• Title/Summary/Keyword: Discrete time

Search Result 2,374, Processing Time 0.027 seconds

DISCRETE-TIME $Geo^X/G/l$ QUEUE WITH PLACE RESERVATION DISCIPLINE

  • Lee Yu-Tae
    • Journal of applied mathematics & informatics
    • /
    • v.22 no.1_2
    • /
    • pp.453-460
    • /
    • 2006
  • A discrete-time priority queueing system with place reservation discipline is studied, in which two different types of packets arrive according to batch geometric streams. It is assumed that there is a reserved place in the queue. Whenever a high-priority packet enters the queue, it will seize the reserved place and make a new reservation at the end of the queue. Low-priority arrivals take place at the end of the queue in the usual way. Using the probability generating function method, the joint distribution of system state and the delay distribution for each type are obtained.

Robust H$_\infty$ Control for Discrete Time-delay Linear Systems with Frobenius Norm-bounded Uncertainties (파라미터 불확실성을 가지는 이산 시간지연 시스템에 대한 견실 H$_\infty$ 제어)

  • 김기태;이형호;이상경;박홍배
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2000.10a
    • /
    • pp.23-23
    • /
    • 2000
  • In this paper, we proposed the problems of robust stability and 개bust H$_{\infty}$ control of discrete time-delay linear st.stems with Frobenius norm-bounded uncertainties. The existence condition and the design method of robust H$_{\infty}$ state feedback control]or are given. Through some changes of variables and Schur complement, the obtained sufficient condition can be rewritten as an LMI(linear matrix inequality) form in terms of all variables.

  • PDF

Design of Minimum Variance Fault Diagnosis Filter for Linear Discrete-Time Stochastic Systems with Unknown Inputs (미지입력이 존재하는 선형 이산 활률 시스템의 최소 분산 고장 진단 필터의 설계)

  • ;Zeungnam Bien
    • Journal of the Korean Institute of Telematics and Electronics B
    • /
    • v.31B no.8
    • /
    • pp.39-46
    • /
    • 1994
  • In this paper a state reconstruction filter for linear discrete-time stochastic systems with unknown inputs and noises is presented. The suggested filter can estimate the system state vector and the unknown inputs simultaneously As an extension of the filter a fault diagnosis filter for linear discrete-time stochastic systems with unknown inputs and noises is presented for each filters the optimal gain determination methods which minimize the variance of the state reconstruction errorare presented. Finally the usability of the filtersis shown via numerical examples.

  • PDF

A Robust Discrete-Time Adaptive Control with a Compensator (보상기를 이용한 강인한 이산 시간 적응 제어)

  • 이호진;최계근
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.25 no.12
    • /
    • pp.1610-1617
    • /
    • 1988
  • In this paper, a robust discrete-time adaptive control with compensation is proposed for single-input single-output discrete-time plants which have unmodeled dynamics. The stability of the overall system is studied using the conic sector stability theorems when a normalized constant gain parameter adaptation algorithm and a properly chosen compensation are used. An illustrative exmple shows that this compensation can also increase the parameter adaptation speed. And a method of compensation using the adaptive observation is also discussed.

  • PDF

A performance analysis of the discrete time DS/CDMA system based on the code phase difference (코드 위상차에 따른 이산 시간 CDMA 시스템의 성능 분석)

  • 안병양
    • Journal of the Korean Institute of Telematics and Electronics S
    • /
    • v.35S no.5
    • /
    • pp.11-16
    • /
    • 1998
  • DS/CDMA systems for the high speed communication require high code rats. In discrete time CDMA receivers, the performance degradation, caused by the phase difference between transmission code and reference code, increase the sampling frquency of the receiver. This increment of the sampling frequency makes hard to implement high speed CDMA systems. This paper analyzes the SIR(signal to interference Ratio) performance of the discrete time DS/CDMA system, based on the code phase difference. The results of this paper may be useful to study a low-sampling CDMA receiver.

  • PDF

Small Signal Modeling for the PWM Series Resonant Converter (PWM-SRC) (펄스-폭 변조방식의 직렬공진 컨버터의 소신호 모델링)

  • Choi, Hyun-Chil
    • The Transactions of the Korean Institute of Electrical Engineers A
    • /
    • v.48 no.11
    • /
    • pp.1441-1447
    • /
    • 1999
  • A discrete time domain modeling is presented for the pulse-width modulated series resonant converter (PWM-SRC) with a discontinuous current mode. This nonlinear system is linearized about its equilibrium state to obtain a linear discrete time model for the investigation of small signal performances such as the stability and transient response. The usefulness of this small signal model is verified through the dynamic simulation.

  • PDF

Waiting Time Analysis of Discrete-Time BMAP/G/1 Queue Under D-policy (D-정책을 갖는 이산시간 BMAP/G/1 대기행렬의 대기시간 분석)

  • Lee, Se Won
    • Journal of Korea Society of Industrial Information Systems
    • /
    • v.23 no.1
    • /
    • pp.53-63
    • /
    • 2018
  • In this paper, we analyze the waiting time of a queueing system with D-BMAP (discrete-time batch Markovian arrival process) and D-policy. Customer group or packets arrives at the system according to discrete-time Markovian arrival process, and an idle single server becomes busy when the total service time of waiting customer group exceeds the predetermined workload threshold D. Once the server starts busy period, the server provides service until there is no customer in the system. The steady-state waiting time distribution is derived in the form of a generating function. Mean waiting time is derived as a performance measure. Simulation is also performed for the purpose of verification and validation. Two simple numerical examples are shown.

Stability Bound for Time-Varying Uncertainty of Positive Time-Varying Discrete Systems with Time-Varying Delay Time (시변 지연시간을 갖는 양의 시변 이산시스템의 시변 불확실성의 안정범위)

  • Han, Hyung-Seok
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.22 no.6
    • /
    • pp.424-428
    • /
    • 2016
  • A simple new sufficient condition for asymptotic stability of the positive linear time-varying discrete-time systems, with unstructured time-varying uncertainty in delayed states, is established in this paper Compared with previous results that cannot be applied to time-varying systems; the time-varying system and delay time are considered simultaneously in this paper. The proposed conditions are compared with suitable conditions for the typical discrete-time systems. The considerations are illustrated by numerical examples of previous work.

Logical Analysis of Real-time Discrete Event Control Systems Using Communicating DEVS Formalism (C-DEVS형식론을 이용한 실시간 이산사건 제어시스템의 논리 해석 기법)

  • Song, Hae Sang;Kim, Tag Gon
    • Journal of the Korea Society for Simulation
    • /
    • v.21 no.4
    • /
    • pp.35-46
    • /
    • 2012
  • As complexity of real-time systems is being increased ad hoc approaches to analysis of such systems would have limitations in completeness and coverability for states space search. Formal means using a model-based approach would solve such limitations. This paper proposes a model-based formal method for logical analysis, such as safety and liveness, of real-time systems at a discrete event system level. A discrete event model for real-time systems to be analyzed is specified by DEVS(Discrete Event Systems Specification) formalism, which specifies a discrete event system in hierarchical, modular manner. Analysis of such DEVS models is performed by Communicating DEVS (C-DEVS) formalism of a timed global state transition specification and an associated analysis algorithm. The C-DEVS formalism and an associated analysis algorithm guarantees that all possible states for a given system are visited in an analysis phase. A case study of a safety analysis for a rail road crossing system illustrates the effectiveness of the proposed method of the model-based approach.

Discrete Event Simulation for the Initial Capacity Estimation of Shipyard Based on the Master Production Schedule (대일정 생산 계획에 따른 조선소 생산 용량의 초기 평가를 위한 이산사건 시뮬레이션)

  • Kim, Kwang-Sik;Hwang, Ho-Jin;Lee, Jang-Hyun
    • Korean Journal of Computational Design and Engineering
    • /
    • v.17 no.2
    • /
    • pp.111-122
    • /
    • 2012
  • Capacity planning plays an important role not only for master production plan but also for facility or layout design in shipbuilding. Product work breakdown structure, attributes of production resources, and production method or process data are associated in order to make the discrete event simulation model of shipyard layout plan. The production amount of each process and the process time is assumed to be stochastic. Based on the stochastic discrete event simulation model, the production capacity of each facility in shipyard is estimated. The stochastic model of product arrival time, process time and transferring time is introduced for each process. Also, the production capacity is estimated for the assumed master production schedule.