• Journal of the Institute of Electronics Engineers of Korea SP
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• v.38 no.3
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• pp.80-80
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• 2001

본 논문에서는 가역가변길이 부호를 테이블 메모리에 효율적으로 저장하는 방법을 제안한다. 여러개의 부호들을 적은 개수의 값들로 테이블을 구성하는 새로운 알고리듬으로, 가역가변길이 부호의 부호내의 비트 천이개수와 부호 구성 트리에서의 레벨을 이용하는 TNWT(Transition Number and Weight of Tree)방법을 제안한다. 압축에 앞서 가역가변길이 부호들의 가중치와 천이개수를 구하고, 신장된 값들이 서로 구분이 안되는 경우를 방지하기 위해 테이블의 값들을 재배열한다. 재배열이 끝난 배열의 값들을 세 개씩 묶어 압축된 테이블을 얻는다. 압축된 테이블은 부호의 천이개수와 가중치를 이용하여 복호해 낼 수 있다. 이러한 방법을 통하여 기존의 방법보다 약 20% 적은 크기로 테이블 메모리를 구성하고, 압축된 테이블로 복호가 가능함을 확인하였다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.38 no.3
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• pp.316-324
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• 2001

A table compression method for reversible variable length code is proposed in this paper. TNWT(Transition Number and Weight of Tree) method, which uses the transition number of bits within a symbol and the level of a code tree, is proposed. Compression of table values is performed after arrangment of values that is not distinghishable by transition number and weights. In decoding, the transition number and weight of code are used. In this method, the table for RVLC decoding can be implemented with a smaller memory.

• Proceedings of the Korean Information Science Society Conference
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• 2000.04a
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• pp.445-447
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• 2000

인터넷이 급속도로 발전되면서 트래픽이 폭발적으로 증가하여 현재 라우터에 많은 부담을 주고 있다. 반면 스위칭 기술은 라우팅보다 빠르게 데이터를 전송할 수 있다. 그 결과 라우터 병목 현상을 해결하고자 IP 라우팅에 스위칭 기술을 접목한 레이블 스위칭 네트웍이 출현하게 되었다. 레이블 스위칭 기술 중 데이터 기반 레이블 스위칭에서 매우 중요한 것은 캐쉬 테이블 관리이다. 캐쉬 테이블에는 흐름 분류를 위한 정보와 레이블 스위칭을 위한 정보를 저장하고 있는데 캐쉬테이블 크기는 라우터 자원에 의해 제약을 받으므로 캐쉬 대체 기법이 필요하게 된다. 따라서 효율적인 캐쉬 테이블 관리를 위해 인터넷 트래픽 특성을 고려한 캐쉬 대체 기법에 관한 연구가 필요하다. 본 논문에서는 인터넷 트래픽 특성을 고려해 기본적인 FIFO, LFC, LRU 기법을 실제 인터넷 트래픽을 사용해 성능 평가하고 새로운 가중치 우선순위 LRU 기법을 제안한다. 특히 가중치 우선순위 LRU 기법은 플로우 인앤아웃 현상이 없고 시간이 지나도 새로운 플로우를 적절히 생성해내는 일관성을 지니면서도 스위칭 비용을 줄이는 장점을 가지고 있다.

• The KIPS Transactions:PartC
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• v.16C no.1
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• pp.27-36
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• 2009

The leaking of personal information is mostly occurred by internal users. The confidential information such as credit card number can be disclosed or modified by system manager easily. The secure storaging and managing scheme for sensitive data of individual and enterprise is required for distributed data management. The manager owning private data is needed to have a weight which is a right to disclose a private data. For deciding a weight, it is required that system is able to designate the level of user's right. In this paper, we propose the new algorithm named digit-independent algorithm. And we propose a new data management scheme of gathering and processing the data based on digit-independent algorithm. Our sharing and recovering scheme have the efficient computation operation for managing a large quantity of data using weight table. The proposed scheme is able to use for secure e-business data management and storage in ubiquitous computing environment.

• Journal of KIISE:Information Networking
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• v.31 no.2
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• pp.123-130
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• 2004

Routing and wavelength assignment(RWA) problem is an important issue in optical transport networks based on wavelength division multiplexing(WDM) technique. It is typically solved using a combination of linear programming and graph coloring, or path selection based graph algorithms. Such methods are either complex or make extensive use of heuristics. In this paper we propose a novel and efficient approach which basically obtains the maximum edge disjoint paths (EDPs) for each source-destination demand pair. And those EDPs obtained are stored in Lookup Table and used for the update of weight matrix. Routes are determined in order by the weight matrix for the demand set. The comprehensive computer simulation shows that the Proposed algorithm uses similar or fewer wavelengths with significantly less execution time than bounded greedy approach (BGA) for EDP which is currently known to be effective in practice.

• The Journal of the Korea Contents Association
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• v.10 no.9
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• pp.26-35
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• 2010

In this paper, we propose the peer indexing scheme using data dissemination considering content and mobility. The proposed scheme consists of an index table, a buddy table, a routing table to support the cost of data dissemination, the search accuracy and cost. In this proposed scheme, a neighbor peer is recognized through a signal function and the cost of data dissemination is reduced by timestamp message. The transmitted messages are stored in the index structure considering timestamp and weight of interests which improves search accuracy and reduces the cost of search.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.9
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• pp.454-460
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• 2003

In this paper, we present a novel method of parallelization of the modular multiplication algorithm to improve time and space complexity on RNS (Residue Number System). The parallel algorithm executes modular reduction using new table lookup based reduction method. MRS (Mixed Radix number System) is used because algebraic comparison is difficult in RNS which has a non-weighted number representation. Conversion from residue number system to certain MRS is relatively fast in residue computer. Therefore magnitude comparison is easily Performed on MRS. By the analysis of the algorithm, it is known that it requires only 1/2 table size than previous approach. And it requires 0(ι) arithmetic operations using 2ㅣ processors.

• Journal of KIISE:Information Networking
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• v.28 no.2
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• pp.251-261
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• 2001

The traffic on the Internet has been growing exponentially for some time. This growth is beginning to stress the current-day routers. However, switching technology offers much higher performance. So the label switching network which combines IP routing with switching technology, is emerged. EspeciaJJy in the data driven label switching, flow classification and cache table management are needed. Flow classification is to classify packets into switching and non-switching packets, and cache table management is to maintain the cache table which contains information for flow classification and label switching. However, the cache table management affects the performance of label switching network considerably as well as flowclassification because the bigger cache table makes more packet switched and maintains setup cost lower, but cache is restricted by local router resources. For that reason, there is need to study the cache replacement scheme for the efficient cache table management with the Internet traffic characterized by user. So in this paper, we propose several cache replacement schemes for label switching network. First, without the limitation at switching capacity in the router. we introduce FIFO(First In First Out). LFC(Least Flow Count), LRU(Least Recently Used! scheme and propose priority LRU, weighted priority LRU scheme. Second, with the limitation at switching capacity in the router, we introduce LFC-LFC, LFC-LRU, LRU-LFC, LRU-LRU scheme and propose LRU-weighted LRU scheme. Without limitation, weighted priority LRU scheme and with limitation, LRU-weighted LRU scheme showed best performance in this paper.

• Journal of Convergence Society for SMB
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• v.5 no.4
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• pp.5-10
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• 2015

With the advance of ICT, understanding the condition of network and analysing network monitoring have become an important issue. On the TCP/IP network, SNMP is the typical protocol that catches the condition of network by using polling method. If polling method is implemented for a long period, to catch the change of the condition of the network is not easy. On the other hand, in case of short-term polling, even if it could catch the condition of the network in real time, responsive messages to results of the polling cause the increase of traffic and therefore burden the network. There have been studies to control the overhead of responsive messages by controlling the polling period. However, not considering the characteristics of an agent, and running randomly, they cannot decrease the overhead although they would have an instant effect. This paper suggests an efficient polling method that decreases the traffic overhead of polling and catches the condition of the network in real time. Proposed method an polling for a short period and gave weight based on the characteristics of agents to catch the network condition, and a manager decided polling differentially based on the weight so that it decreased the overhead of polling traffic.

• Journal of Korea Multimedia Society
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• v.16 no.2
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• pp.119-130
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• 2013

In this paper, we propose a new color image enhancement method to improve the color saturation as well as luminance contrast in the YCbCr color space. The proposed method uses the maximum color difference table to compensate the perceived saturation changes due to luminance contrast changes. To improve the color saturation, the method first calculates the weighting factor by using the maximum color difference table and then multiplies the weighting factor to the input color difference signals. In this step, it maps color difference signals to proper color region to prevent the color distortion by considering the correlation of color saturations depending on the luminance and hue. The experimental results show that our method effectively improves color saturation compared to the conventional methods.