• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.1186-1190
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• 1995

This paper is focused on the formulation of explicit closed-form functions describing the performance measures of the general flexible manufacturing system (FMS)according to the strategy of material handling system(MHS). the performance measures such as the production rate, the production lead-time and the utilization rate of the general FMS are expressed, respectively, as the explicit closed-form functions of the part processing time, the service rate of the material handling system (MHS) and the number of machine tools in the FMS. For this, the gensral FMS is presented as a generalized stochastic Petri net model, then, the moment generating function (MGF) based approach is applied to obtain the steady-state probabity formulation. Based on the steady-state formulation, the explicit closed-form functions for performance measures of the probability FMS can be obtained. Finally, the analytical results are compared with the Petri net simulation results to verify the validity of the suggested method. The paper is of significance in the sense that it provides a comprehensive formula for performance measures of the FMS even to the industry engineers and academic reademic resuarchers who have no background on Markov chain analysis method or Petrinet modeling

• ETRI Journal
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• v.32 no.3
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• pp.464-467
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• 2010

In this letter, we analyze the error performance of a mobile communication system with microdiversity and macrodiversity reception in gamma-shadowed Rician fading channels for a binary differential phase-shift keying modulation scheme. Analytical expressions for the probability density function (PDF) and moment-generating function (MGF) are derived. The average bit error probability can be calculated by averaging the conditional bit error probability over the PDF or using the MGF-based approach. Numerical results are graphically presented to show the effects of macrodiversity, correlation, number of diversity branches, and severity of both fading and shadowing.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.213-214
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• 2008

In this paper, we analyze the performance of a cooperative communication wireless network over independent and identically distributed (IID) Nakagami-m fading channels. A simple transmission scheme is considered where the relay is operating in amplify-forward (AF) mode. A closed-form expression for symbol error rate (SER) is obtained using the moment generating function (MGF) of the total signal to noise ratio (SNR) of the transmitted signal with binary phase shift keying (BPSK).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.653-657
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• 1994

A symbolic performance analysis approach for flexible for manufactring systems (FMS) can be formulated based on the integration of Petri Nets (PN) and moment generating function (MGF) concept. In this method, generalized stochastic Petri Nets are used to define performance models for FMS, then MGF nased approach for evaluating stochastic PN is used to derive performance parameters of PN, and finally system performance is calculated. A GSPN model of machine cell is shown to illustrate the proposed method for evaluating such performance indices as production rate, utilization, work-in-process and lead time. The major advantage of this method over existing performance evaluation of FMS is the ability to compute symbolic solutions for performance. Finally future research toward automating performance measure for GSPN models of FMS is discussed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.9
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• pp.3412-3431
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• 2015

This paper considers the effect of co-channel interference on hybrid satellite-terrestrial relay network. In particular, we investigate the problem of amplify-and-forward (AF) relaying in hybrid satellite-terrestrial link, where the relay is interfered by multiple co-channel interferers. The direct link between satellite and terrestrial destination is not available due to masking by surroundings. The destination node can only receive signals from satellite with the assistance of a relay node situated at ground. The satellite-relay link is assumed to follow the shadowed Rice fading, while the channels of interferer-relay and relay-destination links experience Nakagami-m fading. For the considered AF relaying scheme, we first derive the analytical expression for the moment generating function (MGF) of the output signal-to-interference-plus-noise ratio (SINR). Then, we use the obtained MGF to derive the average symbol error rate (SER) of the considered scenario for M-ary phase shift keying (M-PSK) constellation under these generalized fading channels.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.11A
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• pp.1053-1062
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• 2008

This paper provides a general and compact expression for the probability density function (pdf) and the moment-generating function (MGF) of the maximal ratio combiner output over Rayleigh fading channels. It is then used to derive closed form expression bit error rate (BER) for M-PSK, M-PAM and M-QAM, respectively. A variety of simulations is performed and shows that they match exactly with analytic ones.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.155-156
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• 2008

This paper provides a general and compact expression for the probability density function (pdf) and the moment-generating function (MGF) of the maximal ratio combiner output over Rayleigh fading channels. It is then used to derive closed form expression outage probability for repetition code problem. A variety of simulations is performed and shows that they match exactly with analytic ones.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.24 no.63
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• pp.65-77
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• 2001

A more technical perspective is needed in estimating the effect of the Manufacturing Process for improving the Productivity, there are many statistical evaluation methods, convenience sampling, frequencies, histogram, QC seven tools, control chart etc. It is more important for the companies to use six sigma to reduce defective and improve the process control than the technical definition as a disciplined quantitative approach for improvement of process control and a new way of quality innovation. Process network analysis is a technique which has the potentiality for a wide use to improve the manufacturing process which other techniques can't be used to analyze effectively. It has some problems to analyze the process with feedback loops. The branch probabilities during quality inspections depend upon the number of times the product has been rejected. This paper presents how to improve the manufacturing process by statistical process control using branch probabilities, Moment Generating Function(MGF) and Sensitivity Equation.