WorldWideScience

Sample records for wireless local positioning

  1. A scalable global positioning system-free localization scheme for underwater wireless sensor networks

    KAUST Repository

    Mohammed, A.M.

    2013-05-07

    Seaweb is an acoustic communication technology that enables communication between sensor nodes. Seaweb technology utilizes the commercially available telesonar modems that has developed link and network layer firmware to provide a robust undersea communication capability. Seaweb interconnects the underwater nodes through digital signal processing-based modem by using acoustic links between the neighboring sensors. In this paper, we design and investigate a global positioning system-free passive localization protocol by integrating the innovations of levelling and localization with the Seaweb technology. This protocol uses the range data and planar trigonometry principles to estimate the positions of the underwater sensor nodes. Moreover, for precise localization, we consider more realistic conditions namely, (a) small displacement of sensor nodes due to watch circles and (b) deployment of sensor nodes over non-uniform water surface. Once the nodes are localized, we divide the whole network field into circular levels and sectors to minimize the traffic complexity and thereby increases the lifetime of the sensor nodes in the network field. We then form the mesh network inside each of the sectors that increases the reliability. The algorithm is designed in such a way that it overcomes the ambiguous nodes errata and reflected paths and therefore makes the algorithm more robust. The synthetic network geometries are so designed which can evaluate the algorithm in the presence of perfect or imperfect ranges or in case of incomplete data. A comparative study is made with the existing algorithms which proves the efficiency of our newly proposed algorithm. 2013 Mohammed et al.

  2. Secure positioning in wireless networks

    DEFF Research Database (Denmark)

    Capkun, Srdjan; Hubaux, Jean-Pierre

    2006-01-01

    So far, the problem of positioning in wireless networks has been studied mainly in a non-adversarial settings. In this work, we analyze the resistance of positioning techniques to position and distance spoofing attacks. We propose a mechanism for secure positioning of wireless devices, that we call...... Verifiable Multilateration. We then show how this mechanism can be used to secure positioning in sensor networks. We analyze our system through simulations....

  3. Method and system for localization in a wireless network

    NARCIS (Netherlands)

    Havinga, Paul J.M.; Dil, B.J.

    2011-01-01

    The present invention relates to a method and system for localization in wireless networks. More in particular, the present invention is relates to Received Signal Strength (RSS) based localization in wireless networks, such as localization based on Radio Interferometric Positioning (RIP). Unlike

  4. Principles of wireless access and localization

    CERN Document Server

    Pahlavan, Kaveh

    2013-01-01

    A comprehensive, encompassing and accessible text examining a wide range of key Wireless Networking and Localization technologies This book provides a unified treatment of issues related to all wireless access and wireless localization techniques.  The book reflects principles of design and deployment of infrastructure for wireless access and localization for wide, local, and personal networking.   Description of wireless access methods includes design and deployment of traditional TDMA and CDMA technologies and emerging Long Term Evolution (LTE) techniques for wide area cellular networks, the

  5. Censored cooperative positioning for dense wireless networks

    NARCIS (Netherlands)

    Das, Kallol; Wymeersch, Henk

    Cooperative positioning is an emerging topic in wireless sensor networks and navigation. It can improve the positioning accuracy and coverage in GPS-challenged conditions such as inside tunnels, in urban canyons, and indoors. Different algorithms have been proposed relying on iteratively exchanging

  6. Recent Advances in Wireless Indoor Localization Techniques and System

    Directory of Open Access Journals (Sweden)

    Zahid Farid

    2013-01-01

    Full Text Available The advances in localization based technologies and the increasing importance of ubiquitous computing and context-dependent information have led to a growing business interest in location-based applications and services. Today, most application requirements are locating or real-time tracking of physical belongings inside buildings accurately; thus, the demand for indoor localization services has become a key prerequisite in some markets. Moreover, indoor localization technologies address the inadequacy of global positioning system inside a closed environment, like buildings. Based on this, though, this paper aims to provide the reader with a review of the recent advances in wireless indoor localization techniques and system to deliver a better understanding of state-of-the-art technologies and motivate new research efforts in this promising field. For this purpose, existing wireless localization position system and location estimation schemes are reviewed, as we also compare the related techniques and systems along with a conclusion and future trends.

  7. A forensic readiness model for Wireless Local Area Networks

    CSIR Research Space (South Africa)

    Ngobeni, S

    2010-01-01

    Full Text Available Over the past decade, wireless mobile communications technology based on IEEE 802.11 wireless local area networks (WLANs) has been adopted worldwide on a massive scale. However, as the number of wireless users has soared, so has the possibility...

  8. Wireless Local Area Network (WLAN) Vulnerability Assessment and Security

    National Research Council Canada - National Science Library

    Kessel, Adam; Goodwin, Shane

    2005-01-01

    The proliferation of wireless computer equipment and Local Area Networks (LANs) create an increasingly common and growing threat to Marine Corps Network infrastructure and communication security (COMSEC...

  9. Wireless local area network. A new technology of network

    International Nuclear Information System (INIS)

    Wu Yunjun; Zhao Zongtao

    2003-01-01

    This paper introduces Wireless Local Area Network (WLAN), including the concept, history, characters and the foreground of its development, it also narrates in detail the several key techniques used to implement IEEE802.11 WLAN, and ideas on key technology of future progress in wireless LAN field have also been presented. (authors)

  10. Localization Algorithms of Underwater Wireless Sensor Networks: A Survey

    Science.gov (United States)

    Han, Guangjie; Jiang, Jinfang; Shu, Lei; Xu, Yongjun; Wang, Feng

    2012-01-01

    In Underwater Wireless Sensor Networks (UWSNs), localization is one of most important technologies since it plays a critical role in many applications. Motivated by widespread adoption of localization, in this paper, we present a comprehensive survey of localization algorithms. First, we classify localization algorithms into three categories based on sensor nodes’ mobility: stationary localization algorithms, mobile localization algorithms and hybrid localization algorithms. Moreover, we compare the localization algorithms in detail and analyze future research directions of localization algorithms in UWSNs. PMID:22438752

  11. Free positioning for inductive wireless power system

    NARCIS (Netherlands)

    Waffenschmidt, E.

    2012-01-01

    In inductive wireless power transmission system a lateral displacement of the receiver coil to the transmitter coil leads to a change ofthe coupling factor and thus an unwanted variation of the power transfer. Here, an algorithm to determine the turn distribution to achieve homogeneous coupling

  12. Introduction to Wireless Localization With iPhone SDK Examples

    CERN Document Server

    Chan, Eddie C L

    2012-01-01

    This book provides a comprehensive overview of the entire landscape of both outdoor and indoor wireless positioning, and guides the reader step by step in the implementation of wireless positioning applications on the iPhone. Explanations of fundamental positioning techniques are given throughout the text, along with many programming examples, providing the reader with an independent, practical, and enjoyable learning of the material while gaining a real feel for the subject.  Provides an accessible introduction to positioning technologies such as Global Positioning System and Wi-Fi posi

  13. Data security in wireless local area network

    International Nuclear Information System (INIS)

    Kishk, A.M.A

    2010-01-01

    The ever increasing demand for performance and data security improvement in wireless local area network (W LAN) has motivated increasing the difficulties to crack the system by man-in -the middle attacks. There are two primary and main objectives of this thesis to enhance data security in WLAN. The first objective is the enhancement of identities-exchange and key-exchange during authentication process. The second objective is the investigation of a proposed symmetrical encryption algorithm based on key-updating to enhance the performance of data-security in WLAN. The current asymmetrical encryption algorithms are used to authenticate the devices in WLAN to each other. They are used to exchange the identities and the keys in a secret channel during the authentication process. This thesis investigates the problems of identities- exchange. The enhancement of the identities-exchange and key-exchange stages during the authentication process has been suggested and studied in the thesis to solve the drawbacks of the traditional asymmetrical encryption algorithms.Next the investigation of a proposed symmetrical encryption to encrypt the data during the data exchange process gives a new approach to increase the difficulties to the man in the middle attacks to crack the system.The key updating with each packet is the new approach to solve the problem of the fixed key used to encrypt / decrypt the data with all packets in WLAN.A Comparative study between the proposed symmetrical encryption algorithms and the other algorithms is presented in the thesis. Proposed symmetrical encryption algorithm is applied on a text, voice, and image messages as practical applications of the proposed symmetrical encryption algorithm. Finally, the man-in-the middle attacks can broadcast noise signals in WLAN channels to prevent the data to reach correctly to the end-user. The quality of the received image is measured for the proposed and the traditional symmetrical encryption algorithms to

  14. Event localization in underwater wireless sensor networks using Monitoring Courses

    KAUST Repository

    Debont, Matthew John Robert

    2012-08-01

    We propose m-courses (Monitoring Courses), a novel solution to localize events in an underwater wireless sensor network. These networks consists of surface gateways and relay nodes. GPS can localize the position of surface gateways which can then distribute their locations through the network using acoustic modems. Relay nodes are deployed to remain static, but these untethered nodes may drift due to water currents, resulting in disruption of communication links. We develop a novel underwater alarm system using a cyclic graph model. In the event of link failure, a series of alarm packets are broadcast in the network. These alarms are then captured by the underwater m-courses, which can also be used to assure network connectivity and identify node failures. M-courses also allow the network to localize events and identify network issues locally before forwarding results upwards to a Surface Gateway node. This reduces communication overhead and allows for efficient management of nodes in a mobile network. Our results show that m-course routing reduces the number of sends required to report an event to a Surface Gateway by up to 80% when compared to a naïve routing implementation.

  15. Semantic wireless localization of WiFi terminals in smart buildings

    Science.gov (United States)

    Ahmadi, H.; Polo, A.; Moriyama, T.; Salucci, M.; Viani, F.

    2016-06-01

    The wireless localization of mobile terminals in indoor scenarios by means of a semantic interpretation of the environment is addressed in this work. A training-less approach based on the real-time calibration of a simple path loss model is proposed which combines (i) the received signal strength information measured by the wireless terminal and (ii) the topological features of the localization domain. A customized evolutionary optimization technique has been designed to estimate the optimal target position that fits the complex wireless indoor propagation and the semantic target-environment relation, as well. The proposed approach is experimentally validated in a real building area where the available WiFi network is opportunistically exploited for data collection. The presented results point out a reduction of the localization error obtained with the introduction of a very simple semantic interpretation of the considered scenario.

  16. Localization and Communication for UWB-based Wireless Sensor Networks

    NARCIS (Netherlands)

    Wang, Y.

    2011-01-01

    The great demand for location-aware wireless sensor networks (WSNs) motivates the research in this thesis. The unique characteristics of WSNs impose numerous challenges on localization and communication. In this thesis, we handle some key challenges and provide affordable solutions. Impulse radio

  17. Research on Secure Localization Model Based on Trust Valuation in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Peng Li

    2017-01-01

    Full Text Available Secure localization has become very important in wireless sensor networks. However, the conventional secure localization algorithms used in wireless sensor networks cannot deal with internal attacks and cannot identify malicious nodes. In this paper, a localization based on trust valuation, which can overcome a various attack types, such as spoofing attacks and Sybil attacks, is presented. The trust valuation is obtained via selection of the property set, which includes estimated distance, localization performance, position information of beacon nodes, and transmission time, and discussion of the threshold in the property set. In addition, the robustness of the proposed model is verified by analysis of attack intensity, localization error, and trust relationship for three typical scenes. The experimental results have shown that the proposed model is superior to the traditional secure localization models in terms of malicious nodes identification and performance improvement.

  18. Underwater Optical Wireless Communications, Networking, and Localization: A Survey

    KAUST Repository

    Saeed, Nasir

    2018-02-28

    Underwater wireless communications can be carried out through acoustic, radio frequency (RF), and optical waves. Compared to its bandwidth limited acoustic and RF counterparts, underwater optical wireless communications (UOWCs) can support higher data rates at low latency levels. However, severe aquatic channel conditions (e.g., absorption, scattering, turbulence, etc.) pose great challenges for UOWCs and significantly reduce the attainable communication ranges, which necessitates efficient networking and localization solutions. Therefore, we provide a comprehensive survey on the challenges, advances, and prospects of underwater optical wireless networks (UOWNs) from a layer by layer perspective which includes: 1) Potential network architectures; 2) Physical layer issues including propagation characteristics, channel modeling, and modulation techniques 3) Data link layer problems covering link configurations, link budgets, performance metrics, and multiple access schemes; 4) Network layer topics containing relaying techniques and potential routing algorithms; 5) Transport layer subjects such as connectivity, reliability, flow and congestion control; 6) Application layer goals and state-of-the-art UOWN applications, and 7) Localization and its impacts on UOWN layers. Finally, we outline the open research challenges and point out the future directions for underwater optical wireless communications, networking, and localization research.

  19. Improved Grid-Scan Localization Algorithm for Wireless Sensor Networks

    OpenAIRE

    Nallanthighal, Raghava Srinivasa; Chinta, Veeranjaneyulu

    2014-01-01

    Localization is a fundamental and crucial service for various applications in wireless sensor networks (WSNs). In this paper an improved grid-scan localization algorithm has been proposed. In the proposed algorithm, information about 1-hop, 2-hop, and farther neighboring anchors has been collected that estimates the region using 1-hop anchors. Then, this estimated region is divided into a grid array, finding valid grids using 1-hop and 2-hop anchors information. In addition to that the farthe...

  20. Research on Algorithm of Three-Dimensional Wireless Sensor Networks Node Localization

    Directory of Open Access Journals (Sweden)

    Jiang Minlan

    2016-01-01

    Full Text Available This paper proposes a three-dimensional wireless sensor networks node localization algorithm based on multidimensional scaling anchor nodes, which is used to realize the absolute positioning of unknown nodes by using the distance between the anchor nodes and the nodes. The core of the proposed localization algorithm is a kind of repeated optimization method based on anchor nodes which is derived from STRESS formula. The algorithm employs the Tunneling Method to solve the local minimum problem in repeated optimization, which improves the accuracy of the optimization results. The simulation results validate the effectiveness of the algorithm. Random distribution of three-dimensional wireless sensor network nodes can be accurately positioned. The results satisfy the high precision and stability requirements in three-dimensional space node location.

  1. Indoor Positioning System Using Depth Maps and Wireless Networks

    Directory of Open Access Journals (Sweden)

    Jaime Duque Domingo

    2016-01-01

    Full Text Available This work presents a new Indoor Positioning System (IPS based on the combination of WiFi Positioning System (WPS and depth maps, for estimating the location of people. The combination of both technologies improves the efficiency of existing methods, based uniquely on wireless positioning techniques. While other positioning systems force users to wear special devices, the system proposed in this paper just requires the use of smartphones, besides the installation of RGB-D sensors in the sensing area. Furthermore, the system is not intrusive, being not necessary to know people’s identity. The paper exposes the method developed for putting together and exploiting both types of sensory information with positioning purposes: the measurements of the level of the signal received from different access points (APs of the wireless network and the depth maps provided by the RGB-D cameras. The obtained results show a significant improvement in terms of positioning with respect to common WiFi-based systems.

  2. Design of a Child Localization System on RFID and Wireless Sensor Networks

    OpenAIRE

    Chao Chen

    2010-01-01

    Radio Frequency Identification (RFID) and wireless sensor networks are wireless technologies that rapidly emerge and show great potential. Combining RFID and wireless sensor networks provides a cost-efficient way to expand the RFID system's range and to enable an RFID system in areas without a network infrastructure. These two technologies are employed to build a wireless localization system in a children's theme park. The main purpose of this child localization system is to track and locate ...

  3. Precise Localization of Mobile Robots via Odometry and Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Guoyu Fu

    2013-04-01

    Full Text Available Precise localization of mobile robots in uncertain environments is a fundamental and crucial issue in robotics. In this paper, to deal with the unbounded accumulated errors of dead reckoning (DR-based localization, wireless sensor network (WSN-based localization is applied to calibrate the uncertainty of odometry using a Kalman filter (KF. In addition, to further aid in obtaining precise positions and reduce uncertainty, a novel backward dead reckoning (BDR localization approach is proposed. The experimental results demonstrate the success and reliability of the proposed method.

  4. Neighborhood Kalman Estimation for Distributed Localization in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Xiaochu Wang

    2016-01-01

    Full Text Available Accurate location information plays an important role in the performance of wireless sensor networks since many mission applications depend on it. This paper proposes a fully distributed localization algorithm based on the concept of data fusion, allowing the full intranodes information including the correlations among estimates to take part in the algorithm. By properly constructing and updating the estimates as well as the corresponding covariance matrices, the algorithm can fuse intranodes information to generate more accurate estimates on the sensor locations with a fast speed. Finally, numerical simulations are given as examples to demonstrate the effectiveness of the algorithm.

  5. A Least Square-Based Self-Adaptive Localization Method for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Baoguo Yu

    2016-01-01

    Full Text Available In the wireless sensor network (WSN localization methods based on Received Signal Strength Indicator (RSSI, it is usually required to determine the parameters of the radio signal propagation model before estimating the distance between the anchor node and an unknown node with reference to their communication RSSI value. And finally we use a localization algorithm to estimate the location of the unknown node. However, this localization method, though high in localization accuracy, has weaknesses such as complex working procedure and poor system versatility. Concerning these defects, a self-adaptive WSN localization method based on least square is proposed, which uses the least square criterion to estimate the parameters of radio signal propagation model, which positively reduces the computation amount in the estimation process. The experimental results show that the proposed self-adaptive localization method outputs a high processing efficiency while satisfying the high localization accuracy requirement. Conclusively, the proposed method is of definite practical value.

  6. Reputation-based secure sensor localization in wireless sensor networks.

    Science.gov (United States)

    He, Jingsha; Xu, Jing; Zhu, Xingye; Zhang, Yuqiang; Zhang, Ting; Fu, Wanqing

    2014-01-01

    Location information of sensor nodes in wireless sensor networks (WSNs) is very important, for it makes information that is collected and reported by the sensor nodes spatially meaningful for applications. Since most current sensor localization schemes rely on location information that is provided by beacon nodes for the regular sensor nodes to locate themselves, the accuracy of localization depends on the accuracy of location information from the beacon nodes. Therefore, the security and reliability of the beacon nodes become critical in the localization of regular sensor nodes. In this paper, we propose a reputation-based security scheme for sensor localization to improve the security and the accuracy of sensor localization in hostile or untrusted environments. In our proposed scheme, the reputation of each beacon node is evaluated based on a reputation evaluation model so that regular sensor nodes can get credible location information from highly reputable beacon nodes to accomplish localization. We also perform a set of simulation experiments to demonstrate the effectiveness of the proposed reputation-based security scheme. And our simulation results show that the proposed security scheme can enhance the security and, hence, improve the accuracy of sensor localization in hostile or untrusted environments.

  7. Distributed Water Pollution Source Localization with Mobile UV-Visible Spectrometer Probes in Wireless Sensor Networks.

    Science.gov (United States)

    Ma, Junjie; Meng, Fansheng; Zhou, Yuexi; Wang, Yeyao; Shi, Ping

    2018-02-16

    Pollution accidents that occur in surface waters, especially in drinking water source areas, greatly threaten the urban water supply system. During water pollution source localization, there are complicated pollutant spreading conditions and pollutant concentrations vary in a wide range. This paper provides a scalable total solution, investigating a distributed localization method in wireless sensor networks equipped with mobile ultraviolet-visible (UV-visible) spectrometer probes. A wireless sensor network is defined for water quality monitoring, where unmanned surface vehicles and buoys serve as mobile and stationary nodes, respectively. Both types of nodes carry UV-visible spectrometer probes to acquire in-situ multiple water quality parameter measurements, in which a self-adaptive optical path mechanism is designed to flexibly adjust the measurement range. A novel distributed algorithm, called Dual-PSO, is proposed to search for the water pollution source, where one particle swarm optimization (PSO) procedure computes the water quality multi-parameter measurements on each node, utilizing UV-visible absorption spectra, and another one finds the global solution of the pollution source position, regarding mobile nodes as particles. Besides, this algorithm uses entropy to dynamically recognize the most sensitive parameter during searching. Experimental results demonstrate that online multi-parameter monitoring of a drinking water source area with a wide dynamic range is achieved by this wireless sensor network and water pollution sources are localized efficiently with low-cost mobile node paths.

  8. Distributed Water Pollution Source Localization with Mobile UV-Visible Spectrometer Probes in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Junjie Ma

    2018-02-01

    Full Text Available Pollution accidents that occur in surface waters, especially in drinking water source areas, greatly threaten the urban water supply system. During water pollution source localization, there are complicated pollutant spreading conditions and pollutant concentrations vary in a wide range. This paper provides a scalable total solution, investigating a distributed localization method in wireless sensor networks equipped with mobile ultraviolet-visible (UV-visible spectrometer probes. A wireless sensor network is defined for water quality monitoring, where unmanned surface vehicles and buoys serve as mobile and stationary nodes, respectively. Both types of nodes carry UV-visible spectrometer probes to acquire in-situ multiple water quality parameter measurements, in which a self-adaptive optical path mechanism is designed to flexibly adjust the measurement range. A novel distributed algorithm, called Dual-PSO, is proposed to search for the water pollution source, where one particle swarm optimization (PSO procedure computes the water quality multi-parameter measurements on each node, utilizing UV-visible absorption spectra, and another one finds the global solution of the pollution source position, regarding mobile nodes as particles. Besides, this algorithm uses entropy to dynamically recognize the most sensitive parameter during searching. Experimental results demonstrate that online multi-parameter monitoring of a drinking water source area with a wide dynamic range is achieved by this wireless sensor network and water pollution sources are localized efficiently with low-cost mobile node paths.

  9. Distributed Water Pollution Source Localization with Mobile UV-Visible Spectrometer Probes in Wireless Sensor Networks

    Science.gov (United States)

    Zhou, Yuexi; Wang, Yeyao; Shi, Ping

    2018-01-01

    Pollution accidents that occur in surface waters, especially in drinking water source areas, greatly threaten the urban water supply system. During water pollution source localization, there are complicated pollutant spreading conditions and pollutant concentrations vary in a wide range. This paper provides a scalable total solution, investigating a distributed localization method in wireless sensor networks equipped with mobile ultraviolet-visible (UV-visible) spectrometer probes. A wireless sensor network is defined for water quality monitoring, where unmanned surface vehicles and buoys serve as mobile and stationary nodes, respectively. Both types of nodes carry UV-visible spectrometer probes to acquire in-situ multiple water quality parameter measurements, in which a self-adaptive optical path mechanism is designed to flexibly adjust the measurement range. A novel distributed algorithm, called Dual-PSO, is proposed to search for the water pollution source, where one particle swarm optimization (PSO) procedure computes the water quality multi-parameter measurements on each node, utilizing UV-visible absorption spectra, and another one finds the global solution of the pollution source position, regarding mobile nodes as particles. Besides, this algorithm uses entropy to dynamically recognize the most sensitive parameter during searching. Experimental results demonstrate that online multi-parameter monitoring of a drinking water source area with a wide dynamic range is achieved by this wireless sensor network and water pollution sources are localized efficiently with low-cost mobile node paths. PMID:29462929

  10. Saliency-Based Bleeding Localization for Wireless Capsule Endoscopy Diagnosis

    Directory of Open Access Journals (Sweden)

    Hongda Chen

    2017-01-01

    Full Text Available Stomach bleeding is a kind of gastrointestinal disease which can be diagnosed noninvasively by wireless capsule endoscopy (WCE. However, it requires much time for physicians to scan large amount of WCE images. Alternatively, computer-assisted bleeding localization systems are developed where color, edge, and intensity features are defined to distinguish lesions from normal tissues. This paper proposes a saliency-based localization system where three saliency maps are computed: phase congruency-based edge saliency map derived from Log-Gabor filter bands, intensity histogram-guided intensity saliency map, and red proportion-based saliency map. Fusing the three maps together, the proposed system can detect bleeding regions by thresholding the fused saliency map. Results demonstrate the accuracy of 98.97% for our system to mark bleeding regions.

  11. An energy-efficient underground localization system based on heterogeneous wireless networks.

    Science.gov (United States)

    Yuan, Yazhou; Chen, Cailian; Guan, Xinping; Yang, Qiuling

    2015-05-26

    A precision positioning system with energy efficiency is of great necessity for guaranteeing personnel safety in underground mines. The location information of the miners' should be transmitted to the control center timely and reliably; therefore, a heterogeneous network with the backbone based on high speed Industrial Ethernet is deployed. Since the mobile wireless nodes are working in an irregular tunnel, a specific wireless propagation model cannot fit all situations. In this paper, an underground localization system is designed to enable the adaptation to kinds of harsh tunnel environments, but also to reduce the energy consumption and thus prolong the lifetime of the network. Three key techniques are developed and implemented to improve the system performance, including a step counting algorithm with accelerometers, a power control algorithm and an adaptive packets scheduling scheme. The simulation study and experimental results show the effectiveness of the proposed algorithms and the implementation.

  12. An Energy-Efficient Underground Localization System Based on Heterogeneous Wireless Networks

    Directory of Open Access Journals (Sweden)

    Yazhou Yuan

    2015-05-01

    Full Text Available A precision positioning system with energy efficiency is of great necessity for guaranteeing personnel safety in underground mines. The location information of the miners’ should be transmitted to the control center timely and reliably; therefore, a heterogeneous network with the backbone based on high speed Industrial Ethernet is deployed. Since the mobile wireless nodes are working in an irregular tunnel, a specific wireless propagation model cannot fit all situations. In this paper, an underground localization system is designed to enable the adaptation to kinds of harsh tunnel environments, but also to reduce the energy consumption and thus prolong the lifetime of the network. Three key techniques are developed and implemented to improve the system performance, including a step counting algorithm with accelerometers, a power control algorithm and an adaptive packets scheduling scheme. The simulation study and experimental results show the effectiveness of the proposed algorithms and the implementation.

  13. Local, distributed topology control for large-scale wireless ad-hoc networks

    NARCIS (Netherlands)

    Nieberg, T.; Hurink, Johann L.

    In this document, topology control of a large-scale, wireless network by a distributed algorithm that uses only locally available information is presented. Topology control algorithms adjust the transmission power of wireless nodes to create a desired topology. The algorithm, named local power

  14. Adapting Mobile Beacon-Assisted Localization in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Wei Dong

    2009-04-01

    Full Text Available The ability to automatically locate sensor nodes is essential in many Wireless Sensor Network (WSN applications. To reduce the number of beacons, many mobile-assisted approaches have been proposed. Current mobile-assisted approaches for localization require special hardware or belong to centralized localization algorithms involving some deterministic approaches due to the fact that they explicitly consider the impreciseness of location estimates. In this paper, we first propose a range-free, distributed and probabilistic Mobile Beacon-assisted Localization (MBL approach for static WSNs. Then, we propose another approach based on MBL, called Adapting MBL (A-MBL, to increase the efficiency and accuracy of MBL by adapting the size of sample sets and the parameter of the dynamic model during the estimation process. Evaluation results show that the accuracy of MBL and A-MBL outperform both Mobile and Static sensor network Localization (MSL and Arrival and Departure Overlap (ADO when both of them use only a single mobile beacon for localization in static WSNs.

  15. Adapting mobile beacon-assisted localization in wireless sensor networks.

    Science.gov (United States)

    Teng, Guodong; Zheng, Kougen; Dong, Wei

    2009-01-01

    The ability to automatically locate sensor nodes is essential in many Wireless Sensor Network (WSN) applications. To reduce the number of beacons, many mobile-assisted approaches have been proposed. Current mobile-assisted approaches for localization require special hardware or belong to centralized localization algorithms involving some deterministic approaches due to the fact that they explicitly consider the impreciseness of location estimates. In this paper, we first propose a range-free, distributed and probabilistic Mobile Beacon-assisted Localization (MBL) approach for static WSNs. Then, we propose another approach based on MBL, called Adapting MBL (A-MBL), to increase the efficiency and accuracy of MBL by adapting the size of sample sets and the parameter of the dynamic model during the estimation process. Evaluation results show that the accuracy of MBL and A-MBL outperform both Mobile and Static sensor network Localization (MSL) and Arrival and Departure Overlap (ADO) when both of them use only a single mobile beacon for localization in static WSNs.

  16. Localization of Energy Harvesting Empowered Underwater Optical Wireless Sensor Networks

    KAUST Repository

    Saeed, Nasir

    2017-12-20

    In this paper, a received signal strength (RSS) based localization technique is developed for energy harvesting underwater optical wireless sensor networks (EH-UOWSNs), where the optical noise sources and channel impairments of seawater pose significant challenges for range estimation. Energy limitation is another major problem due to the limited battery power and difficulty in replacing or recharging the battery of an underwater sensor node. In the proposed framework, sensor nodes with insufficient battery, harvest the energy and starts communicating once it has sufficient energy storage. Network localization is carried out by measuring the RSSs of active nodes, which are modeled based on the underwater optical communication channel characteristics. Thereafter, block kernel matrices are computed for the RSS based range measurements. Unlike the traditional shortest-path approach, the proposed technique reduces the shortest path estimation for each block kernel matrix. Once the complete block kernel matrices are available, a closed form localization technique is developed to find the location of every optical sensor node in the network. Furthermore, an analytical expression for Cramer Rao lower bound (CRLB) is derived as a benchmark to compare the localization performance of the proposed technique. Finally, extensive simulations show that the proposed technique outperforms the well-known network localization techniques.

  17. Precise Localization and Formation Control of Swarm Robots via Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Han Wu

    2014-01-01

    Full Text Available Precise localization and formation control are one of the key technologies to achieve coordination and control of swarm robots, which is also currently a bottleneck for practical applications of swarm robotic systems. Aiming at overcoming the limited individual perception and the difficulty of achieving precise localization and formation, a localization approach combining dead reckoning (DR with wireless sensor network- (WSN- based methods is proposed in this paper. Two kinds of WSN localization technologies are adopted in this paper, that is, ZigBee-based RSSI (received signal strength indication global localization and electronic tag floors for calibration of local positioning. First, the DR localization information is combined with the ZigBee-based RSSI position information using the Kalman filter method to achieve precise global localization and maintain the robot formation. Then the electronic tag floors provide the robots with their precise coordinates in some local areas and enable the robot swarm to calibrate its formation by reducing the accumulated position errors. Hence, the overall performance of localization and formation control of the swarm robotic system is improved. Both of the simulation results and the experimental results on a real schematic system are given to demonstrate the success of the proposed approach.

  18. Design of a Child Localization System on RFID and Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Chao Chen

    2010-01-01

    Full Text Available Radio Frequency Identification (RFID and wireless sensor networks are wireless technologies that rapidly emerge and show great potential. Combining RFID and wireless sensor networks provides a cost-efficient way to expand the RFID system's range and to enable an RFID system in areas without a network infrastructure. These two technologies are employed to build a wireless localization system in a children's theme park. The main purpose of this child localization system is to track and locate children within a certain range near some landmarks in the park. The design experience in this project can be exported to other applications such as object tracking and surveillance.

  19. Centroid Localization of Uncooperative Nodes in Wireless Networks Using a Relative Span Weighting Method

    Directory of Open Access Journals (Sweden)

    Christine Laurendeau

    2010-01-01

    Full Text Available Increasingly ubiquitous wireless technologies require novel localization techniques to pinpoint the position of an uncooperative node, whether the target is a malicious device engaging in a security exploit or a low-battery handset in the middle of a critical emergency. Such scenarios necessitate that a radio signal source be localized by other network nodes efficiently, using minimal information. We propose two new algorithms for estimating the position of an uncooperative transmitter, based on the received signal strength (RSS of a single target message at a set of receivers whose coordinates are known. As an extension to the concept of centroid localization, our mechanisms weigh each receiver's coordinates based on the message's relative RSS at that receiver, with respect to the span of RSS values over all receivers. The weights may decrease from the highest RSS receiver either linearly or exponentially. Our simulation results demonstrate that for all but the most sparsely populated wireless networks, our exponentially weighted mechanism localizes a target node within the regulations stipulated for emergency services location accuracy.

  20. Antenna Radiation Pattern Influence on the Localization Accuracy in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    COCA, E.

    2013-05-01

    Full Text Available Localization or position determination is one of the most common applications for the wireless sensor networks. Many investigations have been made during the last decade, most of the effort being concentrated in the direction of improving the accuracy of the positioning results by using complex filtering and correction algorithms, and other techniques such as radio maps or directive antennas for the reference nodes. The most common sources of errors include reflections on nearby objects, radio frequency noise, and variable characteristics of the communication channel. In the vast majority of cases, several assumptions have been made in order to simplify the computing algorithms or the complexity of nodes, and finally their cost. The omnidirectional radiation pattern of the node antennas is such an assumption. In this paper we investigate theoretically and validate by measurements the influence of the radiation pattern on the localization accuracy of a wireless sensor node network. By taking into consideration the orientation of nodes, which could be provided by a local digital compass on each node, we demonstrate that the position accuracy could be improved with a minimum of resources. All measurements were made in radio emissions controlled environment - a semi-anechoic chamber, without affecting the generality of the proposed solution.

  1. Fuzzy logic congestion control in IEEE 802.11 wireless local area networks: A performance evaluation

    CSIR Research Space (South Africa)

    Nyirenda, CN

    2007-09-01

    Full Text Available In 802.11 Wireless Local Area Networks, the wired and the wireless interfaces of the Access Point are characterized by the disparity in channel capacity. This presents a significant bottleneck for traffic flowing from the wired network...

  2. A Three-Dimensional Wireless Indoor Localization System

    Directory of Open Access Journals (Sweden)

    Ping Yi

    2014-01-01

    Full Text Available Indoor localization, an emerging technology in location based service (LBS, is now playing a more and more important role both in commercial and in civilian industry. Global position system (GPS is the most popular solution in outdoor localization field, and the accuracy is around 10 meter error in positioning. However, with complex obstacles in buildings, problems rise in the “last mile” of localization field, which encourage a momentum of indoor localization. The traditional indoor localization system is either range-based or fingerprinting-based, which requires a lot of time and efforts to do the predeployment. In this paper, we present a 3-dimensional on-demand indoor localization system (3D-ODIL, which can be fingerprint-free and deployed rapidly in a multistorey building. The 3D-ODIL consists of two phases, vertical localization and horizontal localization. On vertical direction, we propose multistorey differential (MSD algorithm and implement it to fulfill the vertical localization, which can greatly reduce the number of anchors deployed. We use enhanced field division (EFD algorithm to conduct the horizontal localization. EFD algorithm is a range-free algorithm, the main idea of which is to dynamically divide the field within different signature area and position the target. The accuracy and performance have been validated through our extensive analysis and systematic experiments.

  3. Experience of wireless local area network in a radiation oncology department

    Directory of Open Access Journals (Sweden)

    Mandal Abhijit

    2010-01-01

    Full Text Available The aim of this work is to develop a wireless local area network (LAN between different types of users (Radiation Oncologists, Radiological Physicists, Radiation Technologists, etc for efficient patient data management and to made easy the availability of information (chair side to improve the quality of patient care in Radiation Oncology department. We have used mobile workstations (Laptops and stationary workstations, all equipped with wireless-fidelity (Wi-Fi access. Wireless standard 802.11g (as recommended by Institute of Electrical and Electronic Engineers (IEEE, Piscataway, NJ has been used. The wireless networking was configured with the Service Set Identifier (SSID, Media Access Control (MAC address filtering, and Wired Equivalent Privacy (WEP network securities. We are successfully using this wireless network in sharing the indigenously developed patient information management software. The proper selection of the hardware and the software combined with a secure wireless LAN setup will lead to a more efficient and productive radiation oncology department.

  4. Design and initial deployment of the wireless local area networking infrastructure at Sandia National Laboratories.

    Energy Technology Data Exchange (ETDEWEB)

    Long, John P.; Hamill, Michael J.; Mitchell, M. G.; Miller, Marc M.; Witzke, Edward L.; Wiener, Dallas J

    2006-11-01

    A major portion of the Wireless Networking Project at Sandia National Laboratories over the last few years has been to examine IEEE 802.11 wireless networking for possible use at Sandia and if practical, introduce this technology. This project team deployed 802.11a, b, and g Wireless Local Area Networking at Sandia. This report examines the basics of wireless networking and captures key results from project tests and experiments. It also records project members thoughts and designs on wireless LAN architecture and security issues. It documents some of the actions and milestones of this project, including pilot and production deployment of wireless networking equipment, and captures the team's rationale behind some of the decisions made. Finally, the report examines lessons learned, future directions, and conclusions.

  5. Wireless local area network in a prehospital environment

    Directory of Open Access Journals (Sweden)

    Grimes Gary J

    2004-08-01

    Full Text Available Abstract Background Wireless local area networks (WLANs are considered the next generation of clinical data network. They open the possibility for capturing clinical data in a prehospital setting (e.g., a patient's home using various devices, such as personal digital assistants, laptops, digital electrocardiogram (EKG machines, and even cellular phones, and transmitting the captured data to a physician or hospital. The transmission rate is crucial to the applicability of the technology in the prehospital setting. Methods We created two separate WLANs to simulate a virtual local are network environment such as in a patient's home or an emergency room (ER. The effects of different methods of data transmission, number of clients, and roaming among different access points on the file transfer rate were determined. Results The present results suggest that it is feasible to transfer small files such as patient demographics and EKG data from the patient's home to the ER at a reasonable speed. Encryption, user control, and access control were implemented and results discussed. Conclusions Implementing a WLAN in a centrally managed and multiple-layer-controlled access control server is the key to ensuring its security and accessibility. Future studies should focus on product capacity, speed, compatibility, interoperability, and security management.

  6. Wireless power pad with local power activation for portable devices

    NARCIS (Netherlands)

    Waffenschmidt, E.; Zheglov, V.

    2007-01-01

    Wireless power transfer by magnetic induction offers a simple to use way to recharge mobile devices like e.g. mobile phone, music players or medical sensors. As shown by a previous report and an existing Power Pad demonstrator, wireless inductive power transfer is possible with a good power

  7. Event Localization in Underwater Wireless Sensor Networks using Monitoring Courses

    KAUST Repository

    Debont, Matthew

    2011-11-01

    In this thesis we consider different methods to localize events in a multi-hop wireless sensor network operating underwater using acoustic modems. The network consists of surface gateway nodes and relay nodes. Localization of surface gateways can be achieved through GPS, but we cannot rely on this technology for localizing underwater nodes. Surface Gateway nodes can distribute their locations through the network using the incoming signals by the acoustic modems from the relay nodes. Relay nodes are deployed to remain static but due to water currents, floating, and the untethered nature of the nodes, they often suffer from frequent drifting which can result in a deployed network suffering link failures. In this work, we developed a novel concept of an underwater alarming system, which adapts a cyclic graph model. In the event of link failure, a series of alarm packets are broadcasted in the network. These alarms are then captured through a novel concept of underwater Monitoring Courses (M-Courses), which can also be used to assure network connectivity and identify node faults. M-Courses also allow the network to localize events and identify network issues at a local level before forwarding any results upwards to a Surface Gateway nodes. This reduces the amount of communication overhead needed and allowing for distributed management of nodes in a network which may be constantly moving. We show that the proposed algorithms can reduce the number of send operations needed for an event to be localized in a network. We have found that M-Course routing reduces the number of sends required to report an event to a Surface Gateway by up to 80% in some cases when compared to a naive routing implementation. But this is achieved by increasing the time for an event to reach a Surface Gateway. These effects are both due to the buffering effect of M-Course routing, which allows us to efficiently deal with multiple events in an local area and we find that the performance of M

  8. Multi-objective ant algorithm for wireless sensor network positioning

    International Nuclear Information System (INIS)

    Fidanova, S.; Shindarov, M.; Marinov, P.

    2013-01-01

    It is impossible to imagine our modern life without telecommunications. Wireless networks are a part of telecommunications. Wireless sensor networks (WSN) consist of spatially distributed sensors, which communicate in wireless way. This network monitors physical or environmental conditions. The objective is the full coverage of the monitoring region and less energy consumption of the network. The most appropriate approach to solve the problem is metaheuristics. In this paper the full coverage of the area is treated as a constrain. The objectives which are optimized are a minimal number of sensors and energy (lifetime) of the network. We apply multi-objective Ant Colony Optimization to solve this important telecommunication problem. We chose MAX-MIN Ant System approach, because it is proven to converge to the global optima

  9. High Resolution Robust GPS-free Localization for Wireless Sensor Networks and its Applications

    KAUST Repository

    Mirza, Mohammed

    2011-12-12

    In this thesis we investigate the problem of robustness and scalability w.r.t. estimating the position of randomly deployed motes/nodes of a Wireless Sensor Network (WSN) without the help of Global Positioning System (GPS) devices. We propose a few applications of range independent localization algorithms that allow the sensors to actively determine their location with high resolution without increasing the complexity of the hardware or any additional device setup. In our first application we try to present a localized and centralized cooperative spectrum sensing using RF sensor networks. This scheme collaboratively sense the spectrum and localize the whole network efficiently and with less difficulty. In second application we try to focus on how efficiently we can localize the nodes, to detect underwater threats, without the use of beacons. In third application we try to focus on 3-Dimensional localization for LTE systems. Our performance evaluation shows that these schemes lead to a significant improvement in localization accuracy compared to the state-of-art range independent localization schemes, without requiring GPS support.

  10. Detection test of wireless network signal strength and GPS positioning signal in underground pipeline

    Science.gov (United States)

    Li, Li; Zhang, Yunwei; Chen, Ling

    2018-03-01

    In order to solve the problem of selecting positioning technology for inspection robot in underground pipeline environment, the wireless network signal strength and GPS positioning signal testing are carried out in the actual underground pipeline environment. Firstly, the strength variation of the 3G wireless network signal and Wi-Fi wireless signal provided by China Telecom and China Unicom ground base stations are tested, and the attenuation law of these wireless signals along the pipeline is analyzed quantitatively and described. Then, the receiving data of the GPS satellite signal in the pipeline are tested, and the attenuation of GPS satellite signal under underground pipeline is analyzed. The testing results may be reference for other related research which need to consider positioning in pipeline.

  11. Multi-hop localization algorithm based on grid-scanning for wireless sensor networks.

    Science.gov (United States)

    Wan, Jiangwen; Guo, Xiaolei; Yu, Ning; Wu, Yinfeng; Feng, Renjian

    2011-01-01

    For large-scale wireless sensor networks (WSNs) with a minority of anchor nodes, multi-hop localization is a popular scheme for determining the geographical positions of the normal nodes. However, in practice existing multi-hop localization methods suffer from various kinds of problems, such as poor adaptability to irregular topology, high computational complexity, low positioning accuracy, etc. To address these issues in this paper, we propose a novel Multi-hop Localization algorithm based on Grid-Scanning (MLGS). First, the factors that influence the multi-hop distance estimation are studied and a more realistic multi-hop localization model is constructed. Then, the feasible regions of the normal nodes are determined according to the intersection of bounding square rings. Finally, a verifiably good approximation scheme based on grid-scanning is developed to estimate the coordinates of the normal nodes. Additionally, the positioning accuracy of the normal nodes can be improved through neighbors' collaboration. Extensive simulations are performed in isotropic and anisotropic networks. The comparisons with some typical algorithms of node localization confirm the effectiveness and efficiency of our algorithm.

  12. A Localization Based Cooperative Routing Protocol for Underwater Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Nadeem Javaid

    2017-01-01

    Full Text Available Localization is one of the major aspects in underwater wireless sensor networks (UWSNs. Therefore, it is important to know the accurate position of the sensor node in large scale applications like disaster prevention, tactical surveillance, and monitoring. Due to the inefficiency of the global positioning system (GPS in UWSN, it is very difficult to localize a node in underwater environment compared to terrestrial networks. To minimize the localization error and enhance the localization coverage of the network, two routing protocols are proposed; the first one is mobile autonomous underwater vehicle (MobiL-AUV and the second one is cooperative MobiL (CO-MobiL. In MobiL-AUV, AUVs are deployed and equipped with GPS and act as reference nodes. These reference nodes are used to localize all the nonlocalized ordinary sensor nodes in order to reduce the localization error and maximize the network coverage. CO-MobiL is presented in order to improve the network throughput by using the maximal ratio combining (MRC as diversity technique which combines both signals, received from the source and received from the relay at the destination. It uses amplify-and-forward (AF mechanism to improve the signal between the source and the destination. To support our claims, extensive simulations are performed.

  13. Practical Fingerprinting Localization for Indoor Positioning System by Using Beacons

    Directory of Open Access Journals (Sweden)

    Santosh Subedi

    2017-01-01

    Full Text Available Recent developments in the fields of smartphones and wireless communication technologies such as beacons, Wi-Fi, and ultra-wideband have made it possible to realize indoor positioning system (IPS with a few meters of accuracy. In this paper, an improvement over traditional fingerprinting localization is proposed by combining it with weighted centroid localization (WCL. The proposed localization method reduces the total number of fingerprint reference points over the localization space, thus minimizing both the time required for reading radio frequency signals and the number of reference points needed during the fingerprinting learning process, which eventually makes the process less time-consuming. The proposed positioning has two major steps of operation. In the first step, we have realized fingerprinting that utilizes lightly populated reference points (RPs and WCL individually. Using the location estimated at the first step, WCL is run again for the final location estimation. The proposed localization technique reduces the number of required fingerprint RPs by more than 40% compared to normal fingerprinting localization method with a similar localization estimation error.

  14. An 802.11 n wireless local area network transmission scheme for wireless telemedicine applications.

    Science.gov (United States)

    Lin, C F; Hung, S I; Chiang, I H

    2010-10-01

    In this paper, an 802.11 n transmission scheme is proposed for wireless telemedicine applications. IEEE 802.11n standards, a power assignment strategy, space-time block coding (STBC), and an object composition Petri net (OCPN) model are adopted. With the proposed wireless system, G.729 audio bit streams, Joint Photographic Experts Group 2000 (JPEG 2000) clinical images, and Moving Picture Experts Group 4 (MPEG-4) video bit streams achieve a transmission bit error rate (BER) of 10-7, 10-4, and 103 simultaneously. The proposed system meets the requirements prescribed for wireless telemedicine applications. An essential feature of this proposed transmission scheme is that clinical information that requires a high quality of service (QoS) is transmitted at a high power transmission rate with significant error protection. For maximizing resource utilization and minimizing the total transmission power, STBC and adaptive modulation techniques are used in the proposed 802.11 n wireless telemedicine system. Further, low power, direct mapping (DM), low-error protection scheme, and high-level modulation are adopted for messages that can tolerate a high BER. With the proposed transmission scheme, the required reliability of communication can be achieved. Our simulation results have shown that the proposed 802.11 n transmission scheme can be used for developing effective wireless telemedicine systems.

  15. Analysis of Wireless Capsule Endoscopy Images using Local Binary Patterns

    Directory of Open Access Journals (Sweden)

    Adriana Florentina CONSTANTINESCU

    2015-06-01

    Full Text Available Wireless capsule endoscopy, the gold standard in the screening and diagnosis of small bowel diseases, is one of the most recent investigations for gastrointestinal pathology. This examination has the advantages of being non-invasive, painless, with a large clinical yield, especially for small bowel diseases, but also some disadvantages. The long time necessary for reading and interpreting all frames acquired is one of these disadvantages. This inconvenient could be improved through different methods by using software applications. In this study we have used a software application for texture analysis based on local binary pattern (LBP operator. This operator detects and removes non-informative frames in a first step, then identifies potential lesions. Our study group consisted of 33 patients from the Gastroenterology and Hepatology Centre Craiova and from the 1st Internal Medicine and Gastroenterology Clinic from the Emergency County Hospital of Craiova. The patients included in the study have corresponded to our inclusion criteria established. The exclusion criteria were represented by the contraindications of the capsule endoscopy. In the first phase of the study, we have removed the non-informative frames from the original videos obtained, and we have acquired an average reduction of 6.96% from the total number of images. In the second phase, using the same LBP operator, we have correctly identified 93.16% of telangiectasia lesions. Our study demonstrated that software applications based on LBP operator can lead to a shorter analysis time, by reducing the overall frames number, and can also provide support in diagnosis.

  16. Handoff Between a Wireless Local Area Network (WLAN and a Wide Area Network (UMTS

    Directory of Open Access Journals (Sweden)

    J. Sánchez–García

    2009-04-01

    Full Text Available With the appearance of wireless data networks with variable coverage, band width and handoff strategies, in addition to the growing need of mobile nodes to freely roam among these networks, the support of an interoperable handoff strategy for hybrid wireless data networks is a requirement that needs to be addressed. The current trend in wireless data networks is to offer multimedia access to mobile users by employing the wireless local area network (WLAN standard IEEE802.11 while the user is located indoors; on the other hand, 3rd generation wireless networks (WAN are being deployed to provide coverage while the user is located outdoors. As a result, the mobile node will require a handoff mechanism to allow the user to roam between WLAN and WAN environments; up to this date several strategies have been proposed (Sattari et al., 2004 and HyoJin, 2007 in the literature, however, none of these have been standardized to date. To support this interoperability, the mobile node must be equipped with configurable wireless inetrfaces to support the handoff between the WLAN and the WAN networks. In this work a new algorithm is proposed to allow a mobile node to roam between a wireless local area network (IEEE802.11 and a WAN base station (UMTS, while employing IP mobility support. The algorithm is implemented in simulation, using the Network Simulator 2.

  17. Sparse Localization with a Mobile Beacon Based on LU Decomposition in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Chunhui Zhao

    2015-09-01

    Full Text Available Node localization is the core in wireless sensor network. It can be solved by powerful beacons, which are equipped with global positioning system devices to know their location information. In this article, we present a novel sparse localization approach with a mobile beacon based on LU decomposition. Our scheme firstly translates node localization problem into a 1-sparse vector recovery problem by establishing sparse localization model. Then, LU decomposition pre-processing is adopted to solve the problem that measurement matrix does not meet the re¬stricted isometry property. Later, the 1-sparse vector can be exactly recovered by compressive sensing. Finally, as the 1-sparse vector is approximate sparse, weighted Cen¬troid scheme is introduced to accurately locate the node. Simulation and analysis show that our scheme has better localization performance and lower requirement for the mobile beacon than MAP+GC, MAP-M, and MAP-MN schemes. In addition, the obstacles and DOI have little effect on the novel scheme, and it has great localization performance under low SNR, thus, the scheme proposed is robust.

  18. Wireless Capsule Gastrointestinal Endoscopy: Direction-of-Arrival Estimation Based Localization Survey.

    Science.gov (United States)

    Dey, Nilanjan; Ashour, Amira S; Shi, Fuqian; Sherratt, R Simon

    2017-01-01

    One of the significant challenges in capsule endoscopy (CE) is to precisely determine the pathologies location. The localization process is primarily estimated using the received signal strength (RSS) from sensors in the capsule system through its movement in the gastrointestinal (GI) tract. Consequently, the wireless CE (WCE) system requires improvement to handle the lack of the capsule instantaneous localization information and to solve the relatively low transmission data rate challenges. Furthermore, the association among the capsule's transmitter position, capsule location, signal reduction, and the capsule direction should be assessed. These measurements deliver significant information for the instantaneous capsule localization systems based on time-of-arrival approach, phase difference of arrival, RSS, electromagnetic, direction of arrival (DOA), and video tracking approaches are developed to locate the WCE precisely. This review introduces the acquisition concept of the GI medical images using the endoscopy with a comprehensive description of the endoscopy system components. Capsule localization and tracking are considered to be the most important features of the WCE system, thus this paper emphasizes the most common localization systems generally, highlighting the DOA-based localization systems and discusses the required significant research challenges to be addressed.

  19. GWO-LPWSN: Grey Wolf Optimization Algorithm for Node Localization Problem in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    R. Rajakumar

    2017-01-01

    Full Text Available Seyedali Mirjalili et al. (2014 introduced a completely unique metaheuristic technique particularly grey wolf optimization (GWO. This algorithm mimics the social behavior of grey wolves whereas it follows the leadership hierarchy and attacking strategy. The rising issue in wireless sensor network (WSN is localization problem. The objective of this problem is to search out the geographical position of unknown nodes with the help of anchor nodes in WSN. In this work, GWO algorithm is incorporated to spot the correct position of unknown nodes, so as to handle the node localization problem. The proposed work is implemented using MATLAB 8.2 whereas nodes are deployed in a random location within the desired network area. The parameters like computation time, percentage of localized node, and minimum localization error measures are utilized to analyse the potency of GWO rule with other variants of metaheuristics algorithms such as particle swarm optimization (PSO and modified bat algorithm (MBA. The observed results convey that the GWO provides promising results compared to the PSO and MBA in terms of the quick convergence rate and success rate.

  20. Software-Defined Radio for Wireless Local-Area Networks

    NARCIS (Netherlands)

    Schiphorst, Roelof

    2004-01-01

    New wireless communications standards do not replace old ones, instead the number of standards keeps on increasing and by now an abundance of standards exists. Moreover there is no reason to assume that this trend will ever stop. Therefore, the software-radio concept is emerging as a potential

  1. Raspberry Pi Based Intelligent Wireless Sensor Node for Localized Torrential Rain Monitoring

    Directory of Open Access Journals (Sweden)

    Zhaozhuo Xu

    2016-01-01

    Full Text Available Wireless sensor networks are proved to be effective in long-time localized torrential rain monitoring. However, the existing widely used architecture of wireless sensor networks for rain monitoring relies on network transportation and back-end calculation, which causes delay in response to heavy rain in localized areas. Our work improves the architecture by applying logistic regression and support vector machine classification to an intelligent wireless sensor node which is created by Raspberry Pi. The sensor nodes in front-end not only obtain data from sensors, but also can analyze the probabilities of upcoming heavy rain independently and give early warnings to local clients in time. When the sensor nodes send the probability to back-end server, the burdens of network transport are released. We demonstrate by simulation results that our sensor system architecture has potentiality to increase the local response to heavy rain. The monitoring capacity is also raised.

  2. A Survey on Wireless Transmitter Localization Using Signal Strength Measurements

    Directory of Open Access Journals (Sweden)

    Henri Nurminen

    2017-01-01

    Full Text Available Knowledge of deployed transmitters’ (Tx locations in a wireless network improves many aspects of network management. Operators and building administrators are interested in locating unknown Txs for optimizing new Tx placement, detecting and removing unauthorized Txs, selecting the nearest Tx to offload traffic onto it, and constructing radio maps for indoor and outdoor navigation. This survey provides a comprehensive review of existing algorithms that estimate the location of a wireless Tx given a set of observations with the received signal strength indication. Algorithms that require the observations to be location-tagged are suitable for outdoor mapping or small-scale indoor mapping, while algorithms that allow most observations to be unlocated trade off some accuracy to enable large-scale crowdsourcing. This article presents empirical evaluation of the algorithms using numerical simulations and real-world Bluetooth Low Energy data.

  3. Wireless Local Area Network Performance Inside Aircraft Passenger Cabins

    Science.gov (United States)

    Whetten, Frank L.; Soroker, Andrew; Whetten, Dennis A.; Whetten, Frank L.; Beggs, John H.

    2005-01-01

    An examination of IEEE 802.11 wireless network performance within an aircraft fuselage is performed. This examination measured the propagated RF power along the length of the fuselage, and the associated network performance: the link speed, total throughput, and packet losses and errors. A total of four airplanes: one single-aisle and three twin-aisle airplanes were tested with 802.11a, 802.11b, and 802.11g networks.

  4. Implementation of SNS Model for Intrusion Prevention in Wireless Local Area Network

    DEFF Research Database (Denmark)

    Isah, Abdullahi

    The thesis has proposed and implemented a so-called SNS (Social network security) model for intrusion prevention in the Wireless Local Area Network of an organization. An experimental design was used to implement and test the model at a university in Nigeria.......The thesis has proposed and implemented a so-called SNS (Social network security) model for intrusion prevention in the Wireless Local Area Network of an organization. An experimental design was used to implement and test the model at a university in Nigeria....

  5. Censoring for Bayesian Cooperative Positioning in Dense Wireless Networks

    NARCIS (Netherlands)

    Das, Kallol; Wymeersch, Henk

    2012-01-01

    Cooperative positioning is a promising solution for location-enabled technologies in GPS-challenged environments. However, it suffers from high computational complexity and increased network traffic, compared to traditional positioning approaches. The computational complexity is related to the

  6. Node localization algorithm of wireless sensor network for large electrical equipment monitoring application

    DEFF Research Database (Denmark)

    Chen, Qinyin; Hu, Y.; Chen, Zhe

    2016-01-01

    Node localization technology is an important technology for the Wireless Sensor Networks (WSNs) applications. An improved 3D node localization algorithm is proposed in this paper, which is based on a Multi-dimensional Scaling (MDS) node localization algorithm for large electrical equipment...... is based on the combination of node's Time of Arrival (TOA) and Angle of Arrival (AOA) measurement information. Simulation results show the proposed algorithm outperforms than the traditional Multidimensional Scaling (MDS-MAP) algorithm....

  7. Wireless Sensor Networks - Node Localization for Various Industry Problems

    International Nuclear Information System (INIS)

    Derr, Kurt; Manic, Milos

    2015-01-01

    Fast, effective monitoring following airborne releases of toxic substances is critical to mitigate risks to threatened population areas. Wireless sensor nodes at fixed predetermined locations may monitor such airborne releases and provide early warnings to the public. A challenging algorithmic problem is determining the locations to place these sensor nodes while meeting several criteria: 1) provide complete coverage of the domain, and 2) create a topology with problem dependent node densities, while 3) minimizing the number of sensor nodes. This manuscript presents a novel approach to determining optimal sensor placement, Advancing Front mEsh generation with Constrained dElaunay Triangulation and Smoothing (AFECETS) that addresses these criteria. A unique aspect of AFECETS is the ability to determine wireless sensor node locations for areas of high interest (hospitals, schools, high population density areas) that require higher density of nodes for monitoring environmental conditions, a feature that is difficult to find in other research work. The AFECETS algorithm was tested on several arbitrary shaped domains. AFECETS simulation results show that the algorithm 1) provides significant reduction in the number of nodes, in some cases over 40%, compared to an advancing front mesh generation algorithm, 2) maintains and improves optimal spacing between nodes, and 3) produces simulation run times suitable for real-time applications

  8. Experimental demonstration of a novel indoor optical wireless localization system for high-speed personal area networks.

    Science.gov (United States)

    Wang, Ke; Nirmalathas, Ampalavanapillai; Lim, Christina; Skafidas, Efstratios

    2015-04-01

    In this Letter, we propose a novel indoor localization system based on optical wireless technology. By using the same architecture as the high-speed full-duplex indoor optical wireless communication system, the "search and scan" process, and the added transmission power and beam footprint information in the "search and scan" message, indoor localization functionality is achieved. Proof-of-concept experiments are carried out, and results show that an average error of optical wireless communication system, high-speed indoor wireless personal area networks can be achieved.

  9. A Survey of Indoor Positioning Systems for Wireless Personal Networks

    NARCIS (Netherlands)

    Gu, Y.; Lo, A.; Niemegeers, I.

    2009-01-01

    Recently, indoor positioning systems (IPSs) have been designed to provide location information of persons and devices. The position information enables location-based protocols for user applications. Personal networks (PNs) are designed to meet the users' needs and interconnect users' devices

  10. Advanced Wireless Local Area Networks in the Unlicensed Sub-1GHz ISM-bands

    NARCIS (Netherlands)

    Aust, S.H.

    2014-01-01

    This dissertation addresses the challenges of wireless local area networks (WLANs) that operate in the unlicensed sub-1GHz industrial, scientific, and medical (ISM) band. Frequencies in the 900MHz spectrum enable a wider coverage due to the longer propagation characteristics of the radio waves. To

  11. Double dipole antenna for dual-band wireless local area networks applications

    CSIR Research Space (South Africa)

    Steyn, JM

    2009-09-01

    Full Text Available A double dipole antenna design is proposed for wireless local area network (WLAN) applications. Two parallel dipoles are used to facilitate operation in both the standard WLAN frequency bands (IEEE 802.11b and IEEE 802.11a) simultaneously. The lower...

  12. Positioning system in wireless sensor networks using NS-2

    CSIR Research Space (South Africa)

    Abu-Mahfouz, Adnan M

    2012-10-01

    Full Text Available and techniques require that the positions of the sensor nodes be determined. Localisation algorithms (e.g.[1-5]) follow several approaches to estimate positions of sensor nodes. One approach is to use special nodes, called beacons, which know their own... and analysing its performance have made simulation essential for the study of WSNs. Simulation is widely used in system modelling for applications ranging from engineering research, business analysis, manufacturing planning and biological science...

  13. A Localization-Free Interference and Energy Holes Minimization Routing for Underwater Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Anwar Khan

    2018-01-01

    Full Text Available Interference and energy holes formation in underwater wireless sensor networks (UWSNs threaten the reliable delivery of data packets from a source to a destination. Interference also causes inefficient utilization of the limited battery power of the sensor nodes in that more power is consumed in the retransmission of the lost packets. Energy holes are dead nodes close to the surface of water, and their early death interrupts data delivery even when the network has live nodes. This paper proposes a localization-free interference and energy holes minimization (LF-IEHM routing protocol for UWSNs. The proposed algorithm overcomes interference during data packet forwarding by defining a unique packet holding time for every sensor node. The energy holes formation is mitigated by a variable transmission range of the sensor nodes. As compared to the conventional routing protocols, the proposed protocol does not require the localization information of the sensor nodes, which is cumbersome and difficult to obtain, as nodes change their positions with water currents. Simulation results show superior performance of the proposed scheme in terms of packets received at the final destination and end-to-end delay.

  14. A Localization-Free Interference and Energy Holes Minimization Routing for Underwater Wireless Sensor Networks.

    Science.gov (United States)

    Khan, Anwar; Ahmedy, Ismail; Anisi, Mohammad Hossein; Javaid, Nadeem; Ali, Ihsan; Khan, Nawsher; Alsaqer, Mohammed; Mahmood, Hasan

    2018-01-09

    Interference and energy holes formation in underwater wireless sensor networks (UWSNs) threaten the reliable delivery of data packets from a source to a destination. Interference also causes inefficient utilization of the limited battery power of the sensor nodes in that more power is consumed in the retransmission of the lost packets. Energy holes are dead nodes close to the surface of water, and their early death interrupts data delivery even when the network has live nodes. This paper proposes a localization-free interference and energy holes minimization (LF-IEHM) routing protocol for UWSNs. The proposed algorithm overcomes interference during data packet forwarding by defining a unique packet holding time for every sensor node. The energy holes formation is mitigated by a variable transmission range of the sensor nodes. As compared to the conventional routing protocols, the proposed protocol does not require the localization information of the sensor nodes, which is cumbersome and difficult to obtain, as nodes change their positions with water currents. Simulation results show superior performance of the proposed scheme in terms of packets received at the final destination and end-to-end delay.

  15. Performance considerations for efficient multimedia streaming in wireless local area networks

    Science.gov (United States)

    Krishnaswamy, Dilip; Stacey, Robert J.; van Alstine, Ryan; Chimitt, William J.

    2004-11-01

    This paper presents investigates multimedia streaming over wireless local area networks. Physical layer sigmoid analytical models are presented for 802.11a/g and for 2x3 MIMO 802.11n MIMO-based systems are presented. Performance results in a wireless LAN environment are presented for traffic using UDP and TCP transport mechanisms. Packet losses are observed in WLAN environments which affects the overall throughput available. Possibilities for performance improvements with the use of 802.11e and MIMO technologies are discussed. System platform architecture performance issues for wireless video conferencing between Intel« PXA27x processor-based handheld platforms are presented and results with retry-limit adaptation are also presented.

  16. An Implementation of Error Minimization Position Estimate in Wireless Inertial Measurement Unit using Modification ZUPT

    Directory of Open Access Journals (Sweden)

    Adytia Darmawan

    2016-12-01

    Full Text Available Position estimation using WIMU (Wireless Inertial Measurement Unit is one of emerging technology in the field of indoor positioning systems. WIMU can detect movement and does not depend on GPS signals. The position is then estimated using a modified ZUPT (Zero Velocity Update method that was using Filter Magnitude Acceleration (FMA, Variance Magnitude Acceleration (VMA and Angular Rate (AR estimation. Performance of this method was justified on a six-legged robot navigation system. Experimental result shows that the combination of VMA-AR gives the best position estimation.

  17. PERFORMANCE EVALUATION OF LOCAL BARRIER COVERAGE IN WIRELESS SENSOR NETWORKS

    OpenAIRE

    K. K. Kannan

    2017-01-01

    The main aim of project is to create appropriate model of coverage for movement detection applications such as intrusion detection. However it has been proved that given sensor deployment sensors cannot locally determine whether deployment provides global coverage. Making it impossible to develop localized algorithms thus limiting it Dees use in practice. In this project I am introducing the concept of local barrier coverage to address this limitation. It is motivated by the observation that ...

  18. 3D magnetic-resonance-coupling (MRC) localization of wireless capsule endoscopy

    DEFF Research Database (Denmark)

    Xia, Yongming; Zhang, Lihui; Lu, Kaiyuan

    2016-01-01

    Wireless Capsule Endoscope (WCE) enables developing actively controlled capsule for potential complex surgeries, imaging, and new medicine tests. These tasks of WCE need safe, efficient, and precise 3D localization techniques. In this paper, a new application of the magnetic resonance coupling (MRC......) technique, which has been widely developed for efficient wireless power transfer, is introduced. It is proposed that the distance dependent signal strength in a MRC system can be beneficially used for 3D localization. The new 3D-MRC localization system consists of three orthogonal emitting coils which...... are powered by a battery in the capsule, and three pairs of orthogonal receiving coils which are placed outside human body. The distances between the WCE and the receiving coils can be estimated with good accuracy by studying the signal strengths in individual receiving coils. The proposed new 3D-MRC...

  19. Accuracy Enhancements for Positioning of Mobile Devices in Wireless Communication Networks

    DEFF Research Database (Denmark)

    Figueiras, Joao

    Positioning of mobile devices in wireless communication networks is nowadays being intensively investigated due to the combined benefit of location information and communication. Typical solutions for such scenario rely on robust algorithms that estimate position from indirect measurements...... systems. Since the measurement sampling is also important for tracking moving devices, the first analysis concerns the latency time for obtaining location information in short-range ad-hoc networks. Bluetooth is the elected technology since it is an actual example of such kind of networks. Simulations......, tracking wireless devices is a challenging problem. In order to get better results, we propose a solution which restricts the movement models of the mobile devices. This restriction, by relying on the assumption that users typically move in segment-wise linear trajectories, outperforms the standard...

  20. Dead Reckoning Localization Technique for Mobile Wireless Sensor Networks

    OpenAIRE

    Rashid, Haroon; Turuk, Ashok Kumar

    2015-01-01

    Full paper at: http://arxiv.org/pdf/1504.06797.pdfThis paper shows how a mobile node can be localized with less than three beacon nodes. It uses a technique known as dead-reckoning for localization of nodes at specific intervals

  1. High Efficiency, Low EMI and Positioning Tolerant Wireless Charging of EVs

    Energy Technology Data Exchange (ETDEWEB)

    Chabaan, Rakan [Hyundai American Technical Center

    2012-10-01

    The objective of this project is to develop, implement, and demonstrate a wireless power transfer (WPT) system that is capable of the following metrics: Total system efficiencies of more than 85 percent with minimum 20 cm coil-to-coil gap; System output power at least 6.6 kW; but design system up to 19.2 kW for future higher power study; Maximum lateral positioning tolerance achievable while meeting regulatory emission guidelines.

  2. Wireless Positioning Based on a Segment-Wise Linear Approach for Modeling the Target Trajectory

    DEFF Research Database (Denmark)

    Figueiras, Joao; Pedersen, Troels; Schwefel, Hans-Peter

    2008-01-01

    Positioning solutions in infrastructure-based wireless networks generally operate by exploiting the channel information of the links between the Wireless Devices and fixed networking Access Points. The major challenge of such solutions is the modeling of both the noise properties of the channel...... measurements and the user mobility patterns. One class of typical human being movement patterns is the segment-wise linear approach, which is studied in this paper. Current tracking solutions, such as the Constant Velocity model, hardly handle such segment-wise linear patterns. In this paper we propose...... a segment-wise linear model, called the Drifting Points model. The model results in an increased performance when compared with traditional solutions....

  3. DETECTION AND LOCALIZATION OF MULTIPLE SPOOFING ATTACKERS FOR MOBILE WIRELESS NETWORKS

    Directory of Open Access Journals (Sweden)

    R. Maivizhi

    2015-06-01

    Full Text Available The openness nature of wireless networks allows adversaries to easily launch variety of spoofing attacks and causes havoc in network performance. Recent approaches used Received Signal Strength (RSS traces, which only detect spoofing attacks in mobile wireless networks. However, it is not always desirable to use these methods as RSS values fluctuate significantly over time due to distance, noise and interference. In this paper, we discusses a novel approach, Mobile spOofing attack DEtection and Localization in WIireless Networks (MODELWIN system, which exploits location information about nodes to detect identity-based spoofing attacks in mobile wireless networks. Also, this approach determines the number of attackers who used the same node identity to masquerade as legitimate device. Moreover, multiple adversaries can be localized accurately. By eliminating attackers the proposed system enhances network performance. We have evaluated our technique through simulation using an 802.11 (WiFi network and an 802.15.4 (Zigbee networks. The results prove that MODELWIN can detect spoofing attacks with a very high detection rate and localize adversaries accurately.

  4. SeRLoc: Robust Localization for Wireless Sensor Networks

    National Research Council Canada - National Science Library

    Lazos, Loukas; Poovendran, Radha

    2005-01-01

    .... We show that SeRLoc is robust against known attacks on WSNs such as the wormhole attack, the Sybil attack, and compromise of network entities and analytically compute the probability of success for each attack. We also compare the performance of SeRLoc with state-of-the-art range-independent localization schemes and show that SeRLoc has better performance.

  5. Fuzzy mobile-robot positioning in intelligent spaces using wireless sensor networks.

    Science.gov (United States)

    Herrero, David; Martínez, Humberto

    2011-01-01

    This work presents the development and experimental evaluation of a method based on fuzzy logic to locate mobile robots in an Intelligent Space using wireless sensor networks (WSNs). The problem consists of locating a mobile node using only inter-node range measurements, which are estimated by radio frequency signal strength attenuation. The sensor model of these measurements is very noisy and unreliable. The proposed method makes use of fuzzy logic for modeling and dealing with such uncertain information. Besides, the proposed approach is compared with a probabilistic technique showing that the fuzzy approach is able to handle highly uncertain situations that are difficult to manage by well-known localization methods.

  6. Extension to HiRLoc Algorithm for Localization Error Computation in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Swati Saxena

    2013-09-01

    Full Text Available Wireless sensor networks (WSNs have gained importance in recent years as this support a large spectrum of applications such as automotive, health, military, environmental, home and office. Various algorithms have been proposed for making this technology more adaptive the existing algorithms address issues such as safety, security, power consumption, lifetime and localization. This paper presents an extension to HiRLoc algorithm and highlights its benefits. Extended HiRLoc significantly reduce the average localization error by suggesting a new method directional antenna based scheme.

  7. Interference-Aware Radio Resource Management for Local Area Wireless Networks

    Directory of Open Access Journals (Sweden)

    Ribeiro CássioB

    2011-01-01

    Full Text Available Interference-aware multiple access is an enabler to cost-efficient and reliable high data-rate local area wireless access. In this paper, we propose an interference-aware radio resource management scheme where receivers inform about their throughput, interference, and signal levels by means of broadcast messages tied to data reception. In the proposed scheme, the conventional scheduler is extended to interference-aware operation where individual scheduling decisions are based on estimated change in system-level performance. The performance of the proposed scheme is evaluated in system simulations where it is compared to a conventional scheduler and a centralized scheduler (global optimum. The convergence of the proposed scheduler is analyzed and signaling overhead of an example implementation is characterized. The results demonstrate that the proposed scheme enables fair and efficient wireless access in challenging interference scenarios, for example, multiple networks deployed in the same geographical area and sharing a common band.

  8. An MEF-Based Localization Algorithm against Outliers in Wireless Sensor Networks.

    Science.gov (United States)

    Wang, Dandan; Wan, Jiangwen; Wang, Meimei; Zhang, Qiang

    2016-07-07

    Precise localization has attracted considerable interest in Wireless Sensor Networks (WSNs) localization systems. Due to the internal or external disturbance, the existence of the outliers, including both the distance outliers and the anchor outliers, severely decreases the localization accuracy. In order to eliminate both kinds of outliers simultaneously, an outlier detection method is proposed based on the maximum entropy principle and fuzzy set theory. Since not all the outliers can be detected in the detection process, the Maximum Entropy Function (MEF) method is utilized to tolerate the errors and calculate the optimal estimated locations of unknown nodes. Simulation results demonstrate that the proposed localization method remains stable while the outliers vary. Moreover, the localization accuracy is highly improved by wisely rejecting outliers.

  9. A Secure Localization Approach Using Mutual Authentication and Insider Node Validation in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Gulshan Kumar

    2017-01-01

    Full Text Available Localization is a concerning issue in the applications of wireless sensor networks. Along with the accuracy of the location estimation of the sensor nodes, the security of the estimation is another priority. Wireless sensor networks often face various attacks where the attackers try to manipulate the estimated location or try to provide false beacons. In this paper, we have proposed a methodology that will address this problem of security aspects in localization of the sensor nodes. Moreover, we have considered the network environment with random node deployment and mobility as these two conditions are less addressed in previous research works. Further, our proposed algorithm provides low overhead due to the usage of less control messages in a limited transmission range. In addition, we have also proposed an algorithm to detect the malicious anchor nodes inside the network. The simulated results show that our proposed algorithm is efficient in terms of time consumption, localization accuracy, and localization ratio in the presence of malicious nodes.

  10. Structural Health Monitoring of Wind Turbine Blades: Acoustic Source Localization Using Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Omar Mabrok Bouzid

    2015-01-01

    Full Text Available Structural health monitoring (SHM is important for reducing the maintenance and operation cost of safety-critical components and systems in offshore wind turbines. This paper proposes an in situ wireless SHM system based on an acoustic emission (AE technique. By using this technique a number of challenges are introduced due to high sampling rate requirements, limitations in the communication bandwidth, memory space, and power resources. To overcome these challenges, this paper focused on two elements: (1 the use of an in situ wireless SHM technique in conjunction with the utilization of low sampling rates; (2 localization of acoustic sources which could emulate impact damage or audible cracks caused by different objects, such as tools, bird strikes, or strong hail, all of which represent abrupt AE events and could affect the structural health of a monitored wind turbine blade. The localization process is performed using features extracted from aliased AE signals based on a developed constraint localization model. To validate the performance of these elements, the proposed system was tested by testing the localization of the emulated AE sources acquired in the field.

  11. Sequential Monte Carlo Localization Methods in Mobile Wireless Sensor Networks: A Review

    Directory of Open Access Journals (Sweden)

    Ammar M. A. Abu Znaid

    2017-01-01

    Full Text Available The advancement of digital technology has increased the deployment of wireless sensor networks (WSNs in our daily life. However, locating sensor nodes is a challenging task in WSNs. Sensing data without an accurate location is worthless, especially in critical applications. The pioneering technique in range-free localization schemes is a sequential Monte Carlo (SMC method, which utilizes network connectivity to estimate sensor location without additional hardware. This study presents a comprehensive survey of state-of-the-art SMC localization schemes. We present the schemes as a thematic taxonomy of localization operation in SMC. Moreover, the critical characteristics of each existing scheme are analyzed to identify its advantages and disadvantages. The similarities and differences of each scheme are investigated on the basis of significant parameters, namely, localization accuracy, computational cost, communication cost, and number of samples. We discuss the challenges and direction of the future research work for each parameter.

  12. Incentive Compatible and Globally Efficient Position Based Routing for Selfish Reverse Multicast in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Sarvesh Varatharajan

    2009-10-01

    Full Text Available We consider the problem of all-to-one selfish routing in the absence of a payment scheme in wireless sensor networks, where a natural model for cost is the power required to forward, referring to the resulting game as a Locally Minimum Cost Forwarding (LMCF. Our objective is to characterize equilibria and their global costs in terms of stretch and diameter, in particular finding incentive compatible algorithms that are also close to globally optimal. We find that although social costs for equilibria of LMCF exhibit arbitrarily bad worst-case bounds and computational infeasibility of reaching optimal equilibria, there exist greedy and local incentive compatible heuristics achieving near-optimal global costs.

  13. A Novel Partial Discharge Localization Method in Substation Based on a Wireless UHF Sensor Array.

    Science.gov (United States)

    Li, Zhen; Luo, Lingen; Zhou, Nan; Sheng, Gehao; Jiang, Xiuchen

    2017-08-18

    Effective Partial Discharge (PD) localization can detect the insulation problems of the power equipment in a substation and improve the reliability of power systems. Typical Ultra-High Frequency (UHF) PD localization methods are mainly based on time difference information, which need a high sampling rate system. This paper proposes a novel PD localization method based on a received signal strength indicator (RSSI) fingerprint to quickly locate the power equipment with potential insulation defects. The proposed method consists of two stages. In the offline stage, the RSSI fingerprint data of the detection area is measured by a wireless UHF sensor array and processed by a clustering algorithm to reduce the PD interference and abnormal RSSI values. In the online stage, when PD happens, the RSSI fingerprint of PD is measured via the input of pattern recognition for PD localization. To achieve an accurate localization, the pattern recognition process is divided into two steps: a preliminary localization is implemented by cluster recognition to reduce the localization region, and the compressed sensing algorithm is used for accurate PD localization. A field test in a substation indicates that the mean localization error of the proposed method is 1.25 m, and 89.6% localization errors are less than 3 m.

  14. PlayNCool: Opportunistic Network Coding for Local Optimization of Routing in Wireless Mesh Networks

    DEFF Research Database (Denmark)

    Pahlevani, Peyman; Roetter, Daniel Enrique Lucani; Pedersen, Morten Videbæk

    2013-01-01

    This paper introduces PlayNCool, an opportunistic protocol with local optimization based on network coding to increase the throughput of a wireless mesh network (WMN). PlayNCool aims to enhance current routing protocols by (i) allowing random linear network coding transmissions end-to-end, (ii...... in large scale mesh networks. We show that PlayNCool can provide gains of more than 3x in individual links, which translates into a large end-to-end throughput improvement, and that it provides higher gains when more nodes in the network contend for the channel at the MAC layer, making it particularly...... relevant for dense mesh networks....

  15. Optimization of locations of diffusion spots in indoor optical wireless local area networks

    Science.gov (United States)

    Eltokhey, Mahmoud W.; Mahmoud, K. R.; Ghassemlooy, Zabih; Obayya, Salah S. A.

    2018-03-01

    In this paper, we present a novel optimization of the locations of the diffusion spots in indoor optical wireless local area networks, based on the central force optimization (CFO) scheme. The users' performance uniformity is addressed by using the CFO algorithm, and adopting different objective function's configurations, while considering maximization and minimization of the signal to noise ratio and the delay spread, respectively. We also investigate the effect of varying the objective function's weights on the system and the users' performance as part of the adaptation process. The results show that the proposed objective function configuration-based optimization procedure offers an improvement of 65% in the standard deviation of individual receivers' performance.

  16. Constrained State Estimation for Individual Localization in Wireless Body Sensor Networks

    Directory of Open Access Journals (Sweden)

    Xiaoxue Feng

    2014-11-01

    Full Text Available Wireless body sensor networks based on ultra-wideband radio have recently received much research attention due to its wide applications in health-care, security, sports and entertainment. Accurate localization is a fundamental problem to realize the development of effective location-aware applications above. In this paper the problem of constrained state estimation for individual localization in wireless body sensor networks is addressed. Priori knowledge about geometry among the on-body nodes as additional constraint is incorporated into the traditional filtering system. The analytical expression of state estimation with linear constraint to exploit the additional information is derived. Furthermore, for nonlinear constraint, first-order and second-order linearizations via Taylor series expansion are proposed to transform the nonlinear constraint to the linear case. Examples between the first-order and second-order nonlinear constrained filters based on interacting multiple model extended kalman filter (IMM-EKF show that the second-order solution for higher order nonlinearity as present in this paper outperforms the first-order solution, and constrained IMM-EKF obtains superior estimation than IMM-EKF without constraint. Another brownian motion individual localization example also illustrates the effectiveness of constrained nonlinear iterative least square (NILS, which gets better filtering performance than NILS without constraint.

  17. Information technology -- Telecommunications and information exchange between systems -- Local and metropolitan area networks -- Specific requirements -- Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications

    CERN Document Server

    International Organization for Standardization. Geneva

    1997-01-01

    Information technology -- Telecommunications and information exchange between systems -- Local and metropolitan area networks -- Specific requirements -- Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications

  18. An Effective Cuckoo Search Algorithm for Node Localization in Wireless Sensor Network.

    Science.gov (United States)

    Cheng, Jing; Xia, Linyuan

    2016-08-31

    Localization is an essential requirement in the increasing prevalence of wireless sensor network (WSN) applications. Reducing the computational complexity, communication overhead in WSN localization is of paramount importance in order to prolong the lifetime of the energy-limited sensor nodes and improve localization performance. This paper proposes an effective Cuckoo Search (CS) algorithm for node localization. Based on the modification of step size, this approach enables the population to approach global optimal solution rapidly, and the fitness of each solution is employed to build mutation probability for avoiding local convergence. Further, the approach restricts the population in the certain range so that it can prevent the energy consumption caused by insignificant search. Extensive experiments were conducted to study the effects of parameters like anchor density, node density and communication range on the proposed algorithm with respect to average localization error and localization success ratio. In addition, a comparative study was conducted to realize the same localization task using the same network deployment. Experimental results prove that the proposed CS algorithm can not only increase convergence rate but also reduce average localization error compared with standard CS algorithm and Particle Swarm Optimization (PSO) algorithm.

  19. Optical wireless communication using positive real-valued orthogonal frequency-division multiplexing and optical beamforming

    Science.gov (United States)

    Kim, Sung-Man; Kwon, Ki-Keun

    2017-07-01

    The relatively unsatisfactory performance of optical wireless communication (OWC) with respect to WiFi and millimeter-wave communications has formed a key issue preventing its commercialization. We experimentally demonstrate an OWC technology using a combination of positive real-valued orthogonal frequency-division multiplexing (OFDM) and optical beamforming (OB). Due to the intensity-modulation and direct-detection aspects of OWC systems, a positive real-valued OFDM signal can be suitably utilized to maximize the OWC data rate. Further, the OB technique, which can focus laser light on a desired target, can be utilized to increase the OWC data rate and transmission distance. Our experimental results show that the received optical signal power and electrical signal increase by up to 42 and 25 dB, respectively. Further, the data rate increases by a factor of 200 with OB over the conventional approach.

  20. A Robust High-Accuracy Ultrasound Indoor Positioning System Based on a Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Jun Qi

    2017-11-01

    Full Text Available This paper describes the development and implementation of a robust high-accuracy ultrasonic indoor positioning system (UIPS. The UIPS consists of several wireless ultrasonic beacons in the indoor environment. Each of them has a fixed and known position coordinate and can collect all the transmissions from the target node or emit ultrasonic signals. Every wireless sensor network (WSN node has two communication modules: one is WiFi, that transmits the data to the server, and the other is the radio frequency (RF module, which is only used for time synchronization between different nodes, with accuracy up to 1 μs. The distance between the beacon and the target node is calculated by measuring the time-of-flight (TOF for the ultrasonic signal, and then the position of the target is computed by some distances and the coordinate of the beacons. TOF estimation is the most important technique in the UIPS. A new time domain method to extract the envelope of the ultrasonic signals is presented in order to estimate the TOF. This method, with the envelope detection filter, estimates the value with the sampled values on both sides based on the least squares method (LSM. The simulation results show that the method can achieve envelope detection with a good filtering effect by means of the LSM. The highest precision and variance can reach 0.61 mm and 0.23 mm, respectively, in pseudo-range measurements with UIPS. A maximum location error of 10.2 mm is achieved in the positioning experiments for a moving robot, when UIPS works on the line-of-sight (LOS signal.

  1. Intelligent visual localization of wireless capsule endoscopes enhanced by color information.

    Science.gov (United States)

    Dimas, George; Spyrou, Evaggelos; Iakovidis, Dimitris K; Koulaouzidis, Anastasios

    2017-10-01

    Wireless capsule endoscopy (WCE) is performed with a miniature swallowable endoscope enabling the visualization of the whole gastrointestinal (GI) tract. One of the most challenging problems in WCE is the localization of the capsule endoscope (CE) within the GI lumen. Contemporary, radiation-free localization approaches are mainly based on the use of external sensors and transit time estimation techniques, with practically low localization accuracy. Latest advances for the solution of this problem include localization approaches based solely on visual information from the CE camera. In this paper we present a novel visual localization approach based on an intelligent, artificial neural network, architecture which implements a generic visual odometry (VO) framework capable of estimating the motion of the CE in physical units. Unlike the conventional, geometric, VO approaches, the proposed one is adaptive to the geometric model of the CE used; therefore, it does not require any prior knowledge about and its intrinsic parameters. Furthermore, it exploits color as a cue to increase localization accuracy and robustness. Experiments were performed using a robotic-assisted setup providing ground truth information about the actual location of the CE. The lowest average localization error achieved is 2.70 ± 1.62 cm, which is significantly lower than the error obtained with the geometric approach. This result constitutes a promising step towards the in-vivo application of VO, which will open new horizons for accurate local treatment, including drug infusion and surgical interventions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Fuzzy Mobile-Robot Positioning in Intelligent Spaces Using Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    David Herrero

    2011-11-01

    Full Text Available This work presents the development and experimental evaluation of a method based on fuzzy logic to locate mobile robots in an Intelligent Space using Wireless Sensor Networks (WSNs. The problem consists of locating a mobile node using only inter-node range measurements, which are estimated by radio frequency signal strength attenuation. The sensor model of these measurements is very noisy and unreliable. The proposed method makes use of fuzzy logic for modeling and dealing with such uncertain information. Besides, the proposed approach is compared with a probabilistic technique showing that the fuzzy approach is able to handle highly uncertain situations that are difficult to manage by well-known localization methods.

  3. An Adaptive Connectivity-based Centroid Algorithm for Node Positioning in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Aries Pratiarso

    2015-06-01

    Full Text Available In wireless sensor network applications, the position of nodes is randomly distributed following the contour of the observation area. A simple solution without any measurement tools is provided by range-free method. However, this method yields the coarse estimating position of the nodes. In this paper, we propose Adaptive Connectivity-based (ACC algorithm. This algorithm is a combination of Centroid as range-free based algorithm, and hop-based connectivity algorithm. Nodes have a possibility to estimate their own position based on the connectivity level between them and their reference nodes. Each node divides its communication range into several regions where each of them has a certain weight depends on the received signal strength. The weighted value is used to obtain the estimated position of nodes. Simulation result shows that the proposed algorithm has up to 3 meter error of estimated position on 100x100 square meter observation area, and up to 3 hop counts for 80 meters' communication range. The proposed algorithm performs an average error positioning up to 10 meters better than Weighted Centroid algorithm. Keywords: adaptive, connectivity, centroid, range-free.

  4. Energy Harvesting Hybrid Acoustic-Optical Underwater Wireless Sensor Networks Localization

    KAUST Repository

    Saeed, Nasir

    2017-12-26

    Underwater wireless technologies demand to transmit at higher data rate for ocean exploration. Currently, large coverage is achieved by acoustic sensor networks with low data rate, high cost, high latency, high power consumption, and negative impact on marine mammals. Meanwhile, optical communication for underwater networks has the advantage of the higher data rate albeit for limited communication distances. Moreover, energy consumption is another major problem for underwater sensor networks, due to limited battery power and difficulty in replacing or recharging the battery of a sensor node. The ultimate solution to this problem is to add energy harvesting capability to the acoustic-optical sensor nodes. Localization of underwater sensor networks is of utmost importance because the data collected from underwater sensor nodes is useful only if the location of the nodes is known. Therefore, a novel localization technique for energy harvesting hybrid acoustic-optical underwater wireless sensor networks (AO-UWSNs) is proposed. AO-UWSN employs optical communication for higher data rate at a short transmission distance and employs acoustic communication for low data rate and long transmission distance. A hybrid received signal strength (RSS) based localization technique is proposed to localize the nodes in AO-UWSNs. The proposed technique combines the noisy RSS based measurements from acoustic communication and optical communication and estimates the final locations of acoustic-optical sensor nodes. A weighted multiple observations paradigm is proposed for hybrid estimated distances to suppress the noisy observations and give more importance to the accurate observations. Furthermore, the closed form solution for Cramer-Rao lower bound (CRLB) is derived for localization accuracy of the proposed technique.

  5. Energy Harvesting Hybrid Acoustic-Optical Underwater Wireless Sensor Networks Localization

    Directory of Open Access Journals (Sweden)

    Nasir Saeed

    2017-12-01

    Full Text Available Underwater wireless technologies demand to transmit at higher data rate for ocean exploration. Currently, large coverage is achieved by acoustic sensor networks with low data rate, high cost, high latency, high power consumption, and negative impact on marine mammals. Meanwhile, optical communication for underwater networks has the advantage of the higher data rate albeit for limited communication distances. Moreover, energy consumption is another major problem for underwater sensor networks, due to limited battery power and difficulty in replacing or recharging the battery of a sensor node. The ultimate solution to this problem is to add energy harvesting capability to the acoustic-optical sensor nodes. Localization of underwater sensor networks is of utmost importance because the data collected from underwater sensor nodes is useful only if the location of the nodes is known. Therefore, a novel localization technique for energy harvesting hybrid acoustic-optical underwater wireless sensor networks (AO-UWSNs is proposed. AO-UWSN employs optical communication for higher data rate at a short transmission distance and employs acoustic communication for low data rate and long transmission distance. A hybrid received signal strength (RSS based localization technique is proposed to localize the nodes in AO-UWSNs. The proposed technique combines the noisy RSS based measurements from acoustic communication and optical communication and estimates the final locations of acoustic-optical sensor nodes. A weighted multiple observations paradigm is proposed for hybrid estimated distances to suppress the noisy observations and give more importance to the accurate observations. Furthermore, the closed form solution for Cramer-Rao lower bound (CRLB is derived for localization accuracy of the proposed technique.

  6. Energy Harvesting Hybrid Acoustic-Optical Underwater Wireless Sensor Networks Localization.

    Science.gov (United States)

    Saeed, Nasir; Celik, Abdulkadir; Al-Naffouri, Tareq Y; Alouini, Mohamed-Slim

    2017-12-26

    Underwater wireless technologies demand to transmit at higher data rate for ocean exploration. Currently, large coverage is achieved by acoustic sensor networks with low data rate, high cost, high latency, high power consumption, and negative impact on marine mammals. Meanwhile, optical communication for underwater networks has the advantage of the higher data rate albeit for limited communication distances. Moreover, energy consumption is another major problem for underwater sensor networks, due to limited battery power and difficulty in replacing or recharging the battery of a sensor node. The ultimate solution to this problem is to add energy harvesting capability to the acoustic-optical sensor nodes. Localization of underwater sensor networks is of utmost importance because the data collected from underwater sensor nodes is useful only if the location of the nodes is known. Therefore, a novel localization technique for energy harvesting hybrid acoustic-optical underwater wireless sensor networks (AO-UWSNs) is proposed. AO-UWSN employs optical communication for higher data rate at a short transmission distance and employs acoustic communication for low data rate and long transmission distance. A hybrid received signal strength (RSS) based localization technique is proposed to localize the nodes in AO-UWSNs. The proposed technique combines the noisy RSS based measurements from acoustic communication and optical communication and estimates the final locations of acoustic-optical sensor nodes. A weighted multiple observations paradigm is proposed for hybrid estimated distances to suppress the noisy observations and give more importance to the accurate observations. Furthermore, the closed form solution for Cramer-Rao lower bound (CRLB) is derived for localization accuracy of the proposed technique.

  7. Hybrid swarm intelligence optimization approach for optimal data storage position identification in wireless sensor networks.

    Science.gov (United States)

    Mohanasundaram, Ranganathan; Periasamy, Pappampalayam Sanmugam

    2015-01-01

    The current high profile debate with regard to data storage and its growth have become strategic task in the world of networking. It mainly depends on the sensor nodes called producers, base stations, and also the consumers (users and sensor nodes) to retrieve and use the data. The main concern dealt here is to find an optimal data storage position in wireless sensor networks. The works that have been carried out earlier did not utilize swarm intelligence based optimization approaches to find the optimal data storage positions. To achieve this goal, an efficient swam intelligence approach is used to choose suitable positions for a storage node. Thus, hybrid particle swarm optimization algorithm has been used to find the suitable positions for storage nodes while the total energy cost of data transmission is minimized. Clustering-based distributed data storage is utilized to solve clustering problem using fuzzy-C-means algorithm. This research work also considers the data rates and locations of multiple producers and consumers to find optimal data storage positions. The algorithm is implemented in a network simulator and the experimental results show that the proposed clustering and swarm intelligence based ODS strategy is more effective than the earlier approaches.

  8. Matrix Completion Optimization for Localization in Wireless Sensor Networks for Intelligent IoT

    Directory of Open Access Journals (Sweden)

    Thu L. N. Nguyen

    2016-05-01

    Full Text Available Localization in wireless sensor networks (WSNs is one of the primary functions of the intelligent Internet of Things (IoT that offers automatically discoverable services, while the localization accuracy is a key issue to evaluate the quality of those services. In this paper, we develop a framework to solve the Euclidean distance matrix completion problem, which is an important technical problem for distance-based localization in WSNs. The sensor network localization problem is described as a low-rank dimensional Euclidean distance completion problem with known nodes. The task is to find the sensor locations through recovery of missing entries of a squared distance matrix when the dimension of the data is small compared to the number of data points. We solve a relaxation optimization problem using a modification of Newton’s method, where the cost function depends on the squared distance matrix. The solution obtained in our scheme achieves a lower complexity and can perform better if we use it as an initial guess for an interactive local search of other higher precision localization scheme. Simulation results show the effectiveness of our approach.

  9. Dynamic Fuzzy-Logic Based Path Planning for Mobility-Assisted Localization in Wireless Sensor Networks.

    Science.gov (United States)

    Alomari, Abdullah; Phillips, William; Aslam, Nauman; Comeau, Frank

    2017-08-18

    Mobile anchor path planning techniques have provided as an alternative option for node localization in wireless sensor networks (WSNs). In such context, path planning is a movement pattern where a mobile anchor node's movement is designed in order to achieve a maximum localization ratio possible with a minimum error rate. Typically, the mobility path planning is designed in advance, which is applicable when the mobile anchor has sufficient sources of energy and time. However, when the mobility movement is restricted or limited, a dynamic path planning design is needed. This paper proposes a novel distributed range-free movement mechanism for mobility-assisted localization in WSNs when the mobile anchor's movement is limited. The designed movement is formed in real-time pattern using a fuzzy-logic approach based on the information received from the network and the nodes' deployment. Our proposed model, Fuzzy-Logic based Path Planning for mobile anchor-assisted Localization in WSNs (FLPPL), offers superior results in several metrics including both localization accuracy and localization ratio in comparison to other similar works.

  10. A New Three-Dimensional Indoor Positioning Mechanism Based on Wireless LAN

    Directory of Open Access Journals (Sweden)

    Jiujun Cheng

    2014-01-01

    Full Text Available The researches on two-dimensional indoor positioning based on wireless LAN and the location fingerprint methods have become mature, but in the actual indoor positioning situation, users are also concerned about the height where they stand. Due to the expansion of the range of three-dimensional indoor positioning, more features must be needed to describe the location fingerprint. Directly using a machine learning algorithm will result in the reduced ability of classification. To solve this problem, in this paper, a “divide and conquer” strategy is adopted; that is, first through k-medoids algorithm the three-dimensional location space is clustered into a number of service areas, and then a multicategory SVM with less features is created for each service area for further positioning. Our experiment shows that the error distance resolution of the approach with k-medoids algorithm and multicategory SVM is higher than that of the approach only with SVM, and the former can effectively decrease the “crazy prediction.”

  11. Intelligent Local Avoided Collision (iLAC) MAC Protocol for Very High Speed Wireless Network

    Science.gov (United States)

    Hieu, Dinh Chi; Masuda, Akeo; Rabarijaona, Verotiana Hanitriniala; Shimamoto, Shigeru

    Future wireless communication systems aim at very high data rates. As the medium access control (MAC) protocol plays the central role in determining the overall performance of the wireless system, designing a suitable MAC protocol is critical to fully exploit the benefit of high speed transmission that the physical layer (PHY) offers. In the latest 802.11n standard [2], the problem of long overhead has been addressed adequately but the issue of excessive colliding transmissions, especially in congested situation, remains untouched. The procedure of setting the backoff value is the heart of the 802.11 distributed coordination function (DCF) to avoid collision in which each station makes its own decision on how to avoid collision in the next transmission. However, collision avoidance is a problem that can not be solved by a single station. In this paper, we introduce a new MAC protocol called Intelligent Local Avoided Collision (iLAC) that redefines individual rationality in choosing the backoff counter value to avoid a colliding transmission. The distinguishing feature of iLAC is that it fundamentally changes this decision making process from collision avoidance to collaborative collision prevention. As a result, stations can avoid colliding transmissions with much greater precision. Analytical solution confirms the validity of this proposal and simulation results show that the proposed algorithm outperforms the conventional algorithms by a large margin.

  12. The Indoor Localization and Tracking Estimation Method of Mobile Targets in Three-Dimensional Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Zixi Jia

    2015-11-01

    Full Text Available Indoor localization is a significant research area in wireless sensor networks (WSNs. Generally, the nodes of WSNs are deployed in the same plane, i.e., the floor, as the target to be positioned, which causes the sensing signal to be influenced or even blocked by unpredictable obstacles, like furniture. However, a 3D system, like Cricket, can reduce the negative impact of obstacles to the maximum extent and guarantee the sensing signal transmission by using the line of sight (LOS. However, most of the traditional localization methods are not available for the new deployment mode. In this paper, we propose the self-localization of beacons method based on the Cayley–Menger determinant, which can determine the positions of beacons stuck in the ceiling; and differential sensitivity analysis (DSA is also applied to eliminate measurement errors in measurement data fusion. Then, the calibration of beacons scheme is proposed to further refine the locations of beacons by the mobile robot. According to the robot’s motion model based on dead reckoning, which is the process of determining one’s current position, we employ the H ∞ filter and the strong tracking filter (STF to calibrate the rough locations, respectively. Lastly, the optimal node selection scheme based on geometric dilution precision (GDOP is presented here, which is able to pick the group of beacons with the minimum GDOP from all of the beacons. Then, we propose the GDOP-based weighting estimation method (GWEM to associate redundant information with the position of the target. To verify the proposed methods in the paper, we design and conduct a simulation and an experiment in an indoor setting. Compared to EKF and the H ∞ filter, the adopted STF method can more effectively calibrate the locations of beacons; GWEM can provide centimeter-level precision in 3D environments by using the combination of beacons that minimizes GDOP.

  13. A Novel Enhanced Positioning Trilateration Algorithm Implemented for Medical Implant In-Body Localization

    Directory of Open Access Journals (Sweden)

    Peter Brida

    2013-01-01

    Full Text Available Medical implants based on wireless communication will play crucial role in healthcare systems. Some applications need to know the exact position of each implant. RF positioning seems to be an effective approach for implant localization. The two most common positioning data typically used for RF positioning are received signal strength and time of flight of a radio signal between transmitter and receivers (medical implant and network of reference devices with known position. This leads to positioning methods: received signal strength (RSS and time of arrival (ToA. Both methods are based on trilateration. Used positioning data are very important, but the positioning algorithm which estimates the implant position is important as well. In this paper, the proposal of novel algorithm for trilateration is presented. The proposed algorithm improves the quality of basic trilateration algorithms with the same quality of measured positioning data. It is called Enhanced Positioning Trilateration Algorithm (EPTA. The proposed algorithm can be divided into two phases. The first phase is focused on the selection of the most suitable sensors for position estimation. The goal of the second one lies in the positioning accuracy improving by adaptive algorithm. Finally, we provide performance analysis of the proposed algorithm by computer simulations.

  14. Local positioning systems in (game) sports.

    Science.gov (United States)

    Leser, Roland; Baca, Arnold; Ogris, Georg

    2011-01-01

    Position data of players and athletes are widely used in sports performance analysis for measuring the amounts of physical activities as well as for tactical assessments in game sports. However, positioning sensing systems are applied in sports as tools to gain objective information of sports behavior rather than as components of intelligent spaces (IS). The paper outlines the idea of IS for the sports context with special focus to game sports and how intelligent sports feedback systems can benefit from IS. Henceforth, the most common location sensing techniques used in sports and their practical application are reviewed, as location is among the most important enabling techniques for IS. Furthermore, the article exemplifies the idea of IS in sports on two applications.

  15. Local Positioning Systems in (Game) Sports

    Science.gov (United States)

    Leser, Roland; Baca, Arnold; Ogris, Georg

    2011-01-01

    Position data of players and athletes are widely used in sports performance analysis for measuring the amounts of physical activities as well as for tactical assessments in game sports. However, positioning sensing systems are applied in sports as tools to gain objective information of sports behavior rather than as components of intelligent spaces (IS). The paper outlines the idea of IS for the sports context with special focus to game sports and how intelligent sports feedback systems can benefit from IS. Henceforth, the most common location sensing techniques used in sports and their practical application are reviewed, as location is among the most important enabling techniques for IS. Furthermore, the article exemplifies the idea of IS in sports on two applications. PMID:22163725

  16. An efficient multi-carrier position-based packet forwarding protocol for wireless sensor networks

    KAUST Repository

    Bader, Ahmed

    2012-01-01

    Beaconless position-based forwarding protocols have recently evolved as a promising solution for packet forwarding in wireless sensor networks. However, as the node density grows, the overhead incurred in the process of relay selection grows significantly. As such, end-to-end performance in terms of energy and latency is adversely impacted. With the motivation of developing a packet forwarding mechanism that is tolerant to variation in node density, an alternative position-based protocol is proposed in this paper. In contrast to existing beaconless protocols, the proposed protocol is designed such that it eliminates the need for potential relays to undergo a relay selection process. Rather, any eligible relay may decide to forward the packet ahead, thus significantly reducing the underlying overhead. The operation of the proposed protocol is empowered by exploiting favorable features of orthogonal frequency division multiplexing (OFDM) at the physical layer. The end-to-end performance of the proposed protocol is evaluated against existing beaconless position-based protocols analytically and as well by means of simulations. The proposed protocol is demonstrated in this paper to be more efficient. In particular, it is shown that for the same amount of energy the proposed protocol transports one bit from source to destination much quicker. © 2012 IEEE.

  17. Wireless online position monitoring of manual valve types for plant configuration management in nuclear power plants

    International Nuclear Information System (INIS)

    Agarwal, Vivek; Buttles, John W.; Beaty, Lawrence H.; Naser, Joseph; Hallbert, Bruce P.

    2016-01-01

    In the current competitive energy market, the nuclear industry is committed to lower the operations and maintenance cost; increase productivity and efficiency while maintaining safe and reliable operation. The present operating model of nuclear power plants is dependent on large technical staffs that put the nuclear industry at long-term economic disadvantage. Technology can play a key role in nuclear power plant configuration management in offsetting labor costs by automating manually performed plant activities. The technology being developed, tested, and demonstrated in this paper will enable the continued safe operation of today’s fleet of light water reactors by providing the technical means to monitor components in plants today that are only routinely monitored through manual activities. The wireless enabled valve position indicators that are the subject of this paper are able to provide a valid position indication available continuously, rather than only periodically. As a result, a real-time (online) availability of valve positions using an affordable technologies are vital to plant configuration when compared with long-term labor rates, and provide information that can be used for a variety of plant engineering, maintenance, and management applications.

  18. Subjective Audio Quality over a Secure IEEE 802.11n Draft 2.0 Wireless Local Area Network

    Science.gov (United States)

    2009-03-01

    generated by a G.711 codec and transmission over an IEEE 802.11n draft 2.0 wireless local area network (WLAN). Decline in audio quality due to additional...6 2.5 Real-Time Transport Protocol ...................................................................................8 2.6 Audio Codecs ...Page 1. VoIP Audio Codec Data Rates and Typical MOS

  19. A Survey of Sound Source Localization Methods in Wireless Acoustic Sensor Networks

    Directory of Open Access Journals (Sweden)

    Maximo Cobos

    2017-01-01

    Full Text Available Wireless acoustic sensor networks (WASNs are formed by a distributed group of acoustic-sensing devices featuring audio playing and recording capabilities. Current mobile computing platforms offer great possibilities for the design of audio-related applications involving acoustic-sensing nodes. In this context, acoustic source localization is one of the application domains that have attracted the most attention of the research community along the last decades. In general terms, the localization of acoustic sources can be achieved by studying energy and temporal and/or directional features from the incoming sound at different microphones and using a suitable model that relates those features with the spatial location of the source (or sources of interest. This paper reviews common approaches for source localization in WASNs that are focused on different types of acoustic features, namely, the energy of the incoming signals, their time of arrival (TOA or time difference of arrival (TDOA, the direction of arrival (DOA, and the steered response power (SRP resulting from combining multiple microphone signals. Additionally, we discuss methods not only aimed at localizing acoustic sources but also designed to locate the nodes themselves in the network. Finally, we discuss current challenges and frontiers in this field.

  20. An Efficient and Self-Adapting Localization in Static Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Wei Dong

    2009-08-01

    Full Text Available Localization is one of the most important subjects in Wireless Sensor Networks (WSNs. To reduce the number of beacons and adopt probabilistic methods, some particle filter-based mobile beacon-assisted localization approaches have been proposed, such as Mobile Beacon-assisted Localization (MBL, Adapting MBL (A-MBL, and the method proposed by Hang et al. Some new significant problems arise in these approaches, however. The first question is which probability distribution should be selected as the dynamic model in the prediction stage. The second is whether the unknown node adopts neighbors’ observation in the update stage. The third is how to find a self-adapting mechanism to achieve more flexibility in the adapting stage. In this paper, we give the theoretical analysis and experimental evaluations to suggest which probability distribution in the dynamic model should be adopted to improve the efficiency in the prediction stage. We also give the condition for whether the unknown node should use the observations from its neighbors to improve the accuracy. Finally, we propose a Self-Adapting Mobile Beacon-assisted Localization (SA-MBL approach to achieve more flexibility and achieve almost the same performance with A-MBL.

  1. A Wireless Sensor Network with Soft Computing Localization Techniques for Track Cycling Applications

    Science.gov (United States)

    Gharghan, Sadik Kamel; Nordin, Rosdiadee; Ismail, Mahamod

    2016-01-01

    In this paper, we propose two soft computing localization techniques for wireless sensor networks (WSNs). The two techniques, Neural Fuzzy Inference System (ANFIS) and Artificial Neural Network (ANN), focus on a range-based localization method which relies on the measurement of the received signal strength indicator (RSSI) from the three ZigBee anchor nodes distributed throughout the track cycling field. The soft computing techniques aim to estimate the distance between bicycles moving on the cycle track for outdoor and indoor velodromes. In the first approach the ANFIS was considered, whereas in the second approach the ANN was hybridized individually with three optimization algorithms, namely Particle Swarm Optimization (PSO), Gravitational Search Algorithm (GSA), and Backtracking Search Algorithm (BSA). The results revealed that the hybrid GSA-ANN outperforms the other methods adopted in this paper in terms of accuracy localization and distance estimation accuracy. The hybrid GSA-ANN achieves a mean absolute distance estimation error of 0.02 m and 0.2 m for outdoor and indoor velodromes, respectively. PMID:27509495

  2. A Wireless Sensor Network with Soft Computing Localization Techniques for Track Cycling Applications

    Directory of Open Access Journals (Sweden)

    Sadik Kamel Gharghan

    2016-08-01

    Full Text Available In this paper, we propose two soft computing localization techniques for wireless sensor networks (WSNs. The two techniques, Neural Fuzzy Inference System (ANFIS and Artificial Neural Network (ANN, focus on a range-based localization method which relies on the measurement of the received signal strength indicator (RSSI from the three ZigBee anchor nodes distributed throughout the track cycling field. The soft computing techniques aim to estimate the distance between bicycles moving on the cycle track for outdoor and indoor velodromes. In the first approach the ANFIS was considered, whereas in the second approach the ANN was hybridized individually with three optimization algorithms, namely Particle Swarm Optimization (PSO, Gravitational Search Algorithm (GSA, and Backtracking Search Algorithm (BSA. The results revealed that the hybrid GSA-ANN outperforms the other methods adopted in this paper in terms of accuracy localization and distance estimation accuracy. The hybrid GSA-ANN achieves a mean absolute distance estimation error of 0.02 m and 0.2 m for outdoor and indoor velodromes, respectively.

  3. Differential Amplitude Pulse-Position Modulation for Indoor Wireless Optical Communications

    Directory of Open Access Journals (Sweden)

    Sethakaset Ubolthip

    2005-01-01

    Full Text Available We propose a novel differential amplitude pulse-position modulation (DAPPM for indoor optical wireless communications. DAPPM yields advantages over PPM, DPPM, and DH-PIM in terms of bandwidth requirements, capacity, and peak-to-average power ratio (PAPR. The performance of a DAPPM system with an unequalized receiver is examined over nondispersive and dispersive channels. DAPPM can provide better bandwidth and/or power efficiency than PAM, PPM, DPPM, and DH-PIM depending on the number of amplitude levels and the maximum length of a symbol. We also show that, given the same maximum length, DAPPM has better bandwidth efficiency but requires about and more power than PPM and DPPM, respectively, at high bit rates over a dispersive channel. Conversely, DAPPM requires less power than DH-PIM . When the number of bits per symbol is the same, PAM requires more power, and DH-PIM less power, than DAPPM. Finally, it is shown that the performance of DAPPM can be improved with MLSD, chip-rate DFE, and multichip-rate DFE.

  4. An Autonomous Distributed Fault-Tolerant Local Positioning System

    Science.gov (United States)

    Malekpour, Mahyar R.

    2017-01-01

    We describe a fault-tolerant, GPS-independent (Global Positioning System) distributed autonomous positioning system for static/mobile objects and present solutions for providing highly-accurate geo-location data for the static/mobile objects in dynamic environments. The reliability and accuracy of a positioning system fundamentally depends on two factors; its timeliness in broadcasting signals and the knowledge of its geometry, i.e., locations and distances of the beacons. Existing distributed positioning systems either synchronize to a common external source like GPS or establish their own time synchrony using a scheme similar to a master-slave by designating a particular beacon as the master and other beacons synchronize to it, resulting in a single point of failure. Another drawback of existing positioning systems is their lack of addressing various fault manifestations, in particular, communication link failures, which, as in wireless networks, are increasingly dominating the process failures and are typically transient and mobile, in the sense that they typically affect different messages to/from different processes over time.

  5. Signal strength based localization and path-loss exponent self-estimation in wireless networks

    NARCIS (Netherlands)

    Hu, Y.

    2017-01-01

    Wireless communications and networking are gradually permeating our life and substantially influencing every corner of this world. Wireless devices, particularly
    those of small size, will take part in this trend more widely, efficiently, seamlessly and smartly. Techniques requiring only limited

  6. Local labor unions' positions on worksite tobacco control.

    Science.gov (United States)

    Sorensen, G; Stoddard, A M; Youngstrom, R; Emmons, K; Barbeau, E; Khorasanizadeh, F; Levenstein, C

    2000-01-01

    OBJECTIVES: This report describes local unions' positions on tobacco control initiatives and factors related to these positions. METHODS: A national random sample of local union leaders was surveyed by telephone. RESULTS: Forty-eight percent of local unions supported worksite smoking bans or restrictions, and only 8% opposed both a ban and a restriction. CONCLUSIONS: Support for tobacco control initiatives among local unions was higher than might be expected on the basis of previous evidence. Engaging unions in smoking policy formation is likely to contribute to the larger public health goal of reducing smoking and exposure to second-hand smoke among workers. PMID:10754979

  7. A novel cooperative localization algorithm using enhanced particle filter technique in maritime search and rescue wireless sensor network.

    Science.gov (United States)

    Wu, Huafeng; Mei, Xiaojun; Chen, Xinqiang; Li, Junjun; Wang, Jun; Mohapatra, Prasant

    2017-09-29

    Maritime search and rescue (MSR) play a significant role in Safety of Life at Sea (SOLAS). However, it suffers from scenarios that the measurement information is inaccurate due to wave shadow effect when utilizing wireless Sensor Network (WSN) technology in MSR. In this paper, we develop a Novel Cooperative Localization Algorithm (NCLA) in MSR by using an enhanced particle filter method to reduce measurement errors on observation model caused by wave shadow effect. First, we take into account the mobility of nodes at sea to develop a motion model-Lagrangian model. Furthermore, we introduce both state model and observation model to constitute a system model for particle filter (PF). To address the impact of the wave shadow effect on the observation model, we develop an optimal parameter derived by Kullback-Leibler divergence (KLD) to mitigate the error. After the optimal parameter is acquired, an improved likelihood function is presented. Finally, the estimated position is acquired. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  8. OdoCapsule: next-generation wireless capsule endoscopy with accurate lesion localization and video stabilization capabilities.

    Science.gov (United States)

    Karargyris, Alexandros; Koulaouzidis, Anastastios

    2015-01-01

    In this paper, we propose a platform to achieve accurate localization of small-bowel lesions and endoscopic video stabilization in wireless capsule endoscopy. Current research modules rely on the use of external magnetic fields and triangulation methods to calculate the position vector of the capsule, leading to considerable error margins. Our platform, entitled OdoCapsule (a synthesis of the words Odometer and Capsule), provides real-time distance information from the point of duodenal entry to the point of exit from the small bowel. To achieve this, OdoCapsule is equipped with three miniature legs. Each leg carries a soft rubber wheel, which is made with human-compliant material. These legs are extendable and retractable thanks to a micromotor and three custom-made torsion springs. The wheels are specifically designed to function as microodometers: each rotation they perform is registered. Hence, the covered distance is measured accurately in real time. Furthermore, with its legs fully extended, OdoCapsule can stabilize itself inside the small-bowel lumen thus offering smoother video capture and better image processing. Recent ex vivo testing of this concept, using porcine small bowel and a commercially available (custom-modified) capsule endoscope, has proved its viability.

  9. Probabilistic Localization and Tracking of Malicious Insiders Using Hyperbolic Position Bounding in Vehicular Networks

    Directory of Open Access Journals (Sweden)

    Laurendeau Christine

    2009-01-01

    Full Text Available A malicious insider in a wireless network may carry out a number of devastating attacks without fear of retribution, since the messages it broadcasts are authenticated with valid credentials such as a digital signature. In attributing an attack message to its perpetrator by localizing the signal source, we can make no presumptions regarding the type of radio equipment used by a malicious transmitter, including the transmitting power utilized to carry out an exploit. Hyperbolic position bounding (HPB provides a mechanism to probabilistically estimate the candidate location of an attack message's originator using received signal strength (RSS reports, without assuming knowledge of the transmitting power. We specialize the applicability of HPB into the realm of vehicular networks and provide alternate HPB algorithms to improve localization precision and computational efficiency. We extend HPB for tracking the consecutive locations of a mobile attacker. We evaluate the localization and tracking performance of HPB in a vehicular scenario featuring a variable number of receivers and a known navigational layout. We find that HPB can position a transmitting device within stipulated guidelines for emergency services localization accuracy.

  10. Determining the localization of premolar zenith positions according ...

    African Journals Online (AJOL)

    Determining the localization of premolar zenith positions according to the gingival line. ... Conclusions: The present study results showed that GZs of FPM and SPM teeth for both left and right sight was coronally located according to ZL. Key words: Gingival aesthetics, gingival localization, maxillary premolars ...

  11. The Enhanced Workflow and Efficiency of the Wireless Local Area Network (WLAN)-Based Direct Digital Radiography (DDR) Portable Radiography.

    Science.gov (United States)

    Ngan, Tsz-Lung; Wong, Edward Ting-Hei; Ng, Kris Lap-Shun; Jeor, Patrick Kwok-Shing; Lo, Gladys Goh

    2015-06-01

    With the implementation of the PACS in the hospital, there is an increasing demand from the clinicians for immediate access and display of radiological images. Recently, our hospital has installed the first wireless local area network (WLAN)-based direct digital radiography (DDR) portable radiography system. The DDR portable radiography system allows wireless retrieval of modality worklist and wireless transmission of portable X-ray image on the console to the Picture Archiving and Communication System (PACS), via WLAN connection of wireless fidelity (Wi-Fi). The aim of this study was to analyze the workflow and performance between the WLAN-based DDR portable radiography system and the old practice using conventional portable X-ray machine with computed radiography (CR) system. A total of 190 portable chest X-ray examinations were evaluated and timed, using the conventional portable X-ray machine with CR from March to April of 2012 and using the new DDR portable radiography system on December of 2012 (n = 97 for old system and n = 93 for DDR portable system). The time interval of image becoming available to the PACS using the WLAN-based DDR portable radiography system was significantly shorter than that of the old practice using the conventional portable X-ray machine with CR (6.8 ± 2.6 min for DDR portable system; 23 ± 10.2 min for old system; p DDR portable radiography system can enhance the workflow of portable radiography by reduction of procedural steps.

  12. Radiofrequency Field Distribution Assessment in Indoor Areas Covered by Wireless Local Area Network

    Directory of Open Access Journals (Sweden)

    HELBET, R.

    2009-02-01

    Full Text Available Electromagnetic environment becomes day by day more congested. Radio communication systems in the short range are now part of everyday life, and there is a need to also assess the pollution level due to their emission if we take into account human health and protection. There is consistent scientific evidence that environmental electromagnetic field may cause undesirable biological effects or even health hazards. Present paper aims at giving a view on exposure level due to wireless local area networks (WLAN emission solely, as part of environmental radiofrequency pollution. Highly accurate measurements were made indoor by using a frequency-selective measurement system and identifying the correct settings for an error-minimum assessment. We focused on analysis of the electric flux density distribution inside a room, in the far field of the emitting antennas, in case of a single network communication channel. We analyze the influence the network configuration parameters have on the field level. Distance from the source and traffic rate are also important parameters that affect the exposure level. Our measurements indicate that in the immediate vicinity of the WLAN stations the average field may reach as much as 13% from the present accepted reference levels given in the human exposure standards.

  13. Achievable Throughput-Based MAC Layer Handoff in IEEE 802.11 Wireless Local Area Networks

    Directory of Open Access Journals (Sweden)

    Wu Haitao

    2009-01-01

    Full Text Available We propose a MAC layer handoff mechanism for IEEE 802.11 Wireless Local Area Networks (WLAN to give benefit to bandwidth-greedy applications at STAs. The proposed mechanism determines an optimal AP with the maximum achievable throughput rather than the best signal condition by estimating the AP's bandwidth with a new on-the-fly measurement method, Transient Frame Capture (TFC, and predicting the actual throughput could be achieved at STAs. Since the TFC is employed based on the promiscuous mode of WLAN NIC, STAs can avoid the service degradation through the current associated AP. In addition, the proposed mechanism is a client-only solution which does not require any modification of network protocol on APs. To evaluate the performance of the proposed mechanism, we develop an analytic model to estimate reliable and accurate bandwidth of the AP and demonstrate through testbed measurement with various experimental study methods. We also validate the fairness of the proposed mechanism through simulation studies.

  14. Wireless security in mobile health.

    Science.gov (United States)

    Osunmuyiwa, Olufolabi; Ulusoy, Ali Hakan

    2012-12-01

    Mobile health (m-health) is an extremely broad term that embraces mobile communication in the health sector and data packaging. The four broad categories of wireless networks are wireless personal area network, wireless metropolitan area network, wireless wide area network, and wireless local area network. Wireless local area network is the most notable of the wireless networking tools obtainable in the health sector. Transfer of delicate and critical information on radio frequencies should be secure, and the right to use must be meticulous. This article covers the business opportunities in m-health, threats faced by wireless networks in hospitals, and methods of mitigating these threats.

  15. Wireless Networks: New Meaning to Ubiquitous Computing.

    Science.gov (United States)

    Drew, Wilfred, Jr.

    2003-01-01

    Discusses the use of wireless technology in academic libraries. Topics include wireless networks; standards (IEEE 802.11); wired versus wireless; why libraries implement wireless technology; wireless local area networks (WLANs); WLAN security; examples of wireless use at Indiana State University and Morrisville College (New York); and useful…

  16. Secure Localization for Wireless Sensor Networks using Range-Independent Methods

    National Research Council Canada - National Science Library

    Lazos, Loukas; Poovendran, Radha

    2006-01-01

    Wireless Sensor Networks (WSNs) are envisioned to be integrated into our everyday lives, enabling a wealth of commercial applications such as environmental and habitat monitoring, disaster relief and emergency rescue operations...

  17. An Improved Approach for RSSI-Based only Calibration-Free Real-Time Indoor Localization on IEEE 802.11 and 802.15.4 Wireless Networks

    Directory of Open Access Journals (Sweden)

    Marco Passafiume

    2017-03-01

    Full Text Available Assuming a reliable and responsive spatial contextualization service is a must-have in IEEE 802.11 and 802.15.4 wireless networks, a suitable approach consists of the implementation of localization capabilities, as an additional application layer to the communication protocol stack. Considering the applicative scenario where satellite-based positioning applications are denied, such as indoor environments, and excluding data packet arrivals time measurements due to lack of time resolution, received signal strength indicator (RSSI measurements, obtained according to IEEE 802.11 and 802.15.4 data access technologies, are the unique data sources suitable for indoor geo-referencing using COTS devices. In the existing literature, many RSSI based localization systems are introduced and experimentally validated, nevertheless they require periodic calibrations and significant information fusion from different sensors that dramatically decrease overall systems reliability and their effective availability. This motivates the work presented in this paper, which introduces an approach for an RSSI-based calibration-free and real-time indoor localization. While switched-beam array-based hardware (compliant with IEEE 802.15.4 router functionality has already been presented by the author, the focus of this paper is the creation of an algorithmic layer for use with the pre-existing hardware capable to enable full localization and data contextualization over a standard 802.15.4 wireless sensor network using only RSSI information without the need of lengthy offline calibration phase. System validation reports the localization results in a typical indoor site, where the system has shown high accuracy, leading to a sub-metrical overall mean error and an almost 100% site coverage within 1 m localization error.

  18. An Improved Approach for RSSI-Based only Calibration-Free Real-Time Indoor Localization on IEEE 802.11 and 802.15.4 Wireless Networks.

    Science.gov (United States)

    Passafiume, Marco; Maddio, Stefano; Cidronali, Alessandro

    2017-03-29

    Assuming a reliable and responsive spatial contextualization service is a must-have in IEEE 802.11 and 802.15.4 wireless networks, a suitable approach consists of the implementation of localization capabilities, as an additional application layer to the communication protocol stack. Considering the applicative scenario where satellite-based positioning applications are denied, such as indoor environments, and excluding data packet arrivals time measurements due to lack of time resolution, received signal strength indicator (RSSI) measurements, obtained according to IEEE 802.11 and 802.15.4 data access technologies, are the unique data sources suitable for indoor geo-referencing using COTS devices. In the existing literature, many RSSI based localization systems are introduced and experimentally validated, nevertheless they require periodic calibrations and significant information fusion from different sensors that dramatically decrease overall systems reliability and their effective availability. This motivates the work presented in this paper, which introduces an approach for an RSSI-based calibration-free and real-time indoor localization. While switched-beam array-based hardware (compliant with IEEE 802.15.4 router functionality) has already been presented by the author, the focus of this paper is the creation of an algorithmic layer for use with the pre-existing hardware capable to enable full localization and data contextualization over a standard 802.15.4 wireless sensor network using only RSSI information without the need of lengthy offline calibration phase. System validation reports the localization results in a typical indoor site, where the system has shown high accuracy, leading to a sub-metrical overall mean error and an almost 100% site coverage within 1 m localization error.

  19. A Research of RSSI-AM Localization Algorithm Based on Data Encryption in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Wang Wei

    2014-07-01

    Full Text Available In practical application of wireless sensor networks, because of open environment, signal is easy to be attacked and traditional RSSI location technology produces errors. By analyzing the location modal of RSSI, this paper proposes a new encryption modulation algorithm: RSSI-AM, which is unlike most approaches. The location algorithm has the following advantages: simple calculation, strong security, powerful anti-interference ability and no hardware expansion required. Besides, the simulation experiment shows the location precision of ranging method based on RSSI-AM has obvious improvement compared with traditional algorithm. It can be used in the environment of wireless sensor network nodes with low cost and performance of hardware.

  20. Positive definite functions and dual pairs of locally convex spaces

    Directory of Open Access Journals (Sweden)

    Daniel Alpay

    2018-01-01

    Full Text Available Using pairs of locally convex topological vector spaces in duality and topologies defined by directed families of sets bounded with respect to the duality, we prove general factorization theorems and general dilation theorems for operator-valued positive definite functions.

  1. The modelling of a digital forensic readiness approach for wireless local area networks

    CSIR Research Space (South Africa)

    Ngobeni, S

    2012-06-01

    Full Text Available of cybercrime. WLAN digital forensics is seen as not only a response to cybercrime in wireless networks, but also a means to stem the increase of cybercrime in WLANs. The challenge in WLAN digital forensics is to intercept and preserve all the communications...

  2. Sound source localization using a low-cost wireless sensor network

    NARCIS (Netherlands)

    Leeuwen, van H. (Henk); Salomons, E.L. (Etto); Teeuw, W.B. (Wouter)

    2013-01-01

    In the GoGreen project an intelligent home that is able to identify inhabitants and events that take place is created. The location of sounds that are being produced is an important feature for the context awareness of this system. A a wireless solution that uses low-cost sensor nodes and

  3. Multiple wireless protocol advertising system, enabling automatic access selection and local services

    NARCIS (Netherlands)

    Houben, S.A.; Baken, N.; Herve, P.; Smets, R.

    2006-01-01

    We examined efficiency within wireless access options for mobile devices and discovered that a classic pitfall is revisited. As with the proliferation of services in incumbents’ portfolios, leading to a number of coexisting so-called ‘stove-pipes’, we see an isomorphic phenomenon evolving in

  4. A GPS-free passive acoustic localization scheme for underwater wireless sensor networks

    KAUST Repository

    Mirza, Mohammed

    2011-10-01

    Seaweb is an acoustic communication technology that enables communication between sensor nodes. Seaweb interconnects the underwater nodes through digital signal processing (DSP)-based modem by using acoustic links between the neighbouring sensors. In this paper, we design and investigate a global positioning system (GPS)-free passive localization protocol using seaweb technology. This protocol uses the range data and planar trigonometry to estimate the positions of the discovered nodes. We take into consideration the small displacement of sensor nodes due to watch circles and placement of sensor nodes on non-uniform underwater surface, for precise localization. Once the nodes are localized, we divide the whole network .eld into circular levels that minimizes the traf.c complexity and thereby increases the lifetime of the sensor network .eld. We then form the mesh network inside each of the circular levels that increases the reliability. The algorithm is designed in such a way that it overcomes the ambiguous nodes errata and re.ected paths and makes the algorithm more robust. The synthetic network geometries are so designed which can evaluate the algorithm in the presence of perfect or imperfect ranges or in case of incomplete data. A comparative study is made with the existing algorithms which proves our newly proposed algorithm to be more effective. © 2011 IEEE.

  5. Local differences in the position of the mental foramen.

    Science.gov (United States)

    Yeşilyurt, H; Aydinlioglu, A; Kavakli, A; Ekinci, N; Eroglu, C; Hacialiogullari, M; Diyarbakirli, S

    2008-02-01

    The mental foramen has been reported to vary in position in different ethnic groups. Repeated failures during injections and operative procedures involving the mental foramen suggest the presence of local differences in a given population. The aim of the present study was to investigate possible local differences of the mental foramen in Eastern Anatolian individuals in the Turkish population. The present investigation is based on the examination of 70 adult mandibles. The study consisted of three measurements, to include the relations of the mental foramen to the following: 1) the lower teeth; 2) the body of mandible; 3) the mandibular symphysis and posterior border of the ramus of the mandible. The most common position of the foramen was in line with the longitudinal axis of the second premolar tooth (relation IV), at the midpoint of the mandibular body height and at 1/3.5 of the distance from the mandibular symphysis to the posterior border of the ramus. Local differences of the mental foramen may occur in a population. Prior to surgery knowledge of the most common location of the foramen peculiar to a local population may enable effective mental block anaesthesia to be provided.

  6. Using the local positioning system based on Pulse Width Modulation ...

    African Journals Online (AJOL)

    Michael Horsfall

    submitted to the department of aeronautics of. Stanford university in partial fulfilment of the requirements for the degree of doctor of philosophy,. August, 2004. 6-“ Robotics-based location sensing for wireless. Ethernet” A. M. Ladd, K. E. Bekris, G. Marceau,. A. Rudys, D. S. Wallach, and L. E. Kavraki, In ACM. MobiCom, 2002.

  7. A Localization Method for Underwater Wireless Sensor Networks Based on Mobility Prediction and Particle Swarm Optimization Algorithms

    Directory of Open Access Journals (Sweden)

    Ying Zhang

    2016-02-01

    Full Text Available Due to their special environment, Underwater Wireless Sensor Networks (UWSNs are usually deployed over a large sea area and the nodes are usually floating. This results in a lower beacon node distribution density, a longer time for localization, and more energy consumption. Currently most of the localization algorithms in this field do not pay enough consideration on the mobility of the nodes. In this paper, by analyzing the mobility patterns of water near the seashore, a localization method for UWSNs based on a Mobility Prediction and a Particle Swarm Optimization algorithm (MP-PSO is proposed. In this method, the range-based PSO algorithm is used to locate the beacon nodes, and their velocities can be calculated. The velocity of an unknown node is calculated by using the spatial correlation of underwater object’s mobility, and then their locations can be predicted. The range-based PSO algorithm may cause considerable energy consumption and its computation complexity is a little bit high, nevertheless the number of beacon nodes is relatively smaller, so the calculation for the large number of unknown nodes is succinct, and this method can obviously decrease the energy consumption and time cost of localizing these mobile nodes. The simulation results indicate that this method has higher localization accuracy and better localization coverage rate compared with some other widely used localization methods in this field.

  8. A Localization Method for Underwater Wireless Sensor Networks Based on Mobility Prediction and Particle Swarm Optimization Algorithms.

    Science.gov (United States)

    Zhang, Ying; Liang, Jixing; Jiang, Shengming; Chen, Wei

    2016-02-06

    Due to their special environment, Underwater Wireless Sensor Networks (UWSNs) are usually deployed over a large sea area and the nodes are usually floating. This results in a lower beacon node distribution density, a longer time for localization, and more energy consumption. Currently most of the localization algorithms in this field do not pay enough consideration on the mobility of the nodes. In this paper, by analyzing the mobility patterns of water near the seashore, a localization method for UWSNs based on a Mobility Prediction and a Particle Swarm Optimization algorithm (MP-PSO) is proposed. In this method, the range-based PSO algorithm is used to locate the beacon nodes, and their velocities can be calculated. The velocity of an unknown node is calculated by using the spatial correlation of underwater object's mobility, and then their locations can be predicted. The range-based PSO algorithm may cause considerable energy consumption and its computation complexity is a little bit high, nevertheless the number of beacon nodes is relatively smaller, so the calculation for the large number of unknown nodes is succinct, and this method can obviously decrease the energy consumption and time cost of localizing these mobile nodes. The simulation results indicate that this method has higher localization accuracy and better localization coverage rate compared with some other widely used localization methods in this field.

  9. Local Magnetic Fields in Ferromagnetics Studied by Positive Muon Precession

    CERN Multimedia

    2002-01-01

    Positive muons are used to study local magnetic fields in different materials. A polarized muon beam is employed with energies of 30-50 MeV, and the muons are stopped in the target being studied. During its lifetime the muon will precess in the magnetic fields present, and after the decay of the muon the emitted positron is detected in plastic scintillators. The time and angle of the detected positron is used to calculate the magnetic field at the position of the muon in the sample. \\\\ \\\\ The detector system consists of plastic scintillators. Most of the measurements are made in an applied magnetic field. A dilution cryostat is used to produce temperatures down to well below $ 1 ^0 $ K. \\\\ \\\\ The present line of experiments concern mainly: \\item a)~~~~Local magnetism in the paramagnetic state of the Lave's phase type REAl$_{2} $ and RENi$_{2} $ systems ~~~where RE is a rare-earth ion. \\item b)~~~~Local magnetic fields and critical behaviour of the magnetism in Gd metal. \\item c)~~~~Investigation of flux exclu...

  10. Extending Wireless Broadband Network Architectures with Home Gateways, Localization, and Physical Environment Surveillance

    DEFF Research Database (Denmark)

    Jelling Kristoffersen, Kåre; Kjærgaard, Mikkel Baun; Chen, Jianjun

    2005-01-01

    Adding content is seen as the next important step in the development and deployment of broadband networks. This paper proposes three different ways of adding content to wireless broadband networks. First, the home gateway is presented as the focal point for delivery of digital services to future...... homes. It must bridge across the most prevalent standard protocols for data, video, telephony and telemetry, and must be able to automatically discover new devices in a residence and allow over the air/wire provisioning, billing, management and aggregation of new services from multiple service providers...

  11. Tunable locally-optimal geographical forwarding in wireless sensor networks with sleep-wake cycling nodes

    OpenAIRE

    Naveen, K. P.; Kumar, A.

    2009-01-01

    We consider a wireless sensor network whose main function is to detect certain infrequent alarm events, and to forward alarm packets to a base station, using geographical forwarding. The nodes know their locations, and they sleep-wake cycle, waking up periodically but not synchronously. In this situation, when a node has a packet to forward to the sink, there is a trade-off between how long this node waits for a suitable neighbor to wake up and the progress the packet makes towards the sink o...

  12. The Localized Discovery and Recovery for Query Packet Losses in Wireless Sensor Networks with Distributed Detector Clusters

    Directory of Open Access Journals (Sweden)

    Ryu Miura

    2013-06-01

    Full Text Available An essential application of wireless sensor networks is to successfully respond to user queries. Query packet losses occur in the query dissemination due to wireless communication problems such as interference, multipath fading, packet collisions, etc. The losses of query messages at sensor nodes result in the failure of sensor nodes reporting the requested data. Hence, the reliable and successful dissemination of query messages to sensor nodes is a non-trivial problem. The target of this paper is to enable highly successful query delivery to sensor nodes by localized and energy-efficient discovery, and recovery of query losses. We adopt local and collective cooperation among sensor nodes to increase the success rate of distributed discoveries and recoveries. To enable the scalability in the operations of discoveries and recoveries, we employ a distributed name resolution mechanism at each sensor node to allow sensor nodes to self-detect the correlated queries and query losses, and then efficiently locally respond to the query losses. We prove that the collective discovery of query losses has a high impact on the success of query dissemination and reveal that scalability can be achieved by using the proposed approach. We further study the novel features of the cooperation and competition in the collective recovery at PHY and MAC layers, and show that the appropriate number of detectors can achieve optimal successful recovery rate. We evaluate the proposed approach with both mathematical analyses and computer simulations. The proposed approach enables a high rate of successful delivery of query messages and it results in short route lengths to recover from query losses. The proposed approach is scalable and operates in a fully distributed manner.

  13. Technical Training Seminar: Laser Trackers: the Local Positioning Technology (LPT)

    CERN Multimedia

    Davide Vitè

    2005-01-01

    Friday 20 May from 10:00 to 16:00, Training Centre (bldg. 593) Laser Trackers: the Local Positioning Technology (LPT) Simon Moser, Michael Lettau, Achim Lupus, Niklaus Suter, Leica GEOSYSTEMS AG, Switzerland Laser trackers are used at CERN for different applications within the LHC Project. Leica Geosystems AG have been developing during the last four years the revolutionary Local Positioning Technology (LPT). Laser trackers are increasingly used to ensure accuracy of large fabrications, and alignment in the final assembly process. Competing portable Coordinate Measuring Machines (CMM) with articulated arms require a frequent repositioning, known to lead to a loss of accuracy and efficiency. Leica Geosystems developed armless solutions, the T-Probe and T-Scan, for use with its laser trackers. The combination of the tracker technology with photogrammetry is the base of LPT, enabling real time measurements with free hand-held devices, such as the T-Probe and T-Scan. T-Probe and T-Scan overcome the proble...

  14. Position and Orientation Insensitive Wireless Power Transmission for EnerCage-Homecage System.

    Science.gov (United States)

    Jia, Yaoyao; Mirbozorgi, S Abdollah; Wang, Zheyuan; Hsu, Chia-Chun; Madsen, Teresa E; Rainnie, Donald; Ghovanloo, Maysam

    2017-10-01

    We have developed a new headstage architecture as part of a smart experimental arena, known as the EnerCage-HC2 system, which automatically delivers stimulation and collects behavioral data over extended periods with minimal small animal subject handling or personnel intervention in a standard rodent homecage. Equipped with a four-coil inductive link, the EnerCage-HC2 system wirelessly powers the receiver (Rx) headstage, irrespective of the subject's location or head orientation, eliminating the need for tethering or carrying bulky batteries. On the transmitter (Tx) side, a driver coil, five high-quality (Q) factor segmented resonators at different heights and orientations, and a closed-loop Tx power controller create a homogeneous electromagnetic (EM) field within the homecage 3-D space, and compensate for drops in power transfer efficiency (PTE) due to Rx misalignments. The headstage is equipped with four small slanted resonators, each covering a range of head orientations with respect to the Tx resonators, which direct the EM field toward the load coil at the bottom of the headstage. Moreover, data links based on Wi-Fi, UART, and Bluetooth low energy are utilized to enables remote communication and control of the Rx. The PTE varies within 23.6%-33.3% and 6.7%-10.1% at headstage heights of 8 and 20 cm, respectively, while continuously delivering >40 mW to the Rx electronics even at 90° rotation. As a proof of EnerCage-HC2 functionality in vivo, a previously documented on-demand electrical stimulation of the globus pallidus, eliciting consistent head rotation, is demonstrated in three freely behaving rats.

  15. Hop-distance relationship analysis with quasi-UDG model for node localization in wireless sensor networks

    Directory of Open Access Journals (Sweden)

    Chen Ping

    2011-01-01

    Full Text Available Abstract In wireless sensor networks (WSNs, location information plays an important role in many fundamental services which includes geographic routing, target tracking, location-based coverage, topology control, and others. One promising approach in sensor network localization is the determination of location based on hop counts. A critical priori of this approach that directly influences the accuracy of location estimation is the hop-distance relationship. However, most of the related works on the hop-distance relationship assume the unit-disk graph (UDG model that is unrealistic in a practical scenario. In this paper, we formulate the hop-distance relationship for quasi-UDG model in WSNs where sensor nodes are randomly and independently deployed in a circular region based on a Poisson point process. Different from the UDG model, quasi-UDG model has the non-uniformity property for connectivity. We derive an approximated recursive expression for the probability of the hop count with a given geographic distance. The border effect and dependence problem are also taken into consideration. Furthermore, we give the expressions describing the distribution of distance with known hop counts for inner nodes and those suffered from the border effect where we discover the insignificance of the border effect. The analytical results are validated by simulations showing the accuracy of the employed approximation. Besides, we demonstrate the localization application of the formulated relationship and show the accuracy improvement in the WSN localization.

  16. Locating Damage Using Integrated Global-Local Approach with Wireless Sensing System and Single-Chip Impedance Measurement Device

    Directory of Open Access Journals (Sweden)

    Tzu-Hsuan Lin

    2014-01-01

    Full Text Available This study developed an integrated global-local approach for locating damage on building structures. A damage detection approach with a novel embedded frequency response function damage index (NEFDI was proposed and embedded in the Imote2.NET-based wireless structural health monitoring (SHM system to locate global damage. Local damage is then identified using an electromechanical impedance- (EMI- based damage detection method. The electromechanical impedance was measured using a single-chip impedance measurement device which has the advantages of small size, low cost, and portability. The feasibility of the proposed damage detection scheme was studied with reference to a numerical example of a six-storey shear plane frame structure and a small-scale experimental steel frame. Numerical and experimental analysis using the integrated global-local SHM approach reveals that, after NEFDI indicates the approximate location of a damaged area, the EMI-based damage detection approach can then identify the detailed damage location in the structure of the building.

  17. Locating damage using integrated global-local approach with wireless sensing system and single-chip impedance measurement device.

    Science.gov (United States)

    Lin, Tzu-Hsuan; Lu, Yung-Chi; Hung, Shih-Lin

    2014-01-01

    This study developed an integrated global-local approach for locating damage on building structures. A damage detection approach with a novel embedded frequency response function damage index (NEFDI) was proposed and embedded in the Imote2.NET-based wireless structural health monitoring (SHM) system to locate global damage. Local damage is then identified using an electromechanical impedance- (EMI-) based damage detection method. The electromechanical impedance was measured using a single-chip impedance measurement device which has the advantages of small size, low cost, and portability. The feasibility of the proposed damage detection scheme was studied with reference to a numerical example of a six-storey shear plane frame structure and a small-scale experimental steel frame. Numerical and experimental analysis using the integrated global-local SHM approach reveals that, after NEFDI indicates the approximate location of a damaged area, the EMI-based damage detection approach can then identify the detailed damage location in the structure of the building.

  18. Frame-Aggregated Link Adaptation Protocol for Next Generation Wireless Local Area Networks

    Directory of Open Access Journals (Sweden)

    Feng Kai-Ten

    2010-01-01

    Full Text Available The performance of wireless networks is affected by channel conditions. Link Adaptation techniques have been proposed to improve the degraded network performance by adjusting the design parameters, for example, the modulation and coding schemes, in order to adapt to the dynamically changing channel conditions. Furthermore, due to the advancement of the IEEE 802.11n standard, the network goodput can be enhanced with the exploitation of its frame aggregation schemes. However, none of the existing link adaption algorithms are designed to consider the feasible number of aggregated frames that should be utilized for channel-changing environments. In this paper, a frame-aggregated link adaptation (FALA protocol is proposed to dynamically adjust system parameters in order to improve the network goodput under varying channel conditions. For the purpose of maximizing network goodput, both the optimal frame payload size and the modulation and coding schemes are jointly obtained according to the signal-to-noise ratio under specific channel conditions. The performance evaluation is conducted and compared to the existing link adaption protocols via simulations. The simulation results show that the proposed FALA protocol can effectively increase the goodput performance compared to other baseline schemes, especially under dynamically-changing environments.

  19. Localized and Energy-Efficient Topology Control in Wireless Sensor Networks Using Fuzzy-Logic Control Approaches

    Directory of Open Access Journals (Sweden)

    Yuanjiang Huang

    2014-01-01

    Full Text Available The sensor nodes in the Wireless Sensor Networks (WSNs are prone to failures due to many reasons, for example, running out of battery or harsh environment deployment; therefore, the WSNs are expected to be able to maintain network connectivity and tolerate certain amount of node failures. By applying fuzzy-logic approach to control the network topology, this paper aims at improving the network connectivity and fault-tolerant capability in response to node failures, while taking into account that the control approach has to be localized and energy efficient. Two fuzzy controllers are proposed in this paper: one is Learning-based Fuzzy-logic Topology Control (LFTC, of which the fuzzy controller is learnt from a training data set; another one is Rules-based Fuzzy-logic Topology Control (RFTC, of which the fuzzy controller is obtained through designing if-then rules and membership functions. Both LFTC and RFTC do not rely on location information, and they are localized. Comparing them with other three representative algorithms (LTRT, List-based, and NONE through extensive simulations, our two proposed fuzzy controllers have been proved to be very energy efficient to achieve desired node degree and improve the network connectivity when sensor nodes run out of battery or are subject to random attacks.

  20. Local energy losses at positive and negative steps in subcritical ...

    African Journals Online (AJOL)

    Local energy losses occur when there is a transition in open channel flow. Even though local losses in subcritical open channel flow due to changes in channel width have been studied, to date no studies have been reported for losses due to changes in bed elevations. Steps are commonly used in engineering applications ...

  1. Time of Arrival Based on Chirp Pulses as a means to Perform Localization in IEEE 802.15.4a Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    NAUWELAERS, B.

    2010-05-01

    Full Text Available This paper introduces the technology Time of Arrival (TOA based on chirp pulses (according to IEEE 802.15.4a as a means to perform localization in Wireless Sensor Networks (WSN's active at 2.4 GHz. Advantages and disadvantages of the technology are discussed and act as a guideline for improving localization accuracy. Tests concerning TOA are performed by means of the location engine of Nanotron. Adapting this engine leads to improved localization results. It is shown that TOA measurements are susceptible to reflections and dynamic environments.

  2. Access Point Backhaul Resource Aggregation as a Many-to-One Matching Game in Wireless Local Area Networks

    Directory of Open Access Journals (Sweden)

    Kawther Hassine

    2017-01-01

    Full Text Available This paper studies backhaul bandwidth aggregation in the context of a wireless local area network composed of two different types of access points: those with spare backhaul capacity (which we term providers and those in shortage of it (beneficiaries; the aim is to transfer excess capacity from providers to beneficiaries. We model the system as a matching game with many-to-one setting wherein several providers can be matched to one beneficiary and adopt the so-called deferred acceptance algorithm to reach an optimal and stable solution. We consider two flavors, when the beneficiaries are limited in their resource demands and when they are not, and two scenarios, when resources are abundant and when they are scarce. Our results show that the many-to-one setting outperforms the one-to-one case in terms of overall throughput gain, resource usage, and individual beneficiaries satisfaction by up to 50%, whether resources are scarce or abundant. As of the limited versus nonlimited case, the former ensures more fair sharing of spectral resources and higher satisfaction percentage between beneficiaries.

  3. Localization-Free Detection of Replica Node Attacks in Wireless Sensor Networks Using Similarity Estimation with Group Deployment Knowledge

    Directory of Open Access Journals (Sweden)

    Chao Ding

    2017-01-01

    Full Text Available Due to the unattended nature and poor security guarantee of the wireless sensor networks (WSNs, adversaries can easily make replicas of compromised nodes, and place them throughout the network to launch various types of attacks. Such an attack is dangerous because it enables the adversaries to control large numbers of nodes and extend the damage of attacks to most of the network with quite limited cost. To stop the node replica attack, we propose a location similarity-based detection scheme using deployment knowledge. Compared with prior solutions, our scheme provides extra functionalities that prevent replicas from generating false location claims without deploying resource-consuming localization techniques on the resource-constraint sensor nodes. We evaluate the security performance of our proposal under different attack strategies through heuristic analysis, and show that our scheme achieves secure and robust replica detection by increasing the cost of node replication. Additionally, we evaluate the impact of network environment on the proposed scheme through theoretic analysis and simulation experiments, and indicate that our scheme achieves effectiveness and efficiency with substantially lower communication, computational, and storage overhead than prior works under different situations and attack strategies.

  4. Wormholes no more? Localized Wormhole Detection and Prevention in Wireless Networks

    DEFF Research Database (Denmark)

    Tassos, Dimitriou; Giannetsos, Athanasios

    2010-01-01

    localized and works by looking for simple evidence that no attack is taking place, using only connectivity information as implied by the underlying communication graph, and total absence of coordination. Unlike many existing techniques, it does not use any specialized hardware, making it extremely useful...

  5. Ultrasound Indoor Positioning System Based on a Low-Power Wireless Sensor Network Providing Sub-Centimeter Accuracy

    Science.gov (United States)

    Medina, Carlos; Segura, José Carlos; De la Torre, Ángel

    2013-01-01

    This paper describes the TELIAMADE system, a new indoor positioning system based on time-of-flight (TOF) of ultrasonic signal to estimate the distance between a receiver node and a transmitter node. TELIAMADE system consists of a set of wireless nodes equipped with a radio module for communication and a module for the transmission and reception of ultrasound. The access to the ultrasonic channel is managed by applying a synchronization algorithm based on a time-division multiplexing (TDMA) scheme. The ultrasonic signal is transmitted using a carrier frequency of 40 kHz and the TOF measurement is estimated by applying a quadrature detector to the signal obtained at the A/D converter output. Low sampling frequencies of 17.78 kHz or even 12.31 kHz are possible using quadrature sampling in order to optimize memory requirements and to reduce the computational cost in signal processing. The distance is calculated from the TOF taking into account the speed of sound. An excellent accuracy in the estimation of the TOF is achieved using parabolic interpolation to detect of maximum of the signal envelope at the matched filter output. The signal phase information is also used for enhancing the TOF measurement accuracy. Experimental results show a root mean square error (rmse) less than 2 mm and a standard deviation less than 0.3 mm for pseudorange measurements in the range of distances between 2 and 6 m. The system location accuracy is also evaluated by applying multilateration. A sub-centimeter location accuracy is achieved with an average rmse of 9.6 mm. PMID:23486218

  6. Ultrasound Indoor Positioning System Based on a Low-Power Wireless Sensor Network Providing Sub-Centimeter Accuracy

    Directory of Open Access Journals (Sweden)

    Ángel De la Torre

    2013-03-01

    Full Text Available This paper describes the TELIAMADE system, a new indoor positioning system based on time-of-flight (TOF of ultrasonic signal to estimate the distance between a receiver node and a transmitter node. TELIAMADE system consists of a set of wireless nodes equipped with a radio module for communication and a module for the transmission and reception of ultrasound. The access to the ultrasonic channel is managed by applying a synchronization algorithm based on a time-division multiplexing (TDMA scheme. The ultrasonic signal is transmitted using a carrier frequency of 40 kHz and the TOF measurement is estimated by applying a quadrature detector to the signal obtained at the A/D converter output. Low sampling frequencies of 17.78 kHz or even 12.31 kHz are possible using quadrature sampling in order to optimize memory requirements and to reduce the computational cost in signal processing. The distance is calculated from the TOF taking into account the speed of sound. An excellent accuracy in the estimation of the TOF is achieved using parabolic interpolation to detect of maximum of the signal envelope at the matched filter output. The signal phase information is also used for enhancing the TOF measurement accuracy. Experimental results show a root mean square error (rmse less than 2 mm and a standard deviation less than 0.3 mm for pseudorange measurements in the range of distances between 2 and 6 m. The system location accuracy is also evaluated by applying multilateration. A sub-centimeter location accuracy is achieved with an average rmse of 9.6 mm.

  7. Detecting measurement-induced relative-position localization

    International Nuclear Information System (INIS)

    Knott, P A; Sindt, J; Dunningham, J A

    2013-01-01

    The theory of decoherence explains how classicality emerges from an underlying quantum reality. An additional interpretation to this has been proposed in which scattering events induce the localization of relative observables (Rau et al 2003 Science 301 1081). An interesting consequence of this process is that it involves the build-up of certain robust entanglements between the observables being localized. To date the weakness of this interpretation has been the lack of a clear experimental signature that allows it to be tested. Here we provide a simple experimentally accessible scheme that enables just that. We also discuss a Bayesian technique that could, in principle, allow experiments to confirm the localization to any desired degree of accuracy and we present precision requirements that are achievable with current experiments. Finally, we extend the scheme from its initial one dimensional proof of principle to the more real world scenario of three dimensional localization. (paper)

  8. Secure Neighbor Discovery in Wireless Sensor Networks Using Range-Free Localization Techniques

    OpenAIRE

    Garcia-Otero, Mariano; Poblacion-Hernandez, Adrian

    2012-01-01

    Si una red inalámbrica de sensores se implementa en un entorno hostil, las limitaciones intrínsecas a los nodos conllevan muchos problemas de seguridad. En este artículo se aborda un ataque particular a los protocolos de localización y descubrimiento de vecinos, llevada a cabo por dos nodos que actúan en connivencia y establecen un "agujero de gusano" para tratar de engañar a un nodo aislado, haciéndole creer que se encuentra en la vecindad de un conjunto de nodos locales. Para contrarrestar ...

  9. Efficient DV-HOP Localization for Wireless Cyber-Physical Social Sensing System: A Correntropy-Based Neural Network Learning Scheme

    Directory of Open Access Journals (Sweden)

    Yang Xu

    2017-01-01

    Full Text Available Integrating wireless sensor network (WSN into the emerging computing paradigm, e.g., cyber-physical social sensing (CPSS, has witnessed a growing interest, and WSN can serve as a social network while receiving more attention from the social computing research field. Then, the localization of sensor nodes has become an essential requirement for many applications over WSN. Meanwhile, the localization information of unknown nodes has strongly affected the performance of WSN. The received signal strength indication (RSSI as a typical range-based algorithm for positioning sensor nodes in WSN could achieve accurate location with hardware saving, but is sensitive to environmental noises. Moreover, the original distance vector hop (DV-HOP as an important range-free localization algorithm is simple, inexpensive and not related to the environment factors, but performs poorly when lacking anchor nodes. Motivated by these, various improved DV-HOP schemes with RSSI have been introduced, and we present a new neural network (NN-based node localization scheme, named RHOP-ELM-RCC, through the use of DV-HOP, RSSI and a regularized correntropy criterion (RCC-based extreme learning machine (ELM algorithm (ELM-RCC. Firstly, the proposed scheme employs both RSSI and DV-HOP to evaluate the distances between nodes to enhance the accuracy of distance estimation at a reasonable cost. Then, with the help of ELM featured with a fast learning speed with a good generalization performance and minimal human intervention, a single hidden layer feedforward network (SLFN on the basis of ELM-RCC is used to implement the optimization task for obtaining the location of unknown nodes. Since the RSSI may be influenced by the environmental noises and may bring estimation error, the RCC instead of the mean square error (MSE estimation, which is sensitive to noises, is exploited in ELM. Hence, it may make the estimation more robust against outliers. Additionally, the least square

  10. Efficient DV-HOP Localization for Wireless Cyber-Physical Social Sensing System: A Correntropy-Based Neural Network Learning Scheme.

    Science.gov (United States)

    Xu, Yang; Luo, Xiong; Wang, Weiping; Zhao, Wenbing

    2017-01-12

    Integrating wireless sensor network (WSN) into the emerging computing paradigm, e.g., cyber-physical social sensing (CPSS), has witnessed a growing interest, and WSN can serve as a social network while receiving more attention from the social computing research field. Then, the localization of sensor nodes has become an essential requirement for many applications over WSN. Meanwhile, the localization information of unknown nodes has strongly affected the performance of WSN. The received signal strength indication (RSSI) as a typical range-based algorithm for positioning sensor nodes in WSN could achieve accurate location with hardware saving, but is sensitive to environmental noises. Moreover, the original distance vector hop (DV-HOP) as an important range-free localization algorithm is simple, inexpensive and not related to the environment factors, but performs poorly when lacking anchor nodes. Motivated by these, various improved DV-HOP schemes with RSSI have been introduced, and we present a new neural network (NN)-based node localization scheme, named RHOP-ELM-RCC, through the use of DV-HOP, RSSI and a regularized correntropy criterion (RCC)-based extreme learning machine (ELM) algorithm (ELM-RCC). Firstly, the proposed scheme employs both RSSI and DV-HOP to evaluate the distances between nodes to enhance the accuracy of distance estimation at a reasonable cost. Then, with the help of ELM featured with a fast learning speed with a good generalization performance and minimal human intervention, a single hidden layer feedforward network (SLFN) on the basis of ELM-RCC is used to implement the optimization task for obtaining the location of unknown nodes. Since the RSSI may be influenced by the environmental noises and may bring estimation error, the RCC instead of the mean square error (MSE) estimation, which is sensitive to noises, is exploited in ELM. Hence, it may make the estimation more robust against outliers. Additionally, the least square estimation (LSE

  11. Wireless network security theories and applications

    CERN Document Server

    Chen, Lei; Zhang, Zihong

    2013-01-01

    Wireless Network Security Theories and Applications discusses the relevant security technologies, vulnerabilities, and potential threats, and introduces the corresponding security standards and protocols, as well as provides solutions to security concerns. Authors of each chapter in this book, mostly top researchers in relevant research fields in the U.S. and China, presented their research findings and results about the security of the following types of wireless networks: Wireless Cellular Networks, Wireless Local Area Networks (WLANs), Wireless Metropolitan Area Networks (WMANs), Bluetooth

  12. ns-2 extension to simulate localization system in wireless sensor networks

    CSIR Research Space (South Africa)

    Abu-Mahfouz, Adnan M

    2011-09-01

    Full Text Available of references and termination criterion. As shown in Fig. 2, the Position class uses the MMSE and LocDisApp classes and the ReferenceNode structure, which consists of two members, location variable and double variables to store the measured distance..., such as the routing protocol, MAC type and so on. In addition to these configurations it is also required to specify the attribute of the nodes (either BEACON or UNKNOWN), which can be done with the help of the command ?node-config?. For example, the following...

  13. Data converters for wireless standards

    CERN Document Server

    Shi, Chunlei

    2002-01-01

    Wireless communication is witnessing tremendous growth with proliferation of different standards covering wide, local and personal area networks (WAN, LAN and PAN). The trends call for designs that allow 1) smooth migration to future generations of wireless standards with higher data rates for multimedia applications, 2) convergence of wireless services allowing access to different standards from the same wireless device, 3) inter-continental roaming. This requires designs that work across multiple wireless standards, can easily be reused, achieve maximum hardware share at a minimum power consumption levels particularly for mobile battery-operated devices.

  14. Adaptive quantization of local field potentials for wireless implants in freely moving animals: an open-source neural recording device

    Science.gov (United States)

    Martinez, Dominique; Clément, Maxime; Messaoudi, Belkacem; Gervasoni, Damien; Litaudon, Philippe; Buonviso, Nathalie

    2018-04-01

    Objective. Modern neuroscience research requires electrophysiological recording of local field potentials (LFPs) in moving animals. Wireless transmission has the advantage of removing the wires between the animal and the recording equipment but is hampered by the large number of data to be sent at a relatively high rate. Approach. To reduce transmission bandwidth, we propose an encoder/decoder scheme based on adaptive non-uniform quantization. Our algorithm uses the current transmitted codeword to adapt the quantization intervals to changing statistics in LFP signals. It is thus backward adaptive and does not require the sending of side information. The computational complexity is low and similar at the encoder and decoder sides. These features allow for real-time signal recovery and facilitate hardware implementation with low-cost commercial microcontrollers. Main results. As proof-of-concept, we developed an open-source neural recording device called NeRD. The NeRD prototype digitally transmits eight channels encoded at 10 kHz with 2 bits per sample. It occupies a volume of 2  ×  2  ×  2 cm3 and weighs 8 g with a small battery allowing for 2 h 40 min of autonomy. The power dissipation is 59.4 mW for a communication range of 8 m and transmission losses below 0.1%. The small weight and low power consumption offer the possibility of mounting the entire device on the head of a rodent without resorting to a separate head-stage and battery backpack. The NeRD prototype is validated in recording LFPs in freely moving rats at 2 bits per sample while maintaining an acceptable signal-to-noise ratio (>30 dB) over a range of noisy channels. Significance. Adaptive quantization in neural implants allows for lower transmission bandwidths while retaining high signal fidelity and preserving fundamental frequencies in LFPs.

  15. Determining the localization of premolar zenith positions according ...

    African Journals Online (AJOL)

    2014-09-03

    Sep 3, 2014 ... Department of Prosthodontics, Ondokuz Mayis University, Faculty of Dentistry, Atakum, Samsun,. 1Department of Prosthodontics ... Alginate impressions of the study group were made using irreversible hydrocolloid ... cast model using digital Vernier caliper, and the readings were noted as mm. Positive ...

  16. An Improved Compressive Sensing and Received Signal Strength-Based Target Localization Algorithm with Unknown Target Population for Wireless Local Area Networks

    Directory of Open Access Journals (Sweden)

    Jun Yan

    2017-05-01

    Full Text Available In this paper a two-phase compressive sensing (CS and received signal strength (RSS-based target localization approach is proposed to improve position accuracy by dealing with the unknown target population and the effect of grid dimensions on position error. In the coarse localization phase, by formulating target localization as a sparse signal recovery problem, grids with recovery vector components greater than a threshold are chosen as the candidate target grids. In the fine localization phase, by partitioning each candidate grid, the target position in a grid is iteratively refined by using the minimum residual error rule and the least-squares technique. When all the candidate target grids are iteratively partitioned and the measurement matrix is updated, the recovery vector is re-estimated. Threshold-based detection is employed again to determine the target grids and hence the target population. As a consequence, both the target population and the position estimation accuracy can be significantly improved. Simulation results demonstrate that the proposed approach achieves the best accuracy among all the algorithms compared.

  17. EMULACIÓN DE ESCENARIOS VIRTUALES, EN UNA SDWLAN (SOFTWARE DEFINED WIRELESS LOCAL AREA NETWORK, DE UN CAMPUS UNIVERSITARIO

    Directory of Open Access Journals (Sweden)

    Gerlyn Duarte

    2015-07-01

    Full Text Available Las redes definidas por software (SDN = Software Defined Network es una arquitectura de red emergente que se destaca como una tecnología capaz de ofrecer un control más flexible y dinámico a la hora de gestionar el diseño y funciones de la red, donde se separan los planos de control y enrutamiento. Esto permite la centralización de los controles de la red basada en software. Se puede decir que es posible tener flexibilidad y rapidez al momento de configurar, implementar y administrar diferentes protocolos personalizados para los requerimientos de distintas redes. Actualmente, en una red convencional, cada conmutador y/o enrutador tienen software propietario que le dice qué hacer. SDN se centra principalmente en la parte cableada de la red de datos. Sin embargo, todas las ventajas de las SDN sólo se obtienen si se logra abarcar la totalidad de la infraestructura, desde el centro de datos al extremo de la red, permitiendo extender todos los beneficios de SDN hasta la red inalámbrica, para conseguir a su vez una red inalámbrica de área local definida por software (SDWLAN = Software Define Wireless Local Area Network. Es por ello que en el presente trabajo, se emuló parte de una SDWLAN de un campus universitario para observar la factibilidad de implementar SDN en la misma. Para la emulación se utilizó una variante del emulador Mininet que permite trabajar con redes inalámbricas. De igual forma, se efectuaron mediciones del ancho de banda de las SDWLAN emuladas, así como la interconectividad entre ellas. Se evidenció la facilidad y el rendimiento de trabajar con las herramientas de emulación de SDWLAN empleadas, permitiendo de igual forma la estructuración de distintas topologías de SDWLAN. Se comprobó que el emulador, el cual está aún en la fase beta, permite interactuar y ejecutar cualquier proceso como si se ejecutara directamente en un equipo con GNU/Linux de forma eficaz.

  18. Developmental regulation of a local positive autocontrol of supraoptic neurons.

    Science.gov (United States)

    Chevaleyre, V; Dayanithi, G; Moos, F C; Desarmenien, M G

    2000-08-01

    Mature oxytocin (OT) and vasopressin (AVP) magnocellular neurons of the hypothalamic supraoptic nuclei (SON) autocontrol their electrical activity via somatodendritic release of their respective peptides. Because OT and AVP are synthesized early in development and could play an important role in the maturation of these neurons, we checked whether the peptides are released within the SON and act on their secreting neurons during 3 weeks of postnatal development. We used patch-clamp recordings from SON neurons in rat hypothalamic horizontal slices to show that the spontaneous electrical activity of immature SON neurons is blocked by OT or AVP receptor antagonists, demonstrating a basal somatodendritic release of the peptides. Application of OT or AVP depolarizes SON neurons and stimulates activity typical of the corresponding mature neurons. This effect is directly on SON neurons because it is recorded in dissociated neurons. Radioimmunoassays from isolated SON were used to show that each peptide facilitates its own release at a somatodendritic level, exhibiting a self-sustaining positive feedback loop. This autocontrol is not uniform during development because the proportion of neurons depolarized by the peptides, the amplitude of the depolarization, and the propensity of the peptides to facilitate their own release are maximal during the second postnatal week and decrease thereafter. These data are consistent with a role of autocontrol in the maturation of SON neurons because it is maximal during the delimited period of postnatal development that corresponds to the period of major synapse formation.

  19. Wireless Access

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Wireless Access. Wireless connect to the Base station. Easy and Convenient access. Costlier as compared to the wired technology. Reliability challenges. We see it as a complementary technology to the DSL.

  20. Position of the Translator as an Agent in Website Localization: The Case of Turkey

    Science.gov (United States)

    Alkan, Sinem Canim

    2017-01-01

    The rapid growth of e-commerce has contributed to the development of website localization activity as a major professional industry. Despite the high volume of website localization practices, there is little research on translators participating in website localization projects. The purpose of this qualitative study was to explore the position of…

  1. Maximally-localized position, Euclidean path-integral, and thermodynamics in GUP quantum mechanics

    Science.gov (United States)

    Bernardo, Reginald Christian S.; Esguerra, Jose Perico H.

    2018-04-01

    In dealing with quantum mechanics at very high energies, it is essential to adapt to a quasiposition representation using the maximally-localized states because of the generalized uncertainty principle. In this paper, we look at maximally-localized states as eigenstates of the operator ξ = X + iβP that we refer to as the maximally-localized position. We calculate the overlap between maximally-localized states and show that the identity operator can be expressed in terms of the maximally-localized states. Furthermore, we show that the maximally-localized position is diagonal in momentum-space and that the maximally-localized position and its adjoint satisfy commutation and anti-commutation relations reminiscent of the harmonic oscillator commutation and anti-commutation relations. As application, we use the maximally-localized position in developing the Euclidean path-integral and introduce the compact form of the propagator for maximal localization. The free particle momentum-space propagator and the propagator for maximal localization are analytically evaluated up to quadratic-order in β. Finally, we obtain a path-integral expression for the partition function of a thermodynamic system using the maximally-localized states. The partition function of a gas of noninteracting particles is evaluated. At temperatures exceeding the Planck energy, we obtain the gas' maximum internal energy N / 2 β and recover the zero heat capacity of an ideal gas.

  2. Visual-based simultaneous localization and mapping and global positioning system correction for geo-localization of a mobile robot

    International Nuclear Information System (INIS)

    Berrabah, Sid Ahmed; Baudoin, Yvan; Sahli, Hichem

    2011-01-01

    This paper introduces an approach combining visual-based simultaneous localization and mapping (V-SLAM) and global positioning system (GPS) correction for accurate multi-sensor localization of an outdoor mobile robot in geo-referenced maps. The proposed framework combines two extended Kalman filters (EKF); the first one, referred to as the integration filter, is dedicated to the improvement of the GPS localization based on data from an inertial navigation system and wheels' encoders. The second EKF implements the V-SLAM process. The linear and angular velocities in the dynamic model of the V-SLAM EKF filter are given by the GPS/INS/Encoders integration filter. On the other hand, the output of the V-SLAM EKF filter is used to update the dynamics estimation in the integration filter and therefore the geo-referenced localization. This solution increases the accuracy and the robustness of the positioning during GPS outage and allows SLAM in less featured environments

  3. On Designing Thermal-Aware Localized QoS Routing Protocol for in-vivo Sensor Nodes in Wireless Body Area Networks

    Directory of Open Access Journals (Sweden)

    Muhammad Mostafa Monowar

    2015-06-01

    Full Text Available In this paper, we address the thermal rise and Quality-of-Service (QoS provisioning issue for an intra-body Wireless Body Area Network (WBAN having in-vivo sensor nodes. We propose a thermal-aware QoS routing protocol, called TLQoS, that facilitates the system in achieving desired QoS in terms of delay and reliability for diverse traffic types, as well as avoids the formation of highly heated nodes known as hotspot(s, and keeps the temperature rise along the network to an acceptable level. TLQoS exploits modular architecture wherein different modules perform integrated operations in providing multiple QoS service with lower temperature rise. To address the challenges of highly dynamic wireless environment inside the human body. TLQoS implements potential-based localized routing that requires only local neighborhood information. TLQoS avoids routing loop formation as well as reduces the number of hop traversal exploiting hybrid potential, and tuning a configurable parameter. We perform extensive simulations of TLQoS, and the results show that TLQoS has significant performance improvements over state-of-the-art approaches.

  4. On Designing Thermal-Aware Localized QoS Routing Protocol for in-vivo Sensor Nodes in Wireless Body Area Networks.

    Science.gov (United States)

    Monowar, Muhammad Mostafa; Bajaber, Fuad

    2015-06-15

    In this paper, we address the thermal rise and Quality-of-Service (QoS) provisioning issue for an intra-body Wireless Body Area Network (WBAN) having in-vivo sensor nodes. We propose a thermal-aware QoS routing protocol, called TLQoS, that facilitates the system in achieving desired QoS in terms of delay and reliability for diverse traffic types, as well as avoids the formation of highly heated nodes known as hotspot(s), and keeps the temperature rise along the network to an acceptable level. TLQoS exploits modular architecture wherein different modules perform integrated operations in providing multiple QoS service with lower temperature rise. To address the challenges of highly dynamic wireless environment inside the human body. TLQoS implements potential-based localized routing that requires only local neighborhood information. TLQoS avoids routing loop formation as well as reduces the number of hop traversal exploiting hybrid potential, and tuning a configurable parameter. We perform extensive simulations of TLQoS, and the results show that TLQoS has significant performance improvements over state-of-the-art approaches.

  5. A Forensic Readiness Model for Wireless Networks

    OpenAIRE

    Ngobeni, Sipho; Venter, Hein; Burke, Ivan

    2010-01-01

    International audience; Over the past decade, wireless mobile communications technology based on IEEE 802.11 wireless local area networks (WLANs) has been adopted worldwide on a massive scale. However, as the number of wireless users has soared, so has the possibility of cyber crime, where criminals deliberately and actively break into WLANs with the intent to cause harm or access sensitive information. WLAN digital forensics is seen not only as a response to cyber crime in wireless environme...

  6. Localization of the relative position of two atoms induced by spontaneous emission

    International Nuclear Information System (INIS)

    Zheng, L.; Li, C.; Li, Y.; Sun, C.P.

    2005-01-01

    We reexamine the back-action of emitted photons on the wave packet evolution about the relative position of two cold atoms. We show that photon recoil resulting from the spontaneous emission can induce the localization of the relative position of the two atoms through the entanglement between the spatial motion of individual atoms and their emitted photons. The obtained result provides a more realistic model for the analysis of the environment-induced localization of a macroscopic object

  7. Capacity Limit, Link Scheduling and Power Control in Wireless Networks

    Science.gov (United States)

    Zhou, Shan

    2013-01-01

    The rapid advancement of wireless technology has instigated the broad deployment of wireless networks. Different types of networks have been developed, including wireless sensor networks, mobile ad hoc networks, wireless local area networks, and cellular networks. These networks have different structures and applications, and require different…

  8. Method for collecting thermocouple data via secured shell over a wireless local area network in real time.

    Science.gov (United States)

    Arnold, F; DeMallie, I; Florence, L; Kashinski, D O

    2015-03-01

    This manuscript addresses the design, hardware details, construction, and programming of an apparatus allowing an experimenter to monitor and record high-temperature thermocouple measurements of dynamic systems in real time. The apparatus uses wireless network technology to bridge the gap between a dynamic (moving) sample frame and the static laboratory frame. Our design is a custom solution applied to samples that rotate through large angular displacements where hard-wired and typical slip-ring solutions are not practical because of noise considerations. The apparatus consists of a Raspberry PI mini-Linux computer, an Arduino micro-controller, an Ocean Controls thermocouple multiplexer shield, and k-type thermocouples.

  9. Method for collecting thermocouple data via secured shell over a wireless local area network in real time

    Science.gov (United States)

    Arnold, F.; DeMallie, I.; Florence, L.; Kashinski, D. O.

    2015-03-01

    This manuscript addresses the design, hardware details, construction, and programming of an apparatus allowing an experimenter to monitor and record high-temperature thermocouple measurements of dynamic systems in real time. The apparatus uses wireless network technology to bridge the gap between a dynamic (moving) sample frame and the static laboratory frame. Our design is a custom solution applied to samples that rotate through large angular displacements where hard-wired and typical slip-ring solutions are not practical because of noise considerations. The apparatus consists of a Raspberry PI mini-Linux computer, an Arduino micro-controller, an Ocean Controls thermocouple multiplexer shield, and k-type thermocouples.

  10. Positive thinking: an innovative strategy of Local Development in the “Inner Areas"

    OpenAIRE

    Veronica Lo Presti

    2016-01-01

    This paper is a methodological reflection on the use of the "positive thinking approaches" for the promotion of capacity building of the projects in the local and inner areas. Recently, international policies have focused on the need to identify local development strategies to promote the capacity building in the local administrations, for the development of human and social capital.In the inner areas, it is necessary to experiment innovative approaches that are "place based" and “tailor made...

  11. Neural network-based multiuser detection for SDMA-OFDM system over IEEE 802.11n indoor wireless local area network channel models

    Science.gov (United States)

    Praveen Bagadi, Kala; Das, Susmita

    2013-10-01

    Space division multiple access - orthogonal frequency division multiplexing-based wireless communication has the potential to offer high-spectral efficiency, system performance and capacity. This article proposes an efficient blind multiuser detection (MUD) scheme using artificial neural network models such as the radial basis function. The proposed MUD technique is consistently outperforming the existing minimum mean square error and minimum bit error rate (MBER) MUDs with the performance close to the optimal maximum likelihood (ML) detector. Besides that, the computational complexity of the proposed one is comparatively lower than both the MBER and ML detectors. Further, it can also outperform MBER MUD in the overload scenario, where the number of users is more than that of the number of receiving antennas simulation-based study showing BER performance and complexity are carried out to prove the efficiency of the proposed techniques. This analysis is carried through the IEEE 802.11n standard channel models, which are designed for indoor wireless local area network applications of bandwidth up to 100 MHz at frequencies 2 and 5 GHz.

  12. Wireless virtualization

    CERN Document Server

    Wen, Heming; Le-Ngoc, Tho

    2013-01-01

    This SpringerBriefs is an overview of the emerging field of wireless access and mobile network virtualization. It provides a clear and relevant picture of the current virtualization trends in wireless technologies by summarizing and comparing different architectures, techniques and technologies applicable to a future virtualized wireless network infrastructure. The readers are exposed to a short walkthrough of the future Internet initiative and network virtualization technologies in order to understand the potential role of wireless virtualization in the broader context of next-generation ubiq

  13. Wireless Internet

    NARCIS (Netherlands)

    el Zarki, M.; Heijenk, Geert; Lee, Kenneth S.; Bidgoli, H.

    This chapter addresses the topic of wireless Internet, the extension of the wireline Internet architecture to the wireless domain. As such the chapter introduces the reader to the dominant characteristics of the Internet, from its structure to the protocols that control the forwarding of data and

  14. Networking wireless sensors

    National Research Council Canada - National Science Library

    Krishnamachari, Bhaskar

    2005-01-01

    ... by networking techniques across multiple layers. The topics covered include network deployment, localization, time synchronization, wireless radio characteristics, medium-access, topology control, routing, data-centric techniques, and transport protocols. Ideal for researchers and designers seeking to create new algorithms and protocols and enginee...

  15. Positive thinking: an innovative strategy of Local Development in the “Inner Areas"

    Directory of Open Access Journals (Sweden)

    Veronica Lo Presti

    2016-11-01

    Full Text Available This paper is a methodological reflection on the use of the "positive thinking approaches" for the promotion of capacity building of the projects in the local and inner areas. Recently, international policies have focused on the need to identify local development strategies to promote the capacity building in the local administrations, for the development of human and social capital.In the inner areas, it is necessary to experiment innovative approaches that are "place based" and “tailor made” for the projects to achieve the objectives of the National Strategy of the Inner Areas”The paper presents the “positive thinking approaches” as an innovative strategy of local development in the inner areas. The positive thinking approaches start from the analysis of "what has worked well", with a focus on the co-construction of the "successes", because “you learn more from successes than  failures”.In particular, the article presents three positive thinking approaches (EI, evaluation of innovation; DE - developmental evaluation, and MSC - Most Significant Change. The aim is to explore what these approaches share in the Inner Areas. The advantage of positive thinking approaches is their ability to capitalize on unexpected positive effects. EI, DE and MSC recognise that the good practice that has been detected needs to be adapted to other situations by thoughtful agents. In both cases, a detected success will need responsible actors to produce further success.

  16. GNSS-based train positioning experiments with local and wide area augmentation

    Energy Technology Data Exchange (ETDEWEB)

    Gu, X.; Schmidt, M.; Winter, J. [DaimlerChrysler Rail Systems (Signals) GmbH, Ulm (Germany)

    1999-07-01

    Within the frame of the MAGNET Project ('Multimodal Approach for GNSS 1 in European Transport') of the Telematics Applications programme of the 4{sup th} Research Framework of the European Community (1994-1998), a GNSS-based Train Positioning Platform (TPP) has been developed and tested with the wide area augmentation system pre-EGNOS and a local differential GNSS system using a reference station. This paper presents the principle and the system architecture of the developed GNSS-based train positioning system and highlights the system performance achieved in field tests. The TPP consists of a GNSS core module with an EGNOS (European Geostationary Navigation Overlay Service) decoding function, a GSM (Global System for Mobile Communication) data link for local GPS and GLONASS differential corrections, a digital route map and an interface to odometer. The first step to calculate the train position is to select either wide area or local area differential corrections depending on which are available. The position and velocity are then calculated and matched to the track by using the digital route map. Finally, the GNSS position and velocity data is integrated with odometer data in a sensor data fusion model. The integrated solution avoids the masking problem of GNSS signals and reduces odometer errors like drift and braking slip, so that a continuous positioning availability can be reached and the positioning accuracy can be improved to meter level. The achieved performance is being exploited for industrial applications. (orig.)

  17. Comparison of different local and imported histamine concentrations used as a skin prick test positive control.

    Science.gov (United States)

    Visitsunthorn, Nualanong; Visitsunthorn, Kittipos; Aulla, Sunisa; Bunnag, Chaweewan; Jirapongsananuruk, Orathai

    2016-12-01

    The skin prick test (SPT) is a valid and approved tool that is used to diagnose atopic diseases. The SPT is accurate, safe, simple and inexpensive. However, the histamine concentration used as a positive control in the SPT varies among centers. To compare SPT results using different concentrations of locally-prepared and imported histamine solutions. This prospective, randomized, double-blind, self-controlled study was performed in healthy adult volunteers. The SPT was performed using 4 concentrations of histamine solutions (imported, 1 mg/mL; locally-prepared, 1, 5 and 10 mg/mL). Locally-prepared histamine positive controls were prepared from histamine biphosphate monohydrate using sterile technique. Seventy-five adult volunteers (mean age, 36 years) were included in the study. Eight volunteers were male and 9 had a history of atopy. Mean wheal diameter (MWD) for imported histamine was 3.49 mm for a concentration of 1 mg/mL, and that of locally-prepared histamine was 2.94 mm, 5.05 mm and 5.52 mm for concentrations of 1, 5 and 10 mg/mL histamine, respectively. Negative SPT results (MWD histamine and 26 subjects (34.7%) who received the locally-prepared histamine at concentration of 1 mg/mL. All subjects tested with locally-prepared histamine at concentrations of 5 and 10 mg/mL had a MWD > 3 mm. Locally-prepared histamine base at concentrations of 5 and 10 mg/mL yielded better positive results than both imported and locally-prepared histamine at a concentration of 1 mg/mL.

  18. Uncertainty related to position and momentum localization of a quantum state

    OpenAIRE

    Rudnicki, Łukasz

    2010-01-01

    This paper presents the uncertainty related to position and momentum localization of a quantum state in terms of entropic uncertainty relations. We slightly improve the inequality given in [Phys. Rev. A 74, 052101 (2006)] and introduce a new entropic measure with corresponding uncertainty relation.

  19. Local positive feedback and the persistence and recovery of fringe Avicennia marina (Forssk.) Vierh. mangroves

    NARCIS (Netherlands)

    Huisman, T.J.; Langevelde, van F.; Boer, de W.F.

    2009-01-01

    While mangrove restoration efforts are reasonably successful, failure often occurs in high wave energy situations. Due to differences in wave energy, seedling mortality rates vary strongly with position on the intertidal flat between high water spring and high water neap elevations. However, a local

  20. Spatiotemporal Local-Remote Senor Fusion (ST-LRSF) for Cooperative Vehicle Positioning.

    Science.gov (United States)

    Jeong, Han-You; Nguyen, Hoa-Hung; Bhawiyuga, Adhitya

    2018-04-04

    Vehicle positioning plays an important role in the design of protocols, algorithms, and applications in the intelligent transport systems. In this paper, we present a new framework of spatiotemporal local-remote sensor fusion (ST-LRSF) that cooperatively improves the accuracy of absolute vehicle positioning based on two state estimates of a vehicle in the vicinity: a local sensing estimate, measured by the on-board exteroceptive sensors, and a remote sensing estimate, received from neighbor vehicles via vehicle-to-everything communications. Given both estimates of vehicle state, the ST-LRSF scheme identifies the set of vehicles in the vicinity, determines the reference vehicle state, proposes a spatiotemporal dissimilarity metric between two reference vehicle states, and presents a greedy algorithm to compute a minimal weighted matching (MWM) between them. Given the outcome of MWM, the theoretical position uncertainty of the proposed refinement algorithm is proven to be inversely proportional to the square root of matching size. To further reduce the positioning uncertainty, we also develop an extended Kalman filter model with the refined position of ST-LRSF as one of the measurement inputs. The numerical results demonstrate that the proposed ST-LRSF framework can achieve high positioning accuracy for many different scenarios of cooperative vehicle positioning.

  1. Position Estimation and Local Mapping Using Omnidirectional Images and Global Appearance Descriptors

    Directory of Open Access Journals (Sweden)

    Yerai Berenguer

    2015-10-01

    Full Text Available This work presents some methods to create local maps and to estimate the position of a mobile robot, using the global appearance of omnidirectional images. We use a robot that carries an omnidirectional vision system on it. Every omnidirectional image acquired by the robot is described only with one global appearance descriptor, based on the Radon transform. In the work presented in this paper, two different possibilities have been considered. In the first one, we assume the existence of a map previously built composed of omnidirectional images that have been captured from previously-known positions. The purpose in this case consists of estimating the nearest position of the map to the current position of the robot, making use of the visual information acquired by the robot from its current (unknown position. In the second one, we assume that we have a model of the environment composed of omnidirectional images, but with no information about the location of where the images were acquired. The purpose in this case consists of building a local map and estimating the position of the robot within this map. Both methods are tested with different databases (including virtual and real images taking into consideration the changes of the position of different objects in the environment, different lighting conditions and occlusions. The results show the effectiveness and the robustness of both methods.

  2. Energy-efficient digital and wireless IC design for wireless smart sensing

    Science.gov (United States)

    Zhou, Jun; Huang, Xiongchuan; Wang, Chao; Tae-Hyoung Kim, Tony; Lian, Yong

    2017-10-01

    Wireless smart sensing is now widely used in various applications such as health monitoring and structural monitoring. In conventional wireless sensor nodes, significant power is consumed in wirelessly transmitting the raw data. Smart sensing adds local intelligence to the sensor node and reduces the amount of wireless data transmission via on-node digital signal processing. While the total power consumption is reduced compared to conventional wireless sensing, the power consumption of the digital processing becomes as dominant as wireless data transmission. This paper reviews the state-of-the-art energy-efficient digital and wireless IC design techniques for reducing the power consumption of the wireless smart sensor node to prolong battery life and enable self-powered applications.

  3. An Improved Indoor Positioning System Using RGB-D Cameras and Wireless Networks for Use in Complex Environments

    Directory of Open Access Journals (Sweden)

    Jaime Duque Domingo

    2017-10-01

    Full Text Available This work presents an Indoor Positioning System to estimate the location of people navigating in complex indoor environments. The developed technique combines WiFi Positioning Systems and depth maps, delivering promising results in complex inhabited environments, consisting of various connected rooms, where people are freely moving. This is a non-intrusive system in which personal information about subjects is not needed and, although RGB-D cameras are installed in the sensing area, users are only required to carry their smart-phones. In this article, the methods developed to combine the above-mentioned technologies and the experiments performed to test the system are detailed. The obtained results show a significant improvement in terms of accuracy and performance with respect to previous WiFi-based solutions as well as an extension in the range of operation.

  4. An Improved Indoor Positioning System Using RGB-D Cameras and Wireless Networks for Use in Complex Environments.

    Science.gov (United States)

    Duque Domingo, Jaime; Cerrada, Carlos; Valero, Enrique; Cerrada, Jose A

    2017-10-20

    This work presents an Indoor Positioning System to estimate the location of people navigating in complex indoor environments. The developed technique combines WiFi Positioning Systems and depth maps , delivering promising results in complex inhabited environments, consisting of various connected rooms, where people are freely moving. This is a non-intrusive system in which personal information about subjects is not needed and, although RGB-D cameras are installed in the sensing area, users are only required to carry their smart-phones. In this article, the methods developed to combine the above-mentioned technologies and the experiments performed to test the system are detailed. The obtained results show a significant improvement in terms of accuracy and performance with respect to previous WiFi-based solutions as well as an extension in the range of operation.

  5. Raptor localization predicts prognosis and tamoxifen response in estrogen receptor-positive breast cancer.

    Science.gov (United States)

    Bostner, Josefine; Alayev, Anya; Berman, Adi Y; Fornander, Tommy; Nordenskjöld, Bo; Holz, Marina K; Stål, Olle

    2018-02-01

    Deregulated PI3K/mTOR signals can promote the growth of breast cancer and contribute to endocrine treatment resistance. This report aims to investigate raptor and its intracellular localization to further understand its role in ER-positive breast cancer. Raptor protein expression was evaluated by immunohistochemistry in 756 primary breast tumors from postmenopausal patients randomized to tamoxifen or no tamoxifen. In vitro, the MCF7 breast cancer cell line and tamoxifen-resistant MCF7 cells were studied to track the raptor signaling changes upon resistance, and raptor localization in ERα-positive cell lines was compared with that in ERα-negative cell lines. Raptor protein expression in the nucleus was high in ER/PgR-positive and HER2-negative tumors with low grade, features associated with the luminal A subtype. Presence of raptor in the nucleus was connected with ERα signaling, here shown by a coupled increase of ERα phosphorylation at S167 and S305 with accumulation of nuclear raptor. In addition, the expression of ERα-activated gene products correlated with nuclear raptor. Similarly, in vitro we observed raptor in the nucleus of ERα-positive, but not of ER-negative cells. Interestingly, raptor localized to the nucleus could still be seen in tamoxifen-resistant MCF7 cells. The clinical benefit from tamoxifen was inversely associated with an increase of nuclear raptor. High cytoplasmic raptor expression indicated worse prognosis on long-term follow-up. We present a connection between raptor localization to the nucleus and ERα-positive breast cancer, suggesting raptor as a player in stimulating the growth of the luminal A subtype and a possible target along with endocrine treatment.

  6. Examining the relationship between local extinction risk and position in range.

    Science.gov (United States)

    Boakes, Elizabeth H; Isaac, Nicholas J B; Fuller, Richard A; Mace, Georgina M; McGowan, Philip J K

    2018-02-01

    Over half of globally threatened animal species have experienced rapid geographic range loss. Identifying the parts of species' distributions most vulnerable to local extinction would benefit conservation planning. However, previous studies give little consensus on whether ranges decline to the core or edge. We built on previous work by using empirical data to examine the position of recent local extinctions within species' geographic ranges, address range position as a continuum, and explore the influence of environmental factors. We aggregated point-locality data for 125 Galliform species from across the Palearctic and Indo-Malaya into equal-area half-degree grid cells and used a multispecies dynamic Bayesian occupancy model to estimate rates of local extinctions. Our model provides a novel approach to identify loss of populations from within species ranges. We investigated the relationship between extinction rates and distance from range edge by examining whether patterns were consistent across biogeographic realm and different categories of land use. In the Palearctic, local extinctions occurred closer to the range edge than range core in both unconverted and human-dominated landscapes. In Indo-Malaya, no pattern was found for unconverted landscapes, but in human-dominated landscapes extinctions tended to occur closer to the core than the edge. Our results suggest that local and regional factors override general spatial patterns of recent local extinction within species' ranges and highlight the difficulty of predicting the parts of a species' distribution most vulnerable to threat. © 2017 The Authors. Conservation Biology published by Wiley Periodicals, Inc. on behalf of Society for Conservation Biology.

  7. A Modular Localization System as a Positioning Service for Road Transport

    Directory of Open Access Journals (Sweden)

    Peter Brida

    2014-10-01

    Full Text Available In recent times smart devices have attracted a large number of users. Since many of these devices allow position estimation using Global Navigation Satellite Systems (GNSS signals, a large number of location-based applications and services have emerged, especially in transport systems. However GNSS signals are affected by the environment and are not always present, especially in dense urban environment or indoors. In this work firstly a Modular Localization Algorithm is proposed to allow seamless switching between different positioning modules. This helps us develop a positioning system that is able to provide position estimates in both indoor and outdoor environments without any user interaction. Since the proposed system can run as a service on any smart device, it could allow users to navigate not only in outdoor environments, but also indoors, e.g., underground garages, tunnels etc. Secondly we present the proposal of a 2-phase map reduction algorithm which allows one to significantly reduce the complexity of position estimation processes in case that positioning is performed using a fingerprinting framework. The proposed 2-phase map reduction algorithm can also improve the accuracy of the position estimates by filtering out reference points that are far from the mobile device. Both algorithms were implemented into a positioning system and tested in real world conditions in both indoor and outdoor environments.

  8. On-Line Target Position Localization in the Presence of Respiration: A Comparison of two Methods

    International Nuclear Information System (INIS)

    Hugo, Geoffrey D.; Liang Jian; Campbell, Jonathan; Yan Di

    2007-01-01

    Purpose: To compare two 'four-dimensional' methods for image-guided target localization in the presence of respiration. Methods and Materials: Four-dimensional image guidance was performed with two methods. A respiration-correlated computed tomography (RCCT) was acquired on a CT simulator, and an average CT (AVG-CT) image was generated from the RCCT. A respiration-correlated cone-beam CT (RC-CBCT) and a free-breathing cone-beam CT (FB-CBCT) were acquired. The 'RCCT method' consisted of calculating the mean target position on both the RCCT and RC-CBCT, registering the RCCT to the RC-CBCT, and determining the shift in the mean target position from the planned mean position. The 'AVG-CT method' consisted of registering the AVG-CT to the FB-CBCT. The ability of each to measure the shift in the mean target position was compared, both in a respiratory phantom and in 8 patients. Results: In phantom, the RCCT and AVG-CT methods were able to measure the true mean target position to within 0.15 cm and 0.10 cm, respectively. In the patient study, the mean error between the methods was 0.13 cm (left-right), 0.14 cm (anterior-posterior), and 0.10 cm (cranio-caudal). The error was not observed to vary with tumor position or magnitude of tumor motion. Conclusions: Respiration may impact the on-line image guidance process. The RCCT method enables localization of the mean tumor position and measurement of changes in the motion pattern, whereas the AVG-CT method is simple, fast, and easily implemented. We found the methods to be nearly equivalent in detecting shifts in the mean tumor position

  9. Initial experience with ultrasound localization for positioning prostate cancer patients for external beam radiation therapy

    International Nuclear Information System (INIS)

    Serago, C.F.; Chungbin, S.J.; Buskirk, S.J.; Vora, S.A.; McLaughlin, M.P.; Ezzell, G.A.

    2001-01-01

    Purpose: Ultrasound localization of the prostate gland and its immediate surrounding anatomy has been used to guide the positioning of patients for the treatment of prostate cancer. This process was evaluated in terms of: a) quality assurance measures required; b) reproducibility of the ultrasound measurement; c) comparison of patient position between ultrasound and CT localization (prior to treatment); d) predictive indicators of patient anatomy not well suited for ultrasound localization; and e) measurement of prostate organ displacement resultant from ultrasound probe pressure. Materials and Methods: a) Quality assurance tests are performed on a daily and monthly, and semiannual basis. b) The reproducibility of the ultrasound positioning process was evaluated for 15 patients by same day repeat positioning by the same ultrasound operator and between different operators. c) Measurement of the difference between patient position from CT based localization (conventional) and ultrasound based positioning was done for 15 patients. d) Patient's pelvic anatomy was evaluated for 22 patients with pre-treatment CT scans to identify predictors of poor ultrasound image quality. Specifically, the spatial orientation of the prostate relative to the skeletal structure; the depth of the prostate from the anterior surface; the size of the bladder; and the thickness of tissue anterior to the bladder was examined. e) The displacement of the prostate organ as a result of the pressure from the ultrasound probed was measured for 11 patients with duplicate CT scans with and without the probe pressure present. Results: a) Quality assurance tests can detect ultrasound equipment defects that could result in patient alignment errors. b) Self verification tests of ultrasound positioning indicates a precision of less than 3 mm 90 per cent of the time. Intra-operator tests of ultrasound positioning indicates a precision of less than 4 mm 90 per cent of the time. c) Differences in patient

  10. French policy localism: Surfing on ‘Positive Energie Territories’ (Tepos)

    International Nuclear Information System (INIS)

    Nadaï, Alain; Labussière, Olivier; Debourdeau, Ariane; Régnier, Yannick; Cointe, Béatrice; Dobigny, Laure

    2015-01-01

    This paper is interested in sustainable energy initiatives in French rural areas. It follows up the UK debate about ‘localism’. UK policy localism has been cast as neoliberal, framing communities as competent and competitive actors, morally responsible and accountable for their destiny. In France, the emerging policy localism is surfing on an ongoing political structuration of innovative rural territories – ‘Positive Energie Territories’ (TEPOS). The paper presents and discusses the results of a rough census (undertaken in 2012) of significant experiences in this domain. It points to a few experiences and depicts them as risky, trial-and-error transcalar processes that endow locally emergent energy issues with a political dimension. To this extent, they amount to a different way of doing energy policy. The analysis points to an ambiguity in French policy localism. This localism may pave the way for an upscaling of the ongoing TEPOS political structuration, or tend to make TEPOS into demonstration territories within a neoliberal RTD policy approach. In the latter case, it may not necessarily fit territories to pursue their political structuration with a view to the energy transition. - Highlights: • The paper bears witness to the emergence of a French energy policy localism. • It presents a sample of significant local rural experiences in the climate energy domain in rural France. • These experiences are risky, trial-and-error transcalar processes. • They amount to a different way of doing energy policy. • French localism surfs on these innovative territories while remaining ambiguous about the status that it confers on them

  11. Subjective response to foot-fall noise, including localization of the source position

    DEFF Research Database (Denmark)

    Brunskog, Jonas; Hwang, Ha Dong; Jeong, Cheol-Ho

    2011-01-01

    Although an impact noise level is objectively evaluated the same according to current standards, a lightweight floor structure is often subjectively judged more annoying than a heavy homogeneous structure. The hypothesis of the present investigation is that the subjective judgment of impact noise...... is more annoying if the source position can be localized; lightweight structures have a more localized radiation than heavy structures. For the heavy structures the reverberant vibration field is dominant, therefore having a distributed radiation. A listening test is used to assess the subjective...... annoyance, using simulated binaural room impulse responses, with sources being a moving point source or a non-moving surface source, and rooms being a room with a reverberation time of 0.5 s or an anechoic room. The paper concludes that no strong effect of the source localization on the annoyance can...

  12. Subjective Response to Foot-Fall Noise, Including Localization of the Source Position

    DEFF Research Database (Denmark)

    Brunskog, Jonas; Hwang, Ha Dong; Jeong, Cheol-Ho

    2011-01-01

    Although an impact noise level is objectively evaluated the same according to current standards, a lightweight floor structure is often subjectively judged more annoying than a heavy homogeneous structure. The hypothesis of the present investigation is that the subjective judgment of impact noise...... is more annoying if the source position can be localized; lightweight structures have a more localized radiation than heavy structures. For the heavy structures the reverberant vibration field is dominant, therefore having a distributed radiation. A listening test is used to assess the subjective...... annoyance, using simulated binaural room impulse responses, with sources being a moving point source or a nonmoving surface source, and rooms being a room with a reverberation time of 0.5 s or an anechoic room. The paper concludes that no strong effect of the source localization on the annoyance can...

  13. Real Time Localization of Assets in Hospitals Using Quuppa Indoor Positioning Technology

    Science.gov (United States)

    van der Ham, M. F. S.; Zlatanova, S.; Verbree, E.; Voûte, R.

    2016-09-01

    At the most fundamental level, smart buildings deliver useful building services that make occupants productive. Smart asset management in hostipals starts with knowing the whereabouts of medical equipment. This paper investigates the subject of indoor localization of medical equipment in hospitals by defining functional spaces. In order to localize the assets indoors, a localization method is developed that takes into account several factors such as geometrical influences, characteristics of the Quuppa positioning system and obstructions in the indoor environment. For matching the position data to a real world location, several location types are developed by subdividing the floor plan into location clusters. The research has shown that a high-performance level can be achieved for locations that are within the high-resolution range of the receiver. The performance at the smallest subspaces can only be achieved when having a dense distribution of receivers. Test cases that were defined for specific situations in the test-area show successful localization in these subspaces for the majority of the test data.

  14. A RSSI-based parameter tracking strategy for constrained position localization

    Science.gov (United States)

    Du, Jinze; Diouris, Jean-François; Wang, Yide

    2017-12-01

    In this paper, a received signal strength indicator (RSSI)-based parameter tracking strategy for constrained position localization is proposed. To estimate channel model parameters, least mean squares method (LMS) is associated with the trilateration method. In the context of applications where the positions are constrained on a grid, a novel tracking strategy is proposed to determine the real position and obtain the actual parameters in the monitored region. Based on practical data acquired from a real localization system, an experimental channel model is constructed to provide RSSI values and verify the proposed tracking strategy. Quantitative criteria are given to guarantee the efficiency of the proposed tracking strategy by providing a trade-off between the grid resolution and parameter variation. The simulation results show a good behavior of the proposed tracking strategy in the presence of space-time variation of the propagation channel. Compared with the existing RSSI-based algorithms, the proposed tracking strategy exhibits better localization accuracy but consumes more calculation time. In addition, a tracking test is performed to validate the effectiveness of the proposed tracking strategy.

  15. Introduction to wireless sensor networks

    CERN Document Server

    Forster, Anna

    2016-01-01

    Explores real-world wireless sensor network development, deployment, and applications. The book begins with an introduction to wireless sensor networks and their fundamental concepts. Hardware components, operating systems, protocols, and algorithms that make up the anatomy of a sensor node are described in chapter two. Properties of wireless communications, medium access protocols, wireless links, and link estimation protocols are described in chapter three and chapter four. Routing basics and metrics, clustering techniques, time synchronization and localization protocols, as well as sensing techniques are introduced in chapter five to nine. The concluding chapter summarizes the learnt methods and shows how to use them to deploy real-world sensor networks in a structured way.

  16. OPTIMIZATION OF THE POSITION OF THE LOCAL DISTRIBUTION CENTRE OF THE REGIONAL POST LOGISTICS NETWORK

    Directory of Open Access Journals (Sweden)

    Paweł DROŹDZIEL

    2017-09-01

    Full Text Available The phenomenon of the present postal services is the fact that, customers expect the lowest price while maintaining the availability, security and on time delivery of mail items. We can find that, the costs associated with transport of the postal substrate is one of the most important factors affecting the total cost of the postal services. These transport costs depend on various factors such as the investment in vehicles purchase, operational costs of the postal vehicles (costs of maintenance, repairs, fuel costs of the vehicle, etc. labour costs of the drivers and so on. For this reason, it is important to find such an operational - organizational solutions that can reduce the costs associated with the transportation of postal shipments, resulting in reducing the total cost of postal services. One option to do this is to minimize the length of postal transportation routes. This article presents the approach based on the application of graph theory to optimize existing connections of postal logistics network. Published results is oriented to revaluate existing position of local centre and find a location for the new local distribution centre potentially. New location of local distribution centre can to optimize (minimize the total transport costs of the local postal transportation network in area of the Lublin Province.

  17. Distributed medium access control in wireless networks

    CERN Document Server

    Wang, Ping

    2013-01-01

    This brief investigates distributed medium access control (MAC) with QoS provisioning for both single- and multi-hop wireless networks including wireless local area networks (WLANs), wireless ad hoc networks, and wireless mesh networks. For WLANs, an efficient MAC scheme and a call admission control algorithm are presented to provide guaranteed QoS for voice traffic and, at the same time, increase the voice capacity significantly compared with the current WLAN standard. In addition, a novel token-based scheduling scheme is proposed to provide great flexibility and facility to the network servi

  18. Use of Local Intelligence to Reduce Energy Consumption of Wireless Sensor Nodes in Elderly Health Monitoring Systems

    Directory of Open Access Journals (Sweden)

    Thomas J. Lampoltshammer

    2014-03-01

    Full Text Available The percentage of elderly people in European countries is increasing. Such conjuncture affects socio-economic structures and creates demands for resourceful solutions, such as Ambient Assisted Living (AAL, which is a possible methodology to foster health care for elderly people. In this context, sensor-based devices play a leading role in surveying, e.g., health conditions of elderly people, to alert care personnel in case of an incident. However, the adoption of such devices strongly depends on the comfort of wearing the devices. In most cases, the bottleneck is the battery lifetime, which impacts the effectiveness of the system. In this paper we propose an approach to reduce the energy consumption of sensors’ by use of local sensors’ intelligence. By increasing the intelligence of the sensor node, a substantial decrease in the necessary communication payload can be achieved. The results show a significant potential to preserve energy and decrease the actual size of the sensor device units.

  19. Use of Local Intelligence to Reduce Energy Consumption of Wireless Sensor Nodes in Elderly Health Monitoring Systems

    Science.gov (United States)

    Lampoltshammer, Thomas J.; de Freitas, Edison Pignaton; Nowotny, Thomas; Plank, Stefan; da Costa, João Paulo Carvalho Lustosa; Larsson, Tony; Heistracher, Thomas

    2014-01-01

    The percentage of elderly people in European countries is increasing. Such conjuncture affects socio-economic structures and creates demands for resourceful solutions, such as Ambient Assisted Living (AAL), which is a possible methodology to foster health care for elderly people. In this context, sensor-based devices play a leading role in surveying, e.g., health conditions of elderly people, to alert care personnel in case of an incident. However, the adoption of such devices strongly depends on the comfort of wearing the devices. In most cases, the bottleneck is the battery lifetime, which impacts the effectiveness of the system. In this paper we propose an approach to reduce the energy consumption of sensors' by use of local sensors' intelligence. By increasing the intelligence of the sensor node, a substantial decrease in the necessary communication payload can be achieved. The results show a significant potential to preserve energy and decrease the actual size of the sensor device units. PMID:24618777

  20. Impact of positive surgical margin on biochemical recurrence following radical prostatectomy in locally advanced prostate cancer

    Directory of Open Access Journals (Sweden)

    Cavit Ceylan

    2016-10-01

    Full Text Available This study aimed to determine the effect of surgical margin positivity on biochemical recurrence (BCR in patients with locally advanced prostate cancer (PCa who underwent radical retropubic prostatectomy (RRP. The medical records of all patients with locally advanced PCa that underwent RRP were retrospectively reviewed. Patient demographics, digital rectal examination findings, prostate biopsy Gleason score, prostate volume, pre- and post-treatment prostate-specific antigen (PSA levels, definitive pathology Gleason score, surgical margin status, seminal vesicle invasion, perineural invasion, absence or presence of BCR, and the time to BCR were analyzed. The study included 130 patients. The final pathologic examination showed that seven (5.4% patients had T3a disease and 123 (94.6% had T3b disease. In all, 93 (71.5% patients had a positive surgical margin [SM(+], whereas 37 (28.5% patients had a negative surgical margin [SM(−]. Among the seven patients with pT3a disease, four (57.1% had SM(+, whereas 89 (72.4% of the 123 patients with pT3b disease had SM(−. BCR occurred in 11.8% (11 of 93 of patients with SM(+ and in 45.9% (17 of 37 of those with SM(− (p < 0.001. Multivariate logistic regression analysis showed that SM(+ was the only significant predictor of BCR following RRP (relative risk, 0.163; 95% confidence interval (0.062–0.433; p < 0.001. SM(+ in RRP specimens is not always indicative of BCR in patients with locally advanced PCa. RRP should be considered an effective treatment choice for selected patients with locally advanced PCa, despite the associated high SM(+ rate.

  1. Risk factors associated with positive surgical margins following radical prostatectomy for clinically localized prostate cancer

    DEFF Research Database (Denmark)

    Røder, Martin Andreas; Thomsen, Frederik Birkebæk; Christensen, Ib Jarle

    2014-01-01

    OBJECTIVE: The aim of this study was to evaluate the impact of preoperative and surgical parameters, including nerve-sparing technique, on the risk of positive surgical margins (PSM) following radical prostatectomy for clinically localized prostate cancer. MATERIAL AND METHODS: A prospective...... consecutive single-institution Danish cohort of 1148 patients undergoing RP between 1995 and 2011 was investigated. To analyse the impact of covariates on risk of PSM, a multivariate logistic regression model was used, including cT category, biopsy Gleason score, prostate-specific antigen (PSA), percentage...... positive biopsies for cancer (PPB), surgeon and surgical technique. RESULTS: The overall rate of PSM was 31.4%. The risk of PSM depended (p value for Wald χ(2)) on PSA (p

  2. Negative and positive magnetoresistance in bilayer graphene: Effects of weak localization and charge inhomogeneity

    International Nuclear Information System (INIS)

    Chen Yungfu; Bae, Myung-Ho; Chialvo, Cesar; Dirks, Travis; Bezryadin, Alexey; Mason, Nadya

    2011-01-01

    We report measurements of magnetoresistance in bilayer graphene as a function of gate voltage (carrier density) and temperature. We examine multiple contributions to the magnetoresistance, including those of weak localization (WL), universal conductance fluctuations (UCF), and inhomogeneous charge transport. A clear WL signal is evident at all measured gate voltages (in the hole doped regime) and temperature ranges (from 0.25 to 4.3 K), and the phase coherence length extracted from the WL data does not saturate at low temperatures. The WL data is fit to demonstrate that the electron-electron Nyquist scattering is the major source of phase decoherence. A decrease in UCF amplitude with increase in gate voltage and temperature is shown to be consistent with a corresponding decrease in the phase coherence length. In addition, a weak positive magnetoresistance at higher magnetic fields is observed, and attributed to inhomogeneous charge transport. -- Research highlights: → Weak localization theory describes low-field magnetoresistance in bilayer graphene. → Electron-electron Nyquist scattering limits phase coherence in bilayer graphene. → Positive magnetoresistance reveals charge inhomogeneity in bilayer graphene.

  3. Retrospective perceptual distortion of position representation does not lead to delayed localization.

    Science.gov (United States)

    Au, Ricky K C; Ono, Fuminori; Watanabe, Katsumi

    2013-01-01

    Previous studies have reported retrospective influences of visual events that occur after target events. In the attentional attraction effect, a position cue presented after a target stimulus distorts the target's position towards that of the cue. The present study explored the temporal relationship between stimulus presentation and reaction time (RT) in this effect in two experiments. Participants performed a speeded localization task on two vertical lines, the positions of which were to be distorted by an additional attentional cue. No significant difference in RTs was found between the conditions with simultaneous and delayed cues. RTRT was modulated by the perceived (rather than physical) alignment of the lines. In Experiment 2, we manipulated the strength of attentional capture by modulating the color relevance of the cue to the target. Trials with cues producing stronger attentional capture (with cues of a different color from the targets) were found to induce apparently stronger distortion effects. This result favors the notion that the observed repulsion and attraction effects are driven by attentional mechanisms. Overall, the results imply that the attentional shift induced by the cue might occur rapidly and complete before the establishment of conscious location representation of the cue and the target without affecting overall response time.

  4. Comparison of egg positive rates of Enterobius vermicularis among preschool children in three Korean localities.

    Science.gov (United States)

    Hong, Sung-Hee; Lee, Sang-Eun; Jeong, Young-Il; Lee, Won-Ja; Cho, Shin-Hyeong

    2011-12-01

    This survey was performed to investigate and compare egg positive rates (EPRs) of Enterobius vermicularis among preschool children in 3 Korean localities (Chuncheon-si, Inje-gun, and Paju-si) in 2008. A total of 7,048 preschool children were examined. Overall, the total EPR was 4.0%; the EPR was the highest in Chuncheon-si (5.6%), followed by Inje-gun (4.5%) and Paju-si (3.4%). The EPR of boys (4.9%) was higher than that of girls (3.1%). The EPR significantly increased with age, with the highest observed in 5~7-year-olds. These findings demonstrate that E. vermicularis infection is widely prevalent among preschool children in Chuncheon-si, Inje-gun, and Paju-si, Republic of Korea.

  5. Locally optimal control under unknown dynamics with learnt cost function: application to industrial robot positioning

    Science.gov (United States)

    Guérin, Joris; Gibaru, Olivier; Thiery, Stéphane; Nyiri, Eric

    2017-01-01

    Recent methods of Reinforcement Learning have enabled to solve difficult, high dimensional, robotic tasks under unknown dynamics using iterative Linear Quadratic Gaussian control theory. These algorithms are based on building a local time-varying linear model of the dynamics from data gathered through interaction with the environment. In such tasks, the cost function is often expressed directly in terms of the state and control variables so that it can be locally quadratized to run the algorithm. If the cost is expressed in terms of other variables, a model is required to compute the cost function from the variables manipulated. We propose a method to learn the cost function directly from the data, in the same way as for the dynamics. This way, the cost function can be defined in terms of any measurable quantity and thus can be chosen more appropriately for the task to be carried out. With our method, any sensor information can be used to design the cost function. We demonstrate the efficiency of this method through simulating, with the V-REP software, the learning of a Cartesian positioning task on several industrial robots with different characteristics. The robots are controlled in joint space and no model is provided a priori. Our results are compared with another model free technique, consisting in writing the cost function as a state variable.

  6. Tourists and Local Stakeholders Attitudes Towards Offer and Market Position of Tourist Destination Budva

    Directory of Open Access Journals (Sweden)

    Marković Ana Tripković

    2016-12-01

    Full Text Available There are various definitions of tourist destination. All of them define tourist destination as an area with specific tourist facilities and attractions, (primary and secondary elements which tourists choose as their journey goal. Budva individually represents the largest tourist destination due to number of arrivals and overnight stays. During its life cycle Budva has gone through different phases as a tourist destination. This thesis implies that it is not enough to use only common quantitative indicator of visitor number to define proper the position of tourist destination and predict further development. This text is based on a comparative analysis of the attitudes of tourists and local stakeholders in the three field researches, conducted in the period between 2015 and 2016. The thesis comes to the conclusion that the actual growth is based on meeting the needs of existing markets and tourists. On the other side, aspect of desired market position disagrees with scores of tourist offer elements- which should be input for improvement and preparation for the next stage in the destination development.

  7. An Analysis of Electromagnetic Interference (EMI) of Ultra Wideband(UWB) and IEEE 802.11A Wireless Local Area Network (WLAN) Employing Orthogonal Frequency Division Multiplexing (OFDM)

    Science.gov (United States)

    2004-03-01

    be monitored with an electronic monitoring device that records the ambient temperature periodically. The data is collected and logged daily...Fi) Networking Handbook, McGraw-Hill: NY, 2003. [Sal02]. M.P. Salud , Investigation of RF Emissions from Wireless Networks as a Threat to Avionic

  8. Mobile positioning and tracking from conventional to cooperative techniques

    CERN Document Server

    Frattasi, Simone

    2017-01-01

    Current trends in mobile services envisage location-based networking as a major strong stimulator for the development of novel solutions for obtaining positioning information in wireless networks. This book discusses mobile positioning solutions applied on top of current wireless communication networks. Moreover, it introduces advanced and novel topics such as localization in heterogeneous and cooperative scenarios. In this fully updated second edition, the authors summarize recent developments in mobile positioning and tracking. Compared with the previous version, the new edition introduces more advanced topics, providing the bridge between research and industry. It works as an important reference and provides good foundations for new researchers.

  9. Wireless Biological Electronic Sensors.

    Science.gov (United States)

    Cui, Yue

    2017-10-09

    The development of wireless biological electronic sensors could open up significant advances for both fundamental studies and practical applications in a variety of areas, including medical diagnosis, environmental monitoring, and defense applications. One of the major challenges in the development of wireless bioelectronic sensors is the successful integration of biosensing units and wireless signal transducers. In recent years, there are a few types of wireless communication systems that have been integrated with biosensing systems to construct wireless bioelectronic sensors. To successfully construct wireless biological electronic sensors, there are several interesting questions: What types of biosensing transducers can be used in wireless bioelectronic sensors? What types of wireless systems can be integrated with biosensing transducers to construct wireless bioelectronic sensors? How are the electrical sensing signals generated and transmitted? This review will highlight the early attempts to address these questions in the development of wireless biological electronic sensors.

  10. Position-dependent radiative transfer as a tool for studying Anderson localization: Delay time, time-reversal and coherent backscattering

    Science.gov (United States)

    van Tiggelen, B. A.; Skipetrov, S. E.; Page, J. H.

    2017-05-01

    Previous work has established that the localized regime of wave transport in open media is characterized by a position-dependent diffusion coefficient. In this work we study how the concept of position-dependent diffusion affects the delay time, the transverse confinement, the coherent backscattering, and the time reversal of waves. Definitions of energy transport velocity of localized waves are proposed. We start with a phenomenological model of radiative transfer and then present a novel perturbational approach based on the self-consistent theory of localization. The latter allows us to obtain results relevant for realistic experiments in disordered quasi-1D wave guides and 3D slabs.

  11. High-accuracy local positioning network for the alignment of the Mu2e experiment.

    Energy Technology Data Exchange (ETDEWEB)

    Hejdukova, Jana B. [Czech Technical Univ., Prague (Czech Republic)

    2017-06-01

    This Diploma thesis describes the establishment of a high-precision local positioning network and accelerator alignment for the Mu2e physics experiment. The process of establishing new network consists of few steps: design of the network, pre-analysis, installation works, measurements of the network and making adjustments. Adjustments were performed using two approaches. First is a geodetic approach of taking into account the Earth’s curvature and the metrological approach of a pure 3D Cartesian system on the other side. The comparison of those two approaches is performed and evaluated in the results and compared with expected differences. The effect of the Earth’s curvature was found to be significant for this kind of network and should not be neglected. The measurements were obtained with Absolute Tracker AT401, leveling instrument Leica DNA03 and gyrotheodolite DMT Gyromat 2000. The coordinates of the points of the reference network were determined by the Least Square Meth od and the overall view is attached as Annexes.

  12. Is the Hegemonic Position of American Culture Able to Subjugate Local Cultures of Importing Countries? A Constructive Analysis on the Phenomenon of Cultural Localization

    Science.gov (United States)

    Chiang, Tien-Hui

    2014-01-01

    It has been argued that globalization assists the USA to gain a hegemonic position, allowing it to export its culture. Because this exportation leads to the domination by American culture of the local cultures of importing countries, which are the key element in sustaining their citizens' national identity, citizens of these countries are…

  13. Real-time stress monitoring of highway bridges with a secured wireless sensor network.

    Science.gov (United States)

    2011-12-01

    "This collaborative research aims to develop a real-time stress monitoring system for highway bridges with a secured wireless sensor network. The near term goal is to collect wireless sensor data under different traffic patterns from local highway br...

  14. On Strong Positive Frequency Dependencies of Quality Factors in Local-Earthquake Seismic Studies

    Science.gov (United States)

    Morozov, Igor B.; Jhajhria, Atul; Deng, Wubing

    2018-03-01

    Many observations of seismic waves from local earthquakes are interpreted in terms of the frequency-dependent quality factor Q( f ) = Q0 f^{η } , where η is often close to or exceeds one. However, such steep positive frequency dependencies of Q require careful analysis with regard to their physical consistency. In particular, the case of η = 1 corresponds to frequency-independent (elastic) amplitude decays with time and consequently requires no Q-type attenuation mechanisms. For η > 1, several problems with physical meanings of such Q-factors occur. First, contrary to the key premise of seismic attenuation, high-frequency parts of the wavefield are enhanced with increasing propagation times relative to the low-frequency ones. Second, such attenuation cannot be implemented by mechanical models of wave-propagating media. Third, with η > 1, the velocity dispersion associated with such Q(f) occurs over unrealistically short frequency range and has an unexpected oscillatory shape. Cases η = 1 and η > 1 are usually attributed to scattering; however, this scattering must exhibit fortuitous tuning into the observation frequency band, which appears unlikely. The reason for the above problems is that the inferred Q values are affected by the conventional single-station measurement procedure. Both parameters Q 0 and are apparent, i.e., dependent on the selected parameterization and inversion method, and they should not be directly attributed to the subsurface. For η ≈ 1, parameter Q 0 actually describes the frequency-independent amplitude decay in access of some assumed geometric spreading t -α , where α is usually taken equal one. The case η > 1 is not allowed physically and could serve as an indicator of problematic interpretations. Although the case 0 < η < 1 is possible, its parameters Q 0 and may also be biased by the measurement procedure. To avoid such difficulties of Q-based approaches, we recommend measuring and interpreting the amplitude-decay rates

  15. Downlink interference suppression of 802.11ac wireless network

    Directory of Open Access Journals (Sweden)

    WANG Huan

    2016-04-01

    Full Text Available In the 802.11ac wireless local area network,wireless intelligent devices(WID need to be connected to the network through the wireless access point(AP,and other wireless APs in the downlink transmission process will cause interference to the target WID.In this paper,we propose a method based on iterative minimum mean square error interference alignment,which can suppress the interference from the other wireless APs to the target WIDs.The wireless access terminal and wireless smart devices have designed linear precode and decode respectively.Under the minimum mean square error criterion and limitation the power constraint,optimal precode and decode can be received.Simulation results show that the proposed method,when the signal to noise ratio is 5 dB,the transmission rate of the unit bandwidth transmission rate is increased by 1 bit/s compared with the traditional Max-SINR algorithm.

  16. A Wireless Sensor Enabled by Wireless Power

    Science.gov (United States)

    Lee, Da-Sheng; Liu, Yu-Hong; Lin, Chii-Ruey

    2012-01-01

    Through harvesting energy by wireless charging and delivering data by wireless communication, this study proposes the concept of a wireless sensor enabled by wireless power (WPWS) and reports the fabrication of a prototype for functional tests. One WPWS node consists of wireless power module and sensor module with different chip-type sensors. Its main feature is the dual antenna structure. Following RFID system architecture, a power harvesting antenna was designed to gather power from a standard reader working in the 915 MHz band. Referring to the Modbus protocol, the other wireless communication antenna was integrated on a node to send sensor data in parallel. The dual antenna structure integrates both the advantages of an RFID system and a wireless sensor. Using a standard UHF RFID reader, WPWS can be enabled in a distributed area with a diameter up to 4 m. Working status is similar to that of a passive tag, except that a tag can only be queried statically, while the WPWS can send dynamic data from the sensors. The function is the same as a wireless sensor node. Different WPWSs equipped with temperature and humidity, optical and airflow velocity sensors are tested in this study. All sensors can send back detection data within 8 s. The accuracy is within 8% deviation compared with laboratory equipment. A wireless sensor network enabled by wireless power should be a totally wireless sensor network using WPWS. However, distributed WPWSs only can form a star topology, the simplest topology for constructing a sensor network. Because of shielding effects, it is difficult to apply other complex topologies. Despite this limitation, WPWS still can be used to extend sensor network applications in hazardous environments. Further research is needed to improve WPWS to realize a totally wireless sensor network. PMID:23443370

  17. A Wireless Sensor Enabled by Wireless Power

    Directory of Open Access Journals (Sweden)

    Da-Sheng Lee

    2012-11-01

    Full Text Available Through harvesting energy by wireless charging and delivering data by wireless communication, this study proposes the concept of a wireless sensor enabled by wireless power (WPWS and reports the fabrication of a prototype for functional tests. One WPWS node consists of wireless power module and sensor module with different chip-type sensors. Its main feature is the dual antenna structure. Following RFID system architecture, a power harvesting antenna was designed to gather power from a standard reader working in the 915 MHz band. Referring to the Modbus protocol, the other wireless communication antenna was integrated on a node to send sensor data in parallel. The dual antenna structure integrates both the advantages of an RFID system and a wireless sensor. Using a standard UHF RFID reader, WPWS can be enabled in a distributed area with a diameter up to 4 m. Working status is similar to that of a passive tag, except that a tag can only be queried statically, while the WPWS can send dynamic data from the sensors. The function is the same as a wireless sensor node. Different WPWSs equipped with temperature and humidity, optical and airflow velocity sensors are tested in this study. All sensors can send back detection data within 8 s. The accuracy is within 8% deviation compared with laboratory equipment. A wireless sensor network enabled by wireless power should be a totally wireless sensor network using WPWS. However, distributed WPWSs only can form a star topology, the simplest topology for constructing a sensor network. Because of shielding effects, it is difficult to apply other complex topologies. Despite this limitation, WPWS still can be used to extend sensor network applications in hazardous environments. Further research is needed to improve WPWS to realize a totally wireless sensor network.

  18. A wireless sensor enabled by wireless power.

    Science.gov (United States)

    Lee, Da-Sheng; Liu, Yu-Hong; Lin, Chii-Ruey

    2012-11-22

    Through harvesting energy by wireless charging and delivering data by wireless communication, this study proposes the concept of a wireless sensor enabled by wireless power (WPWS) and reports the fabrication of a prototype for functional tests. One WPWS node consists of wireless power module and sensor module with different chip-type sensors. Its main feature is the dual antenna structure. Following RFID system architecture, a power harvesting antenna was designed to gather power from a standard reader working in the 915 MHz band. Referring to the Modbus protocol, the other wireless communication antenna was integrated on a node to send sensor data in parallel. The dual antenna structure integrates both the advantages of an RFID system and a wireless sensor. Using a standard UHF RFID reader, WPWS can be enabled in a distributed area with a diameter up to 4 m. Working status is similar to that of a passive tag, except that a tag can only be queried statically, while the WPWS can send dynamic data from the sensors. The function is the same as a wireless sensor node. Different WPWSs equipped with temperature and humidity, optical and airflow velocity sensors are tested in this study. All sensors can send back detection data within 8 s. The accuracy is within 8% deviation compared with laboratory equipment. A wireless sensor network enabled by wireless power should be a totally wireless sensor network using WPWS. However, distributed WPWSs only can form a star topology, the simplest topology for constructing a sensor network. Because of shielding effects, it is difficult to apply other complex topologies. Despite this limitation, WPWS still can be used to extend sensor network applications in hazardous environments. Further research is needed to improve WPWS to realize a totally wireless sensor network.

  19. Implementation status of the global and local beam position feedback systems for the Advanced Photon Source storage ring

    International Nuclear Information System (INIS)

    Chung, Y.; Barr, D.; Decker, G.; Galayda, J.; Kirchman, J.; Lenkszus, F.; Lumpkin, A.; Votaw, A.J.

    1995-01-01

    The Advanced Photon Source (APS) is implementing an extensive beam position feedback system for both global and local stabilization of particle and photon beams based on digital signal processing. The description and operational experience of the system will be given in this paper. In particular, we will discuss the underlying fundamental principles, hardware layout, controls interface, and automatic software generation for multiple digital signal processors (DSPS) distributed in 20 VME crates around the ring. The feedback system runs at 4-kHz sampling frequency in order to achieve the correction bandwidth of approximately 100 Hz. For the maximum correction efficiency and resolution of conflicts among multiple local feedback systems due to the local bump closure error, the global and local feedback systems are combined into a single unified system. This novel approach is made possible through data sharing among the global and local systems via the fiber-optically networked reflective memories

  20. On Designing Thermal-Aware Localized QoS Routing Protocol for in-vivo Sensor Nodes in Wireless Body Area Networks

    OpenAIRE

    Monowar, Muhammad Mostafa; Bajaber, Fuad

    2015-01-01

    In this paper, we address the thermal rise and Quality-of-Service (QoS) provisioning issue for an intra-body Wireless Body Area Network (WBAN) having in-vivo sensor nodes. We propose a thermal-aware QoS routing protocol, called TLQoS, that facilitates the system in achieving desired QoS in terms of delay and reliability for diverse traffic types, as well as avoids the formation of highly heated nodes known as hotspot(s), and keeps the temperature rise along the network to an acceptable level....

  1. Adaptive Wireless Transceiver Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Many wireless technologies are already available for sensor applications. It is inevitable that many non-interoperable wireless technologies between 400 MHz and 5.8...

  2. Energy-efficient Organization of Wireless Sensor Networks with Adaptive Forecasting

    Directory of Open Access Journals (Sweden)

    Dao-Wei Bi

    2008-04-01

    Full Text Available Due to the wide potential applications of wireless sensor networks, this topic has attracted great attention. The strict energy constraints of sensor nodes result in great challenges for energy efficiency. This paper proposes an energy-efficient organization method. The organization of wireless sensor networks is formulated for target tracking. Target localization is achieved by collaborative sensing with multi-sensor fusion. The historical localization results are utilized for adaptive target trajectory forecasting. Combining autoregressive moving average (ARMA model and radial basis function networks (RBFNs, robust target position forecasting is performed. Moreover, an energyefficient organization method is presented to enhance the energy efficiency of wireless sensor networks. The sensor nodes implement sensing tasks are awakened in a distributed manner. When the sensor nodes transfer their observations to achieve data fusion, the routing scheme is obtained by ant colony optimization. Thus, both the operation and communication energy consumption can be minimized. Experimental results verify that the combination of ARMA model and RBFN can estimate the target position efficiently and energy saving is achieved by the proposed organization method in wireless sensor networks.

  3. Time Series Forecasting Energy-efficient Organization of Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Dao-Wei Bi

    2007-09-01

    Full Text Available Due to their wide potential applications, wireless sensor networks have recentlyreceived tremendous attention. The strict energy constraints of sensor nodes result in thegreat challenges for energy efficiency. This paper investigates the energy efficiency problemand proposes an energy-efficient organization method with time series forecasting. Theorganization of wireless sensor networks is formulated for target tracking. Target model,multi-sensor model and energy model are defined accordingly. For the target trackingapplication, target localization is achieved by collaborative sensing with multi-sensor fusion.The historical localization results are utilized for adaptive target trajectory forecasting.Empirical mode decomposition is implemented to extract the inherent variation modes in thetime series of a target trajectory. Future target position is derived from autoregressivemoving average (ARMA models, which forecast the decomposition components,respectively. Moreover, the energy-efficient organization method is presented to enhance theenergy efficiency of wireless sensor networks. The sensor nodes implement sensing tasksaccording to the probability awakening in a distributed manner. When the sensor nodestransfer their observations to achieve data fusion, the routing scheme is obtained by antcolony optimization. Thus, both the operation and communication energy consumption canbe minimized. Experimental results verify that the combination of the ARMA model andempirical mode decomposition can estimate the target position efficiently and energy savingis achieved by the proposed organization method in wireless sensor networks.

  4. Social Position Influencing the Water Perception Gap Between Local Leaders and Constituents in a Socio-Hydrological System

    Science.gov (United States)

    Haeffner, Melissa; Jackson-Smith, Douglas; Flint, Courtney G.

    2018-02-01

    How well city leaders represent their constituents and meet their needs are key concerns in transitioning to local sustainable water governance. To date, however, there is little research documenting the influence of social position between elected leaders who make policy, career staff water managers who design and operate systems and implement policies, and the members of the public whose individual water use behaviors are important drivers of water sustainability outcomes. In this study, we ask: "How does social position explain variation in water perceptions and concerns between different actors in a socio-hydrological system?" Using a mixed method approach with survey and interview data, we explore the ways that positioning within the governance system, geographic context, and citizen engagement in local government mediate perceptions of the urban water system. Regardless of local biophysical water supply conditions, residents showed most concern about future water shortages and high water costs, while their leaders were consistently most concerned about deteriorating local water infrastructure. Further, constituents who received water-related information directly from public utility mailings or served on community committees and boards had perceptions that were more aligned with leaders' concerns. The importance of social structure over natural and built environments in shaping water issue perceptions underscores the value of social analysis in socio-hydrology studies. Further, practitioners looking to increase consensus for a transition to sustainable water governance might work to develop institutional mechanisms to increase opportunities for water user involvement in local water system governance.

  5. Wireless Communication Technologies

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Wireless Communication Technologies. Since 1999, the wireless LAN has experienced a tremendous growth. Reasons: Adoption of industry standards. Interoperability testing. The progress of wireless equipments to higher data rates. Rapid decrease in product ...

  6. Application for Measurement in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Miroslav MAHDAL

    2009-06-01

    Full Text Available This paper deals with wireless sensor networks, which are based on IEEE 802.15.4 standard. The development kit from Jennic company was used for wireless measuring of values and for creation of sensor network. For this purposes the sensor boards with wireless modules with marking JN5139 were used. These boards provide sensors (sensor of temperature, relative humidity and light sensor but also another interface, which helps to develop applications. Modules are programmed in Integrated Development Environment (IDE, which integrates C function library and C++ compiler and linker. The visualization application was created for monitoring of wireless sensor network. There is the possibility of local and wireless measurement. For creation of this application the SCADA/HMI system, Control Web 5 was used. This SCADA/HMI system enables to communicate with all wireless modules through base station (network's coordinator. The application also enables initialisation and network setting the any wireless module communicating with the base station. The advantage is the remote configuration and control of network. The application also enables the gathering, converting, viewing and archiving of incoming data from particular modules.

  7. Sibling position and marriage timing in The Netherlands, 1840-1922: A comparison across social classes, local contexts and time

    NARCIS (Netherlands)

    Suanet, B.; Bras, H.

    2014-01-01

    Research on the effects of sibling position on marriage timing has produced ambivalent findings, suggesting that birth order effects were contingent on social, local, and historical contexts. Based on a large database of marriage certificates from five Dutch provinces between 1840 and 1922, we

  8. Sibling Position and Marriage Timing in the Netherlands, 1840-1922: A Comparison across Social Classes, Local Contexts, and Time

    NARCIS (Netherlands)

    Suanet, B.; Bras, H.

    2014-01-01

    Research on the effects of sibling position on marriage timing has produced ambivalent findings, suggesting that birth order effects were contingent on social, local, and historical contexts. Based on a large database of marriage certificates from five Dutch provinces between 1840 and 1922, we

  9. Improvement of local position accuracy of robots for off-line programming

    International Nuclear Information System (INIS)

    Borm, Jin Hwan; Choi, Jong Cheon

    1992-01-01

    For the implementation of industrial robots in a CIM environment, it is necessary to be able to position their end-effectors to an abstractly defined cartesian position with desired accuracy. In other words, it is necessary to find accurate actuator command values corresponding to given goal positions which are expressed with respect to a certain coordinate frame. If the teaching -by-doing method is used, very accurate actuator command values are obtained from transducer readings. For the case when the goal positions are mathematically expressed, however, the actuator command values for the goal positions must be calculated using robot kinematics. It is, however, well known that the position errors in the order of 10 mm is not unusual while many industrial robots have the repeatability in the order of 0.1mm. In here, the position error is referred to as the difference between the specified goal position and the position where a robot is actually controlled. To reduce the position errors, many researchers proposed calibration methods which are based on robot kinematic identification. However, those methods are quite complex and require an accurate position measuring device. In this paper, a new method which dose not require the accurate kinematic identification, is introduced. In this method, the accurate actuator command values are calculated using the nominal kinematic model which is appropriatly altered based on the available encoder readings of the several reference frames. To demonstrate the simplicity and the effectiveness of the method, computer simulations as well as experimental studies are performed and their results are discussed. (Author)

  10. Hyperbolic Positioning with Antenna Arrays and Multi-Channel Pseudolite for Indoor Localization

    Directory of Open Access Journals (Sweden)

    Kenjirou Fujii

    2015-09-01

    Full Text Available A hyperbolic positioning method with antenna arrays consisting of proximately-located antennas and a multi-channel pseudolite is proposed in order to overcome the problems of indoor positioning with conventional pseudolites (ground-based GPS transmitters. A two-dimensional positioning experiment using actual devices is conducted. The experimental result shows that the positioning accuracy varies centimeter- to meter-level according to the geometric relation between the pseudolite antennas and the receiver. It also shows that the bias error of the carrier-phase difference observables is more serious than their random error. Based on the size of the bias error of carrier-phase difference that is inverse-calculated from the experimental result, three-dimensional positioning performance is evaluated by computer simulation. In addition, in the three-dimensional positioning scenario, an initial value convergence analysis of the non-linear least squares is conducted. Its result shows that initial values that can converge to a right position exist at least under the proposed antenna setup. The simulated values and evaluation methods introduced in this work can be applied to various antenna setups; therefore, by using them, positioning performance can be predicted in advance of installing an actual system.

  11. Positive frozen section margins predict local recurrence in R0-resected squamous cell carcinoma of the head and neck.

    Science.gov (United States)

    Ettl, Tobias; El-Gindi, Alain; Hautmann, Matthias; Gosau, Martin; Weber, Florian; Rohrmeier, Christian; Gerken, Michael; Müller, Steffen; Reichert, Torsten; Klingelhöffer, Christoph

    2016-04-01

    The purpose of this study was to analyse the impact of surgical margins on tumour recurrence and survival of patients with carcinomas of the head and neck. A cohort of 156 patients with primary squamous cell carcinoma of the head and neck treated by local resection with negative margins and neck dissection between 2004 and 2012 was investigated. Margin status in frozen sections and permanent paraffin tissues were analysed and compared to clinical and histopathological parameters as well as to tumour recurrence (local, regional and distant) and disease-specific survival (DSS). Close margins (<5mm) on permanent sections were correlated to high-grade differentiation (p=0.070), lymphangiosis (p=0.009) and positive neck nodes (p=0.025) implicating regional and distant recurrence (p=0.001) as well as unfavorable DSS (p=0.002). Positive margins on initial frozen section analysis revised into negative margins during further surgery were the strongest predictor for local recurrence in uni- and multivariate analysis (p<0.001, hazard ratio 3.34). However, positive frozen section margins were not significantly predictive for DSS (p=0.150). Significant predictors for DSS in univariate analysis were local recurrence (p=0.026), T-stage (p=0.02), N-stage (p<0.001), grading (p=0.02) and lymphangiosis (p=0.001). Multivariate DSS analysis revealed lymph node metastasis (p=0.005) and local recurrence (p=0.017) as significant negative predictors. Close margins on permanent sections are associated with aggressive tumour characteristics, regional and distant metastasis implicating worse DSS. The accuracy of frozen section analysis seems limited as positive frozen section margins revised into negative margins bear a high risk of local recurrence. Copyright © 2016. Published by Elsevier Ltd.

  12. CCNA Wireless Study Guide

    CERN Document Server

    Lammle, Todd

    2010-01-01

    A complete guide to the CCNA Wireless exam by leading networking authority Todd Lammle. The CCNA Wireless certification is the most respected entry-level certification in this rapidly growing field. Todd Lammle is the undisputed authority on networking, and this book focuses exclusively on the skills covered in this Cisco certification exam. The CCNA Wireless Study Guide joins the popular Sybex study guide family and helps network administrators advance their careers with a highly desirable certification.: The CCNA Wireless certification is the most respected entry-level wireless certification

  13. Positive-definite functions and unitary representations of locally compact groups in a Hilbert space

    International Nuclear Information System (INIS)

    Gali, I.M.; Okb el-Bab, A.S.; Hassan, H.M.

    1977-08-01

    It is proved that the necessary and sufficient condition for the existence of an integral representation of a group of unitary operators in a Hilbert space is that it is positive-definite and continuous in some topology

  14. Real time localization of assets in hospitals using QUUPA indoor positioning technology

    NARCIS (Netherlands)

    Ham, M.F.S. van der; Zlatanova, S.; Verbree, E.; Voute, R.; Zlatanova, S.; Laurini, R.; Baucic, M.; Rumor, M.; Ellul, C.; Coors, V.

    2016-01-01

    At the most fundamental level, smart buildings deliver useful building services that make occupants productive. Smart asset management in hostipals starts with knowing the whereabouts of medical equipment. This paper investigates the subject of indoor localization of medical equipment in hospitals

  15. Proxy SDN Controller for Wireless Networks

    Directory of Open Access Journals (Sweden)

    Won-Suk Kim

    2016-01-01

    Full Text Available Management of wireless networks as well as wired networks by using software-defined networking (SDN has been highlighted continually. However, control features of a wireless network differ from those of a wired network in several aspects. In this study, we identify the various inefficient points when controlling and managing wireless networks by using SDN and propose SDN-based control architecture called Proxcon to resolve these problems. Proxcon introduces the concept of a proxy SDN controller (PSC for the wireless network control, and the PSC entrusted with the role of a main controller performs control operations and provides the latest network state for a network administrator. To address the control inefficiency, Proxcon supports offloaded SDN operations for controlling wireless networks by utilizing the PSC, such as local control by each PSC, hybrid control utilizing the PSC and the main controller, and locally cooperative control utilizing the PSCs. The proposed architecture and the newly supported control operations can enhance scalability and response time when the logically centralized control plane responds to the various wireless network events. Through actual experiments, we verified that the proposed architecture could address the various control issues such as scalability, response time, and control overhead.

  16. The art of wireless sensor networks

    CERN Document Server

    2014-01-01

    During the last one and a half decades, wireless sensor networks have witnessed significant growth and tremendous development in both academia and industry.   “The Art of Wireless Sensor Networks: Volume 1: Fundamentals” focuses on the fundamentals concepts in the design, analysis, and implementation of wireless sensor networks. It covers the various layers of the lifecycle of this type of network from the physical layer up to the application layer. Its rationale is that the first volume covers contemporary design issues, tools, and protocols for radio-based two-dimensional terrestrial sensor networks. All the book chapters in this volume include up-to-date research work spanning various classic facets of the physical properties and functional behavior of wireless sensor networks, including physical layer, medium access control, data routing, topology management, mobility management, localization, task management, data management, data gathering, security, middleware, sensor technology, standards, and ...

  17. Outcome of wide local excision in dermatofibrosarcoma protuberans and use of radiotherapy for margin-positive disease

    Directory of Open Access Journals (Sweden)

    Raashid Hamid

    2013-01-01

    Full Text Available Purpose: Wide local excision (WLE is the preferred treatment of dermatofibrosarcoma protuberans (DFSP. The aim is to achieve negtive margins. We followed the impact of radiotherapy used postoperatively for both margin-negative and margin-positive DFSP tumors. Materials and Methods: Outcome of treatment of 36 patients of DFSP treated at our hospital was assessed. Thirty patients received radiotherapy postoperatively and six patients received radiotherapy alone. The maximum dimension of the lesion was 15 cm 2 . Patients were followed up for varying periods of time for any recurrence. Results: 10-year actuarial local control rate was determined. Local control was realized in six patients who were treated with radiotherapy alone. 30 patients were treated by radiotherapy and surgery. Out of these 30 patients, there were 6 local failures (failure rate 10%. Actuarial control rate was 82%. The failures were among patients who had positive margins. Conclusion: Radiotherapy is effective, and it decreases the recurrence rate in the treatment of DFSP. It is especially helpful in margin-positive disease. This appears true for patients treated with radiotherapy alone or radiotherapy used postoperatively.

  18. LEARNING WHICH ORIENTED ON LOCAL WISDOM TO GROW A POSITIVE APPRECIATION OF BATIK JUMPUTAN (IKAT CELUP METHOD

    Directory of Open Access Journals (Sweden)

    S. E. Atmojo

    2015-04-01

    Full Text Available This study aims to identify the elements of science in the process of batik jumputan as the local culture. By knowing the existence of the elements of science in batik jumputan, expected to foster a positive appreciation of batik jumputan as a local cultural heritage. Based on the results of questionnaire analysis, we know that the growing appreciation before and after learning of the profession WHO batik makers are at high criterion (0.70 g. The results of the observation science process skills while making batik we can conclude it to the average score of science process skills (60% KPS 80% are located in the high category.

  19. The Role of Wireless Computing Technology in the Design of Schools.

    Science.gov (United States)

    Nair, Prakash

    This document discusses integrating computers logically and affordably into a school building's infrastructure through the use of wireless technology. It begins by discussing why wireless networks using mobile computers are preferable to desktop machines in each classoom. It then explains the features of a wireless local area network (WLAN) and…

  20. The Efficacy of Neoadjuvant Chemotherapy for HER-2-Positive Locally Advanced Breast Cancer and Survival Analysis

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2017-01-01

    Full Text Available To provide reference data, we retrospectively investigated the effects of neoadjuvant chemotherapy (NAC on 119 patients with HER-2+ locally advanced breast cancer, treated from November 2010 to July 2016, with respect to influencing factors and survival. They were divided into the pathological complete response (pCR; n=15; 12.6% and non-pCR (n=104; 87.4% groups. We used Χ2 and logistic tests to the analyze effect and influencing factors. Survival rate was analyzed by the Kaplan-Meier method and Log-rank test. We lost 12 patients (including 1 pCR patient and followed 107 patients, of whom 31 (all in the non-pCR group had local recurrences or distant metastasis. The two groups significantly differed in 3-year disease-free survival (pCR group: 100%; non-pCR group: 59.0%; P=0.039; pCR was significantly affected by histological grade, PR status, Ki67 index, primary tumor size, clinical staging, and number of trastuzumab cycles. The model was tested, and the difference was statistically significant (Χ2 = 31.938, P=0.032. Patients with HER-2+ locally advanced breast cancer with pCR responses to NAC have improved prognoses. Patients without pCR have increased risk for relapse. The use of a combination of NAC, such as trastuzumab and chemotherapy, and more cycles should be considered to increase the likelihood of pCR.

  1. The impact of a focally positive resection margin on the local control in patients treated with breast-conserving therapy

    International Nuclear Information System (INIS)

    Park, Seho; Park, Hyung-Seok; Kim, Seung-ll; Koo, Ja-Seung; Park, Byeong-Woo; Lee, Kyong-Sik

    2011-01-01

    The aim of the study was to investigate the parameters affecting positive margin and the impact of positive margin on outcomes after breast-conserving therapy in patients with breast cancer. Characteristics and survival of 705 patients attempted breast-conserving therapy between January 1994 and December 2004 were retrospectively analyzed using χ 2 tests, the Kaplan-Meier methods and multivariate analyses. Ninety-five (13.5%) showed positive margins at initial resection. Among them, 28 (4.0%) had negative margin on the initial frozen section; however, they finally turned out a focally positive margin with intraductal carcinoma on the permanent pathology. Positive margin at initial resection was significantly associated with lobular histology (P=0.001), four or more involved lymph nodes (P=0.015) and the presence of extensive intraductal component (P<0.001). A focally positive margin did not influence local (P=0.250; 95% confidence interval, 0.612-6.592) or regional failure (P=0.756; 95% confidence interval, 0.297-5.311). Patients with a focally positive margin showed an advanced nodal stage and received a higher dose of irradiation and more systemic therapy. Nodal involvements were the most significant factor for locoregional failure. Although the achievement of negative margins is the best way to reduce local failure, patients with a focally positive margin and favorable risk factors such as node negativity and older age could have an option of close follow-up with adequate boost irradiation and adjuvant therapy instead of conversion to total mastectomy. (author)

  2. The Impact of Definitive Local Therapy for Lymph Node-Positive Prostate Cancer: A Population-Based Study

    International Nuclear Information System (INIS)

    Rusthoven, Chad G.; Carlson, Julie A.; Waxweiler, Timothy V.; Raben, David; Dewitt, Peter E.; Crawford, E. David; Maroni, Paul D.; Kavanagh, Brian D.

    2014-01-01

    Purpose: To evaluate the survival outcomes for patients with lymph node-positive, nonmetastatic prostate cancer undergoing definitive local therapy (radical prostatectomy [RP], external beam radiation therapy [EBRT], or both) versus no local therapy (NLT) in the US population in the modern prostate specific antigen (PSA) era. Methods and Materials: The Surveillance, Epidemiology, and End Results database was queried for patients with T1-4N1M0 prostate cancer diagnosed from 1995 through 2005. To allow comparisons of equivalent datasets, patients were analyzed in separate clinical (cN+) and pathologically confirmed (pN+) lymph node-positive cohorts. Kaplan-Meier overall survival (OS) and prostate cancer-specific survival (PCSS) estimates were generated, with accompanying univariate log-rank and multivariate Cox proportional hazards comparisons. Results: A total of 796 cN+ and 2991 pN+ patients were evaluable. Among cN+ patients, 43% underwent EBRT and 57% had NLT. Outcomes for cN+ patients favored EBRT, with 10-year OS rates of 45% versus 29% (P<.001) and PCSS rates of 67% versus 53% (P<.001). Among pN+ patients, 78% underwent local therapy (RP 57%, EBRT 10%, or both 11%) and 22% had NLT. Outcomes for pN+ also favored local therapy, with 10-year OS rates of 65% versus 42% (P<.001) and PCSS rates of 78% versus 56% (P<.001). On multivariate analysis, local therapy in both the cN+ and pN+ cohorts remained independently associated with improved OS and PCSS (all P<.001). Local therapy was associated with favorable hazard ratios across subgroups, including patients aged ≥70 years and those with multiple positive lymph nodes. Among pN+ patients, no significant differences in survival were observed between RP versus EBRT and RP with or without adjuvant EBRT. Conclusions: In this large, population-based cohort, definitive local therapy was associated with significantly improved survival in patients with lymph node-positive prostate cancer

  3. The Impact of Definitive Local Therapy for Lymph Node-Positive Prostate Cancer: A Population-Based Study

    Energy Technology Data Exchange (ETDEWEB)

    Rusthoven, Chad G., E-mail: chad.rusthoven@ucdenver.edu [Department of Radiation Oncology, University of Colorado-Denver, Aurora, Colorado (United States); Carlson, Julie A.; Waxweiler, Timothy V.; Raben, David [Department of Radiation Oncology, University of Colorado-Denver, Aurora, Colorado (United States); Dewitt, Peter E. [Department of Biostatistics, University of Colorado-Denver, Aurora, Colorado (United States); Crawford, E. David [Department of Radiation Oncology, University of Colorado-Denver, Aurora, Colorado (United States); Department of Urology, University of Colorado-Denver, Aurora, Colorado (United States); Maroni, Paul D. [Department of Urology, University of Colorado-Denver, Aurora, Colorado (United States); Kavanagh, Brian D. [Department of Radiation Oncology, University of Colorado-Denver, Aurora, Colorado (United States)

    2014-04-01

    Purpose: To evaluate the survival outcomes for patients with lymph node-positive, nonmetastatic prostate cancer undergoing definitive local therapy (radical prostatectomy [RP], external beam radiation therapy [EBRT], or both) versus no local therapy (NLT) in the US population in the modern prostate specific antigen (PSA) era. Methods and Materials: The Surveillance, Epidemiology, and End Results database was queried for patients with T1-4N1M0 prostate cancer diagnosed from 1995 through 2005. To allow comparisons of equivalent datasets, patients were analyzed in separate clinical (cN+) and pathologically confirmed (pN+) lymph node-positive cohorts. Kaplan-Meier overall survival (OS) and prostate cancer-specific survival (PCSS) estimates were generated, with accompanying univariate log-rank and multivariate Cox proportional hazards comparisons. Results: A total of 796 cN+ and 2991 pN+ patients were evaluable. Among cN+ patients, 43% underwent EBRT and 57% had NLT. Outcomes for cN+ patients favored EBRT, with 10-year OS rates of 45% versus 29% (P<.001) and PCSS rates of 67% versus 53% (P<.001). Among pN+ patients, 78% underwent local therapy (RP 57%, EBRT 10%, or both 11%) and 22% had NLT. Outcomes for pN+ also favored local therapy, with 10-year OS rates of 65% versus 42% (P<.001) and PCSS rates of 78% versus 56% (P<.001). On multivariate analysis, local therapy in both the cN+ and pN+ cohorts remained independently associated with improved OS and PCSS (all P<.001). Local therapy was associated with favorable hazard ratios across subgroups, including patients aged ≥70 years and those with multiple positive lymph nodes. Among pN+ patients, no significant differences in survival were observed between RP versus EBRT and RP with or without adjuvant EBRT. Conclusions: In this large, population-based cohort, definitive local therapy was associated with significantly improved survival in patients with lymph node-positive prostate cancer.

  4. Localization pattern of conjugation machinery in a Gram-positive bacterium.

    Science.gov (United States)

    Bauer, Theresa; Rösch, Thomas; Itaya, Mitsuhiro; Graumann, Peter L

    2011-11-01

    Conjugation is an efficient way for transfer of genetic information between bacteria, even between highly diverged species, and a major cause for the spreading of resistance genes. We have investigated the subcellular localization of several conserved conjugation proteins carried on plasmid pLS20 found in Bacillus subtilis. We show that VirB1, VirB4, VirB11, VirD2, and VirD4 homologs assemble at a single cell pole, but also at other sites along the cell membrane, in cells during the lag phase of growth. Bimolecular fluorescence complementation analyses showed that VirB4 and VirD4 interact at the cell pole and, less frequently, at other sites along the membrane. VirB1 and VirB11 also colocalized at the cell pole. Total internal reflection fluorescence microscopy showed that pLS20 is largely membrane associated and is frequently found at the cell pole, indicating that transfer takes place at the pole, which is a preferred site for the assembly of the active conjugation apparatus, but not the sole site. VirD2, VirB4, and VirD4 started to localize to the pole or the membrane in stationary-phase cells, and VirB1 and VirB11 were observed as foci in cells resuspended in fresh medium but no longer in cells that had entered exponential growth, although at least VirB4 was still expressed. These data reveal an unusual assembly/disassembly timing for the pLS20 conjugation machinery and suggest that specific localization of conjugation proteins in lag-phase cells and delocalization during growth are the reasons why pLS20 conjugation occurs only during early exponential phase.

  5. Drexel Goes Wireless: Leading U.S. University Creates Fully Wireless Cyber Campus

    OpenAIRE

    Blackney, Ken; Bielec, John

    2001-01-01

    In 1997 Drexel began implementing its first CyberZone -- an area of continuous wireless network connectivity. Begun as a pilot project in the central library, CyberZones quickly proved to be both popular and practical. In 2000 Drexel became the first major university to implement a campus-wide, high-speed wireless network for all indoor and outdoor areas, including public spaces such as local train platforms and nearby cafes and restaurants. This presentation describes the technical, politica...

  6. Measuring the value of the city brand and its position in the minds of users of local services

    Directory of Open Access Journals (Sweden)

    Miljanović Mirjana P.

    2016-01-01

    Full Text Available Cities compete with each other in order to attract more tourists, investors, businesses or residents today. Therefore, more and more attention is paid to the brand building and promotion of the city to the users of local services. However, the perception of the city (brand can drastically vary among the users. The goal of this paper is to explore how the city of Trebinje is positioned in the minds of local services users. Determination of the status, image, and value of the city brand was carried out on the example of the city of Trebinje using Anholt-GfK Roper City Brands Index. Sample consisted of 505 respondents with four groups of local services users: residents, tourists, businessman, and investors. Key information is obtained from data processing after the survey, i.e. analysis of data obtained from questionnaires prepared for the purposes of this research.

  7. Design and Implementation of an Ultrasonic Local Positioning System for Robot Guidance in a Heavy Liquid Metal Environment

    International Nuclear Information System (INIS)

    De-Cock, Wouter; Kenis, Steven; Van-Roy, Ken; Verachtert, Lieven; Leroux, Paul

    2013-06-01

    In this paper, we describe a preliminary research towards the use of chirp coded spread spectrum techniques to implement a local positioning system to assist robot operators during manipulations and maintenance tasks in the future MYRRHA reactor. Preliminary test results in a simple experimental setup show promising results towards further developments of the system as the developed algorithms are able to discriminate between different transducers. (authors)

  8. Signatures of positive selection and local adaptation to urbanization in white-footed mice (Peromyscus leucopus).

    Science.gov (United States)

    Harris, Stephen E; Munshi-South, Jason

    2017-11-01

    Urbanization significantly alters natural ecosystems and has accelerated globally. Urban wildlife populations are often highly fragmented by human infrastructure, and isolated populations may adapt in response to local urban pressures. However, relatively few studies have identified genomic signatures of adaptation in urban animals. We used a landscape genomic approach to examine signatures of selection in urban populations of white-footed mice (Peromyscus leucopus) in New York City. We analysed 154,770 SNPs identified from transcriptome data from 48 P. leucopus individuals from three urban and three rural populations and used outlier tests to identify evidence of urban adaptation. We accounted for demography by simulating a neutral SNP data set under an inferred demographic history as a null model for outlier analysis. We also tested whether candidate genes were associated with environmental variables related to urbanization. In total, we detected 381 outlier loci and after stringent filtering, identified and annotated 19 candidate loci. Many of the candidate genes were involved in metabolic processes and have well-established roles in metabolizing lipids and carbohydrates. Our results indicate that white-footed mice in New York City are adapting at the biomolecular level to local selective pressures in urban habitats. Annotation of outlier loci suggests selection is acting on metabolic pathways in urban populations, likely related to novel diets in cities that differ from diets in less disturbed areas. © 2017 John Wiley & Sons Ltd.

  9. Local governance from A to Z - Positive glossary of the energy transition

    International Nuclear Information System (INIS)

    Eisermann, Miriam; Donnerer, David; Morel, Diane

    2015-12-01

    This publication invites you to discover the multiple facets of a collaborative city from A-Z, based on our over 25 years' experience of what works well in Europe. The list is, of course, not exhaustive as the beauty of energy transition is the wide and unlimited field of possibilities that it opens up. What it is proposing however is a change of perspective. As the energy landscape is undergoing radical change, from a once hierarchical and monopolistic system to a more distributed and decentralised one, so too should the decision-making architecture. Indeed, a new system cannot be designed using outdated models: in writing a new chapter of our history, we must also empower its new stakeholders. We, the local and regional actors, are these new players, through the role we play in mobilizing civil society and SMEs, tapping into the large array of dispersed renewable or locally recovered energy sources and increasing energy savings and efficiency through ambitious building, urban planning and mobility strategies. This publication complements Energy Cities' '30 proposals for the energy transition of cities' with its many case studies

  10. Acute changes in intra-alveolar tooth position and local clearance of 125I from the periodontal ligament

    International Nuclear Information System (INIS)

    Edwall, B.; Berg, J.O.; Gazelius, B.; Edwall, L.; Aars, H.

    1987-01-01

    Changes in intra-alveolar tooth position and local 125 I clearance from the periodontal ligament (PDL) were monitored simultaneously in cats. Axial tooth movements, reflecting periodontal ligament volume changes, were measured with an ultrasonic transit time technique. Local blood flow changes in the PDL were studied indirectly by measuring the local clearance of 125 I. Stimulation of the cervical sympathetic trunk caused an intrusive movement of the tooth with a concomitant reduction of the 125 I-clearance. Infusion of noradrenaline induced a similar respone. Stimulation of the inferior alveolar nerve during systemic treatment with phentolamine caused an extrusive movement of the tooth with a concomitant increase in the clearance of the tracer from the PDL. Intra-arterial infusion of the vasodilator substance P mimicked that response. Fization of the tooth to the jaw bone, thus preventing an intrusive movement, did not change the reductions in clearance seen on sympathetic stimulation, indicating that this blood flow reduction was not dependent on tooth movement. A qualitative relation between PDL blood flow (as measured by local 125 I clearance) and PDL volume (as measured by tooth position) in shown. The two variables measured are suggested to reflect two aspects of blood flow in the PDL

  11. Optimizing heliostat positions with local search metaheuristics using a ray tracing optical model

    Science.gov (United States)

    Reinholz, Andreas; Husenbeth, Christof; Schwarzbözl, Peter; Buck, Reiner

    2017-06-01

    The life cycle costs of solar tower power plants are mainly determined by the investment costs of its construction. Significant parts of these investment costs are used for the heliostat field. Therefore, an optimized placement of the heliostats gaining the maximal annual power production has a direct impact on the life cycle costs revenue ratio. We present a two level local search method implemented in MATLAB utilizing the Monte Carlo raytracing software STRAL [1] for the evaluation of the annual power output for a specific weighted annual time scheme. The algorithm was applied to a solar tower power plant (PS10) with 624 heliostats. Compared to former work of Buck [2], we were able to improve both runtime of the algorithm and quality of the output solutions significantly. Using the same environment for both algorithms, we were able to reach Buck's best solution with a speed up factor of about 20.

  12. Positive ground state solutions to Schrodinger-Poisson systems with a negative non-local term

    Directory of Open Access Journals (Sweden)

    Yan-Ping Gao

    2015-04-01

    Full Text Available In this article, we study the Schrodinger-Poisson system $$\\displaylines{ -\\Delta u+u-\\lambda K(x\\phi(xu=a(x|u|^{p-1}u, \\quad x\\in\\mathbb{R}^3, \\cr -\\Delta\\phi=K(xu^{2},\\quad x\\in\\mathbb{R}^3, }$$ with $p\\in(1,5$. Assume that $a:\\mathbb{R}^3\\to \\mathbb{R^{+}}$ and $K:\\mathbb{R}^3\\to \\mathbb{R^{+}}$ are nonnegative functions and satisfy suitable assumptions, but not requiring any symmetry property on them, we prove the existence of a positive ground state solution resolved by the variational methods.

  13. Unsweetened ice popsicles impart a positive feeling and reduce self-mutilation after paediatric dental treatment with local anaesthesia.

    Science.gov (United States)

    Ram, Diana; Berson, Tamar; Moskovitz, Moti; Efrat, Jacob

    2010-09-01

    The purpose of the current study was to assess whether an unsweetened ice-popsicle imparts a positive feeling to children after dental treatment in which local anaesthesia is administered, and whether it reduces the tendency of children to self-mutilate (bite the lip, cheek or tongue) after the administration of local anaesthesia. Crossover study of 31 children aged 4-11 years old who needed similar dental treatments on both sides of the mandible or maxilla under local anaesthesia. At the end of each appointment the child received a toy or an ice-popsicle especially made for this study. Patients and parents answered a questionnaire regarding the children's behaviour and feeling immediately after the treatment, and 10 and 30 min after receiving the ice-popsicle or toy. Children who received ice-popsicles after dental treatment under local anaesthesia felt less discomfort and suffered less soft tissue trauma than they did when they received a toy. Reduction in soft tissue trauma was evident 10 min after receiving the ice-popsicles. Licking of an ice-popsicle after dental treatment with local anaesthesia reduces the feeling of discomfort and the biting of soft tissue and self- mutilation.

  14. Validity of an ultra-wideband local positioning system to measure locomotion in indoor sports.

    Science.gov (United States)

    Serpiello, F R; Hopkins, W G; Barnes, S; Tavrou, J; Duthie, G M; Aughey, R J; Ball, K

    2018-08-01

    The validity of an Ultra-wideband (UWB) positioning system was investigated during linear and change-of-direction (COD) running drills. Six recreationally-active men performed ten repetitions of four activities (walking, jogging, maximal acceleration, and 45º COD) on an indoor court. Activities were repeated twice, in the centre of the court and on the side. Participants wore a receiver tag (Clearsky T6, Catapult Sports) and two reflective markers placed on the tag to allow for comparisons with the criterion system (Vicon). Distance, mean and peak velocity, acceleration, and deceleration were assessed. Validity was assessed via percentage least-square means difference (Clearsky-Vicon) with 90% confidence interval and magnitude-based inference; typical error was expressed as within-subject standard deviation. The mean differences for distance, mean/peak speed, and mean/peak accelerations in the linear drills were in the range of 0.2-12%, with typical errors between 1.2 and 9.3%. Mean and peak deceleration had larger differences and errors between systems. In the COD drill, moderate-to-large differences were detected for the activity performed in the centre of the court, increasing to large/very large on the side. When filtered and smoothed following a similar process, the UWB-based positioning system had acceptable validity, compared to Vicon, to assess movements representative of indoor sports.

  15. A prospective clinical study to evaluate the safety and performance of wireless localization of nonpalpable breast lesions using radiofrequency identification technology.

    Science.gov (United States)

    Dauphine, Christine; Reicher, Joshua J; Reicher, Murray A; Gondusky, Christina; Khalkhali, Iraj; Kim, Michelle

    2015-06-01

    The purpose of this study was to evaluate the safety and performance of localizing nonpalpable breast lesions using radiofrequency identification technology. Twenty consecutive women requiring preoperative localization of a breast lesion were recruited. Subjects underwent placement of both a hook wire and a radiofrequency identification tag immediately before surgery. The radiofrequency identification tag was the primary method used by the operating surgeon to localize each lesion during excision, with the hook wire serving as backup in case of tag migration or failed localization. Successful localization with removal of the intended lesion was the primary outcome measured. Tag migration and postoperative infection were also noted to assess safety. Twenty patients underwent placement of a radiofrequency identification tag, 12 under ultrasound guidance and eight with stereotactic guidance. In all cases, the radiofrequency identification tag was successfully localized by the reader at the level of the skin before incision, and the intended lesion was removed along with the radiofrequency identification tag. There were no localization failures and no postoperative infections. Tag migration did not occur before incision, but in three cases, occurred as the lesion was being retracted with fingers to make the final cut along the deep surface of the specimen. In this initial clinical study, radiofrequency tags were safe and able to successfully localize nonpalpable breast lesions. Radiofrequency identification technology may represent an alternative method to hook wire localization.

  16. Wireless physical layer security

    OpenAIRE

    Poor, H. Vincent; Schaefer, Rafael F.

    2016-01-01

    Security is a very important issue in the design and use of wireless networks. Traditional methods of providing security in such networks are impractical for some emerging types of wireless networks due to the light computational abilities of some wireless devices [such as radio-frequency identification (RFID) tags, certain sensors, etc.] or to the very large scale or loose organizational structure of some networks. Physical layer security has the potential to address these concerns by taking...

  17. Intrinsic spatial resolution limitations due to differences between positron emission position and annihilation detection localization

    International Nuclear Information System (INIS)

    Perez, Pedro; Malano, Francisco; Valente, Mauro

    2012-01-01

    Since its successful implementation for clinical diagnostic, positron emission tomography (PET) represents the most promising medical imaging technique. The recent major growth of PET imaging is mainly due to its ability to trace the biologic pathways of different compounds in the patient's body, assuming the patient can be labeled with some PET isotope. Regardless of the type of isotope, the PET imaging method is based on the detection of two 511-keV gamma photons being emitted in opposite directions, with almost 180 deg between them, as a consequence of electron-positron annihilation. Therefore, this imaging method is intrinsically limited by random uncertainties in spatial resolutions, related with differences between the actual position of positron emission and the location of the detected annihilation. This study presents an approach with the Monte Carlo method to analyze the influence of this effect on different isotopes of potential implementation in PET. (author)

  18. Risk factors associated with positive surgical margins following radical prostatectomy for clinically localized prostate cancer

    DEFF Research Database (Denmark)

    Røder, Martin Andreas; Thomsen, Frederik Birkebæk; Christensen, Ib Jarle

    2014-01-01

    consecutive single-institution Danish cohort of 1148 patients undergoing RP between 1995 and 2011 was investigated. To analyse the impact of covariates on risk of PSM, a multivariate logistic regression model was used, including cT category, biopsy Gleason score, prostate-specific antigen (PSA), percentage...... positive biopsies for cancer (PPB), surgeon and surgical technique. RESULTS: The overall rate of PSM was 31.4%. The risk of PSM depended (p value for Wald χ(2)) on PSA (p PSA, the risk of PSM...... to the referent surgeon. Nerve-sparing surgery increased the risk of PSM by 50% compared to wide resection (OR = 1.5, 95% CI 1.0-2.1, p = 0.03). CONCLUSION: Both preoperative and surgical parameters affect the risk of PSM after radical prostatectomy. Surgeon and high preoperative PSA, PPB and cT category were...

  19. EBV-positive mucocutaneous ulcer in organ transplant recipients: a localized indolent posttransplant lymphoproliferative disorder.

    Science.gov (United States)

    Hart, Melissa; Thakral, Beenu; Yohe, Sophia; Balfour, Henry H; Singh, Charanjeet; Spears, Michael; McKenna, Robert W

    2014-11-01

    Epstein-Barr virus (EBV)-positive mucocutaneous ulcer (EBV MCU) is a B-cell lymphoproliferative disorder occurring in elderly or iatrogenic immunocompromised patients. It has not been reported in solid organ transplant recipients. We observed 7 patients with EBV MCU in a cohort of 70 transplant recipients with EBV posttransplant lymphoproliferative disorder (PTLD). Transplants included: 5 renal, 1 heart, and 1 lung. Median patient age was 61; 5 were male. EBV MCU was observed in oral mucosa in 4 and gastrointestinal tract in 3. Duration of immunosuppressive therapy before EBV MCU was 0.6 to 13 years. Ulcers were undermined by inflammatory cells and polymorphic or monomorphic large cell lymphoproliferation. Reed-Sternberg-like cells were present in 5/7. Large B cells were CD20, CD30, and EBV-encoded RNA positive in all cases. Diagnosis in 3 recent patients was EBV MCU; 4 patients diagnosed before familiarity with EBV MCU were classified as monomorphic large cell (n=3) and polymorphic (n=1) PTLD. None of the patients had EBV DNA in their blood (<1000 copies/mL) at diagnosis or follow-up versus 35/44 transplant patients with systemic PTLD (P<0.001). All lesions resolved with reduced immunosuppression (7/7), change in immunosuppression (2/7), and rituximab (3/7). Five patients are living: 4 healthy, 1 awaiting second renal transplant. Two patients died 3 and 5 years after resolution of EBV MCU. No patient recurred with EBV MCU or other PTLDs. EBV MCU mimics more aggressive categories of PTLD but lacks EBV DNA in blood, which may be a useful distinguishing feature. Lesions are likely to resolve with conservative management. Awareness of EBV MCU in the posttransplant setting is necessary for appropriate diagnosis and treatment.

  20. Non-linear elasticity of extracellular matrices enables contractile cells to communicate local position and orientation.

    Directory of Open Access Journals (Sweden)

    Jessamine P Winer

    2009-07-01

    Full Text Available Most tissue cells grown in sparse cultures on linearly elastic substrates typically display a small, round phenotype on soft substrates and become increasingly spread as the modulus of the substrate increases until their spread area reaches a maximum value. As cell density increases, individual cells retain the same stiffness-dependent differences unless they are very close or in molecular contact. On nonlinear strain-stiffening fibrin gels, the same cell types become maximally spread even when the low strain elastic modulus would predict a round morphology, and cells are influenced by the presence of neighbors hundreds of microns away. Time lapse microscopy reveals that fibroblasts and human mesenchymal stem cells on fibrin deform the substrate by several microns up to five cell lengths away from their plasma membrane through a force limited mechanism. Atomic force microscopy and rheology confirm that these strains locally and globally stiffen the gel, depending on cell density, and this effect leads to long distance cell-cell communication and alignment. Thus cells are acutely responsive to the nonlinear elasticity of their substrates and can manipulate this rheological property to induce patterning.

  1. Wireless Emulation Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Wireless Emulation Laboratory (WEL) is a researchtest bed used to investigate fundamental issues in networkscience. It is a research infrastructure that emulates...

  2. Adaptive Wireless Transceiver Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Wireless technologies are an increasingly attractive means for spatial data, input, manipulation, and distribution. Mobitrum is proposing an innovative Adaptive...

  3. Ad-Coop Positioning System (ACPS)

    DEFF Research Database (Denmark)

    Frattasi, Simone; Monti, Marco

    2008-01-01

    In this paper, we propose an innovative solution for positioning determination in 4G wireless networks by introducing the Ad-Coop Positioning System (ACPS). The ACPS is supported by a hybrid cellular ad-hoc architecture, where the cellular network has a centralized control over the ad......-hoc connections among pairs of mobiles. Specifically, peer-to-peer (P2P) communications are exploited in a mesh fashion within cellular-established clusters for cooperation-aided localization purposes (from that, the word ad-coop is derived). The major contribution of this work is the design of the data fusion...... to conventional hybrid positioning techniques in cellular networks....

  4. Accurate statistics for local sequence alignment with position-dependent scoring by rare-event sampling

    Directory of Open Access Journals (Sweden)

    Rahmann Sven

    2011-02-01

    Full Text Available Abstract Background Molecular database search tools need statistical models to assess the significance for the resulting hits. In the classical approach one asks the question how probable a certain score is observed by pure chance. Asymptotic theories for such questions are available for two random i.i.d. sequences. Some effort had been made to include effects of finite sequence lengths and to account for specific compositions of the sequences. In many applications, such as a large-scale database homology search for transmembrane proteins, these models are not the most appropriate ones. Search sensitivity and specificity benefit from position-dependent scoring schemes or use of Hidden Markov Models. Additional, one may wish to go beyond the assumption that the sequences are i.i.d. Despite their practical importance, the statistical properties of these settings have not been well investigated yet. Results In this paper, we discuss an efficient and general method to compute the score distribution to any desired accuracy. The general approach may be applied to different sequence models and and various similarity measures that satisfy a few weak assumptions. We have access to the low-probability region ("tail" of the distribution where scores are larger than expected by pure chance and therefore relevant for practical applications. Our method uses recent ideas from rare-event simulations, combining Markov chain Monte Carlo simulations with importance sampling and generalized ensembles. We present results for the score statistics of fixed and random queries against random sequences. In a second step, we extend the approach to a model of transmembrane proteins, which can hardly be described as i.i.d. sequences. For this case, we compare the statistical properties of a fixed query model as well as a hidden Markov sequence model in connection with a position based scoring scheme against the classical approach. Conclusions The results illustrate that the

  5. Mathematical Model and Calibration Procedure of a PSD Sensor Used in Local Positioning Systems.

    Science.gov (United States)

    Rodríguez-Navarro, David; Lázaro-Galilea, José Luis; Bravo-Muñoz, Ignacio; Gardel-Vicente, Alfredo; Domingo-Perez, Francisco; Tsirigotis, Georgios

    2016-09-15

    Here, we propose a mathematical model and a calibration procedure for a PSD (position sensitive device) sensor equipped with an optical system, to enable accurate measurement of the angle of arrival of one or more beams of light emitted by infrared (IR) transmitters located at distances of between 4 and 6 m. To achieve this objective, it was necessary to characterize the intrinsic parameters that model the system and obtain their values. This first approach was based on a pin-hole model, to which system nonlinearities were added, and this was used to model the points obtained with the nA currents provided by the PSD. In addition, we analyzed the main sources of error, including PSD sensor signal noise, gain factor imbalances and PSD sensor distortion. The results indicated that the proposed model and method provided satisfactory calibration and yielded precise parameter values, enabling accurate measurement of the angle of arrival with a low degree of error, as evidenced by the experimental results.

  6. SmartMIMO: An Energy-Aware Adaptive MIMO-OFDM Radio Link Control for Next-Generation Wireless Local Area Networks

    Directory of Open Access Journals (Sweden)

    Dehaene Wim

    2007-01-01

    Full Text Available Multiantenna systems and more particularly those operating on multiple input and multiple output (MIMO channels are currently a must to improve wireless links spectrum efficiency and/or robustness. There exists a fundamental tradeoff between potential spectrum efficiency and robustness increase. However, multiantenna techniques also come with an overhead in silicon implementation area and power consumption due, at least, to the duplication of part of the transmitter and receiver radio front-ends. Although the area overhead may be acceptable in view of the performance improvement, low power consumption must be preserved for integration in nomadic devices. In this case, it is the tradeoff between performance (e.g., the net throughput on top of the medium access control layer and average power consumption that really matters. It has been shown that adaptive schemes were mandatory to avoid that multiantenna techniques hamper this system tradeoff. In this paper, we derive smartMIMO: an adaptive multiantenna approach which, next to simply adapting the modulation and code rate as traditionally considered, decides packet-per-packet, depending on the MIMO channel state, to use either space-division multiplexing (increasing spectrum efficiency, space-time coding (increasing robustness, or to stick to single-antenna transmission. Contrarily to many of such adaptive schemes, the focus is set on using multiantenna transmission to improve the link energy efficiency in real operation conditions. Based on a model calibrated on an existing reconfigurable multiantenna transceiver setup, the link energy efficiency with the proposed scheme is shown to be improved by up to 30% when compared to nonadaptive schemes. The average throughput is, on the other hand, improved by up to 50% when compared to single-antenna transmission.

  7. SmartMIMO: An Energy-Aware Adaptive MIMO-OFDM Radio Link Control for Next-Generation Wireless Local Area Networks

    Directory of Open Access Journals (Sweden)

    Wim Dehaene

    2007-12-01

    Full Text Available Multiantenna systems and more particularly those operating on multiple input and multiple output (MIMO channels are currently a must to improve wireless links spectrum efficiency and/or robustness. There exists a fundamental tradeoff between potential spectrum efficiency and robustness increase. However, multiantenna techniques also come with an overhead in silicon implementation area and power consumption due, at least, to the duplication of part of the transmitter and receiver radio front-ends. Although the area overhead may be acceptable in view of the performance improvement, low power consumption must be preserved for integration in nomadic devices. In this case, it is the tradeoff between performance (e.g., the net throughput on top of the medium access control layer and average power consumption that really matters. It has been shown that adaptive schemes were mandatory to avoid that multiantenna techniques hamper this system tradeoff. In this paper, we derive smartMIMO: an adaptive multiantenna approach which, next to simply adapting the modulation and code rate as traditionally considered, decides packet-per-packet, depending on the MIMO channel state, to use either space-division multiplexing (increasing spectrum efficiency, space-time coding (increasing robustness, or to stick to single-antenna transmission. Contrarily to many of such adaptive schemes, the focus is set on using multiantenna transmission to improve the link energy efficiency in real operation conditions. Based on a model calibrated on an existing reconfigurable multiantenna transceiver setup, the link energy efficiency with the proposed scheme is shown to be improved by up to 30% when compared to nonadaptive schemes. The average throughput is, on the other hand, improved by up to 50% when compared to single-antenna transmission.

  8. Patient positioning based on a radioactive tracer implanted in patients with localized prostate cancer: a performance and safety evaluation.

    Science.gov (United States)

    de Kruijf, Willy J M; Verstraete, Jan; Neustadter, David; Corn, Benjamin W; Hol, Sandra; Venselaar, Jack L M; Davits, Rob J; Wijsman, Bart P; Van den Bergh, Laura; Budiharto, Tom; Oyen, Raymond; Haustermans, Karin; Poortmans, Philip M P

    2013-02-01

    To evaluate the performance and safety of a radiation therapy positioning system (RealEye) based on tracking a radioactive marker (Tracer) implanted in patients with localized prostate cancer. We performed a single-arm multi-institutional trial in 20 patients. The iridium-192 ((192)Ir)-containing Tracer was implanted in the patient together with 4 standard gold seed fiducials. Patient prostate-related symptoms were evaluated with the International Prostate Symptom Score (IPSS) questionnaire. Computed tomography (CT) was performed for treatment planning, during treatment, and after treatment to evaluate the migration stability of the Tracer. At 5 treatment sessions, cone beam CT was performed to test the positioning accuracy of the RealEye. The Tracer was successfully implanted in all patients. No device or procedure-related adverse events occurred. Changes in IPSS scores were limited. The difference between the mean change in Tracer-fiducial distance and the mean change in fiducial-fiducial distance was -0.39 mm (95% confidence interval [CI] upper boundary, -0.22 mm). The adjusted mean difference between Tracer position according to RealEye and the Tracer position on the CBCT for all patients was 1.34 mm (95% CI upper boundary, 1.41 mm). Implantation of the Tracer is feasible and safe. Migration stability of the Tracer is good. Prostate patients can be positioned and monitored accurately by using RealEye. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Localization of Physical Activity in Primary School Children Using Accelerometry and Global Positioning System.

    Directory of Open Access Journals (Sweden)

    Rahel Bürgi

    Full Text Available Ecological approaches have highlighted the importance of the built environment as a factor affecting physical activity. However, knowledge on children's activity patterns is still incomplete. Particularly, data on the spatial context of physical activity is limited, which limits the potential to design location-based interventions effectively. Using global positioning system (GPS and accelerometry, this study aimed to identify locations where children engage in moderate-vigorous physical activity (MVPA.Participants included 119 children (11-14 years, 57% girls from public schools in Winterthur, Switzerland. During a regular school week between February and April 2013, children wore an accelerometer and GPS sensor for seven consecutive days. Time-matched accelerometer and GPS data was mapped with a geographic information system and each data point was assigned to one of seven defined activity settings. Both the absolute amount of MVPA and proportion of time in MVPA were calculated for every setting. Multilevel analyses accounting for the hierarchical structure of the data were conducted to investigate any gender differences.Children achieved most MVPA on streets (34.5% and on school grounds (33.4%. The proportion children spent in MVPA was highest in recreational facilities (19.4%, at other schools (19.2% and on streets (18.6%. Boys accumulated significantly more MVPA overall and on other school grounds (p < 0.05 and showed a significantly higher proportion of time in MVPA at own school and outside of Winterthur (p < 0.05.The results indicate the importance of streets and school grounds as activity-promoting environments. The high use of streets may be an indicator for active transportation, which appears to contribute to an active lifestyle in both genders. In contrast, the school setting is more likely to encourage physical activity in boys. Recreational facilities seem to be conducive for MVPA among both genders, although infrequently visited

  10. Software Defined RF Transceiver for Wireless Sensor Network Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The concept of a smart device capable of communicating and making its own local decisions for wireless sensing, monitoring control, data acquisition, tracking, and...

  11. Software Defined RF Transceiver for Wireless Sensor Network, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The concept of a smart device capable of communicating and making its own local decisions for wireless sensing, monitoring control, data acquisition, tracking, and...

  12. Voice and Video Capacity of a Secure Wireless System

    National Research Council Canada - National Science Library

    Seyba, Jason R

    2007-01-01

    .... The effects of securing the voice signal, real-time traffic originating foreign to a wireless local area network and use of an audio-only signal compared with a combined signal were all studied...

  13. On the Conditional Entropy of Wireless Networks

    DEFF Research Database (Denmark)

    Coon, Justin P.; Badiu, Mihai Alin; Gündüz, Deniz

    2018-01-01

    The characterization of topological uncertainty in wireless networks using the formalism of graph entropy has received interest in the spatial networks community. In this paper, we develop lower bounds on the entropy of a wireless network by conditioning on potential network observables. Two...... approaches are considered: 1) conditioning on subgraphs, and 2) conditioning on node positions. The first approach is shown to yield a relatively tight bound on the network entropy. The second yields a loose bound, in general, but it provides insight into the dependence between node positions (modelled using...

  14. The theories and key technologies for the new generation mine wireless information system

    Energy Technology Data Exchange (ETDEWEB)

    Yang, W.; Feng, X.; Cheng, S.; Sun, J. [Beijing Jiaotong University, Beijing (China). Key Laboratory of ARP Optical Network and Advanced Telecommunication Network

    2004-07-01

    Breaking through the traditional mine wireless communication theories and technologies, combining advanced wireless communication technologies, wireless network technologies with optical fiber communication technologies have been proposed to construct a new generation mine wireless information system. This has a full range of functions such as managing mobile communications, vehicle positioning and navigation, personnel positioning and tracing, wireless multimedia surveillance, mobile computing and mine environment parameters monitoring. The relevant theories and key technologies were proposed. The urgency to do research work for China is stressed. 10 refs., 2 figs.

  15. Wireless mobile Internet security

    CERN Document Server

    Rhee, Man Young

    2013-01-01

      The mobile industry for wireless cellular services has grown at a rapid pace over the past decade. Similarly, Internet service technology has also made dramatic growth through the World Wide Web with a wire line infrastructure. Realization for complete wired/wireless mobile Internet technologies will become the future objectives for convergence of these technologies thr

  16. Radio/Antenna Mounting System for Wireless Networking under Row-Crop Agriculture Conditions

    Directory of Open Access Journals (Sweden)

    Daniel K. Fisher

    2015-07-01

    Full Text Available Interest in and deployment of wireless monitoring systems is increasing in many diverse environments, including row-crop agricultural fields. While many studies have been undertaken to evaluate various aspects of wireless monitoring and networking, such as electronic hardware components, data-collection procedures, power management, and communication protocols, little information related to physical deployment issues has been reported. To achieve acceptable wireless transmission capability, the radio/antenna must be positioned properly relative to the ground surface or crop canopy to minimize degradation of the radio signal, usually requiring the mounting of the radio/antenna above the canopy. This results in the presence of obstacles to normal agricultural equipment traffic and production operations and potential damage to the wireless monitoring system. A simple and rugged radio/antenna mounting system was designed which could be subjected to encounters with agricultural equipment without suffering physical damage. The mounting system was deployed and tested, and operated successfully following repeated encounters with various agricultural machines and implements. The radio/antenna mount is simple and inexpensive to fabricate using locally available components.

  17. Effects of core position of locally resonant scatterers on low-frequency acoustic absorption in viscoelastic panel

    International Nuclear Information System (INIS)

    Zhong Jie; Wen Ji-Hong; Zhao Hong-Gang; Yin Jian-Fei; Yang Hai-Bin

    2015-01-01

    Locally resonant sonic materials, due to their ability to control the propagation of low-frequency elastic waves, have become a promising option for underwater sound absorption materials. In this paper, the finite element method is used to investigate the absorption characteristics of a viscoelastic panel periodically embedded with a type of infinite-long non-coaxially cylindrical locally resonant scatterers (LRSs). The effect of the core position in the coating layer of the LRS on the low-frequency (500 Hz–3000 Hz) sound absorption property is investigated. With increasing the longitudinal core eccentricity e, there occur few changes in the absorptance at the frequencies below 1500 Hz, however, the absorptance above 1500 Hz becomes gradually better and the valid absorption (with absorptance above 0.8) frequency band (VAFB) of the viscoelastic panel becomes accordingly broader. The absorption mechanism is revealed by using the displacement field maps of the viscoelastic panel and the steel slab. The results show two typical resonance modes. One is the overall resonance mode (ORM) caused by steel backing, and the other is the core resonance mode (CRM) caused by LRS. The absorptance of the viscoelastic panel by ORM is induced mainly by the vibration of the steel slab and affected little by core position. On the contrary, with increasing the core eccentricity, the CRM shifts toward high frequency band and decouples with the ORM, leading to two separate absorption peaks and the broadened VAFB of the panel. (paper)

  18. Wireless capsule endo bronchoscopy

    Directory of Open Access Journals (Sweden)

    Baratz DM

    2014-03-01

    Full Text Available No abstract available. Article truncated at 150 words. Case Presentation History of Present Illness A 67 year-old man presents 10 days after swallowing a capsule endoscopy camera that was never retrieved. The wireless capsule was swallowed asymptomatically for evaluation of heme positive stools after negative upper and lower endoscopies. Patient noted that the evening after swallowing the camera he developed mild shortness of breath and cough. The cough and shortness of breath were persistent and worsened while lying down and when moving positions. He denied prior issues with swallowing or aspiration. Review of Systems Negative other than what is noted above. PMH, SH, and FH Past medical history: coronary artery disease, peripheral vascular disease, hyperlipidemia Surgical history: femoral-popliteal bypass, previous shoulder and back surgery Social history: 1 pack/day of cigarettes for 50 years, prior alcohol usage but not current, no illicit drugs Family history: no pulmonary diseases Physical Exam Vital signs: temperature 36.7º C, heart rate 86 beats per minute ...

  19. Security for multihop wireless networks

    CERN Document Server

    Khan, Shafiullah

    2014-01-01

    Security for Multihop Wireless Networks provides broad coverage of the security issues facing multihop wireless networks. Presenting the work of a different group of expert contributors in each chapter, it explores security in mobile ad hoc networks, wireless sensor networks, wireless mesh networks, and personal area networks.Detailing technologies and processes that can help you secure your wireless networks, the book covers cryptographic coprocessors, encryption, authentication, key management, attacks and countermeasures, secure routing, secure medium access control, intrusion detection, ep

  20. Localization of preferential sites of rearrangement within the BCR gene in Philadelphia chromosome-positive acute lymphoblastic leukemia

    International Nuclear Information System (INIS)

    Denny, C.T.; Shah, N.P.; Ogden, S.; Willman, C.; McConnell, T.; Crist, W.; Carroll, A.; Witte, O.N.

    1989-01-01

    The Philadelphia chromosome associated with acute lymphoblastic leukemia (ALL) has been linked to a hybrid BCR/ABL protein product that differs from that found in chronic myelogenous leukemia. This implies that the molecular structures of the two chromosomal translocations also differ. Localization of translocation breakpoints in Philadelphia chromosome-positive ALL has been impeded due to the only partial characterization of the BCR locus. The authors have isolated the entire 130-kilobase BCR genomic locus from a human cosmid library. They have demonstrated that these breakpoints are all located at the 3' end of the intron around an unusual restriction fragment length polymorphism caused by deletion of a 1-kilobase fragment containing Alu family reiterated sequences. This clustering is unexpected in light of previous theories of rearrangement in Philadelphia chromosome-positive chronic myelogenous leukemia that would have predicted a random dispersion of breakpoints in the first intron in Philadelphia chromosome-positive ALL. The proximity of the translocation breakpoints to this constitutive deletion may indicate shared mechanisms of rearrangement or that such polymorphisms mark areas of the genome prone to recombination

  1. The wireless internet explained

    CERN Document Server

    Rhoton, John

    2001-01-01

    The Wireless Internet Explained covers the full spectrum of wireless technologies from a wide range of vendors, including initiatives by Microsoft and Compaq. The Wireless Internet Explained takes a practical look at wireless technology. Rhoton explains the concepts behind the physics, and provides an overview that clarifies the convoluted set of standards heaped together under the umbrella of wireless. It then expands on these technical foundations to give a panorama of the increasingly crowded landscape of wireless product offerings. When it comes to actual implementation the book gives abundant down-to-earth advice on topics ranging from the selection and deployment of mobile devices to the extremely sensitive subject of security.Written by an expert on Internet messaging, the author of Digital Press''s successful Programmer''s Guide to Internet Mail and X.400 and SMTP: Battle of the E-mail Protocols, The Wireless Internet Explained describes and evaluates the current state of the fast-growing and crucial...

  2. Nonlinear Optimization-Based Device-Free Localization with Outlier Link Rejection

    Directory of Open Access Journals (Sweden)

    Wendong Xiao

    2015-04-01

    Full Text Available Device-free localization (DFL is an emerging wireless technique for estimating the location of target that does not have any attached electronic device. It has found extensive use in Smart City applications such as healthcare at home and hospitals, location-based services at smart spaces, city emergency response and infrastructure security. In DFL, wireless devices are used as sensors that can sense the target by transmitting and receiving wireless signals collaboratively. Many DFL systems are implemented based on received signal strength (RSS measurements and the location of the target is estimated by detecting the changes of the RSS measurements of the wireless links. Due to the uncertainty of the wireless channel, certain links may be seriously polluted and result in erroneous detection. In this paper, we propose a novel nonlinear optimization approach with outlier link rejection (NOOLR for RSS-based DFL. It consists of three key strategies, including: (1 affected link identification by differential RSS detection; (2 outlier link rejection via geometrical positional relationship among links; (3 target location estimation by formulating and solving a nonlinear optimization problem. Experimental results demonstrate that NOOLR is robust to the fluctuation of the wireless signals with superior localization accuracy compared with the existing Radio Tomographic Imaging (RTI approach.

  3. Applicable approach of the wireless technology for Korean nuclear power plants

    International Nuclear Information System (INIS)

    Ko, Do Young; Lee, Soo Ill

    2013-01-01

    Highlights: • To apply wireless technology for Korean NPPs, several stipulations are proposed. • WLAN is proposed as the most appropriate wireless technology for Korean NPPs. • WLAN can be applied to the specific fields except in the control system. • An attitude survey on wireless showed that 94.7% agree with the necessity of wireless. - Abstract: Recently, many nuclear power plants (NPPs) over the world use various types of wireless systems for the advantages. Unfortunately, wireless technologies are not currently installed in any Korean NPPs because it is difficult to solve the negative impact of unexpected outcomes or failures from the influence of the wireless technologies, which is electromagnetic interference and radio-frequency interference (EMI/RFI). Moreover, a lack of desire on the part of Korean nuclear industry to implement it leads to give up benefit from the wireless technologies. To install the wireless technologies with maximum benefit and minimum risk, a systematic approach, which quantify the negative impact and prevent the influence, is essential; therefore, this paper describes an applicable research result on the wireless technology for Korean NPPs based on regulatory guides and current wireless hardware and software technologies. Also, survey on the needs for the wireless technology for Korean nuclear power plants was conducted, because the level of awareness of workers in NPPs regarding wireless technologies is very important issue. In this paper, we propose an applicable system to enhance the applicability for the wireless technology for Korean NPPs. The result based on proposed applicable system shows that wireless local area network (WLAN) is the representative candidate for Korean NPPs, which can be applied to the specific fields of radiation monitoring, voice and data communication, component monitoring and instrumentation, and wireless cameras

  4. Wireless rechargeable sensor networks

    CERN Document Server

    Yang, Yuanyuan

    2015-01-01

    This SpringerBrief provides a concise guide to applying wireless energy transfer techniques in traditional battery-powered sensor networks. It examines the benefits and challenges of wireless power including efficiency and reliability. The authors build a wireless rechargeable sensor networks from scratch and aim to provide perpetual network operation. Chapters cover a wide range of topics from the collection of energy information and recharge scheduling to joint design with typical sensing applications such as data gathering. Problems are approached using a natural combination of probability

  5. Wireless network pricing

    CERN Document Server

    Huang, Jianwei

    2013-01-01

    Today's wireless communications and networking practices are tightly coupled with economic considerations, to the extent that it is almost impossible to make a sound technology choice without understanding the corresponding economic implications. This book aims at providing a foundational introduction on how microeconomics, and pricing theory in particular, can help us to understand and build better wireless networks. The book can be used as lecture notes for a course in the field of network economics, or a reference book for wireless engineers and applied economists to understand how pricing

  6. Wireless mesh networks

    CERN Document Server

    Held, Gilbert

    2005-01-01

    Wireless mesh networking is a new technology that has the potential to revolutionize how we access the Internet and communicate with co-workers and friends. Wireless Mesh Networks examines the concept and explores its advantages over existing technologies. This book explores existing and future applications, and examines how some of the networking protocols operate.The text offers a detailed analysis of the significant problems affecting wireless mesh networking, including network scale issues, security, and radio frequency interference, and suggests actual and potential solutions for each pro

  7. Optical and wireless technologies

    CERN Document Server

    Tiwari, Manish; Singh, Ghanshyam; Minzioni, Paolo

    2018-01-01

    This book presents selected papers from 1st International Conference on Optical and Wireless Technologies, providing insights into the analytical, experimental, and developmental aspects of systems, techniques, and devices in these spheres. It explores the combined use of various optical and wireless technologies in next-generation networking applications, and discusses the latest developments in applications such as photonics, high-speed communication systems and networks, visible light communication, nanophotonics, and wireless and multiple-input-multiple-output (MIMO) systems. The book will serve as a valuable reference resource for academics and researchers across the globe.

  8. Validity of the Catapult ClearSky T6 Local Positioning System for Team Sports Specific Drills, in Indoor Conditions

    Directory of Open Access Journals (Sweden)

    Live S. Luteberget

    2018-04-01

    Full Text Available Aim: The aim of the present study was to determine the validity of position, distance traveled and instantaneous speed of team sport players as measured by a commercially available local positioning system (LPS during indoor use. In addition, the study investigated how the placement of the field of play relative to the anchor nodes and walls of the building affected the validity of the system.Method: The LPS (Catapult ClearSky T6, Catapult Sports, Australia and the reference system [Qualisys Oqus, Qualisys AB, Sweden, (infra-red camera system] were installed around the field of play to capture the athletes' motion. Athletes completed five tasks, all designed to imitate team-sports movements. The same protocol was completed in two sessions, one with an assumed optimal geometrical setup of the LPS (optimal condition, and once with a sub-optimal geometrical setup of the LPS (sub-optimal condition. Raw two-dimensional position data were extracted from both the LPS and the reference system for accuracy assessment. Position, distance and speed were compared.Results: The mean difference between the LPS and reference system for all position estimations was 0.21 ± 0.13 m (n = 30,166 in the optimal setup, and 1.79 ± 7.61 m (n = 22,799 in the sub-optimal setup. The average difference in distance was below 2% for all tasks in the optimal condition, while it was below 30% in the sub-optimal condition. Instantaneous speed showed the largest differences between the LPS and reference system of all variables, both in the optimal (≥35% and sub-optimal condition (≥74%. The differences between the LPS and reference system in instantaneous speed were speed dependent, showing increased differences with increasing speed.Discussion: Measures of position, distance, and average speed from the LPS show low errors, and can be used confidently in time-motion analyses for indoor team sports. The calculation of instantaneous speed from LPS raw data is not valid. To

  9. Both antiviral activity and intracellular localization of chicken Mx protein depend on a polymorphism at amino acid position 631.

    Science.gov (United States)

    Sasaki, Keisuke; Yoneda, Akihiro; Ninomiya, Akinori; Kawahara, Manabu; Watanabe, Tomomasa

    2013-01-04

    The Mx protein is known to inhibit the multiplication of several RNA viruses. In chickens, a polymorphism at amino acid position 631 (631 aa) of Mx protein has been suggested to be involved in the antiviral ability against vesicular stomatitis virus (VSV) and influenza virus, indicating that a Ser-to-Asn substitution at 631 aa is the source of this antiviral ability. However, how the substitution at 631 aa contributes to the antiviral activity remains to be clarified. In this study, we investigated differences in antiviral activity against VSV and intracellular localization between Ser and Asn types at 631 aa of the chicken Mx protein. The results showed that chicken Mx protein with an Asn at 631 aa inhibited VSV multiplication and Mx distribution in a granular-like pattern in the cytoplasm. However, Mx carrying the Ser type did not inhibit viral growth and homogenous spread throughout the cytoplasm. Furthermore, we found that replacing Ser with Asn at 631 aa provided Mx with antiviral activity against VSV, with Mx showing granular-like distribution in the cytoplasm. These results demonstrated that a single amino acid polymorphism at 631 aa of the chicken Mx protein altered both the antiviral activity and intracellular localization. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. Two-scale cost efficiency optimization of 5G wireless backhaul networks

    OpenAIRE

    Ge, Xiaohu; Tu, Song; Mao, Guoqiang; Lau, Vincent K. N.; Pan, Linghui

    2016-01-01

    To cater for the demands of future fifth generation (5G) ultra-dense small cell networks, the wireless backhaul network is an attractive solution for the urban deployment of 5G wireless networks. Optimization of 5G wireless backhaul networks is a key issue. In this paper we propose a two-scale optimization solution to maximize the cost efficiency of 5G wireless backhaul networks. Specifically, the number and positions of gateways are optimized in the long time scale of 5G wireless backhaul ne...

  11. Wireless Heart Patients and the Quantified Self

    DEFF Research Database (Denmark)

    Grew, Julie Christina; Svendsen, Mette Nordahl

    2017-01-01

    Remote monitoring of implantable cardioverter defibrillator (ICD) patients links patients wirelessly to the clinic via a box in their bedroom. The box transmits data from the ICD to a remote database accessible to clinicians without patient involvement. Data travel across time and space; clinicians...... can monitor patients from a distance and instantly know about cardiac events. Based on ethnographic fieldwork in two Danish hospitals, this article explores the configuration of the wireless ICD patient by following a number of patients through hospitalisation, implantation, in-clinic follow......-up, and remote monitoring. Wireless therapy, we argue, scripts the patient as data. In high-tech clinical encounters, data are enacted as extensions and copies of the patient, and even proxies that, in patients’ experiences, may turn into identity thieves. In illuminating the multiple positions that data take...

  12. Coexistence of malignant phyllodes tumor and her2-positive locally advanced breast cancer in distinct breasts: A case report.

    Science.gov (United States)

    Sato, Tomoi; Muto, Ichiro; Sakai, Takeshi

    2016-01-01

    Phyllodes tumor of the breast is a rare biphasic neoplasm, accounting for less than 1% of all breast tumors. Coexistence of phyllodes tumor and breast cancer in distinct breasts is extremely rare. A 47-year-old Japanese woman presented with bilateral breast lumps. A HER2-positive, unresectable invasive carcinoma in the right breast and fibroadenoma in the left were diagnosed via core needle biopsy. During chemotherapy with anti-HER2 therapy, the breast cancer shrank quickly, while the left breast lump suddenly enlarged. Under a diagnosis of malignant neoplasm of the breast, left mastectomy was performed. Malignant phyllodes tumor was diagnosed by postoperative histological examination and recurred in multiple areas as early as 2 months after surgery. Only 10 cases of coexisting phyllodes tumor and breast cancer in distinct breasts have been reported in the English literature. Phyllodes tumor associated with breast cancer in distinct breasts tends to be malignant. This is the first case of phyllodes tumor rapidly enlarging during anti-HER2 chemotherapy for locally advanced HER2-positive breast cancer. Even during effective treatment of advanced or recurrent breast cancer, attention should also be paid to the contralateral breast for the possible association of a second malignancy such as phyllodes tumor. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Wireless capsule endoscopy

    Science.gov (United States)

    Iddan, Gavriel; Meron, Gavriel; Glukhovsky, Arkady; Swain, Paul

    2000-05-01

    We have developed a new type of endoscopy, which for the first time allows painless endoscopic imaging of the whole of the small bowel. This procedure involves a wireless capsule endoscope and we describe here its successful testing in humans.

  14. Green heterogeneous wireless networks

    CERN Document Server

    Ismail, Muhammad; Nee, Hans-Peter; Qaraqe, Khalid A; Serpedin, Erchin

    2016-01-01

    This book focuses on the emerging research topic "green (energy efficient) wireless networks" which has drawn huge attention recently from both academia and industry. This topic is highly motivated due to important environmental, financial, and quality-of-experience (QoE) considerations. Specifically, the high energy consumption of the wireless networks manifests in approximately 2% of all CO2 emissions worldwide. This book presents the authors’ visions and solutions for deployment of energy efficient (green) heterogeneous wireless communication networks. The book consists of three major parts. The first part provides an introduction to the "green networks" concept, the second part targets the green multi-homing resource allocation problem, and the third chapter presents a novel deployment of device-to-device (D2D) communications and its successful integration in Heterogeneous Networks (HetNets). The book is novel in that it specifically targets green networking in a heterogeneous wireless medium, which re...

  15. mTORC1 Is a Local, Postsynaptic Voltage Sensor Regulated by Positive and Negative Feedback Pathways

    Directory of Open Access Journals (Sweden)

    Farr Niere

    2017-05-01

    Full Text Available The mammalian/mechanistic target of rapamycin complex 1 (mTORC1 serves as a regulator of mRNA translation. Recent studies suggest that mTORC1 may also serve as a local, voltage sensor in the postsynaptic region of neurons. Considering biochemical, bioinformatics and imaging data, we hypothesize that the activity state of mTORC1 dynamically regulates local membrane potential by promoting and repressing protein synthesis of select mRNAs. Our hypothesis suggests that mTORC1 uses positive and negative feedback pathways, in a branch-specific manner, to maintain neuronal excitability within an optimal range. In some dendritic branches, mTORC1 activity oscillates between the “On” and “Off” states. We define this as negative feedback. In contrast, positive feedback is defined as the pathway that leads to a prolonged depolarized or hyperpolarized resting membrane potential, whereby mTORC1 activity is constitutively on or off, respectively. We propose that inactivation of mTORC1 increases the expression of voltage-gated potassium alpha (Kv1.1 and 1.2 and beta (Kvβ2 subunits, ensuring that the membrane resets to its resting membrane potential after experiencing increased synaptic activity. In turn, reduced mTORC1 activity increases the protein expression of syntaxin-1A and promotes the surface expression of the ionotropic glutamate receptor N-methyl-D-aspartate (NMDA-type subunit 1 (GluN1 that facilitates increased calcium entry to turn mTORC1 back on. Under conditions such as learning and memory, mTORC1 activity is required to be high for longer periods of time. Thus, the arm of the pathway that promotes syntaxin-1A and Kv1 protein synthesis will be repressed. Moreover, dendritic branches that have low mTORC1 activity with increased Kv expression would balance dendrites with constitutively high mTORC1 activity, allowing for the neuron to maintain its overall activity level within an ideal operating range. Finally, such a model suggests that

  16. Is referring patients with a positive history of allergic drug reactions or atopy for allergy testing to local anesthetics justified?

    Science.gov (United States)

    Erdeljic, Viktorija; Francetic, Igor; Likic, Robert; Bakran, Ivan; Makar-Ausperger, Ksenija; Simic, Petra

    2009-04-01

    Although no more than 1% of adverse reactions to local anesthetics (LA) are thought to be immunologically mediated, many patients continue to be referred to allergy clinics for allergy workup. We evaluated the impact of a history of drug hypersensitivity or atopy on results of allergy testing to LA, with the aim of determining the appropriateness of allergy testing to LA in such patients. We retrospectively analyzed medical records of 112 consecutive patients referred for allergy testing to LA in a 9-year period (1996-2005). Intradermal tests with diluted (1:10) LA were performed to identify patients at risk for immunoglobulin E (IgE)-mediated hypersensitivity reaction. The odds for being testpositive were calculated with regard to the defined risk factors (atopy, history of adverse reactions to LA or other drugs, underlying autoimmune disease). Eleven of 112 patients (9.8%) tested positive for allergy to LA. Atopy, history of adverse reactions to LA or other drugs and underlying autoimmune disease did not increase the odds for being test-positive. The prevalence of multiple drug hypersensitivity, IgE values and eosinophil count were not significantly higher among the patients who tested positive as compared to the patients who tested negative. According to our data, allergy testing to LA is not justified in patients with atopy or histories of adverse drug reactions other than to LA. Further studies using validated methods of allergy testing to LA coupled with analysis of defined risk factors are needed to definitively establish the indications for referral of patients for allergy testing to LA. Copyright 2009 Prous Science, S.A.U. or its licensors. All rights reserved.

  17. Wireless radio a history

    CERN Document Server

    Coe, Lewis

    2006-01-01

    ""Informative...recommended""--Choice; ""interesting...a good read...well worth reading""--Contact Magazine. This history first looks at Marconi's wireless communications system and then explores its many applications, including marine radio, cellular telephones, police and military uses, television and radar. Radio collecting is also discussed, and brief biographies are provided for the major figures in the development and use of the wireless.

  18. Wireless Networks Security

    OpenAIRE

    Jenko, Marko

    2016-01-01

    In this thesis we deal with security, penetration testing and different types of attacks on wireless networks. We theoretically familiarize with the field of wireless networks, security mechanisms and the most used security standards. Then we systematically overview the field of penetration testing. We divide the penetration testing on types and different methodologies. We explain the tasks of the provider and the subscriber in penetration testing. Description of the process of conducting the...

  19. Linux-Based Access Point Dalam Wireless LAN

    OpenAIRE

    Witono, Timotius

    2006-01-01

    Technology 802.11 which more known as WiFi, have started to become the cablereplacement technology especially in local network so-called Wireless LAN. Mostly Wireless LAN use the Infrastructure topology, which require uses of one or more Access Points as the communication center of Mobile Stations. Existence of a high quality Access Point is an important factor to determine the quality of Wireless LAN performance. Besides using Access Point that made in factory, Access Point can be custom-bui...

  20. Convergence of wireless, wireline, and photonics next generation networks

    CERN Document Server

    Iniewski, Krzysztof

    2010-01-01

    Filled with illustrations and practical examples from industry, this book provides a brief but comprehensive introduction to the next-generation wireless networks that will soon replace more traditional wired technologies. Written by a mixture of top industrial experts and key academic professors, it is the only book available that covers both wireless networks (such as wireless local area and personal area networks) and optical networks (such as long-haul and metropolitan networks) in one volume. It gives engineers and engineering students the necessary knowledge to meet challenges of next-ge

  1. An Energy-Efficient Link Layer Protocol for Reliable Transmission over Wireless Networks

    Directory of Open Access Journals (Sweden)

    Iqbal Adnan

    2009-01-01

    Full Text Available In multihop wireless networks, hop-by-hop reliability is generally achieved through positive acknowledgments at the MAC layer. However, positive acknowledgments introduce significant energy inefficiencies on battery-constrained devices. This inefficiency becomes particularly significant on high error rate channels. We propose to reduce the energy consumption during retransmissions using a novel protocol that localizes bit-errors at the MAC layer. The proposed protocol, referred to as Selective Retransmission using Virtual Fragmentation (SRVF, requires simple modifications to the positive-ACK-based reliability mechanism but provides substantial improvements in energy efficiency. The main premise of the protocol is to localize bit-errors by performing partial checksums on disjoint parts or virtual fragments of a packet. In case of error, only the corrupted virtual fragments are retransmitted. We develop stochastic models of the Simple Positive-ACK-based reliability, the previously-proposed Packet Length Optimization (PLO protocol, and the SRVF protocol operating over an arbitrary-order Markov wireless channel. Our analytical models show that SRVF provides significant theoretical improvements in energy efficiency over existing protocols. We then use bit-error traces collected over different real networks to empirically compare the proposed and existing protocols. These experimental results further substantiate that SRVF provides considerably better energy efficiency than Simple Positive-ACK and Packet Length Optimization protocols.

  2. Anticipating WPS PIN Vulnerability to Secure Wireless Network

    Directory of Open Access Journals (Sweden)

    Indra Dwi Rianto

    2013-12-01

    Full Text Available WiFi Protected Setup (WPS is a standardized function supported by numerous vendors of wireless routers and access point to help set up connection to a wireless local area network. It is designed to simplify the set up and generally enabled by default. Due to design flaw, the WPS or QSS PIN is susceptible to a brute forceattack. In this paper, we test the security vulnerability occurred, evaluate the performance and give recommendations to anticipate the attack.

  3. Nuclear localization and cytosolic overexpression of LASP-1 correlates with tumor size and nodal-positivity of human breast carcinoma

    International Nuclear Information System (INIS)

    Grunewald, Thomas GP; Kammerer, Ulrike; Kapp, Michaela; Eck, Matthias; Dietl, Johannes; Butt, Elke; Honig, Arnd

    2007-01-01

    LIM and SH3 protein 1 (LASP-1), initially identified from human breast cancer, is a specific focal adhesion protein involved in cell proliferation and migration, which was reported to be overexpressed in 8–12 % of human breast cancers and thought to be exclusively located in cytoplasm. In the present work we analyzed the cellular and histological expression pattern of LASP-1 and its involvement in biological behavior of human breast cancer through correlation with standard clinicopathological parameters and expression of c-erbB2 (HER-2/neu), estrogen- (ER) and progesterone-receptors (PR). For this purpose immunohistochemical staining intensity and percentage of stained cells were semi-quantitatively rated to define a LASP-1 immunoreactive score (LASP-1-IRS). LASP-1-IRS was determined in 83 cases of invasive ductal breast carcinomas, 25 ductal carcinomas in situ (DCIS) and 18 fibroadenomas. Cellular LASP-1 distribution and expression pattern was visualized by immunofluorescence and confocal microscopy and assessed through separate Western blots of nuclear and cytosol preparations of BT-20, MCF-7, MDA-MB231, and ZR-75/1 breast cancer cells. Statistical analysis revealed that the resulting LASP-1-IRS was significantly higher in invasive carcinomas compared to fibroadenomas (p = 0.0176). Strong cytoplasmatic expression of LASP-1 was detected in 55.4 % of the invasive carcinomas, which correlated significantly with nuclear LASP-1-positivity (p = 0.0014), increased tumor size (p = 0.0159) and rate of nodal-positivity (p = 0.0066). However, levels of LASP-1 expression did not correlate with average age at time point of diagnosis, histological tumor grading, c-erbB2-, ER- or PR-expression. Increased nuclear localization and cytosolic expression of LASP-1 was found in breast cancer with higher tumor stage as well as in rapidly proliferating epidermal basal cells. Confocal microscopy and separate Western blots of cytosolic and nuclear preparations confirmed nuclear

  4. Characterization of a GM7 glioblastoma cell line showing CD133 positivity and both cytoplasmic and nuclear localization of nestin.

    Science.gov (United States)

    Loja, Tomas; Chlapek, Petr; Kuglik, Petr; Pesakova, Martina; Oltova, Alexandra; Cejpek, Pavel; Veselska, Renata

    2009-01-01

    A newly established GM7 cell line was derived from the tumor tissue of a 65-year-old man surgically treated for a relapse of glioblastoma multiforme that occurred 10 months after first surgery following radiotherapy. GM7 cells exhibit spindle or glia-like morphology, and multinucleated giant cells are also present in the culture. The cells proliferate rapidly (PDT is about 18 h) and tend to grow in multilayer without contact inhibition. Using G-banding and SKY, the GM7 cell line was identified as near-triploid with a large number of structural and numerical abnormalities. Repeated karyotyping during long-term cultivation confirmed a chromosome number of 70+/-3 chromosomes per cell. Special attention was paid to the immunocytochemical analysis of protein markers in this cell line; GM7 cells showed strong positivity for CD133, vimentin, nestin, NF-160 and S-100 protein and weak positivity for GFAP and NSE, but were negative for synaptophysin. The most important features of the GM7 cell line are its stable phenotype CD133+/nestin+, which are accepted as stem cell markers in neural stem/progenitor cells, and especially unusual intracellular localization of the IF protein nestin, which was detected and repeatedly confirmed both in the cytoplasm and cell nucleus. For this reason, the new GM7 glioblastoma cell line represents an important model suitable not only for further studies on glioblastoma biology and cancer stem cells, but particularly for the detailed investigation of the role of nestin in transformed cells.

  5. Local SAR in High Pass Birdcage and TEM Body Coils for Multiple Human Body Models in Clinical Landmark Positions at 3T

    Science.gov (United States)

    Yeo, Desmond TB; Wang, Zhangwei; Loew, Wolfgang; Vogel, Mika W; Hancu, Ileana

    2011-01-01

    Purpose To use EM simulations to study the effects of body type, landmark position, and RF body coil type on peak local SAR in 3T MRI. Materials and Methods Numerically computed peak local SAR for four human body models (HBMs) in three landmark positions (head, heart, pelvic) were compared for a high-pass birdcage and a transverse electromagnetic 3T body coil. Local SAR values were normalized to the IEC whole-body average SAR limit of 2.0 W/kg for normal scan mode. Results Local SAR distributions were highly variable. Consistent with previous reports, the peak local SAR values generally occurred in the neck-shoulder area, near rungs, or between tissues of greatly differing electrical properties. The HBM type significantly influenced the peak local SAR, with stockier HBMs, extending extremities towards rungs, displaying the highest SAR. There was also a trend for higher peak SAR in the head-centric and heart-centric positions. The impact of the coil-types studied was not statistically significant. Conclusion The large variability in peak local SAR indicates the need to include more than one HBM or landmark position when evaluating safety of body coils. It is recommended that a HBM with arms near the rungs be included, to create physically realizable high-SAR scenarios. PMID:21509880

  6. Target position uncertainty during visually guided deep-inspiration breath-hold radiotherapy in locally advanced lung cancer

    DEFF Research Database (Denmark)

    Rydhog, Jonas Scherman; de Blanck, Steen Riisgaard; Josipovic, Mirjana

    2017-01-01

    Purpose: The purpose of this study was to estimate the uncertainty in voluntary deep-inspiration breath hold (DISH) radiotherapy for locally advanced non-small cell lung cancer (NSCLC) patients.Methods: Perpendicular fluoroscopic movies were acquired in free breathing (FB) and DIBH during a course...... of visually guided DIBH radiotherapy of nine patients with NSCLC. Patients had liquid markers injected in mediastinal lymph nodes and primary tumours. Excursion, systematic- and random errors, and inter-breath-hold position uncertainty were investigated using an image based tracking algorithm.Results: A mean...... (root-mean-square of the intra-BH SD) during DIBH were 0.5 and 0.3 mm (AP), 0.5 and 0.3 mm (LR), 0.8 and 0.4 mm (CC), respectively. The mean inter-breath-hold shifts were -0.3 mm (AP), -0.2 mm (LR), and -0.2 mm (CC).Conclusion: Intra- and inter-breath-hold uncertainty of tumours and lymph nodes were...

  7. 4G antennas for wireless eyewear devices and related SAR

    Science.gov (United States)

    Cihangir, Aykut; Whittow, Will; Panagamuwa, Chinthana; Jacquemod, Gilles; Gianesello, Frédéric; Luxey, Cyril

    2015-11-01

    In this paper, we first present a feasibility study to design 4G antennas (700-960 MHz and 1.7-2.7 GHz) for eyewear devices. Those eyewear devices should be connected to the last generation cellular networks, Wireless Local Area Networks or wireless hotspots. Three coupling element type antennas with their matching networks are evaluated in terms of reflection coefficient and total radiation efficiency when the eyewear is placed on the user's head. We also present Specific Absorption Rate (SAR) simulations when the eyewear is positioned over a homogeneous SAM phantom and over a heterogeneous VH (Visible Human) phantom: the SAR levels are compared to international limit values. In a second step, we present experimental results obtained with 3D printed eyewear and coupling elements etched on a classical PCB substrate where the matching circuits are optimized close to the feeding point of the coupling element. Simulated and measured values are in very good agreement: 7 to 16% and 9 to 35% total efficiency are respectively obtained for the low- and high-frequency bands. However, simulated SAR values are somewhat higher than authorized levels with preoccupant high electromagnetic field distribution close to the eye of the user.

  8. OPTICAL WIRELESS COMMUNICATION SYSTEM

    Directory of Open Access Journals (Sweden)

    JOSHUA L.Y. CHIENG

    2016-02-01

    Full Text Available The growing demand of bandwidth in this modern internet age has been testing the existing telecommunication infrastructures around the world. With broadband speeds moving towards the region of Gbps and Tbps, many researches have begun on the development of using optical wireless technology as feasible and future methods to the current wireless technology. Unlike the existing radio frequency wireless applications, optical wireless uses electromagnetic spectrums that are unlicensed and free. With that, this project aim to understand and gain better understanding of optical wireless communication system by building an experimental and simulated model. The quality of service and system performance will be investigated and reviewed. This project employs laser diode as the propagation medium and successfully transferred audio signals as far as 15 meters. On its quality of service, results of the project model reveal that the bit error rate increases, signal-to-noise ratio and quality factor decreases as the link distance between the transmitter and receiver increases. OptiSystem was used to build the simulated model and MATLAB was used to assist signal-to-noise ratio calculations. By comparing the simulated and experimental receiver’s power output, the experimental model’s efficiency is at 66.3%. Other than the system’s performance, challenges and factors affecting the system have been investigated and discussed. Such challenges include beam divergence, misalignment and particle absorption.

  9. Coherently Enhanced Wireless Power Transfer

    Science.gov (United States)

    Krasnok, Alex; Baranov, Denis G.; Generalov, Andrey; Li, Sergey; Alù, Andrea

    2018-04-01

    Extraction of electromagnetic energy by an antenna from impinging external radiation is at the basis of wireless communications and wireless power transfer (WPT). The maximum of transferred energy is ensured when the antenna is conjugately matched, i.e., when it is resonant and it has an equal coupling with free space and its load. This condition, however, can be easily affected by changes in the environment, preventing optimal operation of a WPT system. Here, we introduce the concept of coherently enhanced WPT that allows us to bypass this difficulty and achieve dynamic control of power transfer. The approach relies on coherent excitation of the waveguide connected to the antenna load with a backward propagating signal of specific amplitude and phase. This signal creates a suitable interference pattern at the load resulting in a modification of the local wave impedance, which in turn enables conjugate matching and a largely increased amount of extracted energy. We develop a simple theoretical model describing this concept, demonstrate it with full-wave numerical simulations for the canonical example of a dipole antenna, and verify experimentally in both near-field and far-field regimes.

  10. Reactor building indoor wireless network channel quality estimation using RSSI measurement of wireless sensor network

    International Nuclear Information System (INIS)

    Merat, S.

    2008-01-01

    Expanding wireless communication network reception inside reactor buildings (RB) and service wings (SW) has always been a technical challenge for operations service team. This is driven by the volume of metal equipment inside the Reactor Buildings (RB) that blocks and somehow shields the signal throughout the link. In this study, to improve wireless reception inside the Reactor Building (RB), an experimental model using indoor localization mesh based on IEEE 802.15 is developed to implement a wireless sensor network. This experimental model estimates the distance between different nodes by measuring the RSSI (Received Signal Strength Indicator). Then by using triangulation and RSSI measurement, the validity of the estimation techniques is verified to simulate the physical environmental obstacles, which block the signal transmission. (author)

  11. EXPERIMENTAL PERFORMANCE ANALYSIS OF WIRELESS ...

    African Journals Online (AJOL)

    ABSTRACT. Wireless networking is currently being deployed for various applications. However, the application of wireless networking in healthcare remains a challenge mainly because of security and reliability concerns. This paper presents experimental results of performance analysis of a wireless network for healthcare ...

  12. Wireless LAN security management with location detection capability in hospitals.

    Science.gov (United States)

    Tanaka, K; Atarashi, H; Yamaguchi, I; Watanabe, H; Yamamoto, R; Ohe, K

    2012-01-01

    In medical institutions, unauthorized access points and terminals obstruct the stable operation of a large-scale wireless local area network (LAN) system. By establishing a real-time monitoring method to detect such unauthorized wireless devices, we can improve the efficiency of security management. We detected unauthorized wireless devices by using a centralized wireless LAN system and a location detection system at 370 access points at the University of Tokyo Hospital. By storing the detected radio signal strength and location information in a database, we evaluated the risk level from the detection history. We also evaluated the location detection performance in our hospital ward using Wi-Fi tags. The presence of electric waves outside the hospital and those emitted from portable game machines with wireless communication capability was confirmed from the detection result. The location detection performance showed an error margin of approximately 4 m in detection accuracy and approximately 5% in false detection. Therefore, it was effective to consider the radio signal strength as both an index of likelihood at the detection location and an index for the level of risk. We determined the location of wireless devices with high accuracy by filtering the detection results on the basis of radio signal strength and detection history. Results of this study showed that it would be effective to use the developed location database containing radio signal strength and detection history for security management of wireless LAN systems and more general-purpose location detection applications.

  13. Wireless networking for the dental office: current wireless standards and security protocols.

    Science.gov (United States)

    Mupparapu, Muralidhar; Arora, Sarika

    2004-11-15

    Digital radiography has gained immense popularity in dentistry today in spite of the early difficulty for the profession to embrace the technology. The transition from film to digital has been happening at a faster pace in the fields of Orthodontics, Oral Surgery, Endodontics, Periodontics, and other specialties where the radiographic images (periapical, bitewing, panoramic, cephalometric, and skull radiographs) are being acquired digitally, stored within a server locally, and eventually accessed for diagnostic purposes, along with the rest of the patient data via the patient management software (PMS). A review of the literature shows the diagnostic performance of digital radiography is at least comparable to or even better than that of conventional radiography. Similarly, other digital diagnostic tools like caries detectors, cephalometric analysis software, and digital scanners were used for many years for the diagnosis and treatment planning purposes. The introduction of wireless charged-coupled device (CCD) sensors in early 2004 (Schick Technologies, Long Island City, NY) has moved digital radiography a step further into the wireless era. As with any emerging technology, there are concerns that should be looked into before adapting to the wireless environment. Foremost is the network security involved in the installation and usage of these wireless networks. This article deals with the existing standards and choices in wireless technologies that are available for implementation within a contemporary dental office. The network security protocols that protect the patient data and boost the efficiency of modern day dental clinics are enumerated.

  14. Favorable outcomes in locally advanced and node positive prostate cancer patients treated with combined pelvic IMRT and androgen deprivation therapy

    International Nuclear Information System (INIS)

    Lilleby, Wolfgang; Narrang, Amol; Tafjord, Gunnar; Vlatkovic, Ljiljana; Russnes, Kjell Magne; Stensvold, Andreas; Hole, Knut Håkon; Tran, Phuoc; Eilertsen, Karsten

    2015-01-01

    The most appropriate treatment for men with prostate cancer and positive pelvic nodes, N+, is an area of active controversy. We report our 5-years outcomes in men with locally advanced prostate cancer (T1-T4N0-N1M0) treated with definitive radiotherapy encompassing the prostate and pelvic lymph nodes (intensity modulated radiotherapy, IMRT) and long-term androgen deprivation therapy (ADT). Of the 138 consecutive eligible men all living patients have been followed up to almost 5 years. Survival endpoints for 5-year biochemical failure-free survival (BFFS), relapse-free survival (RFS), prostate cancer-specific survival (PCSS), and overall survival (OS) were assessed by Kaplan-Meier analysis. Univariate and multivariate Cox regression proportional hazards models were constructed for all survival endpoints. The RTOG morbidity grading system for physician rated toxicity was applied. Patients with locally advanced T3-T4 tumors (35 %) and N1 (51 %) have favorable outcome when long-term ADT is combined with definitive radiotherapy encompassing pelvic lymph nodes. The 5-year BFFS, RFS, PCSS and OS were 71.4, 76.2, 94.5 and 89.0 %, respectively. High Gleason sum (9–10) had a strong independent prognostic impact on BFFS, RFS and OS (p = 0.001, <0.001, and 0.005 respectively). The duration of ADT (= > 28 months) showed a significant independent association with improved PCSS (p = 0.02) and OS (p = 0.001). Lymph node involvement was not associated with survival endpoints in the multivariate analysis. The radiotherapy induced toxicity seen in our study population was moderate with rare Grade 3 GI side effects and up to 11 % for Grade 3 GU consisting mainly of urgency and frequency. Pelvic IMRT in combination with long-term ADT can achieve long-lasting disease control in men with N+ disease and unfavorable prognostic factors. The online version of this article (doi:10.1186/s13014-015-0540-3) contains supplementary material, which is available to authorized users

  15. Optical network unit placement in Fiber-Wireless (FiWi) access network by Moth-Flame optimization algorithm

    Science.gov (United States)

    Singh, Puja; Prakash, Shashi

    2017-07-01

    Hybrid wireless-optical broadband access network (WOBAN) or Fiber-Wireless (FiWi) is the integration of wireless access network and optical network. This hybrid multi-domain network adopts the advantages of wireless and optical domains and serves the demand of technology savvy users. FiWi exhibits the properties of cost effectiveness, robustness, flexibility, high capacity, reliability and is self organized. Optical Network Unit (ONU) placement problem in FiWi contributes in simplifying the network design and enhances the performance in terms of cost efficiency and increased throughput. Several individual-based algorithms, such as Simulated Annealing (SA), Tabu Search, etc. have been suggested for ONU placement, but these algorithms suffer from premature convergence (trapping in a local optima). The present research work undertakes the deployment of FiWi and proposes a novel nature-inspired heuristic paradigm called Moth-Flame optimization (MFO) algorithm for multiple optical network units' placement. MFO is a population based algorithm. Population-based algorithms are better in handling local optima avoidance. The simulation results are compared with the existing Greedy and Simulated Annealing algorithms to optimize the position of ONUs. To the best of our knowledge, MFO algorithm has been used for the first time in this domain, moreover it has been able to provide very promising and competitive results. The performance of MFO algorithm has been analyzed by varying the 'b' parameter. MFO algorithm results in faster convergence than the existing strategies of Greedy and SA and returns a lower value of overall cost function. The results exhibit the dependence of the objective function on the distribution of wireless users also.

  16. Fiber wireless networks

    Science.gov (United States)

    Nirmalathas, A.; Bakaul, M.; Lim, C.; Novak, D.; Waterhouse, R.

    2005-11-01

    Broadband wireless networks based on a number of new frequency windows at higher microwave and millimeter-wave frequencies have been actively pursued to provide ultra-high bandwidth services over a wireless networks. These networks will have a large number of antenna base-stations with high throughput. Significant reductions in antenna base-station complexity can be achieved if most of the signal routing and switching functions centralized at a central office in the network. In such a network, fiber feed networks can be effectively deployed to provide high bandwidth interconnections between multiple antenna base-stations and the central office. With wavelength division multiplexing, efficient optical fiber feed network architectures could be realised to provide interconnection to a large number of antenna base-stations. In this paper, we present an over view of our recent research into system technologies for fiber wireless networks.

  17. Wireless physical layer security

    Science.gov (United States)

    Poor, H. Vincent; Schaefer, Rafael F.

    2017-01-01

    Security in wireless networks has traditionally been considered to be an issue to be addressed separately from the physical radio transmission aspects of wireless systems. However, with the emergence of new networking architectures that are not amenable to traditional methods of secure communication such as data encryption, there has been an increase in interest in the potential of the physical properties of the radio channel itself to provide communications security. Information theory provides a natural framework for the study of this issue, and there has been considerable recent research devoted to using this framework to develop a greater understanding of the fundamental ability of the so-called physical layer to provide security in wireless networks. Moreover, this approach is also suggestive in many cases of coding techniques that can approach fundamental limits in practice and of techniques for other security tasks such as authentication. This paper provides an overview of these developments.

  18. Securing a medical wireless LAN system

    OpenAIRE

    Owens, TJ; Tachakra, S; Banitsas, KA; Istepanian, RSH

    2001-01-01

    Recently the concept of MedLAN systems dedicated to application scenarios for wireless local area networks (WLAN) in hospital A&E departments has been presented. An essential element in the acceptance of the system will be reassuring all stakeholders in the system that data transmitted using the system is secure. In order for the stakeholders to be reassured technical and managerial issues have to be addressed. Technical issues to be addressed include selection of a suitable encryption algori...

  19. Feedback Control of a Hovercraft over a Wireless Link

    Science.gov (United States)

    2006-01-01

    ABSTRACT Title of thesis : FEEDBACK CONTROL OF A HOVERCRAFT OVER A WIRELESS LINK Zachary Kulis, Master of Science, 2006 Dissertation directed by...to agree nicely. FEEDBACK CONTROL OF A HOVERCRAFT OVER A WIRELESS LINK by Zachary Kulis Thesis submitted to the Faculty of the Graduate School of the...stable position and heading tracking control law for a surface vessel. In this thesis , we explore nonlinear control of a hovercraft over a Bluetooth

  20. Lightweight Filter Architecture for Energy Efficient Mobile Vehicle Localization Based on a Distributed Acoustic Sensor Network

    OpenAIRE

    Kim, Keonwook

    2013-01-01

    The generic properties of an acoustic signal provide numerous benefits for localization by applying energy-based methods over a deployed wireless sensor network (WSN). However, the signal generated by a stationary target utilizes a significant amount of bandwidth and power in the system without providing further position information. For vehicle localization, this paper proposes a novel proximity velocity vector estimator (PVVE) node architecture in order to capture the energy from a moving v...

  1. Deformation analysis of the repeated positional surveys in the undermined localities using web applications and WMS map services

    Directory of Open Access Journals (Sweden)

    Milan Talich

    2007-06-01

    Full Text Available The XML web application for on-line calculations of deformation analysis from the repeated positional surveys using Internet service and data is described. Parameters of deformation field (strain tensors, total dilatations are determined in a grid network covering the zone of interest. Displacement vectors from repeated measurements at given points of a geodetic network represent the imput data of calculation. The calculation is based on application of the theory of continuum mechanics and its fundamental prerequisite is homogeneity of the researched territory.The application currently utilizes the Web Map Services - WMS for the graphic presentation of calculated results as GIS. This service for example enables on-line thematic map composition as defined by the user in the window of Internet explorer based on data given by servers of WMS service. Thus the user does not need to own any geographic data to create his/her GIS.Furthermore there are also given application examples of the repeated geodetic surveys used in the field at localities in the forefront of ČSA giant quarry at Komořany and in the undermined territory in Ostrava region. The examples show the independence of calculated values of tensors from rotation and translation of the coordinate systems in practise. This fact gives the evidence that the deformation analysis is more objective dynamic indicator in the researched area and not only the calculus and representation of point displacement vectors. After registration this application is at all interested persons disposal to on-line calculations via the Internet.

  2. Terabit Wireless Communication Challenges

    Science.gov (United States)

    Hwu, Shian U.

    2012-01-01

    This presentation briefly discusses a research effort on Terabit Wireless communication systems for possible space applications. Recently, terahertz (THz) technology (300-3000 GHz frequency) has attracted a great deal of interest from academia and industry. This is due to a number of interesting features of THz waves, including the nearly unlimited bandwidths available, and the non-ionizing radiation nature which does not damage human tissues and DNA with minimum health threat. Also, as millimeter-wave communication systems mature, the focus of research is, naturally, moving to the THz range. Many scientists regard THz as the last great frontier of the electromagnetic spectrum, but finding new applications outside the traditional niches of radio astronomy, Earth and planetary remote sensing, and molecular spectroscopy particularly in biomedical imaging and wireless communications has been relatively slow. Radiologists find this area of study so attractive because t-rays are non-ionizing, which suggests no harm is done to tissue or DNA. They also offer the possibility of performing spectroscopic measurements over a very wide frequency range, and can even capture signatures from liquids and solids. According to Shannon theory, the broad bandwidth of the THz frequency bands can be used for terabit-per-second (Tb/s) wireless communication systems. This enables several new applications, such as cell phones with 360 degrees autostereoscopic displays, optic-fiber replacement, and wireless Tb/s file transferring. Although THz technology could satisfy the demand for an extremely high data rate, a number of technical challenges need to be overcome before its development. This presentation provides an overview the state-of-the- art in THz wireless communication and the technical challenges for an emerging application in Terabit wireless systems. The main issue for THz wave propagation is the high atmospheric attenuation, which is dominated by water vapor absorption in the THz

  3. Wireless communications algorithmic techniques

    CERN Document Server

    Vitetta, Giorgio; Colavolpe, Giulio; Pancaldi, Fabrizio; Martin, Philippa A

    2013-01-01

    This book introduces the theoretical elements at the basis of various classes of algorithms commonly employed in the physical layer (and, in part, in MAC layer) of wireless communications systems. It focuses on single user systems, so ignoring multiple access techniques. Moreover, emphasis is put on single-input single-output (SISO) systems, although some relevant topics about multiple-input multiple-output (MIMO) systems are also illustrated.Comprehensive wireless specific guide to algorithmic techniquesProvides a detailed analysis of channel equalization and channel coding for wi

  4. Pervasive wireless environments

    CERN Document Server

    Yang, Jie; Trappe, Wade; Cheng, Jerry

    2014-01-01

    This Springer Brief provides a new approach to prevent user spoofing by using the physical properties associated with wireless transmissions to detect the presence of user spoofing. The most common method, applying cryptographic authentication, requires additional management and computational power that cannot be deployed consistently. The authors present the new approach by offering a summary of the recent research and exploring the benefits and potential challenges of this method. This brief discusses the feasibility of launching user spoofing attacks and their impact on the wireless and sen

  5. Wireless optical telecommunications

    CERN Document Server

    Bouchet, Olivier

    2013-01-01

    Wireless optical communication refers to communication based on the unguided propagation of optical waves. The past 30 years have seen significant improvements in this technique - a wireless communication solution for the current millennium - that offers an alternative to radio systems; a technique that could gain attractiveness due to recent concerns regarding the potential effects of radiofrequency waves on human health.The aim of this book is to look at the free space optics that are already used for the exchange of current information; its many benefits, such as incorporating chan

  6. Wireless telecommunication systems

    CERN Document Server

    Terré, Michel; Vivier, Emmanuelle

    2013-01-01

    Wireless telecommunication systems generate a huge amount of interest. In the last two decades, these systems have experienced at least three major technological leaps, and it has become impossible to imagine how society was organized without them. In this book, we propose a macroscopic approach on wireless systems, and aim at answering key questions about power, data rates, multiple access, cellular engineering and access networks architectures.We present a series of solved problems, whose objective is to establish the main elements of a global link budget in several radiocommunicati

  7. Distributed topology control algorithm for multihop wireless netoworks

    Science.gov (United States)

    Borbash, S. A.; Jennings, E. H.

    2002-01-01

    We present a network initialization algorithmfor wireless networks with distributed intelligence. Each node (agent) has only local, incomplete knowledge and it must make local decisions to meet a predefined global objective. Our objective is to use power control to establish a topology based onthe relative neighborhood graph which has good overall performance in terms of power usage, low interference, and reliability.

  8. Matching of Energy Provisions in Multihop Wireless Infra-Structures

    Directory of Open Access Journals (Sweden)

    Rui Teng

    2016-01-01

    Full Text Available Recently there have been large advances in energy technologies for battery-operated systems, including green energy resources and high capacity batteries. The effective use of battery energy resources in wireless infrastructure networks to improve the versatility and reliability of wireless communications is an important issue. Emerging applications of smart cities, Internet of Things (IoT, and emergency responses highly rely on the basic communication network infrastructures that enable ubiquitous network connections. However, energy consumption by nodes in a wireless infrastructure network depends on the transmissions of other nodes in the network. Considering this inter-dependence is necessary to achieve efficient provision of energy in wireless networks. This paper studies the issue of energy provision for wireless relay nodes in Wireless Multihop Infrastructures (WMI assuming constraints on the total energy provision. We introduce a scheme of Energy Provision Matching (Matching-EP for WMI which optimizes energy provision based on matching of energy provision with estimates of differentiated position-dependent energy consumption by wireless nodes distributed in the network. The evaluation results show that Matching-EP with 4%–34% improvement in energy matching degree enables 10%–40% improvement of the network lifetime, and 5%–40% improvement of packet delivery compared with conventional WMI networks.

  9. 75 FR 8400 - In the Matter of Certain Wireless Communications System Server Software, Wireless Handheld...

    Science.gov (United States)

    2010-02-24

    ... Communications System Server Software, Wireless Handheld Devices and Battery Packs; Notice of Investigation... within the United States after importation of certain wireless communications system server software... certain wireless communications system server software, wireless handheld devices or battery packs that...

  10. 75 FR 43206 - In the Matter of Certain Wireless Communications System Server Software, Wireless Handheld...

    Science.gov (United States)

    2010-07-23

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-706] In the Matter of Certain Wireless Communications System Server Software, Wireless Handheld Devices and Battery Packs: Notice of Commission... United States after importation of certain wireless communications system server software, wireless...

  11. Multichannel wireless ECoG array ASIC devices.

    Science.gov (United States)

    DeMichele, Glenn A; Cogan, Stuart F; Troyk, Philip R; Chen, Hongnan; Hu, Zhe

    2014-01-01

    Surgical resection of epileptogenic foci is often a beneficial treatment for patients suffering debilitating seizures arising from intractable epilepsy [1], [2], [3]. Electrodes placed subdurally on the surface of the brain in the form of an ECoG array is one of the multiple methods for localizing epileptogenic zones for the purpose of defining the region for surgical resection. Currently, transcutaneous wires from ECoG grids limit the duration of time that implanted grids can be used for diagnosis. A wireless ECoG recording and stimulation system may be a solution to extend the diagnostic period. To avoid the transcutaneous connections, a 64-channel wireless silicon recording/stimulating ASIC was developed as the electronic component of a wireless ECoG array that uses SIROF electrodes on a polyimide substrate[4]. Here we describe two new ASIC devices that have been developed and tested as part of the on-going wireless ECoG system design.

  12. Resource management in wireless networking

    CERN Document Server

    Cardei, Mihaela; Du, Ding-Zhu

    2005-01-01

    This is the first book that provides readers with a deep technical overview of recent advances in resource management for wireless networks at different layers of the protocol stack. The subject is explored in various wireless networks, such as ad hoc wireless networks, 3G/4G cellular, IEEE 802.11, and Bluetooth personal area networks.Survey chapters give an excellent introduction to key topics in resource management for wireless networks, while experts will be satisfied by the technical depth of the knowledge imparted in chapters exploring hot research topics.The subject area discussed in this book is very relevant today, considering the recent remarkable growth of wireless networking and the convergence of wireless personal communications, internet technologies and real-time multimedia.This volume is a very good companion for practitioners working on implementing solutions for multimedia and Quality of Service - sensitive applications over wireless networks.Written for:Researchers, faculty members, students...

  13. Wireless sensor networks principles, design and applications

    CERN Document Server

    Yang, Shuang-Hua

    2014-01-01

    Wireless Sensor Networks presents the latest practical solutions to the design issues presented in wireless-sensor-network-based systems. Novel features of the text, distributed throughout, include workable solutions, demonstration systems and case studies of the design and application of wireless sensor networks (WSNs) based on the first-hand research and development experience of the author, and the chapters on real applications: building fire safety protection; smart home automation; and logistics resource management. Case studies and applications illustrate the practical perspectives of: ·         sensor node design; ·         embedded software design; ·         routing algorithms; ·         sink node positioning; ·         co-existence with other wireless systems; ·         data fusion; ·         security; ·         indoor location tracking; ·         integrating with radio-frequency identification; and ·         In...

  14. Outdoor W-Band Hybrid Photonic Wireless Link Based on an Optical SFP+ Module

    DEFF Research Database (Denmark)

    Rommel, Simon; Rodríguez Páez, Juan Sebastián; Chorchos, Łukasz

    2016-01-01

    This letter proposes aW-band hybrid photonic wireless link based on a commercial SFP+ module and experimentally demonstrates its performance. Using a free running laser as local oscillator and heterodyne photonic upconversion, good frequency stability is achieved. Outdoor wireless transmission over...... 225m with a BER below 10-6 is demonstrated and the maximum reach of the system with typical RF components is calculated, finding wireless distances above 2km to be feasible. Being based on a commercial SFP+ the proposed hybrid photonic wireless link offers seamless integration with existing...

  15. Wireless Distributed Antenna MIMO

    DEFF Research Database (Denmark)

    2015-01-01

    The present disclosure relates to system applications of multicore optical fibers. One embodiment relates to a base transceiver station for a wireless telecommunication system comprising a plurality of antenna units arranged in a MIMO configuration and adapted for transmission and/or reception...

  16. Wireless Remote Control System

    Directory of Open Access Journals (Sweden)

    Adrian Tigauan

    2012-06-01

    Full Text Available This paper presents the design of a wireless remote control system based on the ZigBee communication protocol. Gathering data from sensors or performing control tasks through wireless communication is advantageous in situations in which the use of cables is impractical. An Atmega328 microcontroller (from slave device is used for gathering data from the sensors and transmitting it to a coordinator device with the help of the XBee modules. The ZigBee standard is suitable for low-cost, low-data-rate and low-power wireless networks implementations. The XBee-PRO module, designed to meet ZigBee standards, requires minimal power for reliable data exchange between devices over a distance of up to 1600m outdoors. A key component of the ZigBee protocol is the ability to support networking and this can be used in a wireless remote control system. This system may be employed e.g. to control temperature and humidity (SHT11 sensor and light intensity (TSL230 sensor levels inside a commercial greenhouse.

  17. Subsurface Wireless Sensor Networks

    Science.gov (United States)

    Niemeier, J. J.; Davies, J. L.; Kruger, A.

    2008-12-01

    Conventional thinking holds that underground- and underwater radio communication is not possible, except at very low frequencies employing very long antennas and high transmit power. However, researchers at The University of Iowa have demonstrated that using inexpensive, low-power radios, it is in fact possible to achieve reliable underground radio communication over distances of several meters. This allows for creating underground wireless sensor networks. A proof-of-concept network was established at The University of Iowa, where nodes that measure soil moisture content are buried over a 20×20 m area (up to 1 m deep). The nodes organize themselves into a wireless sensor network, reconfigure routes as radio link quality waxes and wanes, cooperate in routing data packets to a surface base station, and so on. In an agricultural research setting, an advantage of such buried wireless sensor networks is that, if nodes were buried deep enough, they may be left in place during agricultural field work. Power consumption is an important issue in wireless sensor networks. This is especially true in a buried network where battery replacement is a major undertaking. The focus of continuing research is developing methods of inductively recharging buried sensor batteries.

  18. Insecurity of Wireless Networks

    Energy Technology Data Exchange (ETDEWEB)

    Sheldon, Frederick T [ORNL; Weber, John Mark [Dynetics, Inc.; Yoo, Seong-Moo [University of Alabama, Huntsville; Pan, W. David [University of Alabama, Huntsville

    2012-01-01

    Wireless is a powerful core technology enabling our global digital infrastructure. Wi-Fi networks are susceptible to attacks on Wired Equivalency Privacy, Wi-Fi Protected Access (WPA), and WPA2. These attack signatures can be profiled into a system that defends against such attacks on the basis of their inherent characteristics. Wi-Fi is the standard protocol for wireless networks used extensively in US critical infrastructures. Since the Wired Equivalency Privacy (WEP) security protocol was broken, the Wi-Fi Protected Access (WPA) protocol has been considered the secure alternative compatible with hardware developed for WEP. However, in November 2008, researchers developed an attack on WPA, allowing forgery of Address Resolution Protocol (ARP) packets. Subsequent enhancements have enabled ARP poisoning, cryptosystem denial of service, and man-in-the-middle attacks. Open source systems and methods (OSSM) have long been used to secure networks against such attacks. This article reviews OSSMs and the results of experimental attacks on WPA. These experiments re-created current attacks in a laboratory setting, recording both wired and wireless traffic. The article discusses methods of intrusion detection and prevention in the context of cyber physical protection of critical Internet infrastructure. The basis for this research is a specialized (and undoubtedly incomplete) taxonomy of Wi-Fi attacks and their adaptations to existing countermeasures and protocol revisions. Ultimately, this article aims to provide a clearer picture of how and why wireless protection protocols and encryption must achieve a more scientific basis for detecting and preventing such attacks.

  19. Wireless networked music performance

    CERN Document Server

    Gabrielli, Leonardo

    2016-01-01

    This book presents a comprehensive overview of the state of the art in Networked Music Performance (NMP) and a historical survey of computer music networking. It introduces current technical trends in NMP and technical issues yet to be addressed. It also lists wireless communication protocols and compares these to the requirements of NMP. Practical use cases and advancements are also discussed.

  20. 76 FR 11781 - Wireless Telecommunications Bureau Seeks Comment on Petition for Declaratory Ruling Asking To...

    Science.gov (United States)

    2011-03-03

    ...In this document, the Wireless Telecommunications Bureau seeks comment on a December 3, 2010 petition for declaratory ruling (Petition) filed by CTIA-The Wireless Association (Petitioners). The Petitioners ask the Federal Communications Commission (Commission) to clarify ``the scope of Section 332(c)(3)(A)'s ban on state and local entry regulation.''

  1. The Brave New World of Wireless Technologies: A Primer for Educators.

    Science.gov (United States)

    Boerner, Gerald L.

    2002-01-01

    Discusses the use of wireless local area networks (WLANs) on college campuses. Highlights include traditional wired networks; cost, speed, and reliability; wireless networking standards; mobility; installation speed, simplicity, and flexibility; reduced cost of ownership; scalability; security issues; and a glossary of WLAN terms. (LRW)

  2. NASA Bluetooth Wireless Communications

    Science.gov (United States)

    Miller, Robert D.

    2007-01-01

    NASA has been interested in wireless communications for many years, especially when the crew size of the International Space Station (ISS) was reduced to two members. NASA began a study to find ways to improve crew efficiency to make sure the ISS could be maintained with limited crew capacity and still be a valuable research testbed in Low-Earth Orbit (LEO). Currently the ISS audio system requires astronauts to be tethered to the audio system, specifically a device called the Audio Terminal Unit (ATU). Wireless communications would remove the tether and allow astronauts to freely float from experiment to experiment without having to worry about moving and reconnecting the associated cabling or finding the space equivalent of an extension cord. A wireless communication system would also improve safety and reduce system susceptibility to Electromagnetic Interference (EMI). Safety would be improved because a crewmember could quickly escape a fire while maintaining communications with the ground and other crewmembers at any location. In addition, it would allow the crew to overcome the volume limitations of the ISS ATU. This is especially important to the Portable Breathing Apparatus (PBA). The next generation of space vehicles and habitats also demand wireless attention. Orion will carry up to six crewmembers in a relatively small cabin. Yet, wireless could become a driving factor to reduce launch weight and increase habitable volume. Six crewmembers, each tethered to a panel, could result in a wiring mess even in nominal operations. In addition to Orion, research is being conducted to determine if Bluetooth is appropriate for Lunar Habitat applications.

  3. sUAS Position Estimation and Fusion in GPS-Degraded and GPS-Denied Environments using an ADS-B Transponder and Local Area Multilateration

    Science.gov (United States)

    Larson, Robert Sherman

    An Unmanned Aerial Vehicle (UAV) and a manned aircraft are tracked using ADS-B transponders and the Local Area Multilateration System (LAMS) in simulated GPS-degraded and GPS-denied environments. Several position estimation and fusion algorithms are developed for use with the Autonomous Flight Systems Laboratory (AFSL) TRansponder based Position Information System (TRAPIS) software. At the lowest level, these estimation and fusion algorithms use raw information from ADS-B and LAMS data streams to provide aircraft position estimates to the ground station user. At the highest level, aircraft position is estimated using a discrete time Kalman filter with real-time covariance updates and fusion involving weighted averaging of ADS-B and LAMS positions. Simulation and flight test results are provided, demonstrating the feasibility of incorporating an ADS-B transponder on a commercially-available UAS and maintaining situational awareness of aircraft positions in GPS-degraded and GPS-denied environments.

  4. Scalable and Hybrid Radio Resource Management for Future Wireless Networks

    DEFF Research Database (Denmark)

    Mino, E.; Luo, Jijun; Tragos, E.

    2007-01-01

    The concept of ubiquitous and scalable system is applied in the IST WINNER II [1] project to deliver optimum performance for different deployment scenarios, from local area to wide area wireless networks. The integration in a unique radio system of a cellular and local area type networks supposes...... a great advantage for the final user and for the operator, compared with the current situation, with disconnected systems, usually with different subscriptions, radio interfaces and terminals. To be a ubiquitous wireless system, the IST project WINNER II has defined three system modes. This contribution...

  5. Influences of local habitat, tributary position, and dam characteristics on fish assemblages within impoundments of low-head dams in the tributaries of the Qingyi River, China.

    Science.gov (United States)

    Li, Xian; Li, Yu-Ru; Chu, Ling; Zhu, Ren; Wang, Li-Zhu; Yan, Yun-Zhi

    2016-03-18

    Low-head dam impoundments modify local habitat and alter fish assemblages; however, to our knowledge, the pattern of how fish assemblages in the impoundments relate to local habitat, tributary position, and dam characteristics is still unclear. We used data collected in 62 impoundments created by low-head dams in headwater streams of the Qingyi River, China, to examine relationships between fish assemblages and local habitat, tributary position, and dam characteristics. We also assessed the relative importance of the three groups of factors in determining fish species richness and composition. Linear regression models showed that fish species richness was related to substrate heterogeneity, confluence link, and dam number upstream. Redundancy analysis showed that fish species compositions were influenced by substrate heterogeneity, confluence link, dam height, dam numbers upstream and downstream. Overall, dam characteristics were more important in affecting fish species richness but less important in determining fish species composition than local habitat (i.e., substrate heterogeneity) and tributary position. Our results suggest that low-head dam may affect fish species richness in impoundments by modifying local habitat and constraining fish movement, and the relative abundances of those fish species may depend more on species habitat presences and stream size than on impoundment size and number.

  6. A Novel Intelligent Transportation Control Supported by Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Zhe Qian

    2013-05-01

    Full Text Available With the development of wireless sensor unit, and improvement of real-time and quality of wireless communication, the intelligent transportation control system employ these technologies to realize sensing, positioning, computing, and communication for voiding collisions. This paper discusses the framework of transportation control system, and emphases TDOA positioning algorithm and the new weighted least square optimization method. The simulation result shows that, our method achieves high-accuracy of positioning, which can satisfy the need of transportation control. Finally, we outline the urgent work need to address in the future.

  7. Favorable Local Control From Consolidative Radiation Therapy in High-Risk Neuroblastoma Despite Gross Residual Disease, Positive Margins, or Nodal Involvement.

    Science.gov (United States)

    Ferris, Matthew J; Danish, Hasan; Switchenko, Jeffrey M; Deng, Claudia; George, Bradley A; Goldsmith, Kelly C; Wasilewski, Karen J; Cash, W Thomas; Khan, Mohammad K; Eaton, Bree R; Esiashvili, Natia

    2017-03-15

    To report the influence of radiation therapy (RT) dose and surgical pathology variables on disease control and overall survival (OS) in patients treated for high-risk neuroblastoma at a single institution. We conducted a retrospective study of 67 high-risk neuroblastoma patients who received RT as part of definitive management from January 2003 until May 2014. At a median follow-up of 4.5 years, 26 patients (38.8%) failed distantly; 4 of these patients also failed locally. One patient progressed locally without distant failure. Local control was 92.5%, and total disease control was 59.5%. No benefit was demonstrated for RT doses over 21.6 Gy with respect to local relapse-free survival (P=.55), disease-free survival (P=.22), or OS (P=.72). With respect to local relapse-free survival, disease-free survival, and OS, no disadvantage was seen for positive lymph nodes on surgical pathology, positive surgical margins, or gross residual disease. Of the patients with gross residual disease, 75% (6 of 8) went on to have no evidence of disease at time of last follow-up, and the 2 patients who failed did so distantly. Patients with high-risk neuroblastoma in this series maintained excellent local control, with no benefit demonstrated for radiation doses over 21.6 Gy, and no disadvantage demonstrated for gross residual disease after surgery, positive surgical margins, or pathologic lymph node positivity. Though the limitations of a retrospective review for an uncommon disease must be kept in mind, with small numbers in some of the subgroups, it seems that dose escalation should be considered only in exceptional circumstances. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Favorable Local Control From Consolidative Radiation Therapy in High-Risk Neuroblastoma Despite Gross Residual Disease, Positive Margins, or Nodal Involvement

    Energy Technology Data Exchange (ETDEWEB)

    Ferris, Matthew J., E-mail: mjferri@emory.edu [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Danish, Hasan [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Switchenko, Jeffrey M. [Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Department of Biostatistics and Bioinformatics, Emory University, Atlanta, Georgia (United States); Deng, Claudia [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); George, Bradley A.; Goldsmith, Kelly C.; Wasilewski, Karen J.; Cash, W. Thomas [Aflac Cancer and Blood Disorders Center, Children' s Healthcare of Atlanta, Atlanta, Georgia (United States); Khan, Mohammad K.; Eaton, Bree R.; Esiashvili, Natia [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute, Emory University, Atlanta, Georgia (United States)

    2017-03-15

    Purpose: To report the influence of radiation therapy (RT) dose and surgical pathology variables on disease control and overall survival (OS) in patients treated for high-risk neuroblastoma at a single institution. Methods and Materials: We conducted a retrospective study of 67 high-risk neuroblastoma patients who received RT as part of definitive management from January 2003 until May 2014. Results: At a median follow-up of 4.5 years, 26 patients (38.8%) failed distantly; 4 of these patients also failed locally. One patient progressed locally without distant failure. Local control was 92.5%, and total disease control was 59.5%. No benefit was demonstrated for RT doses over 21.6 Gy with respect to local relapse–free survival (P=.55), disease-free survival (P=.22), or OS (P=.72). With respect to local relapse–free survival, disease-free survival, and OS, no disadvantage was seen for positive lymph nodes on surgical pathology, positive surgical margins, or gross residual disease. Of the patients with gross residual disease, 75% (6 of 8) went on to have no evidence of disease at time of last follow-up, and the 2 patients who failed did so distantly. Conclusions: Patients with high-risk neuroblastoma in this series maintained excellent local control, with no benefit demonstrated for radiation doses over 21.6 Gy, and no disadvantage demonstrated for gross residual disease after surgery, positive surgical margins, or pathologic lymph node positivity. Though the limitations of a retrospective review for an uncommon disease must be kept in mind, with small numbers in some of the subgroups, it seems that dose escalation should be considered only in exceptional circumstances.

  9. Investigations of interference between electromagnetic transponders and wireless MOSFET dosimeters: a phantom study.

    Science.gov (United States)

    Su, Zhong; Zhang, Lisha; Ramakrishnan, V; Hagan, Michael; Anscher, Mitchell

    2011-05-01

    To evaluate both the Calypso Systems' (Calypso Medical Technologies, Inc., Seattle, WA) localization accuracy in the presence of wireless metal-oxide-semiconductor field-effect transistor (MOSFET) dosimeters of dose verification system (DVS, Sicel Technologies, Inc., Morrisville, NC) and the dosimeters' reading accuracy in the presence of wireless electromagnetic transponders inside a phantom. A custom-made, solid-water phantom was fabricated with space for transponders and dosimeters. Two inserts were machined with positioning grooves precisely matching the dimensions of the transponders and dosimeters and were arranged in orthogonal and parallel orientations, respectively. To test the transponder localization accuracy with/without presence of dosimeters (hypothesis 1), multivariate analyses were performed on transponder-derived localization data with and without dosimeters at each preset distance to detect statistically significant localization differences between the control and test sets. To test dosimeter dose-reading accuracy with/without presence of transponders (hypothesis 2), an approach of alternating the transponder presence in seven identical fraction dose (100 cGy) deliveries and measurements was implemented. Two-way analysis of variance was performed to examine statistically significant dose-reading differences between the two groups and the different fractions. A relative-dose analysis method was also used to evaluate transponder impact on dose-reading accuracy after dose-fading effect was removed by a second-order polynomial fit. Multivariate analysis indicated that hypothesis 1 was false; there was a statistically significant difference between the localization data from the control and test sets. However, the upper and lower bounds of the 95% confidence intervals of the localized positional differences between the control and test sets were less than 0.1 mm, which was significantly smaller than the minimum clinical localization resolution of 0

  10. Wireless Sensor Network for Indoor Air Quality Monitoring

    Directory of Open Access Journals (Sweden)

    Jun Li

    2014-06-01

    Full Text Available Indoor air quality monitoring system consists of wireless sensor device, nRF24L01 wireless transceiver modules, C8051MCU, STM32103 remote monitoring platform, alarm device and data server. Distributed in the interior space of wireless sensors measure parameters of the local air quality, wireless transceiver module of the MCU to transmit data to the remote monitoring platform for analysis which displayed and stored field environment data or charts. The data collecting from wireless sensors to be send by wireless Access Point to the remote data server based on B/S architecture, intelligent terminals such as mobile phone, laptop, tablet PC on the Internet monitor indoor air quality in real-time. When site environment air quality index data exceeds the threshold in the monitoring device, the remote monitoring platform sends out the alarm SMS signal to inform user by GSM module. Indoor air quality monitoring system uses modular design method, has the portability and scalability has the low manufacture cost, real-time monitoring data and man-machine interaction.

  11. The Lure of Wireless Encryption

    CERN Multimedia

    Computer Security Team

    2013-01-01

    Following our article entitled “Jekyll or Hyde? Better browse securely” in the last issue of the Bulletin, some people wondered why the CERN wireless network is not encrypted…   There are many arguments why it is not. The simplest is usability: the communication and management of the corresponding access keys would be challenging given the sheer number of wireless devices the CERN network hosts. Keys would quickly become public, e.g. at conferences, and might be shared, written on whiteboards, etc. Then there are all the devices which cannot be easily configured to use encryption protocols - a fact which would create plenty of calls to the CERN Service Desk… But our main argument is that wireless encryption is DECEPTIVE. Wireless encryption is deceptive as it only protects the wireless network against unauthorised access (and the CERN network already has other means to protect against that). Wireless encryption however, does not really help you. You ...

  12. Matching theory for wireless networks

    CERN Document Server

    Han, Zhu; Saad, Walid

    2017-01-01

    This book provides the fundamental knowledge of the classical matching theory problems. It builds up the bridge between the matching theory and the 5G wireless communication resource allocation problems. The potentials and challenges of implementing the semi-distributive matching theory framework into the wireless resource allocations are analyzed both theoretically and through implementation examples. Academics, researchers, engineers, and so on, who are interested in efficient distributive wireless resource allocation solutions, will find this book to be an exceptional resource. .

  13. A Wireless Physiological Signal Monitoring System with Integrated Bluetooth and WiFi Technologies.

    Science.gov (United States)

    Yu, Sung-Nien; Cheng, Jen-Chieh

    2005-01-01

    This paper proposes a wireless patient monitoring system which integrates Bluetooth and WiFi wireless technologies. A wireless portable multi-parameter device was designated to acquire physiological signals and transmit them to a local server via Bluetooth wireless technology. Four kinds of monitor units were designed to communicate via the WiFi wireless technology, including a local monitor unit, a control center, mobile devices (personal digital assistant; PDA), and a web page. The use of various monitor units is intending to meet different medical requirements for different medical personnel. This system was demonstrated to promote the mobility and flexibility for both the patients and the medical personnel, which further improves the quality of health care.

  14. Local Immune Homeostasis of Gastric Mucosa in Chronic CagA-positive Hр-associated Gastritis in Children

    Directory of Open Access Journals (Sweden)

    O.Ye. Abaturov

    2012-04-01

    Full Text Available The article deal with study of lymphocyte-macrophage link of the gastric mucosa local immunity in Hр-associated chronic gastritis, taking into account the presence of the cytotoxin-associated gene A (CagA Hр through a standard morphological examination according to the Modified Sydney System and immunohistochemical studies of biopsy specimens.

  15. An Assessment of Emerging Wireless Broadband Technologies

    National Research Council Canada - National Science Library

    Fountanas, Leonidas

    2001-01-01

    ... technologies in providing broadband services today, emerging wireless broadband technologies are expected to significantly increase their market share over the next years, Deploying a wireless network...

  16. Wireless Sensor Portal Technology Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Recognizing the needs and challenges facing NASA Earth Science for data input, manipulation and distribution, Mobitrum is proposing a ? Wireless Sensor Portal...

  17. Adaptive Wireless Transceiver, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Wireless technologies are an increasingly attractive means for spatial data, input, manipulation, and distribution. Mobitrum is proposing an innovative Adaptive...

  18. Smart Home Wireless Sensor Nodes

    DEFF Research Database (Denmark)

    Lynggaard, Per

    Smart homes are further development of intelligent buildings and home automation, where context awareness and autonomous behaviour are added. They are based on a combination of the Internet and emerging technologies like wireless sensor nodes. These wireless sensor nodes are challenging because....... This paper introduces an approach that considerably lowers the wireless sensor node power consumption and the amount of transmitted sensor events. It uses smart objects that include artificial intelligence to efficiently process the sensor event on location and thereby saves the costly wireless...

  19. Some Challenges in Wireless Security

    National Research Council Canada - National Science Library

    Banerjee, Suman

    2007-01-01

    Wireless communication technologies provide users with significant flexibility and portability and hence is being widely adopted as a preferred mode of communication in many military and civilian applications...

  20. Smart Home Wireless Sensor Nodes

    DEFF Research Database (Denmark)

    Lynggaard, Per

    . This paper introduces an approach that considerably lowers the wireless sensor node power consumption and the amount of transmitted sensor events. It uses smart objects that include artificial intelligence to efficiently process the sensor event on location and thereby saves the costly wireless......Smart homes are further development of intelligent buildings and home automation, where context awareness and autonomous behaviour are added. They are based on a combination of the Internet and emerging technologies like wireless sensor nodes. These wireless sensor nodes are challenging because...

  1. Secure Geographic Routing in Ad Hoc and Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Zahariadis Theodore

    2010-01-01

    Full Text Available Security in sensor networks is one of the most relevant research topics in resource constrained wireless devices and networks. Several attacks can be suffered in ad hoc and wireless sensor networks (WSN, which are highly susceptible to attacks, due to the limited resources of the nodes. In this paper, we propose innovative and lightweight localization techniques that allow for intrusion identification and isolation schemes and provide accurate location information. This information is used by our routing protocol which additionally incorporates a distributed trust model to prevent several routing attacks to the network. We finally evaluate our algorithms for accurate localization and for secure routing which have been implemented and tested in real ad hoc and wireless sensor networks.

  2. Challenge Study: A Project-Based Learning on a Wireless Communication System at Technical High School

    Science.gov (United States)

    Terasawa, Ikuo

    2016-01-01

    The challenge study is a project based learning curriculum at Technical High School aimed at the construction of a wireless communication system. The first period was engineering issues in the construction of an artificial satellite and the second period was a positional locating system based on the general purpose wire-less device--ZigBee device.…

  3. Cognitive wireless networks

    CERN Document Server

    Feng, Zhiyong; Zhang, Ping

    2015-01-01

    This brief examines the current research in cognitive wireless networks (CWNs). Along with a review of challenges in CWNs, this brief presents novel theoretical studies and architecture models for CWNs, advances in the cognitive information awareness and delivery, and intelligent resource management technologies. The brief presents the motivations and concepts of CWNs, including theoretical studies of temporal and geographic distribution entropy as well as cognitive information metrics. A new architecture model of CWNs is proposed with theoretical, functional and deployment architectures suppo

  4. Close or positive margins after surgical resection for the head and neck cancer patient: the addition of brachytherapy improves local control

    International Nuclear Information System (INIS)

    Beitler, Jonathan J.; Smith, Richard V.; Silver, Carl E.; Quish, Astrid; Deore, Shivaji M.; Mullokandov, Eduard; Fontenla, Doracy P.; Wadler, Scott; Hayes, Mary Katherine; Vikram, Bhadrasain

    1998-01-01

    Purpose: Microscopically positive or close margins after surgical resection results in an approximately 21-26% local failure rate despite excellent postoperative external radiation therapy. We sought to demonstrate improved local control in head and neck cancer patients who had a resection with curative intent, and had unexpected, microscopically positive or close surgical margins. Methods and Materials: Twenty-nine patients with microscopically close or positive margins after curative surgery were given definitive, adjuvant external radiation therapy and 125 I brachytherapy. All 29 patients had squamous cell cancer and tonsil was the most common subsite within the head and neck region. After external radiation therapy and thorough discussions with the attending surgeon and pathologists, the slides, gross specimens, and appropriate radiographs were reviewed and a target volume was determined. The target volume was the region of the margin in question and varied in size based on the surgery and pathologic results. Once the target volume was identified the patient was taken back to the operating room for insertion of 125 I seeds. Activity implanted (range 2.9-21.5 millicuries) was designed to administer a cumulative lifetime dose of 120-160 Gy. Results: Twenty-nine patients were followed for a median of 26 months (range 5-86 months). Two-year actuarial local control was 92%. Conclusion: 125 I, after external radiation therapy, is an excellent method to improve local control in the subset of patients with unexpectedly unsatisfactory margins

  5. Spatio-temporal distribution of injured elephants in Masai Mara and the putative negative and positive roles of the local community.

    Science.gov (United States)

    Mijele, Domnic; Obanda, Vincent; Omondi, Patrick; Soriguer, Ramón C; Gakuya, Francis; Otiende, Moses; Hongo, Peter; Alasaad, Samer

    2013-01-01

    Very few studies have ever focused on the elephants that are wounded or killed as local communities attempt to scare these animals away from their settlements and farms, or on the cases in which local people take revenge after elephants have killed or injured humans. On the other hand, local communities live in close proximity to elephants and hence can play a positive role in elephant conservation by informing the authorities of the presence of injured elephants. Between 2007 and 2011, 129 elephants were monitored in Masai Mara (Kenya), of which 54 had various types of active (intentionally caused) or passive (non-intentionally caused) injuries. Also studied were 75 random control samples of apparently unaffected animals. The observed active injuries were as expected biased by age, with adults suffering more harm; on the other hand, no such bias was observed in the case of passive injuries. Bias was also observed in elephant sex since more males than females were passively and actively injured. Cases of passive and active injuries in elephants were negatively related to the proximity to roads and farms; the distribution of injured elephants was not affected by the presence of either human settlements or water sources. Overall more elephants were actively injured during the dry season than the wet season as expected. Local communities play a positive role by informing KWS authorities of the presence of injured elephants and reported 43% of all cases of injured elephants. Our results suggest that the negative effect of local communities on elephants could be predicted by elephant proximity to farms and roads. In addition, local communities may be able to play a more positive role in elephant conservation given that they are key informants in the early detection of injured elephants.

  6. The Impact of Hands-On Simulation Laboratories on Teaching of Wireless Communications

    Directory of Open Access Journals (Sweden)

    Te-Shun Chou

    2017-03-01

    Full Text Available Aim/Purpose: To prepare students with both theoretical knowledge and practical skills in the field of wireless communications. Background: Teaching wireless communications and networking is not an easy task because it involves broad subjects and abstract content. Methodology: A pedagogical method that combined lectures, labs, assignments, exams, and readings was applied in a course of wireless communications. Contribution: Five wireless networking labs, related to wireless local networks, wireless security, and wireless sensor networks, were developed for students to complete all of the required hands-on lab activities. Findings: Both development and implementation of the labs achieved a successful outcome and provided students with a very effective learning experience. Students expressed that they had a better understanding of different wireless network technologies after finishing the labs. Recommendations for Practitioners: Detailed instructional lab manuals should be developed so that students can carry out hands-on activities in a step-by-step fashion. Recommendation for Researchers: Hands-on lab exercises can not only help students understand the abstract technical terms in a meaningful way, but also provide them with hands-on learning experience in terms of wireless network configuration, implementation, and evaluation. Impact on Society: With the help of a wireless network simulator, students have successfully enhanced their practical skills and it would benefit them should they decide to pursue a career in wireless network design or implementation. Future Research: Continuous revision of the labs will be made according to the feedback from students. Based on the experience, more wireless networking labs and network issues could be studied in the future.

  7. From early wireless to Everest.

    Science.gov (United States)

    Allen, A

    1998-01-01

    Medical information has been transmitted using wireless technologies for almost 80 years. A "wired wireless" electronic stethoscope was developed by the U.S. Army Signal Corps in the early 1920's, for potential use in ship-to-shore transmission of cardiac sounds. [Winters SR. Diagnosis by wireless. Scientific American June 11, 1921, p. 465] Today, wireless is used in a wide range of medical applications and at sites from transoceanic air flights to offshore oil platforms to Mt. Everest. 'Wireless LANs' are often used in medical environments. Typically, nurses and physicians in a hospital or clinic use hand-held "wireless thin client" pen computers that exchange patient information and images with the hospital server. Numerous companies, such as Fujitsu (article below) and Cruise Technologies (www.cruisetech.com) manufacture handheld pen-entry computers. One company, LXE, integrates radio-frequency (RF) enhanced hand-held computers specifically designed for production use within a wireless LAN (www.lxe.com). Other companies (Proxim, Symbol, and others) supply the wireless RF LAN infrastructure for the enterprise. Unfortunately, there have been problems with widespread deployment of wireless LANs. Perhaps the biggest impediment has been the lack of standards. Although an international standard (IEEE 802.11) was adopted in 1997, most wireless LAN products still are not compatible with the equipment of competing companies. A problem with the current standard for LAN adapters is that throughput is limited to 3 Mbps--compared to at least 10 Mbps, and often 100 Mbps, in a hard-wired Ethernet LAN. An II Mbps standard is due out in the next year or so, but it will be at least 2 years before standards-compliant products are available. This story profiles some of the ways that wireless is being used to overcome gaps in terrestrial and within-enterprise communication.

  8. Comparison of methods for localizing the source position of deauthentication attacks on WAP 802.11n using Chanalyzer and Wi-Spy 2.4x

    Science.gov (United States)

    Bahaweres, R. B.; Mokoginta, S.; Alaydrus, M.

    2017-01-01

    This paper descnbes a comparison of three methods used to locate the position of the source of deauthentication attacks on Wi-Fi using Chanalyzer, and Wi-Spy 2.4x adapter. The three methods are wardriving, absorption and trilateration. The position of constant deauthentication attacks is more easily analyzed compared to that of random attacks. Signal propagation may provide a comparison between signal strength and distance which makes the position of attackers more easily located. The results are shown on the chart patterns generated from the Received Signal Strength Indicator (RSS). And it is proven that these three methods can be used to localize the position of attackers, and can be recommended for use in the environment of organizations using Wi-Fi.

  9. Distributed topology control algorithm to conserve energy in heterogeneous wireless mesh networks

    CSIR Research Space (South Africa)

    Aron, FO

    2008-07-01

    Full Text Available to increasing the network capacity via better spatial bandwidth reuse. In this work, the problem of topology control in a hybrid WMN of heterogeneous wireless devices with varying maximum transmission ranges is considered. A localized distributed topology...

  10. Wireless microwave acoustic sensor system for condition monitoring in power plant environments

    Energy Technology Data Exchange (ETDEWEB)

    Pereira da Cunha, Mauricio [Univ. of Maine, Orno, ME (United States)

    2017-03-30

    This project successfully demonstrated novel wireless microwave acoustic temperature and pressure sensors that can be embedded into equipment and structures located in fossil fuel power plant environments to monitor the condition of components such as steam headers, re-heat lines, water walls, burner tubes, and power turbines. The wireless microwave acoustic sensor technology researched and developed through a collaborative partnership between the University of Maine and Environetix Technologies Corporation can provide a revolutionary impact in the power industry since it is anticipated that the wireless sensors will deliver reliable real-time sensing information in harsh power plant conditions that involve temperatures up to 1100oC and pressures up to 750 psi. The work involved the research and development of novel high temperature harsh environment thin film electrodes, piezoelectric smart microwave acoustic sensing elements, sensor encapsulation materials that were engineered to function over long times up to 1100oC, and a radio-frequency (RF) wireless interrogation electronics unit that are located both inside and outside the high temperature harsh environment. The UMaine / Environetix team have interacted with diverse power plant facilities, and identified as a testbed a local power generation facility, which burns municipal solid waste (MSW), the Penobscot Energy Recovery Company (PERC), Orrington, Maine. In this facility Environetix / UMaine successfully implemented and tested multiple wireless temperature sensor systems within the harsh-environment of the economizer chamber and at the boiler tubes, transferring the developed technology to the power plant environment to perform real-time sensor monitoring experiments under typical operating conditions, as initially targeted in the project. The wireless microwave acoustic sensor technology developed under this project for power plant applications offers several significant advantages including wireless

  11. Local search algorithms for a single-machine scheduling problem with positive and negative time-lags

    NARCIS (Netherlands)

    Hurink, Johann L.; Keuchel, J.

    1998-01-01

    Positive and negative time-lags are general timing restrictions between the starting times of jobs which have been introduced in connection with the Metra potential method. Although very powerful, these relations have been considered only seldom in the literature since already for a single machine

  12. Local search algorithms for a single-machine scheduling problem with positive and negative time-lags

    NARCIS (Netherlands)

    Hurink, Johann L.; Keuchel, J.

    Positive and negative time-lags are general timing restrictions between the starting times of jobs which have been introduced by Roy (C.R. Acad. Sci., 1959, T.248) in connection with the Metra Potential Method. Although very powerful, these relations have been considered only seldom in the

  13. The Demethylase JMJD2C Localizes to H3K4me3 Positive Transcription Start Sites and Is Dispensable for Embryonic Development

    DEFF Research Database (Denmark)

    Pedersen, Marianne Terndrup; Agger, Karl; Laugesen, Anne

    2014-01-01

    cell (ESC) self-renewal and embryonic development. Moreover, we report that JMJD2C localizes to H3K4me3 positive transcription start sites in both primary cells and in the human carcinoma KYSE150 cell line, containing an amplification of the JMJD2C locus. Binding is dependent on the double Tudor domain...... expression of a subset of target genes involved in cell cycle progression. Taken together, we show that JMJD2C is targeted to H3K4me3 positive transcription start sites, where it can contribute to transcriptional regulation, and report that the putative oncogene, JMJD2C, is not generally required...

  14. Development and Application of Wireless Power Transmission Systems for Wireless ECG Sensors

    Directory of Open Access Journals (Sweden)

    Jin-Chul Heo

    2018-01-01

    Full Text Available We investigated the variations in the magnetic field distribution and power transmission efficiency, resulting from changes in the relative positions of the transmitting and receiving coils, for electromagnetic induction-type wireless power transmission using an elliptical receive coil. Results of simulations using a high-frequency structure simulator were compared to actual measurement results. The simulations showed that the transmission efficiency could be maintained relatively stable even if the alignment between the transmitting and receiving coils was changed to some extent. When the centre of the receiving coil was perfectly aligned with the centre of the transmitting coil, the transmission efficiency was in the maximum; however, the degree of decrease in the transmission efficiency was small even if the centre of the receiving coil moved by ±10 mm from the centre of the transmitting coil. Therefore, it is expected that the performance of the wireless power transmission system will not be degraded significantly even if perfect alignment is not maintained. Animal experiments confirmed good ECG signals for the simulation conditions. The results suggested a standardized application method of wireless transmission in the utilization of wireless power for implantable sensors.

  15. Attacks on IEEE 802.11 wireless networks

    Directory of Open Access Journals (Sweden)

    Dejan Milan Tepšić

    2013-06-01

    . Antennas are an integral part of wireless networks. A selected antenna type affects performance, network availability and safety of wireless networks. Finding default values CommView for WiFi is a tool for monitoring data flow (sniffer especially written for wireless networks. Cain & Abel is a universal tool for the detection of all types of passwords. If a wireless network uses a protective mechanism of MAC address filtering, then the attacker must collect the IP addresses. To connect to a wireless access point, it is necessary to know its SSID. Contrary to what some people think, SSID is not a password. Wardriving Driving a car with a portable computer aimed at the detection of wireless computer networks, onto which connection is later possible, is called wardriving. For wardriving, it is necessary to have an appropriate software tool and a wireless network card or an adapter, on which an external antenna can be added to increase signal strength. It is also possible to use a global positioning device (GPS to determine the coordinates of the detected wireless access points on a map. The most widely used software tools for wardriving are Network Stumbler, Kismet and MiniStumbler. Network attacks Hackers’ most usual attack to circumvent the basic access control in wireless networks is masking their own MAC address with an MAC address of a legitimate client on the network (MAC address spoofing. Man-in-the-Middle attack inserts the attacker’s system in the middle between wireless clients and the wireless access point. Legitimate wireless users will be fooled when they try to connect, by being associated to the attacker's system instead of the legitimate wireless access point. The ARP table poisoning attack inserts the attacker's system in the middle of communication between legitimate clients and the wireless access point. Attackers could use the address resolution protocol if it is running on the network. The aim of this attack is to introduce an attacker as a legitimate

  16. Green Wireless Power Transfer Networks

    NARCIS (Netherlands)

    Liu, Q.; Golinnski, M.; Pawelczak, P.; Warnier, M.

    2016-01-01

    wireless power transfer network (WPTN) aims to support devices with cable-less energy on-demand. Unfortunately, wireless power transfer itself-especially through radio frequency radiation rectification-is fairly inefficient due to decaying power with distance, antenna polarization, etc.

  17. Wireless Networks: a brief introduction

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Wireless Networks: a brief introduction. Wireless communication: What? Why? How many types? What is cell? Is it different from fixed landline structure? 1G systems: FDMA/FDD and Analog FM [voice comm]. (Introduced in 1983 in Chicago by AMPS). 2G systems: 3 ...

  18. An Analysis Of Wireless Security

    OpenAIRE

    Salendra Prasad

    2017-01-01

    The WLAN security includes Wired Equivalent Primary WEP and WI-FI protected Access WPA. Today WEP is regarded as very poor security standard. WEP was regarded as very old security standard and has many security issues which users need to be addressed. In this Paper we will discuss Wireless Security and ways to improve on wireless security.

  19. Optimal transmission schemes in wireless networks and their comparison with simple ALOHA based scheme

    OpenAIRE

    Jacquet, Philippe; Malik, Salman

    2010-01-01

    We present our analysis and results that allow us to conjecture that maximum capacity in wireless networks can be achieved if nodes transmitting simultaneously are positioned in a hexagonal grid pattern. But obviously, it is very difficult to realize such a protocol which ensures that active transmitters in the network are positioned in any specific grid pattern. We compare the optimal capacity in networks with grid positioned transmitters with the capacity of wireless networks where nodes ar...

  20. Energy efficient topology for Wireless Mesh Networks | Negash ...

    African Journals Online (AJOL)

    We analyze the power control problem using coalition formation game theory employing utilities based on the coverage areas of the access points by associating a cost function with the utility as the payoff of the coalition members. Our work focuses on the access layer of a wireless mesh local area network. We show that by ...

  1. Capacity allocation in wireless communication networks - models and analyses

    NARCIS (Netherlands)

    Litjens, Remco

    2003-01-01

    This monograph has concentrated on capacity allocation in cellular and Wireless Local Area Networks, primarily with a network operator’s perspective. In the introduc- tory chapter, a reference model has been proposed for the extensive suite of capacity allocation mechanisms that can be applied at

  2. Weighted Least Squares Techniques for Improved Received Signal Strength Based Localization

    Directory of Open Access Journals (Sweden)

    José R. Casar

    2011-09-01

    Full Text Available The practical deployment of wireless positioning systems requires minimizing the calibration procedures while improving the location estimation accuracy. Received Signal Strength localization techniques using propagation channel models are the simplest alternative, but they are usually designed under the assumption that the radio propagation model is to be perfectly characterized a priori. In practice, this assumption does not hold and the localization results are affected by the inaccuracies of the theoretical, roughly calibrated or just imperfect channel models used to compute location. In this paper, we propose the use of weighted multilateration techniques to gain robustness with respect to these inaccuracies, reducing the dependency of having an optimal channel model. In particular, we propose two weighted least squares techniques based on the standard hyperbolic and circular positioning algorithms that specifically consider the accuracies of the different measurements to obtain a better estimation of the position. These techniques are compared to the standard hyperbolic and circular positioning techniques through both numerical simulations and an exhaustive set of real experiments on different types of wireless networks (a wireless sensor network, a WiFi network and a Bluetooth network. The algorithms not only produce better localization results with a very limited overhead in terms of computational cost but also achieve a greater robustness to inaccuracies in channel modeling.

  3. Local administration of calcitriol positively influences bone remodeling and maturation during restoration of mandibular bone defects in rats

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hongrui; Cui, Jian; Feng, Wei; Lv, Shengyu; Du, Juan; Sun, Jing; Han, Xiuchun [Department of Bone Metabolism, School of Stomatology Shandong University, Shandong Provincial Key Laboratory of Oral Biomedicine, Jinan (China); Wang, Zhenming; Lu, Xiong [Key Lab of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan (China); Yimin [Department of Advanced Medicine, Graduate School of Medicine, Hokkaido University, Sapporo (Japan); Oda, Kimimitsu [Division of Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, Niigata (Japan); Amizuka, Norio [Department of Developmental Biology of Hard Tissue, Graduate School of Dental Medicine, Hokkaido University, Sapporo (Japan); Li, Minqi, E-mail: liminqi@sdu.edu.cn [Department of Bone Metabolism, School of Stomatology Shandong University, Shandong Provincial Key Laboratory of Oral Biomedicine, Jinan (China)

    2015-04-01

    The aim of this study was to investigate the influence of calcitriol on osteoinduction following local administration into mandibular bone defects. Calcitriol-loaded absorbable collagen membrane scaffolds were prepared using the polydopamine coating method and characterized by scanning electron microscopy. Composite scaffolds were implanted into rat mandibular bone defects in the following groups: no graft material (control), bare collagen membrane (CM group), collagen membrane bearing polydopamine coating (DOP/CM group), and collagen membrane bearing polydopamine coating absorbed with calcitriol (CAL/DOP/CM group). At 1, 2, 4 and 8 weeks post-surgery, the osteogenic potential of calcitriol was examined by histological and immunohistochemical methods. Following in vivo implantation, calcitriol-loaded composite scaffolds underwent rapid degradation with pronounced replacement by new bone and induced reunion of the bone marrow cavity. Calcitriol showed strong potential in inhibiting osteoclastogenesis and promotion of osteogenic differentiation at weeks 1, and 2. Furthermore, statistical analysis revealed that the newly formed bone volume in the CAL/DOP/CM group was significantly higher than other groups at weeks 1, and 2. At weeks 4, and 8, the CAL/DOP/CM group showed more mineralized bone and uniform collagen structure. These data suggest that local administration of calcitriol is promising in promoting osteogenesis and mineralization for restoration of mandibular bone defects. - Highlights: • More information on collagen material was added in the revised manuscript. • Masson–Goldner trichrome stain was performed for histomorphometry. • More specific information on calcitriol was supplemented in the Discussion section. • The MOD of ALP and Runx2 was explained in more detail. • The inhibition of osteoclastogenesis was described more accurately in the second paragraph of the discussion.

  4. The Hippo component YAP localizes in the nucleus of human papilloma virus positive oropharyngeal squamous cell carcinoma.

    Science.gov (United States)

    Alzahrani, Faisal; Clattenburg, Leanne; Muruganandan, Shanmugam; Bullock, Martin; MacIsaac, Kaitlyn; Wigerius, Michael; Williams, Blair A; Graham, M Elise R; Rigby, Matthew H; Trites, Jonathan R B; Taylor, S Mark; Sinal, Christopher J; Fawcett, James P; Hart, Robert D

    2017-02-22

    HPV infection causes cervical cancer, mediated in part by the degradation of Scribble via the HPV E6 oncoprotein. Recently, Scribble has been shown to be an important regulator of the Hippo signaling cascade. Deregulation of the Hippo pathway induces an abnormal cellular transformation, epithelial to mesenchymal transition, which promotes oncogenic progression. Given the recent rise in oropharyngeal HPV squamous cell carcinoma we sought to determine if Hippo signaling components are implicated in oropharyngeal squamous cell carcinoma. Molecular and cellular techniques including immunoprecipiations, Western blotting and immunocytochemistry were used to identify the key Hippo pathway effector Yes-Associated Protein (YAP)1. Oropharyngeal tissue was collected from CO 2 laser resections, and probed with YAP1 antibody in tumor and pre-malignant regions of HPV positive OPSCC tissue. This study reveals that the Scribble binding protein Nitric Oxide Synthase 1 Adaptor Protein (NOS1AP) forms a complex with YAP. Further, the NOS1APa and NOS1APc isoforms show differential association with activated and non-activated YAP, and impact cellular proliferation. Consistent with deregulated Hippo signaling in OPSCC HPV tumors, we see a delocalization of Scribble and increased nuclear accumulation of YAP1 in an HPV-positive OPSCC. Our preliminary data indicates that NOS1AP isoforms differentially associate with YAP1, which, together with our previous findings, predicts that loss of YAP1 enhances cellular transformation. Moreover, YAP1 is highly accumulated in the nucleus of HPV-positive OPSCC, implying that Hippo signaling and possibly NOS1AP expression are de-regulated in OPSCC. Further studies will help determine if NOS1AP isoforms, Scribble and Hippo components will be useful biomarkers in OPSCC tumor biology.

  5. Evidence of positive selection at codon sites localized in extracellular domains of mammalian CC motif chemokine receptor proteins

    Directory of Open Access Journals (Sweden)

    Metzger Kelsey J

    2010-05-01

    Full Text Available Abstract Background CC chemokine receptor proteins (CCR1 through CCR10 are seven-transmembrane G-protein coupled receptors whose signaling pathways are known for their important roles coordinating immune system responses through targeted trafficking of white blood cells. In addition, some of these receptors have been identified as fusion proteins for viral pathogens: for example, HIV-1 strains utilize CCR5, CCR2 and CCR3 proteins to obtain cellular entry in humans. The extracellular domains of these receptor proteins are involved in ligand-binding specificity as well as pathogen recognition interactions. In mammals, the majority of chemokine receptor genes are clustered together; in humans, seven of the ten genes are clustered in the 3p21-24 chromosome region. Gene conversion events, or exchange of DNA sequence between genes, have been reported in chemokine receptor paralogs in various mammalian lineages, especially between the cytogenetically closely located pairs CCR2/5 and CCR1/3. Datasets of mammalian orthologs for each gene were analyzed separately to minimize the potential confounding impact of analyzing highly similar sequences resulting from gene conversion events. Molecular evolution approaches and the software package Phylogenetic Analyses by Maximum Likelihood (PAML were utilized to investigate the signature of selection that has acted on the mammalian CC chemokine receptor (CCR gene family. The results of neutral vs. adaptive evolution (positive selection hypothesis testing using Site Models are reported. In general, positive selection is defined by a ratio of nonsynonymous/synonymous nucleotide changes (dN/dS, or ω >1. Results Of the ten mammalian CC motif chemokine receptor sequence datasets analyzed, only CCR2 and CCR3 contain amino acid codon sites that exhibit evidence of positive selection using site based hypothesis testing in PAML. Nineteen of the twenty codon sites putatively indentified as likely to be under positive

  6. On the position of local levels of defects in proton-irradiated Pb1-xSnxTe alloys

    International Nuclear Information System (INIS)

    Brandt, N.B.; Gas'kov, A.M.; Ladygin, E.A.; Skipetrov, E.P.; Khorosh, A.G.

    1989-01-01

    Effect of fast proton irradiation (T≅300 K, E=200 keV, F≤2x10 14 cm -2 ) on electrophysical properties of thin layers p-Pb 1-x Sn x Te (0.17 ≤x≤ 0.26) is investigated. Saturation of radiation flux dependences of hole density due to occurrence of a resonance level under irradiation, which is near the ceiling of the valence band of alloys, and due to stabilization of the Fermi level with the resonance level is detected. Possibility of coordination of novadays data on the position of the levels of radiation defects in alloys Pb 1-x Sn x Te is discussed

  7. Whole-body and local RF absorption in human models as a function of anatomy and position within 1.5T MR body coil.

    Science.gov (United States)

    Murbach, Manuel; Neufeld, Esra; Kainz, Wolfgang; Pruessmann, Klaas P; Kuster, Niels

    2014-02-01

    Radiofrequency energy deposition in magnetic resonance imaging must be limited to prevent excessive heating of the patient. Correlations of radiofrequency absorption with large-scale anatomical features (e.g., height) are investigated in this article. The specific absorption rate (SAR), as the pivotal parameter for quantifying absorbed radiofrequency, increases with the radial dimension of the patient and therefore with the large-scale anatomical properties. The absorbed energy in six human models has been modeled in different Z-positions (head to knees) within a 1.5T bodycoil. For a fixed B1+ incident field, the whole-body SAR can be up to 2.5 times higher (local SAR up to seven times) in obese adult models compared to children. If the exposure is normalized to 4 W/kg whole-body SAR, the local SAR can well-exceed the limits for local transmit coils and shows intersubject variations of up to a factor of three. The correlations between anatomy and induced local SAR are weak for normalized exposure, but strong for a fixed B1+ field, suggesting that anatomical properties could be used for fast SAR predictions. This study demonstrates that a representative virtual human population is indispensable for the investigation of local SAR levels. Copyright © 2013 Wiley Periodicals, Inc.

  8. Wireless remote monitoring system for sleep apnea

    Science.gov (United States)

    Oh, Sechang; Kwon, Hyeokjun; Varadan, Vijay K.

    2011-04-01

    Sleep plays the important role of rejuvenating the body, especially the central nervous system. However, more than thirty million people suffer from sleep disorders and sleep deprivation. That can cause serious health consequences by increasing the risk of hypertension, diabetes, heart attack and so on. Apart from the physical health risk, sleep disorders can lead to social problems when sleep disorders are not diagnosed and treated. Currently, sleep disorders are diagnosed through sleep study in a sleep laboratory overnight. This involves large expenses in addition to the inconvenience of overnight hospitalization and disruption of daily life activities. Although some systems provide home based diagnosis, most of systems record the sleep data in a memory card, the patient has to face the inconvenience of sending the memory card to a doctor for diagnosis. To solve the problem, we propose a wireless sensor system for sleep apnea, which enables remote monitoring while the patient is at home. The system has 5 channels to measure ECG, Nasal airflow, body position, abdominal/chest efforts and oxygen saturation. A wireless transmitter unit transmits signals with Zigbee and a receiver unit which has two RF modules, Zigbee and Wi-Fi, receives signals from the transmitter unit and retransmits signals to the remote monitoring system with Zigbee and Wi-Fi, respectively. By using both Zigbee and Wi-Fi, the wireless sensor system can achieve a low power consumption and wide range coverage. The system's features are presented, as well as continuous monitoring results of vital signals.

  9. Influence of pregnancy stage and fetus position on the whole-body and local exposure of the fetus to RF-EMF

    Science.gov (United States)

    Varsier, N.; Dahdouh, S.; Serrurier, A.; De la Plata, J.-P.; Anquez, J.; Angelini, E. D.; Bloch, I.; Wiart, J.

    2014-09-01

    This paper analyzes the influence of pregnancy stage and fetus position on the whole-body and brain exposure of the fetus to radiofrequency electromagnetic fields. Our analysis is performed using semi-homogeneous pregnant woman models between 8 and 32 weeks of amenorrhea. By analyzing the influence of the pregnancy stage on the environmental whole-body and local exposure of a fetus in vertical position, head down or head up, in the 2100 MHz frequency band, we concluded that both whole-body and average brain exposures of the fetus decrease during the first pregnancy trimester, while they advance during the pregnancy due to the rapid weight gain of the fetus in these first stages. From the beginning of the second trimester, the whole-body and the average brain exposures are quite stable because the weight gains are quasi proportional to the absorbed power increases. The behavior of the fetus whole-body and local exposures during pregnancy for a fetus in the vertical position with the head up were found to be of a similar level, when compared to the position with the head down they were slightly higher, especially in the brain.

  10. Influence of pregnancy stage and fetus position on the whole-body and local exposure of the fetus to RF-EMF

    International Nuclear Information System (INIS)

    Varsier, N; Wiart, J; Dahdouh, S; Angelini, E D; Bloch, I; Serrurier, A; De la Plata, J-P; Anquez, J

    2014-01-01

    This paper analyzes the influence of pregnancy stage and fetus position on the whole-body and brain exposure of the fetus to radiofrequency electromagnetic fields. Our analysis is performed using semi-homogeneous pregnant woman models between 8 and 32 weeks of amenorrhea. By analyzing the influence of the pregnancy stage on the environmental whole-body and local exposure of a fetus in vertical position, head down or head up, in the 2100 MHz frequency band, we concluded that both whole-body and average brain exposures of the fetus decrease during the first pregnancy trimester, while they advance during the pregnancy due to the rapid weight gain of the fetus in these first stages. From the beginning of the second trimester, the whole-body and the average brain exposures are quite stable because the weight gains are quasi proportional to the absorbed power increases. The behavior of the fetus whole-body and local exposures during pregnancy for a fetus in the vertical position with the head up were found to be of a similar level, when compared to the position with the head down they were slightly higher, especially in the brain. (paper)

  11. Wireless Headset Communication System

    Science.gov (United States)

    Lau, Wilfred K.; Swanson, Richard; Christensen, Kurt K.

    1995-01-01

    System combines features of pagers, walkie-talkies, and cordless telephones. Wireless headset communication system uses digital modulation on spread spectrum to avoid interference among units. Consists of base station, 4 radio/antenna modules, and as many as 16 remote units with headsets. Base station serves as network controller, audio-mixing network, and interface to such outside services as computers, telephone networks, and other base stations. Developed for use at Kennedy Space Center, system also useful in industrial maintenance, emergency operations, construction, and airport operations. Also, digital capabilities exploited; by adding bar-code readers for use in taking inventories.

  12. Investigating wireless power transfer

    Science.gov (United States)

    St John, Stuart A.

    2017-09-01

    Understanding Physics is a great end in itself, but is also crucial to keep pace with developments in modern technology. Wireless power transfer, known to many only as a means to charge electric toothbrushes, will soon be commonplace in charging phones, electric cars and implanted medical devices. This article outlines how to produce and use a simple set of equipment to both demonstrate and investigate this phenomenon. It presents some initial findings and aims to encourage Physics educators and their students to conduct further research, pushing the bounds of their understanding.

  13. Dynamic wireless sensor networks

    CERN Document Server

    Oteafy, Sharief M A

    2014-01-01

    In this title, the authors leap into a novel paradigm of scalability and cost-effectiveness, on the basis of resource reuse. In a world with much abundance of wirelessly accessible devices, WSN deployments should capitalize on the resources already available in the region of deployment, and only augment it with the components required to meet new application requirements. However, if the required resources already exist in that region, WSN deployment converges to an assignment and scheduling scheme to accommodate for the new application given the existing resources. Such resources are polled

  14. Wired or Wireless Internet?

    DEFF Research Database (Denmark)

    Gimpel, Gregory

    2010-01-01

    This paper finds that network externalities play a minimal role in the choice of internet access technology. Potential adopters of mobile laptop internet view broadband technology as a black box, the technological details of which donot matter. The study uses qualitative techniques to explore how...... the speed of technological obsolescence, market share dominance, and the black boxing of technology influence consumer intention to adopt WiMax and 3G wireless internet for their laptop computers. The results, implications for industry, and areas for further research are discussed....

  15. Wireless installation standard

    International Nuclear Information System (INIS)

    Lim, Hwang Bin

    2007-12-01

    This is divided six parts which are radio regulation law on securing of radio resource, use of radio resource, protection of radio resource, radio regulation enforcement ordinance with securing, distribution and assignment of radio regulation, radio regulation enforcement regulation on utility of radio resource and technical qualification examination, a wireless installation regulation of technique standard and safety facility standard, radio regulation such as certification regulation of information communicative machines and regulation of radio station on compliance of signal security, radio equipment in radio station, standard frequency station and emergency communication.

  16. Fast Measurement and Reconstruction of Large Workpieces with Freeform Surfaces by Combining Local Scanning and Global Position Data

    Directory of Open Access Journals (Sweden)

    Zhe Chen

    2015-06-01

    Full Text Available In this paper, we propose a new approach for the measurement and reconstruction of large workpieces with freeform surfaces. The system consists of a handheld laser scanning sensor and a position sensor. The laser scanning sensor is used to acquire the surface and geometry information, and the position sensor is utilized to unify the scanning sensors into a global coordinate system. The measurement process includes data collection, multi-sensor data fusion and surface reconstruction. With the multi-sensor data fusion, errors accumulated during the image alignment and registration process are minimized, and the measuring precision is significantly improved. After the dense accurate acquisition of the three-dimensional (3-D coordinates, the surface is reconstructed using a commercial software piece, based on the Non-Uniform Rational B-Splines (NURBS surface. The system has been evaluated, both qualitatively and quantitatively, using reference measurements provided by a commercial laser scanning sensor. The method has been applied for the reconstruction of a large gear rim and the accuracy is up to 0.0963 mm. The results prove that this new combined method is promising for measuring and reconstructing the large-scale objects with complex surface geometry. Compared with reported methods of large-scale shape measurement, it owns high freedom in motion, high precision and high measurement speed in a wide measurement range.

  17. Passive wireless sensing tags NASA inflatable structures.

    Energy Technology Data Exchange (ETDEWEB)

    Brocato, Robert Wesley

    2006-03-01

    This report gives a description of several types of wireless, unpowered remote sensors. Surface acoustic wave (SAW) devices were coupled with conventional sensors to create entirely new types of sensors. These sensors report physically measurable data in the same manner as the conventional sensors, but they do it remotely and without any local power source. The sensors are measured remotely using a radar-like interrogation device, and the sensors and their related communication electronics draw all of the power needed for communicating from the radar pulse. The report covers only a description of prototype sensors and not of the manufacturing requirements of these devices.

  18. Subsets of Women With Close or Positive Margins After Breast-Conserving Surgery With High Local Recurrence Risk Despite Breast Plus Boost Radiotherapy

    International Nuclear Information System (INIS)

    Lupe, Krystine; Truong, Pauline T.; Alexander, Cheryl; Lesperance, Mary; Speers, Caroline; Tyldesley, Scott

    2011-01-01

    Purpose: (1) To examine the effect of surgical margin status on local recurrence (LR) and survival following breast-conserving therapy; (2) To identify subsets with close or positive margins with high LR risk despite whole breast radiotherapy (RT) plus boost. Methods and Materials: Subjects were 2,264 women with pT1–3, any N, M0 invasive breast cancer, treated with breast-conserving surgery and whole breast ± boost RT. Five-year Kaplan-Meier (KM) LR, breast cancer–specific and overall survival (BCSS and OS) were compared between cohorts with negative (n = 1,980), close (n = 222), and positive (n = 62) margins. LR rates were analyzed according to clinicopathologic characteristics. Multivariable Cox regression modeling and matched analysis of close/positive margin cases and negative margin controls were performed. Results: Median follow-up was 5.2 years. Boost RT was used in 92% of patients with close or positive margins. Five-year KM LR rates in the negative, close and positive margin cohorts were 1.3%, 4.0%, and 5.2%, respectively (p = 0.001). BCSS and OS were similar in the three margin subgroups. In the close/positive margin cohort, LR rates were 10.2% with age 10% despite whole breast plus boost RT. These patients should be considered for more definitive surgery.

  19. Positive attitudes toward organic, local, and sustainable foods are associated with higher dietary quality among young adults.

    Science.gov (United States)

    Pelletier, Jennifer E; Laska, Melissa N; Neumark-Sztainer, Dianne; Story, Mary

    2013-01-01

    Scant evidence is available on the relationship between preferences for organic, local, sustainable, and nonprocessed foods (ie, alternative food production practices) and dietary quality. This cross-sectional study examined the characteristics and dietary behaviors (eg, consumption of fruits, vegetables, fast food) of young adults who reported placing low, moderate, or high importance on alternative food production practices. A diverse sample of 1,201 students at a 2-year community college and a 4-year public university in the Twin Cities, MN, completed the Student Health and Wellness Study survey in spring 2010. χ(2) tests examined differences in attitudes across demographic characteristics. Linear regression adjusted dietary intake across attitudes. About half (49%) of young adults placed moderate to high importance on alternative production practices, and few demographic differences across attitudes were found. Young adults who placed high importance on alternative production practices consumed 1.3 more servings of fruits and vegetables (Pfood production practices also consumed breakfast approximately 1 more day per week and fast food half as often as those who placed low importance on these practices (Pfood production practices may be well received by this age group. Experimental studies are needed to investigate whether attitudes toward alternative production practices can be manipulated to improve dietary quality. Copyright © 2013 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

  20. Resource management for multimedia services in high data rate wireless networks

    CERN Document Server

    Zhang, Ruonan; Pan, Jianping

    2017-01-01

    This brief offers a valuable resource on principles of quality-of-service (QoS) provisioning and the related link-layer resource management techniques for high data-rate wireless networks. The primary emphasis is on protocol modeling and analysis. It introduces media access control (MAC) protocols, standards of wireless local area networks (WLANs), wireless personal area networks (WPANs), and wireless body area networks (WBANs), discussing their key technologies, applications, and deployment scenarios. The main analytical approaches and models for performance analysis of the fundamental resource scheduling mechanisms, including the contention-based, reservation-based, and hybrid MAC, are presented. To help readers understand and evaluate system performance, the brief contains a range of simulation results. In addition, a thorough bibliography provides an additional tool. This brief is an essential resource for engineers, researchers, students, and users of wireless networks.

  1. EAP-Kerberos: A Low Latency EAP Authentication Method for Faster Handoffs in Wireless Access Networks

    Science.gov (United States)

    Zrelli, Saber; Okabe, Nobuo; Shinoda, Yoichi

    The wireless medium is a key technology for enabling ubiquitous and continuous network connectivity. It is becoming more and more important in our daily life especially with the increasing adoption of networking technologies in many fields such as medical care and transportation systems. Although most wireless technologies nowadays provide satisfying bandwidth and higher speeds, several of these technologies still lack improvements with regard to handoff performance. In this paper, we focus on wireless network technologies that rely on the Extensible Authentication Protocol for mutual authentication between the station and the access network. Such technologies include local area wireless networks (IEEE 802.11) as well as broadband wireless networks (IEEE 802.16). We present a new EAP authentication method based on a three party authentication scheme, namely Kerberos, that considerably shortens handoff delays. Compared to other methods, the proposed method has the advantage of not requiring any changes on the access points, making it readily deployable at reasonable costs.

  2. Local Setup Reproducibility of the Spinal Column When Using Intensity-Modulated Radiation Therapy for Craniospinal Irradiation With Patient in Supine Position

    Energy Technology Data Exchange (ETDEWEB)

    Stoiber, Eva Maria, E-mail: eva.stoiber@med.uni-heidelberg.de [Department of Radiation Oncology, University Hospital Heidelberg, Heidelberg (Germany); Department of Medical Physics, German Cancer Research Center, Heidelberg (Germany); Giske, Kristina [Department of Medical Physics, German Cancer Research Center, Heidelberg (Germany); Schubert, Kai; Sterzing, Florian; Habl, Gregor; Uhl, Matthias; Herfarth, Klaus [Department of Radiation Oncology, University Hospital Heidelberg, Heidelberg (Germany); Bendl, Rolf [Department of Medical Physics, German Cancer Research Center, Heidelberg (Germany); Medical Informatics, Heilbronn University, Heilbronn (Germany); Debus, Juergen [Department of Radiation Oncology, University Hospital Heidelberg, Heidelberg (Germany)

    2011-12-01

    Purpose: To evaluate local positioning errors of the lumbar spine during fractionated intensity-modulated radiotherapy of patients treated with craniospinal irradiation and to assess the impact of rotational error correction on these uncertainties for one patient setup correction strategy. Methods and Materials: 8 patients (6 adults, 2 children) treated with helical tomotherapy for craniospinal irradiation were retrospectively chosen for this analysis. Patients were immobilized with a deep-drawn Aquaplast head mask. Additionally to daily megavoltage control computed tomography scans of the skull, once-a-week positioning of the lumbar spine was assessed. Therefore, patient setup was corrected by a target point correction, derived from a registration of the patient's skull. The residual positioning variations of the lumbar spine were evaluated applying a rigid-registration algorithm. The impact of different rotational error corrections was simulated. Results: After target point correction, residual local positioning errors of the lumbar spine varied considerably. Craniocaudal axis rotational error correction did not improve or deteriorate these translational errors, whereas simulation of a rotational error correction of the right-left and anterior-posterior axis increased these errors by a factor of 2 to 3. Conclusion: The patient fixation used allows for deformations between the patient's skull and spine. Therefore, for the setup correction strategy evaluated in this study, generous margins for the lumbar spinal target volume are needed to prevent a local geographic miss. With any applied correction strategy, it needs to be evaluated whether or not a rotational error correction is beneficial.

  3. A wireless implantable switched-capacitor based optogenetic stimulating system.

    Science.gov (United States)

    Lee, Hyung-Min; Kwon, Ki-Yong; Li, Wen; Ghovanloo, Maysam

    2014-01-01

    This paper presents a power-efficient implantable optogenetic interface using a wireless switched-capacitor based stimulating (SCS) system. The SCS efficiently charges storage capacitors directly from an inductive link and periodically discharges them into an array of micro-LEDs, providing high instantaneous power without affecting wireless link and system supply voltage. A custom-designed computer interface in LabVIEW environment wirelessly controls stimulation parameters through the inductive link, and an optrode array enables simultaneous neural recording along with optical stimulation. The 4-channel SCS system prototype has been implemented in a 0.35-μm CMOS process and combined with the optrode array. In vivo experiments involving light-induced local field potentials verified the efficacy of the SCS system. An implantable version of the SCS system with flexible hermetic sealing is under development for chronic experiments.

  4. A Wireless Implantable Switched-Capacitor Based Optogenetic Stimulating System

    Science.gov (United States)

    Lee, Hyung-Min; Kwon, Ki-Yong; Li, Wen

    2015-01-01

    This paper presents a power-efficient implantable optogenetic interface using a wireless switched-capacitor based stimulating (SCS) system. The SCS efficiently charges storage capacitors directly from an inductive link and periodically discharges them into an array of micro-LEDs, providing high instantaneous power without affecting wireless link and system supply voltage. A custom-designed computer interface in LabVIEW environment wirelessly controls stimulation parameters through the inductive link, and an optrode array enables simultaneous neural recording along with optical stimulation. The 4-channel SCS system prototype has been implemented in a 0.35-μm CMOS process and combined with the optrode array. In vivo experiments involving light-induced local field potentials verified the efficacy of the SCS system. An implantable version of the SCS system with flexible hermetic sealing is under development for chronic experiments. PMID:25570099

  5. Tracking Mobile Robot in Indoor Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Liping Zhang

    2014-01-01

    Full Text Available This work addresses the problem of tracking mobile robots in indoor wireless sensor networks (WSNs. Our approach is based on a localization scheme with RSSI (received signal strength indication which is used widely in WSN. The developed tracking system is designed for continuous estimation of the robot’s trajectory. A WSN, which is composed of many very simple and cheap wireless sensor nodes, is deployed at a specific region of interest. The wireless sensor nodes collect RSSI information sent by mobile robots. A range-based data fusion scheme is used to estimate the robot’s trajectory. Moreover, a Kalman filter is designed to improve tracking accuracy. Experiments are provided to assess the performance of the proposed scheme.

  6. Hybrid RRM Architecture for Future Wireless Networks

    DEFF Research Database (Denmark)

    Tragos, Elias; Mihovska, Albena D.; Mino, Emilio

    2007-01-01

    The concept of ubiquitous and scalable system is applied in the IST WINNER II [1] project to deliver optimum performance for different deployment scenarios from local area to wide area wireless networks. The integration of cellular and local area networks in a unique radio system will provide...... a great advantage to final users and operators, compared with the nowadays situation with many disconnected systems and users equipped with different subscriptions, radio interfaces and terminals. To this issue, the IST project WINNER II has defined three system modes suited to local, metropolitan...... and wide area respectively. The aim of this paper is twofold: first, it presents an architectural solution for scalable and hybrid radio resource management to efficiently integrate the different WINNER modes; second, it proposes a hybrid handover mechanism to exploit the availability of the different...

  7. Verification of electromagnetic effects from wireless devices in operating nuclear power plants

    Directory of Open Access Journals (Sweden)

    Song-Hae Ye

    2015-10-01

    Full Text Available Wireless communication technologies, especially smartphones, have become increasingly common. Wireless technology is widely used in general industry and this trend is also expected to grow with the development of wireless technology. However, wireless technology is not currently applied in any domestic operating nuclear power plants (NPPs because of the highest priority of the safety policy. Wireless technology is required in operating NPPs, however, in order to improve the emergency responses and work efficiency of the operators and maintenance personnel during its operation. The wired telephone network in domestic NPPs can be simply connected to a wireless local area network to use wireless devices. This design change can improve the ability of the operators and personnel to respond to an emergency situation by using important equipment for a safe shutdown. IEEE 802.11 smartphones (Wi-Fi standard, Internet Protocol (IP phones, personal digital assistant (PDA for field work, notebooks used with web cameras, and remote site monitoring tablet PCs for on-site testing may be considered as wireless devices that can be used in domestic operating NPPs. Despite its advantages, wireless technology has only been used during the overhaul period in Korean NPPs due to the electromagnetic influence of sensitive equipment and cyber security problems. This paper presents the electromagnetic verification results from major sensitive equipment after using wireless devices in domestic operating NPPs. It also provides a solution for electromagnetic interference/radio frequency interference (EMI/RFI from portable and fixed wireless devices with a Wi-Fi communication environment within domestic NPPs.

  8. Verification of electromagnetic effects from wireless devices in operating nuclear power plants

    International Nuclear Information System (INIS)

    Ye, Song Hae; Kim, Young Sik; Lyou, Ho Sun; Kim, Min Suk; Lyou, Joon

    2015-01-01

    Wireless communication technologies, especially smart phones, have become increasingly common. Wireless technology is widely used in general industry and this trend is also expected to grow with the development of wireless technology. However, wireless technology is not currently applied in any domestic operating nuclear power plants (NPPs) because of the highest priority of the safety policy. Wireless technology is required in operating NPPs, however, in order to improve the emergency responses and work efficiency of the operators and maintenance personnel during its operation. The wired telephone network in domestic NPPs can be simply connected to a wireless local area network to use wireless devices. This design change can improve the ability of the operators and personnel to respond to an emergency situation by using important equipment for a safe shutdown. IEEE 802.11 smart phones (Wi-Fi standard), Internet Protocol (IP) phones, personal digital assistant (PDA) for field work, notebooks used with web cameras, and remote site monitoring tablet PCs for on-site testing may be considered as wireless devices that can be used in domestic operating NPPs. Despite its advantages, wireless technology has only been used during the overhaul period in Korean NPPs due to the electromagnetic influence of sensitive equipment and cyber security problems. This paper presents the electromagnetic verification results from major sensitive equipment after using wireless devices in domestic operating NPPs. It also provides a solution for electromagnetic interference/radio frequency interference (EMI/RFI) from portable and fixed wireless devices with a Wi-Fi communication environment within domestic NPPs

  9. Verification of electromagnetic effects from wireless devices in operating nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Song Hae; Kim, Young Sik; Lyou, Ho Sun; Kim, Min Suk [Korea Hydro and Nuclear Power Co. (KHNP), Central Research Institute, Daejeon (Korea, Republic of); Lyou, Joon [Dept. of Electronics Engineering, Chungnam National University, Daejeon (Korea, Republic of)

    2015-10-15

    Wireless communication technologies, especially smart phones, have become increasingly common. Wireless technology is widely used in general industry and this trend is also expected to grow with the development of wireless technology. However, wireless technology is not currently applied in any domestic operating nuclear power plants (NPPs) because of the highest priority of the safety policy. Wireless technology is required in operating NPPs, however, in order to improve the emergency responses and work efficiency of the operators and maintenance personnel during its operation. The wired telephone network in domestic NPPs can be simply connected to a wireless local area network to use wireless devices. This design change can improve the ability of the operators and personnel to respond to an emergency situation by using important equipment for a safe shutdown. IEEE 802.11 smart phones (Wi-Fi standard), Internet Protocol (IP) phones, personal digital assistant (PDA) for field work, notebooks used with web cameras, and remote site monitoring tablet PCs for on-site testing may be considered as wireless devices that can be used in domestic operating NPPs. Despite its advantages, wireless technology has only been used during the overhaul period in Korean NPPs due to the electromagnetic influence of sensitive equipment and cyber security problems. This paper presents the electromagnetic verification results from major sensitive equipment after using wireless devices in domestic operating NPPs. It also provides a solution for electromagnetic interference/radio frequency interference (EMI/RFI) from portable and fixed wireless devices with a Wi-Fi communication environment within domestic NPPs.

  10. Household wireless electroencephalogram hat

    Science.gov (United States)

    Szu, Harold; Hsu, Charles; Moon, Gyu; Yamakawa, Takeshi; Tran, Binh

    2012-06-01

    We applied Compressive Sensing to design an affordable, convenient Brain Machine Interface (BMI) measuring the high spatial density, and real-time process of Electroencephalogram (EEG) brainwaves by a Smartphone. It is useful for therapeutic and mental health monitoring, learning disability biofeedback, handicap interfaces, and war gaming. Its spec is adequate for a biomedical laboratory, without the cables hanging over the head and tethered to a fixed computer terminal. Our improved the intrinsic signal to noise ratio (SNR) by using the non-uniform placement of the measuring electrodes to create the proximity of measurement to the source effect. We computing a spatiotemporal average the larger magnitude of EEG data centers in 0.3 second taking on tethered laboratory data, using fuzzy logic, and computing the inside brainwave sources, by Independent Component Analysis (ICA). Consequently, we can overlay them together by non-uniform electrode distribution enhancing the signal noise ratio and therefore the degree of sparseness by threshold. We overcame the conflicting requirements between a high spatial electrode density and precise temporal resolution (beyond Event Related Potential (ERP) P300 brainwave at 0.3 sec), and Smartphone wireless bottleneck of spatiotemporal throughput rate. Our main contribution in this paper is the quality and the speed of iterative compressed image recovery algorithm based on a Block Sparse Code (Baranuick et al, IEEE/IT 2008). As a result, we achieved real-time wireless dynamic measurement of EEG brainwaves, matching well with traditionally tethered high density EEG.

  11. Biomonitoring with Wireless Communications

    Energy Technology Data Exchange (ETDEWEB)

    Budinger, Thomas F.

    2003-03-01

    This review is divided into three sections: technologies for monitoring physiological parameters; biosensors for chemical assays and wireless communications technologies including image transmissions. Applications range from monitoring high risk patients for heart, respiratory activity and falls to sensing levels of physical activity in military, rescue, and sports personnel. The range of measurements include, heart rate, pulse wave form, respiratory rate, blood oxygen, tissue pCO2, exhaled carbon dioxide and physical activity. Other feasible measurements will employ miniature chemical laboratories on silicon or plastic chips. The measurements can be extended to clinical chemical assays ranging from common blood assays to protein or specialized protein measurements (e.g., troponin, creatine, and cytokines such as TNF and IL6). Though the feasibility of using wireless technology to communicate vital signs has been demonstrated 32 years ago (1) it has been only recently that practical and portable devices and communications net works have become generally available for inexpensive deployment of comfortable and affordable devices and systems.

  12. Early versus deferred androgen suppression therapy for patients with lymph node-positive prostate cancer after local therapy with curative intent: a systematic review

    Science.gov (United States)

    2013-01-01

    Background There is currently no consensus regarding the optimal timing for androgen suppression therapy in patients with prostate cancer that have undergone local therapy with curative intent but are proven to have node-positive disease without signs of distant metastases at the time of local therapy. The objective of this systematic review was to determine the benefits and harms of early (at the time of local therapy) versus deferred (at the time of clinical disease progression) androgen suppression therapy for patients with node-positive prostate cancer after local therapy. Methods The protocol was registered prospectively (CRD42011001221; http://www.crd.york.ac.uk/PROSPERO). We searched the MEDLINE, EMBASE, and CENTRAL databases, as well as reference lists, the abstracts of three major conferences, and three trial registers, to identify randomized controlled trials (search update 04/08/2012). Two authors independently screened the identified articles, assessed trial quality, and extracted data. Results Four studies including 398 patients were identified for inclusion. Early androgen suppression therapy lead to a significant decrease in overall mortality (HR 0.62, 95% CI 0.46-0.84), cancer-specific mortality (HR 0.34, 95% CI 0.18-0.64), and clinical progression at 3 or 9 years (RR 0.29, 95% CI 0.16-0.52 at 3 years and RR 0.49, 95% CI 0.36-0.67 at 9 years). One study showed an increase of adverse effects with early androgen suppression therapy. All trials had substantial methodological limitations. Conclusions The data available suggest an improvement in survival and delayed disease progression but increased adverse events for patients with node-positive prostate cancer after local therapy treated with early androgen suppression therapy versus deferred androgen suppression therapy. However, quality of data is low. Randomized controlled trials with blinding of outcome assessment, planned to determine the timing of androgen suppression therapy in node-positive

  13. Moderate hypofractionated image-guided thoracic radiotherapy for locally advanced node-positive non-small cell lung cancer patients with very limited lung function: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Manapov, Farkhad; Roengvoraphoj, Olarn; Li, Ming Lun; Eze, Chukwuka [Dept. of Radiation Oncology, Ludwig-Maximilian University of Munich, Munich (Germany)

    2017-06-15

    Patients with locally advanced lung cancer and very limited pulmonary function (forced expiratory volume in 1 second [FEV1] ≤ 1 L) have dismal prognosis and undergo palliative treatment or best supportive care. We describe two cases of locally advanced node-positive non-small cell lung cancer (NSCLC) patients with very limited lung function treated with induction chemotherapy and moderate hypofractionated image-guided radiotherapy (Hypo-IGRT). Hypo-IGRT was delivered to a total dose of 45 Gy to the primary tumor and involved lymph nodes. Planning was based on positron emission tomography-computed tomography (PET/ CT) and four-dimensional computed tomography (4D-CT). Internal target volume (ITV) was defined as the overlap of gross tumor volume delineated on 10 phases of 4D-CT. ITV to planning target volume margin was 5 mm in all directions. Both patients showed good clinical and radiological response. No relevant toxicity was documented. Hypo-IGRT is feasible treatment option in locally advanced node-positive NSCLC patients with very limited lung function (FEV1 ≤ 1 L)

  14. Drosophila atm/telomere fusion is required for telomeric localization of HP1 and telomere position effect.

    Science.gov (United States)

    Oikemus, Sarah R; McGinnis, Nadine; Queiroz-Machado, Joana; Tukachinsky, Hanna; Takada, Saeko; Sunkel, Claudio E; Brodsky, Michael H

    2004-08-01

    Terminal deletions of Drosophila chromosomes can be stably protected from end-to-end fusion despite the absence of all telomere-associated sequences. The sequence-independent protection of these telomeres suggests that recognition of chromosome ends might contribute to the epigenetic protection of telomeres. In mammals, Ataxia Telangiectasia Mutated (ATM) is activated by DNA damage and acts through an unknown, telomerase-independent mechanism to regulate telomere length and protection. We demonstrate that the Drosophila homolog of ATM is encoded by the telomere fusion (tefu) gene. In the absence of ATM, telomere fusions occur even though telomere-specific Het-A sequences are still present. High levels of spontaneous apoptosis are observed in ATM-deficient tissues, indicating that telomere dysfunction induces apoptosis in Drosophila. Suppression of this apoptosis by p53 mutations suggests that loss of ATM activates apoptosis through a DNA damage-response mechanism. Loss of ATM reduces the levels of heterochromatin protein 1 (HP1) at telomeres and suppresses telomere position effect. We propose that recognition of chromosome ends by ATM prevents telomere fusion and apoptosis by recruiting chromatin-modifying complexes to telomeres.

  15. A Practical Application Combining Wireless Sensor Networks and Internet of Things: Safety Management System for Tower Crane Groups

    Directory of Open Access Journals (Sweden)

    Dexing Zhong

    2014-07-01

    Full Text Available The so-called Internet of Things (IoT has attracted increasing attention in the field of computer and information science. In this paper, a specific application of IoT, named Safety Management System for Tower Crane Groups (SMS-TC, is proposed for use in the construction industry field. The operating status of each tower crane was detected by a set of customized sensors, including horizontal and vertical position sensors for the trolley, angle sensors for the jib and load, tilt and wind speed sensors for the tower body. The sensor data is collected and processed by the Tower Crane Safety Terminal Equipment (TC-STE installed in the driver’s operating room. Wireless communication between each TC-STE and the Local Monitoring Terminal (LMT at the ground worksite were fulfilled through a Zigbee wireless network. LMT can share the status information of the whole group with each TC-STE, while the LMT records the real-time data and reports it to the Remote Supervision Platform (RSP through General Packet Radio Service (GPRS. Based on the global status data of the whole group, an anti-collision algorithm was executed in each TC-STE to ensure the safety of each tower crane during construction. Remote supervision can be fulfilled using our client software installed on a personal computer (PC or smartphone. SMS-TC could be considered as a promising practical application that combines a Wireless Sensor Network with the Internet of Things.

  16. A practical application combining wireless sensor networks and Internet of Things: Safety Management System for Tower Crane Groups.

    Science.gov (United States)

    Zhong, Dexing; Lv, Hongqiang; Han, Jiuqiang; Wei, Quanrui

    2014-07-30

    The so-called Internet of Things (IoT) has attracted increasing attention in the field of computer and information science. In this paper, a specific application of IoT, named Safety Management System for Tower Crane Groups (SMS-TC), is proposed for use in the construction industry field. The operating status of each tower crane was detected by a set of customized sensors, including horizontal and vertical position sensors for the trolley, angle sensors for the jib and load, tilt and wind speed sensors for the tower body. The sensor data is collected and processed by the Tower Crane Safety Terminal Equipment (TC-STE) installed in the driver's operating room. Wireless communication between each TC-STE and the Local Monitoring Terminal (LMT) at the ground worksite were fulfilled through a Zigbee wireless network. LMT can share the status information of the whole group with each TC-STE, while the LMT records the real-time data and reports it to the Remote Supervision Platform (RSP) through General Packet Radio Service (GPRS). Based on the global status data of the whole group, an anti-collision algorithm was executed in each TC-STE to ensure the safety of each tower crane during construction. Remote supervision can be fulfilled using our client software installed on a personal computer (PC) or smartphone. SMS-TC could be considered as a promising practical application that combines a Wireless Sensor Network with the Internet of Things.

  17. Exploring Processes and Outcomes of Wireless Internet in Higher Education: A Case Study of a University's Early Experience

    Science.gov (United States)

    Lee, Lisa

    2007-01-01

    Many universities in the UK have recently started offering their staff and students free wireless Internet access through Wireless Local Area Network (WLAN) technologies, such as Wi-Fi. Based on a small empirical study of WLAN deployment in a university setting, the article explores adoption processes of the new technology by both the organisation…

  18. Transmit Power Optimisation in Wireless Network

    Directory of Open Access Journals (Sweden)

    Besnik Terziu

    2011-09-01

    Full Text Available Transmit power optimisation in wireless networks based on beamforming have emerged as a promising technique to enhance the spectrum efficiency of present and future wireless communication systems. The aim of this study is to minimise the access point power consumption in cellular networks while maintaining a targeted quality of service (QoS for the mobile terminals. In this study, the targeted quality of service is delivered to a mobile station by providing a desired level of Signal to Interference and Noise Ratio (SINR. Base-stations are coordinated across multiple cells in a multi-antenna beamforming system. This study focuses on a multi-cell multi-antenna downlink scenario where each mobile user is equipped with a single antenna, but where multiple mobile users may be active simultaneously in each cell and are separated via spatial multiplexing using beamforming. The design criteria is to minimize the total weighted transmitted power across the base-stations subject to SINR constraints at the mobile users. The main contribution of this study is to define an iterative algorithm that is capable of finding the joint optimal beamformers for all basestations, based on a correlation-based channel model, the full-correlation model. Among all correlated channel models, the correlated channel model used in this study is the most accurate, giving the best performance in terms of power consumption. The environment here in this study is chosen to be Non-Light of- Sight (NLOS condition, where a signal from a wireless transmitter passes several obstructions before arriving at a wireless receiver. Moreover there are many scatterers local to the mobile, and multiple reflections can occur among them before energy arrives at the mobile. The proposed algorithm is based on uplink-downlink duality using the Lagrangian duality theory. Time-Division Duplex (TDD is chosen as the platform for this study since it has been adopted to the latest technologies in Fourth

  19. Structural processing for wireless communications

    CERN Document Server

    Lu, Jianhua; Ge, Ning

    2015-01-01

    This brief presents an alternative viewpoint on processing technology for wireless communications based on recent research advances. As a lever in emerging processing technology, the structure perspective addresses the complexity and uncertainty issues found in current wireless applications. Likewise, this brief aims at providing a new prospective to the development of communication technology and information science, while stimulating new theories and technologies for wireless systems with ever-increasing complexity. Readers of this brief may range from graduate students to researchers in related fields.

  20. Radio Relays Improve Wireless Products

    Science.gov (United States)

    2009-01-01

    Signal Hill, California-based XCOM Wireless Inc. developed radio frequency micromachine (RF MEMS) relays with a Phase II Small Business Innovation Research (SBIR) contract through NASA?s Jet Propulsion Laboratory. In order to improve satellite communication systems, XCOM produced wireless RF MEMS relays and tunable capacitors that use metal-to-metal contact and have the potential to outperform most semiconductor technologies while using less power. These relays are used in high-frequency test equipment and instrumentation, where increased speed can mean significant cost savings. Applications now also include mainstream wireless applications and greatly improved tactical radios.

  1. Wireless Communications in Smart Grid

    Science.gov (United States)

    Bojkovic, Zoran; Bakmaz, Bojan

    Communication networks play a crucial role in smart grid, as the intelligence of this complex system is built based on information exchange across the power grid. Wireless communications and networking are among the most economical ways to build the essential part of the scalable communication infrastructure for smart grid. In particular, wireless networks will be deployed widely in the smart grid for automatic meter reading, remote system and customer site monitoring, as well as equipment fault diagnosing. With an increasing interest from both the academic and industrial communities, this chapter systematically investigates recent advances in wireless communication technology for the smart grid.

  2. Wireless home networking for dummies

    CERN Document Server

    Briere, Danny; Ferris, Edward

    2010-01-01

    The perennial bestseller shows you how share your files and Internet connection across a wireless network. Fully updated for Windows 7 and Mac OS X Snow Leopard, this new edition of this bestseller returns with all the latest in wireless standards and security. This fun and friendly guide shows you how to integrate your iPhone, iPod touch, smartphone, or gaming system into your home network. Veteran authors escort you through the various financial and logisitical considerations that you need to take into account before building a wireless network at home.: Covers the basics of planning, instal

  3. Microwave materials for wireless applications

    CERN Document Server

    Cruickshank, David B

    2011-01-01

    This practical resource offers you an in-depth, up-to-date understanding of the use of microwave magnetic materials for cutting-edge wireless applications. The book discusses device applications used in wireless infrastructure base stations, point-to-point radio links, and a range of more specialized microwave systems. You find detailed discussions on the attributes of each family of magnetic materials with respect to specific wireless applications. Moreover, the book addresses two of the hottest topics in the field today - insertion loss and intermodulation. This comprehensive reference also

  4. The use of antenna radiation pattern in node localisation algorithms for wireless sensor networks

    CSIR Research Space (South Africa)

    Mwila, MK

    2014-08-01

    Full Text Available Localisation or position determination is one of the most important applications for wireless sensor networks since the locations of the sensor nodes are critical to both network operations and most application level tasks. Numerous techniques...

  5. Wireless device monitoring methods, wireless device monitoring systems, and articles of manufacture

    Science.gov (United States)

    McCown, Steven H [Rigby, ID; Derr, Kurt W [Idaho Falls, ID; Rohde, Kenneth W [Idaho Falls, ID

    2012-05-08

    Wireless device monitoring methods, wireless device monitoring systems, and articles of manufacture are described. According to one embodiment, a wireless device monitoring method includes accessing device configuration information of a wireless device present at a secure area, wherein the device configuration information comprises information regarding a configuration of the wireless device, accessing stored information corresponding to the wireless device, wherein the stored information comprises information regarding the configuration of the wireless device, comparing the device configuration information with the stored information, and indicating the wireless device as one of authorized and unauthorized for presence at the secure area using the comparing.

  6. Frequency-agile antennas for wireless communications

    CERN Document Server

    Petosa, Aldo

    2013-01-01

    Mobile data subscriptions are expected to more than double and mobile wireless traffic to increase by more than tenfold over the next few years. Proliferation of smart phones, tablets, and other portable devices are placing greater demands for services such as web browsing, global positioning, video streaming, and video telephony. Many of the proposed solutions to deal with these demands will have a significant impact on antenna designs. Antennas with frequency agility are considered a promising technology to help implement these new solutions.This book provides readers with a sense of the cap

  7. Localization of WSN using Distributed Particle Swarm Optimization algorithm with precise references

    Science.gov (United States)

    Janapati, Ravi Chander; Balaswamy, Ch.; Soundararajan, K.

    2016-08-01

    Localization is the key research area in Wireless Sensor Networks. Finding the exact position of the node is known as localization. Different algorithms have been proposed. Here we consider a cooperative localization algorithm with censoring schemes using Crammer Rao Bound (CRB). This censoring scheme can improve the positioning accuracy and reduces computation complexity, traffic and latency. Particle swarm optimization (PSO) is a population based search algorithm based on the swarm intelligence like social behavior of birds, bees or a school of fishes. To improve the algorithm efficiency and localization precision, this paper presents an objective function based on the normal distribution of ranging error and a method of obtaining the search space of particles. In this paper Distributed localization algorithm PSO with CRB is proposed. Proposed method shows better results in terms of position accuracy, latency and complexity.

  8. The development of wireless radiation dose monitoring using smart phone

    International Nuclear Information System (INIS)

    Lee, Jin Woo; Jeong, Gyo Seong; Lee, Yun Jong; Kim, Chong Yeal; Lim, Chai Wan

    2016-01-01

    Radiation workers at a nuclear facility or radiation working area should hold personal dosimeters. some types of dosimeters have functions to generate audible or visible alarms to radiation workers. However, such devices used in radiation fields these days have no functions to communicate with other equipment or the responsible personnel. our project aims at the development of a remote wireless radiation dose monitoring system that can be utilized to monitor the radiation dose for radiation workers and to notify the radiation protection manager of the dose information in real time. We use a commercial survey meter for personal radiation measurement and a smart phone for a mobile wireless communication tool and a Beacon for position detection of radiation workers using Blue tooth communication. In this report, the developed wireless dose monitoring of cellular phone is introduced

  9. Low-profile wireless passive resonators for sensing

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Xun; An, Linan

    2017-04-04

    A resonator for sensing a physical or an environmental parameter includes a support having a top surface that provides a ground plane, and a polymer-derived ceramic (PDC) element positioned on the top surface including a PDC layer, and a metal patch on the PDC layer. The metal patch is electrically isolated from all surrounding structure, and the resonator has a resonant frequency that changes as a function of the physical or environmental parameter. A system for wirelessly sensing a physical or environmental parameter includes at least one resonator and a wireless RF reader located remotely from the resonator for transmitting a wide-band RF interrogation signal that excites the resonator. The wireless RF reader detects a sensing signal retransmitted by the resonator and includes a processor for determining the physical or environmental parameter at the location of the resonator from the sensing signal.

  10. Advanced Wireless Integrated Navy Network

    National Research Council Canada - National Science Library

    Stutzman, Warren; Habayeb, Rick

    2005-01-01

    Quarterly progress report No. I on AWINN hardware and software configurations of smart, wideband, multi-function antennas, secure configurable platform, close-in command and control for Sea Basing visualization of wireless...

  11. Wireless Damage Location Sensing System

    Science.gov (United States)

    Woodard, Stanley E. (Inventor); Taylor, Bryant Douglas (Inventor)

    2012-01-01

    A wireless damage location sensing system uses a geometric-patterned wireless sensor that resonates in the presence of a time-varying magnetic field to generate a harmonic response that will experience a change when the sensor experiences a change in its geometric pattern. The sensing system also includes a magnetic field response recorder for wirelessly transmitting the time-varying magnetic field and for wirelessly detecting the harmonic response. The sensing system compares the actual harmonic response to a plurality of predetermined harmonic responses. Each predetermined harmonic response is associated with a severing of the sensor at a corresponding known location thereof so that a match between the actual harmonic response and one of the predetermined harmonic responses defines the known location of the severing that is associated therewith.

  12. Wireless cortical implantable systems

    CERN Document Server

    Majidzadeh Bafar, Vahid

    2013-01-01

    Wireless Cortical Implantable Systems examines the design for data acquisition and transmission in cortical implants. The first part of the book covers existing system-level cortical implants, as well as future devices. The authors discuss the major constraints in terms of microelectronic integration. The second part of the book focuses on system-level as well as circuit and system level solutions to the development of ultra low-power and low-noise microelectronics for cortical implants. Existing solutions are presented and novel methods and solutions proposed. The third part of the book focuses on the usage of digital impulse radio ultra wide-band transmission as an efficient method to transmit cortically neural recorded data at high data-rate to the outside world. Original architectural and circuit and system solutions are discussed.

  13. Wireless Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Hong-Chuan Yang

    2007-01-01

    Full Text Available We study the energy-efficient configuration of multihop paths with automatic repeat request (ARQ mechanism in wireless ad hoc networks. We adopt a cross-layer design approach and take both the quality of each radio hop and the battery capacity of each transmitting node into consideration. Under certain constraints on the maximum tolerable transmission delay and the required packet delivery ratio, we solve optimization problems to jointly schedule the transmitting power of each transmitting node and the retransmission limit over each hop. Numerical results demonstrate that the path configuration methods can either significantly reduce the average energy consumption per packet delivery or considerably extend the average lifetime of the multihop route.

  14. Wireless Josephson amplifier

    International Nuclear Information System (INIS)

    Narla, A.; Sliwa, K. M.; Hatridge, M.; Shankar, S.; Frunzio, L.; Schoelkopf, R. J.; Devoret, M. H.

    2014-01-01

    Josephson junction parametric amplifiers are playing a crucial role in the readout chain in superconducting quantum information experiments. However, their integration with current 3D cavity implementations poses the problem of transitioning between waveguide, coax cables, and planar circuits. Moreover, Josephson amplifiers require auxiliary microwave components, like directional couplers and/or hybrids, that are sources of spurious losses and impedance mismatches that limit measurement efficiency and amplifier tunability. We have developed a wireless architecture for these parametric amplifiers that eliminates superfluous microwave components and interconnects. This greatly simplifies their assembly and integration into experiments. We present an experimental realization of such a device operating in the 9–11 GHz band with about 100 MHz of amplitude gain-bandwidth product, on par with devices mounted in conventional sample holders. The simpler impedance environment presented to the amplifier also results in increased amplifier tunability.

  15. Towards a Decentralized Magnetic Indoor Positioning System

    Directory of Open Access Journals (Sweden)

    Zakaria Kasmi

    2015-12-01

    Full Text Available Decentralized magnetic indoor localization is a sophisticated method for processing sampled magnetic data directly on a mobile station (MS, thereby decreasing or even avoiding the need for communication with the base station. In contrast to central-oriented positioning systems, which transmit raw data to a base station, decentralized indoor localization pushes application-level knowledge into the MS. A decentralized position solution has thus a strong feasibility to increase energy efficiency and to prolong the lifetime of the MS. In this article, we present a complete architecture and an implementation for a decentralized positioning system. Furthermore, we introduce a technique for the synchronization of the observed magnetic field on the MS with the artificially-generated magnetic field from the coils. Based on real-time clocks (RTCs and a preemptive operating system, this method allows a stand-alone control of the coils and a proper assignment of the measured magnetic fields on the MS. A stand-alone control and synchronization of the coils and the MS have an exceptional potential to implement a positioning system without the need for wired or wireless communication and enable a deployment of applications for rescue scenarios, like localization of miners or firefighters.

  16. Accurate and Integrated Localization System for Indoor Environments Based on IEEE 802.11 Round-Trip Time Measurements

    Directory of Open Access Journals (Sweden)

    Lorenzo RubénMateo

    2010-01-01

    Full Text Available The presence of (Non line of Sight NLOS propagation paths has been considered the main drawback for localization schemes to estimate the position of a (Mobile User MU in an indoor environment. This paper presents a comprehensive wireless localization system based on (Round-Trip Time RTT measurements in an unmodified IEEE 802.11 wireless network. It overcomes the NLOS impairment by implementing the (Prior NLOS Measurements Correction PNMC technique. At first, the RTT measurements are performed with a novel electronic circuit avoiding the need for time synchronization between wireless nodes. At second, the distance between the MU and each reference device is estimated by using a simple linear regression function that best relates the RTT to the distance in (Line of Sight LOS. Assuming that LOS in an indoor environment is a simplification of reality hence, the PNMC technique is applied to correct the NLOS effect. At third, assuming known the position of the reference devices, a multilateration technique is implemented to obtain the MU position. Finally, the localization system coupled with measurements demonstrates that the system outperforms the conventional time-based indoor localization schemes without using any tracking technique such as Kalman filters or Bayesian methods.

  17. Unsaturated fatty acids show clear elicitation responses in a modified local lymph node assay with an elicitation phase, and test positive in the direct peptide reactivity assay.

    Science.gov (United States)

    Yamashita, Kunihiko; Shinoda, Shinsuke; Hagiwara, Saori; Miyazaki, Hiroshi; Itagaki, Hiroshi

    2015-12-01

    The Organisation for Economic Co-operation and Development (OECD) Test Guidelines (TG) adopted the murine local lymph node assay (LLNA) and guinea pig maximization test (GPMT) as stand-alone skin sensitization test methods. However, unsaturated carbon-carbon double-bond and/or lipid acids afforded false-positive results more frequently in the LLNA compared to those in the GPMT and/or in human subjects. In the current study, oleic, linoleic, linolenic, undecylenic, fumaric, maleic, and succinic acid and squalene were tested in a modified LLNA with an elicitation phase (LLNA:DAE), and in a direct peptide reactivity assay (DPRA) to evaluate their skin-sensitizing potential. Oleic, linoleic, linolenic, undecylenic and maleic acid were positive in the LLNA:DAE, of which three, linoleic, linolenic, and maleic acid were positive in the DPRA. Furthermore, the results of the cross-sensitizing tests using four LLNA:DAE-positive chemicals were negative, indicating a chemical-specific elicitation response. In a previous report, the estimated concentration needed to produce a stimulation index of 3 (EC3) of linolenic acid, squalene, and maleic acid in the LLNA was undecylenic, and maleic acid had skin-sensitizing potential, and that the LLNA overestimated the skin-sensitizing potential compared to that estimated by the LLNA:DAE.

  18. Wireless Communications in Reverberant Environments

    Science.gov (United States)

    2015-01-01

    solutions exist which can be tailored to meet the needs nearly any wireless application. Some notable current solutions include USRPs [27] and GNURadio ...tailored to meet the needs nearly any wireless application. Some notable current solutions include USRPs [27] and GNURadio [28]. For this effort, the WARPv3...en.wikipedia.org/wiki/List of software-defined radios [27] “Ettus research.” [Online]. Available: http://www.ettus.com [28] “ Gnuradio .” [Online]. Available: http

  19. WIRELESS MINE WIDE TELECOMMUNICATIONS TECHNOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    Zvi H. Meiksin

    2002-04-01

    Two industrial prototype units for through-the-earth wireless communication were constructed and tested. Preparation for a temporary installation in NIOSH's Lake Lynn mine for the through-the-earth and the in-mine system were completed. Progress was made in the programming of the in-mine system to provide data communication. Work has begun to implement a wireless interface between equipment controllers and our in-mine system.

  20. WIRELESS MINE WIDE TELECOMMUNICATIONS TECHNOLOGY

    International Nuclear Information System (INIS)

    Zvi H. Meiksin

    2002-01-01

    Two industrial prototype units for through-the-earth wireless communication were constructed and tested. Preparation for a temporary installation in NIOSH's Lake Lynn mine for the through-the-earth and the in-mine system were completed. Progress was made in the programming of the in-mine system to provide data communication. Work has begun to implement a wireless interface between equipment controllers and our in-mine system

  1. Accuracy of an infrared marker-based patient positioning system (ExacTrac®) for stereotactic body radiotherapy in localizing the planned isocenter using fiducial markers

    Science.gov (United States)

    Montes-Rodríguez, María de los Ángeles; Hernández-Bojórquez, Mariana; Martínez-Gómez, Alma Angélica; Contreras-Pérez, Agustín; Negrete-Hernández, Ingrid Mireya; Hernández-Oviedo, Jorge Omar; Mitsoura, Eleni; Santiago-Concha, Bernardino Gabriel

    2014-11-01

    Stereotactic Body Radiation Therapy (SBRT) requires a controlled immobilization and position monitoring of patient and target. The purpose of this work is to analyze the performance of the imaging system ExacTrac® (ETX) using infrared and fiducial markers. Materials and methods: In order to assure the accuracy of isocenter localization, a Quality Assurance procedure was applied using an infrared marker-based positioning system. Scans were acquired of an inhouse-agar gel and solid water phantom with infrared spheres. In the inner part of the phantom, three reference markers were delineated as reference and one pellet was place internally; which was assigned as the isocenter. The iPlan® RT Dose treatment planning system. Images were exported to the ETX console. Images were acquired with the ETX to check the correctness of the isocenter placement. Adjustments were made in 6D the reference markers were used to fuse the images. Couch shifts were registered. The procedure was repeated for verification purposes. Results: The data recorded of the verifications in translational and rotational movements showed averaged 3D spatial uncertainties of 0.31 ± 0.42 mm respectively 0.82° ± 0.46° in the phantom and the first correction of these uncertainties were of 1.51 ± 1.14 mm respectively and 1.37° ± 0.61°. Conclusions: This study shows a high accuracy and repeatability in positioning the selected isocenter. The ETX-system for verifying the treatment isocenter position has the ability to monitor the tracing position of interest, making it possible to be used for SBRT positioning within uncertainty ≤1mm.

  2. Accuracy of an infrared marker-based patient positioning system (ExacTrac®) for stereotactic body radiotherapy in localizing the planned isocenter using fiducial markers

    Energy Technology Data Exchange (ETDEWEB)

    Montes-Rodríguez, María de los Ángeles, E-mail: angy24538@yahoo.com; Mitsoura, Eleni [Medical Physics Graduate Programme, Universidad Autónoma del Estado de México, Facultad de Medicina, Paseo Tollocan esquina Jesús Carranza Colonia Moderna de la Cruz, C.P. 50180, Toluca, Estado de México (Mexico); Hernández-Bojórquez, Mariana; Martínez-Gómez, Alma Angélica; Contreras-Pérez, Agustín; Negrete-Hernández, Ingrid Mireya; Hernández-Oviedo, Jorge Omar; Santiago-Concha, Bernardino Gabriel [Centro de Cáncer ABC, The American British Cowdray Medical Center I.A.P. (CMABC), Calle Sur 136, no. 116, Colonia las Américas, C.P. 01120, México, D.F. (Mexico)

    2014-11-07

    Stereotactic Body Radiation Therapy (SBRT) requires a controlled immobilization and position monitoring of patient and target. The purpose of this work is to analyze the performance of the imaging system ExacTrac® (ETX) using infrared and fiducial markers. Materials and methods: In order to assure the accuracy of isocenter localization, a Quality Assurance procedure was applied using an infrared marker-based positioning system. Scans were acquired of an inhouse-agar gel and solid water phantom with infrared spheres. In the inner part of the phantom, three reference markers were delineated as reference and one pellet was place internally; which was assigned as the isocenter. The iPlan® RT Dose treatment planning system. Images were exported to the ETX console. Images were acquired with the ETX to check the correctness of the isocenter placement. Adjustments were made in 6D the reference markers were used to fuse the images. Couch shifts were registered. The procedure was repeated for verification purposes. Results: The data recorded of the verifications in translational and rotational movements showed averaged 3D spatial uncertainties of 0.31 ± 0.42 mm respectively 0.82° ± 0.46° in the phantom and the first correction of these uncertainties were of 1.51 ± 1.14 mm respectively and 1.37° ± 0.61°. Conclusions: This study shows a high accuracy and repeatability in positioning the selected isocenter. The ETX-system for verifying the treatment isocenter position has the ability to monitor the tracing position of interest, making it possible to be used for SBRT positioning within uncertainty ≤1mm.

  3. A geometrical perspective on localization

    NARCIS (Netherlands)

    Dulman, S.O.; Baggio, A.; Havinga, Paul J.M.; Langendoen, K.G.; Zhang, Ying; Ye, Yinyu

    2008-01-01

    A large number of localization algorithms for wireless sensor networks (WSNs) are evaluated against the Cramer-Rao Bound (CRB) as an indicator of how good the algorithm performs. The CRB defines the lower bound on the precision of an unbiased localization estimator. The CRB concept, borrowed from

  4. Large-Scale Wireless Temperature Monitoring System for Liquefied Petroleum Gas Storage Tanks.

    Science.gov (United States)

    Fan, Guangwen; Shen, Yu; Hao, Xiaowei; Yuan, Zongming; Zhou, Zhi

    2015-09-18

    Temperature distribution is a critical indicator of the health condition for Liquefied Petroleum Gas (LPG) storage tanks. In this paper, we present a large-scale wireless temperature monitoring system to evaluate the safety of LPG storage tanks. The system includes wireless sensors networks, high temperature fiber-optic sensors, and monitoring software. Finally, a case study on real-world LPG storage tanks proves the feasibility of the system. The unique features of wireless transmission, automatic data acquisition and management, local and remote access make the developed system a good alternative for temperature monitoring of LPG storage tanks in practical applications.

  5. Large-Scale Wireless Temperature Monitoring System for Liquefied Petroleum Gas Storage Tanks

    Directory of Open Access Journals (Sweden)

    Guangwen Fan

    2015-09-01

    Full Text Available Temperature distribution is a critical indicator of the health condition for Liquefied Petroleum Gas (LPG storage tanks. In this paper, we present a large-scale wireless temperature monitoring system to evaluate the safety of LPG storage tanks. The system includes wireless sensors networks, high temperature fiber-optic sensors, and monitoring software. Finally, a case study on real-world LPG storage tanks proves the feasibility of the system. The unique features of wireless transmission, automatic data acquisition and management, local and remote access make the developed system a good alternative for temperature monitoring of LPG storage tanks in practical applications.

  6. STI tests and proportion of positive tests in female sex workers attending local public health departments in Germany in 2010/11.

    Science.gov (United States)

    Bremer, Viviane; Haar, Karin; Gassowski, Martyna; Hamouda, Osamah; Nielsen, Stine

    2016-11-21

    In Germany, local public health departments (LPHD) are required to offer low-threshold access to confidential counselling and testing for sexually transmitted infections (STI) for sex workers. We collected data from LPHD in Germany to estimate the number of performed STI tests and the proportion of positive STI tests among attending female sex workers (FSW) in order to formulate recommendations for improving STI testing and care for FSW in Germany. We recruited LPHD across Germany to collect aggregated data on attending FSW between January 2010 and March 2011. Baseline characteristics, the number of attending FSW, STI tests (HIV, Chlamydia trachomatis, Neisseria gonorrhoea, syphilis and Trichomonas vaginalis) and the number of positive results were provided by participating LPHD. We described the number of STI tests per FSW visit and the proportion of positive test results, including interquartile range (IQR). We tested whether baseline characteristics of LPHD were associated with the proportion of positive test results. Overall, 28 LPHD from 14 of the 16 federal states reported 9284 FSW visits over the study period, with a median of 188 FSW visits (IQR 45-440) per LPHD. Overall, a median of 77.1% (IQR 60.7-88.0) of visiting FSW received a test for Neisseria gonorrhoea, followed by HIV (66.0%, IQR 47.9-86.8), Chlamydia trachomatis (65.4%, IQR 50.7-83.6) and syphilis (61.6, IQR 48.6-78.6). In total, 22,914 STI tests were performed. The proportion of positive tests was 3.1% (IQR 1.3-4.8), with the highest proportion of positive tests for Chlamydia trachomatis (6.8%, IQR 2.5-10.4), followed by Neisseria gonorrhoea (3.2%, IQR 0.0-5.3), Trichomonas vaginalis (3.0%, IQR 0.0-15.4), syphilis (1.1%, IQR 0.0-1.3) and HIV (0.2%, IQR 0.0-0.4). The proportion of positive tests varied between 0 and 13.9% between LPHD, with a higher variation of proportion of positive tests in LPHD with a smaller number of reported STI tests. Participating LPHD varied in terms of performed STI

  7. Higher order mode spectra and the dependence of localized dipole modes on the transverse beam position in third harmonic superconducting cavities at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Pei [Manchester Univ. (United Kingdom); Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Baboi, Nicoleta [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Jones, Roger M. [The Cockcroft Institute, Daresbury (United Kingdom)

    2012-06-15

    An electron beam entering an accelerating cavity excites a wakefield. This wakefield can be decomposed into a series of multi-poles or modes. The dominant component of the transverse wakefield is dipole. This report summarizes the higher order mode (HOM) signals of the third harmonic cavities of FLASH measured at various stages: transmission measurements in the single cavity test stand at Fermilab, at CMTB (Cryo- Module Test Bench) and at FLASH, and beam-excited measurements at FLASH. Modes in the first two dipole bands and the fifth dipole band have been identified using a global Lorentzian fit technique. The beam-pipe modes at approximately 4 GHz and some modes in the fifth dipole band have been observed as localized modes, while the first two dipole bands, containing some strong coupling cavity modes, propagate. This report also presents the dependence of the localized dipole modes on the transverse beam position. Linear dependence for various modes has been observed. This makes them suitable for beam position diagnostics. These modes, together with some propagating, strong coupling modes, have been considered in the design of a dedicated electronics for beam diagnostics with HOMs for the third harmonic cavities.

  8. Higher order mode spectra and the dependence of localized dipole modes on the transverse beam position in third harmonic superconducting cavities at FLASH

    CERN Document Server

    Zhang, P; Jones, R M

    2012-01-01

    An electron beam entering an accelerating cavity excites a wakefield. This wakefield can be decomposed into a series of multi-poles or modes. The dominant component of the transverse wakefield is dipole. This report summarizes the higher order mode (HOM) signals of the third harmonic cavities of FLASH measured at various stages: transmission measurements in the single cavity test stand at Fermilab, at CMTB (Cryo-Module Test Bench) and at FLASH, and beam-excited measurements at FLASH. Modes in the first two dipole bands and the fifth dipole band have been identified using a global Lorentzian fit technique. The beam-pipe modes at approximately 4 GHz and some modes in the fifth dipole band have been observed as localized modes, while the first two dipole bands, containing some strong coupling cavity modes, propagate. This report also presents the dependence of the localized dipole modes on the transverse beam position. Linear dependence for various modes has been observed. This makes them suitable for beam posit...

  9. Fine processes of Nestin-GFP-positive radial glia-like stem cells in the adult dentate gyrus ensheathe local synapses and vasculature.

    Science.gov (United States)

    Moss, Jonathan; Gebara, Elias; Bushong, Eric A; Sánchez-Pascual, Irene; O'Laoi, Ruadhan; El M'Ghari, Imane; Kocher-Braissant, Jacqueline; Ellisman, Mark H; Toni, Nicolas

    2016-05-03

    Adult hippocampal neurogenesis relies on the activation of neural stem cells in the dentate gyrus, their division, and differentiation of their progeny into mature granule neurons. The complex morphology of radial glia-like (RGL) stem cells suggests that these cells establish numerous contacts with the cellular components of the neurogenic niche that may play a crucial role in the regulation of RGL stem cell activity. However, the morphology of RGL stem cells remains poorly described. Here, we used light microscopy and electron microscopy to examine Nestin-GFP transgenic mice and provide a detailed ultrastructural reconstruction analysis of Nestin-GFP-positive RGL cells of the dentate gyrus. We show that their primary processes follow a tortuous path from the subgranular zone through the granule cell layer and ensheathe local synapses and vasculature in the inner molecular layer. They share the ensheathing of synapses and vasculature with astrocytic processes and adhere to the adjacent processes of astrocytes. This extensive interaction of processes with their local environment could allow them to be uniquely receptive to signals from local neurons, glia, and vasculature, which may regulate their fate.

  10. Dimensionality reduction based on distance preservation to local mean for symmetric positive definite matrices and its application in brain-computer interfaces

    Science.gov (United States)

    Davoudi, Alireza; Shiry Ghidary, Saeed; Sadatnejad, Khadijeh

    2017-06-01

    Objective. In this paper, we propose a nonlinear dimensionality reduction algorithm for the manifold of symmetric positive definite (SPD) matrices that considers the geometry of SPD matrices and provides a low-dimensional representation of the manifold with high class discrimination in a supervised or unsupervised manner. Approach. The proposed algorithm tries to preserve the local structure of the data by preserving distances to local means (DPLM) and also provides an implicit projection matrix. DPLM is linear in terms of the number of training samples. Main results. We performed several experiments on the multi-class dataset IIa from BCI competition IV and two other datasets from BCI competition III including datasets IIIa and IVa. The results show that our approach as dimensionality reduction technique—leads to superior results in comparison with other competitors in the related literature because of its robustness against outliers and the way it preserves the local geometry of the data. Significance. The experiments confirm that the combination of DPLM with filter geodesic minimum distance to mean as the classifier leads to superior performance compared with the state of the art on brain-computer interface competition IV dataset IIa. Also the statistical analysis shows that our dimensionality reduction method performs significantly better than its competitors.

  11. Dimensionality reduction based on distance preservation to local mean for symmetric positive definite matrices and its application in brain-computer interfaces.

    Science.gov (United States)

    Davoudi, Alireza; Ghidary, Saeed Shiry; Sadatnejad, Khadijeh

    2017-06-01

    In this paper, we propose a nonlinear dimensionality reduction algorithm for the manifold of symmetric positive definite (SPD) matrices that considers the geometry of SPD matrices and provides a low-dimensional representation of the manifold with high class discrimination in a supervised or unsupervised manner. The proposed algorithm tries to preserve the local structure of the data by preserving distances to local means (DPLM) and also provides an implicit projection matrix. DPLM is linear in terms of the number of training samples. We performed several experiments on the multi-class dataset IIa from BCI competition IV and two other datasets from BCI competition III including datasets IIIa and IVa. The results show that our approach as dimensionality reduction technique-leads to superior results in comparison with other competitors in the related literature because of its robustness against outliers and the way it preserves the local geometry of the data. The experiments confirm that the combination of DPLM with filter geodesic minimum distance to mean as the classifier leads to superior performance compared with the state of the art on brain-computer interface competition IV dataset IIa. Also the statistical analysis shows that our dimensionality reduction method performs significantly better than its competitors.

  12. Fine processes of Nestin-GFP–positive radial glia-like stem cells in the adult dentate gyrus ensheathe local synapses and vasculature

    Science.gov (United States)

    Moss, Jonathan; Gebara, Elias; Sánchez-Pascual, Irene; O’Laoi, Ruadhan; El M’Ghari, Imane; Kocher-Braissant, Jacqueline; Ellisman, Mark H.; Toni, Nicolas

    2016-01-01

    Adult hippocampal neurogenesis relies on the activation of neural stem cells in the dentate gyrus, their division, and differentiation of their progeny into mature granule neurons. The complex morphology of radial glia-like (RGL) stem cells suggests that these cells establish numerous contacts with the cellular components of the neurogenic niche that may play a crucial role in the regulation of RGL stem cell activity. However, the morphology of RGL stem cells remains poorly described. Here, we used light microscopy and electron microscopy to examine Nestin-GFP transgenic mice and provide a detailed ultrastructural reconstruction analysis of Nestin-GFP–positive RGL cells of the dentate gyrus. We show that their primary processes follow a tortuous path from the subgranular zone through the granule cell layer and ensheathe local synapses and vasculature in the inner molecular layer. They share the ensheathing of synapses and vasculature with astrocytic processes and adhere to the adjacent processes of astrocytes. This extensive interaction of processes with their local environment could allow them to be uniquely receptive to signals from local neurons, glia, and vasculature, which may regulate their fate. PMID:27091993

  13. The role of wireless capsule endoscopy (WCE) in the detection of occult primary neuroendocrine tumors.

    Science.gov (United States)

    Furnari, Manuele; Buda, Andrea; Delconte, Gabriele; Citterio, Davide; Voiosu, Theodor; Ballardini, Giovanni; Cavallaro, Flaminia; Savarino, Edoardo; Mazzaferro, Vincenzo; Meroni, Emanuele

    2017-06-01

    Neuroendocrine tumors (NETs) are a heterogeneous group of neoplasms with unclear etiology that may show functioning or non-functioning features. Primary tumor localization often requires integrated imaging. The European Neuroendocrine Tumors Society (ENETS) guidelines proposed wireless-capsule endoscopy (WCE) as a possible diagnostic tool for NETs, if intestinal origin is suspected. However, its impact on therapeutic management is debated. We aimed to evaluate the yield of WCE in detecting intestinal primary tumors in patients showing liver NET metastases when first-line investigations are inconclusive. Twenty-four patients with a histological diagnosis of metastatic NET from liver biopsy and no evidence of primary lesions at first-line investigations were prospectively studied in an ENETS-certified tertiary care center. Wireless-capsule endoscopy was requested before explorative laparotomy and intra-operative ultrasound. The diagnostic yield of WCE was compared to the surgical exploration. Sixteen subjects underwent surgery; 11/16 had positive WCE identifying 16 bulging lesions. Mini-laparotomy found 13 NETs in 11/16 patients (9 small bowel, 3 pancreas, 1 bile ducts). Agreement between WCE and laparotomy was recorded in 9 patients (Sensitivity=75%; Specificity=37.5%; PPV=55%; NPV=60%). Correspondence assessed per-lesions produced similar results (Sensitivity=70%; Specificity=25%; PPV=44%; NPV=50%). No capsule retentions were recorded. Wireless-capsule endoscopy is not indicated as second-line investigation for patients with gastro-entero-pancreatic NETs. In the setting of a referral center, it might provide additional information when conventional investigations are inconclusive about the primary site.

  14. 76 FR 21742 - Wireless Telecommunications Bureau Extends Period for Filing Comments and Reply Comments on...

    Science.gov (United States)

    2011-04-18

    ...In this document, the Wireless Telecommunications Bureau extends the deadline for filing comments and reply comments in response to the Public Notice seeking comment on the December 3, 2010 petition for declaratory ruling (Petition) filed by CTIA--The Wireless Association (Petitioners). The Petitioners asked the Federal Communications Commission (Commission) to clarify ``the scope of Section 332(c)(3)(A)'s ban on state and local entry regulation.''

  15. Millimeter-wave Wireless LAN and its Extension toward 5G Heterogeneous Networks

    OpenAIRE

    Sakaguchi, Kei; Mohamed, Ehab Mahmoud; Kusano, Hideyuki; Mizukami, Makoto; Miyamoto, Shinichi; Rezagah, Roya; Takinami, Koji; Takahashi, Kazuaki; Shirakata, Naganori; Peng, Hailan; Yamamoto, Toshiaki; Namba, Shinobu

    2015-01-01

    Millimeter-wave (mmw) frequency bands, especially 60 GHz unlicensed band, are considered as a promising solution for gigabit short range wireless communication systems. IEEE standard 802.11ad, also known as WiGig, is standardized for the usage of the 60 GHz unlicensed band for wireless local area networks (WLANs). By using this mmw WLAN, multi-Gbps rate can be achieved to support bandwidth-intensive multimedia applications. Exhaustive search along with beamforming (BF) is usually used to over...

  16. Pilot Signal Design and Direct Ranging Methods for Radio Localization Using OFDM Systems

    DEFF Research Database (Denmark)

    Jing, Lishuai

    Having accurate localization capability is becoming important for existing and future terrestrial wireless communication systems, in particular for orthogonal frequency-division multiplexing (OFDM) systems, such as WiMAX, wireless local area network, long-term evolution (LTE) and its extension LTE......-Advanced. To obtain accurate position estimates, not only advanced estimation algorithms are needed but also the transmitted signals should be scrutinized. In this dissertation, we investigate how to design OFDM pilot signals and propose and evaluate high accuracy ranging techniques with tractable computational....... For scenarios where the number of path components is unknown and these components are not necessary separable, we propose a direct ranging technique using the received frequency-domain OFDM pilot signals. Compared to conventional (two-step) ranging methods, which estimate intermediate parameters...

  17. Wireless sensing and vibration control with increased redundancy and robustness design.

    Science.gov (United States)

    Li, Peng; Li, Luyu; Song, Gangbing; Yu, Yan

    2014-11-01

    Control systems with long distance sensor and actuator wiring have the problem of high system cost and increased sensor noise. Wireless sensor network (WSN)-based control systems are an alternative solution involving lower setup and maintenance costs and reduced sensor noise. However, WSN-based control systems also encounter problems such as possible data loss, irregular sampling periods (due to the uncertainty of the wireless channel), and the possibility of sensor breakdown (due to the increased complexity of the overall control system). In this paper, a wireless microcontroller-based control system is designed and implemented to wirelessly perform vibration control. The wireless microcontroller-based system is quite different from regular control systems due to its limited speed and computational power. Hardware, software, and control algorithm design are described in detail to demonstrate this prototype. Model and system state compensation is used in the wireless control system to solve the problems of data loss and sensor breakdown. A positive position feedback controller is used as the control law for the task of active vibration suppression. Both wired and wireless controllers are implemented. The results show that the WSN-based control system can be successfully used to suppress the vibration and produces resilient results in the presence of sensor failure.

  18. Traffic Profiling in Wireless Sensor Networks

    National Research Council Canada - National Science Library

    Kirykos, Georgios

    2006-01-01

    .... Wireless sensor networks pose unique challenges and limitations to the traditional schemes, which are used in the other wireless networks for security protection, and are due mainly to the increased...

  19. CMOS circuits for passive wireless microsystems

    CERN Document Server

    Yuan, Fei

    2011-01-01

    Here is a comprehensive examination of CMOS circuits for passive wireless microsystems. Covers design challenges, fundamental issues of ultra-low power wireless communications, radio-frequency power harvesting, and advanced design techniques, and more.

  20. Wireless Sensor Portal Technology, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Mobitrum Corporation has demonstrated the feasibility in the Phase I of " A Wireless Sensor Portal Technology" and proposes a Phase II effort to develop a wireless...

  1. Kali Linux wireless penetration testing beginner's guide

    CERN Document Server

    Ramachandran, Vivek

    2015-01-01

    If you are a security professional, pentester, or anyone interested in getting to grips with wireless penetration testing, this is the book for you. Some familiarity with Kali Linux and wireless concepts is beneficial.

  2. Wireless Inductive Power Device Suppresses Blade Vibrations

    Science.gov (United States)

    Morrison, Carlos R.; Provenza, Andrew J.; Choi, Benjamin B.; Bakhle, Milind A.; Min, James B.; Stefko, George L.; Duffy, Kirsten P.; Fougers, Alan J.

    2011-01-01

    Vibration in turbomachinery can cause blade failures and leads to the use of heavier, thicker blades that result in lower aerodynamic efficiency and increased noise. Metal and/or composite fatigue in the blades of jet engines has resulted in blade destruction and loss of lives. Techniques for suppressing low-frequency blade vibration, such as gtuned circuit resistive dissipation of vibratory energy, h or simply "passive damping," can require electronics incorporating coils of unwieldy dimensions and adding unwanted weight to the rotor. Other approaches, using vibration-dampening devices or damping material, could add undesirable weight to the blades or hub, making them less efficient. A wireless inductive power device (WIPD) was designed, fabricated, and developed for use in the NASA Glenn's "Dynamic Spin Rig" (DSR) facility. The DSR is used to simulate the functionality of turbomachinery. The relatively small and lightweight device [10 lb (approx.=4.5 kg)] replaces the existing venerable and bulky slip-ring. The goal is the eventual integration of this technology into actual turbomachinery such as jet engines or electric power generators, wherein the device will facilitate the suppression of potentially destructive vibrations in fan blades. This technology obviates slip rings, which require cooling and can prove unreliable or be problematic over time. The WIPD consists of two parts: a remote element, which is positioned on the rotor and provides up to 100 W of electrical power to thin, lightweight piezoelectric patches strategically placed on/in fan blades; and a stationary base unit that wirelessly communicates with the remote unit. The base unit supplies inductive power, and also acts as an input and output corridor for wireless measurement, and active control command to the remote unit. Efficient engine operation necessitates minimal disturbance to the gas flow across the turbine blades in any effort to moderate blade vibration. This innovation makes it

  3. Epitomized summarization of wireless capsule endoscopic videos for efficient visualization.

    Science.gov (United States)

    Chu, Xinqi; Poh, Chee Khun; Li, Liyuan; Chan, Kap Luk; Yan, Shuicheng; Shen, Weijia; Htwe, That Mon; Liu, Jiang; Lim, Joo Hwee; Ong, Eng Hui; Ho, Khek Yu

    2010-01-01

    A video recording of an examination by Wireless Capsule Endoscopy (WCE) may typically contain more than 55,000 video frames, which makes the manual visual screening by an experienced gastroenterologist a highly time-consuming task. In this paper, we propose a novel method of epitomized summarization of WCE videos for efficient visualization to a gastroenterologist. For each short sequence of a WCE video, an epitomized frame is generated. New constraints are introduced into the epitome formulation to achieve the necessary visual quality for manual examination, and an EM algorithm for learning the epitome is derived. First, the local context weights are introduced to generate the epitomized frame. The epitomized frame preserves the appearance of all the input patches from the frames of the short sequence. Furthermore, by introducing spatial distributions for semantic interpretation of image patches in our epitome formulation, we show that it also provides a framework to facilitate the semantic description of visual features to generate organized visual summarization of WCE video, where the patches in different positions correspond to different semantic information. Our experiments on real WCE videos show that, using epitomized summarization, the number of frames have to be examined by the gastroenterologist can be reduced to less than one-tenth of the original frames in the video.

  4. An Efficient Bypassing Void Routing Algorithm for Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Xunli Fan

    2015-01-01

    Full Text Available Since the sensor node’s distribution in a wireless sensor network (WSN is irregular, geographic routing protocols using the greedy algorithm can cause local minima problem. This problem may fail due to routing voids and lead to failure of data transmission. Based on the virtual coordinate mapping, this paper proposes an efficient bypassing void routing protocol to solve the control packet overhead and transmission delay in routing void of WSN, which is called EBVRPVCM. The basic idea is to transfer the random structure of void edge to a regular one through mapping the coordinates on a virtual circle. In EBVRPVCM, some strategies, executed in different regions, are selected through virtual coordinates to bypass routing void efficiently. The regular edge is established by coordinate mapping that can shorten the average routing path length and decrease the transmission delay. The virtual coordinate mapping is not affected by the real geographic node position, and the control packet overhead can be reduced accordingly. Compared with RGP and GPSR, simulation results demonstrate that EBVRPVCM can successfully find the shortest routing path with higher delivery ratio and less control packet overhead and energy consumption.

  5. 1st International Conference on Recent Cognizance in Wireless Communication & Image Processing

    CERN Document Server

    Srivastava, Vishnu; Singh, Ghanshyam; Bhatnagar, Deepak

    2016-01-01

    This volume comprises the proceedings of the International Conference on Recent Cognizance in Wireless Communication & Image Processing. It brings together content from academicians, researchers, and industry experts in areas of Wireless Communication and Image Processing. The volume provides a snapshot of current progress in computational creativity and a glimpse of future possibilities. The proceedings include two kinds of paper submissions: (i) regular papers addressing foundation issues, describing original research on creative systems development and modeling; and (ii) position papers describing work-in-progress or research directions for computational creativity. This work will be useful to professionals and researchers working in the core areas of wireless communications and image processing.

  6. STUDY & SURVEY ON WIRELESS CHARGING & TECHNOLOGY

    OpenAIRE

    Harshal Sharma*

    2016-01-01

    In the modern world, we have often heard a word- wireless charging technology. Actually what is it all about? So this paper is giving you the whole package about wireless charging technology. Wireless charging is a technology through which power is transmitted through an air gap to the electrical devices for the motive of replenishment of energy. At present wireless charging techniques and development of commercial products have provided a promise to address the energy bottleneck of portable ...

  7. Security Threats on Wireless Sensor Network Protocols

    OpenAIRE

    H. Gorine; M. Ramadan Elmezughi

    2016-01-01

    In this paper, we investigate security issues and challenges facing researchers in wireless sensor networks and countermeasures to resolve them. The broadcast nature of wireless communication makes Wireless Sensor Networks prone to various attacks. Due to resources limitation constraint in terms of limited energy, computation power and memory, security in wireless sensor networks creates different challenges than wired network security. We will discuss several attempts at addressing the issue...

  8. Proposal of Wireless Traffic Control Schemes for Wireless LANs

    Science.gov (United States)

    Hiraguri, Takefumi; Ichikawa, Takeo; Iizuka, Masataka; Kubota, Shuji

    This paper proposes two traffic control schemes to support the communication quality of multimedia streaming services such as VoIP and audio/video over IEEE 802.11 wireless LAN systems. The main features of the proposed scheme are bandwidth control for each flow of the multimedia streaming service and load balancing between access points (APs) of the wireless LAN by using information of data link, network and transport layers. The proposed schemes are implemented on a Linux machine which is called the wireless traffic controller (WTC). The WTC connects a high capacity backbone network and an access network to which the APs are attached. We evaluated the performance of the proposed WTC and confirmed that the communication quality of the multimedia streaming would be greatly improved by using this technique.

  9. Wireless Structural Sensing for Health Monitoring and Control Applications

    Science.gov (United States)

    Lynch, J. P.

    2003-12-01

    The economic and societal impact of civil structures under-performing during large earthquakes can be significant. While in recent years the structural engineering community has made great strides in advancing knowledge of structural behavior under extreme loads, a need still exists for the rapid assessment of structural performance during seismic events. Numerous options are commercially available to facility owners who wish to install a structural monitoring system within their structures. However, these structural monitoring systems are defined by their use of coaxial cables for the transfer of response measurements from sensors to centralized data servers. The installation and maintenance of cables within a civil structure often drive system costs high thereby preventing widespread industry adoption. In response to these limitations, the integration of information technologies such as wireless communications and microcontrollers have been explored for the creation of alternative structural monitoring systems defined by low installation costs and decentralized computational frameworks. In particular, a novel wireless structural monitoring system assembled from a dense network of inexpensive wireless sensing units has been designed and fabricated. The wireless sensing unit architecture consists of three functional components: a data acquisition interface for the collection of data from attached sensors, a computational core for data interrogation, and a wireless communication channel for the transfer of data to the sensor network. The use of wireless modems drastically reduces the efforts and costs of system installations rendering the technology attractive for widespread adoption in a broad class of civil structures. A second innovation of the system is the inclusion of computational power within each wireless sensing unit allowing for local execution of embedded engineering analyses. In particular, analyses for the detection of damage in structures (structural

  10. Techniques for Wireless Applications

    KAUST Repository

    Gaaloul, Fakhreddine

    2012-05-01

    Switching techniques have been first proposed as a spacial diversity techniques. These techniques have been shown to reduce considerably the processing load while letting multi-antenna systems achieve a specific target performance. In this thesis, we take a different look at the switching schemes by implementing them for different other wireless applications. More specifically, this thesis consists of three main parts, where the first part considers a multiuser environment and an adaptive scheduling algorithm based on the switching with post-selection scheme for statistically independent but non-identically distributed channel conditions. The performance of this switched based scheduler is investigated and a multitude of performance metrics are presented. In a second part, we propose and analyze the performance of three switched-based algorithms for interference reduction in the downlink of over-loaded femtocells. For instance, performance metrics are derived in closed-form and these metrics are used to compare these three proposed schemes. Finally in a third part, a switch based opportunistic channel access scheme is proposed for a cognitive radio system and its performance is analyzed in terms of two new proposed metrics namely the average cognitive radio access and the waiting time duration.

  11. Wideband Parameters Analysis and Validation for Indoor radio Channel at 60/70/80GHz for Gigabit Wireless Communication employing Isotropic, Horn and Omni directional Antenna

    OpenAIRE

    Affum, E.; Tchao, E. T.; Diawuo, K.; Agyekum, K.

    2013-01-01

    recently, applications of millimeter (mm) waves for high-speed broadband wireless local area network communication systems in indoor environment are increasingly gaining recognition as it provides gigabit-speed wireless communications with carrier-class performances over distances of a mile or more due to spectrum availability and wider bandwidth requirements. Collectively referred to as E-Band, the millimeter wave wireless technology present the potential to offer bandwidth delivery comparab...

  12. Advanced Wireless Sensor Nodes - MSFC

    Science.gov (United States)

    Varnavas, Kosta; Richeson, Jeff

    2017-01-01

    NASA field center Marshall Space Flight Center (Huntsville, AL), has invested in advanced wireless sensor technology development. Developments for a wireless microcontroller back-end were primarily focused on the commercial Synapse Wireless family of devices. These devices have many useful features for NASA applications, good characteristics and the ability to be programmed Over-The-Air (OTA). The effort has focused on two widely used sensor types, mechanical strain gauges and thermal sensors. Mechanical strain gauges are used extensively in NASA structural testing and even on vehicle instrumentation systems. Additionally, thermal monitoring with many types of sensors is extensively used. These thermal sensors include thermocouples of all types, resistive temperature devices (RTDs), diodes and other thermal sensor types. The wireless thermal board will accommodate all of these types of sensor inputs to an analog front end. The analog front end on each of the sensors interfaces to the Synapse wireless microcontroller, based on the Atmel Atmega128 device. Once the analog sensor output data is digitized by the onboard analog to digital converter (A/D), the data is available for analysis, computation or transmission. Various hardware features allow custom embedded software to manage battery power to enhance battery life. This technology development fits nicely into using numerous additional sensor front ends, including some of the low-cost printed circuit board capacitive moisture content sensors currently being developed at Auburn University.

  13. Wireless Communication Into MBB Heliostat Fields

    International Nuclear Information System (INIS)

    Garcia Navajas, G.

    2002-01-01

    Autonomous heliostats fields are a priority objective long time pursued by PSA. Removal of all the electric cables, trenches and related components will really mean an important cosi reduction in civil works and investment for future Solar Thermal Power Plants. Several previous developments have been required before making autonomous-heliostat fields an eventual reality. First, a new local control has been designed to adapt all heliostat components to work on 24Vdc supplied by a photovoltaic panel. Second, a specific radio modem has been designed for wireless Communications. In April 1999, the first autonomous heliostat was started up and main results were reported at the 10 SolarPACES International Symposium. The objective, fixed within the project SIREC fimded with theFEDER European Regional Development Program, has been to scale these concepts to a mini-field to demonstrate the feasibility of the wireless communication and operation with 20 MBB heliostats located at the North side of CRS facilities of PSA. A specific radio modem has been designed for this application thanks to the scientific cooperation agreement between the University of Almeria and CIEMAT. 50% of the heliostat field has been implemented with a commercial radio-modem and the other 50% with specific radio-modems to compare the performance and capabilities. The capacities of both systems will be analysed and the main data obtained from the test campaign carried out, will be showed. (Author) 12 refs

  14. Automated alignment system for optical wireless communication systems using image recognition.

    Science.gov (United States)

    Brandl, Paul; Weiss, Alexander; Zimmermann, Horst

    2014-07-01

    In this Letter, we describe the realization of a tracked line-of-sight optical wireless communication system for indoor data distribution. We built a laser-based transmitter with adaptive focus and ray steering by a microelectromechanical systems mirror. To execute the alignment procedure, we used a CMOS image sensor at the transmitter side and developed an algorithm for image recognition to localize the receiver's position. The receiver is based on a self-developed optoelectronic integrated chip with low requirements on the receiver optics to make the system economically attractive. With this system, we were able to set up the communication link automatically without any back channel and to perform error-free (bit error rate <10⁻⁹) data transmission over a distance of 3.5 m with a data rate of 3 Gbit/s.

  15. WIRELESS FIDELITY (Wi-Fi) BROADBAND NETWORK ...

    African Journals Online (AJOL)

    ES Obe

    categorized into two types: fixed and mobile wireless. The broadband fixed wireless network technologies .... 3.0 WIRELESS FIDELITYF (Wi-Fi). NETWORK IMPLEMENTATION. A Wi-Fi enabled device such as a PC, game .... Amateur radio, video senders, and cordless phones, can cause significant additional interference.

  16. WirelessHART modeling and performance evaluation

    NARCIS (Netherlands)

    Remke, Anne Katharina Ingrid; Wu, Xian

    2013-01-01

    In process industries wired supervisory and control networks are more and more replaced by wireless systems. Wireless communication inevitably introduces time delays and message losses, which may degrade the system reliability and performance. WirelessHART, as the first international standard for

  17. Local SAR enhancements in anatomically correct children and adult models as a function of position within 1.5 T MR body coil.

    Science.gov (United States)

    Murbach, Manuel; Cabot, Eugenia; Neufeld, Esra; Gosselin, Marie-Christine; Christ, Andreas; Pruessmann, Klaas P; Kuster, Niels

    2011-12-01

    Usage of magnetic resonance imaging (MRI) is continuously increasing due to its excellent soft-tissue contrast and improving diagnostic values. MRI also has the advantage that it operates without ionizing radiation. The main safety concerns are torque, acceleration by the static field, nerve stimulation by the gradient fields, and tissue heating by the radio-frequency (RF) fields. This paper investigates if children and fetuses are at higher risks than adults when the current RF regulations are applied. We analyzed and compared local absorption hotspots, i.e., the peak spatial specific absorption rate averaged over any 10 g (psSAR10g) for five adults, three children of ages 5, 11 and 14 years, and 1 pregnant female (36 weeks' gestation) in 10 different Z-positions (head to calves). In the First Level Operating Mode (4 W/kg whole-body averaged exposure), the psSAR10g values found for adults were as large as 60 W/kg in the trunk and 104 W/kg in the extremities. The corresponding values for children were 43 and 58 W/kg, respectively, and 14 W/kg for the unborn child. Modeling of worst case anatomical RF loops can substantially increase the psSAR10g values, i.e., by factor >2. The results suggest that local exposure for children and fetuses is smaller than for adults (15-75%), i.e., no special considerations for children and the unborn child are needed regarding psSAR10g due to RF. However, the local thermal load of the unborn may be significantly increased due to the high exposure average (up to 4 W/kg) of the non-perfused amniotic fluid. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Multi-technology positioning

    CERN Document Server

    Lohan, Elena-Simona; Wymeersch, Henk; Seco-Granados, Gonzalo; Nykänen, Ossi

    2017-01-01

    This book provides an overview of positioning technologies, applications and services in a format accessible to a wide variety of readers. Readers who have always wanted to understand how satellite-based positioning, wireless network positioning, inertial navigation, and their combinations work will find great value in this book. Readers will also learn about the advantages and disadvantages of different positioning methods, their limitations and challenges. Cognitive positioning, adding the brain to determine which technologies to use at device runtime, is introduced as well. Coverage also includes the use of position information for Location Based Services (LBS), as well as context-aware positioning services, designed for better user experience. • Brings understanding of positioning technology to readers from a variety of disciplines • Reviews multiple techniques, providing insight on the pros, cons and challenges related to each • Designed to be a tutorial on basic principles, avoiding unnecessary de...

  19. A State-of-the-Art Survey of Indoor Positioning and Navigation Systems and Technologies

    Directory of Open Access Journals (Sweden)

    Wilson Sakpere

    2017-12-01

    Full Text Available The research and use of positioning and navigation technologies outdoors has seen a steady and exponential growth. Based on this success, there have been attempts to implement these technologies indoors, leading to numerous studies. Most of the algorithms, techniques and technologies used have been implemented outdoors. However, how they fare indoors is different altogether. Thus, several technologies have been proposed and implemented to improve positioning and navigation indoors. Among them are Infrared (IR, Ultrasound, Audible Sound, Magnetic, Optical and Vision, Radio Frequency (RF, Visible Light, Pedestrian Dead Reckoning (PDR/Inertial Navigation System (INS and Hybrid. The RF technologies include Bluetooth, Ultra-wideband (UWB, Wireless Sensor Network (WSN, Wireless Local Area Network (WLAN, Radio-Frequency Identification (RFID and Near Field Communication (NFC. In addition, positioning techniques applied in indoor positioning systems include the signal properties and positioning algorithms. The prevalent signal properties are Angle of Arrival (AOA, Time of Arrival (TOA, Time Difference of Arrival (TDOA and Received Signal Strength Indication (RSSI, while the positioning algorithms are Triangulation, Trilateration, Proximity and Scene Analysis/ Fingerprinting. This paper presents a state-of-the-art survey of indoor positioning and navigation systems and technologies, and their use in various scenarios. It analyses distinct positioning technology metrics such as accuracy, complexity, cost, privacy, scalability and usability. This paper has profound implications for future studies of positioning and navigation.

  20. Wireless device monitoring systems and monitoring devices, and associated methods

    Science.gov (United States)

    McCown, Steven H; Derr, Kurt W; Rohde, Kenneth W

    2014-05-27

    Wireless device monitoring systems and monitoring devices include a communications module for receiving wireless communications of a wireless device. Processing circuitry is coupled with the communications module and configured to process the wireless communications to determine whether the wireless device is authorized or unauthorized to be present at the monitored area based on identification information of the wireless device. Methods of monitoring for the presence and identity of wireless devices are also provided.