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Tuple Pruning Using Bloom Filter for Packet Classification (패킷 분류를 위한 블룸 필터 이용 튜플 제거 알고리즘)

  • Kim, So-Yeon;Lim, Hye-Sook
    • Journal of KIISE:Information Networking
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    • v.37 no.3
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    • pp.175-186
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    • 2010
  • Due to the emergence of new application programs and the fast growth of Internet users, Internet routers are required to provide the quality of services according to the class of input packets, which is identified by wire-speed packet classification. For a pre-defined rule set, by performing multi-dimensional search using various header fields of an input packet, packet classification determines the highest priority rule matching to the input packet. Efficient packet classification algorithms have been widely studied. Tuple pruning algorithm provides fast classification performance using hash-based search against the candidate tuples that may include matching rules. Bloom filter is an efficient data structure composed of a bit vector which represents the membership information of each element included in a given set. It is used as a pre-filter determining whether a specific input is a member of a set or not. This paper proposes new tuple pruning algorithms using Bloom filters, which effectively remove unnecessary tuples which do not include matching rules. Using the database known to be similar to actual rule sets used in Internet routers, simulation results show that the proposed tuple pruning algorithm provides faster packet classification as well as consumes smaller memory amount compared with the previous tuple pruning algorithm.

A Case Study on the Service Programs at the Presidential Library and Museum (대통령 기록관의 서비스 프로그램 사례 연구)

  • Jo, Min-Ji
    • Journal of Korean Society of Archives and Records Management
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    • v.6 no.2
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    • pp.157-184
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    • 2006
  • Presidential records which have produced during a presidency as a national center are the evidence of the presidency and main historical records. We have the responsibility to establish fundamental systems to produce such main historical records and to manage such main historical records which could help people and history to judge the presidency based upon the evidence of their activities. The historical appraisal could be achieved not by memory but by evidence. A draft of a proposed law on the management of presidential records which includes the establishment of presidential libraries for the presidential records Mecca is being moored at the National Assembly now. The presidential library is to be considered as a multi-functional national institution which is carrying out the role as an Archives, Museums and Center for the education. In addition, it is imperative for a presidential library to provide user-oriented services to enrich the usability and the value of records, recognizing the change of administration paradigm from a supplier-oriented system to a customer-oriented system. This dissertation, in order to develop presidential library service programs focusing on customers rather than the convenience of administration, reviewed programs of the U.S. presidential libraries as a developed case and proposes guidelines and applicable samples for the development of the Korean presidential library service programs.

A Comparative Content Analysis of Newspapers in Three Countries-Korea, China and Japan-on the 60th Anniversary of the Historical Event, 8.15 Independence Day (한.중.일 3국 신문의 8.15 보도 비교 분석)

  • Seo, Ra-Mi;Jung, Jae-Min
    • Korean journal of communication and information
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    • v.37
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    • pp.237-269
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    • 2007
  • This study examined how newspapers covered the 60th anniversary of the historical event, 8 15 Independence Day. Specifically, five newspapers from three countries were content-analyzed to see differences, if any, based on country level and political ideology of the newspaper. The findings showed that Japanese newspapers yielded less amount of coverage than those of Korea and China. The newspapers of Korea and China used straight news format, while Japanese newspapers used opinion news format. In terms of information source, Korean newspapers and Chinese newspapers mainly relied on the information from the government, while Japanese newspapers took the information from citizen. The difference also revealed that Korean newspapers focused on domestic situation frame and the other countries more emphasized past memory of the War times. Consequently, the three countries showed clearly different perspectives on the same historical event. These distinctions were caused from national interest rather than political ideology of the newspaper.

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Fast Motion Estimation for Variable Motion Block Size in H.264 Standard (H.264 표준의 가변 움직임 블록을 위한 고속 움직임 탐색 기법)

  • 최웅일;전병우
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.6
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    • pp.209-220
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    • 2004
  • The main feature of H.264 standard against conventional video standards is the high coding efficiency and the network friendliness. In spite of these outstanding features, it is not easy to implement H.264 codec as a real-time system due to its high requirement of memory bandwidth and intensive computation. Although the variable block size motion compensation using multiple reference frames is one of the key coding tools to bring about its main performance gain, it demands substantial computational complexity due to SAD (Sum of Absolute Difference) calculation among all possible combinations of coding modes to find the best motion vector. For speedup of motion estimation process, therefore, this paper proposes fast algorithms for both integer-pel and fractional-pel motion search. Since many conventional fast integer-pel motion estimation algorithms are not suitable for H.264 having variable motion block sizes, we propose the motion field adaptive search using the hierarchical block structure based on the diamond search applicable to variable motion block sizes. Besides, we also propose fast fractional-pel motion search using small diamond search centered by predictive motion vector based on statistical characteristic of motion vector.

Performance Evaluation of the GPU Architecture Executing Parallel Applications (병렬 응용프로그램 실행 시 GPU 구조에 따른 성능 분석)

  • Choi, Hong-Jun;Kim, Cheol-Hong
    • The Journal of the Korea Contents Association
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    • v.12 no.5
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    • pp.10-21
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    • 2012
  • The role of GPU has evolved from graphics-specific processing to general-purpose processing with the development of unified shader core architecture. Especially, execution methods for general-purpose parallel applications using GPU have been researched intensively, since the parallel hardware architecture can be utilized efficiently when the parallel applications are executed. However, current GPU architecture has limitations in executing general-purpose parallel applications, since the GPU is not specialized for general-purpose computing yet. To improve the GPU performance when general-purpose parallel applications are executed, the GPU architecture should be evolved. In this work, we analyze the GPU performance according to the architecture varying the number of cores and clock frequency. Our simulation results show that the GPU performance improves by up to 125.8% and 16.2% as the number of cores increases and the clock frequency increases, respectively. However, note that the improvement of the GPU performance is saturated even though the number of cores increases and the clock frequency increases continuously, since the data cannot be provided to the GPU due to the limit of memory bandwidth. Consequently, to accomplish high performance effectiveness on GPU, computational resources must be more suitably considered.

A study on Etch Characteristics of {Y-2}{O_3}$ Thin Films in Inductively Coupled Plasma (유도 결합 플라즈마를 이용한 {Y-2}{O_3}$ 박막의 식각 특성 연구)

  • Kim, Yeong-Chan;Kim, Chang-Il
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.38 no.9
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    • pp.611-615
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    • 2001
  • Y$_2$O$_3$ thin films have been proposed as a buffering insulator of metal/ferroelectric/insulator/semiconductor field effect transistor(MFISFET)-type ferroelectric random access memory (FRAM). In this study, $Y_2$O$_3$ thin films were etched with inductively coupled plasma(ICP). The etch rates of $Y_2$O$_3$ and YMnO$_3$, and the selectivity of $Y_2$O$_3$ to YMnO$_3$ were investigated by varying Cl$_2$/(Cl$_2$+Ar) gas mixing ratio. The maximum etch rate of $Y_2$O$_3$, and the selectivity of $Y_2$O$_3$ to YMnO$_3$ were 302$\AA$/min, and 2.4 at Cl$_2$/(Cl$_2$+Ar) gas mixing ratio of 0.2 respectively. Optical emission spectroscopy(OES) was used to understand the effects of gas combination on the etch rate of $Y_2$O$_3$ thin film. The surface reaction of the etched $Y_2$O$_3$ thin films was investigated by x-ray photoelectron spectroscopy (XPS). XPS analysis confirmed that there was chemical reaction between Y and Cl. This result was confirmed by secondary ion mass spectroscopy(SIMS) analysis.

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Radix-4 Trellis Parallel Architecture and Trace Back Viterbi Decoder with Backward State Transition Control (Radix-4 트렐리스 병렬구조 및 역방향 상태천이의 제어에 의한 역추적 비터비 디코더)

  • 정차근
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.40 no.5
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    • pp.397-409
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    • 2003
  • This paper describes an implementation of radix-4 trellis parallel architecture and backward state transition control trace back Viterbi decoder, and presents the application results to high speed wireless LAN. The radix-4 parallelized architecture Vietrbi decoder can not only improve the throughput with simple structure, but also have small processing delay time and overhead circuit compared to M-step trellis architecture one. Based on these features, this paper addresses a novel Viterbi decoder which is composed of branch metric computation, architecture of ACS and trace back decoding by sequential control of backward state transition for the implementation of radix-4 trellis parallelized structure. With the proposed architecture, the decoding of variable code rate due to puncturing the base code can easily be implemented by the unified Viterbi decoder. Moreover, any additional circuit and/or peripheral control logic are not required in the proposed decoder architecture. The trace back decoding scheme with backward state transition control can carry out the sequential decoding according to ACS cycle clock without additional circuit for survivor memory control. In order to evaluate the usefulness, the proposed method is applied to channel CODEC of the IEEE 802.11a high speed wireless LAN, and HDL coding simulation results are presented.

An Efficient Test Compression Scheme based on LFSR Reseeding (효율적인 LFSR 리시딩 기반의 테스트 압축 기법)

  • Kim, Hong-Sik;Kim, Hyun-Jin;Ahn, Jin-Ho;Kang, Sung-Ho
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.46 no.3
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    • pp.26-31
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    • 2009
  • A new LFSR based test compression scheme is proposed by reducing the maximum number of specified bits in the test cube set, smax, virtually. The performance of a conventional LFSR reseeding scheme highly depends on smax. In this paper, by using different clock frequencies between an LFSR and scan chains, and grouping the scan cells, we could reduce smax virtually. H the clock frequency which is slower than the clock frequency for the scan chain by n times is used for LFSR, successive n scan cells are filled with the same data; such that the number of specified bits can be reduced with an efficient grouping of scan cells. Since the efficiency of the proposed scheme depends on the grouping mechanism, a new graph-based scan cell grouping heuristic has been proposed. The simulation results on the largest ISCAS 89 benchmark circuit show that the proposed scheme requires less memory storage with significantly smaller area overhead compared to the previous test compression schemes.

A Study on the Precedence of the Risk of Problem Features of Senile Dementia Patients (치매노인의 문제특성에 대한 위험순위에 관한 연구)

  • You, Ji-Hye;Lee, Hang-Woon;Eom, Jin-Sup;Park, Soo-Jun;Lee, Bong-Soo;Lee, Jeong-Whan;Tack, Gye-Rae;Chung, Soon-Cheol
    • Science of Emotion and Sensibility
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    • v.10 no.1
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    • pp.79-86
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    • 2007
  • Selected cognitive ability test and survey of basic & problem characteristics were conducted on 110 hospitalized senile dementia patients to extract important problem features. Twenty important problem features were extracted by the factor analysis. In this study, the precedence of the risk of 20 problem features was determined for care of senile dementia patients. Questionnaire was conducted on 32 clinical psychologists who had experienced the diagnosis and treatment of senile dementia patients. Using AHP (Analytic Hierarchy Process), relative risk levels were studied and the precedence of risk was determined by making 20 important problem features in order of the risk. Results of two analyses indicated that during normal daily activities of senile dementia patients the cognitive problem such as memory impairment, judgement disorder and disorientation is the most dangerous risk factor.

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Fabrication of Electrospun PAN/FA Nanocomposites and Their Adsorption Effects for Reducing Volatile Organic Compounds (전기방사에 의한 PAN/FA 나노 복합재의 제조 및 휘발성 유기 화합물에 대한 흡착효과)

  • Ge, Jun Cong;Wang, Zi Jian;Yoon, Sam Ki;Choi, Nag Jung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.6
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    • pp.702-708
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    • 2018
  • Volatile organic compounds (VOCs), as a significant air pollutant, is generated mainly from the burning of fossil fuels, building materials using painting, etc. The inhalation of a certain amount of VOCs can be deleterious to human health, e.g., headaches, nausea and vomiting. In addition, it can also cause memory loss and even increase the rate of leukemia. Therefore, as one of the methods for reducing VOCs in air, polyacrylonitrile/fly ash (PAN/FA) composite nanofibrous membranes were fabricated by electrospinning. To observe their VOCs adsorption capacity, the morphological structure of PAN/FA nanofibrous mats was investigated by field emission scanning electron microscopy (FE-SEM), and the VOCs (chloroform, benzene, toluene, and xylene) adsorption capacity of PAN/FA membranes were tested by gas chromatography/mass spectrometry (GC/MS). The results indicated that the PAN nanofiber containing 40 wt. % FA powder had the smallest fiber diameter of 283 nm; they also showed the highest VOCs adsorption capacity compared to other composite membranes.