• 전자공학회논문지 IE
• /
• 제48권4호
• /
• pp.47-52
• /
• 2011

본 논문에서는 다양한 형태의 서비스를 고려한 호 수락 방법에 대해 셀룰라 시스템 성능을 분석하였다. 본 연구에서는 호수락 제어 방법으로 등가대역 개념에 신규호의 차단률과 핸드오버호의 절단률에 따라 대역폭을 가변 시키는 방법을 사용하였다. 컴퓨터 시뮬레이션으로 이 호 수락 방법을 사용하여, 핸드오버 호를 위해 자원예약을 두고 또한 수락되지 않는 호는 버퍼에 대기시킴에 따른 시스템의 성능을 살펴보았다.

• Journal of applied mathematics & informatics
• /
• 제6권3호
• /
• pp.943-952
• /
• 1999

Models of single-server queues with vacation have been widely used to study the performance of many computer communica-tion and production system. In this paper we use the formula for a wide class of vacation policies and multiple types of vacations based on the M/G/1 queue with generalized vacations and exhaustive service. furthermore we derive the waiting times for many complex vacation policies which would otherwise be to analyze. These new results are also applicable to other related queueing models. if they conform with the basic model considered in this paper.

• 전자공학회논문지A
• /
• 제32A권5호
• /
• pp.42-53
• /
• 1995

Token bus protocols have been sidely accepted for Medium Access Control (MAC) in real-time networks such as those used in factory automation, distributed process control, nuclear power plant, aircraft and spacecraft. Token bus protocols provide timer-controlled priority mechanism, which offers multiple level of privilege of medium access to different type of traffic. This paper presents and approximate analytical model for the evaluation of variance of waiting time in the time-controlled proiority scheme of token bus protocols. Token bus system is assumed to be operated with singe-service discipline which is the practical case of real-time networks such as those used in distributed process control and factory automations. The approximate analytical model is validated by comparison with the simulation resuls.

• 한국국방경영분석학회지
• /
• 제12권1호
• /
• pp.87-105
• /
• 1986

Among the various types of waiting line systems, the elevator servicing system is quite different from the usual queueing system in view of the service characteristics. For example, the FIFO discipline is not always valid depending upon the situation when the direction of first-come customer's is opposite of the operating elevator direction and at that time a later-arrived one has a luck to be served first. In this paper, a simulation model is constructed and tested by the sample data and the results have turned out to be fairly adequate. This model, therefore, will provide a good guide to anyone who is interested in the decision of optimal location selection of no-passenger elevator in high buildings whatsoever. This model is also available, with slight modification, to the problem of city bus dispatching or any other waiting line problems where the servicing equipments are moving.

• Nuclear Medicine and Molecular Imaging
• /
• 제40권2호
• /
• pp.53-57
• /
• 2006

Radionuclide therapy has been used for more than 50 years and proved to be a safe and effective modality. However, the patients' right to have the excellent medical service is seriously disturbed by excessive regulations of government institutions such as Korea Institute of Nuclear Safety (KINS), Health Insurance Review Agency (HIRA) and Korea Food and Drug Administration (KFDA). For example, the patients should wait for more than 6 months to have I-131 treatment in many hospitals it is strongly recommended to mitigate the regulations to resonable levels to solve the problems. If HIRA allow the hospitals to charge reasonable rate for radionuclide therapy room, then more hospitals would invest to build the radionuclide therapy rooms and the patients' waiting time would decrease. The waiting time would also decrease, if KINS allow 2 patients to share a radionuclide therapy room. Finally, it is strongly recommended to lower the threshold for approval of new therapeutic radiopharmaceuticals by KFDA, which would allow new effective therapeutic raoiopharmaceuticals to be introduced to clinical practices more easily.

• 대한디지털의료영상학회논문지
• /
• 제13권3호
• /
• pp.127-132
• /
• 2011

This is to improve the complicate process of the existing CD copy flow in Department of Radiology. It is also to improve the medical service of the hospital to secure private information of patients. Survey: The patients who ask for CD copies in the Department of Radiology of this hospital(for 6 months in 2010). Time: Comparing the total amount of time of the previous and the modified CD copy flow. Using the SPSS 12.0 program for testing significance of independent two-samples t-test. Private information: Introducing the identification-system based on the medical law to supplement the security of personal information of patients. There was manifold complaints due to receipt and issuing the prescription in Admission and Discharging office and outpatient department. The time has been approximately 50% reduced from 70 mistunes to 32 mistunes due to simplifying the routes. The security of the personal information has been supplemented by let patients submit documentary evidence based on the medical law. The service in the hospital has been improved as a result of simplifying the whole process of the routes and receipt process. Therefore, the each stage of waiting time has been decreased. In addition, the personal information of the patients has been more secured.

• 한국시뮬레이션학회논문지
• /
• 제28권3호
• /
• pp.65-74
• /
• 2019

분기-접합 생산시스템은 오랜 기간 동안 연구되어왔지만, 개별 또는 공유 유한 버퍼를 갖고 일반공정시간 분포를 따르는 시스템에 대한 분석은 제한적이다. 일반적으로 대기행렬 이론적 분석법은 유한 버퍼를 갖는 시스템에 대한 분석에는 어려움이 있다. 본 연구에서는 max-plus 대수적 분석법을 활용하여 일반 공정시간을 갖는 버퍼 공유 분기-접합 생산시스템을 분석하였다. 하지만, 이러한 분석법은 특성치 계산의 관점에서는 적절한 방법을 제공하지 못하기 때문에 max-plus 대수로 도출된 표현식과 @RISK 소프트웨어를 활용하여 스프레드시트 시뮬레이션 모형을 개발하였다. 시뮬레이션 실험을 통해 유한 버퍼와 두 가지 차단규칙인 BBS(통신차단)과 BAS(제조차단) 하에서 시스템 대기시간에 대한 몇몇 특성을 비교 분석하였다.

• 한국경영과학회지
• /
• 제24권2호
• /
• pp.31-39
• /
• 1999

A new approximation method for finding the steady-state probabilities of the number of customers present in queueing systems with Poisson arrivals and two servers with different deterministic service times with infinite waiting room capacity is developed. The major assumption made for the approximation is that the residual service times of the servers have mutually independent uniform distributions with densities equal to the reciprocals of the respective service times. The method reflects the heterogeneity of the servers only through the ratio of their service times, irrespective of the actual magnitudes and difference. The transition probability matrix is established and the steady-state probabilities are found for a variety of traffic intensities and ratios of the two service times; also the mean number of customers present in the system and in the queue, and server utilizations are found and tabulated. The method was validated by simulation and turned out to be very sharp.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2002년도 ITC-CSCC -2
• /
• pp.1074-1077
• /
• 2002

This paper proposes an adaptive pricing system with scheduling to balance the demand for contents and to realize an effective use of resources in contents delivery networks. In the proposed adaptive pricing system, the table of the service levels and prices (tariff) is shown to each user at the start of service and each user chooses one of the service classes. These prices are decided adaptively reflecting the congestion state of the networks. Then, by the proposed scheduling algorithm, these requests are scheduled so as to keep the service level agreements completely.

• 아태비즈니스연구
• /
• 제10권4호
• /
• pp.181-195
• /
• 2019

This study aims to investigate the influencing attributes on price fairness in the domain of fast food service context. As the research subject, this research selects McDonald's business because of its market share in the fast food market. Five attributes are examined to account for price fairness. The attributes are advertising attitude, employee service, waiting, convenience, and brand love. This study performed survey to collect the data. The survey participants are university students because they are essential market segment for fast food business. The number of observation is 299 for the data analysis. To analyze the data, this research used various statistical instruments (e.g., frequency analysis, mean and standard computation, exploratory factor analysis, reliability test, correlation matrix, and multiple regression analysis). Regarding the results, this research identified advertising attitude, employee service, and brand love are influential attributes to establish price fairness of university students. This research could inform the marketing director of food service business to understand university students target better.