• 제목/요약/키워드: M-systems

검색결과 8,895건 처리시간 0.049초

Energy Reduction in LCD Displays

  • Liu, Tao;O'Neill, Mark;Hoffman, Kevin M.;Sanford, Quinn D.;Serres, Alan M.;Schiller, Robert
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.780-783
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    • 2008
  • Low-loss optical films can be used in LCD backlights to improve the display efficiency. Improvements can be used to enhance display performance, increase functionality and reduce energy costs.

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A Survey on Security Issues of M2M Communications in Cyber-Physical Systems

  • Chen, Dong;Chang, Guiran
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제6권1호
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    • pp.24-45
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    • 2012
  • In this paper, we present a survey of security and privacy preserving issues in M2M communications in Cyber-Physical Systems. First, we discuss the security challenges in M2M communications in wireless networks of Cyber-Physical Systems and outline the constraints, attack issues, and a set of challenges that need to be addressed for building secure Cyber-Physical Systems. Then, a secure architecture suitable for Cyber-Physical Systems is proposed to cope with these security issues. Eventually, the corresponding countermeasures to the security issues are discussed from four aspects: access control, intrusion detection, authentication and privacy preserving, respectively. Along the way we highlight the advantages and disadvantages of various existing security schemes and further compare and evaluate these schemes from each of these four aspects. We also point out the open research issues in each subarea and conclude with possible future research directions on security in Cyber-Physical Systems. It is believed that once these challenges are surmounted, applications with intrinsic security considerations will become immediately realizable.

위탁급식업체 정보시스템 사용자 만족도에 관한 연구 (A Study of User Satisfaction of Contract Foodservice Information Systems)

  • 최성경
    • 한국식품영양학회지
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    • 제15권3호
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    • pp.250-256
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    • 2002
  • User satisfaction is the most critical criteria in measuring information systems success or failure. In this study, Contract Foodservice Information Systems were evaluated with user satisfaction instrument based on previous work. A total of 70 Contract Foodservice Information Systems users was surveyed. The status of building area of Contract Foodservice Information Systems was more in foodservice management (M=3.74), but less in producing (M=2.53) and pruchasing (M=3.02) management. The users recognized .accuracy of information (M=4.27), lasting educational services on systems (M=4.34) and increasing work productivity (M=4.42) as the most important factors and they also recognized it was important factors to build systems such area database management, menu management, purchasing and producing management and foodservice management (p<.01.).

A Method for Separating Volterra Kernels of Nonlinear Systems by Use of Different Amplitude M-sequences

  • Harada, Hiroshi;Nishiyama, Eiji;Kashiwagi, Hiroshi;Yamaguchi, Teruo
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1998년도 제13차 학술회의논문집
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    • pp.271-274
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    • 1998
  • This paper describes a new method for separation of the Volterra kernels which are identified by use of M-sequence. One of the authors has proposed a method for identification of Volterra kernels of nonlinear systems using M-sequence and correlation technique. When M-sequence are applied to a nonlinear systems, the cross-correlation function between the input and the output of the nonlinear systems includes cross-sections of high-order Volterra kernels. However, if various order Volterra kernels exixt on the obtained cross-correlation function, it is difficult to separate the Volterra kernels. In this paper, the authors show that the magnitude of Volterra kernels is maginified by the amplitude of M-sequence according to the order of Volterra kernels. By use of this property, each order Volterra kernels is obtained by solving linear equations. Simulations are carried out for some nonlinear systems. The results show that Volterra kernels can be separated in each order successfully by the proposed method.

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Asymptotic Distributions of Maximum Queue Lengths for M/G/1 and GI/M/i Systems

  • Park, You-Sung
    • Journal of the Korean Statistical Society
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    • 제24권1호
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    • pp.19-29
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    • 1995
  • In this paper, we investigate the asymptotic distributions of maximum queue length for M/G/1 and GI/M/1 systems which are positive recurrent. It is well knwon that for any positive recurrent queueing systems, the distributions of their maxima linearly normalized do not have non-degenerate limits. We show, however, that by concerning an array of queueing processes limiting behaviors of these maximum queue lengths can be established under certain conditions.

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ON DIFFERENTIAL INVARIANTS OF HYPERPLANE SYSTEMS ON NONDEGENERATE EQUIVARIANT EMBEDDINGS OF HOMOGENEOUS SPACES

  • HONG, JAEHYUN
    • 대한수학회논문집
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    • 제30권3호
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    • pp.253-267
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    • 2015
  • Given a complex submanifoldM of the projective space $\mathbb{P}$(T), the hyperplane system R on M characterizes the projective embedding of M into $\mathbb{P}$(T) in the following sense: for any two nondegenerate complex submanifolds $M{\subset}\mathbb{P}$(T) and $M^{\prime}{\subset}\mathbb{P}$(T'), there is a projective linear transformation that sends an open subset of M onto an open subset of M' if and only if (M,R) is locally equivalent to (M', R'). Se-ashi developed a theory for the differential invariants of these types of systems of linear differential equations. In particular, the theory applies to systems of linear differential equations that have symbols equivalent to the hyperplane systems on nondegenerate equivariant embeddings of compact Hermitian symmetric spaces. In this paper, we extend this result to hyperplane systems on nondegenerate equivariant embeddings of homogeneous spaces of the first kind.

무기체계 획득을 위한 모델링 및 시뮬레이션(M&S) 활용에 관한 연구 (A Study on Weapon Systems Acquisition for the Use of Modeling & Simulation(M&S))

  • 이필중;이영욱
    • 융합보안논문지
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    • 제11권3호
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    • pp.11-17
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    • 2011
  • 무기체계의 획득은 획득과정 초기단계에서 시험평가 자료의 원천으로 모델링 및 시뮬레이션의 사용이 적극적으로 권장되고 있다. 이와 같이 무기체계의 획득에 있어서 신뢰성은 가장 중요한 부분 이라할 수 있고, 이를 위해 M&S를 적용하여 시험평가의 신뢰성과 정확성을 제공할 수 있으며, 시험에 소요되는 시간과 비용의 절감, 사전 예측 및 사후 검증등이 가능한 자료를 제공할 수 있다. 따라서 본 연구에서는 M&S의 이론적인 고찰과 무기체계의 획득을 위한 M&S 활용의 중요성, 획득모델의 특징, 무기체계 획득을 위한 활용실태 등을 고찰하여 효과적인 무기체계 획득을 위한 M&S의 활용방안을 찾고자 한다.

동일 상관 신호군을 이용하는 M-ary UWB 다원 접속 시스템에서 PN 부호 기반 시간 도약 시퀀스의 성능 (Performance of PN Code Based Time Hopping Sequences in M-ary Ultra Wide Band Multiple Access Systems Using Equicorrelated Signal Sets)

  • 양석철;신요안
    • 한국통신학회논문지
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    • 제28권10A호
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    • pp.816-829
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    • 2003
  • 본 논문에서는 동일 상관 신호군을 이용하는 M-ary UWB (Ultra Wide Band) 다원 접속 시스템에서 PN(Pseudo Noise) 부호 기반의 시간 도약 시퀀스를 이용하는 경우의 성능을 평가하였다. 특히 심벌 수 M이 증가해도 신호 펄스열의 길이가 변화하지 않아 M에 관계없이 동일 심벌 전송률을 갖게 되는 M-ary UWB 시스템 (시스템 #1)과 신호 펄스열의 길이가 M의 증가에 따라 확장되어 M이 증가하여도 동일 비트 전송률을 갖게 되는 M-ary UWB 시스템 (시스템 #2)을 모두 고려하여, UWB 실내 무선 다중 경로 채널 하에서의 심벌오율 성능을 이상적인 랜덤 시간 도약 시퀀스를 적용한 다원 접속 시스템의 성능과 비교 분석하였다. 모의 실험 결과, PN 부호 기반의 시간 도약 시퀀스가 이상적인 랜덤 시퀀스와 거의 유사한 매우 우수한 성능을 나타냄을 알 수 있었다. 또한, 심벌수가 증가함에 따라 시스템 #2의 경우가 시스템 #1의 경우보다 다원 접속 간섭에 대한 강인성 측면에 있어서 월등히 우수함을 확인하였다.