• The Transactions of the Korea Information Processing Society
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• v.7 no.11
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• pp.3479-3489
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• 2000

Most of the study on fairness control method for Distributed-Queue Dual-Bus(DQDB) have been performed under specific load types such as equal probability load types or symmetric load types. On Web-based internet enviroments client-server load types are more practical traffic patlerns than specrfic load types. In this paper, an effiective fairness control method to distribute DQDR network bandwidth fairly to all stations under a client-server load is proposed. In order to implement a dynamic bandwidth timing capabihty needed to distribute the bandwidth fairty at heavy loads, the proposed method uses two pararnetexs, one is an access hrnit to legulate each station's packet transmission and the other is the number of extra emply slots that are yielded to downstream stations. In point of implementation this mechanism is simpler and easier than Bandwidth Tuning Mechanism(BTM) that uses an intermediate pattern and an adptation function. Simulation results show that it outperforms othen mecharusms.

• The Transactions of the Korea Information Processing Society
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• v.6 no.12
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• pp.3652-3661
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• 1999

To support multimedia applications such as a multimedia communication systems and multimedia broadcasting, an operating system need to predict their timing-constraints. So, In this real-time systems, we must solve the priority inversion problem that may make the behavior of unpredictable systems and need a real-time server model that provides a better preemptability and minimizes a system overhead. In current real-time systems, the single thread server model, the worker model and the dynamic server model are being used for synchronization but they cannot propose an effective structure for managing shared resources. In this paper, the priority inheritance protocol is used to solve the priority inversion problem and the hybrid prioritized worker model is proposed, which can provide a more effective structure and a faster response time minimizing a system overhead. The hybrid prioritized worker model is to combine the static and the dynamic prioritized worker model, and have a better performance than other models in response time which is an important factor in a real-time system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.7
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• pp.1561-1568
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• 2005

In client-solver environments, clients can execute applications without contact a server by storing data in its cache. To guarantee correction of applications, we need a cache consistency algorithm. Many cache consistency algorithms have been proposed, these were categorized by detection-based and avoidance-based algorithms. In this paper, we propose a new detection-based cache consistency algorithm that can reduce a burden of a client that has poor resource compare with a server Our method controls concurrency of transactions using timestamp ordering and updates a cache dynamically. In addition to we show that our method maintains a one-copy serializability.

• The KIPS Transactions:PartD
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• v.9D no.1
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• pp.145-152
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• 2002

Recently most of the home and small-size company use ADSL(Asymmetric Digital subscriber Line) or Cable Modem for using Internet Services. The number of Internet IP Address in current Internet IP Address System(IPv4) that is consisted of 4byte is almost empty, so generally the IP Address assigned dynamically is used. This way is just OK in general uses, but not OK in Internet Servers operation. This paper designed the gateway(Gate-D) system which is enable any system that get IP Address assigned dynamically to serve Internet Server Services(Telnet, FTP, HTTP, Mail, etc …), and made sure the worth by using Telnet Server.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.10B
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• pp.854-861
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• 2003

In this paper, we proposed the fuzzy control algorithm for efficient buffer control about traffic that is connected in ATM networks. The proposed Fuzzy control algorithm has total traffic arrival ratio, buffer occupancy ratio and Fuzzy set to search for dynamic service rates in server. That is, is based on Fuzzy logic according to the arrival ratio of total traffic and buffer occupancy ratio that is happened and reasoning. Then, made reasoning result control service rates in server about traffic that is connected with defuzzification value. Performance analysis result: it was confirmed that with the proposed scheme, performance improves at cell loss rate, when compared with the existing PBS scheme.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.91-94
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• 2011

The LBSNS(Location-Based Social Networking Service) service has been well-received by researchers and end-users, such as Twitter. Location-Based service of Twitter is now structured that users could not subscribe the information of their interesting local area. Those who being following from someone tweet message included information of local area to them just for their own interesting. However, follower may receive that kind of tweet. In order to handle the problem, we propose filtering technique using spatial join. The first work for filtering technique is to add a location information to tweets and users. In this paper, location information is represented by MBR(Minimum Bounding Rectangle). Location information is divided into dynamic property and static property. Suppose that users are continuously moving, that means one of the dynamic property's example. At this time, a massive continous query could cause the problem in server. In this paper, we create Virtual Grid on Google Map for reducing frequency of query, and conclude that it is useful for server.

• Journal of KIISE:Databases
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• v.27 no.2
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• pp.227-237
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• 2000

A Web database System is a large-scaled multimedia application system that has multimedia processing facilities and cooperates with relational/Object-Oriented DBMS. Conventional hypertext modeling methods and DB gateway have limitations for Web database because of their restricted versatile presentation abilities and inefficient concurrency control caused by bottleneck in cooperation processing. Thus, we suggest a Dynamic Navigation Model & Virtual Graph Structure. The Dynamic Navigation Model supports implicit query processing and dynamic creation of navigation spaces, and introduce node-link creation rule considering navigation styles. We propose a mapping methodology between the suggested hypertext model and the relational data model, and suggest a dynamic allocation scheduling technique for query processing server based on weighted value. We show that the proposed technique enhances the retrieval performance of Web database systems in processing complex queries concurrently.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.183-190
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• 2002

In this paper forest fire statistical information management system is constructed on web environment using web based GIS(Geographic Information System) technology. Though this system, general users can easily access forest fire statistical information and obtain them in visual method such as maps, graphs, and text if they have web browsers. Moreover, officials related to forest fire can easily control and manage all information in domestic by accessing input interface, retrieval interface, and out interface. In order to implement this system, IIS 5.0 of Microsoft is used as web server and Oracle 8i and ASP(Active Server Page) are used for database construction and dynamic web page operation, respectively. Also, Arc IMS of ESRI is used to serve map data using Java and HTML as system development language. Through this system, general users can obtain the whole information related to forest fire visually in real time also recognize forest fire prevention. In addition, Forest officials can manage the domestic forest resource and control forest fire dangerous area efficiently and scientifically by analyzing and retrieving huge forest data through this system. So, they can save their manpower, time and cost to collect and manage data.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10c
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• pp.225-227
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• 2000

홈 네트워크의 발달과 함께 홈 네트워크를 감시하고 제어할 수 있는 사용자 인터페이스의 구현 또한 중요한 문제로 인식되고 있다. 본 논문에서 홈 네트워크의 정보들을 정적인 자료와 동적인 자료로 분류하여, 2개의 전송채널을 이용함으로써 동적인 자료의 실시간 응답 특성을 향상시킬 수 있는 GUI 서버를 제안하고, 각 디바이스의 감시/제어 모듈을 컴포넌트화 함으로써 동적 GUI 갱신과 디바이스의 추가/삭제에 따른 실시간 응답 특성을 향상시켰다.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.2
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• pp.27-32
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• 2016

Several sensor devices have been developed for monitoring individual's health and status information and services which visualize customized information by associating applications running on smartphones with sensor devices also have been emerged. Though these applications provide similar information to a user, each sensor device has its own application caused by non-standardized packet formats. In this paper, we propose a sensor device identification for dynamic interworking between a smartphone and personal sensor devices. In the proposed scheme, we can use the same application which plays role of a client on the smartphone as changing sensor devices because server stores packet information of sensor devices.