• Journal of the Korean Statistical Society
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• v.34 no.1
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• pp.39-47
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• 2005

We adopt the P/sub λ, T//sup M/ policy of dam to introduce a service policy with alternating service rates for a Poisson arrival queue, in which the service rate alternates depending on the number of customers in the system. The stationary distribution of the number of customers in the system is derived and, after operating costs being assigned to the system, the optimization of the policy is studied.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2001.05a
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• pp.39-42
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• 2001

This paper we study the exact controllability for the nonlinear fuzzy control system in E$^{2}$$_{N}$ by using the concept of fuzzy number of dimension 2 whose values are normal, convex, upper semicontinuous and compactly supported surface in R$^{2}$.>.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.9
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• pp.663-670
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• 1988

Advances in VLSI technology have made it possible to have a larger number of processing elements to be included in highly parallel processor system. A system with a large number of processing elements and memory requires a complex data path. Multistage Interconnection networks(MINS) are useful in providing programmable data path between processing elements and memory modules in multiprocessor system. In this thesis, the performance of MINS for the star network has been analyzed and compared with other networks, such as generalized shuffle network, delta network, and referenced crossbar network.

• Quality Improvement in Health Care
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• v.1 no.2
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• pp.44-59
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• 1994

Medical consumers(patients) want evening-clinic because of busy work. For patient's convenience and improving service, hospital should accept it. Considering payment system and patient's demand, personnel expenses, hospital can not accept. The practice of shift system to accept patient's demand and hospital's economic aspect was made. To analysis the effect of the system and probability to alternative to evening clinic this study was done. This study was composed of basal study, intervention, evaluation of effect. The basal study were composed of studying demand on evening clinic, the number of beds, doctors employee, the time table of practice and work, and the number of patients at arrival time. The intervention composed of changing of practice time, changing of working time by the number of patients at arrival time, increasing of employee. The evaluation of effect were composed of evaluating the number of patient at time, the effect of shift system, the comparison of the number of in and out patients and questionnairing the practice of shift system. In the practice time at 2 shift system First team works 7-15 hours and Second team 12-20 hours. there are no lunch and supper time. At 18-20 hours the number of patients were 25-30. The number of patient a depart were 6-7. The number of out-patient increase in 13% and inpatient increase in 10% before the system. Doctors(100%), employee(94.6%), and patients(86.4%) approved this system. The advantage of this system were utilization of surplus time, lengthen the practice time, even distribution of patients and shortening of waiting time, rapid treatment of emergent patients. The disadvantage of this system were shortage of manpower, not all depart practice, continuity of practice, no lunch and supper time, irregular rounding. At present because of small Demanding on evening clinic, this shift system was economical. To succeed this study more effectively all depart in hospital participate. But because of economical reason it is impossible for hospital to do it. If the government assist the economic loss that all depart participate in this system it is very helpful for hospital to succeed in implementing this system more early.

• IE interfaces
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• v.15 no.4
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• pp.460-473
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• 2002

The objective of this paper is to design a Goal Alternatives Disposition System having three main subsystems for setting, evaluating and selecting goal alternatives. For setting of goal alternatives, System Alternatives Tree(SAT) structure will be developed, which has a computation algorithm for setting decision alternatives by the concept of System Priority Number(SPN). For evaluating and selecting of goal alternatives; First, Normative and Exploratory Priority Indices which consider technical performance to the goal, cost and feasibility are developed respectively. Second, Integrated Priority Index is built up to determine the total priority of the Goal Alternatives Disposition(GAD) system. For the design and verification of the GAD system, technological forecasting structure theory, systems engineering methodology will be used.

• Journal of Applied Reliability
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• v.14 no.4
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• pp.225-229
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• 2014

A one-shot device is defined as a product, system, weapon, or equipment that can be used only once. After use, the device is destroyed or must undergo extensive rebuild. Determining the reliability of a one-shot device poses a unique challenge to the manufacturers and users due to the destructive nature and costs of the testing. This paper presents a reliability growth prediction for a one-shot system. It is assumed that 1) test duration is discrete(i.e. trials or rounds); 2) trials are statistically independent; 3) the number of failures for a given system configuration is distributed according to a binomial distribution; and 4) the cumulative expected number of failures through any sequence of configurations is given by AMSAA model. When the system development is represented by three configurations and the number of trials and failures during configurations are given, the AMSAA model parameters and reliability at configuration 3 are estimated by using a reliability growth analysis software. Further, if the reliability growth predictions do not meet the target reliability, the sample size of an additional test is determined for achieving the target reliability.

• Journal of the Korean Operations Research and Management Science Society
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• v.31 no.3
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• pp.63-79
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• 2006

In this study we consider a CONWIP system in which the processing times at each station follow a Coxian distribution and the demands for the finished products arrive according to a compound Poisson process. The demands that are not satisfied immediately are either backordered or lost according to the number of demands that exist at their arrival Instants. For this system we develop an approximation method to calculate performance measures such as steady state probabilities of the number of parts at each station, proportion of lost demands and the mean number of backordered demands. For the analysis of the proposed CONWIP system, we model the CONWIP system as a closed queueing network with a synchronization station and analyze the closed queueing network using a product-form approximation method. A recursive technique is used to solve the subnetwork in the application of the product-form approximation method. To test the accuracy of the approximation method, the results obtained from the approximation method are compared with those obtained by simulation. Comparisons with simulation show that the approximation method provides fairly good results.

• Journal of Korean Institute of Industrial Engineers
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• v.36 no.2
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• pp.138-145
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• 2010

In this paper, we consider the information processing system, which organizes the collected data to meaningful information when the number of data collected from multiple sources reaches to a predetermined number, and performs any action by processing the collected data, or transmits to other devices or systems. We derive an analytical model to calculate the time until it takes to process information after starting to collect data. Therefore, in order to complete the processing data within certain time constraints, we develop some design criteria to control various parameters of the information processing system. Also, we analyze the discrete time model for packet switching networks considering data with no particular arrival nor drop pattern. We analyze the relationship between the number of required packets and average information processing time through numerical examples. By this, we show that the proposed model is able to design the system to be suitable for user's requirements being complementary the quality of information and the information processing time in the system with time constraints.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.10
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• pp.78-88
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• 1990

To evaluate the performance of a multiprocessor system, a discrete event model of memory interference in the system employing multiple-bus interconnection networks is proposed. An analytic model of the system is presented and then simulator models are implemented for cross-verifying the analytic results and simulation results. The simulator model takes as input the number of processors, the number of memory modules, the number of buses and the local memory miss ratio. The model produces as output the memory bandwidth, the processor, memory module and bus utilization and the bus contention ratio. Using the model in the design of the system, it is possible to evaluate the system performance by analyzing the interaction of the input parameters.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.1256-1259
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• 2002

In this paper, we have proposed license plate recognition system for multi-national vehicle license plate using geometric features along with hybrid and seven segment pattern vectors. In the proposed system, we suggested to find horizontal and vertical relation after going through preparation process with inputted real-time license plate image of Korea and Japan, and then to classify license plate with using characteristic and geometric information of license plates. It classifies the extracted license plate images into letters and numbers, such as local name, local number, classification character and license consecutive numbers, and recognize license plate of Korea and Japan by applying hybrid and seven segments pattern vectors to classified letter and number region. License plate extraction step of the proposed system uses width and length information along with relative rate of Korean and Japanese license plate. Moreover, it exactly segmentation by letters with using each letter and number position information within license plate region, and recognizes Korean and Japanese license plates by applying hybrid and seven segment pattern vectors, containing characteristics related to letter size and movement within segmented letter area. As the result of testing the proposed system in real experiment, it recognized regardless of external lighting conditions as well as classifying license plates by nations, Korea and Japan. We have developed a system, recognizing regardless of inputted structural character of vehicle licenses and external environment.