• 제목/요약/키워드: Complexity science

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URBAN COMPLEXITY ESTIMATION INDICES BASED ON 3D DISCRETE WAVELET TRANSFORM OF REMOTELY SENSED IMAGERY;THE PRELIMINARY INTERPRETATION WITH LAND COVER MAP

  • Yoo, Hee-Young;Lee, Ki-Won;Kwon, Byung-Doo
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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    • pp.405-409
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    • 2007
  • Each class in remotely sensed imagery has different spectral and spatial characteristics. Natural features have relatively smaller spatial changes than spectral changes. Meanwhile, urban area in which buildings, roads, and cars are included is inclined to face more changes of spatial variation than spectral one. This study aims to propose the new urban complexity index (UCI) based on the 3D DWT computation of remotely sensed imageries considering these characteristics. And then we analyze relation between index and land cover map. The 3DWUCI values are related to class and the indices of urban area are greater than natural area. The proposed UCI could be used to express effectively the standard of urban complexity over a wide area.

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Corporate Meeting Destination Choice: The Effects of Organizational Structure

  • Ariffin, Ahmad Azrni M.;Ishak, Nor Khomar
    • 마케팅과학연구
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    • 제16권4호
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    • pp.75-95
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    • 2006
  • This study attempted to determine the influence of organizational structure on the novelty preference for corporate meeting destination choice. The three dimensions of structure incorporated were formalization, centralization and complexity. A total of 75 corporate meeting planners drawn from public listed services organizations were involved. The main method of data collection was questionnaire survey and multiple regression analysis was employed as the main statistical technique. The results revealed that both formalization and centralization were negatively correlated with novelty preference while complexity was positively correlated. However, only complexity contributed significantly to the prediction of novelty preference for corporate meeting destination choice. The main implication of this study is pertaining to the segmentation and targeting of the corporate meeting market. This study helped in bridging the gap between tourism marketing and organizational research. It also contributed by developing the measurement for novelty preference from the context of experiential marketing.

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펑쳐드 트렐리스 부호화된 위상주파수 변조 (Punctured Trellis Coded Phase Frequency Shift Keying)

  • 홍성권;송왕철;박성경;송명규;강창언
    • 한국전자파학회지:전자파기술
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    • 제6권4호
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    • pp.3-10
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    • 1995
  • In this paper, application of PTCM to 2FSK / 4PSK signals is studied. The generator polynomial of punctured trellis coded 2FSK / 4PSK, metric computation techniques, decoding complexity considerations are provided. Simulation results shows that PTCM of 2FSK / 4PSK archieves equal coding gain in com- parison to Padovani and Wolf's system with less decoding complexity.

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POLYNOMIAL CONVERGENCE OF PREDICTOR-CORRECTOR ALGORITHMS FOR SDLCP BASED ON THE M-Z FAMILY OF DIRECTIONS

  • Chen, Feixiang;Xiang, Ruiyin
    • Journal of applied mathematics & informatics
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    • 제29권5_6호
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    • pp.1285-1293
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    • 2011
  • We establishes the polynomial convergence of a new class of path-following methods for semidefinite linear complementarity problems (SDLCP) whose search directions belong to the class of directions introduced by Monteiro [9]. Namely, we show that the polynomial iteration-complexity bound of the well known algorithms for linear programming, namely the predictor-corrector algorithm of Mizuno and Ye, carry over to the context of SDLCP.

A System Dynamics Approach for Making Group Decision

  • Kwahk Kee-Young;Kim Hee-Woong
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
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    • pp.958-965
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    • 2003
  • The rapidly changing business environment has required cooperation and coorduiation among functional units n organizations which should Involve group decision-making processes Although many group derision-making support tools and methods have provided the collaborative capabilities for organizational members, they often lack features supporting the dynamic complexity issue frequently occurring at group decision-making processes This study proposes system dynamics modeling as a group decision-making support tool to deal with the group derision-making tasks having properties of dynamic complexity in terms of cognitive fit theory.

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An Efficient Sliding Window Algorithm Using Adaptive-Length Guard Window for Turbo Decoders

  • Lim, Hyun-Tack;Kim, Yong-Sang;Cheun, Kyung-Whoon
    • Journal of Communications and Networks
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    • 제14권2호
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    • pp.195-198
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    • 2012
  • An efficient sliding window algorithm employing an adaptive-length guard window for turbo decoders is proposed. The proposed algorithm results in significant complexity reductions, especially for small sliding window lengths where the additional computational complexity required for the guard window is critical.

일반화 공간 변조를 위한 저복잡도 구복호 수신기 (A Low-Complexity Sphere Decoding Algorithm for Generalized Spatial Modulation)

  • 전은탁;윤성민;이재성;우대위;이경천
    • 한국정보통신학회논문지
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    • 제20권1호
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    • pp.30-36
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    • 2016
  • 일반화 공간 변조(Generalized Spatial Modulation)는 다중안테나 시스템의 복잡도를 줄이기 위해 몇 개의 송신 안테나만을 선택하여 신호를 전송하고, 선택된 안테나의 인덱스로 정보를 표현하는 송신 방식이다. 본 연구에서는 일반화 공간 변조의 수신 방식을 고려하며, 구복호(Sphere Decoding) 수신기에서 수신 순서화를 적용하는 것을 제안한다. 기존 구복호 수신기에서 수신 신호에 대한 연산을 최적의 순서로 변형함으로써 탐색 영역을 효과적으로 줄이며 계산량 감소 이득을 얻게 한다. 모의 실험을 통해 일반화 공간 변조 시스템에서 제안한 구복호 수신기와 기존 구복호 수신기를 비교하였으며, 수신 순서화가 적용된 제안 수신기가 동일한 비트오류율 성능을 얻으면서 더 낮은 계산 복잡도를 요구하는 것을 확인하였다.

Computation and Communication Efficient Key Distribution Protocol for Secure Multicast Communication

  • Vijayakumar, P.;Bose, S.;Kannan, A.;Jegatha Deborah, L.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제7권4호
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    • pp.878-894
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    • 2013
  • Secure multimedia multicast applications involve group communications where group membership requires secured dynamic key generation and updating operations. Such operations usually consume high computation time and therefore designing a key distribution protocol with reduced computation time is necessary for multicast applications. In this paper, we propose a new key distribution protocol that focuses on two aspects. The first one aims at the reduction of computation complexity by performing lesser numbers of multiplication operations using a ternary-tree approach during key updating. Moreover, it aims to optimize the number of multiplication operations by using the existing Karatsuba divide and conquer approach for fast multiplication. The second aspect aims at reducing the amount of information communicated to the group members during the update operations in the key content. The proposed algorithm has been evaluated based on computation and communication complexity and a comparative performance analysis of various key distribution protocols is provided. Moreover, it has been observed that the proposed algorithm reduces the computation and communication time significantly.

Conceptual Design Optimization of Tensairity Girder Using Variable Complexity Modeling Method

  • Yin, Shi;Zhu, Ming;Liang, Haoquan;Zhao, Da
    • International Journal of Aeronautical and Space Sciences
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    • 제17권1호
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    • pp.29-36
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    • 2016
  • Tensairity girder is a light weight inflatable fabric structural concept which can be used in road emergency transportation. It uses low pressure air to stabilize compression elements against buckling. With the purpose of obtaining the comprehensive target of minimum deflection and weight under ultimate load, the cross-section and the inner pressure of tensairity girder was optimized in this paper. The Variable Complexity Modeling (VCM) method was used in this paper combining the Kriging approximate method with the Finite Element Analysis (FEA) method, which was implemented by ABAQUS. In the Kriging method, the sample points of the surrogate model were outlined by Design of Experiment (DOE) technique based on Optimal Latin Hypercube. The optimization framework was constructed in iSIGHT with a global optimization method, Multi-Island Genetic Algorithm (MIGA), followed by a local optimization method, Sequential Quadratic Program (SQP). The result of the optimization gives a prominent conceptual design of the tensairity girder, which approves the solution architecture of VCM is feasible and efficient. Furthermore, a useful trend of sensitivity between optimization variables and responses was performed to guide future design. It was proved that the inner pressure is the key parameter to balance the maximum Von Mises stress and deflection on tensairity girder, and the parameters of cross section impact the mass of tensairity girder obviously.