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    • v.13 no.2
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    • pp.211-220
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    • 2017
  • Observations from past strong earthquakes revealed that near-fault ground motions could lead to the failure, or even collapse of electricity transmission towers which are vital components of an overhead electric power delivery system. For assessing the performance and robustness, a high-fidelity three-dimension finite element model of a long span transmission tower-line system is established with the consideration of geometric nonlinearity and material nonlinearity. In the numerical model, the Tian-Ma-Qu material model is utilized to capture the nonlinear behaviours of structural members, and the cumulative damage D is defined as an index to identify the failure of members. Consequently, incremental dynamic analyses (IDAs) are conducted to study the collapse fragility, damage positions, collapse margin ratio (CMR) and dynamic robustness of the transmission towers by using twenty near-fault ground motions selected from PEER. Based on the bending and shear deformation of structures, the collapse mechanism of electricity transmission towers subjected to Chi-Chi earthquake is investigated. This research can serve as a reference for the performance of large span transmission tower line system subjected to near-fault ground motions.

Automated Body-Fitted Grid Generation Method with Application to Natural Convection Problem (자동화된 경계고정좌표 생성법과 자연대류 문제에 대한 적용)

  • Choi, IL Kon;Maeng, Joo Sung
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.23 no.6
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    • pp.703-712
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    • 1999
  • This paper suggests an automatic elliptic grid generation method that is well-suited for the numerical mapping of complex geometries which are easily obtained from general CAD programs. An LBLADI solver is used for the governing mapping equations to have the strong diagonal dominance. The full boundary control method is adopted to determine the control functions of the equations, which allows the control of the grid regarding spacing and angle control at all boundary surfaces. The solution method presented here provides the capability of mapping very complicated geometries by defining grid point locations only along the boundaries. In the automated elliptic grid generation procedure, it is showed that strong diagonal dominance is essential to achieve successful mapping irrespective of the initial grid condition provided. To demonstrate the robustness of this method, it is applied to the thermal flow like the natural convection between eccentric cylinders. The results agree well with others.

A Study of Economic Value Added Disclosures in the Annual Reports: Is EVA a Superior Measure of Corporate Performance?

  • Bhasin, Madan Lal
    • East Asian Journal of Business Economics (EAJBE)
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    • v.5 no.1
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    • pp.10-26
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    • 2017
  • This paper explains the concept of Economic Value Added (EVA) that is gaining popularity in India. We also examine whether EVA is a superior performance measure, both for corporate disclosure and for internal governance. Of late, companies in India have started focusing on shareholders wealth creation by adopting value-based models for measuring shareholder value that helps to align managerial decision-making with the firm preferences. In recent years, the EVA framework is gradually replacing the 'traditional' measures of financial performance on account of its robustness and its immunity from 'creative' accounting. Even though some leading Indian companies have already joined the band wagon of their American counterparts in adapting the EVA-based corporate performance systems, many other are hesitating as there is no strong evidence that the EVA system works in India. Till now, EVA disclosures are "not mandatory for the Indian companies." Also, we examine the value-creation strategies of selected Indian companies by analyzing whether EVA better represents the market-value of these companies in comparison to conventional performance measures. The study indicates that "there is no strong evidence to support Stern Stewart's claim that EVA is superior to the traditional performance measures in its association with MVA." As part of this study, we have also extensively surveyed the EVA disclosures in the Annual Reports made by the same sample group of 500 corporations from India.

Economic Globalization and Financial Development: Empirical Evidence from India and Sri Lanka

  • BEHERA, Chinmaya
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.5
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    • pp.11-19
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    • 2021
  • The paper examines the nexus between economic globalization, financial development and institutional reform in India and Sri Lanka during the period 1990-2017. Using the panel ARDL method, the study finds the long-run relationship between financial development, economic globalization, and institutional reforms. From the short-run equation, the study finds the negative and statistically significant impact of economic globalization on financial development in India whereas Sri Lanka has a positive impact of institutional quality on financial development. Then, the study finds no short-run causality between financial development, economic globalization and institutional reforms. However, the study finds bi-direction strong causality between economic globalization and financial development. Further, the study finds uni-directional strong causality from institutional quality to financial development and economic globalization. Moreover, there is an existence of long-run causality between financial development, economic globalization and institutional quality. For the robustness of the results, the study considers the financial market as a proxy for financial development. Then, the study applies the panel ARDL test and find the consistency in the results. The policymakers in India and Sri Lanka should focus on institutional reforms so that it can reap the benefit of economic globalization. In turn, the quality of institutional reforms can thereby lead to financial development.

A study on ESD Protection circuit based on 4H-SiC MOSFET (4H-SiC MOSFET기반 ESD보호회로에 관한 연구)

  • Seo, Jeong-Ju;Do, Kyoung-Il;Seo, Jeong-Ju;Kwon, Sang-Wook;Koo, Yong-Seo
    • Journal of IKEEE
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    • v.22 no.4
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    • pp.1202-1205
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    • 2018
  • In this paper, we proposed ggNMOS based on 4H-SiC material and analyzed its electrical characteristics. 4H-SiC is a wide band-gap meterial, which is superior in area contrast and high voltage characteristics to Si material, and is attracting attention in the power semiconductor field. The proposed device has high robustness and strong snapback characteristics. The process consisted of SiC process and electrical characteristics were analyzed by TLP measurement equipment.