• 제목/요약/키워드: Robustness Index

검색결과 135건 처리시간 0.027초

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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    • 제5권11호
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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.

Robustness of Selection Indices in Murrah Buffaloes

  • Gandhi, R.S.;Joshi, B.K.
    • Asian-Australasian Journal of Animal Sciences
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    • 제17권2호
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    • pp.159-163
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    • 2004
  • Data pertaining to first lactation records of 316 Murrah buffaloes, progeny of 47 sires, maintained at NDRI Farm for a period of 18 years were analysed to construct selection indices and to examine their robustness by changing the relative economic values of different economic traits. A total of 120 selection indices were constructed for three sets of relative economic values ( 40 for each set) considering different combinations of seven first lactation traits viz. age at first calving (AFC), first lactation 305 day or less milk yield (FLMY), first lactation length (FLL), first calving interval (FCI), milk yield per day of first lactation length (MY/FLL), milk yield per day of first calving interval (MY/FCI) and milk yield per day age at second calving (MY/ASC). The three sets of relative economic values were based on economic values of different traits, 1% standard deviation of different traits and regression of different traits on FLMY. The 'optimum' indices for the first two sets had five traits each namely AFC, FLMY, FLL, FCI and MY/ASC giving improvement in aggregate genotype of Rupees 269.11 and Rs. 174.88, respectively. The accuracy of selection from both indices was 70.79 and 69.39%, respectively. The 'best' selection index from the third set of data again had five traits (AFC, FLMY, FLL, FCI and MY/FLL) giving genetic gain of Rs. 124.16 and accuracy of selection of 71.81%. The critcal levels or break-even points for FLMY for varying levels of AFC and FCI estimated from the "optimum index" suggested the need of enhancement of present production level of the herd or reduction of AFC or FCI. It was concluded that economic values of various first lactation traits were the most appropriate to construct selection indices as compared to other criteria of assigning relative economic weights in Murrah buffaloes.

강인한 이산관측기 설계 (Robust Discrete-Time Observer Design)

  • 허건수;김상진
    • 한국정밀공학회지
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    • 제15권4호
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    • pp.134-140
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    • 1998
  • The authors have shown that the performance of discrete-time observer-based monitoring systems can be represented by the performance index k$_2$(P) (condition number of the eigensystem P of the observer matrix in terms of L$_2$ norm). The observers with the minimized performance index can be defined as robust observers in the sense that the observer performance can be guaranteed in harsh environments. In this paper, based on the performance index, a design methodology for the robust discrete-time observer is developed. Similar to the continuous-time case, the methodology determines the structure and eigenvalues of the observer matrix simultaneously. A complete design procedure is given for single-output case and is illustrated with a spindle-driver example. The simulation results demonstrate the improved performance compared with a traditional pole-placement observer technique.

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회복탄력성을 고려한 기상 시나리오별 가뭄 용수 공급방안: 나주호를 중심으로 (Water Supply Alternatives for Drought by Weather Scenarios Considering Resilience: Focusing on Naju Reservoir)

  • 박진현;고재한;조영준;정경훈;성무홍;정형모;박현규;유승환;윤광식
    • 한국농공학회논문집
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    • 제60권5호
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    • pp.115-124
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    • 2018
  • Resilience has been widely used in various fields including design and operation of infrastructures. The resilient infrastructures not only reduce the damage scale of various disasters but also reduce the time and cost required for restoration. However, resilience rarely applied to promote efficient management of agricultural infrastructures. Recently, drought is an aggravating disaster by climate change and need countermeasures. Therefore, we tried to demonstrate evaluating measures in case of drought under consideration of resilience. This study applied the robustness-cost index (RCI) to evaluate alternative solution of the supply problem of a large agricultural reservoir under drought conditions. Four structural alternatives were selected to estimate the robustness index (RI) and the cost index (CI) to obtain the RCI values. Structural alternatives are classified into temporary measures and permanent measures. Temporary measures include the development of a tube wells and the installation of the portable pump, while the permanent measures include the installation of a pumping stations and the pumping water to the reservoir (Yeongsan River-Naju reservoir). RCI values were higher in permanent measures than those of temporary measures. Initial storage of the reservoir also affected RCI values of the drought measures. Permanent measures installation and management of early stage of the reservoir storage shortage was identified as the most resilient system.

설계 민감도와 신뢰도 분석에 근거한 전자기기의 다목적 최적화 (Multi-Objective Optimization of Electromagnetic Device Based on Design Sensitivity Analysis and Reliability Analysis)

  • 렌지얀;장전해;박찬혁;고창섭
    • 전기학회논문지
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    • 제62권1호
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    • pp.49-56
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    • 2013
  • In this paper, for constrained optimization problem, one multi-objective optimization algorithm that ensures both performance robustness and constraint feasibility is proposed when uncertainties are involved in design variables. In the proposed algorithm, the gradient index of objective function assisted by design sensitivity with the help of finite element method is applied to evaluate robustness; the reliability calculated by the sensitivity-assisted Monte Carlo simulation method is used to assess the feasibility of constraint function. As a demonstration, the performance and numerical efficiency of the proposed method is investigated through application to the optimal design of TEAM problem 22--a superconducting magnetic energy storage system.

고유구조를 이용한 다중출력 시스템의 강인한 관측기 설계 (Robust Observer Design for Multi-Output Systems using Eigenstructure)

  • 허건수;남준철
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2003년도 춘계학술대회 논문집
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    • pp.39-44
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    • 2003
  • It was shown that the robustness of deterministic observers with respect to modeling errors, measurement bias and round-off errors can be represented by a single performance index the condition number of the observer eigenvector matrix. In this paper, a robust observer for multi-output systems is designed using the left eigenstructure assignment, where the observer gain can not be determined uniquely with respect to the desired observer poles. Utilizing the eigenstructuer assignment for the robustness of the observer, the desired eigenvector matrix is selected to achieve the observer eigenvector matrix with the small condition number. The performance of the designed robust observer is evaluated in a spindle-drive simulation example where the load speed to be estimated based on the measured signals.

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Construction of a robust dead beat control system considered a transient response

  • Yoshida, Satoru;Kamiya, Yuji
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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    • pp.106-109
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    • 1995
  • First, in this paper we propose a new dead best control system design technique by which we can specify a transient response before the settling time. Though the resultant system has the same system configuration as Reference[1], that is realized by adapting the performance index which includes the term of the square of difference between specified and pracitical responses. Next, we state a technique which gives the dead beat control system robustness and construct a robust dead beat control system. Simulations of the proposed dead beat control and robust dead beat control systems show expected results.

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A Study for Robustness of Objective Function and Constraints in Robust Design Optimization

  • Lee Tae-Won
    • Journal of Mechanical Science and Technology
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    • 제20권10호
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    • pp.1662-1669
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    • 2006
  • Since randomness and uncertainties of design parameters are inherent, the robust design has gained an ever increasing importance in mechanical engineering. The robustness is assessed by the measure of performance variability around mean value, which is called as standard deviation. Hence, constraints in robust optimization problem can be approached as probability constraints in reliability based optimization. Then, the FOSM (first order second moment) method or the AFOSM (advanced first order second moment) method can be used to calculate the mean values and the standard deviations of functions describing constraints and object. Among two methods, AFOSM method has some advantage over FOSM method in evaluation of probability. Nevertheless, it is difficult to obtain the mean value and the standard deviation of objective function using AFOSM method, because it requires that the mean value of function is always positive. This paper presented a special technique to overcome this weakness of AFOSM method. The mean value and the standard deviation of objective function by the proposed method are reliable as shown in examples compared with results by FOSM method.

입력관측기의 정량적 성능지표 (I) -과도상태 해석- (A Quantitative Performance Input for an Input Observer ( I ) - Analysis in Transient State -)

  • 정종철;이범석;허건수
    • 대한기계학회논문집A
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    • 제26권10호
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    • pp.2060-2066
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    • 2002
  • The closed-loop state and input observer is a pole-placement type observer and estimates unknown state and input variables simultaneously. Pole-placement type observers may have poor transient performance with respect to ill-conditioning factors such as unknown initial estimates, round-off error, etc. For the robust transient performance, the effects of these ill-conditioning factors must be minimized in designing observers. In this paper, the transient performance of the closed-loop state and input observer is investigated quantitatively by considering the error bounds due to ill-conditioning factors. The performance indices are selected from these error bounds and are related to the observer robustness with respect to the ill -conditioning factors. The closed-loop state and input observer with small performance indices is considered as a well-conditioned observer from the transient perspective.

성능지표 선정을 통한 강인한 칼만필터 설계 (Robust Kalman Filter Design via Selecting Performance Indices)

  • 정종철;허건수
    • 대한기계학회논문집A
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    • 제29권1호
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    • pp.59-66
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    • 2005
  • In this paper, a robust stationary Kalman filter is designed by minimizing selected performance indices so that it is less sensitive to uncertainties. The uncertainties include not only stochastic factors such as process noise and measurement noise, but also deterministic factors such as unknown initial estimation error, modeling error and sensing bias. To reduce the effect on the uncertainties, three performance indices that should be minimized are selected based on the quantitative error analysis to both the deterministic and the stochastic uncertainties. The selected indices are the size of the observer gain, the condition number of the observer matrix, and the estimation error variance. The observer gain is obtained by optimally solving the multi-objectives optimization problem that minimizes the indices. The robustness of the proposed filter is demonstrated through the comparison with the standard Kalman filter.