• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.12
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• pp.9-17
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• 2003

In this paper we proposea method for estimating the bandwidth in next-generation If network. Especially, we concentrate on the edge routers accommodating the VoIP connections as well as a group of data connections. Bandwidth dimensioning is carried out at call level and packet level for voice traffic in the next-generation IP network. The model incorporates the statistical estimation approach at a call level for obtaining the number of voice connections simultaneously in the active mode. The call level model incorporates a statistical technique to compute the statistics of the number of active connections such as the mean and variance of the simultaneously connected calls in the network. The packet level model represents a load map for voice and data traffic by using non-preemptive M/G/1 queuing model with strict priority for voice over data buffer, From the proposed traffic model, we can derive a graph for upper bounds on the traffic load in terms of bandwidth for voice and data connections. Via numerical experiments we illustrate the implication of the work.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.9
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• pp.807-810
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• 2001

Election Weighting Machine is used an electronic scale which has many trouble because of broken load cells. In this paper, we propose an Intelligent Diagnosis System will for an electronic weighting machine using fuzzy logic. It s purpose be detect of the load cell s trouble. The electronic circuit of system, which call junction box , will be connected resistance in a series at circuit of Wheatstone Bridge for monitoring the condition of load cells.

• Journal of the Semiconductor & Display Technology
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• v.18 no.1
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• pp.25-31
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• 2019

In this study, a new adhesion evaluating equipment and data processing methods were developed to overcome some limitations of existing evaluating equipment. Nano-diamond coated tool is a specimen of experiment. When applying frictional force and shear force on the specimen by a rotating polishing pad, delamination occurs at a moment. During each experiment, the vibration, load, and torque is obtained by accelerometer, loadcell and torque s+ kpensor. Frictional force and coefficient of friction are obtained by calculating torque and load. Based on FFT transformation, acceleration is processed and analyzed. As a result, the moment of delamination and the load at that time can be detected by the new developed equipment and measurement system. Finally, we call this load as an Adhesion force.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.9B
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• pp.892-899
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• 2009

Reuse-partitioning is a simple technique that can be used to improve the capacity of a cellular system. In the previous researches, authors do not explain how a channel is selected and what happens when there is no channel available when a call arrives. Therefore, in this paper, we describe a simple channel selection procedure and analyze the performance of a system. The performance is presented in terms of the channel utilization and call blocking probability by varying offered load per cell. Our analytical results may be added in a realistic performance analysis of reuse-partitioning-based system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.12
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• pp.3098-3108
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• 1996

This paper proposed two mechanisms of fixed method and new arrival method. They are all interactive meachanisms in that a SCP and the SSPs exchange load information for overload control. These mechanisms using simple algorithm based on the standard ACG, apply differenct call gapping time on each SSP under the fairness scheme when they allocates SCP capacity to competing demends. Also in the mechanisms, priority scheme is implemented. Two mechanisms show the almost same results on the call throughput. Fairness about the probability of rejection is maintained same value on all SSPs. On Priority scheme, new arrival method has better achievement than fixed method.

• Korean Management Science Review
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• v.10 no.1
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• pp.107-125
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• 1993

Modern telecommunication switching systems are SPC(Stored Program Control) machines handling voice, data and other kinds of traffic, in an environment which tends to be fully digital switching and transmission. The throughput of such systems is determined by the real time capacity of its centralized or distributed control processors and by the traffic capacity of the switching network. Designers must verify the traffic and call processing capacity of the switching system and check its performance under traffic load before it is put into service. Verification of traffic and call processing capacity of switching systems is one of the problems treated by teletraffic studies ; teletraffic studies are based on stochastic process, queueing theory, simulations and other quantitative methods of decision making. This study suggests the general methodology to evaluate the throughput and performance of the ISDN switching system. TDX-10 ISDN switching system are employed to give illustrative examples of the methodologies discussed in this study.

• Journal of Korean Institute of Industrial Engineers
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• v.13 no.2
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• pp.17-34
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• 1987

Modern telecommunication switching systems are SPC (Stored Program Control) machines handling voice, data and other kinds of traffic, in an environment which tends to be fully digital switching and transmission. The throughput of such systems is determined by the real time capacity of its centralized or distributed control processors and by the traffic capacity of the switching network. Designers must verify the traffic and call processing capacity of the switching system and check its performance under traffic load before it is put into service. Verification of traffic and call processing capacity of switching systems is one of the problems treated by teletraffic studies; teletraffic studies are based on stochastic process, queueing theory, simulations and other quantitative methods of decision making. This paper reviews the general methodologies to evaluate the throughput and performance of the digital switching system. TDX-10, which is a fully digital switching system under development in ETRI, is employed to give illustrative examples of the methodologies discussed in this paper.

• Journal of Korea Society of Industrial Information Systems
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• v.18 no.1
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• pp.1-9
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• 2013

Most calls of a called user are invoked by the group of calling users. This call pattern is defined as call locality. Similarly Internet sessions including IP telephony calls have this pattern. We define it session locality. In this paper, we propose a caching scheme to support session locality in hierarchical SIP networks. The proposed scheme can be applied easily by adding only one filed to cache to a data structure of the SIP mobility agent. And this scheme can reduce signaling cost, database access cost and session setup delay to locate a called user. Moreover, it distributes the load on the home registrar to the SIP mobility agents. Our performance evaluation shows the proposed caching scheme outperforms the hierarchical SIP scheme when session to mobility ratio is high.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.445-450
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• 2003

This study was performed 10 develop the accelerated life test method using Weibull-IPL(Inverse Power Law) model for mechanical components. Weibull-IPL model is concerned with determining the assurance life with confidence level and the accelerated life test time From the relation of weibull distribution factors and confidence limit, the testing times on the no number of failure acceptance criteria arc determined. The mechanical components generally represent wear and fatigue characteristics as a failure mode. IPL based on the cumulative damage theory is applied effectively the mechanical components to reduce the testing time and to achieve the accelerating test conditions. As the actual application example, accelerated life test method of agricultural tractor transmission was described. Life distribution of agricultural tractor transmission was supposed to follow Weibull distribution and life test time was calculated under the conditions of average life (MTBF) 3,000 hours and 90% confidence level for one test sample. According to IPL, because test time call be shorten in case increase test load test time could be reduced by 482 hours when we put the load 1.1 times of rated load than 0.73 times of rated load that is equivalent load calculated by load spectrum of the agricultural tractor. This time, acceleration coefficient was 11.7.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.250-253
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• 1989

As the necessity of increasing the midnight base load is extensively increased, electric power companies have to increase the demand of midnight electrical power by lowering the electrical charge rate at midnight. One of the most widely used midnight equipments is the heat Storage type's electrical boiler. A Single chip microprocessor controller for the heat-storage type's electrical boiler is developed. This controller call reduce the undesirable peak load at the begining of midnight (i.e.11 P.M.) time band by using backward load control method. Futhermore, this controller enables reservation of heat storge and the effective heating control the field test has been done by use the boiler for 66$m^2$ with the heater of 21KW quality.