• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.10B
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• pp.1675-1689
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• 2000

We present CReMeS a CORBA-compliant design and implementation of a new real-time communication service. It provides for efficient predictable and scalable communication between information producers and consumers. The CReMeS architecture is based on MidART's Real-Time Channel-based Reflective Memory (RT-CRM) abstraction. This architecture supports the separation of QoS specification between producer and consumer of data and employs a user-level scheduling scheme for communicating real-time tasks. These help us achieve end-to-end predictability and allows our service to scale. The CReMeS architecture provides a CORBA interface to applications and demands no changes to the ORB layer and the language mapping layer. Thus it can run on non real-time Off-The-Shelf ORBs enables applications on these ORBs to have scalable and end-to-end predictable asynchronous communication facility. In addition an application designer can select whether to use an out-of-band channel or the ORB GIOP/IIOP for data communication. This permits a trade-off between performance predictability and reliability. Experimental results demonstrate that our architecture can achieve better performance and predictability than a real-time implementation of the CORBA Even Service when the out-of-band channel is employed for data communication it delivers better predictability with comparable performance when the ORB GIOP/IIOP is used.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.4B
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• pp.692-699
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• 2000

We build and analyze some types of queueing model to discuss capacity dimensioning of access links of a LAN interworking unit connected to the Internet backbone network. We assume that the IWU has a FIFO buffer to transmit IP packets to the Internet through the backbone. In order to analyze the system, we use a Poisson process and an MMPP process as input traffic models of IP packets and we use a general service time distribution as a service time model. But we use both an exponential service time and a deterministic service time in numerical examples for simple and efficient performance comparisons. As performance measures, we obtain the packet loss probability and the mean packet delay. We present some numerical results to show the effect of arrival rate, buffer size and link capacity on packet loss and mean delay.

• The Journal of the Korean dental association
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• v.53 no.10
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• pp.696-704
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• 2015

The coverage of the National Health Insurance for the elderly is expanding to denture and implants. Although the National Long-Term Care Insurance was just being settled, Oral health service was not provided to the Elderly in Long-Term Care Facilities. The long-term care facilities had part-time facility doctors. However, there is no dentist in the long-term care facility because of lack of long-term care insurance-related legislations. The amendments of long-term care insurance-related legislations for the introduction of part-time facility dentists are needed because the elderly in long-term care facility are vulnerable to oral health. For the substantial management of the National Long-Term Care Insurance, the development of oral health service model for the elderly and education materials for the dental team will be needed. Also, adequate dental service fee of the National longterm care insurance will be needed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.48
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• pp.223-232
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• 1998

In order to improve the hospital service quality, some hospitals try to reduce the outpatients' waiting time in the hospital. One of the dissatisfied service items at the hospital is the long waiting time to take the prescribed medicine. In most cases, the smaller the number of pharmacists, the longer could be the waiting time. The suggestion of criteria for optimal allocation of appropriate number of pharmacists must be very important to manage the hospital pharmacy. In this paper, we suggest the method to figure out appropriate number of pharmacists through the real situation study at the Sampling Medical Center Pharmacy. We present the simulation study results using the simulation package ARENA and the analysis of statistical distribution of the arriving prescriptions. The result of this research could be applied to the other service business to figure out the optimal allocation of available human resources and to do the job analysis for better service quality.

• 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.

• Journal of Korean Society for Quality Management
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• v.18 no.1
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• pp.21-28
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• 1990

In this paper, the capacity of system which provides the real time response call service to the customer is studied. The quality of call service depends on the response time of the service in the system. Therefore, the focus of this paper is to investigate the capacity of system under the restriction of response time. In this paper, the system is modeled by queueing network. The analytical method is applied to solve this queueing network. The solution of the model has product form solution. To get the reasonable capacities, nonlinear programming problem is formulated and is solved by GINO.

• Journal of information and communication convergence engineering
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• v.9 no.4
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• pp.353-357
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• 2011

U.S. Obama government is submit a motion to consider cyber attacks on State as a war. 7.7DDoS attack in Korea in 2009 and 3.4 DDoS attacks 2011, the country can be considered about cyber attacks. China hackers access a third country, bypassing South Korea IP by hacking the e-commerce sites with fake account, that incident was damaging finance. In this paper, for WiBro service, DDoS attacks, hackers, security incidents and vulnerabilities to the analysis. From hacker's attack, WiBro service's prognostic relevance by analyzing symptoms and attacks, in real time, Divide Red, Orange, Yellow, Green belonging to the risk rating. For hackers to create a blacklist, to defend against attacks in real-time air-conditioning system is the study of security. WiBro networks for incident tracking and detection after the packets through the national incident response should contribute to the development of technology.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.820-825
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• 2006

It is necessary to correspond to building users' claims rapidly as much as possible in order to satisfy user's need, because the final tarket of building maintenance service is user of building. This paper investigates the time taken for receiving users' claims and the time taken for the service organization to respond to the claims in the office building; types of claims and service responses are analysed, through which the response characteristics of the maintenance management organization are evaluated with respect to users' claims. Throughout extensive simulation analysis, important performance measures such as mean time to repair and utilization of maintenance personnels have been investigated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1279-1283
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• 2008

Satellite Digital Multimedia Broadcasting(SDMB) needs Gap Fillers(GFs) to cover the non-service areas. However, SDMB mobile phones which are not located in GFs service area receive signals directly from the satellite because it is impossible to cover all SDMB service with GFs. Therefore, there is a border between the GFs service coverage and the satellite service coverage and it causes a time delay in signals which are from the GFs or the satellite. The time delay is the reason why SDMB service deteriorates. In this paper, I show how to reduce the deterioration of SDMB service in the border area between the GFs and the satellite adding the time delay to the satellite signal and the GFs signal. I think that this method is helpful in reducing the deterioration, especially in the early stages of SDMB service, which the GFs are not spread all over the nation yet.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.3B
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• pp.114-129
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• 2005

In this paper, we examine Interleaved Polling with Adaptive Cycle Time (IPACT) algorithm which was proposed to control upstream traffic for Gigabit Ethernet-PONs, and we analyze the performance of the gated service and the limited service of the IPACT mathematically. For the mathematical performance analysis, we model IPACT algorithm as a polling system and use mean-value analysis. We divide arrival rate λ value into three regions and analyze each region accordingly. We obtain average packet delay, average queue size and average cycle time of both the gated and the limited service. We compare analytical results with simulation to verify the accuracy of the mathematical analysis. Upon now, simulation analysis have been used to evaluate the performance of EPONs, which require much time sud effort. Mathematical analysis can be widely used in the design of EPON systems since system designers can obtain various performance results rapidly.