• Title/Summary/Keyword: CSS System

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Throughput and Interference for Cooperative Spectrum Sensing: A Malicious Perspective

  • Gan, Jipeng;Wu, Jun;Zhang, Jia;Chen, Zehao;Chen, Ze
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.11
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    • pp.4224-4243
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    • 2021
  • Cognitive radio (CR) is a feasible intelligent technology and can be used as an effective solution to spectrum scarcity and underutilization. As the key function of CR, cooperative spectrum sensing (CSS) is able to effectively prevent the harmful interference with primary users (PUs) and identify the available spectrum resources by exploiting the spatial diversity of multiple secondary users (SUs). However, the open nature of the cognitive radio networks (CRNs) framework makes CSS face many security threats, such as, the malicious user (MU) launches Byzantine attack to undermine CRNs. For this aim, we make an in-depth analysis of the motive and purpose from the MU's perspective in the interweave CR system, aiming to provide the future guideline for defense strategies. First, we formulate a dynamic Byzantine attack model by analyzing Byzantine behaviors in the process of CSS. On the basis of this, we further make an investigation on the condition of making the fusion center (FC) blind when the fusion rule is unknown for the MU. Moreover, the throughput and interference to the primary network are taken into consideration to evaluate the impact of Byzantine attack on the interweave CR system, and then analyze the optimal strategy of Byzantine attack when the fusion rule is known. Finally, theoretical proofs and simulation results verify the correctness and effectiveness of analyses about the impact of Byzantine attack strategy on the throughput and interference.

Development of the proto type vacuum control system for RAON Accelerator

  • Son, Hyeong-Ju;Lee, Sang-Il;Park, Mi-Jeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.121.1-121.1
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    • 2016
  • RAON은 우라늄과 같은 무거운 이온을 가속시키는 한국형 중이온 가속기로서 현재 양산에 필요한 실험 시설이 구축되고 있다. 이온원을 생성하고 생성된 중이온 빔을 손실 없이 가속시키기 위해서는 빔의 경로인 입사기장치, 가속장치, 실험장치에서 요구하는 최적의 진공 설계가 이루어져야 하며, 이를 제어하기 위해 진공 기기들과의 데이터 통신 및 기기를 보호하기 위한 인터록 로직을 구성하여야 한다. RAON의 진공부 인터록 로직 및 제어 시퀀스는 Programmable Logic Controller (PLC)으로 구성되며, Experimental Physics and Industrial Control System (EPICS) 환경에 통합되어 중앙 제어 시스템에서 관리됨과 동시에 Control System Studio (CSS)를 통해 모니터링 될 것이다. 이를 위해서는 CSS 및 PLC 와 데이터를 송수신할 수 있는 EPICS IOC를 구성하여야 한다. 본 문서에서는 진공 기기들의 정보를 로컬 PLC에서 수집하고, 진공 상태 및 진공 기기들의 작동을 위한 User Interface (UI) 및 EPICS IOC를 구성하는 방법에 대해 논의할 것이다. 진공부 제어 사전 테스트를 위해 프로토 타입 진공 제어 시스템을 구성하였으며, 이를 바탕으로 추후 최적화 된 RAON의 진공 제어 시스템을 구축할 수 있을 것으로 기대한다.

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Class 4 Active RFID Multi-hop Relay System based on IEEE 802.15.4a Low-Rate UWB in Sensor Network

  • Zhang, Hong;Hong, Sung-Hyun;Chang, Kyung-Hi
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.4 no.3
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    • pp.258-272
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    • 2010
  • The low-rate (LR) UWB is a promising technology for the ubiquitous sensor network (USN) due to its extremely low power consumption and simple transceiver implementation. However the limited communication range is a bottleneck for its widespread use. This paper deals with a new frame structure of class 4 active RFID multi-hop relay system based on ISO/IEC 18000-7 standard integrating with IEEE 802.15.4a LR-UWB PHY layer specification, which sets up a connection to USN. As a result of the vital importance of the coverage and throughput in the application of USN, further we analyze the performance of the proposed system considered both impulse radio UWB (IR-UWB) and chirp spread spectrum (CSS). Our simulation results show that the coverage and throughput are remarkably increased.

Design and Implementation of Mobile Tide forecasting System (모바일 조석정보시스템 설계와 구현)

  • Choi, Tae-Chul;Suh, Yeong-Sang;Kim, Eung-Kon;Ceong, Hee-Taek
    • The Journal of the Korea institute of electronic communication sciences
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    • v.3 no.2
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    • pp.101-105
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    • 2008
  • We applied web-standard technologies like XHTML CSS etc. to Mobile Tide Forecasting System. Through mobile hot key(659+hot key), users can connect the system and get conveniently the tide forecasting information in mobile communication environment.

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Effectiveness of Logistics information Systems for RFID - Focusing on CJ GLS Co. Case - (RFID를 이용한 물류정보시스템의 구축효과 -CJ GLS 사례를 중심으로-)

  • Kim, Moon-jung
    • Journal of Distribution Science
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    • v.5 no.2
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    • pp.79-100
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    • 2007
  • CJ GLS Co. builds successfully Warehouse Management Systme (WMS), Customer Service & Support System(CSS), and Delivery Management System using RFID. This study tris to find out the effectiveness in CJ case. RFID, the core technology of Ubiquitous network, is now implied in our policy by the Ministry of Commerce, Industry & Energy. To support the study, examples from Korea and other countries using RFID system were introduced. Examples include the definition and features of RFID and the current applications of RFID. CJ GLS Co. used RFID to build the Integrated Logistics Management System effectively. The study analyzed the background of why to use this system, the goals and objectives of system building and the effectiveness of system building. In conclusion, the future of RFID and SCM was presented.

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Optimal Sensing Time for Maximizing the Throughput of Cognitive Radio Using Superposition Cooperative Spectrum Sensing

  • Vu-Van, Hiep;Koo, Insoo
    • Journal of information and communication convergence engineering
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    • v.13 no.4
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    • pp.221-227
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    • 2015
  • Spectrum sensing plays an essential role in a cognitive radio network, which enables opportunistic access to an underutilized licensed spectrum. In conventional cooperative spectrum sensing (CSS), all cognitive users (CUs) in the network spend the same amount of time on spectrum sensing and waste time in remaining silent when other CUs report their sensing results to the fusion center. This problem is solved by the superposition cooperative spectrum sensing (SPCSS) scheme, where the sensing time of a CU is extended to the reporting time of the other CUs. Subsequently, SPCSS assigns the CUs different sensing times and thus affects both the sensing performance and the throughput of the system. In this paper, we propose an algorithm to determine the optimal sensing time of each CU for SPCSS that maximizes the achieved system throughput. The simulation results prove that the proposed scheme can significantly improve the throughput of the cognitive radio network compared with the conventional CSS.

802.15.4a DBO-CSS의 Coexistence향상을 위한 새로운 Sinusoidal Interference Cancellation 알고리즘

  • Oh, Dae-Gun;Chong, Jong-Wha
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.129-130
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    • 2006
  • As the research of wireless personal area network (WPAN) is more activated, various communication systems operating on 2.4Ghz are being developed. Systems such as Bluetooth, 802.11b, Zigbee and DBO-CSS are operating on 2.4Ghz. In addition to these communication systems, microwave oven resides in 2.4Ghz, so co-existance between each of these communication systems and microwave Oven is considered important factor of system performance. The effect of microwave oven on these communication systems is so critical that these systems are recommended to avoid the impact of microwave oven by allocation of different channel. In this paper, based on the DBO-CSS operating on 2.4Ghz, we propose a new algorithm of reducing the effect of microwave oven to develop robust communication system against microwave oven.

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CELL STATE SPACE ALGORITHM AND NEURAL NETWORK BASED FUZZY LOGIC CONTROLLER DESIGN

  • Aao;Ding, Gen-Ya
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1993.06a
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    • pp.972-974
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    • 1993
  • This paper presents a new method to automatically design fuzzy logic controller(FLC). The main problems of designing FLC are how to optimally and automatically select the control rules and the parameters of membership function (MF). Cell state space algorithms (CSS), differential competitive learning (DCL) and multialyer neural network are combined in this paper to solve the problems. When the dynamical model of a control process is known. CSS can be used to generate a group of optimal input output pairs(X, Y) used by a controller. The(X, Y) then can be used to determine the FLC rules by DCL and to determine the optimal parameters of MF by DCL and to determine the optimal parameters of MF by multilayer neural network trained by BP algorithm.

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Content-based Image Retrieval Using Color and Shape (색상과 형태를 이용한 내용 기반 영상 검색)

  • Ha, Jeong-Yo;Choi, Mi-Young;Choi, Hyung-Il
    • Journal of the Korea Society of Computer and Information
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    • v.13 no.1
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    • pp.117-124
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    • 2008
  • We suggest CBIR(Content Based Image Retrieval) method using color and shape information. Using just one feature information may cause inaccuracy compared with using more than two feature information. Therefore many image retrieval system use many feature informations like color, shape and other features. We use two feature, HSI color information especially Hue value and CSS(Curvature Scale Space) as shape information. We search candidate image form DB which include feature information of many images. When we use two features, we could approach better result.

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Direction-of-Arrival Estimation in Broadband Signal Processing : Rotation of Signal Subspace Approach (광대역 신호 처리에서의 도래각 추정 : Rotation of Signal Subspaces 방법)

  • Kim, Young-Soo
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.7
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    • pp.166-175
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    • 1989
  • In this paper, we present a method which is based on the concept of the rotation of subspaces. This method is highly related to the angle (or distance) between subspaces arising in many applications. An effective procedures is first derived for finding the optimal transformation matrix which rotates one subspace into another as closely as possible in the least squares sense , and then this algorithm is applied to the solution to general direction-of-arrival estimation problem of multiple broadband plane waves which may be a mixture of incoherent, partially coherent or coherent. In this typical application, the rotation of signal subspaces (ROSS) algorithm is effectively developed to achieve the high performance in the active systems for the case in which the noise field remains invariant with the measurement of the array spectral density matrix (or data matrix). It is not uncommon to observe this situation in sonar systems. The advantage of this techniques is not to require the preliminary processing and spatial prefiltering which is used in Wang-Kaveh's CSS focusing method. Furthermore, the array's geometry is not restricted. Simulation results are presented to illustrate the high performance achieved with this new approach relative to that obtained with Wang-Kaveh's CSS focusing method for incoherent sources and forward-backward spatial smoothed MUSIC for coherent sources including the signal eigenvector method (SEM).

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