• Title/Summary/Keyword: Searcher

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A Study on an Intermediary System for Searches (정보탐색을 위한 중개시스템에 관한 연구)

  • Lee Hyo Sook
    • Journal of the Korean Society for Library and Information Science
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    • v.17
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    • pp.299-337
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    • 1989
  • In this study, an Intermediary System for Searches has been designed and implemented. This System has some key functions as follows: First, in each stage of a search process, the information related to a definite term could be provided. Second, through displaying semantic categories for terms this system 'helps a searcher in modifying search terms when he fails to retrieve. Third, being consulted, this system could assist a searcher in making a Boolean search statement in terms of search specificity Fourth, to make a final search statement, a searcher could have several rounds of search cycles through displaying related terms, semantic categories, and frames.

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Development and Testing of a New Area Search Model with Partially Overlapping Target and Searcher Patrol Area

  • Kim, Gi-Young;Eagle, James N.;Kang, Sung-Jin
    • Journal of the military operations research society of Korea
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    • v.35 no.1
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    • pp.21-32
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    • 2009
  • In this study, the author uses a MATLAB simulation to develop and test a generalization of the traditional Random Search model which allows both the searcher and target to move and to be in different, but overlapping, areas. Also the best evasion speed for a randomly moving target against a Systematic Search is studied.

Design of high-speed preamble searcher adequate for RACH preamble structure in WCDMA reverse link receiver (RACH 프리앰블 구조에 적합한 WCDMA 역방향 링크 수신기용 고속 프리앰블 탐색기의 설계)

  • 정은선;도주현;이영용;정성현;최형진
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.8A
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    • pp.898-908
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    • 2004
  • In this paper, we propose a high speed preamble searcher feasible for RACH(Random Access Channel) preamble structure in WCDMA reverse link receiver. Unlike IS-95, WCDMA system uses AISMA(Acquisition Indication Sense Multiple Access) process. Because of the time limit between RACH preamble transmission and AI(Acquisition Indicators), and the restriction on the number of RACH signatures assigned to RACH preamble, fast acquisition indication is required for efficient operation. The preamble searcher proposed in this paper is based on 2-antenna system and has adopted FHT algorithm that has the radix-2 16 point FFT structure. The acquisition speed using FHT is 64 times faster than the conventional method that correlates each signature. Based on their fast aquisition scheme, we improved the acquisition performance by calculating the correlation up to the 4096 chips of the total preamble length. The performance is analyzed by using Neyman-pearson method. The proposed algorithm has been applied for the implementation of WCDMA reverse link receiver modem successfully.

Performance Analysis and Design of a WCDMA Mobile Station's Multi-path Searcher for Down-link with Multiple Transmit Antennas (다수의 송신 안테나가 있는 하향 링크에서 W-CDMA 단말기 다중 경로 검색기의 설계 및 성능분석)

  • Kim Young Ju;Won Seung Hwan;Kim En Ki;Lee Insung
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.43 no.1 s.343
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    • pp.95-102
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    • 2006
  • In this paper, we present the performance analysis and design of a multi-path searcher operating over Rayleigh fading channels when multiple transmit antennas are employed in the down-link of W-CDMA system. The simulation results for the receiver operating characteristics (ROC) for 1, 2, and 4 transmit antennas are presented to corroborate the theoretical analyses. We also propose a procedure to find the optimum parameters of double-dwell serial searcher according to the number of the multiple transmit antennas. Our analyses and simulations indicate that post-detection integration is not necessary when the number of transmit antennas is more than two. Finally, we found that increasing transmit diversity order does not necessarily improve the detection performance when the received pilot signal strength is relatively low. Therefore, this gives us a practical criterion on increasing transmit diversity order.

Performance Analysis and Design of a Mobile Station′s Multi-path Searcher for W-CDMA Down-link with Multiple Transmit Antennas (W-CDMA 下向 링크에서 다수의 송신 안테나가 있는 경우 단말기 다중 경로 검색기의 설계 및 성능 분석)

  • Won Seung hwan;Kim Young ju
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.10C
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    • pp.1355-1362
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    • 2004
  • In this paper, we present the performance analysis of a multi-path searcher operating over Rayleigh fading channels when multiple transmit antennas are employed in the down-link of W-CDMA system. The simulation results for the receiver operating characteristics (ROC) for 1, 2, and 4 transmit antennas are presented to corroborate the theoretical analyses. We also propose a procedure to find the optimum parameters of double-dwell serial searcher according to the number of the multiple transmit antennas. Our analyses and simulations indicate that post-detection integration is not necessary when the number of transmit antennas is more than two. Finally, we found that increasing transmit diversity order does not necessarily improve the detection performance when the received pilot signal strength is relatively low. Therefore, this gives us a practical criterion on increasing transmit diversity order.

Mental States in Information Search Process (정보검색과정에서의 정신적 상태)

  • Na, Kyoungsik;Choi, Wontae
    • Journal of Korean Library and Information Science Society
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    • v.48 no.3
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    • pp.281-302
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    • 2017
  • This study examined the differences in a searcher's mental states of a complex information search and retrieval task during information search process between the two groups: participants who were exposed to mental demand manipulation and those not exposed. Data from the experiments and questionnaires were analyzed. Based on qualitative approach and quantitative analyses, the results indicated that the participants exposed to mental demand required more thoughts; addressed negative emotions more often; reduced a searcher's efforts; and interrupted search performance than those not exposed. These results suggest that mental demand contributed to a searcher's perceived thought, emotion, effort, and performance, although these mental states differed in relative contribution of information search process. Significant differences were found between the two groups with respect to the component of mental demand, performance, and frustration of the NASA-TLX subjective cognitive load. These results have implications for search user interface design and information search systems among others.

Codesign of IS-95 based CDMA Searcher (IS-95 기반 CDMA Searcher의 통합설계)

  • 황인기
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.9A
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    • pp.1368-1376
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    • 2000
  • This paper describes the codesign method for IS-95 based CDMA(Code Division Multiple Access). By codesign we mean to design hardware and software simultaneously. Codesign lead to reduction in design time, cost and power consumption. When we partition a system into hardware and software, some modules with longer processing time and larger power consumption are implemented using hardware and the remaining part is implemented using software. In proposed design, we design the synchronous accumulator of CDMA searcher in hardware and the other part in software, The hardware part is designed using VHDL, while software part is designed using GC(Generic C). We simulated and verified the system using COSSAP in SYNOPSYSTM. Experimentation showed the maximum 48.5% speed reduction compared with the design using software only.

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FPGA Implementation of PN Code Searcher with a Shared Architecture for CDMA PCS mobile Station (공유구조를 가지는 CDMA 이동국용 PN 부호 탐색기의 FPGA 구현)

  • 이장희;이성주김재석이문기
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.1109-1112
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    • 1998
  • In this paper, we propose a new architecture of the PN code acquistion system which has some shared blocks in order to reduce the hardware complexity. The proposed system has an energy calculation block which is shared by two active correlators. Our system is designed suitable for IS-95 based CDMA PCS. The new architecture was designed and simulated using VHDL. Also, We implemented it with Altera FPGA, and verified our system. The gate count is about 7,500. Our proposed architecture is also useful for multi-carrier system which uses the multiple searcher.

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Morphological analysis of spoken Korean using Viterbi search (Viterbi 검색 기법을 이용한 한국어 음성 언어의 형태소 분석)

  • 김병창
    • Proceedings of the Acoustical Society of Korea Conference
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    • 1995.06a
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    • pp.200-203
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    • 1995
  • This paper proposes a spoken Korean processing model which is extensible to large vocabulary continuous spoken Korean system. The integration of phoneme level speech recognition with natural language processing can support a sophisticated phonological/morphological analysis. The model consists of a diphone speech recognizer, a viterbi dictionaly searcher and a morpheme connectivity information checker. Two-level hierarchical TDNNs recognize newly defined Korean diphones. The diphone sequences are segmented and converted to the most probable morpheme sequences by the Viterbi dictionary searcher. The morpheme sequency are then examined by the morpheme connectivity information checker and the correct morpheme sequence which has the greatest probability is collected. The experiments show that the morphological analysis for spoken Korean can be achieved for 328 Eojeols with 80.6% success rate.

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