• Title/Summary/Keyword: Robustness

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On the Robustness of $L_1$-estimator in Linear Regression Models

  • Bu-Yong Kim
    • Communications for Statistical Applications and Methods
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    • v.2 no.2
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    • pp.277-287
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    • 1995
  • It is well kmown that the $L_1$-estimator is robust with respect to vertical outliers in regression data, even if it is susceptible to bad leverage points. This article is concerned with the robustness of the $L_1$-estimator. To investigate its robustness against vertical outliers we may find intervals for the value of the response variable within which the $L_1$-estimates do not shange. A procedure for constructing those intervals in multiple limear regression is illustrated in the sensitivity analysis context. And then vertical breakdown point of the $L_1$-estimator is defined on the basis of properties related to those intervals.

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Robustness of Complete Diallel cross designs with a Single Missing Observation

  • Kwon, Yong-Man;Lee, Jang-Jae
    • Journal of Integrative Natural Science
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    • v.5 no.2
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    • pp.135-138
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    • 2012
  • The reduction of efficiency of missing observations on complete diallel cross designs are examined. we studies robustness of optimal block designs for estimating general combining ability against loss of missing observations in diallel cross. A-efficiencies suggest that these designs are fairly robust. Simple g-inverses may be found for the information matrices of the line effects which allow evaluation of expressions for the variances of the differences between the pairs of line effects with missing observations. we numerically calculate the reduction of efficiency for estimating general combining ability against loss of missing observations in diallel cross.

Multi-layer Neural Network with Hybrid Learning Rules for Improved Robust Capability (Robustness를 형성시키기 위한 Hybrid 학습법칙을 갖는 다층구조 신경회로망)

  • 정동규;이수영
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.31B no.8
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    • pp.211-218
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    • 1994
  • In this paper we develope a hybrid learning rule to improve the robustness of multi-layer Perceptions. In most neural networks the activation of a neuron is deternined by a nonlinear transformation of the weighted sum of inputs to the neurons. Investigating the behaviour of activations of hidden layer neurons a new learning algorithm is developed for improved robustness for multi-layer Perceptrons. Unlike other methods which reduce the network complexity by putting restrictions on synaptic weights our method based on error-backpropagation increases the complexity of the underlying proplem by imposing it saturation requirement on hidden layer neurons. We also found that the additional gradient-descent term for the requirement corresponds to the Hebbian rule and our algorithm incorporates the Hebbian learning rule into the error back-propagation rule. Computer simulation demonstrates fast learning convergence as well as improved robustness for classification and hetero-association of patterns.

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New GGNMOS I/O Cell Array for Improved Electrical Overstress Robustness

  • Pang, Yon-Sup;Kim, Youngju
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.13 no.1
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    • pp.65-70
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    • 2013
  • A 0.18-${\mu}m$ 3.3 V grounded-gate NMOS (GGNMOS) I/O cell array for timing controller (TCON) application is proposed for improving electrical overstress (EOS) robustness. The improved cell array consists of 20 GGNMOS, 4 inserted well taps, 2 end-well taps and shallow trench isolation (STI). Technology computer-aided design (TCAD) simulation results show that the inserted well taps and extended drain contact gate spacing (DCGS) is effective in preventing EOS failure, e.g. local burnout. Thermodynamic models for device simulation enable us to obtain lattice temperature distributions inside the cells. The peak value of the maximum lattice temperature in the improved GGNMOS cell array is lower than that in a conventional GGNMOS cell array. The inserted well taps also improve the uniformity of turn-on of GGNMOS cells. EOS test results show the validity of the simulation results on improvement of EOS robustness of the new GGNMOS I/O cell array.

High Embedding Capacity and Robust Audio Watermarking for Secure Transmission Using Tamper Detection

  • Kaur, Arashdeep;Dutta, Malay Kishore
    • ETRI Journal
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    • v.40 no.1
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    • pp.133-145
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    • 2018
  • Robustness, payload, and imperceptibility of audio watermarking algorithms are contradictory design issues with high-level security of the watermark. In this study, the major issue in achieving high payload along with adequate robustness against challenging signal-processing attacks is addressed. Moreover, a security code has been strategically used for secure transmission of data, providing tamper detection at the receiver end. The high watermark payload in this work has been achieved by using the complementary features of third-level detailed coefficients of discrete wavelet transform where the human auditory system is not sensitive to alterations in the audio signal. To counter the watermark loss under challenging attacks at high payload, Daubechies wavelets that have an orthogonal property and provide smoother frequencies have been used, which can protect the data from loss under signal-processing attacks. Experimental results indicate that the proposed algorithm has demonstrated adequate robustness against signal processing attacks at 4,884.1 bps. Among the evaluators, 87% have rated the proposed algorithm to be remarkable in terms of transparency.

Improved Reliable SVD-Based Watermark Scheme For Ownership Verification (소유권 확인을 위한 향상된 고신뢰성 SVD 기반 워터마킹기법)

  • Luong, Ngoc Thuy Dung;Sohn, Won
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2016.11a
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    • pp.82-84
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    • 2016
  • We propose a new reliable SVD-based watermarking scheme having high fidelity and strong robustness with no false-positive problem. Each column of the principal component of a watermark image is embedded into singular values of LL, LH, HL and HH sub-bands of cover image with different scale factors. Each scale factor is optimized by trading-off fidelity and robustness using Differential Evolution (DE) algorithm. The proposed scheme improves fidelity and robustness of existing reliable SVD based watermarking schemes without any false-positive problem. Index Terms - watermarking, reliable SVD, DWT, principal component, Differential Evolution.

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Adaptive Neural Network Control for Robot Manipulators

  • Lee, Min-Jung;Choi, Young-Kiu
    • KIEE International Transaction on Systems and Control
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    • v.12D no.1
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    • pp.43-50
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    • 2002
  • In the recent years neural networks have fulfilled the promise of providing model-free learning controllers for nonlinear systems; however, it is very difficult to guarantee the stability and robustness of neural network control systems. This paper proposes an adaptive neural network control for robot manipulators based on the radial basis function netwo.k (RBFN). The RBFN is a branch of the neural networks and is mathematically tractable. So we adopt the RBFN to approximate nonlinear robot dynamics. The RBFN generates control input signals based on the Lyapunov stability that is often used in the conventional control schemes. The saturation function is also chosen as an auxiliary controller to guarantee the stability and robustness of the control system under the external disturbances and modeling uncertainties.

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A Analysis on the Effect of the Controller Design due to Performance Index (평가지표에 따른 제어기 설계 영향 분석)

  • Yoo, Hang-Youal;Lee, Jung-Kuk;Lee, Keum-Won;Lee, Jun-Mo
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2004.05a
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    • pp.90-94
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    • 2004
  • Among various modern control theories, PID control has been well used for several decades. PID algorithms needs son tuning methods are used for selecting PID parameters. But in some cases various kinds of performance indices are used instead of well-known tuning rules, and so variable type of performance index must be tested so that controllers, output characteristics and disturbance rejection property meets some specifications. In this paper, linear conbinational type of performance using error signal, time, control input and robustness is used to the PID control of air conditioning system. By the 2 DOF PID parmeters minimizing perfromacne index, controllers, output characteristics and robustness properties are analyzed. Simulations are done with MATLAB m file and mdl files.

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A Study on Analysis of Error Correction Code in Server System (서버 시스템 내의 오류 정정 코드 분석에 관한 연구)

  • Lee, Chang-Hwa
    • Journal of the Korea Institute of Military Science and Technology
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    • v.8 no.3 s.22
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    • pp.42-50
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    • 2005
  • In this paper, a novel method is proposed how the ECC(Error Correction Code) in server system can be investigated and the robustness of each system against noisy environment and element failure in memory module has been verified. Chipset manufacturers have hided the algorithm of their Hamming code and the user has difficulty in verification of the robustness of each system. The proposed method is very simple, but the outputs of the experiment explain the core ability of error correction in server system and helps the detection of the failure element. On the basis of these results, we could expect the robustness of digitalized weapon system and the efficient design of our own error correction code.

High Performance Control of Induction Motor Drive using GAT (GAT를 이용한 유도전동기 드라이브의 고성능 제어)

  • Ko, Jae-Sub;Choi, Jung-Sik;Chung, Dong-Hwa
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.55 no.2
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    • pp.78-82
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    • 2006
  • This paper is proposed genetic algorithm tuning(GAT) control)or for high performance of induction motor drive. We employed GA to the classical PI controller. The approach having ability for global optimization and with good robustness, is expected to overcome some weakness of conventional approaches and to be more acceptable for industrial practices. The control performance of the GAT PI controller is evaluated by analysis for various operating conditions. The results of experiment prove that the proposed control system has strong high performance and robustness to parameter variation, and steady-state accuracy and transient response.