• Title/Summary/Keyword: Mixed Functions

검색결과 446건 처리시간 0.022초

소프트웨어 신뢰모형에 대한 베이지안 접근 (Bayesian Approach for Software Reliability Models)

  • 최기헌
    • Journal of the Korean Data and Information Science Society
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    • 제10권1호
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    • pp.119-133
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    • 1999
  • 마코브체인 몬테칼로 방법을 소프트웨어 신뢰모형에 이용하였다. 베이지안 추론에서 조건부 분포를 가지고 사후분포를 결정하는데 있어서의 계산 문제를 고찰하였다. 특히 레코드값을 통계량을 갖고서 혼합과정과 중첩과정에 대하여 깁스샘플링 알고리즘과 메트로폴리스 알고리즘을 활용하여 베이지안 계산과 모형 선택을 제시하고 모의실험자료를 이용하여 수치적 인 계산을 시행하고 그 결과를 비교하였다.

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Membership Function-based Classification Algorithms for Stability improvements of BCI Systems

  • Yeom, Hong-Gi;Sim, Kwee-Bo
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제10권1호
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    • pp.59-64
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    • 2010
  • To improve system performance, we apply the concept of membership function to Variance Considered Machines (VCMs) which is a modified algorithm of Support Vector Machines (SVMs) proposed in our previous studies. Many classification algorithms separate nonlinear data well. However, existing algorithms have ignored the fact that probabilities of error are very high in the data-mixed area. Therefore, we make our algorithm ignore data which has high error probabilities and consider data importantly which has low error probabilities to generate system output according to the probabilities of error. To get membership function, we calculate sigmoid function from the dataset by considering means and variances. After computation, this membership function is applied to the VCMs.

부하(負荷) 판별(判別)을 위한 Wavelet 변환(變煥)의 응용에 관한 연구 (A Study on Application of Wavelet Transform to Electrical Load Discriminations)

  • 김태홍;이상수;성상규;이기영;지석준;이준탁
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 D
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    • pp.3050-3052
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    • 2000
  • Recently. the subject of "wavelet analysis" has drawn much attention from both mathematical and engineering application fields such as Signal Processing, Compression/ Decomposition, Statistics and etc. Analogous to Fourier analysis, wavelets is a versatile tool with very rich mathematical content and great potential for applications. Specially, wavelet transform uses localizable various mother wavelet functions in time-frequency domain. In this paper, discrimination analyses of acquired electrical current signals for each and mixed loads were tried by using Morlet wavelet transform. Their representative loads were classified as TV, DRY, REF, and FL.

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Dynamic behaviour of stiffened and damaged coupled shear walls

  • Meftah, S.A.;Tounsi, A.;Adda-Bedia, E.A.
    • Computers and Concrete
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    • 제3권5호
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    • pp.285-299
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    • 2006
  • The free vibration of stiffened and damaged coupled shear walls is investigated using the mixed finite element method. The anisotropic damage model is adopted to describe the damage extent of the reinforced concrete shear wall element. The internal energy of a locally damaged shear wall element is derived. Polynomial shape functions established by Kwan are used to present the component of displacements vector on each point within the wall element. The principle of virtual work is employed to deduce the stiffness matrix of a damaged shear wall element. The stiffened system is reinforced by an additional stiffening beam at some level of the structure. This induces additional axial forces, and thus reduces the bending moments in the walls and the lateral deflection, and increases the natural frequencies. The effects of the damage extent and the stiffening beam on the free vibration characteristics of the structure are studied. The optimal location of the stiffening beam for increasing as far as possible the first natural frequency of vibration is presented.

우반구 손상 환자의 한글 실서증 특징 (Korean Agraphia Subsequent to Right Hemispheric Lesion)

  • 윤지혜;신지철;김덕용;서미경;김향희
    • 음성과학
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    • 제13권3호
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    • pp.121-132
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    • 2006
  • In Hangeul, the graphemes of syllables are organized in horizontal, vertical and mixed (both horizontal & vertical) orientations, and the graphemic position of consonant(s) and vowel(s) within a each syllable needs to be maintained within a square pattern. We investigated the characteristics of writing errors of 9 stroke patients with right hemisphere (RH) lesions and compared it to the performances of 15 normal subjects. The subjects were asked to write to dictation of 90 Korean syllables. One of the interesting findings was that our patients manifested visuospatial errors which are not commonly observed in other language-speaking (e.g., English) patients due to the unique syllabic organizations of Korean writing system. The prominent errors in the RH group could be explained by the impaired RH which normally controls the visuospatial functions.

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Effect of the multilayer structure on electrical and mechanical properties fo thin film yttria stabilized zirconia electrolyte

  • Jung, In-Ho;Lee, You-Kee;Park, Jong-Wan
    • Journal of Korean Vacuum Science & Technology
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    • 제2권1호
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    • pp.43-48
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    • 1998
  • The effect of mcirostructure on the electrical properties of yttria stabilized zirconia (YSZ) was analyzed by modeling layer arrangements and mixed phase structure. The YSZ thin films were deposited by RF magnetron sputtering using 30mol% YSZ and 8 mol% YSZ targets with yttrium pellets on porous alumina substrates. The structure, composition and electricla properties of the YSZ films were investigated as functions of sputtering conditons and layer arrangements by XRD, TEM, XPS and acimpedance spectroscopy. The results showed that the triple palyered YSZ films had highermicrohardness, lower compressive stress state and higher ionic conductivity by one order than single and double layered YSZ films. However, sputtered YSZ films have low conductivity compared to YSZ pellets or doctor bladed YSZ thin plates. These results were probably due to the influence of insulating alumina substrates, impractical for most stacking geometries and inductance induced by relatively long platinum, lead wire on YSZ conductivity.

Game Theory-based Bi-Level Pricing Scheme for Smart Grid Scheduling Control Algorithm

  • Park, Youngjae;Kim, Sungwook
    • Journal of Communications and Networks
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    • 제18권3호
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    • pp.484-492
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    • 2016
  • Smart grid (SG) technology is now elevating the conventional power grid system to one that functions more cooperatively, responsively, and economically. When applied in an SG the demand side management (DSM) technique can improve its reliability by dynamically changing electricity consumption or rescheduling it. In this paper, we propose a new SG scheduling scheme that uses the DSM technique. To achieve effective SG management, we adopt a mixed pricing strategy based on the Rubinstein-Stahl bargaining game and a repeated game model. The proposed game-based pricing strategy provides energy routing for effective energy sharing and allows consumers to make informed decisions regarding their power consumption. Our approach can encourage consumers to schedule their power consumption profiles independently while minimizing their payment and the peak-to-average ratio (PAR). Through a simulation study, it is demonstrated that the proposed scheme can obtain a better performance than other existing schemes in terms of power consumption, price, average payment, etc.

옥상 녹화지의 시각적 선호도 (Visual Preference in Green Roof Sites)

  • 이관규
    • 한국조경학회지
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    • 제34권5호
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    • pp.32-38
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    • 2006
  • Roof greening in a city can contributes to not only providing network opportunities for dispersed greenspace patches but also bringing more greenspaces into a city. In addition, it can help to flooding and microclimate control in the city. Recently, a number of roof greening projects have been introduced, mainly to public buildings and schools. Roof peening need to offers both ecological functions and convenience and satisfaction for urban residents. This study aims to provide directions for improving ecological benefits and visual preference of roof greening. Twelve scene slides were adopted to measure people's visual preference. The survey results show that landscape images can be categorized into naturalness, visual diversity, uniqueness, and spatial flexibility. Physical scenes can be classified into type I mostly greened by plants, type II mixed between convenience facilities and plants, and type III constructed with pond. People show high preferences to type I and type II when visual diversity is high. The results of this study suggest to enhance the visual preference by considering visual diversity when applying the ecological design methods to improve naturalness for roof greening.

Symbiotic Organisms Search for Constrained Optimization Problems

  • Wang, Yanjiao;Tao, Huanhuan;Ma, Zhuang
    • Journal of Information Processing Systems
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    • 제16권1호
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    • pp.210-223
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    • 2020
  • Since constrained optimization algorithms are easy to fall into local optimum and their ability of searching are weak, an improved symbiotic organisms search algorithm with mixed strategy based on adaptive ε constrained (ε_SOSMS) is proposed in this paper. Firstly, an adaptive ε constrained method is presented to balance the relationship between the constrained violation degrees and fitness. Secondly, the evolutionary strategies of symbiotic organisms search algorithm are improved as follows. Selecting different best individuals according to the proportion of feasible individuals and infeasible individuals to make evolutionary strategy more suitable for solving constrained optimization problems, and the individual comparison criteria is replaced with population selection strategy, which can better enhance the diversity of population. Finally, numerical experiments on 13 benchmark functions show that not only is ε_SOSMS able to converge to the global optimal solution, but also it has better robustness.

강인한 궤환 능동 소음 제어기의 설계에 관한 연구 (A Study on the Design of the Robust Feedback Active Noise Controller)

  • 안우현;정태진;유치형;정찬수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 하계학술대회 논문집 B
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    • pp.1018-1020
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    • 1996
  • In this paper, when a robust active noise controller for a small cavity to control the noise induced in the cavity is designed, the Graphical method based on the robust stability and performance requirements is studied. The problem of designing controller that achieve these robust performance conditions is related to minimizing the $H_{\infty}$ norm of the mixed sensitivity function by using $H_{\infty}$ control theory. Also, For design the controller, the loopshaping method which control the weight functions to satisfy the design specification without loss of a robust performance can be used. Therefore, we determined the acceptable design specification with the system characteristics of the small cavity and obtained its robust controller with the robust performance specifications by stability margin.

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