• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.9B
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• pp.591-595
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• 2005

In this paper, we propose the fairness improvement leaky bucket (PILB) algorithm as a traffic policing mechanism. In the proposed algorithm, there is a cell buffer for every ATM connection in order to store date cells. Network decides whether an ATM connection obeys the contracted traffic parameter, and stores data cells in the cell buffer if the connection obeys but is considered as violated the contract due to temporary lack of network resource. By using the proposed algorithm, we can obtain the statistical multiplexing gain that is the superiority of packet switching network. Moreover, when a connection tries to transmit more data cells by violating the contracted traffic parameters, the connection is prevented from using excess network resource, which incurs all connections sharing network resource fairly. The performance of the proposed FILB algorithm is investigated by using the simulation. The result shows that the proposed algorithm provides superior performance and all connections within a group share network resource fairly. The proposed algorithm can be applied not only the ATM network but also IP network.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.553-556
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• 2013

Currently green growth and energy saving are major issues and solution using low-power LED lighting devices are gaining popularity. There are a few standards to control these LED lighting equipment and DMX512 protocol is a typical communication control standard used. DMX512 lighting control protocol is one of standard protocols widely used in various fields which include mainly stage lighting and landscape lighting. But in DMX512 protocol, line is to be connected to a wired connection. Advantage of wired connection is stable data transfer operation but it adds complexity and certain constraints as well in wired connection. To solve this problem, wired connection can be replaced efficiently with a wireless connection but for wireless, problem of data loss and two way communications arises. In this paper, these problems of wireless communication for DMX512 have been addressed and solutions for two way communications and data loss problem have been proposed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.12B
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• pp.1042-1051
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• 2004

The IEEE1394 is a favorable protocol for A/V networks recently in home and there are two types of transmission in this protocol which are asynchronous and isochronous. The more nodes participate in the IEEE1394 network, the more problems of resource exhaustion and connection repetition may occur. So this paper proposes a middleware for isochronous connection management and reliable multimedia data transmission in the IEEE1394-IEC61883 based home networks. In this paper, proposed middleware is supporting the various types of isochronous connection, guaranteeing the reliability of isochronous connection and providing the characteristic of a real-time data transmission. We support CORBA API for multimedia service and the proposed architecture was implemented using a test-bed and we verified the proposed architecture in a test-bed.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.9
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• pp.94-105
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• 1993

In this paper propose a Koaren character recognition system using a neural network is proposed. This system is a multilayer neural network based on the masking field model which consists of a input layer, four feature extraction layers which extracts type, direction, stroke, and connection features, and an output layer which gives us recognized character codes. First, 4x4 subpatterns of an NxN character pattern stored in the input buffer are applied into the feature extraction layers sequentially. Then, each of feature extraction layers extracts sequentially features such as type, direction, stroke, and connection, respectively. Type features for direction and connection are extracted by the type feature extraction layer, direction features for stroke by the direction feature extraction layer and stroke and connection features for stroke by the direction feature extraction layer and stroke and connection features for the recongnition of character by the stroke and the connection feature extractions layers, respectively. The stroke and connection features are saved in the sequential buffer layer sequentially and using these features the characters are recognized in the output layer. The recognition results of this system by tests with 8 single consonants and 6 single vowels are promising.

• The KIPS Transactions:PartC
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• v.14C no.6
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• pp.525-536
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• 2007

Network Control Platform(NCP) and Qualify of Service Switch(QSS) are being developed to realize centralized control and management technology, which is essential for guaranteeing traffic engineering and service quality in a next generation network. This paper adopts a parallel mechanism, and a thread and object pool to achieve high-speed connection management in the existing SNMP interface between NCP and QSS. We built up a connection management test-bed in laboratory environment to validate the functionality of high-speed connection management. We also measured and analyzed a performance of connection setup delay and a completion ratio using the test-bed. We ascertain that the parallel mechanism and the object pool are the most important performance parameters to achieve high-speed connection management in the SNMP interface between NCP and QSS.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.10
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• pp.491-498
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• 2005

The Denial of Service(DoS) attacks, which are done by consuming all of the computing or communication resources necessary for the services, are known very difficult to be protected from. TCP has drawbacks in its connection establishment for possible DoS attacks. TCP maintains the state of each partly established connection in the connection queue until it is established completely and accepted by the application. The attackers can make the queue full by sending connection requests repeatedly and not completing the connection establishment steps for those requests. In this paper, we have designed and implemented the extended TCP for preventing from SYN Flood DoS attacks. In the extended TCP, the state of each partly established connection is not maintained in the queue until the connection is established completely. For the extended TCP, we have modified the 3-way handshake procedure of TCP and implemented the extended TCP in the Linux operating system. The test result shows $0.05\%$ delay more than original TCP, but it shows that the extended TCP is strong for SYN Flood attacks.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.521-526
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• 2006

As a result of establishing the regional self-government system, regional residents came to take more interest in their land ownership rights and relevant areas. The administrative bodies in South Korea are trying their best to meet the complicated and diversified demands of the residents regarding land and construction administration. However, governmental agencies are having difficulties identifying land characteristics on the field as part of standard lands change every year. Also, the vague boundaries of agricultural and mountainous land areas are causing surveyors problems in spotting the right areas. Thus, this study intends to provide information and guidance on an accurate land price calculation system in connection between the land information system and PDA technology for distribution of accurate information regarding lands and their management.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2004.11a
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• pp.189-192
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• 2004

The present much information of internet has to exist for innumerable user so that couldn't satisfy there's a variety of demand. so they have a demerit that search unnecessary information. However Web service is different with other mass media because It is possible that enable Mass Customization for Personalization strategy. In The paper suggest reasoning system that detect user connection location by using indirect abstraction techniques a kind of Case-based reasoning techniques.

• The Research Journal of the Costume Culture
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• v.10 no.2
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• pp.186-199
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• 2002

This study is carried out to examine the purpose of utilization and the degree of satisfaction on the information collected from the Internet site for the understanding of the reality of clothing information for college students. The results are as fellows; 1 . Three primary factors have been abstracted for the satisfaction of information. 2. The difference in the purpose of utilizing information, depending on the individual characteristic of students and the features related to computer, was shown in the difference of major and school year, number of the internet connection per day, capability of using computer, period of using computer, and frequency of information searching. The more the number of internet connection per day, the less the capability of using computer, and searching for information when required, internet can be utilized for study and work. 3. The difference in the degree of information satisfaction, depending on the individual characteristic of students and the features related to computer, was shown in the difference of major, school year, opportunity to take computer-related course, frequency of searching information, and etc. More positive and satisfactory response was derived from these not majoring in clothing rather than those majoring, those taking computer course related to clothing, and those searching for clothing information periodically. 4. The primary factors affecting the satisfaction on the overall information of clothing show difference in terms of sex and frequency of searching information. Female students show lower degree of satisfaction than male students and more satisfaction on the information searched as the frequency of searching becomes less.

• Journal of Communications and Networks
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• v.9 no.4
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• pp.511-523
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• 2007

In broadband convergence network(BcN), heterogeneous broadband wired & wireless subnetworks and various terminal equipments will be interconnected. In order to provide end-to-end realtime multimedia services on such heterogeneous networking environment, as a result, two major problems should be resolved: i) Multimedia session establishment & negotiation that adjusts the differences in the capability of multimedia data processing at the end terminal nodes, ii) quality of service(QoS)-guaranteed connection establishment or resource reservation with connection admission control(CAC) in each heterogeneous subnetworks along the path. The session layer signaling(e.g., SIP/SDP) should be extended for QoS negotiation, and must be tightly cooperating with network layer signaling or resource reservation with CAC function. In this paper we propose a session and connection management architecture for the QoS-guaranteed realtime multimedia service provisioning on BcN, with Q-SIP/SDP, resource reservation protocol with traffic engineering extension, and CAC functions. The detailed interaction scenario and related algorithms for QoS-guaranteed realtime multimedia session, resource reservation and connection establishment are explained and analyzed. From the experimental implementation of the proposed scheme on a small scale BcN testbed, we verified that the proposed architecture is applicable for the realtime multimedia service provisioning. We analyze the network performance and QoS parameters in detail.