• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.314-314
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• 1996

We investigate the scheduling problem for periodic job shops with blocking. We develop Petri net models for periodic job shops with finite buffers. A buffer control method would allow the jobs to enter the input buffer of the next machine in the order for which they are completed. We discuss difficulties in using such a random order buffer control method and random access buffers. We thus propose an alternative buffer control policy that restricts the jobs to enter the input buffer of the next machine in a predetermined order. The buffer control method simplifies job flows and control systems. Further, it requires only a cost-effective simple sequential buffer. We show that the periodic scheduling model with finite buffers using the buffer control policy can be transformed into an equivalent periodic scheduling model with no buffer, which is modeled as a timed marked graph. We characterize the structural properties for deadlock detection. Finally, we develop a mixed integer programming model for the no buffer problem that finds a deadlock-free optimal sequence that minimizes the cycle time.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.406-410
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• 1990

This paper presents an approximate analysis of the serial production lines using decomposition technique. A serial production line consists of a series of unreliable machines separated by finite buffers. The serial production line is evaluated by approximation method, the results of which are compared with those examined by the discrete time event simulation, based on this approximation method, a gradient technique is proposed, which improves the efficiency of an operation of production line through the re-allocation of buffers.

• Journal of Korean Institute of Industrial Engineers
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• v.23 no.4
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• pp.769-778
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• 1997

Assembly/Disassembly Queueing Networks (ADQNs) with finite buffers have been used as a major tool for evaluating the performances of manufacturing and parallel processing systems. In this study, we present simple but effective methods which yield throughput upper and lower bounds for ADQNs with exponential service times and finite buffers. These methods are based on the monotonicity properties of throughputs with respect to service times and buffer capacities. The throughput-upper bounding method is elaborated on with general network configuration (specifically acyclic configuration). But our lower bounding method is restricted to the ADQNs with more specialized configuration. Computational experiments will be performed to confirm the effectiveness of our throughput-bounding methods.

• Industrial Engineering and Management Systems
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• v.12 no.3
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• pp.274-280
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• 2013

This paper proposes a space merging approach to studying the queuing models with finite buffers and jump priorities. Upon the arrival of a call with low priority, one call of such kind is assumed to be transferred to the end of the queue of high priority calls. The transfer probabilities depend on the state of the queue of the heterogeneous calls. We developed the algorithms to calculate the quality of service metrics of such queuing models, and the results of the numerical experiments are shown.

• Journal of IKEEE
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• v.19 no.1
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• pp.10-17
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• 2015

In this Paper, an efficient method of FPGA based design and implementation of Sobel Edge detector block using 3-Line buffers is presented. The FPGA provides the proper and sufficient hardware for image processing algorithms with flexibility to support Sobel edge detection algorithm. A pipe-lined method is used to implement the edge detector. The proposed Sobel edge detection operator is an model using of Finite State Machine(FSM) which executes a matrix mask operation to determine the level of edge intensity through different of pixels on an image. This approach is useful to improve the system performance by taking advantage of efficient look up tables, flip-flop resources on target device. The proposed Sobel detector using 3-line buffers is synthesized with Xilinx ISE 14.2 and implemented on Virtex II xc2vp-30-7-FF896 FPGA device. Using matlab, we show better PSNR performance of proposed design in terms of 3-Line buffers utilization.

• East Asian mathematical journal
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• v.24 no.4
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• pp.407-414
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• 2008

Finite difference schemes are considered for a $Ca^{2+}$ diffusion equations with damping and convection terms, which describe $Ca^{2+}$ buffering by using stationary and mobile buffers. Stability and $L^{\infty}$ error estimates of approximate solutions for the corresponding schemes are obtained using the extended Lax-Richtmyer equivalence theorem.

• Journal of applied mathematics & informatics
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• v.27 no.5_6
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• pp.1247-1256
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• 2009

Finite difference schemes are considered for a nonlinear $Ca^{2+}$ diffusion equations with stationary and mobile buffers. The scheme inherits mass conservation as for the classical solution. Stability and $L^{\infty}$ error estimates of approximate solutions for the corresponding schemes are obtained. using the extended Lax-Richtmyer equivalence theorem.

• Journal of the Korea Society for Simulation
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• v.19 no.3
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• pp.109-117
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• 2010

In this study, we consider stationary waiting times in a simple fork-and-join type queue which consists of three single-server machines, Machine 1, Machine 2, and Assembly Machine. We assume that the queue has a renewal arrival process and that independent service times at each node are either deterministic or non-overlapping. We also assume that the Machines 1 and 2 have an infinite buffer capacity whereas the Assembly Machine has two finite buffers, one for each machine. Services at each machine are given by FIFO service discipline and a communication blocking policy. We derive the explicit expressions for stationary waiting times at all nodes as a function of finite buffer capacities by using (max,+)-algebra. Various characteristics of stationary waiting times such as mean, higher moments, and tail probability can be computed from these expressions.

• Journal of the Korean Operations Research and Management Science Society
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• v.30 no.1
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• pp.149-159
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• 2005

In this study, we consider characteristics of stationary waiting times in single-server 2-node tandem queues with a finite buffer, a Poisson arrival process and deterministic service times. The system has two buffers: one at the first node is infinite and the other one at the second node is finite. We show that the sojourn time or departure process does not depend on the capacity of the finite buffer and on the order of nodes (service times), which are the same as the previous results. Furthermore, the explicit expressions of waiting times at the first node are given as a function of the capacity of the finite buffer and we are able to disclose a relationship of waiting times between under communication blocking and under manufacturing blocking. Some numerical examples are also given.

• Korean Management Science Review
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• v.24 no.1
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• pp.25-34
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• 2007

In this study, we consider stationary waiting times in finite-buffer 3-node single-server queues in series with a Poisson arrival process and with either constant or non-overlapping service times. We assume that each node has a finite buffer except for the first node. The explicit expressions of waiting times in all areas of the stochastic system were driven as functions of finite buffer capacities. These explicit forms show that a system sojourn time does not depend on the finite buffer sizes, and also allow one to compute and compare characteristics of stationary waiting times at all areas under two blocking rules communication and manufacturing blocking. The goal of this study is to apply these results to an optimization problem which determines the smallest buffer capacities satisfying predetermined probabilistic constraints on stationary waiting times at all nodes. Numerical examples are also provided.