• Journal of Digital Convergence
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• v.12 no.12
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• pp.265-275
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• 2014

This paper introduces a new algorithms for reconstructing the suffix tree of character string, when a substring id deleted from the string or a string is inserted into the string as a substring. The algorithem has two main functions, delete-structure and insert-structure. The main objective of this algorithm is to save the time for constructing the suffix tree of an edited string, when the suffix tree of the original string is available. We tested the performance of this algorithm with some DNA sequences. This test shows that delete-reconstructing can save time when the length of the subsequence deleted is less than 30% of the original sequence, and the insert-reconstructing takes less time with regard to the length of inserted sequence.

• The KIPS Transactions:PartC
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• v.9C no.1
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• pp.9-16
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• 2002

As existing analog video surveillance systems could save and retrieve data only in a limited space within short distance, it had many constraints in developing into various application systems. However, on the back of development of the Internet and computer technologies, digital video surveillance systems can be controlled from a remote location by web browser without space limits. Moreover, data compression and management technologies with Index Search algorithm make it possible to efficiently handling, storing, and retrieving a large amount of data and further motion detection algorithm enhances a recording speed and efficiency for a practical application, that is, a practical remote recordable video surveillance system using our efficient algorithms as mentioned, called WebCam. The WebCam server system can intelligently record and save video images digitized through efficient database management, monitor and control cameras in a remote place through user authentication, and search logs.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.12 no.2
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• pp.35-44
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• 2002

In this paper, an implementation method of RSA exponentiator based on Radix-$2^k$ modular multiplication algorithm is presented and verified. We use Booth receding algorithm to implement Radix-$2^k$ modular multiplication and implement radix-16 modular multiplier using 2K-byte memory and CSA(carry-save adder) array - with two full adder and three half adder delays. For high speed final addition we use a reduced carry generation and propagation scheme called pseudo carry look-ahead adder. Furthermore, the optimum value of the radix is presented through the trade-off between the operating frequency and the throughput for given Silicon technology. We have verified 1,024-bit RSA processor using Altera FPGA EP2K1500E device and Samsung 0.3$\mu\textrm{m}$ technology. In case of the radix-16 modular multiplication algorithm, (n+4+1)/4 clock cycles are needed and the 1,024-bit modular exponentiation is performed in 5.38ms at 50MHz.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.8A
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• pp.847-857
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• 2007

For the implementation of a RFID system, an anti-collision algorithm is required to identify multiple tags within the range of a RFID Reader. A Bit-by-Bit algorithm is defined by Auto ID Class 0. In this paper, we propose a SBBB(Stack Bit-by-Bit) algorithm. The SBBB algorithm save the collision position and makes a query using the saved data. SBBB improve the efficiency of collision resolution. We show the performance of the SBBB algorithm by simulation. The performance of the proposed algorithm is higher than that of BBB algorithm. Especially, the more each tag bit streams are the duplicate, the higher performance is.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10c
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• pp.109-111
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• 2003

최근 무선 네트워킹 장치들이 등장 하면서 제한된 배터리에 의존하는 무선 호스트들의 전력 절감은 중요한 이슈가 되었다. 특히 Ad­Hoc에서 배터리는 제한된 에너지를 제공하기 때문에 무선 호스트에 의해서 소모되어지는 에너지의 양을 감소시키기 위한 기술은 대단히 중요하다. 특히 MAC 과 라우팅 에서 전력 절감을 이루기 위한 논문들이 기존에 발표 되었다. 이 논문에서는 IEEE 802.11 표준의 DCF (Distributed Coordination Function) 에서의 전력 절감 메카니즘을 향상 시킨 논문 이다. DCF를 위한 IEEE 802.11 전력 절감 메카니즘에서는 비콘 간격 이라는 시간으로 나누어지며 또한 이러한 각각의 비콘 간격이 시작될 때 각각의 노드들은 ATIM 창 동안 깨어 있어야 한다. 물론 모든 노드는 같은 시간에 깨어 있기 위해서는 동기화 되는 것이 필요하다. ATIM 창 동안 노드들은 비콘 기간 동안 깨어 있는 상태로 있을 것인지를 결정하기 위해서 control packet을 교환 한다. 이러한 ATIM 창 크기는 각각의 노드들의 전력절감에 상당한 영향을 미친다. 따라서 이 논문은 ATIM 창 크기를 동적으로 증감시켜서 보다 에너지 효율을 발휘 하고자 하는 논문이다.

• Journal of Biomedical Engineering Research
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• v.18 no.4
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• pp.397-407
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• 1997

In this paper, we present a signal analysis environment with visual programming capability, which is called Signal Analysis and Visualization Environment( SAVE). The system allows a user to perform visually programmed analysis of signals and visualize the results. The visualization facility enables the user to compare original signals with processed ones arid also to display signals overlaid synchronously with the events extracted from the signals. The SAVE system has an extensible architecture: each signal processing algorithm is implemented as a separate building block object module, which can be freely added or removed from the SAVE system without any code modification. We describe the overall structure of the SAVE system and the building block objects, which provide the extensibility in collaboration with together. We illustrate some test runs in order to five a taste of how to use and where to use the system.

• Journal of the Korean Institute of Educational Facilities
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• v.19 no.1
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• pp.37-44
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• 2012

This study developed an algorithm to predict the most efficient evacuation protocol in an elementary school that has an irregular type of architectural planning. The assumption of this study takes a stand point that today's elementary schools are designed in unusual and irregular floor type and, therefore, past architect's knowledge regarding efficient evacuation will no longer effective to save lives. In this regard, this study applied an algorithm that is especially designed to find appropriate locations in general in the field of industrial engineering, which has been proven for many decades. Furthermore, this study not only adapted an engineering model but also conversed to examine spatial relationship and added the concept of group evacuation, which will delay the whole evacuation process, in the tested algorithm to make it more architectural. Consequently, this study compared its outcome with an existing elementary school and questioned its effectiveness in evacuation process based on the algorithm.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.10
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• pp.4804-4822
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• 2017

Coverage problem is a research hot spot in directional sensor networks (DSNs). However, the major problem affecting the performance of the current coverage-enhancing strategies is that they just optimize the coverage of networks, but ignore the maximum number of sleep sensors to save more energy. Aiming to find an approximate optimal method that can cover maximum area with minimum number of active sensors, in this paper, a new scheduling algorithm based on learning automata is proposed to enhance area coverage, and shut off redundant sensors as many as possible. To evaluate the performance of the proposed algorithm, several experiments are conducted. Simulation results indicate that the proposed algorithm have effective performance in terms of coverage enhancement and sleeping sensors compared to the existing algorithms.

• Journal of Biomedical Engineering Research
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• v.13 no.4
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• pp.323-330
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• 1992

A Study of Image Compression Algorithm using DCT This paper describes the system that implement a JPEG(Joint Photographic Experts Group) algorithm based on DCT(Discrete Cosine Transform) uslng CCD kameva, Image Grabber, and IBM PC. After cosine transforms the acquisited image, this algorithm quantize and entropy encode the coefficients by JPEG code table. The coefficients are reconstructed by the Huffman decoding, dequantized procedure, and Inverse cosine transform. The results obtained from the impleulented system are as follows. (1) For effcient storage and easy implementation, this system save Image as a PCX formal (2) Thls system get 7:1 compression ratio(3.8 RMSE value) without large distortion. (3) With a low pass filtering, thls system eliminate high frequency components and get 20% enhanced compression ratio. (4) Thls system enhance the reconstructed Image using histogram modeling.

• Journal of Computing Science and Engineering
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• v.8 no.2
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• pp.78-86
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• 2014

Aiming to solve the problems of high memory access and big storage space and long matching time in the regular expression matching of extended finite automaton (XFA), a new regular expression matching algorithm based on high-efficient finite automaton is presented in this paper. The basic idea of the new algorithm is that some extra judging instruments are added at the starting state in order to reduce any unnecessary transition paths as well as to eliminate any unnecessary state transitions. Consequently, the problems of high memory access consumption and big storage space and long matching time during the regular expression matching process of XFA can be efficiently improved. The simulation results convey that our proposed scheme can lower approximately 40% memory access, save about 45% storage space consumption, and reduce about 12% matching time during the same regular expression matching process compared with XFA, but without degrading the matching quality.