• IE interfaces
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• v.15 no.3
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• pp.316-324
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• 2002

Automated Guided Vehicles are widely used as an essential material handling system for FMS to provide flexibility and efficiency. We suggest a new dispatching rule based on priority function which considers urgency and empty vehicle travel time under finite buffer capacity. We evaluate the performance of the proposed rule by comparing the performance of Shortest Travel Time/Distance(STT/D) rule in terms of machine utilization, throughput and WIP level using simulation. The simulation results show that the suggested dispatching rule is robust and provides better machine utilization, throughput with comparable WIP level compared to STT/D rule.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.9B
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• pp.783-792
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• 2003

We consider a finite-buffer discrete-time queueing system with fixed-size bulk-service discipline: Geo/ $G^{B}$1/K＋B. The main purpose of this paper is to present a performance analysis of this system that has a wide range of applications in Asynchronous Transfer Mode (ATM) and other related telecommunication systems. For this purpose, we first derive the departure-epoch probabilities based on the embedded Markov chain method. Next, based on simple rate in and rate out argument, we present stable relationships for the steady-state probabilities of the queue length at different epochs: departure, random, and arrival. Finally, based on these relationships, we present various useful performance measures of interest such as the moments of number of packets in the system at three different epochs and the loss probability. The numerical results are presented for a deterministic service-time distribution - a case that has gained importance in recent years.s.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.8
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• pp.1159-1168
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• 1993

The Switched-Capacitor Integrator(SCI) is a basic building block of Switched-Scpacitor Filter(SCF). But owing to the errors from the finite gain and bandwidth of op-amp on SCI, the most of SCP are limited to their applications. Although many of the compensation methods developed for active RC filters can be directly adapted to SCF, this is not true for the analysis of the effects of the op-amp dynamics on the filter response. The effect of finite op-amp gain is similar to the active RC filters. But SCF is more toter-ant of the finite op-amp bandwidth. In this paper, we have considered the errors of the finite gain and bandwidth of op-amp on SCI , and presented the simple and effective methods of compensating the errors of SCI due to the finite op-amp gain using the buffer circuit.

• Journal of applied mathematics & informatics
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• v.33 no.1_2
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• pp.185-191
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• 2015

This paper considers a discrete-time buffer system with session-based arrivals, an infinite storage capacity and one unreliable output line. There are multiple different types of sessions and the output line is governed by a finite state Markov chain. Based on a generating functions approach, we obtain an exact expression for the mean buffer content.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.2
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• pp.1-7
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• 1996

In this paper, we analyzed the packet blocking probability of a finite buffer in a network interface unit. In general, a network interface unit which provides a means of interface between the network and computer has a microprocessor and a protocol processor for the network access protocols. It also has a receive buffer for the arriving packets from the network which is served by the microprocessor with service interruption by the protocol processor. In this paper, we modeled the receive buffer as a discrete time server with service interruption, and obtained the packet blocking probability using the mini-slot approximation.

• Journal of the Korean Mathematical Society
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• v.40 no.1
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• pp.87-107
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• 2003

In this paper, we consider a discrete time queueing system fed by a superposition of an ON and OFF source with heavy tail ON periods and geometric OFF periods and a D-BMAP (Discrete Batch Markovian Arrival Process). We study the tail behavior of the queue length distribution and both infinite and finite buffer systems are considered. In the infinite buffer case, we show that the asymptotic tail behavior of the queue length of the system is equivalent to that of the same queueing system with the D-BMAP being replaced by a batch renewal process. In the finite buffer case (of buffer size K), we derive upper and lower bounds of the asymptotic behavior of the loss probability as $K\;\longrightarrow\;\infty$.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.407-410
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• 1997

This paper analytically derives the variance of service time of a station in the symmetric IEEE 802.4 token bus network with single access class and finite buffer capacity. This performance measure is represented in terms of the total number of stations, the token hold time, the arrival rate of frames, the service rate, and other parameters. Using computer simulations, presented performance measure is validated.

• Journal of the Korean Operations Research and Management Science Society
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• v.30 no.2
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• pp.131-142
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• 2005

This paper proposes queueing models for a Web server system which is composed of an infinite-buffer main server and finite-buffer auxiliary server(s). The system is modeled by the level-dependent quasi-birth- death (QBD) process. Utilizing the special structure of the QBD, we convert the infinite level-dependent QBD into a finite level-independent QBD and compute the state probabilities. We then explore the operational characteristics of the proposed web-server models and draw some useful conclusions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.11
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• pp.5271-5289
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• 2016

On large-scale data analysis platforms deployed on cloud infrastructures over the Internet, the instability of the data transfer time and the dynamics of the processing rate require a more sophisticated data distribution scheme which maximizes parallel efficiency by achieving the balanced load among participated computing elements and by eliminating the idle time of each computing element. In particular, under the constraints that have the real-time and limited data buffer (in-memory storage) are given, it needs more controllable mechanism to prevent both the overflow and the underflow of the finite buffer. In this paper, we propose an auto regulated data provisioning model based on receiver-driven data pull model. On this model, we provide a synchronized data replenishment mechanism that implicitly avoids the data buffer overflow as well as explicitly regulates the data buffer underflow by adequately adjusting the buffer resilience. To estimate the optimal size of buffer resilience, we exploits an adaptive buffer resilience control scheme that minimizes both data buffer space and idle time of the processing elements based on directly measured sample path analysis. The simulation results show that the proposed scheme provides allowable approximation compared to the numerical results. Also, it is suitably efficient to apply for such a dynamic environment that cannot postulate the stochastic characteristic for the data transfer time, the data processing rate, or even an environment where the fluctuation of the both is presented.

• ETRI Journal
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• v.43 no.3
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• pp.447-458
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• 2021

The quality of experience (QoE) of video streaming is degraded by playback interruptions, which can be mitigated by the playout buffers of end users. To analyze the impact of playout buffer dynamics on the QoE of wireless adaptive hypertext transfer protocol (HTTP) progressive video, we model the playout buffer as a G/D/1 queue with an arbitrary packet arrival rate and deterministic service time. Because all video packets within a block must be available in the playout buffer before that block is decoded, playback interruption can occur even when the playout buffer is non-empty. We analyze the queue length evolution of the playout buffer using diffusion approximation. Closed-form expressions for user-perceived video quality are derived in terms of the buffering delay, playback duration, and interruption probability for an infinite buffer size, the packet loss probability and re-buffering probability for a finite buffer size. Simulation results verify our theoretical analysis and reveal that the impact of playout buffer dynamics on QoE is content dependent, which can contribute to the design of QoE-driven wireless adaptive HTTP progressive video management.