• Journal of the Korea Society for Simulation
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• v.24 no.3
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• pp.27-35
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• 2015

We analyze an M/G/1/K queueing system with queue-length dependent service and arrival rates. There are a single server and a buffer with finite capacity K including a customer in service. The customers are served by a first-come-first-service basis. We put two thresholds $L_1$ and $L_2$($${\geq_-}L_1$$ ) on the buffer. If the queue length at the service initiation epoch is less than the threshold $L_1$, the service time of customers follows $S_1$ with a mean of ${\mu}_1$ and the arrival of customers follows a Poisson process with a rate of ${\lambda}_1$. When the queue length at the service initiation epoch is equal to or greater than $L_1$ and less than $L_2$, the service time is changed to $S_2$ with a mean of $${\mu}_2{\geq_-}{\mu}_1$$. The arrival rate is still ${\lambda}_1$. Finally, if the queue length at the service initiation epoch is greater than $L_2$, the arrival rate of customers are also changed to a value of $${\lambda}_2({\leq_-}{\lambda}_1)$$ and the mean of the service times is ${\mu}_2$. By using the embedded Markov chain method, we derive queue length distribution at departure epochs. We also obtain the queue length distribution at an arbitrary time by the supplementary variable method. Finally, performance measures such as loss probability and mean waiting time are presented.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.229-232
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• 1998

Modern telecommunications are increasingly demanding the addition of complex switching features to switching system software. These improvements also should satisfy customer demands for quick provisioning of new service features. But whenever we have developed the switching system in various types, we met problems that are lack of system engineers and short developments terms. We need new guidelines of software design to meet the demands and overcome our problems. So we propose new software platform, scenario driven call control engine (SDCCE) for ATM switching system software and implement an effective call control software using scenarios for ATM Switching System. A scenario is a set of procedures and supplementary scenarios written in data structure and gives benefits to easy adapt new or modified function by adding a scenario. The goal of SDCCE is to increase reusability and readability of software. Especially, it gives a good software extensibility and maintainability. And when we developed ptmp call processing control software, we could get high productivity by reusing scenarios and procedures of ptp call processing control software. We applied the scenario driven call control software to ATM switching system.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.28 no.2
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• pp.53-59
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• 2005

The environment of If is, currently, on its developing process to the period of Web Service, Ubiquitous, and Telemetics which not only enable computer and internet to be utilized like the water or the air, but also be a new motivating force for its advance. In the respect of various interactions and User Interface, however, it is requiring more demands from its users, and additional functions which cannot be provided by the Web Browser. It is required a new model for supplementary of the limitation of Web_based according to their customers' requirement, to enrich the good aspects of Client-Server System, and accept such various intricate requirements. It is X-Internet, which has born with these requirements. In this study, therefore, it will be suggested a productive development framework and a method to perform the project on Rich-Thin Client Platform of X-Internet Based.

• Journal of the Korean Home Economics Association
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• v.48 no.9
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• pp.113-123
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• 2010

This study describes the beginning and further development of a collection web-based materials for an efficient approach to culinary practice education. A database was created using a five-step process of analysis, design, development, operation and evaluation. The menu for the web-based culinary practice educational materials included cooking basics, the real status of cooking, cooking related knowledge, performance evaluation, a data room and a bulletin board. As at 30 July, 2010, the datadase of educational materials, contained a total of 571 items. These comprised 139 cooking pictures, 33 recipes, 22 cooking videos, 74 cooking animations, 57 collections of basic knowledge, 14 evaluation reports, 21 supplementary textbooks, and 211 sets of other related information. The webbased materials are adequate for culinary education purposes, and their use is expected to be very highly valued.

• The Journal of the Korean dental association
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• v.48 no.2
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• pp.91-94
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• 2010

Regarding the improvement of the dental specialist program, two related issues were reviewed extensively: (a) bill amending portions of the Medical Service Act as proposed by national assemblywomen Choi Yeong-hui (Democratic Party) and Chung Mi-gyeong (Grand National Party), and; (b) Plans to supplement the submitted bill. Although the existing bill's prospects in the assembly are unclear at this point, both the existing and planned supplementary bills zero in on two points: (a) specialists must focus on providing care only in their respective expertise, and; (b) a distinction between the roles played by the primary, secondary, and tertiary medical institutions must be made to help establish clearly the country's overall health care system. In addition, proposals were made for medical license renewal among specialists so that professionals can offer better health care to customers.

• Journal of information and communication convergence engineering
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• v.8 no.5
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• pp.524-527
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• 2010

As the GPS(Global Positioning System) vulnerabilities were introduced, alternative systems to GPS backup have been studied for several years. Enhanced Loran(eLoran) as the worldwide ground-based supplementary radio navigation system was recommended as the cost effective alternative to GPS backup. Many efforts on adoption of eLoran as GPS backup have been presented. The US has been the leading role and announced that 70% enhancement for eLoran was established last year. However, the Obama administration cut off the eLoran budget on the fiscal year 2010 budget proposal while GAO's reports submitted that GPS service gap would be possible just some years later. Besides the US's condition, there are still many positive opinions on eLoran to GPS backup. This paper introduces the historical and technical aspects of eLoran and Korea's research topics.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2017.11a
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• pp.64-65
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• 2017

최근 1인 미디어인 개인방송은 무선통신망과 스마트폰 등의 발달로 현재 많은 사람들이 이용하고 있는 인터넷 서비스 중 하나이다. 개인방송이 인기를 끌고 있는 가장 큰 이유는 방송을 진행하는 브로드캐스터와 시청자가 실시간으로 소통하며 양방향 서비스를 제공할 수 있기 때문이다. 하지만 기존의 플랫폼에서는 단순히 시청자들의 채팅을 통해서만 양방향 소통을 진행한다는 한계점이 존재한다. 이에 본 논문은 채팅로그뿐만 아니라 시청자들의 사진, 카메라 롤, 영상, 음성의 링크를 채팅창에 띄우고 부가정보서비스 창을 구축하여 다양한 의견을 공유할 수 있게 되고 브로드캐스터 컨트롤 시스템을 이용하여 부가정보서비스를 제어할 수 있게 됨으로써 한층 더 흥미로운 방송을 운용할 수 있게 하는 프레임워크를 연구하였다.

• Journal of applied mathematics & informatics
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• v.22 no.1_2
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• pp.523-533
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• 2006

We analyze two finite buffers queueing system with priority scheduling dependent upon queue length. Customers are classified into two types ( type-l and type-2 ) according to their characteristics. Here, the customers can be considered as traffics such as voice and data in telecommunication networks. In order to support customers with characteristics of burstiness and time-correlation between interarrival, the arrival of the type-2 customer is assumed to be an Markov- modulated Poisson process(MMPP). The service order of customers in each buffer is determined by the queue length of two buffers. Methods of embedded Markov chain and supplementary variable give us information for queue length of two buffers. Finally, performance measures such as loss and mean delay are derived.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.315-316
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• 2023

In the present investigation, the chloride ion penetration resistance of nuclear power plant concrete with varying water-to-cement ratios was assessed. A comparative analysis was conducted on concretes that do not incorporate supplementary cementitious materials, such as fly ash, using permanently decommissioned nuclear structures as a reference. The objective is to employ this acquired data as a fundamental resource for the evaluation of the residual service life of nuclear power plant structures in subsequent studies.

• Journal of Broadcast Engineering
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• v.13 no.6
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• pp.817-827
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• 2008

The terrestrial-digital multimedia broadcasting(T-DMB) is now provided for the public service and the number of receivers reaches 15 million at the present of August 2008. The service of T-DMB itself has been succeeded in the presence. It is however remained as a supplementary role of stationed TV. It is necessary to find an additional business model as a new media to acquire surplus escaping from the deficit of the present T-DMB service. In the present paper, data service of T-DMB is proposed as candidate of such solution. Especially, TTI(Traffic and Travel Information) service is proposed as a killer application using TPEG(Transport Protocol Experts Group). At present, TPEG has not been so popular in the sense of various user satisfaction. Thus the variety of service including bi-directional service using DMB2.0 as in the sphere of Web2.0 is necessary for the service providers. In the paper, the restriction of TPEG-POI(Point of Interest) application service using the conventional mobile communication infrastructure is indicated. To overcome such restriction, TPEG-UCM(User Created Message) application service model using individual bi-directional media which is initiated and interacting by the users is proposed. In the experiment, the application program shows the usability of the proposed method so that the implementation results show its operability.