• Title/Summary/Keyword: low power network

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Security Issues on Smart Grid (스마트 그리드 보안 이슈)

  • Hong, Sunghyuck
    • Journal of Digital Convergence
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    • v.11 no.4
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    • pp.279-284
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    • 2013
  • Improve the global environment for low carbon emissions and green energy, and the growing interest in IT technology, combined with the existing power grid to achieve this, to achieve more efficient and environment-friendly smart grid smart grid projects around the world actively being deployed. A smart grid is expected to be a modernization of the legacy electricity network. Therefore, this research provides a secure smart grid model so that it provides better monitoring, protecting and optimizing automatically to operation of the interconnected elements.

Audio Data Transmission Based on The Wavelet Transform for ZigBee Applications (ZigBee 응용을 위한 웨이블릿변환 기반 오디오 데이터 전송)

  • Chen, Zhenxing;Choi, Eun Chang;Huh, Jae Doo;Kang, Seog Geun
    • IEMEK Journal of Embedded Systems and Applications
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    • v.2 no.1
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    • pp.31-42
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    • 2007
  • A transform coding scheme for the transmission of audio data in ZigBee based wireless personal area networks (WPAN) is presented in this paper. Here, wavelet transform is exploited to encode the features of audio data included mainly in the low frequency region. As a result, it is confirmed that the presented scheme recovers the original audio signals much accurately while it transmits the binary data compressed as 37.5% of the entire data generated without coding scheme. Especially, the mean-squared error between the recovered and original audio data approaches $10^{-4}$ when the signal-to-noise power ratio is sufficiently high. Hence, the presented coding scheme which exploits the wavelet transform is possibly applied for high-quality audio data transmission services in a small-scale sensor network based on ZigBee. Such a result is considered to be applicable as a basic material to update the technical specifications and develop the applications of ZigBee in WPANs.

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An Energy Efficient Routing Algorithm based on Center of Local Clustering in Wireless Sensor Networks (무선센서 네트워크에서의 지역-중앙 클러스터 라우팅 방법)

  • He, Jin Ming;Rhee, Chung-Sei
    • Convergence Security Journal
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    • v.14 no.2
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    • pp.43-50
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    • 2014
  • Recently, lot of researches for the multi-level protocol have been done to balance the sensor node energy consumption of WSN and improve the node efficiency to extend the life of the entire network. Especially in multi-hop protocol, a variety of models have been proposed to improve energy efficiency and apply it to WSN protocol. In this paper, we analyze LEACH algorithm and propose new method based on center of local clustering routing algorithm in wireless sensor networks. We also perform NS-2 simulation to show the performance of our model.

Modified TCP with Post-Checksum Field and Limited Error Control Algorithm for Memory-limited Tiny Sensor Node (메모리 크기 제약이 있는 센서 노드에서의 포스트 체크섬과 제한된 오류제어 알고리즘 연구)

  • Oh, Jong-Taek
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.4
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    • pp.141-145
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    • 2012
  • In a Ubiquitous sensor network environment, the sensor node is in general small and low price, and operating with power limited battery. The reliable TCP/IP protocol is used for transmitting sensed data from the sensor node. A new method was proposed in order to overcome the limitation of small embedded memory, but it is difficult to use for the case of frame error. In this paper, a new algorithm is proposed to manage the receiving frame error or loss, and it is appropriate to the sensor network to send sensed data periodically.

Research on Efficient Applicability Through Review on Standard for Selection of Construction Method for Railway Underground Crossing Transit (철도지하횡단 통과 공법 선정기준에 관한 검토를 통해 효율적인 적용성에 대한 연구)

  • Hwang, Young-Ho;Shon, Jung-Chul;Baek, Jong-Myeong
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.595-600
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    • 2007
  • Greater expansion and more frequent operation of the railroad transportation system anticipated due to its characteristics including low cost, safety and mass transportation. Recently, effects on the railway structures due to expansion of newly constructed road, construction of subway, city gas pipeline, communication network, electric power network and construction of other railway underground crossing in accordance with urban planning and organization has influenced safe operation of trains. Accordingly, standard for selection of construction method that will enable construction of more economical and rational subway underground crossing structures by preventing problems occurring at the time of above construction works and accidents in safe operation of trains due to construction in advance is definitively necessary. Although there are numerous construction methods that can be applied at the time of construction of railway underground crossing, there are much difficulties in selection of appropriate construction method that considers characteristics of each construction method on non-excavation type construction method, train operation plan of number of operational routes and on-site circumstances. Therefore, this research aims to present rational standard for selection of construction method for such, and standard for slowdown speed and interception of train when passing the areas of slowdown in sectors under construction.

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An Optimal Installation Strategy for Allocating Energy Storage Systems and Probabilistic-Based Distributed Generation in Active Distribution Networks

  • Sattarpour, Tohid;Tousi, Behrouz
    • Transactions on Electrical and Electronic Materials
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    • v.18 no.6
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    • pp.350-358
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    • 2017
  • Recently, owing to increased interest in low-carbon energy supplies, renewable energy sources such as photovoltaics and wind turbines in distribution networks have received considerable attention for generating clean and unlimited energy. The presence of energy storage systems (ESSs) in the promising field of active distribution networks (ADNs) would have direct impact on power system problems such as encountered in probabilistic distributed generation (DG) model studies. Hence, the optimal procedure is offered herein, in which the simultaneous placement of an ESS, photovoltaic-based DG, and wind turbine-based DG in an ADN is taken into account. The main goal of this paper is to maximize the net present value of the loss reduction benefit by considering the price of electricity for each load state. The proposed framework consists of a scenario tree method for covering the existing uncertainties in the distribution network's load demand as well as DG. The collected results verify the considerable effect of concurrent installation of probabilistic DG models and an ESS in defining the optimum site of DG and the ESS and they demonstrate that the optimum operation of an ESS in the ADN is consequently related to the highest value of the loss reduction benefit in long-term planning as well. The results obtained are encouraging.

Behavior Learning of Swarm Robot System using Bluetooth Network

  • Seo, Sang-Wook;Yang, Hyun-Chang;Sim, Kwee-Bo
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.9 no.1
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    • pp.10-15
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    • 2009
  • With the development of techniques, robots are getting smaller, and the number of robots needed for application is greater and greater. How to coordinate large number of autonomous robots through local interactions has becoming an important research issue in robot community. Swarm Robot Systems (SRS) is a system that independent autonomous robots in the restricted environments infer their status from pre-assigned conditions and operate their jobs through the cooperation with each other. In the SRS, a robot contains sensor part to percept the situation around them, communication part to exchange information, and actuator part to do a work. Especially, in order to cooperate with other robots, communicating with other robots is one of the essential elements. Because Bluetooth has many advantages such as low power consumption, small size module package, and various standard protocols, it is rated as one of the efficient communicating technologies which can apply to small-sized robot system. In this paper, we will develop Bluetooth communicating system for autonomous robots. And we will discuss how to construct and what kind of procedure to develop the communicating system for group behavior of the SRS under intelligent space.

Bluetooth Network for Group Behavior of Multi-Agent Robotic System

  • Seo, Sang-Wook;Ko, Kwang-Eun;Hwang, Se-Hee;Jang, In-Hun;Sim, Kwee-Bo
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.7 no.1
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    • pp.17-21
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    • 2007
  • Multi-Agent Robotic System (MARS) is a system that independent autonomous robots in the restricted environments infer their status from pre-assigned conditions and operate their jobs through the cooperation with each other. In the MARS, a robot contains sensor part to percept the situation around themselves, communication part to exchange information, and actuator part to do given work. Especially, in order to cooperate with other robots, communicating with other robots is one of the essential elements. Because Bluetooth has many advantages such as low power consumption, small size module package, and various standard protocols, Bluetooth is rated as one of the efficient communicating technologies which can apply to small-sized robot system. In this paper, we will develop Bluetooth communicating system for autonomous robots. For the purpose, the communication system must have several features-separated module, flexible interface. We will discuss how to construct and what kind of procedure to develop the communicating system.

A Lightweight Integrity Authentication Scheme based on Reversible Watermark for Wireless Body Area Networks

  • Liu, Xiyao;Ge, Yu;Zhu, Yuesheng;Wu, Dajun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.12
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    • pp.4643-4660
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    • 2014
  • Integrity authentication of biometric data in Wireless Body Area Network (WBAN) is a critical issue because the sensitive data transmitted over broadcast wireless channels could be attacked easily. However, traditional cryptograph-based integrity authentication schemes are not suitable for WBAN as they consume much computational resource on the sensor nodes with limited memory, computational capability and power. To address this problem, a novel lightweight integrity authentication scheme based on reversible watermark is proposed for WBAN and implemented on a TinyOS-based WBAN test bed in this paper. In the proposed scheme, the data is divided into groups with a fixed size to improve grouping efficiency; the histogram shifting technique is adopted to avoid possible underflow or overflow; local maps are generated to restore the shifted data; and the watermarks are generated and embedded in a chaining way for integrity authentication. Our analytic and experimental results demonstrate that the integrity of biometric data can be reliably authenticated with low cost, and the data can be entirely recovered for healthcare applications by using our proposed scheme.

Multipath Searcher for W-CDMA System (W-CDMA 시스템을 위한 다중경노 탐색기)

  • 원석호;김환우
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.6B
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    • pp.601-609
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    • 2002
  • In multi-path wireless channels with time-variant delay profile, a mobile station measures the received signal strength and report it to network which performs network control function such as handover. In order to improve the maximum ratio combining (MRC) gain, it also should search the strongest signal paths and measure their time offsets fast and exactly. This paper proposes some methods of fast and exactly measuring the multi-path signal strength and time offset. Since the W-CDMA system adopts antenna diversity technique for the next generation high speed packet access (HSDPA) service, we derive the optimum design parameter values for the proposed methods through computer simulations under the HSDPA conditions o( low speed of mobile, of no power control, and of multi-path wireless environment with transmit and receive antenna diversity. Finally, we prove the validity of the proposed methods by showing the improvement of the bit error rate (BER) performance.