WorldWideScience

Sample records for networked radar environment

  1. Cramer-Rao Lower Bound Evaluation for Linear Frequency Modulation Based Active Radar Networks Operating in a Rice Fading Environment

    Directory of Open Access Journals (Sweden)

    Chenguang Shi

    2016-12-01

    Full Text Available This paper investigates the joint target parameter (delay and Doppler estimation performance of linear frequency modulation (LFM-based radar networks in a Rice fading environment. The active radar networks are composed of multiple radar transmitters and multichannel receivers placed on moving platforms. First, the log-likelihood function of the received signal for a Rician target is derived, where the received signal scattered off the target comprises of dominant scatterer (DS component and weak isotropic scatterers (WIS components. Then, the analytically closed-form expressions of the Cramer-Rao lower bounds (CRLBs on the Cartesian coordinates of target position and velocity are calculated, which can be adopted as a performance metric to access the target parameter estimation accuracy for LFM-based radar network systems in a Rice fading environment. It is found that the cumulative Fisher information matrix (FIM is a linear combination of both DS component and WIS components, and it also demonstrates that the joint CRLB is a function of signal-to-noise ratio (SNR, target’s radar cross section (RCS and transmitted waveform parameters, as well as the relative geometry between the target and the radar network architectures. Finally, numerical results are provided to indicate that the joint target parameter estimation performance of active radar networks can be significantly improved with the exploitation of DS component.

  2. Coordinated Radar Resource Management for Networked Phased Array Radars

    Science.gov (United States)

    2014-12-01

    computed, and the detection of a target is determined based on a Monte Carlo test. For each successful target confirmation, a measurement report is...detection based on Monte Carlo test • add appropriate random perturbations to detec- tion measurements Radar Targets Environment Input Parameters... Fuente and J.R. Casar-Corredera. Optimal radar pulse scheduling using a neural network. In IEEE Int. Conf. Neural Networks, volume 7, pages 4558–4591

  3. Radar Methods in Urban Environments

    Science.gov (United States)

    2016-10-26

    AFRL-AFOSR-VA-TR-2016-0344 Radar Methods in Urban Environments Arye Nehorai WASHINGTON UNIVERSITY THE Final Report 10/26/2016 DISTRIBUTION A...Methods in Urban Environments 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA9550-11-1-0210 5c.  PROGRAM ELEMENT NUMBER 61102F 6. AUTHOR(S) Arye Nehorai 5d...Methods in Urban Environments Grant No. FA9550-11-1-0210 Final Report August 2011 – July 2016 Arye Nehorai Department of Electrical and Systems

  4. Multitarget tracking in cluttered environment for a multistatic passive radar system under the DAB/DVB network

    Science.gov (United States)

    Shi, Yi Fang; Park, Seung Hyo; Song, Taek Lyul

    2017-12-01

    The target tracking using multistatic passive radar in a digital audio/video broadcast (DAB/DVB) network with illuminators of opportunity faces two main challenges: the first challenge is that one has to solve the measurement-to-illuminator association ambiguity in addition to the conventional association ambiguity between the measurements and targets, which introduces a significantly complex three-dimensional (3-D) data association problem among the target-measurement illuminator, this is because all the illuminators transmit the same carrier frequency signals and signals transmitted by different illuminators but reflected via the same target become indistinguishable; the other challenge is that only the bistatic range and range-rate measurements are available while the angle information is unavailable or of very poor quality. In this paper, the authors propose a new target tracking algorithm directly in three-dimensional (3-D) Cartesian coordinates with the capability of track management using the probability of target existence as a track quality measure. The proposed algorithm is termed sequential processing-joint integrated probabilistic data association (SP-JIPDA), which applies the modified sequential processing technique to resolve the additional association ambiguity between measurements and illuminators. The SP-JIPDA algorithm sequentially operates the JIPDA tracker to update each track for each illuminator with all the measurements in the common measurement set at each time. For reasons of fair comparison, the existing modified joint probabilistic data association (MJPDA) algorithm that addresses the 3-D data association problem via "supertargets" using gate grouping and provides tracks directly in 3-D Cartesian coordinates, is enhanced by incorporating the probability of target existence as an effective track quality measure for track management. Both algorithms deal with nonlinear observations using the extended Kalman filtering. A simulation study is

  5. Ultra-wideband radar sensors and networks

    Science.gov (United States)

    Leach, Jr., Richard R; Nekoogar, Faranak; Haugen, Peter C

    2013-08-06

    Ultra wideband radar motion sensors strategically placed in an area of interest communicate with a wireless ad hoc network to provide remote area surveillance. Swept range impulse radar and a heart and respiration monitor combined with the motion sensor further improves discrimination.

  6. Radar Training Facility Local Area Network -

    Data.gov (United States)

    Department of Transportation — The RTF LAN system provides a progressive training environment for initial and refresher radar training qualification for new and re-hired FAA employees. Its purpose...

  7. Radar Target Classification Using Neural Network and Median Filter

    OpenAIRE

    J. Kurty; Matousek, Z.

    2001-01-01

    The paper deals with Radar Target Classification based on the use of a neural network. A radar signal was acquired from the output of a J frequency band noncoherent radar. We applied the three layer feed forward neural network using the backpropagation learning algorithm. We defined classes of radar targets and designated each of them by its number. Our classification process resulted in the number of a radar target class, which the radar target belongs to.

  8. Radar Target Classification Using Neural Network and Median Filter

    Directory of Open Access Journals (Sweden)

    J. Kurty

    2001-09-01

    Full Text Available The paper deals with Radar Target Classification based on the use ofa neural network. A radar signal was acquired from the output of a Jfrequency band noncoherent radar. We applied the three layer feedforward neural network using the backpropagation learning algorithm. Wedefined classes of radar targets and designated each of them by itsnumber. Our classification process resulted in the number of a radartarget class, which the radar target belongs to.

  9. Radar operation in a hostile electromagnetic environment

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2014-03-01

    Radar ISR does not always involve cooperative or even friendly targets. An adversary has numerous techniques available to him to counter the effectiveness of a radar ISR sensor. These generally fall under the banner of jamming, spoofing, or otherwise interfering with the EM signals required by the radar sensor. Consequently mitigation techniques are prudent to retain efficacy of the radar sensor. We discuss in general terms a number of mitigation techniques.

  10. Mutual information-based LPI optimisation for radar network

    Science.gov (United States)

    Shi, Chenguang; Zhou, Jianjiang; Wang, Fei; Chen, Jun

    2015-07-01

    Radar network can offer significant performance improvement for target detection and information extraction employing spatial diversity. For a fixed number of radars, the achievable mutual information (MI) for estimating the target parameters may extend beyond a predefined threshold with full power transmission. In this paper, an effective low probability of intercept (LPI) optimisation algorithm is presented to improve LPI performance for radar network. Based on radar network system model, we first provide Schleher intercept factor for radar network as an optimisation metric for LPI performance. Then, a novel LPI optimisation algorithm is presented, where for a predefined MI threshold, Schleher intercept factor for radar network is minimised by optimising the transmission power allocation among radars in the network such that the enhanced LPI performance for radar network can be achieved. The genetic algorithm based on nonlinear programming (GA-NP) is employed to solve the resulting nonconvex and nonlinear optimisation problem. Some simulations demonstrate that the proposed algorithm is valuable and effective to improve the LPI performance for radar network.

  11. Fuzzy Chance-constrained Programming Based Security Information Optimization for Low Probability of Identification Enhancement in Radar Network Systems

    Directory of Open Access Journals (Sweden)

    C. G. Shi

    2015-04-01

    Full Text Available In this paper, the problem of low probability of identification (LPID improvement for radar network systems is investigated. Firstly, the security information is derived to evaluate the LPID performance for radar network. Then, without any prior knowledge of hostile intercept receiver, a novel fuzzy chance-constrained programming (FCCP based security information optimization scheme is presented to achieve enhanced LPID performance in radar network systems, which focuses on minimizing the achievable mutual information (MI at interceptor, while the attainable MI outage probability at radar network is enforced to be greater than a specified confidence level. Regarding to the complexity and uncertainty of electromagnetic environment in the modern battlefield, the trapezoidal fuzzy number is used to describe the threshold of achievable MI at radar network based on the credibility theory. Finally, the FCCP model is transformed to a crisp equivalent form with the property of trapezoidal fuzzy number. Numerical simulation results demonstrating the performance of the proposed strategy are provided.

  12. Flood Monitoring using X-band Dual-polarization Radar Network

    Science.gov (United States)

    Chandrasekar, V.; Wang, Y.; Maki, M.; Nakane, K.

    2009-09-01

    A dense weather radar network is an emerging concept advanced by the Center for Collaborative Adaptive Sensing of the Atmosphere (CASA). Using multiple radars observing over a common will create different data outcomes depending on the characteristics of the radar units employed and the network topology. To define this a general framework is developed to describe the radar network space, and formulations are obtained that can be used for weather radar network characterization. Current weather radar surveillance networks are based upon conventional sensing paradigm of widely-separated, standalone sensing systems using long range radars that operate at wavelengths in 5-10 cm range. Such configuration has limited capability to observe close to the surface of the earth because of the earth's curvature but also has poorer resolution at far ranges. The dense network radar system, observes and measures weather phenomenon such as rainfall and severe weather close to the ground at higher spatial and temporal resolution compared to the current paradigm. In addition the dense network paradigm also is easily adaptable to complex terrain. Flooding is one of the most common natural hazards in the world. Especially, excessive development decreases the response time of urban watersheds and complex terrain to rainfall and increases the chance of localized flooding events over a small spatial domain. Successful monitoring of urban floods requires high spatiotemporal resolution, accurate precipitation estimation because of the rapid flood response as well as the complex hydrologic and hydraulic characteristics in an urban environment. This paper reviews various aspects in radar rainfall mapping in urban coverage using dense X-band dual-polarization radar networks. By reducing the maximum range and operating at X-band, one can ensure good azimuthal resolution with a small-size antenna and keep the radar beam closer to the ground. The networked topology helps to achieve satisfactory

  13. Road Network Conflation Based on Radar Tracks

    Science.gov (United States)

    2014-04-01

    by the National Imagery and Mapping Agency ( NIMA ) as well as the United States Geological Survey (USGS), the two most com- mon sources of such maps...Likelihood Estimator NIMA National Imagery and Mapping Agency SAR Synthetic Aperture Radar STAP Space-Time Adaptive Processing USGS United States Geological Survey 27 Approved for Public Release; Distribution Unlimited.

  14. Sparse Representation Based Range-Doppler Processing for Integrated OFDM Radar-Communication Networks

    Directory of Open Access Journals (Sweden)

    Bo Kong

    2017-01-01

    Full Text Available In an integrated radar-communication network, multiuser access techniques with minimal performance degradation and without range-Doppler ambiguities are required, especially in a dense user environment. In this paper, a multiuser access scheme with random subcarrier allocation mechanism is proposed for orthogonal frequency division multiplexing (OFDM based integrated radar-communication networks. The expression of modulation Symbol-Domain method combined with sparse representation (SR for range-Doppler estimation is introduced and a parallel reconstruction algorithm is employed. The radar target detection performance is improved with less spectrum occupation. Additionally, a Doppler frequency detector is exploited to decrease the computational complexity. Numerical simulations show that the proposed method outperforms the traditional modulation Symbol-Domain method under ideal and realistic nonideal scenarios.

  15. Interval algebra - an effective means of scheduling surveillance radar networks

    CSIR Research Space (South Africa)

    Focke, RW

    2015-05-01

    Full Text Available Interval Algebra provides an effective means to schedule surveillance radar networks, as it is a temporal ordering constraint language. Thus it provides a solution to a part of resource management, which is included in the revised Data Fusion...

  16. Oblique Projection Polarization Filtering-Based Interference Suppressions for Radar Sensor Networks

    Directory of Open Access Journals (Sweden)

    Cao Bin

    2010-01-01

    Full Text Available The interferences coming from the radar members degrade the detection and recognition performance of the radar sensor networks (RSNs if the waveforms of the radar members are nonorthogonal. In this paper, we analyze the interferences by exploring the polarization information of the electromagnetic (EM waves. Then, we propose the oblique projection polarization filtering- (OPPF- based scheme to suppress the interferences while keeping the amplitude and phase of its own return in RSNs, even if the polarized states of the radar members are not orthogonal. We consider the cooperative RSNs environment where the polarization information of each radar member is known to all. The proposed method uses all radar members' polarization information to establish the corresponding filtering operator. The Doppler-shift and its uncertainty are independent of the polarization information, which contributes that the interferences can be suppressed without the utilization of the spatial, the temporal, the frequency, the time-delay and the Doppler-shift information. Theoretical analysis and the mathematical deduction show that the proposed scheme is a valid and simple implementation. Simulation results also demonstrate that this method can obtain a good filtering performance when dealing with the problem of interference suppressions for RSNs.

  17. Passive Synthetic Aperture Radar Imaging Using Commercial OFDM Communication Networks

    Science.gov (United States)

    2012-09-13

    imaging area. 24 Falcone and Colone recently presented passive radar work using the 802.11 OFDM WiFi signal [31]. The study demonstrates the practical...φR is 4.3 degrees at both aperture ends. The array is radiated with the generic OFDM pulse. The OFDM symbols use 112 Figure 67. PFA SAR image using a...OFDM WiFi -based passive bistatic radar”. Radar Conference, 2010 IEEE, 516–521. 2010. [32] Flood, J.E. Telecommunication Networks, 2ed. The

  18. GPM GROUND VALIDATION ENVIRONMENT CANADA (EC) MICRO RAIN RADAR (MRR) GCPEX V2

    Data.gov (United States)

    National Aeronautics and Space Administration — The GPM Ground Validation Environment Canada (EC) Micro Rain Radar (MRR) GCPEx V2 dataset was collected from the Micro Rain Radar (MRR) during the GPM Cold-season...

  19. Social Networks and the Environment

    OpenAIRE

    Julio Videras

    2013-01-01

    This review discusses empirical research on social networks and the environment; it summarizes findings from representative studies and the conceptual frameworks social scientists use to examine the role of social networks. The article presents basic concepts in social network analysis, summarizes common challenges of empirical research on social networks, and outlines areas for future research. Finally, the article discusses the normative and positive meanings of social networks.

  20. Networking for the Environment

    DEFF Research Database (Denmark)

    Dickel, Petra; Hörisch, Jacob; Ritter, Thomas

    2018-01-01

    from 248 technology-based start-ups shows that those firms with a strong external environmental orientation have significantly higher networking frequencies and build larger networks. Conversely, a strong internal environmental orientation is linked to smaller networks. Thus, the results highlight......Although the public debate on the environmental orientation of firms has intensified, there is a lack of understanding about the consequences of that orientation, especially in terms of its impact on firms' networking behavior. In order to fill this gap, this paper analyzes the impact of external...... and internal environmental orientation on start-ups’ network characteristics, because networks are both vital for the success of start-ups and resource demanding. More specifically, the effects of environmental orientation on networking frequency and network size among start-ups are analyzed. Empirical data...

  1. Weather Radar Estimations Feeding an Artificial Neural Network Model Weather Radar Estimations Feeding an Artificial Neural Network Model

    Directory of Open Access Journals (Sweden)

    Dawei Han

    2012-02-01

    Full Text Available The application of ANNs (Artifi cial Neural Networks has been studied by many researchers in modelling rainfall runoff processes. However, the work so far has been focused on the rainfall data from traditional raingauges. Weather radar is a modern technology which could provide high resolution rainfall in time and space. In this study, a comparison in rainfall runoff modelling between the raingauge and weather radar has been carried out. The data were collected from Brue catchment in Southwest of England, with 49 raingauges covering 136 km2 and two C-band weather radars. This raingauge network is extremely dense (for research purposes and does not represent the usual raingauge density in operational flood forecasting systems. The ANN models were set up with both lumped and spatial rainfall input. The results showed that raingauge data outperformed radar data in all the events tested, regardless of the lumped and spatial input. La aplicación de Redes Neuronales Artificiales (RNA en el modelado de lluvia-flujo ha sido estudiada ampliamente. Sin embargo, hasta ahora se han utilizado datos provenientes de pluviómetros tradicionales. Los radares meteorológicos son una tecnología moderna que puede proveer datos de lluvia de alta resolución en tiempo y espacio. Este es un trabajo de comparación en el modelado lluvia-flujo entre pluviómetros y radares meteorológicos. Los datos provienen de la cuenca del río Brue en el suroeste de Inglaterra, con 49 pluviómetros cubriendo 136 km2 y dos radares meteorológicos en la banda C. Esta red de pluviómetros es extremadamente densa (para investigación y no representa la densidad usual en sistemas de predicción de inundaciones. Los modelos de RNA fueron implementados con datos de entrada de lluvia tanto espaciados como no distribuidos. Los resultados muestran que los datos de los pluviómetros fueron mejores que los datos de los radares en todos los eventos probados.

  2. NASA's unique networking environment

    Science.gov (United States)

    Johnson, Marjory J.

    1988-01-01

    Networking is an infrastructure technology; it is a tool for NASA to support its space and aeronautics missions. Some of NASA's networking problems are shared by the commercial and/or military communities, and can be solved by working with these communities. However, some of NASA's networking problems are unique and will not be addressed by these other communities. Individual characteristics of NASA's space-mission networking enviroment are examined, the combination of all these characteristics that distinguish NASA's networking systems from either commercial or military systems is explained, and some research areas that are important for NASA to pursue are outlined.

  3. Environment Aware Cellular Networks

    KAUST Repository

    Ghazzai, Hakim

    2015-02-01

    The unprecedented rise of mobile user demand over the years have led to an enormous growth of the energy consumption of wireless networks as well as the greenhouse gas emissions which are estimated currently to be around 70 million tons per year. This significant growth of energy consumption impels network companies to pay huge bills which represent around half of their operating expenditures. Therefore, many service providers, including mobile operators, are looking for new and modern green solutions to help reduce their expenses as well as the level of their CO2 emissions. Base stations are the most power greedy element in cellular networks: they drain around 80% of the total network energy consumption even during low traffic periods. Thus, there is a growing need to develop more energy-efficient techniques to enhance the green performance of future 4G/5G cellular networks. Due to the problem of traffic load fluctuations in cellular networks during different periods of the day and between different areas (shopping or business districts and residential areas), the base station sleeping strategy has been one of the main popular research topics in green communications. In this presentation, we present several practical green techniques that provide significant gains for mobile operators. Indeed, combined with the base station sleeping strategy, these techniques achieve not only a minimization of the fossil fuel consumption but also an enhancement of mobile operator profits. We start with an optimized cell planning method that considers varying spatial and temporal user densities. We then use the optimal transport theory in order to define the cell boundaries such that the network total transmit power is reduced. Afterwards, we exploit the features of the modern electrical grid, the smart grid, as a new tool of power management for cellular networks and we optimize the energy procurement from multiple energy retailers characterized by different prices and pollutant

  4. National High Frequency Radar Network (hfrnet) and Pacific Research Efforts

    Science.gov (United States)

    Hazard, L.; Terrill, E. J.; Cook, T.; de Paolo, T.; Otero, M. P.; Rogowski, P.; Schramek, T. A.

    2016-12-01

    The U.S. High Frequency Radar Network (HFRNet) has been in operation for over ten years with representation from 31 organizations spanning academic institutions, state and local government agencies, and private organizations. HFRNet currently holds a collection from over 130 radar installations totaling over 10 million records of surface ocean velocity measurements. HFRNet is a primary example of inter-agency and inter-institutional partnerships for improving oceanographic research and operations. HF radar derived surface currents have been used in several societal applications including coastal search and rescue, oil spill response, water quality monitoring and marine navigation. Central to the operational success of the large scale network is an efficient data management, storage, access, and delivery system. The networking of surface current mapping systems is characterized by a tiered structure that extends from the individual field installations to local regional operations maintaining multiple sites and on to centralized locations aggregating data from all regions. The data system development effort focuses on building robust data communications from remote field locations (sites) for ingestion into the data system via data on-ramps (Portals or Site Aggregators) to centralized data repositories (Nodes). Centralized surface current data enables the aggregation of national surface current grids and allows for ingestion into displays, management tools, and models. The Coastal Observing Research and Development Center has been involved in international relationships and research in the Philippines, Palau, and Vietnam. CORDC extends this IT architecture of surface current mapping data systems leveraging existing developments and furthering standardization of data services for seamless integration of higher level applications. Collaborations include the Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA), The Coral Reef Research

  5. Radar network communication through sensing of frequency hopping

    Science.gov (United States)

    Dowla, Farid; Nekoogar, Faranak

    2013-05-28

    In one embodiment, a radar communication system includes a plurality of radars having a communication range and being capable of operating at a sensing frequency and a reporting frequency, wherein the reporting frequency is different than the sensing frequency, each radar is adapted for operating at the sensing frequency until an event is detected, each radar in the plurality of radars has an identification/location frequency for reporting information different from the sensing frequency, a first radar of the radars which senses the event sends a reporting frequency corresponding to its identification/location frequency when the event is detected, and all other radars in the plurality of radars switch their reporting frequencies to match the reporting frequency of the first radar upon detecting the reporting frequency switch of a radar within the communication range. In another embodiment, a method is presented for communicating information in a radar system.

  6. RNEDE: Resilient Network Design Environment

    Energy Technology Data Exchange (ETDEWEB)

    Venkat Venkatasubramanian, Tanu Malik, Arun Giridh; Craig Rieger; Keith Daum; Miles McQueen

    2010-08-01

    Modern living is more and more dependent on the intricate web of critical infrastructure systems. The failure or damage of such systems can cause huge disruptions. Traditional design of this web of critical infrastructure systems was based on the principles of functionality and reliability. However, it is increasingly being realized that such design objectives are not sufficient. Threats, disruptions and faults often compromise the network, taking away the benefits of an efficient and reliable design. Thus, traditional network design parameters must be combined with self-healing mechanisms to obtain a resilient design of the network. In this paper, we present RNEDEa resilient network design environment that that not only optimizes the network for performance but tolerates fluctuations in its structure that result from external threats and disruptions. The environment evaluates a set of remedial actions to bring a compromised network to an optimal level of functionality. The environment includes a visualizer that enables the network administrator to be aware of the current state of the network and the suggested remedial actions at all times.

  7. Road safety alerting system with radar and GPS cooperation in a VANET environment

    Science.gov (United States)

    Santamaria, Amilcare Francesco; Sottile, Cesare; De Rango, Floriano; Voznak, Miroslav

    2014-05-01

    New applications in wireless environments are increasing and keeping even more interests from the developer companies and researchers. In particular, in these last few years the government and institutional organization for road safety spent a lot of resources and money to promote Vehicular Ad-Hoc Network (VANET) technology, also car manufactures are giving a lot of contributions on this field as well. In our paper, we propose an innovative system to increase road safety, matching the requests of the market allowing a cooperation between on-board devices. The vehicles are equipped with On Board Unit (OBU) and On Board Radar Unit (OBRU), which can spread alerting messages around the network regarding warning and dangerous situations exploiting IEEE802.llp standard. Vehicles move along roads observing the environment, traffic and road conditions, and vehicles parameters as well. These information can be elaborated and shared between neighbors, Road Side Unit (RSU)s and, of course, with Internet, allowing inter-system communications exploiting an Road Traffic Manager (RTM). Radar systems task it the detection of the environment in order to increase the knowledge of current conditions of the roads, for example it is important to identify obstacles, road accidents, dangerous situations and so on. Once detected exploiting onboard devices, such as Global Position System (GPS) receiver it is possible to know the exact location of the caught event and after a data elaboration the information is spread along the network. Once the drivers are advised, they can make some precautionary actions such as reduction of traveling speed or modification of current road path. In this work the routing algorithms, which have the main goal to rapidly disseminate information, are also been investigated.

  8. Joint Optimization of Receiver Placement and Illuminator Selection for a Multiband Passive Radar Network.

    Science.gov (United States)

    Xie, Rui; Wan, Xianrong; Hong, Sheng; Yi, Jianxin

    2017-06-14

    The performance of a passive radar network can be greatly improved by an optimal radar network structure. Generally, radar network structure optimization consists of two aspects, namely the placement of receivers in suitable places and selection of appropriate illuminators. The present study investigates issues concerning the joint optimization of receiver placement and illuminator selection for a passive radar network. Firstly, the required radar cross section (RCS) for target detection is chosen as the performance metric, and the joint optimization model boils down to the partition p-center problem (PPCP). The PPCP is then solved by a proposed bisection algorithm. The key of the bisection algorithm lies in solving the partition set covering problem (PSCP), which can be solved by a hybrid algorithm developed by coupling the convex optimization with the greedy dropping algorithm. In the end, the performance of the proposed algorithm is validated via numerical simulations.

  9. Research and development cooperation project on environmental measurement using laser radar (environmental network) in fiscal 1993; Kankyo keisokuyo laser radar no kaihatsu ni kansuru kenkyu kyoryoku (kankyo network)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-03-01

    For the purpose of contributing to the research cooperation project on the development of a laser radar for environmental measurement, the paper surveyed the present and future trend of the environment related information network in Indonesia. The survey was conducted in terms of a name of the network, the main administration body, the number of users, the utilization status, the use protocol, details of service, domestic mode installation sites and the main administration body, accounting system, types of the network used, reliability and stability of network, limitations on the use and details of the limitation, etc. The plan for expanding telecommunication equipment is being advanced in a very quick tempo. However, there are many problems in digitalization, and it is feared that the plan will be delayed. As to telecommunication quality and connection quality, the telecommunication completion rate, SCR, is very low, approximately 24% on average, which is equal to that around 1990 in Japan. The business service for users is all bureaucratic since they have a lot of applications for the installation piling up with no exception to the rule of developing countries. 23 figs., 10 tabs.

  10. Indoor radar SLAM A radar application for vision and GPS denied environments

    OpenAIRE

    Marck, J.W.; Mohamoud, A.A.; Houwen, E.H. van de; Heijster, R.M.E.M. van

    2013-01-01

    Indoor navigation especially in unknown areas is a real challenge. Simultaneous Localization and Mapping (SLAM) technology provides a solution. However SLAM as currently based on optical sensors, is unsuitable in vision denied areas, which are for example encountered by first responders. Radar can be used to overcome this drawback, however no fully suitable solutions are reported yet. This paper presents radar SLAM technology for indoor use and shows its operational applicability. Modern elec...

  11. Polarimetric weather radar retrieval of raindrop size distribution by means of a regularized artificial neural network

    NARCIS (Netherlands)

    Vulpiani, G.; Marzano, F.S.; Chandrasekar, V.; Berne, A.D.; Uijlenhoet, R.

    2006-01-01

    The raindrop size distribution (RSD) is a critical factor in estimating rain intensity using advanced dual-polarized weather radars. A new neural-network algorithm to estimate the RSD from S-band dual-polarized radar measurements is presented. The corresponding rain rates are then computed assuming

  12. Application of borehole radar to South Africa’s Ultra-Deep gold mining environment

    CSIR Research Space (South Africa)

    Trickett, JC

    2000-05-01

    Full Text Available Borehole Radar has been identified as the most immediately applicable electromagnetic technique to delineate disruptions to gold reef in the South African Deepmine environment. The economically important Ventersdorp Contact Reef (VCR) has...

  13. GPM GROUND VALIDATION ENVIRONMENT CANADA (EC) MICRO RAIN RADAR (MRR) GCPEX V1

    Data.gov (United States)

    National Aeronautics and Space Administration — Environment Canada (EC) collected data from the Micro Rain Radar (MRR) during the GPM Cold-season Precipitation Experiment (GCPEx) in Ontario, Canada during the...

  14. Subsidence feature discrimination using deep convolutional neral networks in synthetic aperture radar imagery

    CSIR Research Space (South Africa)

    Schwegmann, Colin P

    2017-07-01

    Full Text Available International Geoscience and Remote Sensing Symposium (IGARSS), 23-28 July 2017, Fort Worth, TX, USA SUBSIDENCE FEATURE DISCRIMINATION USING DEEP CONVOLUTIONAL NEURAL NETWORKS IN SYNTHETIC APERTURE RADAR IMAGERY Schwegmann, Colin P Kleynhans, Waldo...

  15. Distributed radar network for real-time tracking of bullet trajectory

    Science.gov (United States)

    Zhang, Yimin; Li, Xin; Jin, Yuanwei; Amin, Moeness G.; Eydgahi, Ali

    2009-05-01

    Gunshot detection, sniper localization, and bullet trajectory prediction are of significant importance in military and homeland security applications. While the majority of existing work is based on acoustic and electro-optical sensors, this paper develops a framework of networked radar systems that uses distributed radar sensor networks to achieve the aforementioned objectives. The use of radio frequency radar systems allows the achievement of subtime- of-flight tracking response, enabling to response before the bullet reaches its target and, as such, effectively leading to the reduction of injuries and casualties in military and homeland security operations. The focus of this paper is to examine the MIMO radar concept with concurrent transmission of low-correlation waveforms from multiple radar sets to ensure wide surveillance coverage and maintain a high waveform repetition frequency for long coherent time interval required to achieve return signal concentration.

  16. Indoor radar SLAM A radar application for vision and GPS denied environments

    NARCIS (Netherlands)

    Marck, J.W.; Mohamoud, A.A.; Houwen, E.H. van de; Heijster, R.M.E.M. van

    2013-01-01

    Indoor navigation especially in unknown areas is a real challenge. Simultaneous Localization and Mapping (SLAM) technology provides a solution. However SLAM as currently based on optical sensors, is unsuitable in vision denied areas, which are for example encountered by first responders. Radar can

  17. Development of a global education environment to study the Equatorial Ionosphere with Cognitive Radars

    Science.gov (United States)

    Urbina, J. V.

    2011-12-01

    The author has recently been awarded the NSF Career award to develop a radar with cognitive sensing capabilities to study Equatorial plasma instabilities in the Peruvian Andes. Educational research has shown that a rich learning environment contributes tremendously toward improvement in learning achievements and also attitudes toward studies. One of the benefits of this project is that it provides such an environment and a global platform to involve several students at both graduate and undergraduate levels from the US, Puerto Rico, and Peru, and who will benefit from designing, installing, and deploying a radar in multi-instrument science campaigns. In addition to working in the laboratories, students will gain invaluable real world experience building this complex instrument and making it work under challenging conditions at remote sites. The PI will describe how these components are being developed in a Freshman Seminar course and Graduate courses in the Department of Electrical Engineering at Penn State University, and how they are aligned well with the department's and university's strategy for greater global engagement through a network of Global Engagement Nodes in South America (GENSA). The issues of mentoring, recruitment, and retention become particularly important in consideration of the educational objective of this career project to involve underrepresented students with diverse backgrounds and interest them in research projects. The author is working very closely with the Office of Engineering Diversity to leverage existing programs at Penn State designed to increase the participation of women and minority students in science and engineering research: (a) WISER (Women In Science and Engineering Research), and (b) MURE (Minority Undergraduate Research Experience). The Electrical Engineering Department at Penn State is also currently an NSF REU (Research Experience for Undergraduates) site. The PI will also present his efforts in connecting his career

  18. The RITMARE coastal radar network and applications to monitor marine transport infrastructures

    Science.gov (United States)

    Carrara, Paola; Corgnati, Lorenzo; Cosoli, Simone; Griffa, Annalisa; Kalampokis, Alkiviadis; Mantovani, Carlo; Oggioni, Alessandro; Pepe, Monica; Raffa, Francesco; Serafino, Francesco; Uttieri, Marco; Zambianchi, Enrico

    2014-05-01

    Coastal radars provide information on the environmental state of oceans, namely maps of surface currents at time intervals of the order of one hour with spatial coverage of the order of several km, depending on the transmission frequency. The observations are of crucial importance for monitoring ports and ship tracks close to the coast, providing support for safe navigation in densely operated areas and fast response in case of accidents at sea, such as oil spill or search and rescue. Besides these applications, coastal radar observations provide fundamental support in MPAs surveillance, connectivity and marine population circulation. In the framework of the Italian RITMARE flagship project coordinated by CNR (Consiglio Nazionale delle Ricerche), a coastal radar network has been designed and implemented with a number of innovative characteristics. The network includes both HF and X-band radars, allowing coverage of wide areas with different spatial and temporal resolutions. HF radars cover up to 80 km with a spatial resolution ranging between 1 and 5 km, while X-band radars provide 5 km coverage with a spatial resolution of 10 m. Joining these two capabilities, the RITMARE coastal radar network enables both a highly effective coverage of wide coastal areas and integrated monitoring of different phenomena, thus allowing the collection of current and wave parameters and detection of bathymetries of both open sea and coastal areas. A dedicated action to foster interoperability among data providers has been undertaken within RITMARE; an IT framework is under development to provide software tools for data collection and data sharing. It suggests standard, data format definitions, Quality Control strategies, data management and dissemination policies. In particular, the implementation of tools exploits both standards of OGC (Open Geospatial Consortium) and web services offered to manage, access and deliver geospatial data. Radar data produced in RITMARE by the coastal

  19. Considerations on radar localization in multi-target environments

    Directory of Open Access Journals (Sweden)

    H. Rabe

    2009-05-01

    Full Text Available In a multitude of applications like e.g. in automotive radar systems a localization of multiple passive targets in the observed area is necessary. This contribution presents a robust approach based on trilateration to detect point scatterers in a two-dimensional plane using the reflection and transmission information of only two antennas. The proposed algorithm can identify and remove ambiguities in target detection which unavoidably occur in certain target constellations in such a two-antenna configuration.

  20. Considerations on radar localization in multi-target environments

    Science.gov (United States)

    Rabe, H.; Denicke, E.; Armbrecht, G.; Musch, T.; Rolfes, I.

    2009-05-01

    In a multitude of applications like e.g. in automotive radar systems a localization of multiple passive targets in the observed area is necessary. This contribution presents a robust approach based on trilateration to detect point scatterers in a two-dimensional plane using the reflection and transmission information of only two antennas. The proposed algorithm can identify and remove ambiguities in target detection which unavoidably occur in certain target constellations in such a two-antenna configuration.

  1. An Energy Consumption Optimized Clustering Algorithm for Radar Sensor Networks Based on an Ant Colony Algorithm

    Directory of Open Access Journals (Sweden)

    Jiang Ting

    2010-01-01

    Full Text Available We optimize the cluster structure to solve problems such as the uneven energy consumption of the radar sensor nodes and random cluster head selection in the traditional clustering routing algorithm. According to the defined cost function for clusters, we present the clustering algorithm which is based on radio-free space path loss. In addition, we propose the energy and distance pheromones based on the residual energy and aggregation of the radar sensor nodes. According to bionic heuristic algorithm, a new ant colony-based clustering algorithm for radar sensor networks is also proposed. Simulation results show that this algorithm can get a better balance of the energy consumption and then remarkably prolong the lifetime of the radar sensor network.

  2. Regional Attenuation Correction of Weather Radar Using a Distributed Microwave-Links Network

    Directory of Open Access Journals (Sweden)

    Yang Xue

    2017-01-01

    Full Text Available The complex temporal-spatial variation of raindrop size distribution will affect the precision of precipitation quantitative estimates (QPE produced from radar data, making it difficult to correct echo attenuation. Given the fact that microwave links can obtain the total path attenuation accurately, we introduce the concept of regional attenuation correction using a multiple-microwave-links network based on the tomographic reconstruction of attenuation coefficients. Derived from the radar-based equation, the effect of rainfall distribution on the propagation of radar and microwave link signals was analyzed. This article focuses on modeling of the tomographic reconstruction of attenuation coefficients and regional attenuation correction algorithms. Finally, a numerical simulation of regional attenuation correction was performed to verify the algorithms employed here. The results demonstrate that the correction coefficient (0.9175 falls between the corrected and initial field of radar reflectivity factor (root mean square error, 2.3476 dBz; average deviation, 0.0113 dBz. Compared with uncorrected data, the accuracy of the corrected radar reflectivity factor was improved by 26.12%, and the corrected rainfall intensity distribution was improved by 51.85% validating the region attenuation correction algorithm. This method can correct the regional attenuation of weather radar echo effectively and efficiently; it can be widely used for the radar attenuation correction and the promotion of quantitative precipitation estimation by weather radar.

  3. A metric for the Radial Basis Function Network - Application on Real Radar Data

    NARCIS (Netherlands)

    Heiden, R. van der; Groen, F.C.A.

    1996-01-01

    A Radial Basis Functions (RBF) network for pattern recognition is considered. Classification with such a network is based on distances between patterns, so a metric is always present. Using real radar data, the Euclidean metric is shown to perform poorly - a metric based on the so called Box-Cox

  4. Regional Attenuation Correction of Weather Radar Using a Distributed Microwave-Links Network

    OpenAIRE

    Yang Xue; Xi-chuan Liu; Tai-chang Gao; Chang-ye Yang; Kun Song

    2017-01-01

    The complex temporal-spatial variation of raindrop size distribution will affect the precision of precipitation quantitative estimates (QPE) produced from radar data, making it difficult to correct echo attenuation. Given the fact that microwave links can obtain the total path attenuation accurately, we introduce the concept of regional attenuation correction using a multiple-microwave-links network based on the tomographic reconstruction of attenuation coefficients. Derived from the radar-ba...

  5. On the Statistical Errors of RADAR Location Sensor Networks with Built-In Wi-Fi Gaussian Linear Fingerprints

    Directory of Open Access Journals (Sweden)

    Shuo Tian

    2012-03-01

    Full Text Available The expected errors of RADAR sensor networks with linear probabilistic location fingerprints inside buildings with varying Wi-Fi Gaussian strength are discussed. As far as we know, the statistical errors of equal and unequal-weighted RADAR networks have been suggested as a better way to evaluate the behavior of different system parameters and the deployment of reference points (RPs. However, up to now, there is still not enough related work on the relations between the statistical errors, system parameters, number and interval of the RPs, let alone calculating the correlated analytical expressions of concern. Therefore, in response to this compelling problem, under a simple linear distribution model, much attention will be paid to the mathematical relations of the linear expected errors, number of neighbors, number and interval of RPs, parameters in logarithmic attenuation model and variations of radio signal strength (RSS at the test point (TP with the purpose of constructing more practical and reliable RADAR location sensor networks (RLSNs and also guaranteeing the accuracy requirements for the location based services in future ubiquitous context-awareness environments. Moreover, the numerical results and some real experimental evaluations of the error theories addressed in this paper will also be presented for our future extended analysis.

  6. LPI Optimization Framework for Target Tracking in Radar Network Architectures Using Information-Theoretic Criteria

    Directory of Open Access Journals (Sweden)

    Chenguang Shi

    2014-01-01

    Full Text Available Widely distributed radar network architectures can provide significant performance improvement for target detection and localization. For a fixed radar network, the achievable target detection performance may go beyond a predetermined threshold with full transmitted power allocation, which is extremely vulnerable in modern electronic warfare. In this paper, we study the problem of low probability of intercept (LPI design for radar network and propose two novel LPI optimization schemes based on information-theoretic criteria. For a predefined threshold of target detection, Schleher intercept factor is minimized by optimizing transmission power allocation among netted radars in the network. Due to the lack of analytical closed-form expression for receiver operation characteristics (ROC, we employ two information-theoretic criteria, namely, Bhattacharyya distance and J-divergence as the metrics for target detection performance. The resulting nonconvex and nonlinear LPI optimization problems associated with different information-theoretic criteria are cast under a unified framework, and the nonlinear programming based genetic algorithm (NPGA is used to tackle the optimization problems in the framework. Numerical simulations demonstrate that our proposed LPI strategies are effective in enhancing the LPI performance for radar network.

  7. Cross-evaluation of reflectivity from the space-borne precipitation radar and multi-type ground-based weather radar network in China

    Science.gov (United States)

    Zhong, Lingzhi; Yang, Rongfang; Wen, Yixin; Chen, Lin; Gou, Yabin; Li, Ruiyi; Zhou, Qing; Hong, Yang

    2017-11-01

    China operational weather radar network consists of more than 200 ground-based radars (GR(s)). The lack of unified calibrators often result in poor mosaic products as well as its limitation in radar data assimilation in numerical models. In this study, radar reflectivity and precipitation vertical structures observed from space-borne TRMM (Tropical Rainfall Measurement Mission) PR (precipitation radar) and GRs are volumetrically matched and cross-evaluated. It is found that observation of GRs is basically consistent with that of PR. For their overlapping scanning regions, the GRs are often affected by the beam blockage for complex terrain. The statistics show the better agreement among S band A type (SA) radars, S band B type (SB) radars and PR, as well as poor performance of S band C type (SC) radars. The reflectivity offsets between GRs and PR depend on the reflectivity magnitudes: They are positive for weak precipitation and negative for middle and heavy precipitation, respectively. Although the GRs are quite consistent with PR for large sample, an individual GR has its own fluctuated biases monthly. When the sample number is small, the bias statistics may be determined by a single bad GR in a group. Results from this study shed lights that the space-borne precipitation radars could be used to quantitatively calibrate systematic bias existing in different GRs in order to improve the consistency of ground-based weather radar network across China, and also bears the promise to provide a robust reference even form a space and ground constellation network for the dual-frequency precipitation radars onboard the satellites anticipated in the near future.

  8. On the Implementation of a Regional X-Band Weather Radar Network

    Directory of Open Access Journals (Sweden)

    Andrea Antonini

    2017-01-01

    Full Text Available In the last few years, the number of worldwide operational X-band weather radars has rapidly been growing, thanks to an established technology that offers reliability, high performance, and reduced efforts and costs for installation and maintenance, with respect to the more widespread C- and S-band systems. X-band radars are particularly suitable for nowcasting activities, as those operated by the LaMMA (Laboratory of Monitoring and Environmental Modelling for the sustainable development Consortium in the framework of its institutional duties of operational meteorological surveillance. In fact, they have the capability to monitor precipitation, resolving very local scales, with good spatial and temporal details, although with a reduced scanning range. The Consortium has recently installed a small network of X-band weather radars that partially overlaps and completes the existing national radar network over the north Tyrrhenian area. This paper describes the implementation of this regional network, detailing the aspects related with the radar signal processing chain that provides the final reflectivity composite, starting from the acquisition of the signal power data. The network performances are then qualitatively assessed for three case studies characterised by different precipitation regimes and different seasons. Results are satisfactory especially during intense precipitations, particularly regarding what concerns their spatial and temporal characterisation.

  9. Doppler radar observation of thunderstorm circulation in the 1977 trip program. [triple Doppler radar network for lightning detection and ranging

    Science.gov (United States)

    Lhermitte, R. M.; Conte, D.; Pasqualucci, F.; Lennon, C.; Serafin, R. J.

    1978-01-01

    Storm data obtained on August 1, 1977 are examined in an attempt to interpret the relationship between lightning occurrence and the thunderstorm inner dynamics and precipitation processes. Horizontal maps are presented which indicated the position of radiation sources detected by the Lightning Detection and Ranging (LDAR) network, together with the horizontal motion fields and radar reflectivity data. Detailed inspection of these fields showed that, although radiation sources are found in the vicinity of precipitation cells, they are not located in the heavy precipitation areas, but rather on their rear side in regions where the configuration of the wind fields suggests the presence of updrafts.

  10. INCREASE: Innovation and Networking for the integration of Coastal Radars into European mArine SErvices

    Science.gov (United States)

    Mader, Julien; Rubio, Anna; Asensio Igoa, Jose Luis; Corgnati, Lorenzo; Mantovani, Carlo; Griffa, Annalisa; Gorringe, Patrick; Alba, Marco; Novellino, Antonio

    2017-04-01

    High Frequency radar (HFR) is a land-based remote sensing instrument offering a unique insight to coastal ocean variability, by providing synoptic, high frequency and high resolution data at the ocean atmosphere interface. HFRs have become invaluable tools in the field of operational oceanography for measuring surface currents, waves and winds, with direct applications in different sectors and an unprecedented potential for the integrated management of the coastal zone. To further the use of HFRs into the Copernicus Marine environment monitoring service, CMEMS, is becoming crucial to ensure the improved management of several related key issues such as Marine Safety, Marine Resources, Coastal & Marine Environment, Weather, Climate & Seasonal Forecast. In this context, INCREASE (Innovation and Networking for the integration of Coastal Radars into European mArine SErvices) project aims to set the necessary developments towards the integration of the existing European HFR operational systems into the CMEMS, following five main objectives: (i) Define and implement a common data and metadata model for HFR real-time data; (ii) Provide HFR quality controlled real-time surface currents and key derived products; (iii) Set the basis for the management of historical data and methodologies for advanced delayed mode quality-control techniques; (iv) Advance the use of HFR data for improving CMEMS numerical modelling systems; and (v) Enable an HFR European operational node to ensure the link with operational CMEMS. In cooperation with other ongoing initiatives (like the EuroGOOS HFR Task Team and the European project JERICO_NEXT), INCREASE has already set up the data management infrastructure to manage and make discoverable and accessible near real time data from 30 systems in Europe. This paper presents the achieved results and available products and features.

  11. Multistatic Wireless Fidelity Network Based Radar – Results of the Chrcynno Experiment

    Directory of Open Access Journals (Sweden)

    S. Rzewuski

    2014-04-01

    Full Text Available This paper presents the theory and experimental result of passive radar using WIFI transmitters as illuminators of opportunity. As a result of experiments conducted on 17th August 2013 at airfield Chrcynno a Cessna C208 airplane was detected and tracked using multistatic passive radar system based on low power signal from WIFI network nodes, which were acting as non cooperative illuminators of opportunity. In the experiment 3 wireless access points were communicating with each other and illuminating the radar scene (airfield. The direct reference and reflected (surveillance signals have been acquired and processed using specially developed algorithm presented in the paper. After signal processing using Passive Coherent Location methods target has been detected. This paper describes in details the algorithms and the results of the experiment for the multistatic passive radar based on the WIFI signal.

  12. Multipath Exploitation in an Urban Environment using a MIMO Surveillance Radar

    NARCIS (Netherlands)

    Deiana, D.; Kossen, A.S.; Rossum, W.L. van

    2010-01-01

    Surveillance in an urban environment under all atmospheric conditions and situations can be performed by means of radars. The multipath created by buildings and moving targets can be exploited, for example in order to increase SNR. In this paper we present the initial results of the measurements of

  13. Application of MIMO Techniques in sky-surface wave hybrid networking sea-state radar system

    Science.gov (United States)

    Zhang, L.; Wu, X.; Yue, X.; Liu, J.; Li, C.

    2016-12-01

    The sky-surface wave hybrid networking sea-state radar system contains of the sky wave transmission stations at different sites and several surface wave radar stations. The subject comes from the national 863 High-tech Project of China. The hybrid sky-surface wave system and the HF surface wave system work simultaneously and the HF surface wave radar (HFSWR) can work in multi-static and surface-wave networking mode. Compared with the single mode radar system, this system has advantages of better detection performance at the far ranges in ocean dynamics parameters inversion. We have applied multiple-input multiple-output(MIMO) techniques in this sea-state radar system. Based on the multiple channel and non-causal transmit beam-forming techniques, the MIMO radar architecture can reduce the size of the receiving antennas and simplify antenna installation. Besides, by efficiently utilizing the system's available degrees of freedom, it can provide a feasible approach for mitigating multipath effect and Doppler-spread clutter in Over-the-horizon Radar. In this radar, slow-time phase-coded MIMO method is used. The transmitting waveforms are phase-coded in slow-time so as to be orthogonal after Doppler processing at the receiver. So the MIMO method can be easily implemented without the need to modify the receiver hardware. After the radar system design, the MIMO experiments of this system have been completed by Wuhan University during 2015 and 2016. The experiment used Wuhan multi-channel ionospheric sounding system(WMISS) as sky-wave transmitting source and three dual-frequency HFSWR developed by the Oceanography Laboratory of Wuhan University. The transmitter system located at Chongyang with five element linear equi-spaced antenna array and Wuhan with one log-periodic antenna. The RF signals are generated by synchronized, but independent digital waveform generators - providing complete flexibility in element phase and amplitude control, and waveform type and parameters

  14. Radar Characterization of the Interplanetary Meteoroid Environment Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a new modeling effort that will make substantial refinements and improvements to our existing models of the interplanetary meteoroid environment near...

  15. MARSnet: Mission-aware Autonomous Radar Sensor Network for Future Combat Systems

    Science.gov (United States)

    2008-07-31

    West Virginia Sago mine disaster in January 2006, cognitive radar sensor network-based information integration for first responders is critical for...power supply and Utah Mine Collapse in August 2007 or West Virginia Sago Weather shield (small hut). The target is a trihedral reflector mine disaster in

  16. Network connectivity paradigm for the large data produced by weather radar systems

    Science.gov (United States)

    Guenzi, Diego; Bechini, Renzo; Boraso, Rodolfo; Cremonini, Roberto; Fratianni, Simona

    2014-05-01

    The traffic over Internet is constantly increasing; this is due in particular to social networks activities but also to the enormous exchange of data caused especially by the so-called "Internet of Things". With this term we refer to every device that has the capability of exchanging information with other devices on the web. In geoscience (and, in particular, in meteorology and climatology) there is a constantly increasing number of sensors that are used to obtain data from different sources (like weather radars, digital rain gauges, etc.). This information-gathering activity, frequently, must be followed by a complex data analysis phase, especially when we have large data sets that can be very difficult to analyze (very long historical series of large data sets, for example), like the so called big data. These activities are particularly intensive in resource consumption and they lead to new computational models (like cloud computing) and new methods for storing data (like object store, linked open data, NOSQL or NewSQL). The weather radar systems can be seen as one of the sensors mentioned above: it transmit a large amount of raw data over the network (up to 40 megabytes every five minutes), with 24h/24h continuity and in any weather condition. Weather radar are often located in peaks and in wild areas where connectivity is poor. For this reason radar measurements are sometimes processed partially on site and reduced in size to adapt them to the limited bandwidth currently available by data transmission systems. With the aim to preserve the maximum flow of information, an innovative network connectivity paradigm for the large data produced by weather radar system is here presented. The study is focused on the Monte Settepani operational weather radar system, located over a wild peak summit in north-western Italy.

  17. Updating the NASA LEO Orbital Debris Environment Model with Recent Radar and Optical Observations and in Situ Measurements

    Science.gov (United States)

    Liou, J.-C.; Anz-Meador, P.; Matney, M. J.; Kessler, D. J.; Theall, J.; Johnson, N. L.

    2000-01-01

    The Low Earth Orbit (LEO, between 200 and 2000 km altitudes) debris environment has been constantly measured by NASA Johnson Space Center's Liquid Mirror Telescope (LMT) since 1996 (Africano et al. 1999, NASA JSC-28826) and by Haystack and Haystack Auxiliary radars at MIT Lincoln Laboratory since 1990 (Settecerri et al. 1999, NASA JSC-28744). Debris particles as small as 3 mm can be detected by the radars and as small as 3 cm can be measured by LMT. Objects about 10 cm in diameter and greater are tracked and catalogued by the US Space Surveillance Network. Much smaller (down to several micrometers) natural and debris particle populations can be estimated based on in situ measurements, such as Long Duration Exposure Facility, and based on analyses of returned surfaces, such as Hubble Space Telescope solar arrays, European Retrievable Carrier, and Space Shuttles. To increase our understanding of the current LEO debris environment, the Orbital Debris Program Office at NASA JSC has initiated an effort to improve and update the ORDEM96 model (Kessler et al. 1996, NASA TM-104825) utilizing the recently available data. This paper gives an overview of the new NASA orbital debris engineering model, ORDEM2000.

  18. The ISMAR high frequency coastal radar network: Monitoring surface currents for management of marine resources

    DEFF Research Database (Denmark)

    Carlson, Daniel Frazier

    2015-01-01

    The Institute of Marine Sciences (ISMAR) of the National Research Council of Italy (CNR) established a High Frequency (HF) Coastal Radar Network for the measurement of the velocity of surface currents in coastal seas. The network consists of four HF radar systems located on the coast of the Gargano...... Promontory (Southern Adriatic, Italy). The network has been operational since May 2013 and covers an area of approximately 1700 square kilometers in the Gulf of Manfredonia. Quality Assessment (QA) procedures are applied for the systems deployment and maintenance and Quality Control (QC) procedures...... of geospatial data, a netCDF architecture has been defined on the basis of the Radiowave Operators Working Group (US ROWG) recommendations and compliant to the Climate and Forecast (CF) Metadata Conventions CF-1.6. The hourly netCDF files are automatically attached to a Thematic Real-time Environmental...

  19. Building a Network Based Laboratory Environment

    Directory of Open Access Journals (Sweden)

    Sea Shuan Luo

    2009-12-01

    Full Text Available This paper presents a comparative study about the development of a network based laboratory environment in the “Unix introduction” course for the undergraduate students. The study results and the response from the students from 2005 to 2006 will be used to better understand what kind of method is more suitable for students. We also use the data collected to adjust our teaching strategy and try to build up a network based laboratory environment.

  20. Optimal Power Allocation Algorithm for Radar Network Systems Based on Low Probability of Intercept Optimization(in English

    Directory of Open Access Journals (Sweden)

    Shi Chen-guang

    2014-08-01

    Full Text Available A novel optimal power allocation algorithm for radar network systems is proposed for Low Probability of Intercept (LPI technology in modern electronic warfare. The algorithm is based on the LPI optimization. First, the Schleher intercept factor for a radar network is derived, and then the Schleher intercept factor is minimized by optimizing the transmission power allocation among netted radars in the network to guarantee target-tracking performance. Furthermore, the Nonlinear Programming Genetic Algorithm (NPGA is used to solve the resulting nonconvex, nonlinear, and constrained optimization problem. Numerical simulation results show the effectiveness of the proposed algorithm.

  1. A Radar-Enabled Collaborative Sensor Network Integrating COTS Technology for Surveillance and Tracking

    Directory of Open Access Journals (Sweden)

    R. Murat Demirer

    2012-01-01

    Full Text Available The feasibility of using Commercial Off-The-Shelf (COTS sensor nodes is studied in a distributed network, aiming at dynamic surveillance and tracking of ground targets. Data acquisition by low-cost ( < $50 US miniature low-power radar through a wireless mote is described. We demonstrate the detection, ranging and velocity estimation, classification and tracking capabilities of the mini-radar, and compare results to simulations and manual measurements. Furthermore, we supplement the radar output with other sensor modalities, such as acoustic and vibration sensors. This method provides innovative solutions for detecting, identifying, and tracking vehicles and dismounts over a wide area in noisy conditions. This study presents a step towards distributed intelligent decision support and demonstrates effectiveness of small cheap sensors, which can complement advanced technologies in certain real-life scenarios.

  2. A radar-enabled collaborative sensor network integrating COTS technology for surveillance and tracking.

    Science.gov (United States)

    Kozma, Robert; Wang, Lan; Iftekharuddin, Khan; McCracken, Ernest; Khan, Muhammad; Islam, Khandakar; Bhurtel, Sushil R; Demirer, R Murat

    2012-01-01

    The feasibility of using Commercial Off-The-Shelf (COTS) sensor nodes is studied in a distributed network, aiming at dynamic surveillance and tracking of ground targets. Data acquisition by low-cost (radar through a wireless mote is described. We demonstrate the detection, ranging and velocity estimation, classification and tracking capabilities of the mini-radar, and compare results to simulations and manual measurements. Furthermore, we supplement the radar output with other sensor modalities, such as acoustic and vibration sensors. This method provides innovative solutions for detecting, identifying, and tracking vehicles and dismounts over a wide area in noisy conditions. This study presents a step towards distributed intelligent decision support and demonstrates effectiveness of small cheap sensors, which can complement advanced technologies in certain real-life scenarios.

  3. Large networks of artificial radar reflectors to monitor land subsidence in natural lowlying coastal areas

    Science.gov (United States)

    Tosi, Luigi; Strozzi, Tazio; Teatini, Pietro

    2014-05-01

    Deltas, lagoons, estuaries are generally much prone to land subsidence. They are also very sensitive to land lowering due to their small elevation with respect to the mean sea level, also in view of the expected eustatic sea rise due to climate changes. Land subsidence can be presently monitored with an impressive accuracy by Persistent Scatterer Interferometry (PSI) on the large megacities that are often located on lowlying coastlands, e.g., Shanghai (China) on the Yangtze River delta, Dhaka (Bangladesh) on the Gange River delta, New Orleans (Louisiana) on the Mississippi river delta. Conversely, the land movements of the portions of these transitional coastlands where natural environments still persist are very challenging to be measured. The lack of anthropogenic structures strongly limits the use of PSI and the difficult accessibility caused by the presence of marshlands, tidal marshes, channels, and ponds yield traditional methodologies, such as levelling and GPS, both time-consuming and costly. In this contribution we present a unique experimental study aimed at using a large network of artificial radar reflectors to measure land subsidence in natural coastal areas. The test site is the 60-km long, 10-15 km wide lagoon of Venice, Italy, where previous PSI investigations revealed the lack of radar reflectors in large portions of the northern and southern lagoon basins (e.g., Teatini et al., 2011). A network of 57 trihedral corner reflectors (TCRs) were established between the end of 2006 and the beginning of 2007 and monitored by ENVISAT ASAR and TerraSAR-X acquisitions covering the time period from 2007 to 2011 (Strozzi et al., 2012). The application has provided general important insights on the possibility of controlling land subsidence using this approach. For example: (i) relatively small-size (from 0.5 to 1.0 m edge length) and cheap (few hundred euros) TCRs suffice to be clearly detectable from the radar sensors because of the low backscattering

  4. A Novel Sensor Selection and Power Allocation Algorithm for Multiple-Target Tracking in an LPI Radar Network

    Directory of Open Access Journals (Sweden)

    Ji She

    2016-12-01

    Full Text Available Radar networks are proven to have numerous advantages over traditional monostatic and bistatic radar. With recent developments, radar networks have become an attractive platform due to their low probability of intercept (LPI performance for target tracking. In this paper, a joint sensor selection and power allocation algorithm for multiple-target tracking in a radar network based on LPI is proposed. It is found that this algorithm can minimize the total transmitted power of a radar network on the basis of a predetermined mutual information (MI threshold between the target impulse response and the reflected signal. The MI is required by the radar network system to estimate target parameters, and it can be calculated predictively with the estimation of target state. The optimization problem of sensor selection and power allocation, which contains two variables, is non-convex and it can be solved by separating power allocation problem from sensor selection problem. To be specific, the optimization problem of power allocation can be solved by using the bisection method for each sensor selection scheme. Also, the optimization problem of sensor selection can be solved by a lower complexity algorithm based on the allocated powers. According to the simulation results, it can be found that the proposed algorithm can effectively reduce the total transmitted power of a radar network, which can be conducive to improving LPI performance.

  5. A Novel Sensor Selection and Power Allocation Algorithm for Multiple-Target Tracking in an LPI Radar Network.

    Science.gov (United States)

    She, Ji; Wang, Fei; Zhou, Jianjiang

    2016-12-21

    Radar networks are proven to have numerous advantages over traditional monostatic and bistatic radar. With recent developments, radar networks have become an attractive platform due to their low probability of intercept (LPI) performance for target tracking. In this paper, a joint sensor selection and power allocation algorithm for multiple-target tracking in a radar network based on LPI is proposed. It is found that this algorithm can minimize the total transmitted power of a radar network on the basis of a predetermined mutual information (MI) threshold between the target impulse response and the reflected signal. The MI is required by the radar network system to estimate target parameters, and it can be calculated predictively with the estimation of target state. The optimization problem of sensor selection and power allocation, which contains two variables, is non-convex and it can be solved by separating power allocation problem from sensor selection problem. To be specific, the optimization problem of power allocation can be solved by using the bisection method for each sensor selection scheme. Also, the optimization problem of sensor selection can be solved by a lower complexity algorithm based on the allocated powers. According to the simulation results, it can be found that the proposed algorithm can effectively reduce the total transmitted power of a radar network, which can be conducive to improving LPI performance.

  6. Sparsity-Based Optimization of the Sensors Positions in Radar Networks with Separated Transmit and Receive Nodes

    NARCIS (Netherlands)

    Ivashko, I.M.; Krasnov, O.A.; Yarovoy, A.G.

    2016-01-01

    A sparsity-based approach for the joint optimization of the transmit and the receive nodes positions in the radar network with widely distributed antennas is proposed in this paper. The optimization problem is formulated as minimization of the number of radars that meet fixed target localization

  7. Satellite synthetic aperture radar for monitoring of surface deformation in shallow underground mining environments

    CSIR Research Space (South Africa)

    Engelbrecht, J

    2016-08-01

    Full Text Available of using dInSAR is that large areas can be monitored in a single footprint. Satellites also orbit the meaning that frequent measurements can be made. Since measurements are made remotely, dInSAR effectively overcomes the limitations imposed by field... interferogram and associated deformation map over an area undergoing mining- induced subsidence Satellite synthetic aperture radar for monitoring of surface deformation in shallow underground mining environments Engelbrecht, J.1, and Inggs, M.R2 1...

  8. Combined flatland ST radar and digital-barometer network observations of mesoscale processes

    Science.gov (United States)

    Clark, W. L.; Vanzandt, T. E.; Gage, K. S.; Einaudi, F. E.; Rottman, J. W.; Hollinger, S. E.

    1991-01-01

    The paper describes a six-station digital-barometer network centered on the Flatland ST radar to support observational studies of gravity waves and other mesoscale features at the Flatland Atmospheric Observatory in central Illinois. The network's current mode of operation is examined, and a preliminary example of an apparent group of waves evident throughout the network as well as throughout the troposphere is presented. Preliminary results demonstrate the capabilities of the current operational system to study wave convection, wave-front, and other coherent mesoscale interactions and processes throughout the troposphere. Unfiltered traces for the pressure and horizontal zonal wind, for days 351 to 353 UT, 1990, are illustrated.

  9. Massivizing Networked Virtual Environments on Clouds

    NARCIS (Netherlands)

    Shen, S.

    2015-01-01

    Networked Virtual Environments (NVEs) are virtual environments where physically distributed, Internet-connected users can interact and socialize with others. The most popular NVEs are online games, which have hundreds of millions of users and a global market of tens of billions Euros per year.

  10. Scientific Visualization in High Speed Network Environments

    Science.gov (United States)

    Vaziri, Arsi; Kutler, Paul (Technical Monitor)

    1997-01-01

    In several cases, new visualization techniques have vastly increased the researcher's ability to analyze and comprehend data. Similarly, the role of networks in providing an efficient supercomputing environment have become more critical and continue to grow at a faster rate than the increase in the processing capabilities of supercomputers. A close relationship between scientific visualization and high-speed networks in providing an important link to support efficient supercomputing is identified. The two technologies are driven by the increasing complexities and volume of supercomputer data. The interaction of scientific visualization and high-speed networks in a Computational Fluid Dynamics simulation/visualization environment are given. Current capabilities supported by high speed networks, supercomputers, and high-performance graphics workstations at the Numerical Aerodynamic Simulation Facility (NAS) at NASA Ames Research Center are described. Applied research in providing a supercomputer visualization environment to support future computational requirements are summarized.

  11. The Dallas-Fort Worth (DFW) Urban Radar Network: Enhancing Resilience in the Presence of Floods, Tornadoes, Hail and High Winds

    Science.gov (United States)

    Chandra*, Chandrasekar V.; the full DFW Team

    2015-04-01

    Currently, the National Weather Service (NWS) Next Generation Weather Radar (NEXRAD) provides observations updated every five-six minutes across the United States. However, at the maximum NEXRAD operating range of 230 km, the 0.5 degree radar beam (lowest tilt) height is about 5.4 km above ground level (AGL) because of the effect of Earth curvature. Consequently, much of the lower atmosphere (1-3 km AGL) cannot be observed by the NEXRAD. To overcome the fundamental coverage limitations of today's weather surveillance radars, and improve the spatial and temporal resolution issues, at urban scale, the National Science Foundation Engineering Research Center (NSF-ERC) for Collaborative Adaptive Sensing of the Atmosphere (CASA) has embarked the development of Dallas-Fort worth (DFW) urban remote sensing network to conduct high-resolution sensing in the lower atmosphere for a metropolitan environment, communicate high resolution observations and nowcasting of severe weather including flash floods, hail storms and high wind events. Being one of the largest inland metropolitan areas in the U.S., the DFW Metroplex is home to over 6.5 million people by 2012 according to the North Central Texas Council of Governments (NCTCOG). It experiences a wide range of natural weather hazards, including urban flash flood, high wind, tornado, and hail, etc. Successful monitoring of the rapid changing meteorological conditions in such a region is necessary for emergency management and decision making. Therefore, it is an ideal location to investigate the impacts of hazardous weather phenomena, to enhance resilience in an urban setting and demonstrate the CASA concept in a densely populated urban environment. The DFW radar network consists of 8 dual-polarization X-band weather radars and standard NEXRAD S-band radar, covering the greater DFW metropolitan region. This paper will present high resolution observation of tornado, urban flood, hail storm and damaging wind event all within the

  12. Portability and networked learning environments

    NARCIS (Netherlands)

    Collis, Betty; de Diana, I.P.F.

    1994-01-01

    Abstract The portability of educational software is defined as the likelihood of software usage, with or without adaptation, in an educational environment different from that for which it was originally designed and produced. Barriers and research relevant to the portability of electronic learning

  13. Research and development cooperation project on environmental measurement using laser radar in fiscal 1995 (environmental network); Kankyo keisokuyo laser radar no kaihatsu ni kansuru kenkyu kyoryoku (kankyo network)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    As a part of the cooperative work with Indonesia of R and D of a laser radar for environmental measurement, the paper described the development of an environmental network. The field survey was conducted in April, July and December 1995 and in March 1996. For the investigational research, five meetings of the committee and four times of group work were held. The Asian environmental network was studied in terms of its arrangement, operation and management, and the overall network/path control design were being prepared. To make the persons concerned abroad and in Japan understood the APEC Osaka Conference held in November 1995, a homepage APEC `95 Kansai was opened using WWW (World Wide Web, a decentralized hyper media system which can dispatch information to the whole world by network using hyper text). Moreover, in connection with this, a homepage was opened of CICC (Center of the International Cooperation for Computerization, a center controlling the whole Asian environmental information network system where E-mail and data are exchangeable with Indonesia via Tokyo NOC (Network Operation Center)). 49 figs., 8 tabs.

  14. Social network analysis of study environment

    Directory of Open Access Journals (Sweden)

    Blaženka Divjak

    2010-06-01

    Full Text Available Student working environment influences student learning and achievement level. In this respect social aspects of students’ formal and non-formal learning play special role in learning environment. The main research problem of this paper is to find out if students' academic performance influences their position in different students' social networks. Further, there is a need to identify other predictors of this position. In the process of problem solving we use the Social Network Analysis (SNA that is based on the data we collected from the students at the Faculty of Organization and Informatics, University of Zagreb. There are two data samples: in the basic sample N=27 and in the extended sample N=52. We collected data on social-demographic position, academic performance, learning and motivation styles, student status (full-time/part-time, attitudes towards individual and teamwork as well as informal cooperation. Afterwards five different networks (exchange of learning materials, teamwork, informal communication, basic and aggregated social network were constructed. These networks were analyzed with different metrics and the most important were betweenness, closeness and degree centrality. The main result is, firstly, that the position in a social network cannot be forecast only by academic success and, secondly, that part-time students tend to form separate groups that are poorly connected with full-time students. In general, position of a student in social networks in study environment can influence student learning as well as her/his future employability and therefore it is worthwhile to be investigated.

  15. Radar equations for modern radar

    CERN Document Server

    Barton, David K

    2012-01-01

    Based on the classic Radar Range-Performance Analysis from 1980, this practical volume extends that work to ensure applicability of radar equations to the design and analysis of modern radars. This unique book helps you identify what information on the radar and its environment is needed to predict detection range. Moreover, it provides equations and data to improve the accuracy of range calculations. You find detailed information on propagation effects, methods of range calculation in environments that include clutter, jamming and thermal noise, as well as loss factors that reduce radar perfo

  16. MARSnet: Mission-aware Autonomous Radar Sensor Network for Future Combat Systems

    Science.gov (United States)

    2009-03-23

    Nevertheless, as an additional source of error, the in- terference from external network also play an important role in defining the quality of the link. To...beamformer at the receiver antenna is V = ££i Ane*»i-*«>£.« T.yiX*eH*7-**)E,8 E"l^M<jl^~"N)EsS + II (21) 16 Whore Es >> a 2{ri). In MIMO radar for

  17. US Integrated Ocean Observing System HF Radar Network: National Applications and International Implementation

    Science.gov (United States)

    Harlan, J.

    2016-12-01

    The US Integrated Ocean Observing System (IOOS), a partnership of academic institutions and Federal agencies, within NOAA National Ocean Service (NOS), operates the nation's only high-frequency (HF) radar network providing near-real-time 2-D maps of ocean of surface currents speed and direction. This system supports US Coast Guard search and rescue operations, NOAA response to oil spills, port navigation and tracking of harmful algal bloom. In the research realm, the data are helping to understand oceanographic processes such as the warm water mass off of the west coast of the US and are routinely ingested into oceanographic models and are used for research into tsunami detection. A key component of the network is the data management system that ingests and distributes hourly data from radars throughout US coastal areas as well as Canada and Mexico, comprising nearly 150 radars. HF radar operators outside the US have adopted the data file formats that were developed by the US IOOS and these data are displayed publicly in near-real-time. To enhance the utility of HF radar data to end-users in all parts of the globe, operational products are needed. Recently in the US, quasi-operational products have been developed, or are under development, including: 2-D maps in AWIPS-II, tidal analysis and prediction from NOS Center for Operational Oceanographic Products & Services (CO-OPS), tsunami detection algorithms led by National Tsunami Warning Center, and significant wave height pilot project. These products will be highlighted and potential for international use discussed.

  18. Towards the creation of a multi-institutional HF Radar Network in the Gulf of Mexico.

    Science.gov (United States)

    Flores-vidal, X.; Flament, P. J.; Durazo, R.; Navarro, L. F.; Salles, P.; Alvarez, P.; Carrillo, L.; Kurczyn, J. A.; Ulloa, M. J.; Rodriguez, I.; Toro Valencia, V. G.; Marin, M.; Perales, H.; Sanay, R.

    2016-12-01

    The Gulf of Mexico is source of important resources for both Mexico and USA, its beaches and coasts bring economical resources for these countries through the generation of jobs on the fisheries, touristic and industrial sectors. However, systematic monitoring is still necessary to evaluate its health and dynamics. This work is part of a multi-institutional project named "Implementation of oceanographic observational networks (physical, geochemical and ecological) to generate scenarios for possible contingencies related to the exploration and production of hydrocarbons in the deep waters of the Gulf of Mexico" (funded by SENER-CONACyT) which is an unprecedented Mexican joint effort to better understand the dynamics in the Gulf of Mexico. We will present the first actions towards the creation of the Mexican multi-Institutional HF Radar Network, which will allow us to synoptically map in real time the sea surface currents up to 200 km offshore. We expect to attract collaborations with the active or ongoing USA HF radar stations and institutions along the Gulf of Mexico, as well as to share methodologies and to evaluate standard data formats. The Radar Network in the Gulf of Mexico is planned to be active during 2017-2018, and it is expected to be permanent.

  19. Enhanced Radar Imaging in Uncertain Environment: A Descriptive Experiment Design Regularization Approach

    Directory of Open Access Journals (Sweden)

    Yuriy Shkvarko

    2008-01-01

    Full Text Available A new robust technique for high-resolution reconstructive imaging is developed as required for enhanced remote sensing (RS with imaging array radar or/and synthetic aperture radar (SAR operating in an uncertain RS environment. The operational scenario uncertainties are associated with the unknown statistics of perturbations of the signal formation operator (SFO in turbulent medium, imperfect array calibration, finite dimensionality of measurements, uncontrolled antenna vibrations, and random carrier trajectory deviations in the case of SAR. We propose new descriptive experiment design regularization (DEDR approach to treat the uncertain radar image enhancement/reconstruction problems. The proposed DEDR incorporates into the minimum risk (MR nonparametric estimation strategy the experiment design-motivated operational constraints algorithmically coupled with the worst-case statistical performance (WCSP optimization-based regularization. The MR objective functional is constrained by the WCSP information, and the robust DEDR image reconstruction operator applicable to the scenarios with the low-rank uncertain estimated data correlation matrices is found. We report and discuss some simulation results related to enhancement of the uncertain SAR imagery indicative of the significantly increased performance efficiency gained with the developed approach.

  20. Social Environments, Sexual Networking and Adolescents ...

    African Journals Online (AJOL)

    This study investigated adolescents' social environments, different strategies manipulated for sexual networking and the effect on adolescents' heterosexual relationship in Lagos metropolis. The total sample for the study comprised 80 male and female adolescents randomly selected from two mixed secondary schools.

  1. Managing records in networked environment using EDRMS ...

    African Journals Online (AJOL)

    Managing records in networked environment using EDRMS applications: a case study of Rand Water. ... and archival story of Rand Water representing water sector challenges and opportunities that organisations such as this are faced with in consideration of the ever-improving technologies and strategies at their disposal.

  2. Error Analysis for RADAR Neighbor Matching Localization in Linear Logarithmic Strength Varying Wi-Fi Environment

    Directory of Open Access Journals (Sweden)

    Mu Zhou

    2014-01-01

    Full Text Available This paper studies the statistical errors for the fingerprint-based RADAR neighbor matching localization with the linearly calibrated reference points (RPs in logarithmic received signal strength (RSS varying Wi-Fi environment. To the best of our knowledge, little comprehensive analysis work has appeared on the error performance of neighbor matching localization with respect to the deployment of RPs. However, in order to achieve the efficient and reliable location-based services (LBSs as well as the ubiquitous context-awareness in Wi-Fi environment, much attention has to be paid to the highly accurate and cost-efficient localization systems. To this end, the statistical errors by the widely used neighbor matching localization are significantly discussed in this paper to examine the inherent mathematical relations between the localization errors and the locations of RPs by using a basic linear logarithmic strength varying model. Furthermore, based on the mathematical demonstrations and some testing results, the closed-form solutions to the statistical errors by RADAR neighbor matching localization can be an effective tool to explore alternative deployment of fingerprint-based neighbor matching localization systems in the future.

  3. Using convolutional neural networks for human activity classification on micro-Doppler radar spectrograms

    Science.gov (United States)

    Jordan, Tyler S.

    2016-05-01

    This paper presents the findings of using convolutional neural networks (CNNs) to classify human activity from micro-Doppler features. An emphasis on activities involving potential security threats such as holding a gun are explored. An automotive 24 GHz radar on chip was used to collect the data and a CNN (normally applied to image classification) was trained on the resulting spectrograms. The CNN achieves an error rate of 1.65 % on classifying running vs. walking, 17.3 % error on armed walking vs. unarmed walking, and 22 % on classifying six different actions.

  4. Monitoring Surface Deformation in Polar, Alpine, and Plateau Periglacial Environments From Space Using Radar Interferometry

    Science.gov (United States)

    Liu, L.; Zebker, H. A.; Zhang, T.; Westfall, R. D.; Millar, C. I.

    2011-12-01

    Widespread and systematic changes in the permafrost and active layers could have profound effects on biological, biogeochemical, hydrologic, and landscape processes, on the flux of greenhouse gases, and on human infrastructure. Thawing of ice-rich permafrost in alpine areas can lead to rapid mass wasting, including active-layer detachment, retrogressive thaw slumps, rock glacier movement, and even more catastrophic events such as landslides, debris flow, and rock falls. We apply radar interferometry (or InSAR) technique to the Phased Array type L-band Synthetic Aperture Radar (PALSAR) data acquired by the Advanced Land Observing Satellite (ALOS) satellite to monitor changes in permafrost and in the active layer in polar, alpine, and plateau periglacial environments. Using InSAR, we are able to map the surface deformation over large area (typically 70 km by 100 km), at a high spatial resolution up to about 10 m, at an interval as short as 46 days. Specifically, near Deadhorse and Barrow on the Arctic coast of Alaska, we detect seasonal thaw settlement and frost heave of 2 to 4 cm. In the Sierra Nevada of California, we find surface deformation of 5 to 20 cm within three summer months over the Barney Lake and Gibbs rock glaciers. On the Qinghai-Tibet Plateau, we map active layer thaw slumps near the Qinghai-Tibet highway and compare our space-geodetic measurements with ground measurements. Using the radar data acquired by the same sensor, we will compare the spatial and temporal characteristics of these surface motions. We will also present our estimates of long-term trends in surface deformation in the polar and plateau study areas and discuss their associations with increasing ground temperatures. Field data on rock temperatures indicate that active rock glaciers are highly resistant to warming surface temperatures. Therefore, we expect little long-term trends in rock glacier motions.

  5. Evaluation of the HF-Radar network system around Taiwan using normalized cumulative Lagrangian separation.

    Science.gov (United States)

    Fredj, Erick; Kohut, Josh; Roarty, Hugh; Lai, Jian-Wu

    2017-04-01

    The Lagrangian separation distance between the endpoints of simulated and observed drifter trajectories is often used to assess the performance of numerical particle trajectory models. However, the separation distance fails to indicate relative model performance in weak and strong current regions, such as over continental shelves and the adjacent deep ocean. A skill score described in detail by (Lui et.al. 2011) was applied to estimate the cumulative Lagrangian separation distances normalized by the associated cumulative trajectory lengths. In contrast, the Lagrangian separation distance alone gives a misleading result. The proposed dimensionless skill score is particularly useful when the number of drifter trajectories is limited and neither a conventional Eulerian-based velocity nor a Lagrangian based probability density function may be estimated. The skill score assesses The Taiwan Ocean Radar Observing System (TOROS) performance. TOROS consists of 17 SeaSonde type radars around the Taiwan Island. The currents off Taiwan are significantly influenced by the nearby Kuroshio current. The main stream of the Kuroshio flows along the east coast of Taiwan to the north throughout the year. Sometimes its branch current also bypasses the south end of Taiwan and goes north along the west coast of Taiwan. The Kuroshio is also prone to seasonal change in its speed of flow, current capacity, distribution width, and depth. The evaluations of HF-Radar National Taiwanese network performance using Lagrangian drifter records demonstrated the high quality and robustness of TOROS HF-Radar data using a purely trajectory-based non-dimensional index. Yonggang Liu and Robert H. Weisberg, "Evaluation of trajectory modeling in different dynamic regions using normalized cumulative Lagrangian separation", Journal of Geophysical Research, Vol. 116, C09013, doi:10.1029/2010JC006837, 2011

  6. On-Board Fiber-Optic Network Architectures for Radar and Avionics Signal Distribution

    Science.gov (United States)

    Alam, Mohammad F.; Atiquzzaman, Mohammed; Duncan, Bradley B.; Nguyen, Hung; Kunath, Richard

    2000-01-01

    Continued progress in both civil and military avionics applications is overstressing the capabilities of existing radio-frequency (RF) communication networks based on coaxial cables on board modem aircrafts. Future avionics systems will require high-bandwidth on- board communication links that are lightweight, immune to electromagnetic interference, and highly reliable. Fiber optic communication technology can meet all these challenges in a cost-effective manner. Recently, digital fiber-optic communication systems, where a fiber-optic network acts like a local area network (LAN) for digital data communications, have become a topic of extensive research and development. Although a fiber-optic system can be designed to transport radio-frequency (RF) signals, the digital fiber-optic systems under development today are not capable of transporting microwave and millimeter-wave RF signals used in radar and avionics systems on board an aircraft. Recent advances in fiber optic technology, especially wavelength division multiplexing (WDM), has opened a number of possibilities for designing on-board fiber optic networks, including all-optical networks for radar and avionics RF signal distribution. In this paper, we investigate a number of different novel approaches for fiber-optic transmission of on-board VHF and UHF RF signals using commercial off-the-shelf (COTS) components. The relative merits and demerits of each architecture are discussed, and the suitability of each architecture for particular applications is pointed out. All-optical approaches show better performance than other traditional approaches in terms of signal-to-noise ratio, power consumption, and weight requirements.

  7. Introducing Switching Ordered Statistic CFAR Type I in Different Radar Environments

    Directory of Open Access Journals (Sweden)

    Saeed Erfanian

    2009-01-01

    Full Text Available In this paper, a new CFAR detector based on a switching algorithm and OS-CFAR for nonhomogeneous background environments is introduced. The new detector is named Switching Ordered Statistic CFAR type I (SOS CFAR I. The SOS CFAR I selects a set of suitable cells and then with the help of the ordering method, estimates the unknown background noise level. The proposed detector does not require any prior information about the background environment and uses cells with similar statistical specifications to estimate the background noise. The performance of SOS CFAR I is evaluated and compared with other detectors such as CA-CFAR, GO-CFAR, SO-CFAR, and OS-CFAR for the Swerling I target model in homogeneous and nonhomogeneous noise environments such as those with multiple interference and clutter edges. The results show that SOS CFAR I detectors considerably reduce the problem of excessive false alarm probability near clutter edges while maintaining good performance in other environments. Also, simulation results confirm the achievement of an optimum detection threshold in homogenous and nonhomogeneous radar environments by the mentioned processor.

  8. Detection and tracking of human targets in indoor and urban environments using through-the-wall radar sensors

    Science.gov (United States)

    Radzicki, Vincent R.; Boutte, David; Taylor, Paul; Lee, Hua

    2017-05-01

    Radar based detection of human targets behind walls or in dense urban environments is an important technical challenge with many practical applications in security, defense, and disaster recovery. Radar reflections from a human can be orders of magnitude weaker than those from objects encountered in urban settings such as walls, cars, or possibly rubble after a disaster. Furthermore, these objects can act as secondary reflectors and produce multipath returns from a person. To mitigate these issues, processing of radar return data needs to be optimized for recognizing human motion features such as walking, running, or breathing. This paper presents a theoretical analysis on the modulation effects human motion has on the radar waveform and how high levels of multipath can distort these motion effects. From this analysis, an algorithm is designed and optimized for tracking human motion in heavily clutter environments. The tracking results will be used as the fundamental detection/classification tool to discriminate human targets from others by identifying human motion traits such as predictable walking patterns and periodicity in breathing rates. The theoretical formulations will be tested against simulation and measured data collected using a low power, portable see-through-the-wall radar system that could be practically deployed in real-world scenarios. Lastly, the performance of the algorithm is evaluated in a series of experiments where both a single person and multiple people are moving in an indoor, cluttered environment.

  9. A Novel Anti-Stealth Technique Based on Stratospheric Balloon-Borne Radar in Heterogeneous Environments

    Science.gov (United States)

    Barbary, Mohamed; Zong, Peng

    2015-05-01

    Radar cross section (RCS) of a stealth target model like F-117A can be improved by multichannel stratospheric balloon-borne bistatic radar at higher aspect angle. The potential problem is that the stealth target may produce range walk in clutter heterogeneous environments, thus it is difficult to determine the range ambiguity under quadratic range cell migration (QRCM). In this paper, a novel detection technique known as hybrid modified fractional-radon Fourier transform (MFrRFT) and knowledge-aided space-time adaptive processes (KA-STAP) is proposed to impact this kind of problem simultaneously. KA-STAP is applied to suppress the non-homogeneous clutter in the received data, and MFrRFT is used to eliminate the QRCM along with the second-order keystone transform (SOKT), so as to estimate the range ambiguity and compensate the stealth target's range walk. The hybrid MFrRFT/KA-STAP scheme is simple and applicable to the small RCS of fast stealth target with a long-time coherent integration. Finally, to achieve high accuracy of locating stealth target, a non-parametric detection technique based on Legendre orthogonal polynomials is applied to reconstruct the probability density function (pdf) of real RCS data predicted by physical optics (PO) approximation method.

  10. Requirements for a Network Storage Service in a supercomputer environment

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, S.M.

    1991-09-26

    Sandia National Laboratories has completed a requirements study for a networked mass storage system. The areas of user functionality, network connectivity, and performance were analyzed to determine specifications for a Network Storage Service to operate in supercomputer environment. 4 refs.

  11. MARSnet: Mission-aware Autonomous Radar Sensor Network for Future Combat Systems 12/8/06 to 12/31/09

    Science.gov (United States)

    2010-01-01

    or West Virginia Sago mine disaster in January 2006, cognitive radar sensor network-based information integration for first responders is critical for...disaster scenario, such as Utah Mine Collapse in August 2007 or West Virginia Sago mine disaster in January 2006, radar sensor network-based information

  12. Dynamic Optical Networks for Future Internet Environments

    Science.gov (United States)

    Matera, Francesco

    2014-05-01

    This article reports an overview on the evolution of the optical network scenario taking into account the exponential growth of connected devices, big data, and cloud computing that is driving a concrete transformation impacting the information and communication technology world. This hyper-connected scenario is deeply affecting relationships between individuals, enterprises, citizens, and public administrations, fostering innovative use cases in practically any environment and market, and introducing new opportunities and new challenges. The successful realization of this hyper-connected scenario depends on different elements of the ecosystem. In particular, it builds on connectivity and functionalities allowed by converged next-generation networks and their capacity to support and integrate with the Internet of Things, machine-to-machine, and cloud computing. This article aims at providing some hints of this scenario to contribute to analyze impacts on optical system and network issues and requirements. In particular, the role of the software-defined network is investigated by taking into account all scenarios regarding data centers, cloud computing, and machine-to-machine and trying to illustrate all the advantages that could be introduced by advanced optical communications.

  13. Utilizing Q-Learning to allow a radar to choose its transmit frequency, adapting to its environment

    CSIR Research Space (South Africa)

    Wabeke, LO

    2010-06-01

    Full Text Available loop manner could seem to be cognitive of its environment, able to adapt to changes to optimize performance. Reinforced learning could play a vital role as part of such a closed-loop cognitive radar system. The Q-Learning algorithm is hypothesized...

  14. Report on Asian Environment Information Network; 'Asia kankyo joho network' ni kansuru hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    The goal is the construction of Asian Environment Information Network (AEInet) in accordance with a contract signed between Indonesia's LIPI (Indonesian Institute of Science) and NEDO under NEDO's Research Cooperation Project Concerning the Development of Environment Measuring Laser Radar (LR). The network is so designed and constituted as to operate on a private line between Indonesia and Japan via IP (Internet protocol) and to enable the exchange on the Internet network of the data collected/analyzed by the Indonesian LR system and of articles of e-mail between scientists of the two countries. The AEInet will be utilized for the collection/analysis of LR-collected data; exchange of observed data and the result of processing; provision of support to environment information scientists in exchanging e-mail and information; and the search of databases for the implementation of the project. In this paper, the outline and functions of the system, network system design, WWW server construction, network operating status, joint researches with Indonesia, etc., are described. (NEDO)

  15. Radar subpixel-scale rainfall variability and uncertainty: lessons learned from observations of a dense rain-gauge network

    Directory of Open Access Journals (Sweden)

    N. Peleg

    2013-06-01

    Full Text Available Runoff and flash flood generation are very sensitive to rainfall's spatial and temporal variability. The increasing use of radar and satellite data in hydrological applications, due to the sparse distribution of rain gauges over most catchments worldwide, requires furthering our knowledge of the uncertainties of these data. In 2011, a new super-dense network of rain gauges containing 14 stations, each with two side-by-side gauges, was installed within a 4 km2 study area near Kibbutz Galed in northern Israel. This network was established for a detailed exploration of the uncertainties and errors regarding rainfall variability within a common pixel size of data obtained from remote sensing systems for timescales of 1 min to daily. In this paper, we present the analysis of the first year's record collected from this network and from the Shacham weather radar, located 63 km from the study area. The gauge–rainfall spatial correlation and uncertainty were examined along with the estimated radar error. The nugget parameter of the inter-gauge rainfall correlations was high (0.92 on the 1 min scale and increased as the timescale increased. The variance reduction factor (VRF, representing the uncertainty from averaging a number of rain stations per pixel, ranged from 1.6% for the 1 min timescale to 0.07% for the daily scale. It was also found that at least three rain stations are needed to adequately represent the rainfall (VRF < 5% on a typical radar pixel scale. The difference between radar and rain gauge rainfall was mainly attributed to radar estimation errors, while the gauge sampling error contributed up to 20% to the total difference. The ratio of radar rainfall to gauge-areal-averaged rainfall, expressed by the error distribution scatter parameter, decreased from 5.27 dB for 3 min timescale to 3.21 dB for the daily scale. The analysis of the radar errors and uncertainties suggest that a temporal scale of at least 10 min should be used for

  16. Estimation of convective precipitation: the meteorological radar versus an automatic rain gauge network

    Directory of Open Access Journals (Sweden)

    M. C. Llasat

    2005-01-01

    Full Text Available The estimation of convective precipitation and its contribution to total precipitation is an important issue both in hydrometeorology and radio links. The greatest part of this kind of precipitation is related with high intensity values that can produce floods and/or damage and disturb radio propagation. This contribution proposes two approaches for the estimation of convective precipitation, using the β parameter that is related with the greater or lesser convective character of the precipitation event, and its time and space distribution throughout the entire series of the samples. The first approach was applied to 126 rain gauges of the Automatic System of Hydrologic Information of the Internal Basins of Catalonia (NE Spain. Data are series of 5-min rain rate, for the period 1996-2002, and a long series of 1-min rain rate starting in 1927. Rainfall events were classified according to this parameter. The second approach involved using information obtained by the meteorological radar located near Barcelona. A modified version of the SCIT method for the 3-D analysis and a combination of different methods for the 2-D analysis were applied. Convective rainfall charts and β charts were reported. Results obtained by the rain gauge network and by the radar were compared. The application of the β parameter to improve the rainfall regionalisation was demonstrated.

  17. Application of Deep Networks to Oil Spill Detection Using Polarimetric Synthetic Aperture Radar Images

    Directory of Open Access Journals (Sweden)

    Guandong Chen

    2017-09-01

    Full Text Available Polarimetric synthetic aperture radar (SAR remote sensing provides an outstanding tool in oil spill detection and classification, for its advantages in distinguishing mineral oil and biogenic lookalikes. Various features can be extracted from polarimetric SAR data. The large number and correlated nature of polarimetric SAR features make the selection and optimization of these features impact on the performance of oil spill classification algorithms. In this paper, deep learning algorithms such as the stacked autoencoder (SAE and deep belief network (DBN are applied to optimize the polarimetric feature sets and reduce the feature dimension through layer-wise unsupervised pre-training. An experiment was conducted on RADARSAT-2 quad-polarimetric SAR image acquired during the Norwegian oil-on-water exercise of 2011, in which verified mineral, emulsions, and biogenic slicks were analyzed. The results show that oil spill classification achieved by deep networks outperformed both support vector machine (SVM and traditional artificial neural networks (ANN with similar parameter settings, especially when the number of training data samples is limited.

  18. Detection of small targets in a marine environment using laser radar

    NARCIS (Netherlands)

    Kunz, G.J.; Bekman, H.H.P.T.; Benoist, K.W.; Cohen, L.H.; Heuvel, J.C. van den; Putten, F.J.M.

    2005-01-01

    Small maritime targets, e.g., periscope tubes, jet skies, swimmers and small boats, are potential threats for naval ships under many conditions, but are difficult to detect with current radar systems due to their limited radar cross section and the presence of sea clutter. On the other hand,

  19. Amigo - Ambient Intelligence for the networked home environment

    NARCIS (Netherlands)

    Janse, M.D.

    2008-01-01

    The Amigo project develops open, standardized, interoperable middleware and attractive user services for the networked home environment. Fifteen of Europe's leading companies and research organizations in mobile and home networking, software development, consumer electronics and domestic appliances

  20. Using radar ground-truth to validate and improve the location accuracy of a lightning direction-finding network

    Science.gov (United States)

    Goodman, Steven J.

    1989-01-01

    A technique is described in which isolated radar echoes associated with clusters of lightning strikes are used to validate and improve the location accuracy of a lightning-direction-finding network. Using this technique, site errors of a magnetic direction-finding network for locating lightning strikes to ground were accurately determined. The technique offers advantages over existing techniques in that large sample sizes are readily attainable over a broad area on a regular basis; the technique can also provide additional constraints to redundant data methods such as that described by Orville (1987). Since most lightning strike networks have either partial or full weather radar coverage, the technique is practical for all but a few users.

  1. Vertical air motion retrievals in deep convective clouds using the ARM scanning radar network in Oklahoma during MC3E

    Science.gov (United States)

    North, Kirk W.; Oue, Mariko; Kollias, Pavlos; Giangrande, Scott E.; Collis, Scott M.; Potvin, Corey K.

    2017-08-01

    The US Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) program's Southern Great Plains (SGP) site includes a heterogeneous distributed scanning Doppler radar network suitable for collecting coordinated Doppler velocity measurements in deep convective clouds. The surrounding National Weather Service (NWS) Next Generation Weather Surveillance Radar 1988 Doppler (NEXRAD WSR-88D) further supplements this network. Radar velocity measurements are assimilated in a three-dimensional variational (3DVAR) algorithm that retrieves horizontal and vertical air motions over a large analysis domain (100 km × 100 km) at storm-scale resolutions (250 m). For the first time, direct evaluation of retrieved vertical air velocities with those from collocated 915 MHz radar wind profilers is performed. Mean absolute and root-mean-square differences between the two sources are of the order of 1 and 2 m s-1, respectively, and time-height correlations are of the order of 0.5. An empirical sensitivity analysis is done to determine a range of 3DVAR constraint weights that adequately satisfy the velocity observations and anelastic mass continuity. It is shown that the vertical velocity spread over this range is of the order of 1 m s-1. The 3DVAR retrievals are also compared to those obtained from an iterative upwards integration technique. The results suggest that the 3DVAR technique provides a robust, stable solution for cases in which integration techniques have difficulty satisfying velocity observations and mass continuity simultaneously.

  2. An Operative X-band Mini-radar Network to Monitor Rainfall Events with High Time and Space Resolution

    Directory of Open Access Journals (Sweden)

    S. Bertoldo

    2012-08-01

    Full Text Available The increasing frequency of extreme and very localized precipitation events have been causing landslides, floods and casualties, especially in Sicily, due to its complex orography, and to the presence of densely inhabited areas just at the mouth of small basins. In order to monitor such phenomena with the needed high resolution in time and space, an experimental network of X-band mini-radars, exclusively devoted to monitor rain, has been installed in some parts of Sicily since November 2010. The network is made up by 4 mini weather radars able to acquire a rain map every minute (or even at shorter intervals with a radial space resolution better than 100 m within a range of up to 30 km. Their low cost and the easiness of installation make such radars ideal for monitoring small areas or even just limited angular sectors, since it is more convenient to install more than one instrument instead of choosing special site locations or spending for installation support. The raw data are immediately processed in real time by the software installed on each radar unit, Cartesian maps are locally produced, compressed and transmitted via GPRS to a server where ad hoc products for the users are prepared and made available on a web site. A few examples of final products and some comparisons with rain gauges are presented.

  3. Report of findings: Contaminant study of the environment surrounding the Cape Romanzof Long Range Radar Site

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Cape Romanzof Long Range Radar Site (Cape Romanzof) contains many petroleum-related spills and hazardous substances. Therefore, in 1987 and 1988 a field study...

  4. A Novel Data-Driven Learning Method for Radar Target Detection in Nonstationary Environments

    Science.gov (United States)

    2016-05-01

    performance compared with detec- tion techniques that are not aware of the environmental changes. Index Terms—Active drift learning, cognitive radar, data...methods to identify the distribution of the radar measurements using a prelearned dictionary of possible probability density functions (pdfs) representing...clutter and noise processes; 2) A dictionary of possi- ble pdfs is assumed to exist; and 3) The problem of estimating the time instant when the statistical

  5. Security Technologies for Open Networking Environments (STONE)

    Energy Technology Data Exchange (ETDEWEB)

    Muftic, Sead

    2005-03-31

    Under this project SETECS performed research, created the design, and the initial prototype of three groups of security technologies: (a) middleware security platform, (b) Web services security, and (c) group security system. The results of the project indicate that the three types of security technologies can be used either individually or in combination, which enables effective and rapid deployment of a number of secure applications in open networking environments. The middleware security platform represents a set of object-oriented security components providing various functions to handle basic cryptography, X.509 certificates, S/MIME and PKCS No.7 encapsulation formats, secure communication protocols, and smart cards. The platform has been designed in the form of security engines, including a Registration Engine, Certification Engine, an Authorization Engine, and a Secure Group Applications Engine. By creating a middleware security platform consisting of multiple independent components the following advantages have been achieved - Object-oriented, Modularity, Simplified Development, and testing, Portability, and Simplified extensions. The middleware security platform has been fully designed and a preliminary Java-based prototype has been created for the Microsoft Windows operating system. The Web services security system, designed in the project, consists of technologies and applications that provide authentication (i.e., single sign), authorization, and federation of identities in an open networking environment. The system is based on OASIS SAML and XACML standards for secure Web services. Its topology comprises three major components: Domain Security Server (DSS) is the main building block of the system Secure Application Server (SAS) Secure Client In addition to the SAML and XACML engines, the authorization system consists of two sets of components An Authorization Administration System An Authorization Enforcement System Federation of identities in multi

  6. Wireless sensor networks in a maritime environment.

    NARCIS (Netherlands)

    Kavelaars, W.; Maris, M.

    2005-01-01

    In the recent years, there has been a lot of research on sensor networks-and their applications. In particular for monitoring large and potentially hostile areas these networks have proven to be very useful. The technique of land-based sensor networks can be extrapolated to sensing buoys at sea or

  7. Parallel Evolutionary Peer-to-Peer Networking in Realistic Environments

    Directory of Open Access Journals (Sweden)

    Kei Ohnishi

    2017-01-01

    Full Text Available In the present paper we first conduct simulations of the parallel evolutionary peer-to-peer (P2P networking technique (referred to as P-EP2P that we previously proposed using models of realistic environments to examine if P-EP2P is practical. Environments are here represented by what users have and want in the network, and P-EP2P adapts the P2P network topologies to the present environment in an evolutionary manner. The simulation results show that P-EP2P is hard to adapt the network topologies to some realistic environments. Then, based on the discussions of the results, we propose a strategy for better adaptability of P-EP2P to the realistic environments. The strategy first judges if evolutionary adaptation of the network topologies is likely to occur in the present environment, and if it judges so, it actually tries to achieve evolutionary adaptation of the network topologies. Otherwise, it brings random change to the network topologies. The simulation results indicate that P-EP2P with the proposed strategy can better adapt the network topologies to the realistic environments. The main contribution of the study is to present such a promising way to realize an evolvable network in which the evolution direction is given by users.

  8. Mobility management for SIP sessions in a heterogeneous network environment

    NARCIS (Netherlands)

    Romijn, Willem A.; Plas, Dirk-Jaap; Bijwaard, D.; Meeuwissen, Erik; van Ooijen, Gijs

    2004-01-01

    The next generation of communication networks is expected to create a heterogeneous network environment encompassing an ever-increasing number of different access networks and end-user terminals that will enable the introduction of and provide access to numerous feature-rich end-user services. It is

  9. An operative X-band mini-radar network to monitor rainfall events with high time and space resolution

    OpenAIRE

    S. Bertoldo; C. Lucianaz; Allegretti, M.; Rorato, O.; A. Prato; Perona, G.

    2012-01-01

    The increasing frequency of extreme and very localized precipitation events have been causing landslides, floods and casualties, especially in Sicily, due to its complex orography, and to the presence of densely inhabited areas just at the mouth of small basins. In order to monitor such phenomena with the needed high resolution in time and space, an experimental network of X-band mini-radars, exclusively devoted to monitor rain, has been installed in some parts of Sicily since November 2010. ...

  10. Cut-off low monitoring by the French VHF-ST-radar network during the ESTIME campaign

    Science.gov (United States)

    Caccia, J.-L.; Bertin, F.; Campistron, B.; Klaus, V.; Pointin, Y.; van Baelen, J.; Wilson, R.

    2000-05-01

    In order to investigate mesoscale strato-tropospheric exchanges, the field campaign `Echanges Stratosphère-Troposphère: Investigations à Moyenne Echelle' was conducted in France from late 1993 to mid 1995 and focused on cut-off low events. It involved the French research network of five VHF (Very High Frequency) ST (Strato-Tropospheric) radars deployed in southern France. Observations corresponding to three Intensive Observing Periods are reported here. The radar data analyzed and discussed are time-height diagrams of the aspect ratio (AR), that is, the vertical to oblique beam-returned power ratio, used for monitoring three cut-off low events. In order to discuss the validity of the method, 506 h of radar AR data were compared with time-height diagrams of the static stability and the humidity obtained from synoptic European Center for Medium-range Weather Forecasts model analyses. A dataset corresponding to 297 h of observations is analyzed and discussed here. It is concluded that the AR is a good tracer to document cut-off low events, including tropopause folding identification and the detection of tropospheric air masses of enhanced stability, in dry or weakly humid cases. On the other hand, although the effects of the specific humidity and its gradients on VHF radar echo power could not be extensively investigated, our results suggest that the same parameter cannot be used at mid- and lower-tropospheric levels when the effects of specific humidity significantly reinforce the moist static stability. It is important to take into account these insights in the context of future observing campaigns in which a network of VHF-ST-radars will be involved, and where their role will be to observe and to document the evolution of upper-level features or potential vorticity streamers, or more generally stratospheric-tropospheric exchanges.

  11. Radar cross section of dipole phased arrays with parallel feed network

    CERN Document Server

    Singh, Hema; Jha, Rakesh Mohan

    2016-01-01

    This book presents the detailed analytical formulation for the RCS of parallel-fed linear dipole array in the presence of mutual coupling. The radar cross section (RCS) of an object represents its electromagnetic (EM) scattering properties for a given incident wave. The analysis of scattered field is critical in military and defence arenas, especially while designing low-observable platforms. It is well-known that the presence of an antenna/array on the target influences its echo area significantly. The primary cause for such scattering of the incident signals is reflection that occurs within the antenna aperture and its feed network. In this book, the RCS estimation is done based on the signal path within the antenna system. The scattered field is expressed in terms of array design parameters including the reflection and transmission coefficients. The computed results show the variation in the RCS pattern with and without mutual coupling. The effect of finite dipole-length, inter-element spacing, scan angle,...

  12. ABORT-like detector to combat active deceptive jamming in a network of LFM radars

    Directory of Open Access Journals (Sweden)

    Yuan ZHAO

    2017-08-01

    Full Text Available This paper studies an electronic counter-counter measures (ECCM scheme combating against deceptive electronic counter measure (ECM techniques. An adaptive detector exploiting generalized likelihood ratio test (GRLT criterion is applied to detect the presence of deceptive jamming in fractional Fourier transform (FrFT domain. First, the generating mechanism of spurious frequencies is analyzed based on the Volterra serial. The proposed nonlinear distortion model based on power amplifier behavior is robust in distortion analysis when the memory effect is considered. Second, a modified adaptive beamformer orthogonal rejection test (ABORT like detector in closed form is built. The proposed detector can discriminate the echo and deceptive jamming adaptively by exploiting primary data and secondary data. This ECCM scheme is capable of guaranteeing the performance without the restriction of orthogonality, which is essential for the ABORT detectors. The expansion to radar network is discussed as a special case at the final part of this paper. Numerical simulations demonstrate the effectiveness of the proposed method.

  13. Radar cross-section measurements of ice particles using vector network analyzer

    Directory of Open Access Journals (Sweden)

    Jinhu Wang

    2016-09-01

    Full Text Available We carried out radar cross-section (RSC measurements of ice particles in a microwave anechoic chamber at Nanjing University of Information Science and Technology. We used microwave similarity theory to enlarge the size of particle from the micrometer to millimeter scale and to reduce the testing frequency from 94 GHz to 10 GHz. The microwave similarity theory was validated using the method of moments for single metal sphere, single dielectric sphere, and spherical and non-spherical dielectric particle swarms. The differences between the retrieved and theoretical results at 94 GHz were 0.016117%, 0.0023029%, 0.027627%, and 0.0046053%, respectively. We proposed a device that can measure the RCS of ice particles in the chamber based on the S21 parameter obtained from vector network analyzer. On the basis of the measured S21 parameter of the calibration material (metal plates and their corresponding theoretical RCS values, the RCS values of a spherical Teflon particle swarm and cuboid candle particle swarm was retrieved at 10 GHz. In this case, the differences between the retrieved and theoretical results were 12.72% and 24.49% for the Teflon particle swarm and cuboid candle swarm, respectively.

  14. A spatial daily rainfall model for interpolation of raingauge networks using artificial radar fields, for realistic hydrological modelling

    Science.gov (United States)

    Pegram, Geoff; Gyasi-Agyei, Yeboah

    2014-05-01

    The inherent patchiness and intermittency of daily rainfall make interpolation of sparse point measurements over a catchment very challenging. Usual methods of interpolation of daily rainfall vary from simple numerical averaging through the use of Thiessen polygons to advanced statistical methods such as Kriging. This presentation treats the interpolation problem by conditioning plausible replicas of radar-rainfields on to the point observations and examines the effectiveness of the process by cross-validation. The issues addressed include: * we use Kriging but we first Gaussianise the point rainfall data with special treatment of the zeros to eliminate skewness * Kriging gives us estimates of error in the Gaussian domain to show how good/bad are the interpolations and also offers the standard deviation at each pixel in the field * we choose the form of the [co]variogram to be used in Kriging so as to mimic nature, by using spatial observations given us by radar * the spatial structure of radar rainfall images is peculiar to the accumulation time: instantaneous radar images do not have appreciable spatial anisotropy * by contrast, morphed hourly and daily accumulations of radar images exhibit strong spatial anisotropy * we determine the characteristics of the daily accumulations of radar rainfall and find the spatial correlogram characteristics [orientation, range and ratio of minor to major axes] in the chosen region are strongly related to the radar wetted area ratio: RWAR * to proceed, we simulate correlograms for the chosen day based on the RWAR which is related to the gauge wetness ratio * simulate Gaussian radar fields based on the RWAR with the same variance as the Kriged interpolations of the point values and conditionally merge them with the gauge values, be they observations or simulations * to evaluate the worth of the process, we perform cross-validation of spatial field estimates against gauge values in 'leave-one-out' exercises * the methodology is

  15. Hardware in the loop radar environment simulation on wideband DRFM platforms

    CSIR Research Space (South Africa)

    Strydom, JJ

    2012-10-01

    Full Text Available into the VME rack. Alternatively the clutter channel can be reprogrammed through the GUI to fulfil one of these tasks. The modular design of the DRFM kernel makes the HIL RES highly configurable. 4 Complex Targets Modern radars increasingly exploit..., M. Diani, and L. Verrazzani ?Performance Analysis of Two Adaptive Radar Detectors against Non-Gaussian Real Sea Clutter Data,? IEEE Trans. on Aerospace and Electronic Systems , Vol. 36, No. 4, October 2000, pp. 1429-1439. [5] P. L. Herselman...

  16. Wireless sensor networks in a maritime environment

    Science.gov (United States)

    Kavelaars, W.; Maris, M.

    2005-10-01

    In the recent years, there has been a lot of research on sensor networks and their applications. In particular for monitoring large and potentially hostile areas these networks have proven to be very useful. The technique of land-based sensor networks can be extrapolated to sensing buoys at sea or in harbors. This is a novel and intriguing addition to existing maritime monitoring systems. At TNO, much research effort has gone into developing sensor networks. In this paper, the TNOdes sensor network is presented. Its practical employability is demonstrated in a surveillance application deploying 50 nodes. The system is capable of tracking persons in a field, as would be the situation around a military compound. A camera-system is triggered by the sensors and zooms into the detected moving objects. It is described how this system could be modified to create a wireless buoys network. Typical applications of a wireless (and potentially mobile) buoy network are bay-area surveillance, mine detection, identification and ship protection.

  17. EXTRACTING A RADAR REFLECTION FROM A CLUTTERED ENVIRONMENT USING 3-D INTERPRETATION

    Science.gov (United States)

    A 3-D Ground Penetrating Radar (GPR) survey at 50 MHz center frequency was conducted at Hill Air Force Base, Utah, to define the topography of the base of a shallow aquifer. The site for the survey was Chemical Disposal Pit #2 where there are many man-made features that generate ...

  18. Optimization of neural network architecture for classification of radar jamming FM signals

    Science.gov (United States)

    Soto, Alberto; Mendoza, Ariadna; Flores, Benjamin C.

    2017-05-01

    The purpose of this study is to investigate several artificial Neural Network (NN) architectures in order to design a cognitive radar system capable of optimally distinguishing linear Frequency-Modulated (FM) signals from bandlimited Additive White Gaussian Noise (AWGN). The goal is to create a theoretical framework to determine an optimal NN architecture to achieve a Probability of Detection (PD) of 95% or higher and a Probability of False Alarm (PFA) of 1.5% or lower at 5 dB Signal to Noise Ratio (SNR). Literature research reveals that the frequency-domain power spectral densities characterize a signal more efficiently than its time-domain counterparts. Therefore, the input data is preprocessed by calculating the magnitude square of the Discrete Fourier Transform of the digitally sampled bandlimited AWGN and linear FM signals to populate a matrix containing N number of samples and M number of spectra. This matrix is used as input for the NN, and the spectra are divided as follows: 70% for training, 15% for validation, and 15% for testing. The study begins by experimentally deducing the optimal number of hidden neurons (1-40 neurons), then the optimal number of hidden layers (1-5 layers), and lastly, the most efficient learning algorithm. The training algorithms examined are: Resilient Backpropagation, Scaled Conjugate Gradient, Conjugate Gradient with Powell/Beale Restarts, Polak-Ribiére Conjugate Gradient, and Variable Learning Rate Backpropagation. We determine that an architecture with ten hidden neurons (or higher), one hidden layer, and a Scaled Conjugate Gradient for training algorithm encapsulates an optimal architecture for our application.

  19. Smart Sensor Network System For Environment Monitoring

    Directory of Open Access Journals (Sweden)

    Javed Ali Baloch

    2012-07-01

    Full Text Available SSN (Smart Sensor Network systems could be used to monitor buildings with modern infrastructure, plant sites with chemical pollution, horticulture, natural habitat, wastewater management and modern transport system. To sense attributes of phenomena and make decisions on the basis of the sensed value is the primary goal of such systems. In this paper a Smart Spatially aware sensor system is presented. A smart system, which could continuously monitor the network to observe the functionality and trigger, alerts to the base station if a change in the system occurs and provide feedback periodically, on demand or even continuously depending on the nature of the application. The results of the simulation trials presented in this paper exhibit the performance of a Smart Spatially Aware Sensor Networks.

  20. A Novel Low-Cost Dual-Wavelength Precipitation Radar Sensor Network Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Remote Sensing Solutions, Inc. (RSS) has developed a novel, practical design that will produce a low-cost precipitation radar / radiometer sensor. Operating in a...

  1. Home-Network Security Model in Ubiquitous Environment

    OpenAIRE

    Dong-Young Yoo; Jong-Whoi Shin; Jin-Young Choi

    2007-01-01

    Social interest and demand on Home-Network has been increasing greatly. Although various services are being introduced to respond to such demands, they can cause serious security problems when linked to the open network such as Internet. This paper reviews the security requirements to protect the service users with assumption that the Home-Network environment is connected to Internet and then proposes the security model based on the requirement. The proposed security mode...

  2. Managing the Environment : Effects of network ambition on agency performance

    NARCIS (Netherlands)

    Akkerman, A.; Torenvlied, R.

    2011-01-01

    The literature on network management in the public sector reports positive effects of network activity on agency performance. Current studies show however no differences between specific types of contacts in an agency's environment. The present article adopts an explorative design to study the

  3. Mobile Sensor Networks for Inspection Tasks in Harsh Industrial Environments

    NARCIS (Netherlands)

    Mulder, Jacob; Wang, Xinyu; Ferwerda, Franke; Cao, Ming

    Recent advances in sensor technology have enabled the fast development of mobile sensor networks operating in various unknown and sometimes hazardous environments. In this paper, we introduce one integrative approach to design, analyze and test distributed control algorithms to coordinate a network

  4. Crowdsourcing the nodulation gene network discovery environment.

    Science.gov (United States)

    Li, Yupeng; Jackson, Scott A

    2016-05-26

    The Legumes (Fabaceae) are an economically and ecologically important group of plant species with the conspicuous capacity for symbiotic nitrogen fixation in root nodules, specialized plant organs containing symbiotic microbes. With the aim of understanding the underlying molecular mechanisms leading to nodulation, many efforts are underway to identify nodulation-related genes and determine how these genes interact with each other. In order to accurately and efficiently reconstruct nodulation gene network, a crowdsourcing platform, CrowdNodNet, was created. The platform implements the jQuery and vis.js JavaScript libraries, so that users are able to interactively visualize and edit the gene network, and easily access the information about the network, e.g. gene lists, gene interactions and gene functional annotations. In addition, all the gene information is written on MediaWiki pages, enabling users to edit and contribute to the network curation. Utilizing the continuously updated, collaboratively written, and community-reviewed Wikipedia model, the platform could, in a short time, become a comprehensive knowledge base of nodulation-related pathways. The platform could also be used for other biological processes, and thus has great potential for integrating and advancing our understanding of the functional genomics and systems biology of any process for any species. The platform is available at http://crowd.bioops.info/ , and the source code can be openly accessed at https://github.com/bioops/crowdnodnet under MIT License.

  5. Radar rainfall estimates in an alpine environment using inverse hydrological modelling

    Directory of Open Access Journals (Sweden)

    A. Marx

    2006-01-01

    Full Text Available The quality of hydrological modelling is limited due to the restricted availability of high resolution temporal and spatial input data such as temperature, global radiation, and precipitation. Radar-based rain measurements provide good spatial information. On the other hand, using radar data is accompanied by basic difficulties such as clutter, shielding, variations of Z/R-relationships, beam-resolution and attenuation. Instead of accounting for all errors involved separately, a robust Z/R-relationship is estimated in this study for the short range (up to 40 km distance using inverse hydrological modelling for a continuous period of three months in summer 2001. River gauge measurements from catchment sizes around 100 km2 are used to estimate areal precipitation and finally Z/R-relationships using a calibrated hydrological model. The study is performed in the alpine Ammer catchment with very short reaction times of the river gauges to rainfall events.

  6. Radar Signature Calculation Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: The calculation, analysis, and visualization of the spatially extended radar signatures of complex objects such as ships in a sea multipath environment and...

  7. Modeling the interactions between the ocean and the environment for microwave radar sensing

    Science.gov (United States)

    Weissman, David E.

    1987-01-01

    An extensive set of X-band microwave backscatter measurements has been analyzed to determine its dependence on winds near the surface, atmospheric stability, and long-wave slopes. These radar measurements, made from a tower in the Gulf of Mexico, were performed in conjunction with an extensive set of simultaneous environmental measurements. The CW microwave system operated at an incidence angle of 45 deg, with antennas directed into winds and waves. Model functions for the radar cross section (RCS) and the modulation transfer function (MTF) are developed that depend on the geophysical variables, including wind stress. Statistical analysis shows that these models functions yield a significant smaller error when fit to the RCS data than a simple wind-speed function displays. A Taylor-series expansion of the returned power from a small area provides a unified function that demonstrates the complementary roles of wave slope and atmospheric fluctuations on both the RCS, the MTF, and the coherence. The issue of linearity of the MTF is addressed with this data set, yielding evidence that this is a valid assumption. These results have direct application to the remote sensing of the mean and fluctuating winds, and the wave spectrum with coherent and incoherent active radars.

  8. SOCIAL NETWORKS AS THE ENVIRONMENT EDUCATION

    Directory of Open Access Journals (Sweden)

    Wojsław Czupryński

    2016-12-01

    Full Text Available The emergence of the global Internet has changed the way the entire human population communicates. The internet has become a platform, where human societies build their lives, and traditional communication over the last few years has been replaced by social networks. Today, social networks are the subject of many debates concerning their advantages, disadvantages and the ideas of what they bring to the future. Portals are not only the way of communication, fun, an idea to spend free time, but also source of social and humanistic knowledge too. Against that, social media could be a huge risk for those who use them. The assigned job above discusses about the topic the detrimental effect what the social networks bring. A series of deviant behaviors caused by use of the portal is also presented in this report. Often they become a dysfunctional generator of actions that manifest themselves among the youth. Consequently, there was a need to take action to stop the growth of this phenomenon among young people. First of all the primary activities at this level are prevention and education in the family.

  9. Effects of Using High-Density Rain Gauge Networks and Weather Radar Data on Urban Hydrological Analyses

    Directory of Open Access Journals (Sweden)

    Seong-Sim Yoon

    2017-11-01

    Full Text Available Flood prediction is difficult in urban areas because only sparse gauge data and radar data of low accuracy are usually used to analyze flooding and inundation. Sub-basins of urban areas are extremely small, so rainfall data of high spatial resolution are required for analyzing complex drainage systems with high spatial variability. This study aimed to produce three types of quantitative precipitation estimation (QPE products using rainfall data that was derived from 190 gauges, including the new high-density rain-gauge network operated by the SK Planet company, and the automated weather stations of the Korea Meteorological Administration, along with weather radar data. This study also simulated urban runoff for the Gangnam District of Seoul, South Korea, using the obtained QPE products to evaluate hydraulic and hydrologic impacts according to three rainfall fields. The accuracy of this approach was assessed in terms of the amount and spatial distribution of rainfall in an urban area. The QPE products provided highly accurate results and simulations of peak runoff and overflow phenomena. They also accurately described the spatial variability of the rainfall fields. Overall, the integration of high-density gauge data with radar data proved beneficial for quantitative rainfall estimation.

  10. Implementation and validation of the ISMAR High Frequency Coastal Radar Network in the Gulf of Manfredonia (Mediterranean Sea)

    DEFF Research Database (Denmark)

    Corgnati, Lorenzo; Mantovani, Carlo; Griffa, Annalisa

    2017-01-01

    Current Profiler (ADCP) during winter 2015, in order to gain information on the correlation between surface and water column velocities. This information is especially relevant for fishery and coastal management applications, where transport of larvae, sediments and pollutants in the water columns...... are considered. Results show that, at least in the considered period, the velocity in the water column is well correlated, and there is a good agreement between surface HF radar and ADCP data (correlations between 0.95 - 0.75). The Gulf of Manfredonia network has been instrumental to the set up of a core...

  11. Conditions for Productive Learning in Network Learning Environments

    DEFF Research Database (Denmark)

    Ponti, M.; Dirckinck-Holmfeld, Lone; Lindström, B.

    2004-01-01

    The Kaleidoscope1 Jointly Executed Integrating Research Project (JEIRP) on Conditions for Productive Networked Learning Environments is developing and elaborating conceptual understandings of Computer Supported Collaborative Learning (CSCL) emphasizing the use of cross-cultural comparative......: Pedagogical design and the dialectics of the digital artefacts, the concept of collaboration, ethics/trust, identity and the role of scaffolding of networked learning environments.   The JEIRP is motivated by the fact that many networked learning environments in various European educational settings...... are designed without a deep understanding of the pedagogical, communicative and collaborative conditions embedded in networked learning. Despite the existence of good theoretical views pointing to a social understanding of learning, rather than a traditional individualistic and information processing approach...

  12. Uncoupled Analysis of Stochastic Reaction Networks in Fluctuating Environments

    Science.gov (United States)

    Zechner, Christoph; Koeppl, Heinz

    2014-01-01

    The dynamics of stochastic reaction networks within cells are inevitably modulated by factors considered extrinsic to the network such as, for instance, the fluctuations in ribosome copy numbers for a gene regulatory network. While several recent studies demonstrate the importance of accounting for such extrinsic components, the resulting models are typically hard to analyze. In this work we develop a general mathematical framework that allows to uncouple the network from its dynamic environment by incorporating only the environment's effect onto the network into a new model. More technically, we show how such fluctuating extrinsic components (e.g., chemical species) can be marginalized in order to obtain this decoupled model. We derive its corresponding process- and master equations and show how stochastic simulations can be performed. Using several case studies, we demonstrate the significance of the approach. PMID:25473849

  13. Networked Mobilities and Performative Urban Environments

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    Physical mobility has an important cultural dimension to contemporary life. The movement of objects, signs, and people constitutes material sites of networked relationships. However, as an increasing number of mobility practices are making up our everyday life experiences the movement is much mor...... a field of explorations into broader issues of democracy, multiple publics, and new mobile (electronic and material) agoras pointing towards a critical re-interpretation of contemporary politics of space and mobility.......Physical mobility has an important cultural dimension to contemporary life. The movement of objects, signs, and people constitutes material sites of networked relationships. However, as an increasing number of mobility practices are making up our everyday life experiences the movement is much more...... than a travel from point A to point B. The mobile experiences of the contemporary society are practices that are meaningful and normatively embedded. That is to say, mobility is seen as a cultural phenomenon shaping notions of self and other as well as the relationship to sites and places. Furthermore...

  14. NNETS - NEURAL NETWORK ENVIRONMENT ON A TRANSPUTER SYSTEM

    Science.gov (United States)

    Villarreal, J.

    1994-01-01

    The primary purpose of NNETS (Neural Network Environment on a Transputer System) is to provide users a high degree of flexibility in creating and manipulating a wide variety of neural network topologies at processing speeds not found in conventional computing environments. To accomplish this purpose, NNETS supports back propagation and back propagation related algorithms. The back propagation algorithm used is an implementation of Rumelhart's Generalized Delta Rule. NNETS was developed on the INMOS Transputer. NNETS predefines a Back Propagation Network, a Jordan Network, and a Reinforcement Network to assist users in learning and defining their own networks. The program also allows users to configure other neural network paradigms from the NNETS basic architecture. The Jordan network is basically a feed forward network that has the outputs connected to a pseudo input layer. The state of the network is dependent on the inputs from the environment plus the state of the network. The Reinforcement network learns via a scalar feedback signal called reinforcement. The network propagates forward randomly. The environment looks at the outputs of the network to produce a reinforcement signal that is fed back to the network. NNETS was written for the INMOS C compiler D711B version 1.3 or later (MS-DOS version). A small portion of the software was written in the OCCAM language to perform the communications routing between processors. NNETS is configured to operate on a 4 X 10 array of Transputers in sequence with a Transputer based graphics processor controlled by a master IBM PC 286 (or better) Transputer. A RGB monitor is required which must be capable of 512 X 512 resolution. It must be able to receive red, green, and blue signals via BNC connectors. NNETS is meant for experienced Transputer users only. The program is distributed on 5.25 inch 1.2Mb MS-DOS format diskettes. NNETS was developed in 1991. Transputer and OCCAM are registered trademarks of Inmos Corporation. MS

  15. A network-oriented business modeling environment

    Science.gov (United States)

    Bisconti, Cristian; Storelli, Davide; Totaro, Salvatore; Arigliano, Francesco; Savarino, Vincenzo; Vicari, Claudia

    The development of formal models related to the organizational aspects of an enterprise is fundamental when these aspects must be re-engineered and digitalized, especially when the enterprise is involved in the dynamics and value flows of a business network. Business modeling provides an opportunity to synthesize and make business processes, business rules and the structural aspects of an organization explicit, allowing business managers to control their complexity and guide an enterprise through effective decisional and strategic activities. This chapter discusses the main results of the TEKNE project in terms of software components that enable enterprises to configure, store, search and share models of any aspects of their business while leveraging standard and business-oriented technologies and languages to bridge the gap between the world of business people and IT experts and to foster effective business-to-business collaborations.

  16. Artificial neural networks modeling gene-environment interaction

    Directory of Open Access Journals (Sweden)

    Günther Frauke

    2012-05-01

    Full Text Available Abstract Background Gene-environment interactions play an important role in the etiological pathway of complex diseases. An appropriate statistical method for handling a wide variety of complex situations involving interactions between variables is still lacking, especially when continuous variables are involved. The aim of this paper is to explore the ability of neural networks to model different structures of gene-environment interactions. A simulation study is set up to compare neural networks with standard logistic regression models. Eight different structures of gene-environment interactions are investigated. These structures are characterized by penetrance functions that are based on sigmoid functions or on combinations of linear and non-linear effects of a continuous environmental factor and a genetic factor with main effect or with a masking effect only. Results In our simulation study, neural networks are more successful in modeling gene-environment interactions than logistic regression models. This outperfomance is especially pronounced when modeling sigmoid penetrance functions, when distinguishing between linear and nonlinear components, and when modeling masking effects of the genetic factor. Conclusion Our study shows that neural networks are a promising approach for analyzing gene-environment interactions. Especially, if no prior knowledge of the correct nature of the relationship between co-variables and response variable is present, neural networks provide a valuable alternative to regression methods that are limited to the analysis of linearly separable data.

  17. Liner shipping hub network design in a competitive environment

    DEFF Research Database (Denmark)

    Gelareh, Shahin; Nickel, Stefan; Pisinger, David

    2010-01-01

    A mixed integer programming formulation is proposed for hub-and-spoke network design in a competitive environment. It addresses the competition between a newcomer liner service provider and an existing dominating operator, both operating on hub-and-spoke networks. The newcomer company maximizes its...... market share—which depends on the service time and transportation cost—by locating a predefined number of hubs at candidate ports and designing its network. While general-purpose solvers do not solve instances of even small size, an accelerated Lagrangian method combined with a primal heuristic obtains...

  18. Liner Shipping Hub Network Design in a Competitive Environment

    DEFF Research Database (Denmark)

    Gelareh, Shahin; Nickel, Stefan; Pisinger, David

    A new mixed integer programming formulation is proposed for hub-and-spoke network design in a competitive environment. It addresses competition between a newcomer liner service provider and an alliance, both operating on hub-and-spoke networks. The newcomer company maximizes its market share...... — proportional to service time and transportation cost —by locating a predefined number of hubs at candidate ports and designing its network. While general-purpose solvers do not solve instances of even small size, an accelerated lagrangian method coupled with a primal heuristic obtains very good bounds. Our...

  19. Conducting network penetration and espionage in a global environment

    CERN Document Server

    Middleton, Bruce

    2014-01-01

    When it's all said and done, penetration testing remains the most effective way to identify security vulnerabilities in computer networks. Conducting Network Penetration and Espionage in a Global Environment provides detailed guidance on how to perform effective penetration testing of computer networks-using free, open source, and commercially available tools, including Backtrack, Metasploit, Wireshark, Nmap, Netcat, and Nessus. It also considers exploits and other programs using Python, PERL, BASH, PHP, Ruby, and Windows PowerShell.The book taps into Bruce Middleton's decades of experience wi

  20. CALYPSO: a new HF RADAR network to monitor sea surface currents in the Malta-Sicily channel (Mediterranean sea)

    Science.gov (United States)

    Cosoli, S.; Ciraolo, G.; Drago, A.; Capodici, F.; Maltese, A.; Gauci, A.; Galea, A.; Azzopardi, J.; Buscaino, G.; Raffa, F.; Mazzola, S.; Sinatra, R.

    2016-12-01

    Located in one of the main shipping lanes in the Mediterranean Sea, and in a strategic region for oil extraction platforms, the Malta-Sicily channel is exposed to significant oil spill risks. Shipping and extraction activities constitute a major threat for marine areas of relevant ecological value in the area, and impacts of oil spills on the local ecosystems and the economic activities, including tourism and fisheries, can be dramatic. Damages would be even more devastating for the Maltese archipelago, where marine resources represent important economic assets. Additionally, North Africa coastal areas are also under threat, due to their proximity to the Malta-Sicily Channel. Prevention and mitigation measures, together with rapid-response and decision-making in case of emergency situations, are fundamental steps that help accomplishing the tasks of minimizing risks and reducing impacts to the various compartments. Thanks to state-of-art technology for the monitoring of sea-surface currents in real-time under all sea-state conditions, the CALYPSO network of High-Frequency Radars represents an essential and invaluable tool for the specific purpose. HF radars technology provide a unique tool to track surface currents in near-real time, and as such the dispersion of pollutants can be monitored and forecasted and their origin backtracked, for instance through data assimilation into ocean circulation models or through short-term data-driven statistical forecasts of ocean currents. The network is constituted of four SeaSonde systems that work in the 13.5MHz frequency band. The network is operative since August 2012 and has been extensively validated using a variety of independent platforms and devices, including current meter data and drifting buoys. The latter provided clear evidences of the reliability of the collected data as for tracking the drifting objects. Additionally, data have provided a new insight into the oceanographic characteristics of the region

  1. INTELLIGENT MULTI-AGENT PLATFORM WITHIN COLLABORATIVE NETWORKED ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Adina-Georgeta CREŢAN

    2016-06-01

    Full Text Available This paper proposes an agent-based intelligent platform to model and support parallel and concurrent negotiations among organizations acting in the same industrial market. The underlying complexity is to model the dynamic environment where multi-attribute and multi-participant negotiations are racing over a set of heterogeneous resources. The metaphor Interaction Abstract Machines (IAMs is used to model the parallelism and the non-deterministic aspects of the negotiation processes that occur in Collaborative Networked Environment.

  2. AGENT-BASED NEGOTIATION PLATFORM IN COLLABORATIVE NETWORKED ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Adina-Georgeta CREȚAN

    2014-05-01

    Full Text Available This paper proposes an agent-based platform to model and support parallel and concurrent negotiations among organizations acting in the same industrial market. The underlying complexity is to model the dynamic environment where multi-attribute and multi-participant negotiations are racing over a set of heterogeneous resources. The metaphor Interaction Abstract Machines (IAMs is used to model the parallelism and the non-deterministic aspects of the negotiation processes that occur in Collaborative Networked Environment.

  3. Field test of wireless sensor network in the nuclear environment

    Energy Technology Data Exchange (ETDEWEB)

    Li, L., E-mail: lil@aecl.ca [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Wang, Q.; Bari, A. [Univ. of Western Ontario, London, Ontario (Canada); Deng, C.; Chen, D. [Univ. of Electronic Science and Technology of China, Chengdu, Sichuan (China); Jiang, J. [Univ. of Western Ontario, London, Ontario (Canada); Alexander, Q.; Sur, B. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2014-06-15

    Wireless sensor networks (WSNs) are appealing options for the health monitoring of nuclear power plants due to their low cost and flexibility. Before they can be used in highly regulated nuclear environments, their reliability in the nuclear environment and compatibility with existing devices have to be assessed. In situ electromagnetic interference tests, wireless signal propagation tests, and nuclear radiation hardness tests conducted on candidate WSN systems at AECL Chalk River Labs are presented. The results are favourable to WSN in nuclear applications. (author)

  4. Managing Complex Battlespace Environments Using Attack the Network Methodologies

    DEFF Research Database (Denmark)

    Mitchell, Dr. William L.

    This paper examines the last 8 years of development and application of Attack the Network (AtN) intelligence methodologies for creating shared situational understanding of complex battlespace environment and the development of deliberate targeting frameworks. It will present a short history....... Including their possible application on a national security level for managing longer strategic endeavors....

  5. HeNCE: A Heterogeneous Network Computing Environment

    Directory of Open Access Journals (Sweden)

    Adam Beguelin

    1994-01-01

    Full Text Available Network computing seeks to utilize the aggregate resources of many networked computers to solve a single problem. In so doing it is often possible to obtain supercomputer performance from an inexpensive local area network. The drawback is that network computing is complicated and error prone when done by hand, especially if the computers have different operating systems and data formats and are thus heterogeneous. The heterogeneous network computing environment (HeNCE is an integrated graphical environment for creating and running parallel programs over a heterogeneous collection of computers. It is built on a lower level package called parallel virtual machine (PVM. The HeNCE philosophy of parallel programming is to have the programmer graphically specify the parallelism of a computation and to automate, as much as possible, the tasks of writing, compiling, executing, debugging, and tracing the network computation. Key to HeNCE is a graphical language based on directed graphs that describe the parallelism and data dependencies of an application. Nodes in the graphs represent conventional Fortran or C subroutines and the arcs represent data and control flow. This article describes the present state of HeNCE, its capabilities, limitations, and areas of future research.

  6. Dynamic social network analysis using conversational dynamics in social networking and microblogging environments

    Science.gov (United States)

    Stocco, Gabriel; Savell, Robert; Cybenko, George

    2010-04-01

    In many security environments, the textual content of communications may be unavailable. In these instances, it is often desirable to infer the status of the network and its component entities from patterns of communication flow. Conversational dynamics among entities in the network may provide insight into important aspects of the underlying social network such as the formational dynamics of group structures, the active state of these groups, individuals' roles within groups, and the likelihood of individual participation in conversations. To gain insight into the use of conversational dynamics to facilitate Dynamic Social Network Analysis, we explore the use of interevent timings to associate entities in the Twitter social networking and micro-blogging environment. Specifically, we use message timings to establish inter-nodal relationships among participants. In addition, we demonstrate a new visualization technique for tracking levels of coordination or synchronization within the community via measures of socio-temporal coherence of the participants.

  7. Error analysis for RADAR neighbor matching localization in linear logarithmic strength varying Wi-Fi environment

    National Research Council Canada - National Science Library

    Zhou, Mu; Tian, Zengshan; Xu, Kunjie; Yu, Xiang; Wu, Haibo

    2014-01-01

    ...) in logarithmic received signal strength (RSS) varying Wi-Fi environment. To the best of our knowledge, little comprehensive analysis work has appeared on the error performance of neighbor matching localization with respect to the deployment of RPs...

  8. Error Analysis for RADAR Neighbor Matching Localization in Linear Logarithmic Strength Varying Wi-Fi Environment

    National Research Council Canada - National Science Library

    Zhou, Mu; Tian, Zengshan; Xu, Kunjie; Yu, Xiang; Wu, Haibo

    2014-01-01

    ...) in logarithmic received signal strength (RSS) varying Wi-Fi environment. To the best of our knowledge, little comprehensive analysis work has appeared on the error performance of neighbor matching localization with respect to the deployment of RPs...

  9. Integrated Environment for Ubiquitous Healthcare and Mobile IPv6 Networks

    Science.gov (United States)

    Cagalaban, Giovanni; Kim, Seoksoo

    The development of Internet technologies based on the IPv6 protocol will allow real-time monitoring of people with health deficiencies and improve the independence of elderly people. This paper proposed a ubiquitous healthcare system for the personalized healthcare services with the support of mobile IPv6 networks. Specifically, this paper discusses the integration of ubiquitous healthcare and wireless networks and its functional requirements. This allow an integrated environment where heterogeneous devices such a mobile devices and body sensors can continuously monitor patient status and communicate remotely with healthcare servers, physicians, and family members to effectively deliver healthcare services.

  10. Department of the Navy Naval Networking Environment (NNE)-2016. Strategic Definition, Scope and Strategy Paper, Version 1.1

    Science.gov (United States)

    2008-05-13

    optimized network environment with many nodes not capable of operating in a globally networked environment . In today’s changing environment of network... environment to enhance the Department’s organizational flexibility and global awareness. This environment must facilitate the rapid information sharing...Department of the Naval Networking Environment (NNE)~2016 Strategic Definition, Scope and Strategy Department of the Navy Naval Networking

  11. A Cognitive Approach to Network Monitoring in Heterogeneous Environments

    DEFF Research Database (Denmark)

    Mihovska, Albena D.

    2007-01-01

    of information (QoI). QoI means QoS while all the requirements for dependability, security, privacy and trust are satisfied at the highest possible level. This work proposes and describes an approach to network monitoring in a heterogeneous communication environment based on use of cognitive techniques...... for efficient resource allocation, provisioning of network resources or for detection of security violations into the traditional network monitoring approach. The paper describes the cognitive monitoring architecture, the required physical and logical entities, and their functionalities. Further, the paper......Abstract— Introducing intelligence by means of cognition for managing, protecting, processing, and delivering of information in mobile communication systems is the way towards ubiquitous, converged and secure communications. In this context, this paper introduces the concept of quality...

  12. Optimal Detection in the K-Distributed Clutter Environment -- Non-Coherent Radar Processing

    Science.gov (United States)

    2012-12-01

    To find the MLE of , we must minimise with respect to , where cM 2 )( 2J 2 N n n H n nJ 1 2 2 22 ln)( xE (22) Differentiating leads to a...uncorrelated, its best estimate is its global mean . The optimal and near-optimal 3 Matlab defines...CONTROL DATA 1. PRIVACY MARKING/CAVEAT (OF DOCUMENT) 2. TITLE Optimal Detection in the K-Distributed Clutter Environment -- Non- Coherent

  13. Stochastic Simulation of Biomolecular Networks in Dynamic Environments.

    Science.gov (United States)

    Voliotis, Margaritis; Thomas, Philipp; Grima, Ramon; Bowsher, Clive G

    2016-06-01

    Simulation of biomolecular networks is now indispensable for studying biological systems, from small reaction networks to large ensembles of cells. Here we present a novel approach for stochastic simulation of networks embedded in the dynamic environment of the cell and its surroundings. We thus sample trajectories of the stochastic process described by the chemical master equation with time-varying propensities. A comparative analysis shows that existing approaches can either fail dramatically, or else can impose impractical computational burdens due to numerical integration of reaction propensities, especially when cell ensembles are studied. Here we introduce the Extrande method which, given a simulated time course of dynamic network inputs, provides a conditionally exact and several orders-of-magnitude faster simulation solution. The new approach makes it feasible to demonstrate-using decision-making by a large population of quorum sensing bacteria-that robustness to fluctuations from upstream signaling places strong constraints on the design of networks determining cell fate. Our approach has the potential to significantly advance both understanding of molecular systems biology and design of synthetic circuits.

  14. Stochastic Simulation of Biomolecular Networks in Dynamic Environments.

    Directory of Open Access Journals (Sweden)

    Margaritis Voliotis

    2016-06-01

    Full Text Available Simulation of biomolecular networks is now indispensable for studying biological systems, from small reaction networks to large ensembles of cells. Here we present a novel approach for stochastic simulation of networks embedded in the dynamic environment of the cell and its surroundings. We thus sample trajectories of the stochastic process described by the chemical master equation with time-varying propensities. A comparative analysis shows that existing approaches can either fail dramatically, or else can impose impractical computational burdens due to numerical integration of reaction propensities, especially when cell ensembles are studied. Here we introduce the Extrande method which, given a simulated time course of dynamic network inputs, provides a conditionally exact and several orders-of-magnitude faster simulation solution. The new approach makes it feasible to demonstrate-using decision-making by a large population of quorum sensing bacteria-that robustness to fluctuations from upstream signaling places strong constraints on the design of networks determining cell fate. Our approach has the potential to significantly advance both understanding of molecular systems biology and design of synthetic circuits.

  15. Efficient extraction of drainage networks from massive, radar-based elevation models with least cost path search

    Directory of Open Access Journals (Sweden)

    M. Metz

    2011-02-01

    Full Text Available The availability of both global and regional elevation datasets acquired by modern remote sensing technologies provides an opportunity to significantly improve the accuracy of stream mapping, especially in remote, hard to reach regions. Stream extraction from digital elevation models (DEMs is based on computation of flow accumulation, a summary parameter that poses performance and accuracy challenges when applied to large, noisy DEMs generated by remote sensing technologies. Robust handling of DEM depressions is essential for reliable extraction of connected drainage networks from this type of data. The least-cost flow routing method implemented in GRASS GIS as the module r.watershed was redesigned to significantly improve its speed, functionality, and memory requirements and make it an efficient tool for stream mapping and watershed analysis from large DEMs. To evaluate its handling of large depressions, typical for remote sensing derived DEMs, three different methods were compared: traditional sink filling, impact reduction approach, and least-cost path search. The comparison was performed using the Shuttle Radar Topographic Mission (SRTM and Interferometric Synthetic Aperture Radar for Elevation (IFSARE datasets covering central Panama at 90 m and 10 m resolutions, respectively. The accuracy assessment was based on ground control points acquired by GPS and reference points digitized from Landsat imagery along segments of selected Panamanian rivers. The results demonstrate that the new implementation of the least-cost path method is significantly faster than the original version, can cope with massive datasets, and provides the most accurate results in terms of stream locations validated against reference points.

  16. An environment-dependent transcriptional network specifies human microglia identity.

    Science.gov (United States)

    Gosselin, David; Skola, Dylan; Coufal, Nicole G; Holtman, Inge R; Schlachetzki, Johannes C M; Sajti, Eniko; Jaeger, Baptiste N; O'Connor, Carolyn; Fitzpatrick, Conor; Pasillas, Martina P; Pena, Monique; Adair, Amy; Gonda, David D; Levy, Michael L; Ransohoff, Richard M; Gage, Fred H; Glass, Christopher K

    2017-06-23

    Microglia play essential roles in central nervous system (CNS) homeostasis and influence diverse aspects of neuronal function. However, the transcriptional mechanisms that specify human microglia phenotypes are largely unknown. We examined the transcriptomes and epigenetic landscapes of human microglia isolated from surgically resected brain tissue ex vivo and after transition to an in vitro environment. Transfer to a tissue culture environment resulted in rapid and extensive down-regulation of microglia-specific genes that were induced in primitive mouse macrophages after migration into the fetal brain. Substantial subsets of these genes exhibited altered expression in neurodegenerative and behavioral diseases and were associated with noncoding risk variants. These findings reveal an environment-dependent transcriptional network specifying microglia-specific programs of gene expression and facilitate efforts to understand the roles of microglia in human brain diseases. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  17. MUPBED - interworking challenges in a multi-domain and multi-technology network environment

    DEFF Research Database (Denmark)

    Foisel, Hans-Martin; Spaeth, Jan; Cavazzoni, Carlo

    2007-01-01

    Todays data transport networks are evolving continuously towards customer oriented and application aware networks. This evolution happens in Europe in a highly diverse network environment, covering multiple network domains, layers, technologies, control and management approaches. In this paper......, the issues, challenges and the solutions developed in the IST project MUPBED (,,Multi-Partner European Test Beds for Research Networking; www.ist-mupbed.eu) for seamless interworking in a typical European heterogeneous network environment are described, addressing horizontal, interdomain, and vertical, inter...

  18. Partially blind instantly decodable network codes for lossy feedback environment

    KAUST Repository

    Sorour, Sameh

    2014-09-01

    In this paper, we study the multicast completion and decoding delay minimization problems for instantly decodable network coding (IDNC) in the case of lossy feedback. When feedback loss events occur, the sender falls into uncertainties about packet reception at the different receivers, which forces it to perform partially blind selections of packet combinations in subsequent transmissions. To determine efficient selection policies that reduce the completion and decoding delays of IDNC in such an environment, we first extend the perfect feedback formulation in our previous works to the lossy feedback environment, by incorporating the uncertainties resulting from unheard feedback events in these formulations. For the completion delay problem, we use this formulation to identify the maximum likelihood state of the network in events of unheard feedback and employ it to design a partially blind graph update extension to the multicast IDNC algorithm in our earlier work. For the decoding delay problem, we derive an expression for the expected decoding delay increment for any arbitrary transmission. This expression is then used to find the optimal policy that reduces the decoding delay in such lossy feedback environment. Results show that our proposed solutions both outperform previously proposed approaches and achieve tolerable degradation even at relatively high feedback loss rates.

  19. Flood monitoring in a semi-arid environment using spatially high resolution radar and optical data.

    Science.gov (United States)

    Seiler, Ralf; Schmidt, Jana; Diallo, Ousmane; Csaplovics, Elmar

    2009-05-01

    The geographic term "Niger Inland Delta" stands for a vast plain of approximately 40,000 km(2), which is situated in the western Sahel (Republic of Mali). The Inland Delta is affected by yearly inundation through the variable water levels of the Niger-Bani river system. Due to a good availability of (surface) water, the ecosystem at the Niger Inland Delta serves as resting place stop-over for many migrating birds and other wildlife species as well as economic base for farmers and pastoral people. To foster the sustainable usage of its natural resources and to protect this natural heritage, the entire Niger Inland Delta became RAMSAR site in 2004. This paper aims to test to which extent texture analysis can improve the quality of flood monitoring in a semi-arid environment using spatially high resolution ASAR imaging mode data. We found the Gray Level Dependence Method (GLDM) was most suitable proceeding for our data. Several statistical parameters were calculated via co-occurrence matrices and were used to classify the images in different gradation of soil moisture classes. In a second step we used additional information from spatially high resolution optical data (ASTER) to improve the separability of open water areas from moisture/vegetated areas.

  20. Supporting tactical intelligence using collaborative environments and social networking

    Science.gov (United States)

    Wollocko, Arthur B.; Farry, Michael P.; Stark, Robert F.

    2013-05-01

    Modern military environments place an increased emphasis on the collection and analysis of intelligence at the tactical level. The deployment of analytical tools at the tactical level helps support the Warfighter's need for rapid collection, analysis, and dissemination of intelligence. However, given the lack of experience and staffing at the tactical level, most of the available intelligence is not exploited. Tactical environments are staffed by a new generation of intelligence analysts who are well-versed in modern collaboration environments and social networking. An opportunity exists to enhance tactical intelligence analysis by exploiting these personnel strengths, but is dependent on appropriately designed information sharing technologies. Existing social information sharing technologies enable users to publish information quickly, but do not unite or organize information in a manner that effectively supports intelligence analysis. In this paper, we present an alternative approach to structuring and supporting tactical intelligence analysis that combines the benefits of existing concepts, and provide detail on a prototype system embodying that approach. Since this approach employs familiar collaboration support concepts from social media, it enables new-generation analysts to identify the decision-relevant data scattered among databases and the mental models of other personnel, increasing the timeliness of collaborative analysis. Also, the approach enables analysts to collaborate visually to associate heterogeneous and uncertain data within the intelligence analysis process, increasing the robustness of collaborative analyses. Utilizing this familiar dynamic collaboration environment, we hope to achieve a significant reduction of time and skill required to glean actionable intelligence in these challenging operational environments.

  1. Use of Dual-Polarization Radar Variables to Assess Low-Level Wind Shear in Severe Thunderstorm Near-storm Environments in the Tennessee Valley

    Science.gov (United States)

    Crowe, Christina C.; Schultz, Christopher J.; Kumjian, Matthew; Carey, Lawerence D.; Petersen, Walter A.

    2011-01-01

    The upgrade of the National Weather Service (NWS) network of S ]band dual-polarization radars is currently underway, and the incorporation of polarimetric information into the real ]time forecasting process will enhance the forecaster fs ability to assess thunderstorms and their near ]storm environments. Recent research has suggested that the combination of polarimetric variables differential reflectivity (ZDR) and specific differential phase (KDP) can be useful in the assessment of low level wind shear within a thunderstorm. In an environment with strong low ]level veering of the wind, ZDR values will be largest along the right inflow edge of the thunderstorm near a large gradient in horizontal reflectivity (indicative of large raindrops falling with a relative lack of smaller drops), and take the shape of an arc. Meanwhile, KDP values, which are proportional to liquid water content and indicative of a large number of smaller drops, are maximized deeper into the forward flank precipitation shield than the ZDR arc as the smaller drops are being advected further from the updraft core by the low level winds than the larger raindrops. Using findings from previous work, three severe weather events that occurred in North Alabama were examined in order to assess the utility of these signatures in determining the potential for tornadic activity. The first case is from October 26, 2010, where a large number of storms indicated tornadic potential from a standard reflectivity and velocity analysis but very few storms actually produced tornadoes. The second event is from February 28, 2011, where tornadic storms were present early on in the event, but as the day progressed, the tornado threat transitioned to a high wind threat. The third case is from April 27, 2011, where multiple rounds of tornadic storms ransacked the Tennessee Valley. This event provides a dataset including multiple modes of tornadic development, including QLCS and supercell structures. The overarching goal

  2. "Development Radar": The Co-Configuration of a Tool in a Learning Network

    Science.gov (United States)

    Toiviainen, Hanna; Kerosuo, Hannele; Syrjala, Tuula

    2009-01-01

    Purpose: The paper aims to argue that new tools are needed for operating, developing and learning in work-life networks where academic and practice knowledge are intertwined in multiple levels of and in boundary-crossing across activities. At best, tools for learning are designed in a process of co-configuration, as the analysis of one tool,…

  3. Synthetic aperture radar ship discrimination, generation and latent variable extraction using information maximizing generative adversarial networks

    CSIR Research Space (South Africa)

    Schwegmann, Colin P

    2017-07-01

    Full Text Available Maximizing Generative Adversarial Network extend this idea by extracting untangled latent variables as part of the discrimination process which help to classify the data in terms of categories/classes and properties such as ship rotation. Despite the limited...

  4. A Critical Evaluation of Ground-Penetrating Radar Methodology on the Kalavasos and Maroni Built Environments (KAMBE) Project, Cyprus (Invited)

    Science.gov (United States)

    Leon, J.; Urban, T.; Gerard-Little, P.; Kearns, C.; Manning, S. W.; Fisher, K.; Rogers, M.

    2013-12-01

    at these settlements. Having just completed this first phase of the project, we report on the results of large-scale geophysical survey, including the identification of at least two previously unknown building complexes (one at each site). Here we focus particularly on ground-penetrating radar (GPR) data and survey methodology, in an effort to critically examine the range of approaches applied throughout the project (e.g. various antennae frequencies, data-collection densities, soil moisture/seasonality of survey, and post-collection data processing [2]), and to identify the most effective parameters for archaeological geophysical survey in the region. This paper also advocates for the role of geophysical survey within a multi-component archaeological project, not simply as a prospection tool but as an archaeological data collection method in its own right. 1]Fisher, K. D., J. Leon, S. Manning, M. Rogers, and D. Sewell. In Press. 2011-2012. 'The Kalavasos and Maroni Built Environments Project: Introduction and preliminary report on the 2008 and 2010 seasons. Report of the Department of Antiquities, Cyprus. 2] e.g. Rogers, M., J. F. Leon, K. D. Fisher, S. W. Manning and D. Sewell. 2012. 'Comparing similar ground-penetrating radar surveys under different soil moisture conditions at Kalavasos-Ayios Dhimitrios, Cyprus.' Archaeological Prospection 19 (4): 297-305.

  5. Scholarly information discovery in the networked academic learning environment

    CERN Document Server

    Li, LiLi

    2014-01-01

    In the dynamic and interactive academic learning environment, students are required to have qualified information literacy competencies while critically reviewing print and electronic information. However, many undergraduates encounter difficulties in searching peer-reviewed information resources. Scholarly Information Discovery in the Networked Academic Learning Environment is a practical guide for students determined to improve their academic performance and career development in the digital age. Also written with academic instructors and librarians in mind who need to show their students how to access and search academic information resources and services, the book serves as a reference to promote information literacy instructions. This title consists of four parts, with chapters on the search for online and printed information via current academic information resources and services: part one examines understanding information and information literacy; part two looks at academic information delivery in the...

  6. Social Networks as Learning Environments for Higher Education

    Directory of Open Access Journals (Sweden)

    J.A.Cortés

    2014-09-01

    Full Text Available Learning is considered as a social activity, a student does not learn only of the teacher and the textbook or only in the classroom, learn also from many other agents related to the media, peers and society in general. And since the explosion of the Internet, the information is within the reach of everyone, is there where the main area of opportunity in new technologies applied to education, as well as taking advantage of recent socialization trends that can be leveraged to improve not only informing of their daily practices, but rather as a tool that explore different branches of education research. One can foresee the future of higher education as a social learning environment, open and collaborative, where people construct knowledge in interaction with others, in a comprehensive manner. The mobility and ubiquity that provide mobile devices enable the connection from anywhere and at any time. In modern educational environments can be expected to facilitate mobile devices in the classroom expansion in digital environments, so that students and teachers can build the teaching-learning process collectively, this partial derivative results in the development of draft research approved by the CONADI in “Universidad Cooperativa de Colombia”, "Social Networks: A teaching strategy in learning environments in higher education."

  7. Feasibility of Spectrum Sharing Between Airborne Weather Radar and Wireless Local Area Networks

    OpenAIRE

    Zarookian, Ruffy

    2007-01-01

    Emerging technologies such as wireless local area networks and cellular telephones have dramatically increased the use of wireless communications services within the last 10 years. The shortage of available spectrum exists due to increasing demand for wireless services and current spectrum allocation regulations. To alleviate this shortage, Research aims to improve spectral efficiency and to allow spectrum sharing between separatelymanaged and non-coordinating communications systems. T...

  8. SNP by SNP by environment interaction network of alcoholism.

    Science.gov (United States)

    Zollanvari, Amin; Alterovitz, Gil

    2017-03-14

    Alcoholism has a strong genetic component. Twin studies have demonstrated the heritability of a large proportion of phenotypic variance of alcoholism ranging from 50-80%. The search for genetic variants associated with this complex behavior has epitomized sequence-based studies for nearly a decade. The limited success of genome-wide association studies (GWAS), possibly precipitated by the polygenic nature of complex traits and behaviors, however, has demonstrated the need for novel, multivariate models capable of quantitatively capturing interactions between a host of genetic variants and their association with non-genetic factors. In this regard, capturing the network of SNP by SNP or SNP by environment interactions has recently gained much interest. Here, we assessed 3,776 individuals to construct a network capable of detecting and quantifying the interactions within and between plausible genetic and environmental factors of alcoholism. In this regard, we propose the use of first-order dependence tree of maximum weight as a potential statistical learning technique to delineate the pattern of dependencies underpinning such a complex trait. Using a predictive based analysis, we further rank the genes, demographic factors, biological pathways, and the interactions represented by our SNP [Formula: see text]SNP[Formula: see text]E network. The proposed framework is quite general and can be potentially applied to the study of other complex traits.

  9. 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.

  10. Emergence of microbial networks as response to hostile environments.

    Science.gov (United States)

    Madeo, Dario; Comolli, Luis R; Mocenni, Chiara

    2014-01-01

    The majority of microorganisms live in complex communities under varying conditions. One pivotal question in evolutionary biology is the emergence of cooperative traits and their sustainment in altered environments or in the presence of free-riders. Co-occurrence patterns in the spatial distribution of biofilms can help define species' identities, and systems biology tools are revealing networks of interacting microorganisms. However, networks of inter-dependencies involving micro-organisms in the planktonic phase may be just as important, with the added complexity that they are not bounded in space. An integrated approach linking imaging, "Omics" and modeling has the potential to enable new hypothesis and working models. In order to understand how cooperation can emerge and be maintained without abilities like memory or recognition we use evolutionary game theory as the natural framework to model cell-cell interactions arising from evolutive decisions. We consider a finite population distributed in a spatial domain (biofilm), and divided into two interacting classes with different traits. This interaction can be weighted by distance, and produces physical connections between two elements allowing them to exchange finite amounts of energy and matter. Available strategies to each individual of one class in the population are the propensities or "willingness" to connect any individual of the other class. Following evolutionary game theory, we propose a mathematical model which explains the patterns of connections which emerge when individuals are able to find connection strategies that asymptotically optimize their fitness. The process explains the formation of a network for efficiently exchanging energy and matter among individuals and thus ensuring their survival in hostile environments.

  11. Emergence of microbial networks as response to hostile environments

    Directory of Open Access Journals (Sweden)

    Dario eMadeo

    2014-08-01

    Full Text Available The majority of microorganisms live in complex communities under varying conditions. One pivotal question in evolutionary biology is the emergence of cooperative traits and their sustainment in altered environments or in the presence of free-riders. Co-occurrence patterns in the spatial distribution of biofilms can help define species' identities, and systems biology tools are revealing networks of interacting microorganisms. However, networks of inter-dependencies involving micro-organisms in the planktonic phase may be just as important, with the added complexity that they are not bounded in space. An integrated approach linking imaging, ``Omics'' and modeling has the potential to enable new hypothesis and working models. In order to understand how cooperation can emerge and be maintained without abilities like memory or recognition we use evolutionary game theory as the natural framework to model cell-cell interactions arising from evolutive decisions. We consider a finite population distributed in a spatial domain (biofilm, and divided into two interacting classes with different traits. This interaction can be weighted by distance, and produces physical connections between two elements allowing them to exchange finite amounts of energy and matter. Available strategies to each individual of one class in the population are the propensities or ``willingness'' to connect any individual of the other class. Following evolutionary game theory, we propose a mathematical model which explains the patterns of connections which emerge when individuals are able to find connection strategies that asymptotically optimize their fitness. The process explains the formation of a network for efficiently exchanging energy and matter among individuals and thus ensuring their survival in hostile environments.

  12. Quantum radar

    CERN Document Server

    Lanzagorta, Marco

    2011-01-01

    This book offers a concise review of quantum radar theory. Our approach is pedagogical, making emphasis on the physics behind the operation of a hypothetical quantum radar. We concentrate our discussion on the two major models proposed to date: interferometric quantum radar and quantum illumination. In addition, this book offers some new results, including an analytical study of quantum interferometry in the X-band radar region with a variety of atmospheric conditions, a derivation of a quantum radar equation, and a discussion of quantum radar jamming.This book assumes the reader is familiar w

  13. Cloud-Centric and Logically Isolated Virtual Network Environment Based on Software-Defined Wide Area Network

    Directory of Open Access Journals (Sweden)

    Dongkyun Kim

    2017-12-01

    Full Text Available Recent development of distributed cloud environments requires advanced network infrastructure in order to facilitate network automation, virtualization, high performance data transfer, and secured access of end-to-end resources across regional boundaries. In order to meet these innovative cloud networking requirements, software-defined wide area network (SD-WAN is primarily demanded to converge distributed cloud resources (e.g., virtual machines (VMs in a programmable and intelligent manner over distant networks. Therefore, this paper proposes a logically isolated networking scheme designed to integrate distributed cloud resources to dynamic and on-demand virtual networking over SD-WAN. The performance evaluation and experimental results of the proposed scheme indicate that virtual network convergence time is minimized in two different network models such as: (1 an operating OpenFlow-oriented SD-WAN infrastructure (KREONET-S which is deployed on the advanced national research network in Korea, and (2 Mininet-based experimental and emulated networks.

  14. The Worldviews Network: Transformative Global Change Education in Immersive Environments

    Science.gov (United States)

    Hamilton, H.; Yu, K. C.; Gardiner, N.; McConville, D.; Connolly, R.; "Irving, Lindsay", L. S.

    2011-12-01

    Our modern age is defined by an astounding capacity to generate scientific information. From DNA to dark matter, human ingenuity and technologies create an endless stream of data about ourselves and the world of which we are a part. Yet we largely founder in transforming information into understanding, and understanding into rational action for our society as a whole. Earth and biodiversity scientists are especially frustrated by this impasse because the data they gather often point to a clash between Earth's capacity to sustain life and the decisions that humans make to garner the planet's resources. Immersive virtual environments offer an underexplored link in the translation of scientific data into public understanding, dialogue, and action. The Worldviews Network is a collaboration of scientists, artists, and educators focused on developing best practices for the use of immersive environments for science-based ecological literacy education. A central tenet of the Worldviews Network is that there are multiple ways to know and experience the world, so we are developing scientifically accurate, geographically relevant, and culturally appropriate programming to promote ecological literacy within informal science education programs across the United States. The goal of Worldviews Network is to offer transformative learning experiences, in which participants are guided on a process integrating immersive visual explorations, critical reflection and dialogue, and design-oriented approaches to action - or more simply, seeing, knowing, and doing. Our methods center on live presentations, interactive scientific visualizations, and sustainability dialogues hosted at informal science institutions. Our approach uses datasets from the life, Earth, and space sciences to illuminate the complex conditions that support life on earth and the ways in which ecological systems interact. We are leveraging scientific data from federal agencies, non-governmental organizations, and our

  15. Radar Chart

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Radar Chart collection is an archived product of summarized radar data. The geographic coverage is the 48 contiguous states of the United States. These hourly...

  16. Representing the environment 3.0. Maps, models, networks.

    Directory of Open Access Journals (Sweden)

    Letizia Bollini

    2014-05-01

    Full Text Available Web 3.0 is changing the world we live and perceive the environment anthropomorphized, making a stratifation of levels of experience and mediated by the devices. If the urban landscape is designed, shaped and planned space, there is a social landscape that overwrite the territory of values, representations shared images, narratives of personal and collective history. Mobile technology introduces an additional parameter, a kind of non-place, which allows the coexistence of the here and elsewhere in an sort of digital landscape. The maps, mental models, the system of social networks become, then, the way to present, represented and represent themselves in a kind of ideal coring of the co-presence of levels of physical, cognitive and collective space.

  17. Hands-On Learning Modules for Interdisciplinary Environments: An Example with a Focus on Weather Radar Applications

    Science.gov (United States)

    Chilson, P. B.; Yeary, M. B.

    2012-01-01

    Learning modules provide an effective means of encouraging cognition and active learning. This paper discusses several such modules that have been developed within a course on weather radar applications intended for students from Electrical Engineering and Meteorology. The modules were designed both to promote interdisciplinary exchange between…

  18. Performance Analysis of CDMA Wireless Sensor Networks in Shadowed Environment

    Directory of Open Access Journals (Sweden)

    U. DATTA

    2010-07-01

    Full Text Available This paper evaluates the performance of a CDMA based wireless sensor networks (WSN with layered architecture in terms of QoS like outage probability, bit error rate (BER, throughput, and delay, considering correlation amongst interferers in shadowed environment. Energy consumption for successful delivery of information is also evaluated at different channel conditions. Two kinds of interference namely multiple access interference (MAI and node interference (NI are considered and an infinite ARQ is assumed at link layer between a sending node and sink till successful transmission of packetized data. An appropriate analytical model of interference considering correlation amongst interferers, power control error and shadowing is developed for evaluating bit error rate (BER, packet error rate (PER, average number of retransmission for successful delivery of information, throughput, and delay in a single hop communication. A simple energy model is used for evaluating the consumption of energy for successful delivery of information between source and sink. We also evaluate the sink capacity of wireless CDMA sensor networks considering a threshold BER. Sink capacity is defined as the maximum number of sensor nodes transmitting concurrently to the sink and located within one hop layer. The impact of NI on the sink capacity is also indicated. The effects of node density, correlation amongst interferers and power control error (pce on performance of WSN are investigated. Analytical results are supported by simulation results.

  19. Developing a virtualised testbed environment in preparation for testing of network based attacks

    CSIR Research Space (South Africa)

    Van Heerden, RP

    2013-11-01

    Full Text Available the authors to reset the simulation environment before each test and mitigated against the damage that an attack potentially inflicts on the test network. Without simulated network traffic, the virtualised network was too sterile. This resulted in any network...

  20. Use of the SAR (Synthetic Aperture Radar) P band for detection of the Moche and Lambayeque canal networks in the Apurlec region, Perù

    Science.gov (United States)

    Ilaria Pannaccione Apa, Maria; Santovito, Maria Rosaria; Pica, Giulia; Catapano, Ilaria; Fornaro, Gianfranco; Lanari, Riccardo; Soldovieri, Francesco; Wester La Torre, Carlos; Fernandez Manayalle, Marco Antonio; Longo, Francesco; Facchinetti, Claudia; Formaro, Roberto

    2016-04-01

    , glaciers investigation, biomass monitoring, detection of buried targets. Its extension to non-civil application concerns sub-surface target detection and foliage penetration (FOPEN). In order to achieve the flexibility to face all the above mentioned fields of application, the CORISTA system has been designed as a multi-mode and multi-frequency radar. Multimode stands for the functionality of the system both as Sounder and Imager. In addition, P-band radar is a multi-frequency instrument, since it is designed to work in three different frequency bands, as mentioned above: lower frequency band is used in sounder operative mode, higher frequency in imager operative mode. In the Imager operative mode, low resolution and high resolution capabilities are implemented. The data collected by the radar system have been processed using a model-based microwave tomographic approach, recently developed by IREA-CNR, with the aim to enhance the interpretability of the raw-data radar images. Currently, the non-invasive SAR P band application is under evaluation for testing in the Northern Coast of Perù, in collaboration with the Museo Arqueológico Nacional Brüning. The project will aim to recognize the subsurface ancient Moche (100-700 d.C.) and Lambayeque (700-1375 d.C.) canal networks, whose water supply comes from the Canal Taymi, started to be dug by the Mochicas, still in use by local communities.

  1. Neural network architecture for cognitive navigation in dynamic environments.

    Science.gov (United States)

    Villacorta-Atienza, José Antonio; Makarov, Valeri A

    2013-12-01

    Navigation in time-evolving environments with moving targets and obstacles requires cognitive abilities widely demonstrated by even simplest animals. However, it is a long-standing challenging problem for artificial agents. Cognitive autonomous robots coping with this problem must solve two essential tasks: 1) understand the environment in terms of what may happen and how I can deal with this and 2) learn successful experiences for their further use in an automatic subconscious way. The recently introduced concept of compact internal representation (CIR) provides the ground for both the tasks. CIR is a specific cognitive map that compacts time-evolving situations into static structures containing information necessary for navigation. It belongs to the class of global approaches, i.e., it finds trajectories to a target when they exist but also detects situations when no solution can be found. Here we extend the concept of situations with mobile targets. Then using CIR as a core, we propose a closed-loop neural network architecture consisting of conscious and subconscious pathways for efficient decision-making. The conscious pathway provides solutions to novel situations if the default subconscious pathway fails to guide the agent to a target. Employing experiments with roving robots and numerical simulations, we show that the proposed architecture provides the robot with cognitive abilities and enables reliable and flexible navigation in realistic time-evolving environments. We prove that the subconscious pathway is robust against uncertainty in the sensory information. Thus if a novel situation is similar but not identical to the previous experience (because of, e.g., noisy perception) then the subconscious pathway is able to provide an effective solution.

  2. Efficient Ways to Learn Weather Radar Polarimetry

    Science.gov (United States)

    Cao, Qing; Yeary, M. B.; Zhang, Guifu

    2012-01-01

    The U.S. weather radar network is currently being upgraded with dual-polarization capability. Weather radar polarimetry is an interdisciplinary area of engineering and meteorology. This paper presents efficient ways to learn weather radar polarimetry through several basic and practical topics. These topics include: 1) hydrometeor scattering model…

  3. Jet stream related observations by MST radars

    Science.gov (United States)

    Gage, K. S.

    1983-01-01

    An overview of the jet stream and its observation by MST radar is presented. The climatology and synoptic and mesoscale structure of jet streams is briefly reviewed. MST radar observations of jet stream winds, and associated waves and turbulence are then considered. The possibility of using a network of ST radars to track jet stream winds in near real time is explored.

  4. Radar Fundamentals, Presentation

    OpenAIRE

    Jenn, David

    2008-01-01

    Topics include: introduction, radar functions, antennas basics, radar range equation, system parameters, electromagnetic waves, scattering mechanisms, radar cross section and stealth, and sample radar systems.

  5. Towards the azimuthal characteristics of ionospheric and seismic effects of "Chelyabinsk" meteorite fall according to the data from coherent radar, GPS and seismic networks

    CERN Document Server

    Berngardt, O I; Kutelev, K A; Zherebtsov, G A; Dobrynina, A A; Shestakov, N V; Zagretdinov, R V; Bakhtiyarov, V F; Kusonsky, O A

    2015-01-01

    We present the results of a study of the azimuthal characteristics of ionospheric and seismic effects of the meteorite 'Chelyabinsk', based on the data from the network of GPS receivers, coherent decameter radar EKB SuperDARN and network of seismic stations. It is shown, that 6-14 minutes after the bolide explosion, GPS network observed the cone-shaped wavefront of TIDs that is interpreted as a ballistic acoustic wave. The typical TIDs propagation velocity were observed 661+/-256m/s, which corresponds to the expected acoustic wave speed for 240km height. 14 minutes after the bolide explosion, at distances of 200km we observed the emergence and propagation of a TID with spherical wavefront, that is interpreted as gravitational mode of internal acoustic waves. The propagation velocity of this TID was 337+/-89m/s which corresponds to the propagation velocity of these waves in similar situations. At EKB SuperDARN radar, we observed TIDs in the sector of azimuthal angles close to the perpendicular to the meteorite...

  6. Kinematic and Thermodynamic Study of a Shallow Hailstorm Sampled by the McGill Bistatic Multiple-Doppler Radar Network.

    Science.gov (United States)

    Protat, Alain; Zawadzki, Isztar; Caya, Alain

    2001-05-01

    In this paper, the authors examine the kinematic and thermodynamic characteristics of a shallow hailstorm sampled by the McGill bistatic multiple-Doppler radar network on 26 May 1997. This storm consists of two main shallow convective cells (depth less than 5 km) aligned along a SW-NE convective line propagating to the southeast. The authors also analyze the interactions between the two cells during the life cycle of the convective line. In particular it is shown that dynamic interactions play a major role in the intensification of the second cell. This storm is found to evolve in a manner that shares some characteristics with both multicell and supercell storms. A rotating updraft associated with a mesocyclone develops in the mature stage of the storm, which is characteristic of a supercell. However, the lack of a `vault' structure on the precipitation field, the relatively fast evolution of the cells, and other characteristics detailed henceforth seem to indicate that this storm only shares a few of the typical characteristics of supercells. Some morphological and thermodynamic similarities are found between this storm and recent numerical simulations of shallow supercell storms. While the first cell starts dissipating, a cold downward rear inflow is developing, which resembles the `rear-flank' downdraft documented in several numerical and observational studies of tornadic storms. This downdraft acts to intensify the updraft associated with the second cell and produces a precipitation overhang within which hail eventually forms. When this pocket of hail falls to the ground a bit later, it accelerates the low-level rear inflow that progressively cuts off the inflow ahead of the storm, leading to the progressive dissipation of the second cell.The physical processes involved in the evolution of rotation at low levels to midlevels within this storm are evaluated using the vorticity equation. It is shown that the time tendency of the positive and negative vertical

  7. IMPLEMENTATION OF WIRED AND WIRELESS NETWORK IN ACADEMIC ENVIRONMENT

    OpenAIRE

    Raman Bhanot*

    2017-01-01

    Formerly, wired network has verified its capabilities but in this day and age wireless communication has emerged as a robust and most intellectual communication technique. Both the types have its own merits and demerits based on its network characteristics. Wired and wireless networking has different hardware necessities, ranges, mobility, reliability and benefits.The aim of the paper is to provide a simulated outlook of Wireless and Wired Network covering whole campus. This simulation has be...

  8. Planetary Radar

    Science.gov (United States)

    Neish, Catherine D.; Carter, Lynn M.

    2015-01-01

    This chapter describes the principles of planetary radar, and the primary scientific discoveries that have been made using this technique. The chapter starts by describing the different types of radar systems and how they are used to acquire images and accurate topography of planetary surfaces and probe their subsurface structure. It then explains how these products can be used to understand the properties of the target being investigated. Several examples of discoveries made with planetary radar are then summarized, covering solar system objects from Mercury to Saturn. Finally, opportunities for future discoveries in planetary radar are outlined and discussed.

  9. Reconfigurable signal processor designs for advanced digital array radar systems

    Science.gov (United States)

    Suarez, Hernan; Zhang, Yan (Rockee); Yu, Xining

    2017-05-01

    The new challenges originated from Digital Array Radar (DAR) demands a new generation of reconfigurable backend processor in the system. The new FPGA devices can support much higher speed, more bandwidth and processing capabilities for the need of digital Line Replaceable Unit (LRU). This study focuses on using the latest Altera and Xilinx devices in an adaptive beamforming processor. The field reprogrammable RF devices from Analog Devices are used as analog front end transceivers. Different from other existing Software-Defined Radio transceivers on the market, this processor is designed for distributed adaptive beamforming in a networked environment. The following aspects of the novel radar processor will be presented: (1) A new system-on-chip architecture based on Altera's devices and adaptive processing module, especially for the adaptive beamforming and pulse compression, will be introduced, (2) Successful implementation of generation 2 serial RapidIO data links on FPGA, which supports VITA-49 radio packet format for large distributed DAR processing. (3) Demonstration of the feasibility and capabilities of the processor in a Micro-TCA based, SRIO switching backplane to support multichannel beamforming in real-time. (4) Application of this processor in ongoing radar system development projects, including OU's dual-polarized digital array radar, the planned new cylindrical array radars, and future airborne radars.

  10. An infectious disease/fever screening radar system which stratifies higher-risk patients within ten seconds using a neural network and the fuzzy grouping method.

    Science.gov (United States)

    Sun, Guanghao; Matsui, Takemi; Hakozaki, Yukiya; Abe, Shigeto

    2015-03-01

    To classify higher-risk influenza patients within 10 s, we developed an infectious disease and fever screening radar system. The system screens infected patients based on vital signs, i.e., respiration rate measured by a radar, heart rate by a finger-tip photo-reflector, and facial temperature by a thermography. The system segregates subjects into higher-risk influenza (HR-I) group, lower-risk influenza (LR-I) group, and non-influenza (Non-I) group using a neural network and fuzzy clustering method (FCM). We conducted influenza screening for 35 seasonal influenza patients and 48 normal control subjects at the Japan Self-Defense Force Central Hospital. Pulse oximetry oxygen saturation (SpO2) was measured as a reference. The system classified 17 subjects into HR-I group, 26 into LR-I group, and 40 into Non-I group. Ten out of the 17 HR-I subjects indicated SpO2 Non-I group. The combination of neural network and FCM achieved efficient detection of higher-risk influenza patients who indicated SpO2 96% within 10 s. Copyright © 2014 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  11. Generalized Load Sharing for Homogeneous Networks of Distributed Environment

    Directory of Open Access Journals (Sweden)

    A. Satheesh

    2008-01-01

    Full Text Available We propose a method for job migration policies by considering effective usage of global memory in addition to CPU load sharing in distributed systems. When a node is identified for lacking sufficient memory space to serve jobs, one or more jobs of the node will be migrated to remote nodes with low memory allocations. If the memory space is sufficiently large, the jobs will be scheduled by a CPU-based load sharing policy. Following the principle of sharing both CPU and memory resources, we present several load sharing alternatives. Our objective is to reduce the number of page faults caused by unbalanced memory allocations for jobs among distributed nodes, so that overall performance of a distributed system can be significantly improved. We have conducted trace-driven simulations to compare CPU-based load sharing policies with our policies. We show that our load sharing policies not only improve performance of memory bound jobs, but also maintain the same load sharing quality as the CPU-based policies for CPU-bound jobs. Regarding remote execution and preemptive migration strategies, our experiments indicate that a strategy selection in load sharing is dependent on the amount of memory demand of jobs, remote execution is more effective for memory-bound jobs, and preemptive migration is more effective for CPU-bound jobs. Our CPU-memory-based policy using either high performance or high throughput approach and using the remote execution strategy performs the best for both CPU-bound and memory-bound job in homogeneous networks of distributed environment.

  12. Comparing Notes: Collaborative Networks, Breeding Environments, and Organized Crime

    Science.gov (United States)

    Hernández, Alejandro

    Collaborative network theory can be useful in refining current understanding of criminal networks and aid in understanding their evolution. Drug trafficking organizations that operate in the region directly north of Colombia’s Valle del Cauca department and the “collection agencies” that operate in the Colombian city of Cali have abandoned hierarchical organizational structures and have become networked-based entities. Through the exposition of Camarinha-Matos and Afsarmanesh’s business networking ideas, this chapter examines the similarities and differences between the application of collaborative networks in licit enterprises, such as small and medium enterprises in Europe, and how the networks might be used by illicit criminal enterprises in Colombia.

  13. Detection of urban environments using advanced land observing satellite phased array type L-band synthetic aperture radar data through different classification techniques

    Science.gov (United States)

    Pradhan, Biswajeet; Abdullahi, Saleh; Seddighi, Younes

    2016-07-01

    Urban environments are very dynamic phenomena, and it is essential to update urban-related information for various applications. In this regard, remotely sensed data have been utilized widely to extract and monitor urban land use and land cover changes. Particularly, synthetic aperture radar (SAR) data, due to several advantages of this technology in comparison to passive sensors, provides better performance especially in tropical regions. However, the methodological approaches for extraction of information from SAR images are another important task that needs to be considered appropriately. This paper attempts to investigate and compare the performance of different image classification techniques for extracting urban areas using advanced land observing satellite phased array type L-band synthetic aperture radar imagery. Several object- [such as rule based (RB), support vector machine (SVM) and K-nearest neighbor (K-NN)] and pixel-based [decision tree (DT)] classification techniques were implemented, and their results were compared in detail. The overall results indicated RB classification performed better than other techniques. Furthermore, DT method, due to its predefined rules, distinguished the land cover classes better than SVM and K-NN, which were based on training datasets. Nevertheless, this study confirms the potential of SAR data and object-based classification techniques in urban detection and land cover mapping.

  14. Performance Analysis of Routing Protocols in Ad-hoc and Sensor Networking Environments

    Directory of Open Access Journals (Sweden)

    L. Gavrilovska

    2009-06-01

    Full Text Available Ad-hoc and sensor networks are becoming an increasingly popular wireless networking concepts lately. This paper analyzes and compares prominent routing schemes in these networking environments. The knowledge obtained can serve users to better understand short range wireless network solutions thus leading to options for implementation in various scenarios. In addition, it should aid researchers develop protocol improvements reliable for the technologies of interest.

  15. Constructing Neuronal Network Models in Massively Parallel Environments

    Directory of Open Access Journals (Sweden)

    Tammo Ippen

    2017-05-01

    Full Text Available Recent advances in the development of data structures to represent spiking neuron network models enable us to exploit the complete memory of petascale computers for a single brain-scale network simulation. In this work, we investigate how well we can exploit the computing power of such supercomputers for the creation of neuronal networks. Using an established benchmark, we divide the runtime of simulation code into the phase of network construction and the phase during which the dynamical state is advanced in time. We find that on multi-core compute nodes network creation scales well with process-parallel code but exhibits a prohibitively large memory consumption. Thread-parallel network creation, in contrast, exhibits speedup only up to a small number of threads but has little overhead in terms of memory. We further observe that the algorithms creating instances of model neurons and their connections scale well for networks of ten thousand neurons, but do not show the same speedup for networks of millions of neurons. Our work uncovers that the lack of scaling of thread-parallel network creation is due to inadequate memory allocation strategies and demonstrates that thread-optimized memory allocators recover excellent scaling. An analysis of the loop order used for network construction reveals that more complex tests on the locality of operations significantly improve scaling and reduce runtime by allowing construction algorithms to step through large networks more efficiently than in existing code. The combination of these techniques increases performance by an order of magnitude and harnesses the increasingly parallel compute power of the compute nodes in high-performance clusters and supercomputers.

  16. Constructing Neuronal Network Models in Massively Parallel Environments.

    Science.gov (United States)

    Ippen, Tammo; Eppler, Jochen M; Plesser, Hans E; Diesmann, Markus

    2017-01-01

    Recent advances in the development of data structures to represent spiking neuron network models enable us to exploit the complete memory of petascale computers for a single brain-scale network simulation. In this work, we investigate how well we can exploit the computing power of such supercomputers for the creation of neuronal networks. Using an established benchmark, we divide the runtime of simulation code into the phase of network construction and the phase during which the dynamical state is advanced in time. We find that on multi-core compute nodes network creation scales well with process-parallel code but exhibits a prohibitively large memory consumption. Thread-parallel network creation, in contrast, exhibits speedup only up to a small number of threads but has little overhead in terms of memory. We further observe that the algorithms creating instances of model neurons and their connections scale well for networks of ten thousand neurons, but do not show the same speedup for networks of millions of neurons. Our work uncovers that the lack of scaling of thread-parallel network creation is due to inadequate memory allocation strategies and demonstrates that thread-optimized memory allocators recover excellent scaling. An analysis of the loop order used for network construction reveals that more complex tests on the locality of operations significantly improve scaling and reduce runtime by allowing construction algorithms to step through large networks more efficiently than in existing code. The combination of these techniques increases performance by an order of magnitude and harnesses the increasingly parallel compute power of the compute nodes in high-performance clusters and supercomputers.

  17. Teaching Network Security in a Virtual Learning Environment

    Science.gov (United States)

    Bergstrom, Laura; Grahn, Kaj J.; Karlstrom, Krister; Pulkkis, Goran; Astrom, Peik

    2004-01-01

    This article presents a virtual course with the topic network security. The course has been produced by Arcada Polytechnic as a part of the production team Computer Networks, Telecommunication and Telecommunication Systems in the Finnish Virtual Polytechnic. The article begins with an introduction to the evolution of the information security…

  18. Bluetooth Roaming for Sensor Network System in Clinical Environment.

    Science.gov (United States)

    Kuroda, Tomohiro; Noma, Haruo; Takase, Kazuhiko; Sasaki, Shigeto; Takemura, Tadamasa

    2015-01-01

    A sensor network is key infrastructure for advancing a hospital information system (HIS). The authors proposed a method to provide roaming functionality for Bluetooth to realize a Bluetooth-based sensor network, which is suitable to connect clinical devices. The proposed method makes the average response time of a Bluetooth connection less than one second by making the master device repeat the inquiry process endlessly and modifies parameters of the inquiry process. The authors applied the developed sensor network for daily clinical activities in an university hospital, and confirmed the stabilitya and effectiveness of the sensor network. As Bluetooth becomes a quite common wireless interface for medical devices, the proposed protocol that realizes Bluetooth-based sensor network enables HIS to equip various clinical devices and, consequently, lets information and communication technologies advance clinical services.

  19. Relative Panoramic Camera Position Estimation for Image-Based Virtual Reality Networks in Indoor Environments

    Science.gov (United States)

    Nakagawa, M.; Akano, K.; Kobayashi, T.; Sekiguchi, Y.

    2017-09-01

    Image-based virtual reality (VR) is a virtual space generated with panoramic images projected onto a primitive model. In imagebased VR, realistic VR scenes can be generated with lower rendering cost, and network data can be described as relationships among VR scenes. The camera network data are generated manually or by an automated procedure using camera position and rotation data. When panoramic images are acquired in indoor environments, network data should be generated without Global Navigation Satellite Systems (GNSS) positioning data. Thus, we focused on image-based VR generation using a panoramic camera in indoor environments. We propose a methodology to automate network data generation using panoramic images for an image-based VR space. We verified and evaluated our methodology through five experiments in indoor environments, including a corridor, elevator hall, room, and stairs. We confirmed that our methodology can automatically reconstruct network data using panoramic images for image-based VR in indoor environments without GNSS position data.

  20. Final Report – Study of Shortwave Spectra in Fully 3D Environment. Synergy Between Scanning Radars and Spectral Radiation Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, Jui-Yuan [University of Reading (United Kingdom)

    2015-09-14

    ARM set out 20 years ago to “close” the radiation problem, that is, to improve radiation models to the point where they could routinely predict the observed spectral radiation fluxes knowing the optical properties of the surface and of gases, clouds and aerosols in the atmosphere. Only then could such radiation models form a proper springboard for global climate model (GCM) parameterizations of spectral radiation. Sustained efforts have more or less achieved that goal with regard to longwave radiation; ASR models now routinely predict ARM spectral longwave radiances to 1–2%. Similar efforts in the shortwave have achieved far less; the successes are mainly for carefully selected 1D stratiform cloud cases. Such cases amount, even with the most optimistic interpretation, to no more than 30% of all cases at SGP. The problem has not been lack of effort but lack of appropriate instruments.The new ARM stimulus-funded instruments, with their new capabilities, will dramatically improve this situation and once again make progress possible on the shortwave problem. The new shortwave spectrometers will provide a reliable, calibrated record including the near infrared – and for other climatic regimes than SGP. The new scanning radars will provide the 3D cloud view, making it possible to tackle fully 3D situations. Thus, our main theme for the project is the understanding and closure of the surface spectral shortwave radiation problem in fully 3D cloud situations by combining the new ARM scanning radars and shortwave spectrometers with the arsenal of radiative transfer tools.

  1. An operating environment for control systems on transputer networks

    NARCIS (Netherlands)

    Tillema, H.G.; Schoute, Albert L.; Wijbrans, K.C.J.; Wijbrans, K.C.J.

    1991-01-01

    The article describes an operating environment for control systems. The environment contains the basic layers of a distributed operating system. The design of this operating environment is based on the requirements demanded by controllers which can be found in complex control systems. Due to the

  2. Study on an Agricultural Environment Monitoring Server System using Wireless Sensor Networks

    OpenAIRE

    Hwang, Jeonghwan; Shin, Changsun; Yoe, Hyun

    2010-01-01

    This paper proposes an agricultural environment monitoring server system for monitoring information concerning an outdoors agricultural production environment utilizing Wireless Sensor Network (WSN) technology. The proposed agricultural environment monitoring server system collects environmental and soil information on the outdoors through WSN-based environmental and soil sensors, collects image information through CCTVs, and collects location information using GPS modules. This collected inf...

  3. Next Generation Enterprise Network Business Continuity: Maintaining Operations In A Compromised Environment

    Science.gov (United States)

    2016-03-01

    ENTERPRISE NETWORK BUSINESS CONTINUITY: MAINTAINING OPERATIONS IN A COMPROMISED ENVIRONMENT by Erik C. Hansen March 2016 Thesis Advisor...in mission resilience and mission assurance engineering [2], [24]. This work explores business continuity in a compromised environment ...are commercially available and are developed by mature companies. Cisco offers collaboration tailored to virtual environments as part of Business

  4. L-band radar scattering from grass

    Science.gov (United States)

    Chauhan, N.; O'Neill, P.; Le Vine, D.; Lang, R.; Khadr, N.

    1992-01-01

    A radar system based on a network analyzer has been developed to study the backscatter from vegetation. The radar is operated at L-band. Radar measurements of a grass field were made in 1991. The radar returns from the grass were measured at three incidence angles. Ground truth and canopy parameters such as blade and stem dimensions, moisture content of the grass and the soil, and blade and stem density, were measured. These parameters are used in a distorted Born approximation model to compute the backscatter coefficients from the grass layer. The model results are compared with the radar data.

  5. Decision Tool for optimal deployment of radar systems

    NARCIS (Netherlands)

    Vogel, M.H.

    1995-01-01

    A Decision Tool for air defence is presented. This Decision Tool, when provided with information about the radar, the environment, and the expected class of targets, informs the radar operator about detection probabilities. This assists the radar operator to select the optimum radar parameters. n

  6. On network representations of antennas inside resonating environments

    Directory of Open Access Journals (Sweden)

    F. Gronwald

    2007-06-01

    Full Text Available We discuss network representations of dipole antennas within electromagnetic cavities. It is pointed out that for a given configuration these representations are not unique. For an efficient evaluation a network representation should be chosen such that it involves as few network elements as possible. The field theoretical analogue of this circumstance is the possibility to express electromagnetic cavities' Green's functions by representations which exhibit different convergence properties. An explicit example of a dipole antenna within a rectangular cavity clarifies the corresponding interrelation between network theory and electromagnetic field theory. As an application, current spectra are calculated for the case that the antenna is nonlinearly loaded and subject to a two-tone excitation.

  7. Directional Networking in GPS Denied Environments - Time Synchronization

    Science.gov (United States)

    2016-03-14

    Directional Networking in GPS Denied Environments—Time Synchronization Derya Cansever and Gilbert Green Army CERDEC Aberdeen Proving Ground MA...when GPS is not available. We show that the Fast RTSR algorithm allows the entire network to achieve time synchronization with convergence time of...RF-based measurements to synchronize time and measure node range.  Satellite Doppler: Using Doppler measurements from multiple satellites along

  8. User Identification Framework in Social Network Services Environment

    Directory of Open Access Journals (Sweden)

    Brijesh BAKARIYA

    2014-01-01

    Full Text Available Social Network Service is a one of the service where people may communicate with one an-other; and may also exchange messages even of any type of audio or video communication. Social Network Service as name suggests a type of network. Such type of web application plays a dominant role in internet technology. In such type of online community, people may share their common interest. Facebook LinkedIn, orkut and many more are the Social Network Service and it is good medium of making link with people having unique or common interest and goals. But the problem of privacy protection is a big issue in today’s world. As social networking sites allows anonymous users to share information of other stuffs. Due to which cybercrime is also increasing to a rapid extent. In this article we preprocessed the web log data of Social Network Services and assemble that data on the basis of image file format like jpg, jpeg, gif, png, bmp etc. and also propose a framework for victim’s identification.

  9. Cooperation in networks where the learning environment differs from the interaction environment.

    Directory of Open Access Journals (Sweden)

    Jianlei Zhang

    Full Text Available We study the evolution of cooperation in a structured population, combining insights from evolutionary game theory and the study of interaction networks. In earlier studies it has been shown that cooperation is difficult to achieve in homogeneous networks, but that cooperation can get established relatively easily when individuals differ largely concerning the number of their interaction partners, such as in scale-free networks. Most of these studies do, however, assume that individuals change their behaviour in response to information they receive on the payoffs of their interaction partners. In real-world situations, subjects do not only learn from their interaction partners, but also from other individuals (e.g. teachers, parents, or friends. Here we investigate the implications of such incongruences between the 'interaction network' and the 'learning network' for the evolution of cooperation in two paradigm examples, the Prisoner's Dilemma game (PDG and the Snowdrift game (SDG. Individual-based simulations and an analysis based on pair approximation both reveal that cooperation will be severely inhibited if the learning network is very different from the interaction network. If the two networks overlap, however, cooperation can get established even in case of considerable incongruence between the networks. The simulations confirm that cooperation gets established much more easily if the interaction network is scale-free rather than random-regular. The structure of the learning network has a similar but much weaker effect. Overall we conclude that the distinction between interaction and learning networks deserves more attention since incongruences between these networks can strongly affect both the course and outcome of the evolution of cooperation.

  10. Integrated Analysis of Environment-driven Operational Effects in Sensor Networks

    Energy Technology Data Exchange (ETDEWEB)

    Park, Alfred J [ORNL; Perumalla, Kalyan S [ORNL

    2007-07-01

    There is a rapidly growing need to evaluate sensor network functionality and performance in the context of the larger environment of infrastructure and applications in which the sensor network is organically embedded. This need, which is motivated by complex applications related to national security operations, leads to a paradigm fundamentally different from that of traditional data networks. In the sensor networks of interest to us, the network dynamics depend strongly on sensor activity, which in turn is triggered by events in the environment. Because the behavior of sensor networks is sensitive to these driving phenomena, the integrity of the sensed observations, measurements and resource usage by the network can widely vary. It is therefore imperative to accurately capture the environmental phenomena, and drive the simulation of the sensor network operation by accounting fully for the environment effects. In this paper, we illustrate the strong, intimate coupling between the sensor network operation and the driving phenomena in their applications with an example sensor network designed to detect and track gaseous plumes.

  11. Low Power Multi-Hop Networking Analysis in Intelligent Environments

    Directory of Open Access Journals (Sweden)

    Josu Etxaniz

    2017-05-01

    Full Text Available Intelligent systems are driven by the latest technological advances in many different areas such as sensing, embedded systems, wireless communications or context recognition. This paper focuses on some of those areas. Concretely, the paper deals with wireless communications issues in embedded systems. More precisely, the paper combines the multi-hop networking with Bluetooth technology and a quality of service (QoS metric, the latency. Bluetooth is a radio license-free worldwide communication standard that makes low power multi-hop wireless networking available. It establishes piconets (point-to-point and point-to-multipoint links and scatternets (multi-hop networks. As a result, many Bluetooth nodes can be interconnected to set up ambient intelligent networks. Then, this paper presents the results of the investigation on multi-hop latency with park and sniff Bluetooth low power modes conducted over the hardware test bench previously implemented. In addition, the empirical models to estimate the latency of multi-hop communications over Bluetooth Asynchronous Connectionless Links (ACL in park and sniff mode are given. The designers of devices and networks for intelligent systems will benefit from the estimation of the latency in Bluetooth multi-hop communications that the models provide.

  12. Low Power Multi-Hop Networking Analysis in Intelligent Environments.

    Science.gov (United States)

    Etxaniz, Josu; Aranguren, Gerardo

    2017-05-19

    Intelligent systems are driven by the latest technological advances in many different areas such as sensing, embedded systems, wireless communications or context recognition. This paper focuses on some of those areas. Concretely, the paper deals with wireless communications issues in embedded systems. More precisely, the paper combines the multi-hop networking with Bluetooth technology and a quality of service (QoS) metric, the latency. Bluetooth is a radio license-free worldwide communication standard that makes low power multi-hop wireless networking available. It establishes piconets (point-to-point and point-to-multipoint links) and scatternets (multi-hop networks). As a result, many Bluetooth nodes can be interconnected to set up ambient intelligent networks. Then, this paper presents the results of the investigation on multi-hop latency with park and sniff Bluetooth low power modes conducted over the hardware test bench previously implemented. In addition, the empirical models to estimate the latency of multi-hop communications over Bluetooth Asynchronous Connectionless Links (ACL) in park and sniff mode are given. The designers of devices and networks for intelligent systems will benefit from the estimation of the latency in Bluetooth multi-hop communications that the models provide.

  13. Network Management Services Based On The Openflow Environment

    Directory of Open Access Journals (Sweden)

    Paweł Wilk

    2014-01-01

    Full Text Available The subject of this article is network management through web service calls, which allows software applications to exert an influence on network traffic. In this manner, software can make independent decisions concerning the direction of requests so that they can be served as soon as possible. This is important because only proper cooperation including all architecture layers can ensure the best performance, especially when software that largely depends on computer networks and utilizes them heavily is involved. To demonstrate that the approach described above is feasible and can be useful at the same time, this article presents a switch-level load balancer developed using OpenFlow. Client software communicates with the balancer through REST web service calls, which are used to provide information on current machine load and its ability to serve incoming requests. The result is a cheap, highly customizable and extremely fast load balancer with considerable potential for further development.

  14. Radar history

    Science.gov (United States)

    Putley, Ernest

    2008-07-01

    The invention of radar, as mentioned in Chris Lavers' article on warship stealth technology (March pp21-25), continues to be a subject of discussion. Here in Malvern we have just unveiled a blue plaque to commemorate the physicist Albert Percival Rowe, who arrived in 1942 as the head of the Telecommunications Research Establishment (TRE), which was the Air Ministry research facility responsible for the first British radar systems.

  15. Design and Test of the Cross-Format Schema Protocol (XFSP) for Networked Virtual Environments

    National Research Council Canada - National Science Library

    Serin, Ekrem

    2003-01-01

    A Networked Virtual Environment (Net-VE) is a distributed software system in which multiple users interact with each other in real time even though these users may be located around the world Zyda 99...

  16. Theoretical framework on selected core issues on conditions for productive learning in networked learning environments

    DEFF Research Database (Denmark)

    Dirckinck-Holmfeld, Lone; Svendsen, Brian Møller; Ponti, Marisa

    The report documents and summarises the elements and dimensions that have been identified to describe and analyse the case studies collected in the Kaleidoscope Jointly Executed Integrating Research Project (JEIRP) on Conditions for productive learning in network learning environments....

  17. The challenge of social networking in the field of environment and health

    Science.gov (United States)

    2012-01-01

    Background The fields of environment and health are both interdisciplinary and trans-disciplinary, and until recently had little engagement in social networking designed to cross disciplinary boundaries. The EU FP6 project HENVINET aimed to establish integrated social network and networking facilities for multiple stakeholders in environment and health. The underlying assumption is that increased social networking across disciplines and sectors will enhance the quality of both problem knowledge and problem solving, by facilitating interactions. Inter- and trans-disciplinary networks are considered useful for this purpose. This does not mean that such networks are easily organized, as openness to such cooperation and exchange is often difficult to ascertain. Methods Different methods may enhance network building. Using a mixed method approach, a diversity of actions were used in order to investigate the main research question: which kind of social networking activities and structures can best support the objective of enhanced inter- and trans-disciplinary cooperation and exchange in the fields of environment and health. HENVINET applied interviews, a role playing session, a personal response system, a stakeholder workshop and a social networking portal as part of the process of building an interdisciplinary and trans-disciplinary network. Results The interviews provided support for the specification of requirements for an interdisciplinary and trans-disciplinary network. The role playing session, the personal response system and the stakeholder workshop were assessed as useful tools in forming such network, by increasing the awareness by different disciplines of other’s positions. The social networking portal was particularly useful in delivering knowledge, but the role of the scientist in social networking is not yet clear. Conclusions The main challenge in the field of environment and health is not so much a lack of scientific problem knowledge, but rather the

  18. The challenge of social networking in the field of environment and health.

    Science.gov (United States)

    van den Hazel, Peter; Keune, Hans; Randall, Scott; Yang, Aileen; Ludlow, David; Bartonova, Alena

    2012-06-28

    The fields of environment and health are both interdisciplinary and trans-disciplinary, and until recently had little engagement in social networking designed to cross disciplinary boundaries. The EU FP6 project HENVINET aimed to establish integrated social network and networking facilities for multiple stakeholders in environment and health. The underlying assumption is that increased social networking across disciplines and sectors will enhance the quality of both problem knowledge and problem solving, by facilitating interactions. Inter- and trans-disciplinary networks are considered useful for this purpose. This does not mean that such networks are easily organized, as openness to such cooperation and exchange is often difficult to ascertain. Different methods may enhance network building. Using a mixed method approach, a diversity of actions were used in order to investigate the main research question: which kind of social networking activities and structures can best support the objective of enhanced inter- and trans-disciplinary cooperation and exchange in the fields of environment and health. HENVINET applied interviews, a role playing session, a personal response system, a stakeholder workshop and a social networking portal as part of the process of building an interdisciplinary and trans-disciplinary network. The interviews provided support for the specification of requirements for an interdisciplinary and trans-disciplinary network. The role playing session, the personal response system and the stakeholder workshop were assessed as useful tools in forming such network, by increasing the awareness by different disciplines of other's positions. The social networking portal was particularly useful in delivering knowledge, but the role of the scientist in social networking is not yet clear. The main challenge in the field of environment and health is not so much a lack of scientific problem knowledge, but rather the ability to effectively communicate, share

  19. Lidar network for atmosphere environment monitoring of the city

    Science.gov (United States)

    Dai, Yongjiang; Zhao, Hongwei; Sun, Fuxing; Zhao, Yu; Chen, Xiangjun

    2000-10-01

    The big city is a center of the economic and political for every country and territory. The population is coarctation$DALindustry is focus and traffic is developed in the city. Especially, there are a lot of factories and cars. Burning coal for heating and life garbage are more too. It is a mostly cause beget atmosphere polluted. The Network can be availability inspects the buildup of the atmosphere, it's 3-D static state distributing and dynamic distributing. Also can be coarsely inspect at the car and helicopter. The network is low cost, high capability and facility using. It is commendably expand for every city.

  20. Radar interferometry persistent scatterer technique

    CERN Document Server

    Kampes, Bert M

    2014-01-01

    This volume is devoted to the Persistent Scatterer Technique, the latest development in radar interferometric data processing. It is the only book on Permanent Scatterer (PS) technique of radar interferometry, and it details a newly developed stochastic model and estimator algorithm to cope with possible problems for the application of the PS technique. The STUN (spatio-temporal unwrapping network) algorithm, developed to cope with these issues in a robust way, is presented and applied to two test sites.

  1. Propagation of radar rainfall uncertainty in urban flood simulations

    Science.gov (United States)

    Liguori, Sara; Rico-Ramirez, Miguel

    2013-04-01

    hydrodynamic sewer network model implemented in the Infoworks software was used to model the rainfall-runoff process in the urban area. The software calculates the flow through the sewer conduits of the urban model using rainfall as the primary input. The sewer network is covered by 25 radar pixels with a spatial resolution of 1 km2. The majority of the sewer system is combined, carrying both urban rainfall runoff as well as domestic and trade waste water [11]. The urban model was configured to receive the probabilistic radar rainfall fields. The results showed that the radar rainfall ensembles provide additional information about the uncertainty in the radar rainfall measurements that can be propagated in urban flood modelling. The peaks of the measured flow hydrographs are often bounded within the uncertainty area produced by using the radar rainfall ensembles. This is in fact one of the benefits of using radar rainfall ensembles in urban flood modelling. More work needs to be done in improving the urban models, but this is out of the scope of this research. The rainfall uncertainty cannot explain the whole uncertainty shown in the flow simulations, and additional sources of uncertainty will come from the structure of the urban models as well as the large number of parameters required by these models. Acknowledgements The authors would like to acknowledge the BADC, the UK Met Office and the UK Environment Agency for providing the various data sets. We also thank Yorkshire Water Services Ltd for providing the urban model. The authors acknowledge the support from the Engineering and Physical Sciences Research Council (EPSRC) via grant EP/I012222/1. References [1] Browning KA, 1978. Meteorological applications of radar. Reports on Progress in Physics 41 761 Doi: 10.1088/0034-4885/41/5/003 [2] Rico-Ramirez MA, Cluckie ID, Shepherd G, Pallot A, 2007. A high-resolution radar experiment on the island of Jersey. Meteorological Applications 14: 117-129. [3] Villarini G, Krajewski WF

  2. Local area network terminal management in support of stock point logistics integrated communications environment (SPLICE)

    OpenAIRE

    Barnes, Jerry D.

    1982-01-01

    Approved for public release; distribution is unlimited This thesis examines the questions of user requirements, design considerations, and network environment for a local area network Terminal Management function in support of the Naval Supply Systems Command's Stock Point Logistics Integrated Communications Environment (SPLICE). Criteria are developed from this examination. They include process-process communication, virtual terminal, and user defined screen capabilities as well as a ne...

  3. Mobility management for highly mobile users and vehicular networks in heterogeneous environments

    OpenAIRE

    Andersson, Karl; Åhlund, Christer; Gukhool, Balkrishna Sharma; Cherkaoui, Soumaya

    2008-01-01

      With the recent developments in wireless networks, different radio access technologies are used in different places depending on capacity in terms of throughput, cell size, scalability etc. In this context, mobile users, and in particular highly mobile users and vehicular networks, will see an increasing number and variety of wireless access points enabling Internet connectivity. Such a heterogeneous networking environment needs, however, an efficient mobility management scheme offering ...

  4. Scholarly Communication in the Network Environment: Issues of Principle, Policy and Practice.

    Science.gov (United States)

    Kahin, Brian

    1992-01-01

    Discussion of legal and ethical issues raised by the growth of research networking focuses on two general areas: (1) communication, prepublication, and publication; and (2) the network as a distribution environment. Issues considered include joint authorship, rights in computer conferencing, derivative works, control of dissemination, site…

  5. Using a Classification of Psychological Experience in Social-Networking Sites as a Virtual Learning Environment

    Science.gov (United States)

    Onibokun, Joseph; van Schaik, Paul

    2012-01-01

    With over 800 million users worldwide, the global importance of Facebook as a social-networking platform is beyond doubt. This popularity, particularly among university-students, has encouraged research to explore ways in which social networking can be adapted into virtual learning environments. In particular, this study uses the think-aloud…

  6. The Effect of Social Interaction on Learning Engagement in a Social Networking Environment

    Science.gov (United States)

    Lu, Jie; Churchill, Daniel

    2014-01-01

    This study investigated the impact of social interactions among a class of undergraduate students on their learning engagement in a social networking environment. Thirteen undergraduate students enrolled in a course in a university in Hong Kong used an Elgg-based social networking platform throughout a semester to develop their digital portfolios…

  7. Modelling Mobility in Mobile AD-HOC Network Environments ...

    African Journals Online (AJOL)

    We show how to implement the random waypoint mobility model for ad-hoc networks without pausing, through a more efficient and reliable computer simulation, using MATrix LABoratory 7.5.0 (R2007b). Simulation results obtained verify the correctness of the model. Keywords : Stationary, random waypoint, simulation, ...

  8. Information Superiority/Battle Command (Network Centric Warfare Environment)

    Science.gov (United States)

    2004-06-01

    on the Move (BCOTM). To this end a multiplicity of subtasks have been articulated to include: 1) Evaluate future data radio, wireless , personal...Multinational Communcations Systems. Requirement for Dedicated All Weather Communications Relay platforms. Requirement for Higher level of Networking

  9. Cooperation in networks where the learning environment differs from the interaction environment

    NARCIS (Netherlands)

    Zhang, Jianlei; Zhang, Chunyan; Chu, Tianguang; Weissing, Franz J.

    2014-01-01

    We study the evolution of cooperation in a structured population, combining insights from evolutionary game theory and the study of interaction networks. In earlier studies it has been shown that cooperation is difficult to achieve in homogeneous networks, but that cooperation can get established

  10. Modeling cellular networks in fading environments with dominant specular components

    KAUST Repository

    AlAmmouri, Ahmad

    2016-07-26

    Stochastic geometry (SG) has been widely accepted as a fundamental tool for modeling and analyzing cellular networks. However, the fading models used with SG analysis are mainly confined to the simplistic Rayleigh fading, which is extended to the Nakagami-m fading in some special cases. However, neither the Rayleigh nor the Nakagami-m accounts for dominant specular components (DSCs) which may appear in realistic fading channels. In this paper, we present a tractable model for cellular networks with generalized two-ray (GTR) fading channel. The GTR fading explicitly accounts for two DSCs in addition to the diffuse components and offers high flexibility to capture diverse fading channels that appear in realistic outdoor/indoor wireless communication scenarios. It also encompasses the famous Rayleigh and Rician fading as special cases. To this end, the prominent effect of DSCs is highlighted in terms of average spectral efficiency. © 2016 IEEE.

  11. Weather Radar Stations

    Data.gov (United States)

    Department of Homeland Security — These data represent Next-Generation Radar (NEXRAD) and Terminal Doppler Weather Radar (TDWR) weather radar stations within the US. The NEXRAD radar stations are...

  12. Urban transport, the environment and the network society

    DEFF Research Database (Denmark)

    Hansen, Carsten Jahn

    2005-01-01

    succeeded over conventional and more hierarchical ways of public policymaking. As such, these cases offer illuminating examples of collaborative dialogue, expressed through networks in which argumentative approaches and increased reflexivity about the ´rules of the game´ have been central elements. Finally......, the paper discusses the extent to which this should amount to a call for deliberative approaches and new policy procedures. how...

  13. Personal Computer Local Area Network Security in an Academic Environment

    Science.gov (United States)

    1989-12-01

    AND JUSTIFICATION The San Francisco Examiner ran an article by John Dvorak on Sunday August 6th titled "Viruses Make Me Sick". The author speaks of the...humidity or foreign object destruction (e.g. a drink spilled into the keyboard ). Unfortunately, these areas can be tough to guard against. User training is...inserted into a floppy drive or a favorite soft drink is placed two inches from a keyboard . Instead, upon introduc- tion to the network labs

  14. Various Effects of Embedded Intrapulse Communications on Pulsed Radar

    Science.gov (United States)

    2017-06-01

    impact of an interfering communications signal on the range-Doppler map of a pulse Doppler radar is investigated. The perspective of a radar operator in a...perspective of a radar operator in a maritime environment is also considered. In all cases, the communications signal is parameterized by the radar - to...utilize the S-band of around 3 GHz, where many maritime radars operate [1]. The two broad categories for how these two signals could be separated from

  15. Feasibility analysis of WDM links for radar applications

    Directory of Open Access Journals (Sweden)

    D. Meena

    2015-03-01

    Full Text Available Active phased array antennas enhances the performance of modern radars by using multiple low power transmit/receive modules in place of a high power transmitter in conventional radars. Fully distributed phased array radars demand the distribution of various signals in radio frequency (RF and digital domain for real time operation. This is normally achieved through complex and bulky coaxial distribution networks. In this work, we intend to tap the inherent advantages of fiber links with wavelength division multiplexed (WDM technology and a feasibility study to adapt these links for radar applications is carried out. This is done by analysing various parameters like amplitude, delay, frequency and phase variation response of various radar waveforms over WDM links. This also includes performance evaluation of non-linear frequency modulation (NLFM signals, known for better signal to noise ratio (SNR to specific side lobe levels. NLFM waveforms are further analysed using pulse compression (PC technique. Link evaluation is also carried out using a standard simulation environment and is then experimentally verified with other waveforms like RF continuous wave (CW, pulsed RF and digital signals. Synchronization signals are generated from this variable duty cycle digital signals during real time radar operation. During evaluation of digital signals, variable transient effects for different duty cycles are observed from an amplifier configuration. A suppression method is proposed to eliminate this transient effects. Further, the link delay response is investigated using different lengths of fiber spools. It can be inferred from the experimental results that WDM links are capable of handling various signals significant to radar applications.

  16. Interaction Network Estimation: Predicting Problem-Solving Diversity in Interactive Environments

    Science.gov (United States)

    Eagle, Michael; Hicks, Drew; Barnes, Tiffany

    2015-01-01

    Intelligent tutoring systems and computer aided learning environments aimed at developing problem solving produce large amounts of transactional data which make it a challenge for both researchers and educators to understand how students work within the environment. Researchers have modeled student-tutor interactions using complex networks in…

  17. Research on backbone node deployment for Wireless Mesh Networks in dynamic environments

    Science.gov (United States)

    Li, Meiyi; Cao, Shengling

    2017-08-01

    Wireless Mesh Network is a type of wireless networks in which demands of bandwidth for users has mobility. The backbone node placement of wireless mesh networks in a dynamic scenario is investigated, and the TSDPSO algorithm is used to adapt the dynamic environment, which updates node deployment location to adapt to changes in demand if it detects environmental changes at the beginning of the cycle time. In order to meet the demands of bandwidth for users and network connectivity, particle swarm optimization algorithm is employed to select the gateway location, then nodes to the backbone network is added constantly until all requirement is covered. The experimental results show that algorithm could get effective solution in dynamic environment.

  18. Impact of the environment and the topology on the performance of hierarchical body area networks

    Directory of Open Access Journals (Sweden)

    Ferrari Gianluigi

    2011-01-01

    Full Text Available Abstract Personal area networks and, more specifically, body area networks (BANs are key building blocks of future generation networks and of the Internet of Things as well. In this article, we present a novel analytical framework for network performance analysis of body sensor networks with hierarchical (tree topologies. This framework takes into account the specificities of the on-body channel modeling and the impact of the surrounding environment. The obtained results clearly highlight the differences between indoor and outdoor scenarios, and provide several insights on BAN design and analysis. In particular, it will be shown that the BAN topology should be selected according to the foreseen medical application and the deployment environment.

  19. Proposed Network Intrusion Detection System ‎In Cloud Environment Based on Back ‎Propagation Neural Network

    Directory of Open Access Journals (Sweden)

    Shawq Malik Mehibs

    2017-12-01

    Full Text Available Cloud computing is distributed architecture, providing computing facilities and storage resource as a service over the internet. This low-cost service fulfills the basic requirements of users. Because of the open nature and services introduced by cloud computing intruders impersonate legitimate users and misuse cloud resource and services. To detect intruders and suspicious activities in and around the cloud computing environment, intrusion detection system used to discover the illegitimate users and suspicious action by monitors different user activities on the network .this work proposed based back propagation artificial neural network to construct t network intrusion detection in the cloud environment. The proposed module evaluated with kdd99 dataset the experimental results shows promising approach to detect attack with high detection rate and low false alarm rate

  20. Designing for Learning: Online Social Networks as a Classroom Environment

    Science.gov (United States)

    Casey, Gail; Evans, Terry

    2011-01-01

    This paper deploys notions of emergence, connections, and designs for learning to conceptualize high school students' interactions when using online social media as a learning environment. It makes links to chaos and complexity theories and to fractal patterns as it reports on a part of the first author's action research study, conducted while she…

  1. Policy interpretation network on children's health and environment.

    NARCIS (Netherlands)

    Hazel, P.J. van den; Zuurbier, M.; Bistrup, M.L.

    2006-01-01

    Aim: The main objective of PINCHE is to provide policy recommendations aiming at protecting children's health and environment based on completed scientific research. The project focused on four themes: indoor and outdoor air pollutants, carcinogens, neurotoxicants, and noise. The data were evaluated

  2. A Generic Context Management Framework for Personal Networking Environments

    DEFF Research Database (Denmark)

    Sanchez, Luis; Olsen, Rasmus Løvenstein; Bauer, Martin

    2006-01-01

    In this paper we introduce a high level architecture for a context management system for Personal Networks (PN). The main objective of the Context Management Framework (CMF) described in this paper is to support the interactions between context information sources and context aware components...... on their computational capabilities and their role within the system. We differentiate between Basic Context Nodes (BCN), Enhanced Context Nodes (ECN) and Context Management Nodes (CMN) within the CMF. CMNs operate on two levels, i.e., local/cluster level and PN level. In the paper we also describe how these entities...

  3. Regional Understanding and Unity of Effort: Applying the Global SOF Network in Future Operating Environments Communications

    Science.gov (United States)

    2016-12-07

    and Afghanistan in newly relevant operating environments is to invite failure. In today’s globalized world , clear dividing lines between...PRISM 6, no. 3 FEATURES | 49 Regional Understanding and Unity of Effort Applying the Global SOF Network in Future Operating Environments ...the challenges and social diversity characteristic of today’s global operating environment . In con- trast, FAOs often lack tactical experience rela

  4. Realtime Automation Networks in moVing industrial Environments

    Directory of Open Access Journals (Sweden)

    Rafael Leidinger

    2012-04-01

    Full Text Available The radio-based wireless data communication has made the realization of new technical solutions possible in many fields of the automation technology (AT. For about ten years, a constant disproportionate growth of wireless technologies can be observed in the automation technology. However, it shows that especially for the AT, conven-tional technologies of office automation are unsuitable and/or not manageable. The employment of mobile ser-vices in the industrial automation technology has the potential of significant cost and time savings. This leads to an increased productivity in various fields of the AT, for example in the factory and process automation or in production logistics. In this paper technologies and solu-tions for an automation-suited supply of mobile wireless services will be introduced under the criteria of real time suitability, IT-security and service orientation. Emphasis will be put on the investigation and develop-ment of wireless convergence layers for different radio technologies, on the central provision of support services for an easy-to-use, central, backup enabled management of combined wired / wireless networks and on the study on integrability in a Profinet real-time Ethernet network [1].

  5. Messenger in The Barn: networking in a learning environment

    Directory of Open Access Journals (Sweden)

    Malcolm Rutter

    2009-12-01

    Full Text Available This case study describes the use of a synchronous communication application (MSN Messenger in a large academic computing environment. It draws on data from interviews, questionnaires and student marks to examine the link between use of the application and success measured through module marks. The relationship is not simple. Total abstainers and heavy users come out best, while medium level users do less well, indicating the influence of two factors. The discussion section suggests possible factors. The study also highlights the benefits of support and efficiency of communication that the application brings. Although there have been many studies of synchronous communication tool use in the office and in social life, this is one of the first to examine its informal use in an academic environment.

  6. Koncept softverskog radara / Software radar concept

    Directory of Open Access Journals (Sweden)

    Dejan Ivković

    2007-01-01

    Full Text Available U ovom radu analiziran je koncept softverskog radara. Zbog velike fleksibilnosti softverski radar ima mnoge prednosti u odnosu na konvencionalne radare. Takođe, održavanje softverskog radarskog sistema je mnogo jeftinije. Predstavljena je teorijska i tehnološka osnovica softverskog radara i opisana njegova arhitektura, kao i način organizacije njegove mreže. Ploča DSP (Digital Signal Processing predstavlja centralni deo softverskog radara, pa je detaljno predstavljena njena uloga. Opisana je platforma quatro 6x i akviziciona kartica PCI-9812/10. Rezultat sprovedene tehno-ekonomske analize pokazuje da je za stvarnu implementaciju projektovanih softverskih modula radarskog prijemnika u konkretni konvencionalni radar potrebno izdvojiti oko 20 000 USD, što je mnogo manje od cene modernih radarskih sistema. / Software radar concept is described in this paper. Because of high level of flexibility software radar has many advantages in aspect to conventional radar. Also, service of the software radar system is much cheaper. Theoretical and technical basis of software radar is presented and its architecture is proposed. Organization method of the software radar network is specified. DSP (Digital, signal Processing board is central part of the software radar and its role is described in details. Quatro 6x platform and PCI-9812/10 acquisition card are described. Result of the given techno-economical analysis approves that it is necessary to invest around 20 000$ and that is much less than the price of modern radar systems.

  7. Environment Based Secure Transfer of Data in Wireless Sensor Networks

    OpenAIRE

    Vidhya, B.; Joseph, Mary; Girinath, D. Rajini; Malathi, A.

    2015-01-01

    Most critical sensor readings (Top-k Monitoring) in environment monitoring system are important to many wireless sensor applications. In such applications, sensor nodes transmit the data continuously for a specific time period to the storage nodes. It is responsible for transferring the received results to the Authority on Top-k Query request from them. Dummy data's were added into the original text data to secure the data against adversary in case of hacking the sensor and storage nodes. If ...

  8. Bistatic radar

    CERN Document Server

    Willis, Nick

    2004-01-01

    Annotation his book is a major extension of a chapter on bistatic radar written by the author for the Radar Handbook, 2nd edition, edited by Merrill Skolnik. It provides a history of bistatic systems that points out to potential designers the applications that have worked and the dead-ends not worth pursuing. The text reviews the basic concepts and definitions, and explains the mathematical development of relationships, such as geometry, Ovals of Cassini, dynamic range, isorange and isodoppler contours, target doppler, and clutter doppler spread.Key Features * All development and analysis are

  9. Automated Extraction of Gravity Wave Signatures from the Super Dual Auroral Radar Network (SuperDARN) Database Using Spatio-Temporal Process Discovery Algorithms

    Science.gov (United States)

    Baker, J. B.; Ramakrishnan, N.; Ruohoniemi, J. M.; Hossain, M.; Ribeiro, A.

    2011-12-01

    A major challenge in space physics research is the automated extraction of recurrent features from multi-dimensional datasets which tend to be irregularly gridded in both space and time. In many cases, the complexity of the datasets impedes their use by scientists who are often times most interested in extracting a simple time-series of higher level data product that can be easily compared with other measurements. As such, the collective archive of space physics measurements is vastly under-utilized at the present time. Application of cutting-edge computer-aided data mining and knowledge discovery techniques has the potential to improve this situation by making space physics datasets much more accessible to the scientific user community and accelerating the rate of research and collaboration. As a first step in this direction, we are applying the principles of feature extraction, sub-clustering and motif mining to the analysis of HF backscatter measurements from the Super Dual Auroral Radar Network (SuperDARN). The SuperDARN database is an ideal test-bed for development of space physics data mining algorithms because: (1) there is a richness of geophysical phenomena manifested in the data; (2) the data is multi-dimensional and exhibits a high degree of spatiotemporal sparseness; and (3) some of the radars have been operating continuously with infrequent outages for more than 25 years. In this presentation we discuss results obtained from the application of new data mining algorithms designed specifically to automate the extraction of gravity wave signatures from the SuperDARN database. In particular, we examine the occurrence statistics of gravity waves as a function of latitude, local time, and geomagnetic conditions.

  10. Radar research at the University of Kansas

    Science.gov (United States)

    Blunt, Shannon D.; Allen, Christopher; Arnold, Emily; Hale, Richard; Hui, Rongqing; Keshmiri, Shahriar; Leuschen, Carlton; Li, Jilu; Paden, John; Rodriguez-Morales, Fernando; Salandrino, Alessandro; Stiles, James

    2017-05-01

    Radar research has been synonymous with the University of Kansas (KU) for over half a century. As part of this special session organized to highlight significant radar programs in academia, this paper surveys recent and ongoing work at KU. This work encompasses a wide breadth of sensing applications including the remote sensing of ice sheets, autonomous navigation methods for unmanned aerial vehicles (UAVs), novel laser radar capabilities, detection of highenergy cosmic rays using bistatic radar, different forms of waveform diversity such as MIMO radar and pulse agility, and various radar-embedded communication methods. The results of these efforts impact our understanding of the changing nature of the environment, address the proliferation of unmanned systems in the US airspace, realize new sensing modalities enabled by the joint consideration of electromagnetics and signal processing, and greater facilitate radar operation in an increasingly congested and contested spectrum.

  11. Community and Social Network Sites as Technology Enhanced Learning Environments

    DEFF Research Database (Denmark)

    Ryberg, Thomas; Christiansen, Ellen

    2008-01-01

    This paper examines the affordance of the Danish social networking site Mingler.dk for peer-to-peer learning and development. With inspiration from different theoretical frameworks, the authors argue how learning and development in such social online systems can be conceptualised and analysed....... Theoretically the paper defines development in accordance with Vygotsky's concept of the zone of proximal development, and learning in accordance with Wenger's concept of communities of practice. The authors suggest analysing the learning and development taking place on Mingler.dk by using these concepts...... supplemented by the notion of horizontal learning adopted from Engestrm and Wenger. Their analysis shows how horizontal learning happens by crossing boundaries between several sites of engagement, and how the actors' multiple membership enables the community members to draw on a vast amount of resources from...

  12. Compressive Sensing for MIMO Radar

    CERN Document Server

    Yu, Yao; Poor, H Vincent

    2009-01-01

    Multiple-input multiple-output (MIMO) radar systems have been shown to achieve superior resolution as compared to traditional radar systems with the same number of transmit and receive antennas. This paper considers a distributed MIMO radar scenario, in which each transmit element is a node in a wireless network, and investigates the use of compressive sampling for direction-of-arrival (DOA) estimation. According to the theory of compressive sampling, a signal that is sparse in some domain can be recovered based on far fewer samples than required by the Nyquist sampling theorem. The DOA of targets form a sparse vector in the angle space, and therefore, compressive sampling can be applied for DOA estimation. The proposed approach achieves the superior resolution of MIMO radar with far fewer samples than other approaches. This is particularly useful in a distributed scenario, in which the results at each receive node need to be transmitted to a fusion center for further processing.

  13. Network-based collaborative research environment LDRD final report

    Energy Technology Data Exchange (ETDEWEB)

    Davies, B.R.; McDonald, M.J.

    1997-09-01

    The Virtual Collaborative Environment (VCE) and Distributed Collaborative Workbench (DCW) are new technologies that make it possible for diverse users to synthesize and share mechatronic, sensor, and information resources. Using these technologies, university researchers, manufacturers, design firms, and others can directly access and reconfigure systems located throughout the world. The architecture for implementing VCE and DCW has been developed based on the proposed National Information Infrastructure or Information Highway and a tool kit of Sandia-developed software. Further enhancements to the VCE and DCW technologies will facilitate access to other mechatronic resources. This report describes characteristics of VCE and DCW and also includes background information about the evolution of these technologies.

  14. Radar detection

    CERN Document Server

    DiFranco, Julius

    2004-01-01

    This book presents a comprehensive tutorial exposition of radar detection using the methods and techniques of mathematical statistics. The material presented is as current and useful to today's engineers as when the book was first published by Prentice-Hall in 1968 and then republished by Artech House in 1980. The book is divided into six parts.

  15. A Neural Network Approach to Fluid Quantity Measurement in Dynamic Environments

    CERN Document Server

    Terzic, Edin; Nagarajah, Romesh; Alamgir, Muhammad

    2012-01-01

    Sloshing causes liquid to fluctuate, making accurate level readings difficult to obtain in dynamic environments. The measurement system described uses a single-tube capacitive sensor to obtain an instantaneous level reading of the fluid surface, thereby accurately determining the fluid quantity in the presence of slosh. A neural network based classification technique has been applied to predict the actual quantity of the fluid contained in a tank under sloshing conditions.   In A neural network approach to fluid quantity measurement in dynamic environments, effects of temperature variations and contamination on the capacitive sensor are discussed, and the authors propose that these effects can also be eliminated with the proposed neural network based classification system. To examine the performance of the classification system, many field trials were carried out on a running vehicle at various tank volume levels that range from 5 L to 50 L. The effectiveness of signal enhancement on the neural network base...

  16. Organizational structure and communication networks in a university environment.

    Science.gov (United States)

    Mathiesen, Joachim; Jamtveit, Bjørn; Sneppen, Kim

    2010-07-01

    The "six degrees of separation" between any two individuals on Earth has become emblematic of the "small world" theme, even though the information conveyed via a chain of human encounters decays very rapidly with increasing chain length, and diffusion of information via this process may be very inefficient in large human organizations. The information flow on a communication network in a large organization, the University of Oslo, has been studied by analyzing email records. The records allow for quantification of communication intensity across organizational levels and between organizational units (referred to as "modules"). We find that the number of email messages within modules scales with module size to the power of 1.29±.06 , and the frequency of communication between individuals decays exponentially with the number of links required upward in the organizational hierarchy before they are connected. Our data also indicates that the number of messages sent by administrative units is proportional to the number of individuals at lower levels in the administrative hierarchy, and the "divergence of information" within modules is associated with this linear relationship. The observed scaling is consistent with a hierarchical system in which individuals far apart in the organization interact little with each other and receive a disproportionate number of messages from higher levels in the administrative hierarchy.

  17. Interception of LPI radar signals

    Science.gov (United States)

    Lee, Jim P.

    1991-11-01

    Most current radars are designed to transmit short duration pulses with relatively high peak power. These radars can be detected easily by the use of relatively modest EW intercept receivers. Three radar functions (search, anti-ship missile (ASM) seeker, and navigation) are examined to evaluate the effectiveness of potential low probability of intercept (LPI) techniques, such as waveform coding, antenna profile control, and power management that a radar may employ against current Electronic Warfare (EW) receivers. The general conclusion is that it is possible to design a LPI radar which is effective against current intercept EW receivers. LPI operation is most easily achieved at close ranges and against a target with a large radar cross section. The general system sensitivity requirement for the detection of current and projected LPI radars is found to be on the order of -100 dBmi which cannot be met by current EW receivers. Finally, three potential LPI receiver architectures, using channelized, superhet, and acousto-optic receivers with narrow RF and video bandwidths are discussed. They have shown some potential in terms of providing the sensitivity and capability in an environment where both conventional and LPI signals are present.

  18. Simulation Model of Logistic Support to Isolated Airspace Smveillance Radar Stations

    Directory of Open Access Journals (Sweden)

    Tomislav Crnković

    2008-03-01

    Full Text Available A simulation model of the radar network operation of fivemilitary radar stations has been developed. Simulation waspeiformed in GPSS language and contains the time of operationof five radars through a period of one year, time of plannedpreventive maintenance, irregularities, time of corrective maintenanceand maintenance team(s. The simulation shows theinfluence of the number of maintenance teams on the availabilityof each radar and presents a good orienteering point fordefining the optimal model of preventive and corrective maintenanceof the radar network.

  19. Towards adaptive security for convergent wireless sensor networks in beyond 3G environments

    DEFF Research Database (Denmark)

    Mitseva, Anelia; Aivaloglou, Efthimia; Marchitti, Maria-Antonietta

    2010-01-01

    The integration of wireless sensor networks with different network systems gives rise to many research challenges to ensure security, privacy and trust in the overall architecture. The main contribution of this paper is a generic security, privacy and trust framework providing context...... environments. Performance evaluation results demonstrate the feasibility and estimate the benefits of the security framework for a variety of scenarios. Copyright (C) 2008 John Wiley & Sons, Ltd....

  20. Government information collections in the networked environment new issues and models

    CERN Document Server

    Cheverie, Joan F

    2013-01-01

    This insightful book explores the challenging issues related to effective access to government information.Amidst all the chaos of today's dynamic information transition period, the only constants related to government information are change and inconsistency, yet with Government Information Collections in the Networked Environment: New Issues and Models, you will defeat the challenging issues and take advantage of the opportunities that networked government information collections have to offer. This valuable book gives you a fresh opportunity to rethink collecting activities and to

  1. An Environment IoT Sensor Network for Monitoring the Environment

    Science.gov (United States)

    Martinez, K.; Hart, J. K.; Bragg, O.; Black, A.; Bader, S.; Basford, P. J.; Bragg, G. M.; Fabre, A.

    2016-12-01

    The Internet of Things is a term which has emerged to describe the increase of Internet connectivity of everyday objects. While wireless sensor networks have developed highly energy efficient designs they need a step-change in their interoperability and usability to become more commonly used in Earth Science. IoT techniques can bring many of these advances while reusing some of the technologies developed for low power sensing. Here we concentrate on developing effective use of internet protocols throughout a low power sensor network. This includes 6LowPAN to provide a mesh IPv6 network, 40mW 868 MHz CC1120 radio transceivers to save power but provide kilometre range, a CC2538 ARM® Cortex®-M3 as main processor and CoAP to provide a binary HTTP-like interface to the nodes. We discuss in detail a system we deployed to monitor periglacial, peat and fluvial processes in the Scottish Highlands. The system linked initial nodes 3km away further up the mountain 2km away and used a CoAP GET sequence from a base station in the valley to gather the data. The IPv6 addressing and tunnelling allowed direct connectivity to desktops in Southampton. This provides insights into how the combination of low power techniques and emerging internet standards will bring advantages in interoperability, heterogeneity, usability and maintainability.

  2. Lessons learned on solar powered wireless sensor network deployments in urban, desert environments

    KAUST Repository

    Dehwah, Ahmad H.

    2015-05-01

    The successful deployment of a large scale solar powered wireless sensor network in an urban, desert environment is a very complex task. Specific cities of such environments cause a variety of operational problems, ranging from hardware faults to operational challenges, for instance due to the high variability of solar energy availability. Even a seemingly functional sensor network created in the lab does not guarantee reliable long term operation, which is absolutely necessary given the cost and difficulty of accessing sensor nodes in urban environments. As part of a larger traffic flow wireless sensor network project, we conducted several deployments in the last two years to evaluate the long-term performance of solar-powered urban wireless sensor networks in a desert area. In this article, we share our experiences in all domains of sensor network operations, from the conception of hardware to post-deployment analysis, including operational constraints that directly impact the software that can be run. We illustrate these experiences using numerous experimental results, and present multiple unexpected operational problems as well as some possible solutions to address them. We also show that current technology is far from meeting all operational constraints for these demanding applications, in which sensor networks are to operate for years to become economically appealing.

  3. Collaborative Service Selection via Ensemble Learning in Mixed Mobile Network Environments

    Directory of Open Access Journals (Sweden)

    Yuyu Yin

    2017-07-01

    Full Text Available Mobile Service selection is an important but challenging problem in service and mobile computing. Quality of service (QoS predication is a critical step in service selection in 5G network environments. The traditional methods, such as collaborative filtering (CF, suffer from a series of defects, such as failing to handle data sparsity. In mobile network environments, the abnormal QoS data are likely to result in inferior prediction accuracy. Unfortunately, these problems have not attracted enough attention, especially in a mixed mobile network environment with different network configurations, generations, or types. An ensemble learning method for predicting missing QoS in 5G network environments is proposed in this paper. There are two key principles: one is the newly proposed similarity computation method for identifying similar neighbors; the other is the extended ensemble learning model for discovering and filtering fake neighbors from the preliminary neighbors set. Moreover, three prediction models are also proposed, two individual models and one combination model. They are used for utilizing the user similar neighbors and servicing similar neighbors, respectively. Experimental results conducted in two real-world datasets show our approaches can produce superior prediction accuracy.

  4. RELATIVE PANORAMIC CAMERA POSITION ESTIMATION FOR IMAGE-BASED VIRTUAL REALITY NETWORKS IN INDOOR ENVIRONMENTS

    Directory of Open Access Journals (Sweden)

    M. Nakagawa

    2017-09-01

    Full Text Available Image-based virtual reality (VR is a virtual space generated with panoramic images projected onto a primitive model. In imagebased VR, realistic VR scenes can be generated with lower rendering cost, and network data can be described as relationships among VR scenes. The camera network data are generated manually or by an automated procedure using camera position and rotation data. When panoramic images are acquired in indoor environments, network data should be generated without Global Navigation Satellite Systems (GNSS positioning data. Thus, we focused on image-based VR generation using a panoramic camera in indoor environments. We propose a methodology to automate network data generation using panoramic images for an image-based VR space. We verified and evaluated our methodology through five experiments in indoor environments, including a corridor, elevator hall, room, and stairs. We confirmed that our methodology can automatically reconstruct network data using panoramic images for image-based VR in indoor environments without GNSS position data.

  5. Applications of wireless sensor networks in marine environment monitoring: a survey.

    Science.gov (United States)

    Xu, Guobao; Shen, Weiming; Wang, Xianbin

    2014-09-11

    With the rapid development of society and the economy, an increasing number of human activities have gradually destroyed the marine environment. Marine environment monitoring is a vital problem and has increasingly attracted a great deal of research and development attention. During the past decade, various marine environment monitoring systems have been developed. The traditional marine environment monitoring system using an oceanographic research vessel is expensive and time-consuming and has a low resolution both in time and space. Wireless Sensor Networks (WSNs) have recently been considered as potentially promising alternatives for monitoring marine environments since they have a number of advantages such as unmanned operation, easy deployment, real-time monitoring, and relatively low cost. This paper provides a comprehensive review of the state-of-the-art technologies in the field of marine environment monitoring using wireless sensor networks. It first describes application areas, a common architecture of WSN-based oceanographic monitoring systems, a general architecture of an oceanographic sensor node, sensing parameters and sensors, and wireless communication technologies. Then, it presents a detailed review of some related projects, systems, techniques, approaches and algorithms. It also discusses challenges and opportunities in the research, development, and deployment of wireless sensor networks for marine environment monitoring.

  6. Impact of indoor environment on path loss in body area networks.

    Science.gov (United States)

    Hausman, Sławomir; Januszkiewicz, Łukasz

    2014-10-20

    In this paper the influence of an example indoor environment on narrowband radio channel path loss for body area networks operating around 2.4 GHz is investigated using computer simulations and on-site measurements. In contrast to other similar studies, the simulation model included both a numerical human body phantom and its environment-room walls, floor and ceiling. As an example, radio signal attenuation between two different configurations of transceivers with dipole antennas placed in a direct vicinity of a human body (on-body scenario) is analyzed by computer simulations for several types of reflecting environments. In the analyzed case the propagation environments comprised a human body and office room walls. As a reference environment for comparison, free space with only a conducting ground plane, modelling a steel mesh reinforced concrete floor, was chosen. The transmitting and receiving antennas were placed in two on-body configurations chest-back and chest-arm. Path loss vs. frequency simulation results obtained using Finite Difference Time Domain (FDTD) method and a multi-tissue anthropomorphic phantom were compared to results of measurements taken with a vector network analyzer with a human subject located in an average-size empty cuboidal office room. A comparison of path loss values in different environments variants gives some qualitative and quantitative insight into the adequacy of simplified indoor environment model for the indoor body area network channel representation.

  7. Applications of Wireless Sensor Networks in Marine Environment Monitoring: A Survey

    Directory of Open Access Journals (Sweden)

    Guobao Xu

    2014-09-01

    Full Text Available With the rapid development of society and the economy, an increasing number of human activities have gradually destroyed the marine environment. Marine environment monitoring is a vital problem and has increasingly attracted a great deal of research and development attention. During the past decade, various marine environment monitoring systems have been developed. The traditional marine environment monitoring system using an oceanographic research vessel is expensive and time-consuming and has a low resolution both in time and space. Wireless Sensor Networks (WSNs have recently been considered as potentially promising alternatives for monitoring marine environments since they have a number of advantages such as unmanned operation, easy deployment, real-time monitoring, and relatively low cost. This paper provides a comprehensive review of the state-of-the-art technologies in the field of marine environment monitoring using wireless sensor networks. It first describes application areas, a common architecture of WSN-based oceanographic monitoring systems, a general architecture of an oceanographic sensor node, sensing parameters and sensors, and wireless communication technologies. Then, it presents a detailed review of some related projects, systems, techniques, approaches and algorithms. It also discusses challenges and opportunities in the research, development, and deployment of wireless sensor networks for marine environment monitoring.

  8. Applications of Wireless Sensor Networks in Marine Environment Monitoring: A Survey

    Science.gov (United States)

    Xu, Guobao; Shen, Weiming; Wang, Xianbin

    2014-01-01

    With the rapid development of society and the economy, an increasing number of human activities have gradually destroyed the marine environment. Marine environment monitoring is a vital problem and has increasingly attracted a great deal of research and development attention. During the past decade, various marine environment monitoring systems have been developed. The traditional marine environment monitoring system using an oceanographic research vessel is expensive and time-consuming and has a low resolution both in time and space. Wireless Sensor Networks (WSNs) have recently been considered as potentially promising alternatives for monitoring marine environments since they have a number of advantages such as unmanned operation, easy deployment, real-time monitoring, and relatively low cost. This paper provides a comprehensive review of the state-of-the-art technologies in the field of marine environment monitoring using wireless sensor networks. It first describes application areas, a common architecture of WSN-based oceanographic monitoring systems, a general architecture of an oceanographic sensor node, sensing parameters and sensors, and wireless communication technologies. Then, it presents a detailed review of some related projects, systems, techniques, approaches and algorithms. It also discusses challenges and opportunities in the research, development, and deployment of wireless sensor networks for marine environment monitoring. PMID:25215942

  9. Evolvable Block-Based Neural Network Design for Applications in Dynamic Environments

    Directory of Open Access Journals (Sweden)

    Saumil G. Merchant

    2010-01-01

    Full Text Available Dedicated hardware implementations of artificial neural networks promise to provide faster, lower-power operation when compared to software implementations executing on microprocessors, but rarely do these implementations have the flexibility to adapt and train online under dynamic conditions. A typical design process for artificial neural networks involves offline training using software simulations and synthesis and hardware implementation of the obtained network offline. This paper presents a design of block-based neural networks (BbNNs on FPGAs capable of dynamic adaptation and online training. Specifically the network structure and the internal parameters, the two pieces of the multiparametric evolution of the BbNNs, can be adapted intrinsically, in-field under the control of the training algorithm. This ability enables deployment of the platform in dynamic environments, thereby significantly expanding the range of target applications, deployment lifetimes, and system reliability. The potential and functionality of the platform are demonstrated using several case studies.

  10. Enhanced radar precipitation estimates using a combined clutter and beam blockage correction technique

    Directory of Open Access Journals (Sweden)

    A. Fornasiero

    2006-01-01

    Full Text Available Weather radar observations are currently the most reliable method for remote sensing of precipitation. However, a number of factors affect the quality of radar observations and may limit seriously automated quantitative applications of radar precipitation estimates such as those required in Numerical Weather Prediction (NWP data assimilation or in hydrological models. In this paper, a technique to correct two different problems typically present in radar data is presented and evaluated. The aspects dealt with are non-precipitating echoes – caused either by permanent ground clutter or by anomalous propagation of the radar beam (anaprop echoes – and also topographical beam blockage. The correction technique is based in the computation of realistic beam propagation trajectories based upon recent radiosonde observations instead of assuming standard radio propagation conditions. The correction consists of three different steps: 1 calculation of a Dynamic Elevation Map which provides the minimum clutter-free antenna elevation for each pixel within the radar coverage; 2 correction for residual anaprop, checking the vertical reflectivity gradients within the radar volume; and 3 topographical beam blockage estimation and correction using a geometric optics approach. The technique is evaluated with four case studies in the region of the Po Valley (N Italy using a C-band Doppler radar and a network of raingauges providing hourly precipitation measurements. The case studies cover different seasons, different radio propagation conditions and also stratiform and convective precipitation type events. After applying the proposed correction, a comparison of the radar precipitation estimates with raingauges indicates a general reduction in both the root mean squared error and the fractional error variance indicating the efficiency and robustness of the procedure. Moreover, the technique presented is not computationally expensive so it seems well suited to be

  11. Joint Efforts Towards European HF Radar Integration

    Science.gov (United States)

    Rubio, A.; Mader, J.; Griffa, A.; Mantovani, C.; Corgnati, L.; Novellino, A.; Schulz-Stellenfleth, J.; Quentin, C.; Wyatt, L.; Ruiz, M. I.; Lorente, P.; Hartnett, M.; Gorringe, P.

    2016-12-01

    During the past two years, significant steps have been made in Europe for achieving the needed accessibility to High Frequency Radar (HFR) data for a pan-European use. Since 2015, EuroGOOS Ocean Observing Task Teams (TT), such as HFR TT, are operational networks of observing platforms. The main goal is on the harmonization of systems requirements, systems design, data quality, improvement and proof of the readiness and standardization of HFR data access and tools. Particular attention is being paid by HFR TT to converge from different projects and programs toward those common objectives. First, JERICO-NEXT (Joint European Research Infrastructure network for Coastal Observatory - Novel European eXpertise for coastal observaTories, H2020 2015 Programme) will contribute on describing the status of the European network, on seeking harmonization through exchange of best practices and standardization, on developing and giving access to quality control procedures and new products, and finally on demonstrating the use of such technology in the general scientific strategy focused by the Coastal Observatory. Then, EMODnet (European Marine Observation and Data Network) Physics started to assemble HF radar metadata and data products within Europe in a uniform way. This long term program is providing a combined array of services and functionalities to users for obtaining free of charge data, meta-data and data products on the physical conditions of European sea basins and oceans. Additionally, the Copernicus Marine Environment Monitoring Service (CMEMS) delivers from 2015 a core information service to any user related to 4 areas of benefits: Maritime Safety, Coastal and Marine Environment, Marine Resources, and Weather, Seasonal Forecasting and Climate activities. INCREASE (Innovation and Networking for the integration of Coastal Radars into EuropeAn marine SErvices - CMEMS Service Evolution 2016) will set the necessary developments towards the integration of existing European

  12. Designing a parallel evolutionary algorithm for inferring gene networks on the cloud computing environment

    Science.gov (United States)

    2014-01-01

    Background To improve the tedious task of reconstructing gene networks through testing experimentally the possible interactions between genes, it becomes a trend to adopt the automated reverse engineering procedure instead. Some evolutionary algorithms have been suggested for deriving network parameters. However, to infer large networks by the evolutionary algorithm, it is necessary to address two important issues: premature convergence and high computational cost. To tackle the former problem and to enhance the performance of traditional evolutionary algorithms, it is advisable to use parallel model evolutionary algorithms. To overcome the latter and to speed up the computation, it is advocated to adopt the mechanism of cloud computing as a promising solution: most popular is the method of MapReduce programming model, a fault-tolerant framework to implement parallel algorithms for inferring large gene networks. Results This work presents a practical framework to infer large gene networks, by developing and parallelizing a hybrid GA-PSO optimization method. Our parallel method is extended to work with the Hadoop MapReduce programming model and is executed in different cloud computing environments. To evaluate the proposed approach, we use a well-known open-source software GeneNetWeaver to create several yeast S. cerevisiae sub-networks and use them to produce gene profiles. Experiments have been conducted and the results have been analyzed. They show that our parallel approach can be successfully used to infer networks with desired behaviors and the computation time can be largely reduced. Conclusions Parallel population-based algorithms can effectively determine network parameters and they perform better than the widely-used sequential algorithms in gene network inference. These parallel algorithms can be distributed to the cloud computing environment to speed up the computation. By coupling the parallel model population-based optimization method and the parallel

  13. APINetworks: A general API for the treatment of complex networks in arbitrary computational environments

    Science.gov (United States)

    Niño, Alfonso; Muñoz-Caro, Camelia; Reyes, Sebastián

    2015-11-01

    The last decade witnessed a great development of the structural and dynamic study of complex systems described as a network of elements. Therefore, systems can be described as a set of, possibly, heterogeneous entities or agents (the network nodes) interacting in, possibly, different ways (defining the network edges). In this context, it is of practical interest to model and handle not only static and homogeneous networks but also dynamic, heterogeneous ones. Depending on the size and type of the problem, these networks may require different computational approaches involving sequential, parallel or distributed systems with or without the use of disk-based data structures. In this work, we develop an Application Programming Interface (APINetworks) for the modeling and treatment of general networks in arbitrary computational environments. To minimize dependency between components, we decouple the network structure from its function using different packages for grouping sets of related tasks. The structural package, the one in charge of building and handling the network structure, is the core element of the system. In this work, we focus in this API structural component. We apply an object-oriented approach that makes use of inheritance and polymorphism. In this way, we can model static and dynamic networks with heterogeneous elements in the nodes and heterogeneous interactions in the edges. In addition, this approach permits a unified treatment of different computational environments. Tests performed on a C++11 version of the structural package show that, on current standard computers, the system can handle, in main memory, directed and undirected linear networks formed by tens of millions of nodes and edges. Our results compare favorably to those of existing tools.

  14. Environment Parameters Control Based on Wireless Sensor Network in Livestock Buildings

    OpenAIRE

    Zhang, Yu; Chen, Qiyu; Liu, Guanting; Shen, Weizheng; Wang, Guanlin

    2016-01-01

    The products quality and welfare of animals are closely related to the environment parameters in livestock buildings. A monitoring and control method of environment parameters in livestock buildings based on wireless sensor network is proposed in this paper. Temperature, humidity, light, carbon dioxide concentration, ammonia concentration, and hydrogen sulfide concentration can be monitored in real time by this method. The above six parameters will be adjusted and controlled through WLS algor...

  15. Client-Server and Peer-to-Peer Ad-hoc Network for a Flexible Learning Environment

    Directory of Open Access Journals (Sweden)

    Ferial Khaddage

    2011-01-01

    Full Text Available Peer-to-Peer (P2P networking in a mobile learning environment has become a popular topic of research. One of the new emerging research ideas is on the ability to combine P2P network with server-based network to form a strong efficient portable and compatible network infrastructure. This paper describes a unique mobile network architecture, which reflects the on-campus students’ need for a mobile learning environment. This can be achieved by combining two different networks, client-server and peer-to-peer ad-hoc to form a sold and secure network. This is accomplished by employing one peer within the ad-hoc network to act as an agent-peer to facilitate communication and information sharing between the two networks. It can be implemented without any major changes to the current network technologies, and can combine any wireless protocols such as GPRS, Wi-Fi, Bluetooth, and 3G.

  16. Comparison of atmospheric instability indices derived from radiosonde observations and precipitation values measured with a weather radar and a rain gauge network in Sao Paulo, Brazil.

    Science.gov (United States)

    Alves, Mauro; Martin, Inacio; Shkevov, Rumen; Gusev, Anatoly; De Abreu, Alessandro

    2016-07-01

    Radio soundings are carried out daily in more than 800 stations throughout the world. The data collected in the soundings are used in many meteorological applications such as numerical weather prediction and climate models. Despite the relatively large number of sounding stations, they are unevenly distributed over the globe. It is generally assumed that the desired distance between stations is 300 km. In this study, we performed a comparison of 20 soundings of two stations located 85 km apart (State of São Paulo, Brazil; 23.511811° S, 46.637528° W, and 23.212578° S, 45.866581° W) to determine whether there is a concordance between atmospheric instability indices derived from the data collected by soundings at the these different locations. Additionally, precipitation data obtained by a meteorological radar and a rain gauge network during the same period as the soundings are compared to the stability indices to establish a correlation between precipitation values and these indices.

  17. The Impacts of Network Centrality and Self-Regulation on an E-Learning Environment with the Support of Social Network Awareness

    Science.gov (United States)

    Lin, Jian-Wei; Huang, Hsieh-Hong; Chuang, Yuh-Shy

    2015-01-01

    An e-learning environment that supports social network awareness (SNA) is a highly effective means of increasing peer interaction and assisting student learning by raising awareness of social and learning contexts of peers. Network centrality profoundly impacts student learning in an SNA-related e-learning environment. Additionally,…

  18. Impact of Indoor Environment on Path Loss in Body Area Networks

    Science.gov (United States)

    Hausman, Sławomir; Januszkiewicz, Łukasz

    2014-01-01

    In this paper the influence of an example indoor environment on narrowband radio channel path loss for body area networks operating around 2.4 GHz is investigated using computer simulations and on-site measurements. In contrast to other similar studies, the simulation model included both a numerical human body phantom and its environment—room walls, floor and ceiling. As an example, radio signal attenuation between two different configurations of transceivers with dipole antennas placed in a direct vicinity of a human body (on-body scenario) is analyzed by computer simulations for several types of reflecting environments. In the analyzed case the propagation environments comprised a human body and office room walls. As a reference environment for comparison, free space with only a conducting ground plane, modelling a steel mesh reinforced concrete floor, was chosen. The transmitting and receiving antennas were placed in two on-body configurations chest–back and chest–arm. Path loss vs. frequency simulation results obtained using Finite Difference Time Domain (FDTD) method and a multi-tissue anthropomorphic phantom were compared to results of measurements taken with a vector network analyzer with a human subject located in an average-size empty cuboidal office room. A comparison of path loss values in different environments variants gives some qualitative and quantitative insight into the adequacy of simplified indoor environment model for the indoor body area network channel representation. PMID:25333289

  19. Impact of Indoor Environment on Path Loss in Body Area Networks

    Directory of Open Access Journals (Sweden)

    Sławomir Hausman

    2014-10-01

    Full Text Available In this paper the influence of an example indoor environment on narrowband radio channel path loss for body area networks operating around 2.4 GHz is investigated using computer simulations and on-site measurements. In contrast to other similar studies, the simulation model included both a numerical human body phantom and its environment—room walls, floor and ceiling. As an example, radio signal attenuation between two different configurations of transceivers with dipole antennas placed in a direct vicinity of a human body (on-body scenario is analyzed by computer simulations for several types of reflecting environments. In the analyzed case the propagation environments comprised a human body and office room walls. As a reference environment for comparison, free space with only a conducting ground plane, modelling a steel mesh reinforced concrete floor, was chosen. The transmitting and receiving antennas were placed in two on-body configurations chest–back and chest–arm. Path loss vs. frequency simulation results obtained using Finite Difference Time Domain (FDTD method and a multi-tissue anthropomorphic phantom were compared to results of measurements taken with a vector network analyzer with a human subject located in an average-size empty cuboidal office room. A comparison of path loss values in different environments variants gives some qualitative and quantitative insight into the adequacy of simplified indoor environment model for the indoor body area network channel representation.

  20. Lessons Learnt from and Sustainability of Adopting a Personal Learning Environment & Network (Ple&N)

    Science.gov (United States)

    Tsui, Eric; Sabetzadeh, Farzad

    2014-01-01

    This paper describes the feedback from the configuration and deployment of a Personal Learning Environment & Network (PLE&N) tool to support peer-based social learning for university students and graduates. An extension of an earlier project in which a generic and PLE&N was deployed for all learners, the current PLE&N is a…

  1. Adaptive management in agricultural innovation systems: The interactions between innovation networks and their environment

    NARCIS (Netherlands)

    Klerkx, L.W.A.; Aarts, M.N.C.; Leeuwis, C.

    2010-01-01

    The purpose of this article is to investigate effective reformism: strategies that innovation networks deploy to create changes in their environment in order to establish a more conducive context for the realization and durable embedding of their innovation projects. Using a case study approach,

  2. Adaptive management in agricultural innovation systems: the interactions between innovation networks and their environment

    NARCIS (Netherlands)

    Klerkx, L.; Aarts, N.; Leeuwis, C.

    2010-01-01

    The purpose of this article is to investigate effective reformism: strategies that innovation networks deploy to create changes in their environment in order to establish a more conducive context for the realization and durable embedding of their innovation projects. Using a case study approach,

  3. Simulation of emotions of agents in virtual environments using neural networks

    NARCIS (Netherlands)

    van Kesteren, A.-J.; van Kesteren, A.J.; op den Akker, Hendrikus J.A.; Poel, Mannes; Jokinen, K.; Heylen, Dirk K.J.; Nijholt, Antinus

    2000-01-01

    A distributed architecture for a system simulating the emotional state of an agent acting in a virtual environment is presented. The system is an implementation of an event appraisal model of emotional behaviour and uses neural networks to learn how the emotional state should be influenced by the

  4. Concept for trusted personal devices in a mobile and networked environment

    NARCIS (Netherlands)

    Bormann, Frank C.; Manteau, Laurent; Linke, Andreas; Pailles, Jean C.; van Dijk, Johannes A.G.M.

    2006-01-01

    In this article we present a concept for Trusted Personal Devices, which are intended to be the common platform for the next generation of Smart Cards and other secure devices in mobile and networked environments. The concept is based on a classification of technical profiles for different potential

  5. Between-Classroom Differences in Peer Network Features and Students' Perceptions of the Classroom Environment

    Science.gov (United States)

    Zadzora, Kathleen; Gest, Scott D.; Rodkin, Philip C.

    2011-01-01

    The objective of this poster is to examine whether differences in the structural features of classroom peer networks (tight-knittedness, hierarchy, salience norms) are associated with differences in how individual students perceive the classroom environment (relational support from teachers and peers) and express achievement-related beliefs…

  6. Gaining insight into business networks : A simulation based support environment to improve process orchestration

    NARCIS (Netherlands)

    Tewoldeberhan, T.W.

    2005-01-01

    In today's world, organizations are becoming increasingly interested in using business networks as a means to adapt to the ever-changing environment to increase their performance level. As a result, the focus of efforts to improve the performance of organizations has shifted from organizational

  7. Coded continuous wave meteor radar

    Science.gov (United States)

    Chau, J. L.; Vierinen, J.; Pfeffer, N.; Clahsen, M.; Stober, G.

    2016-12-01

    The concept of a coded continuous wave specular meteor radar (SMR) is described. The radar uses a continuously transmitted pseudorandom phase-modulated waveform, which has several advantages compared to conventional pulsed SMRs. The coding avoids range and Doppler aliasing, which are in some cases problematic with pulsed radars. Continuous transmissions maximize pulse compression gain, allowing operation at lower peak power than a pulsed system. With continuous coding, the temporal and spectral resolution are not dependent on the transmit waveform and they can be fairly flexibly changed after performing a measurement. The low signal-to-noise ratio before pulse compression, combined with independent pseudorandom transmit waveforms, allows multiple geographically separated transmitters to be used in the same frequency band simultaneously without significantly interfering with each other. Because the same frequency band can be used by multiple transmitters, the same interferometric receiver antennas can be used to receive multiple transmitters at the same time. The principles of the signal processing are discussed, in addition to discussion of several practical ways to increase computation speed, and how to optimally detect meteor echoes. Measurements from a campaign performed with a coded continuous wave SMR are shown and compared with two standard pulsed SMR measurements. The type of meteor radar described in this paper would be suited for use in a large-scale multi-static network of meteor radar transmitters and receivers. Such a system would be useful for increasing the number of meteor detections to obtain improved meteor radar data products, such as wind fields. This type of a radar would also be useful for over-the-horizon radar, ionosondes, and observations of field-aligned-irregularities.

  8. The dynamic wave expansion neural network model for robot motion planning in time-varying environments.

    Science.gov (United States)

    Lebedev, Dmitry V; Steil, Jochen J; Ritter, Helge J

    2005-04-01

    We introduce a new type of neural network--the dynamic wave expansion neural network (DWENN)--for path generation in a dynamic environment for both mobile robots and robotic manipulators. Our model is parameter-free, computationally efficient, and its complexity does not explicitly depend on the dimensionality of the configuration space. We give a review of existing neural networks for trajectory generation in a time-varying domain, which are compared to the presented model. We demonstrate several representative simulative comparisons as well as the results of long-run comparisons in a number of randomly-generated scenes, which reveal that the proposed model yields dominantly shorter paths, especially in highly-dynamic environments.

  9. Lightweight Context Aware Routing in Wireless Sensor Networks for Real Environments

    Directory of Open Access Journals (Sweden)

    Samia Aijaz

    2015-07-01

    Full Text Available Design and implementation of a WSN (Wireless Sensor Network that can efficiently work for a longer time period must include identification of the deployment environment context and to conform to the behavior of the sensor nodes. The context information when treated with evaluation factor becomes a process of context awareness and the evaluation factor is called the context attribute. In this paper, we consider the context factor of energy. The paper identifies analyses and evaluates efficiency of two when used in a context aware environment. Furthermore, the study also highlights the strengths and weaknesses of sensor SPIN (Sensor Protocol for Information via Negotiation and LEACH (Low Energy Adaptive Clustering Hierarchy protocols with respect to the support for WSN with heavy network traffic conditions. The performance has been evaluated in terms of energy efficiency, data packet transmission, network status, data management, reliability, etc.

  10. How Urban Youth Perceive Relationships Among School Environments, Social Networks, Self-Concept, and Substance Use.

    Science.gov (United States)

    Dudovitz, Rebecca N; Perez-Aguilar, Giselle; Kim, Grace; Wong, Mitchell D; Chung, Paul J

    2017-03-01

    Studies suggest adolescent substance use aligns with academic and behavioral self-concept (whether teens think of themselves as good or bad students and as rule followers or rule breakers) as well as peer and adult social networks. Schools are an important context in which self-concept and social networks develop, but it remains unclear how school environments might be leveraged to promote healthy development and prevent substance use. We sought to describe how youth perceive the relationships among school environments, adolescent self-concept, social networks, and substance use. Semistructured interviews with 32 low-income minority youth (aged 17-22 years) who participated in a prior study, explored self-concept development, school environments, social networks, and substance use decisions. Recruitment was stratified by whether, during high school, they had healthy or unhealthy self-concept profiles and had engaged in or abstained from substance use. Youth described feeling labeled by peers and teachers and how these labels became incorporated into their self-concept. Teachers who made students feel noticed (eg, by learning students' names) and had high academic expectations reinforced healthy self-concepts. Academic tracking, extracurricular activities, and school norms determined potential friendship networks, grouping students either with well-behaving or misbehaving peers. Youth described peer groups, combined with their self-concept, shaping their substance use decisions. Affirming healthy aspects of their self-concept at key risk behavior decision points helped youth avoid substance use in the face of peer pressure. Youth narratives suggest school environments shape adolescent self-concept and adult and peer social networks, all of which impact substance use. Copyright © 2016 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

  11. RADAR PPI Scope Overlay

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — RADAR PPI Scope Overlays are used to position a RADAR image over a station at the correct resolution. The archive maintains several different RADAR resolution types,...

  12. LPI Radar Waveform Recognition Based on Time-Frequency Distribution

    Directory of Open Access Journals (Sweden)

    Ming Zhang

    2016-10-01

    Full Text Available In this paper, an automatic radar waveform recognition system in a high noise environment is proposed. Signal waveform recognition techniques are widely applied in the field of cognitive radio, spectrum management and radar applications, etc. We devise a system to classify the modulating signals widely used in low probability of intercept (LPI radar detection systems. The radar signals are divided into eight types of classifications, including linear frequency modulation (LFM, BPSK (Barker code modulation, Costas codes and polyphase codes (comprising Frank, P1, P2, P3 and P4. The classifier is Elman neural network (ENN, and it is a supervised classification based on features extracted from the system. Through the techniques of image filtering, image opening operation, skeleton extraction, principal component analysis (PCA, image binarization algorithm and Pseudo–Zernike moments, etc., the features are extracted from the Choi–Williams time-frequency distribution (CWD image of the received data. In order to reduce the redundant features and simplify calculation, the features selection algorithm based on mutual information between classes and features vectors are applied. The superiority of the proposed classification system is demonstrated by the simulations and analysis. Simulation results show that the overall ratio of successful recognition (RSR is 94.7% at signal-to-noise ratio (SNR of −2 dB.

  13. A Wearable Wireless Sensor Network for Indoor Smart Environment Monitoring in Safety Applications

    Directory of Open Access Journals (Sweden)

    Diego Antolín

    2017-02-01

    Full Text Available This paper presents the implementation of a wearable wireless sensor network aimed at monitoring harmful gases in industrial environments. The proposed solution is based on a customized wearable sensor node using a low-power low-rate wireless personal area network (LR-WPAN communications protocol, which as a first approach measures CO2 concentration, and employs different low power strategies for appropriate energy handling which is essential to achieving long battery life. These wearables nodes are connected to a deployed static network and a web-based application allows data storage, remote control and monitoring of the complete network. Therefore, a complete and versatile remote web application with a locally implemented decision-making system is accomplished, which allows early detection of hazardous situations for exposed workers.

  14. A Wearable Wireless Sensor Network for Indoor Smart Environment Monitoring in Safety Applications.

    Science.gov (United States)

    Antolín, Diego; Medrano, Nicolás; Calvo, Belén; Pérez, Francisco

    2017-02-14

    This paper presents the implementation of a wearable wireless sensor network aimed at monitoring harmful gases in industrial environments. The proposed solution is based on a customized wearable sensor node using a low-power low-rate wireless personal area network (LR-WPAN) communications protocol, which as a first approach measures CO₂ concentration, and employs different low power strategies for appropriate energy handling which is essential to achieving long battery life. These wearables nodes are connected to a deployed static network and a web-based application allows data storage, remote control and monitoring of the complete network. Therefore, a complete and versatile remote web application with a locally implemented decision-making system is accomplished, which allows early detection of hazardous situations for exposed workers.

  15. Glycosylation Network Analysis Toolbox: a MATLAB-based environment for systems glycobiology

    Science.gov (United States)

    Liu, Gang; Neelamegham, Sriram

    2013-01-01

    Summary: Systems glycobiology studies the interaction of various pathways that regulate glycan biosynthesis and function. Software tools for the construction and analysis of such pathways are not yet available. We present GNAT, a platform-independent, user-extensible MATLAB-based toolbox that provides an integrated computational environment to construct, manipulate and simulate glycans and their networks. It enables integration of XML-based glycan structure data into SBML (Systems Biology Markup Language) files that describe glycosylation reaction networks. Curation and manipulation of networks is facilitated using class definitions and glycomics database query tools. High quality visualization of networks and their steady-state and dynamic simulation are also supported. Availability: The software package including source code, help documentation and demonstrations are available at http://sourceforge.net/projects/gnatmatlab/files/. Contact: neel@buffalo.edu or gangliu@buffalo.edu PMID:23230149

  16. 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

    is initially demonstrated in a 52 DECT base station installation covering four office buildings of total 4500 m2 . Finally the paper proposes the application of a commercial off-the-shelf wireless broadband network as a sensor network, without any additional hardware, for physical intrusion detection of e...... on the network. Then the extension of a DECT network into determining the location of DECT terminals, aiming at the design of a location based system is described. The location method is based on the received signal strength measurements in the DECT clients communication with the base stations. The localization.......g. an indoor site. It is demonstrated how it can be used for detecting door opening and person passing, in an environment of 243 m2 with three rooms and a corridor, using three low cost access points....

  17. Monitoring the Environment in a Lava Tube with a Wireless Sensor Network

    Science.gov (United States)

    Li, Y.; Jorgensen, A. M.; Wilson, J. L.; Rendon, N. M.

    2010-12-01

    Monitoring cave environments is important for several reasons. For instance, through the studies of cave environments, we can better protect cave ecology. Past experiments have monitored cave environments, although most of those were based on individual sensor nodes such as data loggers. In this paper we introduce and discuss a ZigBee wireless sensor network-based platform used for cave environment monitoring. The platform is based on a Freescale ZigBee evaluation kit. We carried out a proof-of-concept experiment in Junction Cave, a lava tube, at El Malpais National Monument in New Mexico. That experiment monitored temperature, humidity, and air turbulence inside the cave. The instrumentation consisted of a turbulence tower with five thermocouple-based sensors, reaching from the floor to the ceiling of the cave, temperature/humidity sensors distributed throughout the cave, and a low-power embedded Linux computer for data collection and storage. The experiment measured interesting air turbulence variations at different heights, which we related to to weather changes outside the cave and human activities inside the cave. The experiment also observed variations of air temperature at different locations inside the cave. In this presentation we will discuss the instrumentation as well as interpretations of the observations. The experiment demonstrated that a ZigBee wireless sensor network-based monitoring system is a potentially feasible platform for a cave environment monitoring system. We also found that network reliability, node cost, and power consumption need to be improved for future systems.

  18. Advances in bistatic radar

    CERN Document Server

    Willis, Nick

    2007-01-01

    Advances in Bistatic Radar updates and extends bistatic and multistatic radar developments since publication of Willis' Bistatic Radar in 1991. New and recently declassified military applications are documented. Civil applications are detailed including commercial and scientific systems. Leading radar engineers provide expertise to each of these applications. Advances in Bistatic Radar consists of two major sections: Bistatic/Multistatic Radar Systems and Bistatic Clutter and Signal Processing. Starting with a history update, the first section documents the early and now declassified military

  19. Network Environments and Well-Being: An Examination of Personal Network Structure, Social Capital, and Perceived Social Support.

    Science.gov (United States)

    Lee, Seungyoon; Chung, Jae Eun; Park, Namkee

    2018-01-01

    Previous studies have demonstrated the role of social networks, social capital, and social support in individuals' well-being. However, the ways in which these related constructs simultaneously influence one's well-being outcomes and relate to one another have not been closely examined. This study pays particular attention to the structural characteristics of personal networks, distinction between offline and online social capital, and different indicators of well-being outcomes. Based on survey data collected from 574 college students, the study found that two dimensions of personal networks-density and gender homophily-and social capital in the form of offline bonding capital explained perceived social support. Further, perceived social support consistently predicted well-being outcomes and played a mediating role between personal network density and well-being, as well as between offline bonding capital and well-being. The results offer implications for a more nuanced understanding of the role of individuals' interpersonal and social environments in well-being outcomes.

  20. Eastern Sahara Geology from Orbital Radar: Potential Analog to Mars

    Science.gov (United States)

    Farr, T. G.; Paillou, P.; Heggy, E.

    2004-01-01

    Much of the surface of Mars has been intensely reworked by aeolian processes and key evidence about the history of the Martian environment seems to be hidden beneath a widespread layer of debris (paleo lakes and rivers, faults, impact craters). In the same way, the recent geological and hydrological history of the eastern Sahara is still mainly hidden under large regions of wind-blown sand which represent a possible terrestrial analog to Mars. The subsurface geology there is generally invisible to optical remote sensing techniques, but radar images obtained from the Shuttle Imaging Radar (SIR) missions were able to penetrate the superficial sand layer to reveal parts of paleohydrological networks in southern Egypt.

  1. Radar Sounder

    Science.gov (United States)

    1988-09-01

    free" measurements on the same or previous orbits. The Scatterometer is an integral part of the radar. The proposed system which is currently called...Right Arrays SATELLITE ( I ATOMOS PHERE/ SWATHWI DTH Figure 3.1.1 Metrad Coverage 18 4 05. 4 1-4 " -u a . .4 c4 641 C Ov31 N -4 a ~ U . - I.44m 41 44...application is not a study objective, but could be considered as part of an experimental program utilizing scatterometer, radiometer and high resolution

  2. Information Sharing Mechanism among Mobile Agents In Ad-hoc Network Environment and Its Applications

    Directory of Open Access Journals (Sweden)

    Kunio Umetsuji

    2004-12-01

    Full Text Available Mobile agents are programs that can move from one site to another in a network with their data and states. Mobile agents are expected to be an essential tool in pervasive computing. In multi platform environment, it is important to communicate with mobile agents only using their universal or logical name not using their physical locations. More, in an ad-hoc network environment, an agent can migrate autonomously and communicate with other agents on demand. It is difficult that mobile agent grasps the position information on other agents correctly each other, because mobile agent processes a task while moving a network successively. In order to realize on-demand mutual communication among mobile agents without any centralized servers, we propose a new information sharing mechanism within mobile agents. In this paper, we present a new information sharing mechanism within mobile agents. The method is a complete peer based and requires no agent servers to manage mobile agent locations. Therefore, a mobile agent can get another mobile agent, communicate with it and shares information stored in the agent without any knowledge of the location of the target mobile agent. The basic idea of the mechanism is an introduction of Agent Ring, Agent Chain and Shadow Agent. With this mechanism, each agent can communicate with other agents in a server-less environment, which is suitable for ad-hoc agent network and an agent system can manage agents search and communications efficiently.

  3. Adolescents' social environment and depression: social networks, extracurricular activity, and family relationship influences.

    Science.gov (United States)

    Mason, Michael J; Schmidt, Christopher; Abraham, Anisha; Walker, Leslie; Tercyak, Kenneth

    2009-12-01

    The present study examined components of adolescents' social environment (social network, extracurricular activities, and family relationships) in association with depression. A total of 332 adolescents presenting for a routine medical check-up were self-assessed for social network risk (i.e., smoking habits of best male and female friends), extracurricular activity level (i.e., participation in organized sports teams, clubs, etc.), family relationship quality (i.e., cohesion and conflict), and symptoms of depression (i.e., minimal, mild, moderate/severe). Results of a forward linear regression modeling indicate that social environment components were associated with a significant proportion of the variance in adolescent depression (Adjusted R (2) = .177, p social network (beta = .107, p social environment plays in adolescent depression, as well as yields new insights into socially-based intervention targets that may ameliorate adolescent depression. These intervention targets may be gender-specific, include positive social network skills training, increase adolescents' engagement in organized activities, and attend to the quality of their family relationships.

  4. An Analysis of Density and Degree-Centrality According to the Social Networking Structure Formed in an Online Learning Environment

    Science.gov (United States)

    Ergün, Esin; Usluel, Yasemin Koçak

    2016-01-01

    In this study, we assessed the communication structure in an educational online learning environment using social network analysis (SNA). The communication structure was examined with respect to time, and instructor's participation. The course was implemented using ELGG, a network learning environment, blended with face-to-face sessions over a…

  5. Students' Personal Networks in Virtual and Personal Learning Environments: A Case Study in Higher Education Using Learning Analytics Approach

    Science.gov (United States)

    Casquero, Oskar; Ovelar, Ramón; Romo, Jesús; Benito, Manuel; Alberdi, Mikel

    2016-01-01

    The main objective of this paper is to analyse the effect of the affordances of a virtual learning environment and a personal learning environment (PLE) in the configuration of the students' personal networks in a higher education context. The results are discussed in light of the adaptation of the students to the learning network made up by two…

  6. SMAP RADAR Calibration and Validation

    Science.gov (United States)

    West, R. D.; Jaruwatanadilok, S.; Chaubel, M. J.; Spencer, M.; Chan, S. F.; Chen, C. W.; Fore, A.

    2015-12-01

    The Soil Moisture Active Passive (SMAP) mission launched on Jan 31, 2015. The mission employs L-band radar and radiometer measurements to estimate soil moisture with 4% volumetric accuracy at a resolution of 10 km, and freeze-thaw state at a resolution of 1-3 km. Immediately following launch, there was a three month instrument checkout period, followed by six months of level 1 (L1) calibration and validation. In this presentation, we will discuss the calibration and validation activities and results for the L1 radar data. Early SMAP radar data were used to check commanded timing parameters, and to work out issues in the low- and high-resolution radar processors. From April 3-13 the radar collected receive only mode data to conduct a survey of RFI sources. Analysis of the RFI environment led to a preferred operating frequency. The RFI survey data were also used to validate noise subtraction and scaling operations in the radar processors. Normal radar operations resumed on April 13. All radar data were examined closely for image quality and calibration issues which led to improvements in the radar data products for the beta release at the end of July. Radar data were used to determine and correct for small biases in the reported spacecraft attitude. Geo-location was validated against coastline positions and the known positions of corner reflectors. Residual errors at the time of the beta release are about 350 m. Intra-swath biases in the high-resolution backscatter images are reduced to less than 0.3 dB for all polarizations. Radiometric cross-calibration with Aquarius was performed using areas of the Amazon rain forest. Cross-calibration was also examined using ocean data from the low-resolution processor and comparing with the Aquarius wind model function. Using all a-priori calibration constants provided good results with co-polarized measurements matching to better than 1 dB, and cross-polarized measurements matching to about 1 dB in the beta release. During the

  7. The Shared Mobile Atmospheric Research and Teaching Radar: A Collaboration to Enhance Research and Teaching.

    Science.gov (United States)

    Biggerstaff, Michael I.; Wicker, Louis J.; Guynes, Jerry; Ziegler, Conrad; Straka, Jerry M.; Rasmussen, Erik N.; Doggett, Arthur, IV; Carey, Larry D.; Schroeder, John L.; Weiss, Chris

    2005-09-01

    A group of scientists from three universities across two different states and from one federal research laboratory joined together to build and deploy two mobile C-band Doppler weather radars to enhance research and promote meteorological education. This 5-yr project led to the development of the Shared Mobile Atmospheric Research and Teaching (SMART) radar coalition that built the first mobile C-band Doppler weather radar in the United States and also successfully deployed the first mobile C-band dual-Doppler network in a landfalling hurricane. This accomplishment marked the beginning of an era in which high temporal and spatial resolution precipitation and dual-Doppler wind data over mesoscale (100 km) regions can be acquired from mobile ground-based platforms during extreme heavy rain and high-wind events.In this paper, we discuss the rationale for building the mobile observing systems, highlight some of the challenges that were encountered in creating a unique multia-gency coalition, provide examples of how the SMART radars have contributed to research and education, and discuss future plans for continued development and management of the radar facility, including how others may use the radars for their own research and teaching programs.The capability of the SMART radars to measure winds in non-precipitating environments, to capture rapidly evolving, short-lived, small-scale tornadic circulations, and to sample mesoscale regions with high spatial resolution over broad regions of heavy rainfall is demonstrated. Repeated successful intercepts provide evidence that these radars are capable of being used to study a wide range of atmospheric phenomena.

  8. Shuttle Imaging Radar-C mission operations - Technology test bed for Earth Observing System synthetic aperture radar

    Science.gov (United States)

    Trimble, J. P.; Collins, C. E.

    1992-01-01

    The mission operations for the Space Radar Lab (SRL), particularly in the areas of real-time replanning and science activity coordination, are presented. The two main components of SRL are the Shuttle Imaging Radar-C and the X-Band Synthetic Aperture Radar. The Earth Observing System SAR will be a multispectral, multipolarization radar satellite that will provide information over an entire decade, permitting scientists to monitor large-scale changes in the earth's environment over a long period of time.

  9. Sensor and Communication Network Technology for Harsh Environments in the Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Jai Wan; Choi, Young Soo; Lee, Jae Chul; Choi, Yu Rak; Jung, Gwang Il; Jung, Jong Eun; Park, Hee Yoon; Hong, Seok Bong; Koo, In Soo

    2008-02-15

    One of the challenges in harsh environments qualification and verification for emerging new I and C system of the nuclear power plant is to define the operational environment of these new emerging I and C sensor and communication network such that they are tested to the limits of a mission without requiring expensive over design. To aid this, this report defines, discusses and recommends environmental guideline and verification requirements for using state-of-the-art RPS sensors, fiber optic communication system, wireless communication and wireless smart sensors in nuclear harsh environments. This report focuses on advances in sensors (e.g., temperature, pressure, neutron and thermal power sensors) and their potential impact. Discussed are: radiation, thermal, electromagnetic, and electrical environment specifications. Presented are the typical performance data (survivability guidelines and experimental data), evaluation procedure and standard test method of communication devices, state-of-the-art RPS sensors, and communication systems.

  10. Identifying structural damage with ground penetrating radar

    CSIR Research Space (South Africa)

    Van Schoor, Abraham M

    2008-07-01

    Full Text Available Ground penetrating radar (GPR) and electrical resistance tomography (ERT) surveys were conducted in an urban environment in an attempt to identify the cause of severe structural damage to a historically significant residential property...

  11. Space Compatible Radar Absorbing Materials Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase 1 project shall investigate novel radar absorbing materials (RAM) for use in space or simulated space environments. These materials are lightweight...

  12. Estimation of corn yield using multi-temporal optical and radar satellite data and artificial neural networks

    Science.gov (United States)

    Fieuzal, R.; Marais Sicre, C.; Baup, F.

    2017-05-01

    The yield forecasting of corn constitutes a key issue in agricultural management, particularly in the context of demographic pressure and climate change. This study presents two methods to estimate yields using artificial neural networks: a diagnostic approach based on all the satellite data acquired throughout the agricultural season, and a real-time approach, where estimates are updated after each image was acquired in the microwave and optical domains (Formosat-2, Spot-4/5, TerraSAR-X, and Radarsat-2) throughout the crop cycle. The results are based on the Multispectral Crop Monitoring experimental campaign conducted by the CESBIO (Centre d'Études de la BIOsphère) laboratory in 2010 over an agricultural region in southwestern France. Among the tested sensor configurations (multi-frequency, multi-polarization or multi-source data), the best yield estimation performance (using the diagnostic approach) is obtained with reflectance acquired in the red wavelength region, with a coefficient of determination of 0.77 and an RMSE of 6.6 q ha-1. In the real-time approach the combination of red reflectance and CHH backscattering coefficients provides the best compromise between the accuracy and earliness of the yield estimate (more than 3 months before the harvest), with an R2 of 0.69 and an RMSE of 7.0 q ha-1 during the development of the central stem. The two best yield estimates are similar in most cases (for more than 80% of the monitored fields), and the differences are related to discrepancies in the crop growth cycle and/or the consequences of pests.

  13. A long-term environmental sensor network in a glacial environment: challenges and results

    Science.gov (United States)

    Martinez, K.; Hart, J. K.; Basford, P. J.; Gong, X.; Edwards, L.; Pethica, C.; Glacsweb Team

    2011-12-01

    We report the findings from wireless environmental sensor network installed at Skalafellsjökull, Iceland, which has now been deployed for three years. The scientific aim of the project was to use a sensor network to better understand subglacial processes in order to investigate the response of glaciers to climate change. The engineering aim was to produce a working environmental sensor network which could operate in a very challenging environment. The sensor network comprised: 1. Wireless subglacial probes which monitored the subglacial environment for 2 years. They were able to show the nature of the subglacial environment, in particular the occurrence of stick-slip motion. 2. Base Station on the glacier surface, collecting probe data, as well as GPS and weather data for 3 years. 3. Reference Station close to the glacier, collecting GPS and weather data for 2 years 4. Automatic web-data harvesting of weather, GPS recordings and web cams. A combination of this data allowed us to interpret glacier dynamics over the period, while evaluating the performance of the sensor network under extreme conditions. This paper will report on the most recent deployments which include; long range WiFi alongside GPRS backup for communications off-site, Python scripting of base station power-sensitive behaviour, adaptive sampling based on energy availability and trials of the Contiki operating system in the new custom wireless sensor nodes. Additional data streams have also been established by equipping the base station with geophones and putting a full weather station at the reference station. Further enhancements that have been made include moving further into the glacier in order to experience faster flows.

  14. The Comparative Study of Grey Literature Orgnization at Home and Abroad in Network Environment

    OpenAIRE

    Xu, Liu Jing

    2005-01-01

    Grey literature is an important information resource , and Internet makes it easier to organize them. This paper introduces how the System for Information on Grey Literature in Europe(SIGLE) and GreyNet organize the grey literature. And then it presents how to organize grey literature in China in network environment. Finally, by contrast a conclusion is drawn that there are several disadvantages in the grey literature organization in China.

  15. Design and simulation of sensor networks for tracking Wifi users in outdoor urban environments

    Science.gov (United States)

    Thron, Christopher; Tran, Khoi; Smith, Douglas; Benincasa, Daniel

    2017-05-01

    We present a proof-of-concept investigation into the use of sensor networks for tracking of WiFi users in outdoor urban environments. Sensors are fixed, and are capable of measuring signal power from users' WiFi devices. We derive a maximum likelihood estimate for user location based on instantaneous sensor power measurements. The algorithm takes into account the effects of power control, and is self-calibrating in that the signal power model used by the location algorithm is adjusted and improved as part of the operation of the network. Simulation results to verify the system's performance are presented. The simulation scenario is based on a 1.5 km2 area of lower Manhattan, The self-calibration mechanism was verified for initial rms (root mean square) errors of up to 12 dB in the channel power estimates: rms errors were reduced by over 60% in 300 track-hours, in systems with limited power control. Under typical operating conditions with (without) power control, location rms errors are about 8.5 (5) meters with 90% accuracy within 9 (13) meters, for both pedestrian and vehicular users. The distance error distributions for smaller distances (issue of optimal sensor placement in the sensor network is also addressed. We specify a linear programming algorithm for determining sensor placement for networks with reduced number of sensors. In our test case, the algorithm produces a network with 18.5% fewer sensors with comparable accuracy estimation performance. Finally, we discuss future research directions for improving the accuracy and capabilities of sensor network systems in urban environments.

  16. Virtual Environments for Visualizing Structural Health Monitoring Sensor Networks, Data, and Metadata.

    Science.gov (United States)

    Napolitano, Rebecca; Blyth, Anna; Glisic, Branko

    2018-01-16

    Visualization of sensor networks, data, and metadata is becoming one of the most pivotal aspects of the structural health monitoring (SHM) process. Without the ability to communicate efficiently and effectively between disparate groups working on a project, an SHM system can be underused, misunderstood, or even abandoned. For this reason, this work seeks to evaluate visualization techniques in the field, identify flaws in current practices, and devise a new method for visualizing and accessing SHM data and metadata in 3D. More precisely, the work presented here reflects a method and digital workflow for integrating SHM sensor networks, data, and metadata into a virtual reality environment by combining spherical imaging and informational modeling. Both intuitive and interactive, this method fosters communication on a project enabling diverse practitioners of SHM to efficiently consult and use the sensor networks, data, and metadata. The method is presented through its implementation on a case study, Streicker Bridge at Princeton University campus. To illustrate the efficiency of the new method, the time and data file size were compared to other potential methods used for visualizing and accessing SHM sensor networks, data, and metadata in 3D. Additionally, feedback from civil engineering students familiar with SHM is used for validation. Recommendations on how different groups working together on an SHM project can create SHM virtual environment and convey data to proper audiences, are also included.

  17. A Dynamic Intrusion Detection System Based on Multivariate Hotelling's T2 Statistics Approach for Network Environments.

    Science.gov (United States)

    Sivasamy, Aneetha Avalappampatty; Sundan, Bose

    2015-01-01

    The ever expanding communication requirements in today's world demand extensive and efficient network systems with equally efficient and reliable security features integrated for safe, confident, and secured communication and data transfer. Providing effective security protocols for any network environment, therefore, assumes paramount importance. Attempts are made continuously for designing more efficient and dynamic network intrusion detection models. In this work, an approach based on Hotelling's T(2) method, a multivariate statistical analysis technique, has been employed for intrusion detection, especially in network environments. Components such as preprocessing, multivariate statistical analysis, and attack detection have been incorporated in developing the multivariate Hotelling's T(2) statistical model and necessary profiles have been generated based on the T-square distance metrics. With a threshold range obtained using the central limit theorem, observed traffic profiles have been classified either as normal or attack types. Performance of the model, as evaluated through validation and testing using KDD Cup'99 dataset, has shown very high detection rates for all classes with low false alarm rates. Accuracy of the model presented in this work, in comparison with the existing models, has been found to be much better.

  18. Motion planning for autonomous vehicle based on radial basis function neural network in unstructured environment.

    Science.gov (United States)

    Chen, Jiajia; Zhao, Pan; Liang, Huawei; Mei, Tao

    2014-09-18

    The autonomous vehicle is an automated system equipped with features like environment perception, decision-making, motion planning, and control and execution technology. Navigating in an unstructured and complex environment is a huge challenge for autonomous vehicles, due to the irregular shape of road, the requirement of real-time planning, and the nonholonomic constraints of vehicle. This paper presents a motion planning method, based on the Radial Basis Function (RBF) neural network, to guide the autonomous vehicle in unstructured environments. The proposed algorithm extracts the drivable region from the perception grid map based on the global path, which is available in the road network. The sample points are randomly selected in the drivable region, and a gradient descent method is used to train the RBF network. The parameters of the motion-planning algorithm are verified through the simulation and experiment. It is observed that the proposed approach produces a flexible, smooth, and safe path that can fit any road shape. The method is implemented on autonomous vehicle and verified against many outdoor scenes; furthermore, a comparison of proposed method with the existing well-known Rapidly-exploring Random Tree (RRT) method is presented. The experimental results show that the proposed method is highly effective in planning the vehicle path and offers better motion quality.

  19. A laser radar experiment

    Science.gov (United States)

    Stiglitz, Martin R.; Blanchard, Christine

    1990-09-01

    An experiment demonstrating the feasibility of using a laser radar for long-range target acquisition and tracking is discussed. A CO2 laser was used to collect range Doppler images, while a medium-power argon ion laser was employed for angular tracking. Laser-radar operation is outlined with emphasis on isotopic laser radars. Laser-radar imaging is covered, and a laser-radar range equation is given. Experimental laser-radar transmitter, receiver, and telescope are described. A 35-foot long surface-to-air missile and payload were tracked in the experiment, with the laser radar acquiring the targets as they reached 480 km in altitude, 750 km from the radar site. The 4-ft-diameter aperture laser-radar telescope provided the resolution and range accuracy equivalent to that of a 120-ft microwave radar antenna.

  20. Study on an agricultural environment monitoring server system using Wireless Sensor Networks.

    Science.gov (United States)

    Hwang, Jeonghwan; Shin, Changsun; Yoe, Hyun

    2010-01-01

    This paper proposes an agricultural environment monitoring server system for monitoring information concerning an outdoors agricultural production environment utilizing Wireless Sensor Network (WSN) technology. The proposed agricultural environment monitoring server system collects environmental and soil information on the outdoors through WSN-based environmental and soil sensors, collects image information through CCTVs, and collects location information using GPS modules. This collected information is converted into a database through the agricultural environment monitoring server consisting of a sensor manager, which manages information collected from the WSN sensors, an image information manager, which manages image information collected from CCTVs, and a GPS manager, which processes location information of the agricultural environment monitoring server system, and provides it to producers. In addition, a solar cell-based power supply is implemented for the server system so that it could be used in agricultural environments with insufficient power infrastructure. This agricultural environment monitoring server system could even monitor the environmental information on the outdoors remotely, and it could be expected that the use of such a system could contribute to increasing crop yields and improving quality in the agricultural field by supporting the decision making of crop producers through analysis of the collected information.

  1. Sign: large-scale gene network estimation environment for high performance computing.

    Science.gov (United States)

    Tamada, Yoshinori; Shimamura, Teppei; Yamaguchi, Rui; Imoto, Seiya; Nagasaki, Masao; Miyano, Satoru

    2011-01-01

    Our research group is currently developing software for estimating large-scale gene networks from gene expression data. The software, called SiGN, is specifically designed for the Japanese flagship supercomputer "K computer" which is planned to achieve 10 petaflops in 2012, and other high performance computing environments including Human Genome Center (HGC) supercomputer system. SiGN is a collection of gene network estimation software with three different sub-programs: SiGN-BN, SiGN-SSM and SiGN-L1. In these three programs, five different models are available: static and dynamic nonparametric Bayesian networks, state space models, graphical Gaussian models, and vector autoregressive models. All these models require a huge amount of computational resources for estimating large-scale gene networks and therefore are designed to be able to exploit the speed of 10 petaflops. The software will be available freely for "K computer" and HGC supercomputer system users. The estimated networks can be viewed and analyzed by Cell Illustrator Online and SBiP (Systems Biology integrative Pipeline). The software project web site is available at http://sign.hgc.jp/ .

  2. Computational design of genomic transcriptional networks with adaptation to varying environments

    Science.gov (United States)

    Carrera, Javier; Elena, Santiago F.; Jaramillo, Alfonso

    2012-01-01

    Transcriptional profiling has been widely used as a tool for unveiling the coregulations of genes in response to genetic and environmental perturbations. These coregulations have been used, in a few instances, to infer global transcriptional regulatory models. Here, using the large amount of transcriptomic information available for the bacterium Escherichia coli, we seek to understand the design principles determining the regulation of its transcriptome. Combining transcriptomic and signaling data, we develop an evolutionary computational procedure that allows obtaining alternative genomic transcriptional regulatory network (GTRN) that still maintains its adaptability to dynamic environments. We apply our methodology to an E. coli GTRN and show that it could be rewired to simpler transcriptional regulatory structures. These rewired GTRNs still maintain the global physiological response to fluctuating environments. Rewired GTRNs contain 73% fewer regulated operons. Genes with similar functions and coordinated patterns of expression across environments are clustered into longer regulated operons. These synthetic GTRNs are more sensitive and show a more robust response to challenging environments. This result illustrates that the natural configuration of E. coli GTRN does not necessarily result from selection for robustness to environmental perturbations, but that evolutionary contingencies may have been important as well. We also discuss the limitations of our methodology in the context of the demand theory. Our procedure will be useful as a novel way to analyze global transcription regulation networks and in synthetic biology for the de novo design of genomes. PMID:22927389

  3. Air-Sense: indoor environment monitoring evaluation system based on ZigBee network

    Science.gov (United States)

    Huang, Yang; Hu, Liang; Yang, Disheng; Liu, Hengchang

    2017-08-01

    In the modern life, people spend most of their time indoors. However, indoor environmental quality problems have always been affecting people’s social activities. In general, indoor environmental quality is also related to our indoor activities. Since most of the organic irritants and volatile gases are colorless, odorless and too tiny to be seen, because we have been unconsciously overlooked indoor environment quality. Consequently, our body suffer a great health problem. In this work, we propose Air-Sense system which utilizes the platform of ZigBee Network to collect and detect the real-time indoor environment quality. What’s more, Air-Sense system can also provide data analysis, and visualizing the results of the indoor environment to the user.

  4. Wireless sensor network-based greenhouse environment monitoring and automatic control system for dew condensation prevention.

    Science.gov (United States)

    Park, Dae-Heon; Park, Jang-Woo

    2011-01-01

    Dew condensation on the leaf surface of greenhouse crops can promote diseases caused by fungus and bacteria, affecting the growth of the crops. In this paper, we present a WSN (Wireless Sensor Network)-based automatic monitoring system to prevent dew condensation in a greenhouse environment. The system is composed of sensor nodes for collecting data, base nodes for processing collected data, relay nodes for driving devices for adjusting the environment inside greenhouse and an environment server for data storage and processing. Using the Barenbrug formula for calculating the dew point on the leaves, this system is realized to prevent dew condensation phenomena on the crop's surface acting as an important element for prevention of diseases infections. We also constructed a physical model resembling the typical greenhouse in order to verify the performance of our system with regard to dew condensation control.

  5. Digital Topographic Mapping in Urban Obstructed Environment Based on Multi-GNSS Network RTK Technology

    Science.gov (United States)

    Guo, Qiuying; Zhao, Tonglong; Zhang, Chao; Wu, Xuxiang

    2017-10-01

    Digital topographic mapping experiments were carried out based on network RTK technology using GPS/BEIDOU/GLONASS multi-constellation compatible GNSS receivers in urban obstructed environment. Operation scheme and technique flow were discussed. Experimental results show that the horizontal position and elevation of the points measured by RTK can reach 2cm and 3cm precision level respectively in open environment. RTK initialization time needs about 3-5s. While in obstructed environment, such as high building and tree shanding, the RTK initialization time needs about dozens of seconds or tens of seconds, and sometimes floating solutions or even differential solutions were obtained. The impact of dense and tall building on RTK measurement is more seriously. It is more likely to get RTK fixed solution in the south side of high building than the north side of the building.

  6. Population potential within the urban environment and intra-urban railway network opportunities in Bratislava (Slovakia

    Directory of Open Access Journals (Sweden)

    Ďurček Pavol

    2016-12-01

    Full Text Available Urban environments in post-socialist cities have generated new challenges for urban planners and decision makers. As one example, the transport infrastructure of Bratislava has not been adjusted with respect to increasing mobility and the transit problems of its intra-urban environment. An upgrading of the conventional railway networks within the city is one of the major opportunities which might considerably improve public transit capacities available for both intra-urban and regional (suburban transport flows of passengers. Relevant studies on the population potential of residents supporting such upgrades are still lacking. In addition, a detailed database on population distributions within the intra-urban environments of Slovak cities is not yet available. Therefore, this paper attempts to introduce one of the possible methodological approaches leading to an estimation of population potential as an elementary precondition of intra-urban railway traffic effectiveness, in a society where a detailed database on population distribution is not available.

  7. RF Path and Absorption Loss Estimation for Underwater Wireless Sensor Networks in Different Water Environments.

    Science.gov (United States)

    Qureshi, Umair Mujtaba; Shaikh, Faisal Karim; Aziz, Zuneera; Shah, Syed M Zafi S; Sheikh, Adil A; Felemban, Emad; Qaisar, Saad Bin

    2016-06-16

    Underwater Wireless Sensor Network (UWSN) communication at high frequencies is extremely challenging. The intricacies presented by the underwater environment are far more compared to the terrestrial environment. The prime reason for such intricacies are the physical characteristics of the underwater environment that have a big impact on electromagnetic (EM) signals. Acoustics signals are by far the most preferred choice for underwater wireless communication. Because high frequency signals have the luxury of large bandwidth (BW) at shorter distances, high frequency EM signals cannot penetrate and propagate deep in underwater environments. The EM properties of water tend to resist their propagation and cause severe attenuation. Accordingly, there are two questions that need to be addressed for underwater environment, first what happens when high frequency EM signals operating at 2.4 GHz are used for communication, and second which factors affect the most to high frequency EM signals. To answer these questions, we present real-time experiments conducted at 2.4 GHz in terrestrial and underwater (fresh water) environments. The obtained results helped in studying the physical characteristics (i.e., EM properties, propagation and absorption loss) of underwater environments. It is observed that high frequency EM signals can propagate in fresh water at a shallow depth only and can be considered for a specific class of applications such as water sports. Furthermore, path loss, velocity of propagation, absorption loss and the rate of signal loss in different underwater environments are also calculated and presented in order to understand why EM signals cannot propagate in sea water and oceanic water environments. An optimal solk6ution for underwater communication in terms of coverage distance, bandwidth and nature of communication is presented, along with possible underwater applications of UWSNs at 2.4 GHz.

  8. RF Path and Absorption Loss Estimation for Underwater Wireless Sensor Networks in Different Water Environments

    Directory of Open Access Journals (Sweden)

    Umair Mujtaba Qureshi

    2016-06-01

    Full Text Available Underwater Wireless Sensor Network (UWSN communication at high frequencies is extremely challenging. The intricacies presented by the underwater environment are far more compared to the terrestrial environment. The prime reason for such intricacies are the physical characteristics of the underwater environment that have a big impact on electromagnetic (EM signals. Acoustics signals are by far the most preferred choice for underwater wireless communication. Because high frequency signals have the luxury of large bandwidth (BW at shorter distances, high frequency EM signals cannot penetrate and propagate deep in underwater environments. The EM properties of water tend to resist their propagation and cause severe attenuation. Accordingly, there are two questions that need to be addressed for underwater environment, first what happens when high frequency EM signals operating at 2.4 GHz are used for communication, and second which factors affect the most to high frequency EM signals. To answer these questions, we present real-time experiments conducted at 2.4 GHz in terrestrial and underwater (fresh water environments. The obtained results helped in studying the physical characteristics (i.e., EM properties, propagation and absorption loss of underwater environments. It is observed that high frequency EM signals can propagate in fresh water at a shallow depth only and can be considered for a specific class of applications such as water sports. Furthermore, path loss, velocity of propagation, absorption loss and the rate of signal loss in different underwater environments are also calculated and presented in order to understand why EM signals cannot propagate in sea water and oceanic water environments. An optimal solk6ution for underwater communication in terms of coverage distance, bandwidth and nature of communication is presented, along with possible underwater applications of UWSNs at 2.4 GHz.

  9. Prediction of Thermal Environment in a Large Space Using Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Hyun-Jung Yoon

    2018-02-01

    Full Text Available Since the thermal environment of large space buildings such as stadiums can vary depending on the location of the stands, it is important to divide them into different zones and evaluate their thermal environment separately. The thermal environment can be evaluated using physical values measured with the sensors, but the occupant density of the stadium stands is high, which limits the locations available to install the sensors. As a method to resolve the limitations of installing the sensors, we propose a method to predict the thermal environment of each zone in a large space. We set six key thermal factors affecting the thermal environment in a large space to be predicted factors (indoor air temperature, mean radiant temperature, and clothing and the fixed factors (air velocity, metabolic rate, and relative humidity. Using artificial neural network (ANN models and the outdoor air temperature and the surface temperature of the interior walls around the stands as input data, we developed a method to predict the three thermal factors. Learning and verification datasets were established using STAR CCM+ (2016.10, Siemens PLM software, Plano, TX, USA. An analysis of each model’s prediction results showed that the prediction accuracy increased with the number of learning data points. The thermal environment evaluation process developed in this study can be used to control heating, ventilation, and air conditioning (HVAC facilities in each zone in a large space building with sufficient learning by ANN models at the building testing or the evaluation stage.

  10. Wave activity (planetary, tidal) throughout the middle atmosphere (20-100km) over the CUJO network: Satellite (TOMS) and Medium Frequency (MF) radar observations

    Science.gov (United States)

    Manson, A. H.; Meek, C. E.; Chshyolkova, T.; Avery, S. K.; Thorsen, D.; MacDougall, J. W.; Hocking, W.; Murayama, Y.; Igarashi, K.

    2005-02-01

    Planetary and tidal wave activity in the tropopause-lower stratosphere and mesosphere-lower thermosphere (MLT) is studied using combinations of ground-based (GB) and satellite instruments (2000-2002). The relatively new MFR (medium frequency radar) at Platteville (40° N, 105° W) has provided the opportunity to create an operational network of middle-latitude MFRs, stretching from 81° W-142° E, which provides winds and tides 70-100km. CUJO (Canada U.S. Japan Opportunity) comprises systems at London (43° N, 81° W), Platteville (40° N, 105° W), Saskatoon (52° N, 107° W), Wakkanai (45° N, 142° E) and Yamagawa (31° N, 131° E). It offers a significant 7000-km longitudinal sector in the North American-Pacific region, and a useful range of latitudes (12-14°) at two longitudes. Satellite data mainly involve the daily values of the total ozone column measured by the Earth Probe (EP) TOMS (Total Ozone Mapping Spectrometer) and provide a measure of tropopause-lower stratospheric planetary wave activity, as well as ozone variability. Climatologies of ozone and winds/tides involving frequency versus time (wavelet) contour plots for periods from 2-d to 30-d and the interval from mid 2000 to 2002, show that the changes with altitude, longitude and latitude are very significant and distinctive. Geometric-mean wavelets for the region of the 40° N MFRs demonstrate occasions during the autumn, winter and spring months when there are similarities in the spectral features of the lower atmosphere and at mesopause (85km) heights. Both direct planetary wave (PW) propagation into the MLT, nonlinear PW-tide interactions, and disturbances in MLT tides associated with fluctuations in the ozone forcing are considered to be possible coupling processes. The complex horizontal wave numbers of the longer period oscillations are provided in frequency contour plots for the TOMS satellite data to demonstrate the differences between lower atmospheric and MLT wave motions and their

  11. Wave activity (planetary, tidal throughout the middle atmosphere (20-100km over the CUJO network: Satellite (TOMS and Medium Frequency (MF radar observations

    Directory of Open Access Journals (Sweden)

    A. H. Manson

    2005-02-01

    Full Text Available Planetary and tidal wave activity in the tropopause-lower stratosphere and mesosphere-lower thermosphere (MLT is studied using combinations of ground-based (GB and satellite instruments (2000-2002. The relatively new MFR (medium frequency radar at Platteville (40° N, 105° W has provided the opportunity to create an operational network of middle-latitude MFRs, stretching from 81° W-142° E, which provides winds and tides 70-100km. CUJO (Canada U.S. Japan Opportunity comprises systems at London (43° N, 81° W, Platteville (40° N, 105° W, Saskatoon (52° N, 107° W, Wakkanai (45° N, 142° E and Yamagawa (31° N, 131° E. It offers a significant 7000-km longitudinal sector in the North American-Pacific region, and a useful range of latitudes (12-14° at two longitudes. Satellite data mainly involve the daily values of the total ozone column measured by the Earth Probe (EP TOMS (Total Ozone Mapping Spectrometer and provide a measure of tropopause-lower stratospheric planetary wave activity, as well as ozone variability.

    Climatologies of ozone and winds/tides involving frequency versus time (wavelet contour plots for periods from 2-d to 30-d and the interval from mid 2000 to 2002, show that the changes with altitude, longitude and latitude are very significant and distinctive. Geometric-mean wavelets for the region of the 40° N MFRs demonstrate occasions during the autumn, winter and spring months when there are similarities in the spectral features of the lower atmosphere and at mesopause (85km heights. Both direct planetary wave (PW propagation into the MLT, nonlinear PW-tide interactions, and disturbances in MLT tides associated with fluctuations in the ozone forcing are considered to be possible coupling processes. The complex horizontal wave numbers of the longer period oscillations are provided in frequency contour plots for the TOMS satellite data to demonstrate the differences between lower atmospheric

  12. Anatomy and histology as socially networked learning environments: some preliminary findings.

    Science.gov (United States)

    Hafferty, Frederic W; Castellani, Brian; Hafferty, Philip K; Pawlina, Wojciech

    2013-09-01

    An exploratory study to better understand the "networked" life of the medical school as a learning environment. In a recent academic year, the authors gathered data during two six-week blocks of a sequential histology and anatomy course at a U.S. medical college. An eight-item questionnaire captured different dimensions of student interactions. The student cohort/network was 48 first-year medical students. Using social network analysis (SNA), the authors focused on (1) the initial structure and the evolution of informal class networks over time, (2) how informal class networks compare to formal in-class small-group assignments in influencing student information gathering, and (3) how peer assignment of professionalism role model status is shaped more by informal than formal ties. In examining these latter two issues, the authors explored not only how formal group assignment persisted over time but also how it functioned to prevent the tendency for groupings based on gender or ethnicity. The study revealed an evolving dynamic between the formal small-group learning structure of the course blocks and the emergence of informal student networks. For example, whereas formal group membership did influence in-class questions and did prevent formation of groups of like gender and ethnicity, outside-class questions and professionalism were influenced more by informal group ties where gender and, to a much lesser extent, ethnicity influence student information gathering. The richness of these preliminary findings suggests that SNA may be a useful tool in examining an array of medical student learning encounters.

  13. Comparison of simulated and actual wind shear radar data products

    Science.gov (United States)

    Britt, Charles L.; Crittenden, Lucille H.

    1992-01-01

    Prior to the development of the NASA experimental wind shear radar system, extensive computer simulations were conducted to determine the performance of the radar in combined weather and ground clutter environments. The simulation of the radar used analytical microburst models to determine weather returns and synthetic aperture radar (SAR) maps to determine ground clutter returns. These simulations were used to guide the development of hazard detection algorithms and to predict their performance. The structure of the radar simulation is reviewed. Actual flight data results from the Orlando and Denver tests are compared with simulated results. Areas of agreement and disagreement of actual and simulated results are shown.

  14. THE APPLICATION OF DIGITAL LINE GRAPHS AND MAP IN THE NETWORK ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    X. Guo

    2012-07-01

    Full Text Available WebGIS is an important research field in GIS. W3C organization established SVG standard, which laid a foundation for WebGIS based on vector data. In China, Digital Line Graphs(DLG is a significant GIS product and it has been used in many medium and large WebGIS system. Geographic information-portrayal is the common method of DLG visualization. However, the inherent characteristics of Geographic information-portrayal may lead to a relatively higher data production input, still, the visualization effect is not ideal. We put forward a new product named Digital Line Graphs and Map(DLGM, which consists of DLG and DLG's cartographic presentation data. It provides visualization data based on the cartographic standards. Due to the manufacture and management of DLGM data that are independent from software and platform, its data can be used in many fields. Network application is one of them. This paper is to use DLGM in the network applications. First it reveals the connotation and characteristics of DLGM then analyses the model that DLGM organizes, manages DLG and map symbol data. After that, combined with SVG standards, we put forward DLGM’s SVG encoding method without any information loss. Finally we provide a web map system based on local area network by using 1:10000 DLGM data of a certain area. Based on this study, we conclude that DLGM can be used in the network environment providing high quality DLG and cartographic data for WebGIS.

  15. The Application of Digital Line Graphs and Map in the Network Environment

    Science.gov (United States)

    Guo, X.; Zhang, B.; Yu, J.; Ran, H.; Wang, L.

    2012-07-01

    WebGIS is an important research field in GIS. W3C organization established SVG standard, which laid a foundation for WebGIS based on vector data. In China, Digital Line Graphs(DLG) is a significant GIS product and it has been used in many medium and large WebGIS system. Geographic information-portrayal is the common method of DLG visualization. However, the inherent characteristics of Geographic information-portrayal may lead to a relatively higher data production input, still, the visualization effect is not ideal. We put forward a new product named Digital Line Graphs and Map(DLGM), which consists of DLG and DLG's cartographic presentation data. It provides visualization data based on the cartographic standards. Due to the manufacture and management of DLGM data that are independent from software and platform, its data can be used in many fields. Network application is one of them. This paper is to use DLGM in the network applications. First it reveals the connotation and characteristics of DLGM then analyses the model that DLGM organizes, manages DLG and map symbol data. After that, combined with SVG standards, we put forward DLGM's SVG encoding method without any information loss. Finally we provide a web map system based on local area network by using 1:10000 DLGM data of a certain area. Based on this study, we conclude that DLGM can be used in the network environment providing high quality DLG and cartographic data for WebGIS.

  16. Two-round contributory group key exchange protocol for wireless network environments

    Directory of Open Access Journals (Sweden)

    Wu Tsu-Yang

    2011-01-01

    Full Text Available Abstract With the popularity of group-oriented applications, secure group communication has recently received much attention from cryptographic researchers. A group key exchange (GKE protocol allows that participants cooperatively establish a group key that is used to encrypt and decrypt transmitted messages. Hence, GKE protocols can be used to provide secure group communication over a public network channel. However, most of the previously proposed GKE protocols deployed in wired networks are not fully suitable for wireless network environments with low-power computing devices. Subsequently, several GKE protocols suitable for mobile or wireless networks have been proposed. In this article, we will propose a more efficient group key exchange protocol with dynamic joining and leaving. Under the decision Diffie-Hellman (DDH, the computation Diffie-Hellman (CDH, and the hash function assumptions, we demonstrate that the proposed protocol is secure against passive attack and provides forward/backward secrecy for dynamic member joining/leaving. As compared with the recently proposed GKE protocols, our protocol provides better performance in terms of computational cost, round number, and communication cost.

  17. Next-Generation Environment-Aware Cellular Networks: Modern Green Techniques and Implementation Challenges

    KAUST Repository

    Ghazzai, Hakim

    2016-09-16

    Over the last decade, mobile communications have been witnessing a noteworthy increase of data traffic demand that is causing an enormous energy consumption in cellular networks. The reduction of their fossil fuel consumption in addition to the huge energy bills paid by mobile operators is considered as the most important challenges for the next-generation cellular networks. Although most of the proposed studies were focusing on individual physical layer power optimizations, there is a growing necessity to meet the green objective of fifth-generation cellular networks while respecting the user\\'s quality of service. This paper investigates four important techniques that could be exploited separately or together in order to enable wireless operators achieve significant economic benefits and environmental savings: 1) the base station sleeping strategy; 2) the optimized energy procurement from the smart grid; 3) the base station energy sharing; and 4) the green networking collaboration between competitive mobile operators. The presented simulation results measure the gain that could be obtained using these techniques compared with that of traditional scenarios. Finally, this paper discusses the issues and challenges related to the implementations of these techniques in real environments. © 2016 IEEE.

  18. Path planning in GPS-denied environments via collective intelligence of distributed sensor networks

    Science.gov (United States)

    Jha, Devesh K.; Chattopadhyay, Pritthi; Sarkar, Soumik; Ray, Asok

    2016-05-01

    This paper proposes a framework for reactive goal-directed navigation without global positioning facilities in unknown dynamic environments. A mobile sensor network is used for localising regions of interest for path planning of an autonomous mobile robot. The underlying theory is an extension of a generalised gossip algorithm that has been recently developed in a language-measure-theoretic setting. The algorithm has been used to propagate local decisions of target detection over a mobile sensor network and thus, it generates a belief map for the detected target over the network. In this setting, an autonomous mobile robot may communicate only with a few mobile sensing nodes in its own neighbourhood and localise itself relative to the communicating nodes with bounded uncertainties. The robot makes use of the knowledge based on the belief of the mobile sensors to generate a sequence of way-points, leading to a possible goal. The estimated way-points are used by a sampling-based motion planning algorithm to generate feasible trajectories for the robot. The proposed concept has been validated by numerical simulation on a mobile sensor network test-bed and a Dubin's car-like robot.

  19. A Representation Method for Complex Road Networks in Virtual Geographic Environments

    Directory of Open Access Journals (Sweden)

    Peibei Zheng

    2017-11-01

    Full Text Available Road networks are important for modelling the urban geographic environment. It is necessary to determine the spatial relationships of road intersections when using maps to help researchers conduct virtual urban geographic experiments (because a road intersection might occur as a connected cross or as an unconnected bridge overpass. Based on the concept of using different map layers to organize the render order of each road segment, three methods (manual, semi-automatic and mask-based automatic are available to help map designers arrange the rendering order. However, significant efforts are still needed, and rendering efficiency remains problematic with these methods. This paper considers the Discrete, Crossing, Overpass, Underpass, Conjunction, Up-overlap and Down-overlap spatial relationships of road intersections. An automatic method is proposed to represent these spatial relationships when drawing road networks on a map. The data-layer organization method (reflecting road grade and elevation-level information and the symbol-layer decomposition method (reflecting road covering order in the vertical direction are designed to determine the rendering order of each road element when rendering a map. In addition, an “auxiliary-drawing-action” (for drawing road segments belonging to different grades and elevations is proposed to adjust the rendering sequences automatically. Two experiments are conducted to demonstrate the feasibility and efficiency of the method, and the results demonstrate that it can effectively handle spatial relationships of road networks in map representations. Using the proposed method, the difficulty of rendering complex road networks can be reduced.

  20. Radar and ARPA manual

    CERN Document Server

    Bole, A G

    2013-01-01

    Radar and ARPA Manual focuses on the theoretical and practical aspects of electronic navigation. The manual first discusses basic radar principles, including principles of range and bearing measurements and picture orientation and presentation. The text then looks at the operational principles of radar systems. Function of units; aerial, receiver, and display principles; transmitter principles; and sitting of units on board ships are discussed. The book also describes target detection, Automatic Radar Plotting Aids (ARPA), and operational controls of radar systems, and then discusses radar plo

  1. Adaptive radar resource management

    CERN Document Server

    Moo, Peter

    2015-01-01

    Radar Resource Management (RRM) is vital for optimizing the performance of modern phased array radars, which are the primary sensor for aircraft, ships, and land platforms. Adaptive Radar Resource Management gives an introduction to radar resource management (RRM), presenting a clear overview of different approaches and techniques, making it very suitable for radar practitioners and researchers in industry and universities. Coverage includes: RRM's role in optimizing the performance of modern phased array radars The advantages of adaptivity in implementing RRMThe role that modelling and

  2. The proposed flatland radar

    Science.gov (United States)

    Green, J. L.; Gage, K. S.; Vanzandt, T. E.; Nastrom, G. D.

    1986-01-01

    A flexible very high frequency (VHF) stratosphere-troposphere (ST) radar configured for meteorological research is to be constructed near Urbana, Illinois. Measurement of small vertical velocities associated with synoptic-scale meteorology can be performed. A large Doppler microwave radar (CHILL) is located a few km from the site of the proposed ST radar. Since the microwave radar can measure the location and velocity of hydrometeors and the VHF ST radar can measure clear (or cloudy) air velocities, simultaneous observations by these two radars of stratiform or convective weather systems would provide valuable meteorological information.

  3. Differential recruitment of brain networks following route and cartographic map learning of spatial environments.

    Science.gov (United States)

    Zhang, Hui; Copara, Milagros; Ekstrom, Arne D

    2012-01-01

    An extensive neuroimaging literature has helped characterize the brain regions involved in navigating a spatial environment. Far less is known, however, about the brain networks involved when learning a spatial layout from a cartographic map. To compare the two means of acquiring a spatial representation, participants learned spatial environments either by directly navigating them or learning them from an aerial-view map. While undergoing functional magnetic resonance imaging (fMRI), participants then performed two different tasks to assess knowledge of the spatial environment: a scene and orientation dependent perceptual (SOP) pointing task and a judgment of relative direction (JRD) of landmarks pointing task. We found three brain regions showing significant effects of route vs. map learning during the two tasks. Parahippocampal and retrosplenial cortex showed greater activation following route compared to map learning during the JRD but not SOP task while inferior frontal gyrus showed greater activation following map compared to route learning during the SOP but not JRD task. We interpret our results to suggest that parahippocampal and retrosplenial cortex were involved in translating scene and orientation dependent coordinate information acquired during route learning to a landmark-referenced representation while inferior frontal gyrus played a role in converting primarily landmark-referenced coordinates acquired during map learning to a scene and orientation dependent coordinate system. Together, our results provide novel insight into the different brain networks underlying spatial representations formed during navigation vs. cartographic map learning and provide additional constraints on theoretical models of the neural basis of human spatial representation.

  4. Network-based Parallel Retrieval Onboard Computing Environment for Sensor Systems Deployed on NASA Unmanned Aircraft Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Remote Sensing Solutions proposes to develop the Network-based Parallel Retrieval Onboard Computing Environment for Sensor Systems (nPROCESS) for deployment on...

  5. From Smart Guesser to Smart Navigator: Changes in Collection Development for Research Libraries in a Network Environment.

    Science.gov (United States)

    Zhou, Yuan

    1994-01-01

    Discusses the impact that network technology, electronic publishing, and Internet communication are having on collection development policies in research libraries. Highlights include changes in the research library environment, including financial difficulties; scholarly communication; workstations for material selection; and materials in…

  6. Analysis of Energy Consumption Performance towards Optimal Radioplanning of Wireless Sensor Networks in Heterogeneous Indoor Environments

    Directory of Open Access Journals (Sweden)

    P. Lopez Iturri

    2014-09-01

    Full Text Available In this paper the impact of complex indoor environment in the deployment and energy consumption of a wireless sensor network infrastructure is analyzed. The variable nature of the radio channel is analyzed by means of deterministic in-house 3D ray launching simulation of an indoor scenario, in which wireless sensors, based on an in-house CyFi implementation, typically used for environmental monitoring, are located. Received signal power and current consumption measurement results of the in-house designed wireless motes have been obtained, stating that adequate consideration of the network topology and morphology lead to optimal performance and power consumption reduction. The use of radioplanning techniques therefore aid in the deployment of more energy efficient elements, optimizing the overall performance of the variety of deployed wireless systems within the indoor scenario.

  7. McGill algorithm for precipitation nowcasting by lagrangian extrapolation (MAPLE) applied to the South Korean radar network. Part I: Sensitivity studies of the Variational Echo Tracking (VET) technique

    Science.gov (United States)

    Bellon, Aldo; Zawadzki, Isztar; Kilambi, Alamelu; Lee, Hee Choon; Lee, Yong Hee; Lee, Gyuwon

    2010-08-01

    A Variational Echo Tracking (VET) technique has been applied to four months of archived data from the South Korean radar network in order to examine the influence of the various user-selectable parameters on the skill of the resulting 20-min to 4-h nowcasts. The latter are computed over a (512 × 512) array at 2-km resolution. After correcting the original algorithm to take into account the motion of precipitation across the boundaries of such a smaller radar network, we concluded that the set of default input parameters initially assumed is very close to the optimum combination. Decreasing to (5 sx 5) or increasing to (50 × 50) the default vector density of (25 × 25), using two or three maps for velocity determination, varying the relative weights for the constraints of conservation of reflectivity and of the smoothing of the velocity vectors, and finally the application of temporal smoothing all had only marginal effects on the skill of the forecasts. The relatively small sensitivity to significant variations of the VET default parameters is a direct consequence of the fact that the major source of the loss in forecast skill cannot be attributed to errors in the forecast motion, but to the unpredictable nature of the storm growth and decay. Changing the time interval between maps, from 20 to 10 minutes, and significantly increasing the reflectivity threshold from 15 to 30 dBZ had a more noticeable reduction on the forecast skill. Comparisons with the Eulerian "zero velocity" forecast and with a "single" vector forecast have also been performed in order to determine the accrued skill of the VET algorithm. Because of the extensive stratiform nature of the precipitation areas affecting the Korean peninsula, the increased skill is not as large as may have been anticipated. This can be explained by the greater extent of the precipitation systems relative to the size of the radar coverage domain.

  8. Studies on Radar Sensor Networks

    Science.gov (United States)

    2007-08-08

    propagation in three (see Fig. 4). In the S-V model, the magnitude of the k-th cases: near field (less than 55m ), medium field ( 55m - path within the l...return at angle Oim and Doppler shift fi,. where iis a ty estim td n eri in tar e , t seso ible Si (U,t) = [al(u)sli(t),a 2(u )s 2i(t), ... ,aM,(U)SM

  9. A Survey on Wireless Body Area Networks for eHealthcare Systems in Residential Environments

    Directory of Open Access Journals (Sweden)

    Mohammad Ghamari

    2016-06-01

    Full Text Available Current progress in wearable and implanted health monitoring technologies has strong potential to alter the future of healthcare services by enabling ubiquitous monitoring of patients. A typical health monitoring system consists of a network of wearable or implanted sensors that constantly monitor physiological parameters. Collected data are relayed using existing wireless communication protocols to a base station for additional processing. This article provides researchers with information to compare the existing low-power communication technologies that can potentially support the rapid development and deployment of WBAN systems, and mainly focuses on remote monitoring of elderly or chronically ill patients in residential environments.

  10. Virtual Community, social network and media environment of Canary Isands regional digital newspapers

    Directory of Open Access Journals (Sweden)

    Dr. Francisco Manuel Mateos Rodríguez

    2008-01-01

    Full Text Available The impact of the new communication and information technologies has favoured the creation of multiple local newspaper websites in the Canary Islands, thus making the regional press emerge as an alternative on the rise. This tendency affects significantly both traditional and new editions of the different regional and local newspapers from the Canaries and motivates a different distribution, positioning and development within the local media environment in which these media share a novel dimension of communication with a specific virtual community and social network within the World Wide Web.

  11. Advanced Architectures for Modern Weather/Multifunction Radars

    Science.gov (United States)

    2017-03-01

    simulations for such a large conformal array, but that the system has successfully operated as a functioning radar . An early example of the latter...per polarization. 86 For normal radar operation , digital beamforming will be accomplished over a RapidIO network feeding the back of the LRUs...open up a new paradigm in weather radar capabilities and operational modalities, for both operational and research-oriented systems. The University

  12. Verification of satellite radar remote sensing based estimates of boreal and subalpine growing seasons using an ecosystem process model and surface biophysical measurement network information

    Science.gov (United States)

    McDonald, K. C.; Kimball, J. S.; Zimmerman, R.

    2002-01-01

    We employ daily surface Radar backscatter data from the SeaWinds Ku-band Scatterometer onboard Quikscat to estimate landscape freeze-thaw state and associated length of the seasonal non-frozen period as a surrogate for determining the annual growing season across boreal and subalpine regions of North America for 2000 and 2001.

  13. Spontaneous fine-tuning to environment in many-species chemical reaction networks

    Science.gov (United States)

    Horowitz, Jordan M.; England, Jeremy L.

    2017-07-01

    A chemical mixture that continually absorbs work from its environment may exhibit steady-state chemical concentrations that deviate from their equilibrium values. Such behavior is particularly interesting in a scenario where the environmental work sources are relatively difficult to access, so that only the proper orchestration of many distinct catalytic actors can power the dissipative flux required to maintain a stable, far-from-equilibrium steady state. In this article, we study the dynamics of an in silico chemical network with random connectivity in an environment that makes strong thermodynamic forcing available only to rare combinations of chemical concentrations. We find that the long-time dynamics of such systems are biased toward states that exhibit a fine-tuned extremization of environmental forcing.

  14. Spontaneous fine-tuning to environment in many-species chemical reaction networks.

    Science.gov (United States)

    Horowitz, Jordan M; England, Jeremy L

    2017-07-18

    A chemical mixture that continually absorbs work from its environment may exhibit steady-state chemical concentrations that deviate from their equilibrium values. Such behavior is particularly interesting in a scenario where the environmental work sources are relatively difficult to access, so that only the proper orchestration of many distinct catalytic actors can power the dissipative flux required to maintain a stable, far-from-equilibrium steady state. In this article, we study the dynamics of an in silico chemical network with random connectivity in an environment that makes strong thermodynamic forcing available only to rare combinations of chemical concentrations. We find that the long-time dynamics of such systems are biased toward states that exhibit a fine-tuned extremization of environmental forcing.

  15. Principles of modern radar systems

    CERN Document Server

    Carpentier, Michel H

    1988-01-01

    Introduction to random functions ; signal and noise : the ideal receiver ; performance of radar systems equipped with ideal receivers ; analysis of the operating principles of some types of radar ; behavior of real targets, fluctuation of targets ; angle measurement using radar ; data processing of radar information, radar coverage ; applications to electronic scanning antennas to radar ; introduction to Hilbert spaces.

  16. Weather Radar Impact Zones

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data represent an inventory of the national impacts of wind turbine interference with NEXRAD radar stations. This inventory was developed by the NOAA Radar...

  17. A Novel Energy-Aware Distributed Clustering Algorithm for Heterogeneous Wireless Sensor Networks in the Mobile Environment.

    Science.gov (United States)

    Gao, Ying; Wkram, Chris Hadri; Duan, Jiajie; Chou, Jarong

    2015-12-10

    In order to prolong the network lifetime, energy-efficient protocols adapted to the features of wireless sensor networks should be used. This paper explores in depth the nature of heterogeneous wireless sensor networks, and finally proposes an algorithm to address the problem of finding an effective pathway for heterogeneous clustering energy. The proposed algorithm implements cluster head selection according to the degree of energy attenuation during the network's running and the degree of candidate nodes' effective coverage on the whole network, so as to obtain an even energy consumption over the whole network for the situation with high degree of coverage. Simulation results show that the proposed clustering protocol has better adaptability to heterogeneous environments than existing clustering algorithms in prolonging the network lifetime.

  18. Incremental online object learning in a vehicular radar-vision fusion framework

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Zhengping [Los Alamos National Laboratory; Weng, Juyang [Los Alamos National Laboratory; Luciw, Matthew [IEEE; Zeng, Shuqing [IEEE

    2010-10-19

    In this paper, we propose an object learning system that incorporates sensory information from an automotive radar system and a video camera. The radar system provides a coarse attention for the focus of visual analysis on relatively small areas within the image plane. The attended visual areas are coded and learned by a 3-layer neural network utilizing what is called in-place learning, where every neuron is responsible for the learning of its own signal processing characteristics within its connected network environment, through inhibitory and excitatory connections with other neurons. The modeled bottom-up, lateral, and top-down connections in the network enable sensory sparse coding, unsupervised learning and supervised learning to occur concurrently. The presented work is applied to learn two types of encountered objects in multiple outdoor driving settings. Cross validation results show the overall recognition accuracy above 95% for the radar-attended window images. In comparison with the uncoded representation and purely unsupervised learning (without top-down connection), the proposed network improves the recognition rate by 15.93% and 6.35% respectively. The proposed system is also compared with other learning algorithms favorably. The result indicates that our learning system is the only one to fit all the challenging criteria for the development of an incremental and online object learning system.

  19. Detecting Rumors Through Modeling Information Propagation Networks in a Social Media Environment.

    Science.gov (United States)

    Liu, Yang; Xu, Songhua; Tourassi, Georgia

    2015-01-01

    In the midst of today's pervasive influence of social media content and activities, information credibility has increasingly become a major issue. Accordingly, identifying false information, e.g. rumors circulated in social media environments, attracts expanding research attention and growing interests. Many previous studies have exploited user-independent features for rumor detection. These prior investigations uniformly treat all users relevant to the propagation of a social media message as instances of a generic entity. Such a modeling approach usually adopts a homogeneous network to represent all users, the practice of which ignores the variety across an entire user population in a social media environment. Recognizing this limitation of modeling methodologies, this study explores user-specific features in a social media environment for rumor detection. The new approach hypothesizes that whether a user tends to spread a rumor is dependent upon specific attributes of the user in addition to content characteristics of the message itself. Under this hypothesis, information propagation patterns of rumors versus those of credible messages in a social media environment are systematically differentiable. To explore and exploit this hypothesis, we develop a new information propagation model based on a heterogeneous user representation for rumor recognition. The new approach is capable of differentiating rumors from credible messages through observing distinctions in their respective propagation patterns in social media. Experimental results show that the new information propagation model based on heterogeneous user representation can effectively distinguish rumors from credible social media content.

  20. Design of a water environment monitoring system based on wireless sensor networks.

    Science.gov (United States)

    Jiang, Peng; Xia, Hongbo; He, Zhiye; Wang, Zheming

    2009-01-01

    A water environmental monitoring system based on a wireless sensor network is proposed. It consists of three parts: data monitoring nodes, data base station and remote monitoring center. This system is suitable for the complex and large-scale water environment monitoring, such as for reservoirs, lakes, rivers, swamps, and shallow or deep groundwaters. This paper is devoted to the explanation and illustration for our new water environment monitoring system design. The system had successfully accomplished the online auto-monitoring of the water temperature and pH value environment of an artificial lake. The system's measurement capacity ranges from 0 to 80 °C for water temperature, with an accuracy of ±0.5 °C; from 0 to 14 on pH value, with an accuracy of ±0.05 pH units. Sensors applicable to different water quality scenarios should be installed at the nodes to meet the monitoring demands for a variety of water environments and to obtain different parameters. The monitoring system thus promises broad applicability prospects.

  1. Radar: Human Safety Net

    Science.gov (United States)

    Ritz, John M.

    2016-01-01

    Radar is a technology that can be used to detect distant objects not visible to the human eye. A predecessor of radar, called the telemobiloscope, was first used to detect ships in the fog in 1904 off the German coast. Many scientists have worked on the development and refinement of radar (Hertz with electromagnetic waves; Popov with determining…

  2. Software Radar Technology

    Directory of Open Access Journals (Sweden)

    Tang Jun

    2015-08-01

    Full Text Available In this paper, the definition and the key features of Software Radar, which is a new concept, are proposed and discussed. We consider the development of modern radar system technology to be divided into three stages: Digital Radar, Software radar and Intelligent Radar, and the second stage is just commencing now. A Software Radar system should be a combination of various modern digital modular components conformed to certain software and hardware standards. Moreover, a software radar system with an open system architecture supporting to decouple application software and low level hardware would be easy to adopt "user requirements-oriented" developing methodology instead of traditional "specific function-oriented" developing methodology. Compared with traditional Digital Radar, Software Radar system can be easily reconfigured and scaled up or down to adapt to the changes of requirements and technologies. A demonstration Software Radar signal processing system, RadarLab 2.0, which has been developed by Tsinghua University, is introduced in this paper and the suggestions for the future development of Software Radar in China are also given in the conclusion.

  3. Sensing Coverage Prediction for Wireless Sensor Networks in Shadowed and Multipath Environment

    Directory of Open Access Journals (Sweden)

    Sushil Kumar

    2013-01-01

    Full Text Available Sensing coverage problem in wireless sensor networks is a measure of quality of service (QoS. Coverage refers to how well a sensing field is monitored or tracked by the sensors. Aim of the paper is to have a priori estimate for number of sensors to be deployed in a harsh environment to achieve desired coverage. We have proposed a new sensing channel model that considers combined impact of shadowing fading and multipath effects. A mathematical model for calculating coverage probability in the presence of multipath fading combined with shadowing is derived based on received signal strength (RSS. Further, the coverage probability derivations obtained using Rayleigh fading and lognormal shadowing fading are validated by node deployment using Poisson distribution. A comparative study between our proposed sensing channel model and different existing sensing models for the network coverage has also been presented. Our proposed sensing model is more suitable for realistic environment since it determines the optimum number of sensors required for desirable coverage in fading conditions.

  4. Unmanned Aerial Vehicle Based Wireless Sensor Network for Marine-Coastal Environment Monitoring.

    Science.gov (United States)

    Trasviña-Moreno, Carlos A; Blasco, Rubén; Marco, Álvaro; Casas, Roberto; Trasviña-Castro, Armando

    2017-02-24

    Marine environments are delicate ecosystems which directly influence local climates, flora, fauna, and human activities. Their monitorization plays a key role in their preservation, which is most commonly done through the use of environmental sensing buoy networks. These devices transmit data by means of satellite communications or close-range base stations, which present several limitations and elevated infrastructure costs. Unmanned Aerial Vehicles (UAV) are another alternative for remote environmental monitoring which provide new types of data and ease of use. These aircraft are mainly used in video capture related applications, in its various light spectrums, and do not provide the same data as sensing buoys, nor can they be used for such extended periods of time. The aim of this research is to provide a flexible, easy to deploy and cost-effective Wireless Sensor Network (WSN) for monitoring marine environments. This proposal uses a UAV as a mobile data collector, low-power long-range communications and sensing buoys as part of a single WSN. A complete description of the design, development, and implementation of the various parts of this system is presented, as well as its validation in a real-world scenario.

  5. Unmanned Aerial Vehicle Based Wireless Sensor Network for Marine-Coastal Environment Monitoring

    Directory of Open Access Journals (Sweden)

    Carlos A. Trasviña-Moreno

    2017-02-01

    Full Text Available Marine environments are delicate ecosystems which directly influence local climates, flora, fauna, and human activities. Their monitorization plays a key role in their preservation, which is most commonly done through the use of environmental sensing buoy networks. These devices transmit data by means of satellite communications or close-range base stations, which present several limitations and elevated infrastructure costs. Unmanned Aerial Vehicles (UAV are another alternative for remote environmental monitoring which provide new types of data and ease of use. These aircraft are mainly used in video capture related applications, in its various light spectrums, and do not provide the same data as sensing buoys, nor can they be used for such extended periods of time. The aim of this research is to provide a flexible, easy to deploy and cost-effective Wireless Sensor Network (WSN for monitoring marine environments. This proposal uses a UAV as a mobile data collector, low-power long-range communications and sensing buoys as part of a single WSN. A complete description of the design, development, and implementation of the various parts of this system is presented, as well as its validation in a real-world scenario.

  6. Using Web 2.0 Techniques in NASA's Ares Engineering Operations Network (AEON) Environment - First Impressions

    Science.gov (United States)

    Scott, David W.

    2010-01-01

    The Mission Operations Laboratory (MOL) at Marshall Space Flight Center (MSFC) is responsible for Engineering Support capability for NASA s Ares rocket development and operations. In pursuit of this, MOL is building the Ares Engineering and Operations Network (AEON), a web-based portal to support and simplify two critical activities: Access and analyze Ares manufacturing, test, and flight performance data, with access to Shuttle data for comparison Establish and maintain collaborative communities within the Ares teams/subteams and with other projects, e.g., Space Shuttle, International Space Station (ISS). AEON seeks to provide a seamless interface to a) locally developed engineering applications and b) a Commercial-Off-The-Shelf (COTS) collaborative environment that includes Web 2.0 capabilities, e.g., blogging, wikis, and social networking. This paper discusses how Web 2.0 might be applied to the typically conservative engineering support arena, based on feedback from Integration, Verification, and Validation (IV&V) testing and on searching for their use in similar environments.

  7. A convolutional neural network for steady state visual evoked potential classification under ambulatory environment

    Science.gov (United States)

    Kwak, No-Sang; Müller, Klaus-Robert

    2017-01-01

    The robust analysis of neural signals is a challenging problem. Here, we contribute a convolutional neural network (CNN) for the robust classification of a steady-state visual evoked potentials (SSVEPs) paradigm. We measure electroencephalogram (EEG)-based SSVEPs for a brain-controlled exoskeleton under ambulatory conditions in which numerous artifacts may deteriorate decoding. The proposed CNN is shown to achieve reliable performance under these challenging conditions. To validate the proposed method, we have acquired an SSVEP dataset under two conditions: 1) a static environment, in a standing position while fixated into a lower-limb exoskeleton and 2) an ambulatory environment, walking along a test course wearing the exoskeleton (here, artifacts are most challenging). The proposed CNN is compared to a standard neural network and other state-of-the-art methods for SSVEP decoding (i.e., a canonical correlation analysis (CCA)-based classifier, a multivariate synchronization index (MSI), a CCA combined with k-nearest neighbors (CCA-KNN) classifier) in an offline analysis. We found highly encouraging SSVEP decoding results for the CNN architecture, surpassing those of other methods with classification rates of 99.28% and 94.03% in the static and ambulatory conditions, respectively. A subsequent analysis inspects the representation found by the CNN at each layer and can thus contribute to a better understanding of the CNN’s robust, accurate decoding abilities. PMID:28225827

  8. A convolutional neural network for steady state visual evoked potential classification under ambulatory environment.

    Science.gov (United States)

    Kwak, No-Sang; Müller, Klaus-Robert; Lee, Seong-Whan

    2017-01-01

    The robust analysis of neural signals is a challenging problem. Here, we contribute a convolutional neural network (CNN) for the robust classification of a steady-state visual evoked potentials (SSVEPs) paradigm. We measure electroencephalogram (EEG)-based SSVEPs for a brain-controlled exoskeleton under ambulatory conditions in which numerous artifacts may deteriorate decoding. The proposed CNN is shown to achieve reliable performance under these challenging conditions. To validate the proposed method, we have acquired an SSVEP dataset under two conditions: 1) a static environment, in a standing position while fixated into a lower-limb exoskeleton and 2) an ambulatory environment, walking along a test course wearing the exoskeleton (here, artifacts are most challenging). The proposed CNN is compared to a standard neural network and other state-of-the-art methods for SSVEP decoding (i.e., a canonical correlation analysis (CCA)-based classifier, a multivariate synchronization index (MSI), a CCA combined with k-nearest neighbors (CCA-KNN) classifier) in an offline analysis. We found highly encouraging SSVEP decoding results for the CNN architecture, surpassing those of other methods with classification rates of 99.28% and 94.03% in the static and ambulatory conditions, respectively. A subsequent analysis inspects the representation found by the CNN at each layer and can thus contribute to a better understanding of the CNN's robust, accurate decoding abilities.

  9. The effect of railway network evolution on the Kaliningrad region’s landscape environment

    Directory of Open Access Journals (Sweden)

    Romanova Elena

    2015-12-01

    Full Text Available This article addresses methodology of modern landscape studies from the perspective of natural and man-made components of a territory. Railway infrastructure is not only an important system-building element of economic and settlement patterns; it also affects cultural landscapes. The study of cartographic materials and historiography made it possible to identify the main stages of the development of the Kaliningrad railway network in terms of its territorial scope and to describe causes of the observed changes. Historically, changes in the political, economic, and military environment were key factors behind the development of the Kaliningrad railway network. Nature was less important. The existing Kaliningrad railway network is to a great degree the legacy of the earlier, pre-war times. Today, its primary function is to provide international cargo and passenger transportation. Two types of railway infrastructure are identified in the Kaliningrad region – modern (functioning and relic (abandoned ones. In the Kaliningrad region, the process of land reclamation of the railway system starts when the maintenance of railroads is discontinued, which is followed by the formation of primitive soils and emerging biocenoses enhanced by fill soils and artificial relief.

  10. Providing QoS for Networked Peers in Distributed Haptic Virtual Environments

    Directory of Open Access Journals (Sweden)

    Alan Marshall

    2008-01-01

    Full Text Available Haptic information originates from a different human sense (touch, therefore the quality of service (QoS required to support haptic traffic is significantly different from that used to support conventional real-time traffic such as voice or video. Each type of network impairment has different (and severe impacts on the user's haptic experience. There has been no specific provision of QoS parameters for haptic interaction. Previous research into distributed haptic virtual environments (DHVEs have concentrated on synchronization of positions (haptic device or virtual objects, and are based on client-server architectures. We present a new peer-to-peer DHVE architecture that further extends this to enable force interactions between two users whereby force data are sent to the remote peer in addition to positional information. The work presented involves both simulation and practical experimentation where multimodal data is transmitted over a QoS-enabled IP network. Both forms of experiment produce consistent results which show that the use of specific QoS classes for haptic traffic will reduce network delay and jitter, leading to improvements in users' haptic experiences with these types of applications.

  11. Key Economic Parameters for an Optimal Pharmacy Network in a Regulated Environment

    Directory of Open Access Journals (Sweden)

    Franjo MLINARIC

    2016-10-01

    Full Text Available Pharmacies are an integral part of the modern healthcare system which strives for a holistic and effi cient care. General practitioners and pharmacists are held in high esteem among local communities as they are the fi rst point of contact when people have health issues. However, a strong demand for health services in developed countries and its present fi nancing schemes undermined the sustainability of the whole health system (8.9% of GDP in 2013 and growing. According to WHO and EU recommendations, the whole healthcare system shall accept a holistic approach and focus on education, prevention and proper medicine consume. Part of this strategy is a seamless care concept, where medical doctors and pharmacists build a team around the well-being of a patient. Financing scheme incentives and KPI’s (key performance indicators will be focused on keeping people healthy, instead of paying for procedures. The future healthcare ecosystem obliges pharmacists to optimize network coverage and to extend health services. Nevertheless, their growth strategy needs to be gradual, considering the present level of network coverage, the low pace of private and public expenditures for medicine and services, and the fact that a new fi nancing model for pharmacies is still unknown. Thus, we expect the development of pharmacy network in regulated environment to be fi nanced predominantly from retained earnings in publicly owned pharmacies and by awarding pharmacy concessions.

  12. DLTAP: A Network-efficient Scheduling Method for Distributed Deep Learning Workload in Containerized Cluster Environment

    Directory of Open Access Journals (Sweden)

    Qiao Wei

    2017-01-01

    Full Text Available Deep neural networks (DNNs have recently yielded strong results on a range of applications. Training these DNNs using a cluster of commodity machines is a promising approach since training is time consuming and compute-intensive. Furthermore, putting DNN tasks into containers of clusters would enable broader and easier deployment of DNN-based algorithms. Toward this end, this paper addresses the problem of scheduling DNN tasks in the containerized cluster environment. Efficiently scheduling data-parallel computation jobs like DNN over containerized clusters is critical for job performance, system throughput, and resource utilization. It becomes even more challenging with the complex workloads. We propose a scheduling method called Deep Learning Task Allocation Priority (DLTAP which performs scheduling decisions in a distributed manner, and each of scheduling decisions takes aggregation degree of parameter sever task and worker task into account, in particularly, to reduce cross-node network transmission traffic and, correspondingly, decrease the DNN training time. We evaluate the DLTAP scheduling method using a state-of-the-art distributed DNN training framework on 3 benchmarks. The results show that the proposed method can averagely reduce 12% cross-node network traffic, and decrease the DNN training time even with the cluster of low-end servers.

  13. RADAP II, an interim radar data processor

    Science.gov (United States)

    Greene, D. R.; Nilsen, J. D.; Saffle, R. E.; Holmes, D. W.; Hudlow, M. D.; Ahnert, P. R.

    The RADAP (radar data processor) II system, which is developed by the National Weather Service and is a follow-up of the D/RADEX (Digitized Radar Experiment) is described. RADAP maintains the present automatic digital processing capabilities at the D/RADEX sites and extends these capabilities to include 10 network sites in order to fulfill the digital radar data requirements during the period before the production of the Next-Generation Weather Radar (NEXRAD) systems. Consideration is given to the current and future users of the RADAP II data, to the system capability, operational requirements, and hardware; to the installation schedule, and to the products of RADAP II. RADAP II is used for the continued development and testing of applications software to provide feedback on the operational usefulness of the software which is critical to the successful design and development of the NEXRAD system.

  14. Hardware in the loop simulation of arbitrary magnitude shaped correlated radar clutter

    CSIR Research Space (South Africa)

    Strydom, JJ

    2014-10-01

    Full Text Available This paper describes a simple process for the generation of arbitrary probability distributions of complex data with correlation from sample to sample, optimized for hardware in the loop radar environment simulation. Measured radar clutter is used...

  15. Applicability of Doppler weather radar based rainfall data for runoff ...

    Indian Academy of Sciences (India)

    Radar-based hydrological studies in various countries have proven that computation of runoff using radar rainfall data could outperform rain gauge network measurements. There are no reported studies on their utilization for hydrological modelling and/or flood-related studies in Indian river basins. A comparison study ...

  16. Doppler weather radar based nowcasting of cyclone Ogni

    Indian Academy of Sciences (India)

    Disaster Management Support Project (DMSP). Processing of Indian Doppler Weather Radar. (DWR) data for nowcasting application under the sub-project Local Severe Storms and Flash. Floods was one component of this collaborative project. IMD has recently started upgrading its old ana- log radar network with a denser ...

  17. A Mobile Sensor Network to Map CO2 in Urban Environments

    Science.gov (United States)

    Lee, J.; Christen, A.; Nesic, Z.; Ketler, R.

    2014-12-01

    Globally, an estimated 80% of all fuel-based CO2 emissions into the atmosphere are attributable to cities, but there is still a lack of tools to map, visualize and monitor emissions to the scales at which emissions reduction strategies can be implemented - the local and urban scale. Mobile CO2 sensors, such as those attached to taxis and other existing mobile platforms, may be a promising way to observe and map CO2 mixing ratios across heterogenous urban environments with a limited number of sensors. Emerging modular open source technologies, and inexpensive compact sensor components not only enable rapid prototyping and replication, but also are allowing for the miniaturization and mobilization of traditionally fixed sensor networks. We aim to optimize the methods and technologies for monitoring CO2 in cities using a network of CO2 sensors deployable on vehicles and bikes. Our sensor technology is contained in a compact weather-proof case (35.8cm x 27.8cm x 11.8cm), powered independently by battery or by car, and includes the Li-Cor Li-820 infrared gas analyzer (Licor Inc, lincoln, NB, USA), Arduino Mega microcontroller (Arduino CC, Italy) and Adafruit GPS (Adafruit Technologies, NY, USA), and digital air temperature thermometer which measure CO2 mixing ratios (ppm), geolocation and speed, pressure and temperature, respectively at 1-second intervals. With the deployment of our sensor technology, we will determine if such a semi-autonomous mobile approach to monitoring CO2 in cities can determine excess urban CO2 mixing ratios (i.e. the 'urban CO2 dome') when compared to values measured at a fixed, remote background site. We present results from a pilot study in Vancouver, BC, where the a network of our new sensors was deployed both in fixed network and in a mobile campaign and examine the spatial biases of the two methods.

  18. Differential Recruitment of Brain Networks following Route and Cartographic Map Learning of Spatial Environments

    Science.gov (United States)

    Zhang, Hui; Copara, Milagros; Ekstrom, Arne D.

    2012-01-01

    An extensive neuroimaging literature has helped characterize the brain regions involved in navigating a spatial environment. Far less is known, however, about the brain networks involved when learning a spatial layout from a cartographic map. To compare the two means of acquiring a spatial representation, participants learned spatial environments either by directly navigating them or learning them from an aerial-view map. While undergoing functional magnetic resonance imaging (fMRI), participants then performed two different tasks to assess knowledge of the spatial environment: a scene and orientation dependent perceptual (SOP) pointing task and a judgment of relative direction (JRD) of landmarks pointing task. We found three brain regions showing significant effects of route vs. map learning during the two tasks. Parahippocampal and retrosplenial cortex showed greater activation following route compared to map learning during the JRD but not SOP task while inferior frontal gyrus showed greater activation following map compared to route learning during the SOP but not JRD task. We interpret our results to suggest that parahippocampal and retrosplenial cortex were involved in translating scene and orientation dependent coordinate information acquired during route learning to a landmark-referenced representation while inferior frontal gyrus played a role in converting primarily landmark-referenced coordinates acquired during map learning to a scene and orientation dependent coordinate system. Together, our results provide novel insight into the different brain networks underlying spatial representations formed during navigation vs. cartographic map learning and provide additional constraints on theoretical models of the neural basis of human spatial representation. PMID:23028661

  19. The modern research environment

    DEFF Research Database (Denmark)

    Topsøe, Flemming

    1993-01-01

    Information Technology, research environment, structured documents, networked information retrieval......Information Technology, research environment, structured documents, networked information retrieval...

  20. Networking of research information on global environment protection technologies; Chikyu kankyo taisaku gijutsu no kenkyu joho network jigyo

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    Networking is being executed with an objective of exchanging information on global environment technologies at an international level. In order to further promote the information exchange, and to make web sites user-friendly, fiscal 1998 has performed structuring a thesis renewal system. As a result of structuring the thesis renewal system, researchers can use the system as using a word processor by inputting data from a terminal in their laboratories. The data can also be made into a data base nearly semi-automatically. In addition to reducing time loss, delay and input errors because of re-entry, the researchers can make the data into a database on nearly a real time basis, and can provide their own theses to any part of the world through Internet. With regard to retaining Internet security, the security software having been introduced last year was renewed. In addition, detailed status such as daily access has become possible of identification as a result of introducing the net intellect. (NEDO)

  1. Understanding radar systems

    CERN Document Server

    Kingsley, Simon

    1999-01-01

    What is radar? What systems are currently in use? How do they work? This book provides engineers and scientists with answers to these critical questions, focusing on actual radar systems in use today. It is a perfect resource for those just entering the field, or as a quick refresher for experienced practitioners. The book leads readers through the specialized language and calculations that comprise the complex world of radar engineering as seen in dozens of state-of-the-art radar systems. An easy to read, wide ranging guide to the world of modern radar systems.

  2. Pulse Doppler radar

    CERN Document Server

    Alabaster, Clive

    2012-01-01

    This book is a practitioner's guide to all aspects of pulse Doppler radar. It concentrates on airborne military radar systems since they are the most used, most complex, and most interesting of the pulse Doppler radars; however, ground-based and non-military systems are also included. It covers the fundamental science, signal processing, hardware issues, systems design and case studies of typical systems. It will be a useful resource for engineers of all types (hardware, software and systems), academics, post-graduate students, scientists in radar and radar electronic warfare sectors and milit

  3. HF Radar Bistatic Measurement of Surface Current Velocities: Drifter Comparisons and Radar Consistency Checks

    OpenAIRE

    Lipa, Belinda; Whelan, Chad; Rector, Bill; Nyden, Bruce

    2009-01-01

    We describe the operation of a bistatic HF radar network and outline analysis methods for the derivation of the elliptical velocity components from the radar echo spectra. Bistatic operation is illustrated by application to a bistatic pair: Both remote systems receive backscattered echo, with one remote system in addition receiving bistatic echoes transmitted by the other. The pair produces elliptical velocity components in addition to two sets of radials. Results are compared with drifter me...

  4. A Novel Energy-Aware Distributed Clustering Algorithm for Heterogeneous Wireless Sensor Networks in the Mobile Environment

    Directory of Open Access Journals (Sweden)

    Ying Gao

    2015-12-01

    Full Text Available In order to prolong the network lifetime, energy-efficient protocols adapted to the features of wireless sensor networks should be used. This paper explores in depth the nature of heterogeneous wireless sensor networks, and finally proposes an algorithm to address the problem of finding an effective pathway for heterogeneous clustering energy. The proposed algorithm implements cluster head selection according to the degree of energy attenuation during the network’s running and the degree of candidate nodes’ effective coverage on the whole network, so as to obtain an even energy consumption over the whole network for the situation with high degree of coverage. Simulation results show that the proposed clustering protocol has better adaptability to heterogeneous environments than existing clustering algorithms in prolonging the network lifetime.

  5. Low-Cost Mini Radar: Design Prototyping and Tests

    Directory of Open Access Journals (Sweden)

    Dario Tarchi

    2017-01-01

    Full Text Available Radar systems are largely employed for surveillance of wide and remote areas; the recent advent of drones gives the opportunity to exploit radar sensors on board of unmanned aerial platforms. Nevertheless, whereas drone radars are currently available for military applications, their employment in the civilian domain is still limited. The present research focuses on design, prototyping, and testing of an agile, low-cost, mini radar system, to be carried on board of Remotely Piloted Aircraft (RPAs or tethered aerostats. In particular, the paper faces the challenge to integrate the in-house developed radar sensor with a low-cost navigation board, which is used to estimate attitude and positioning data. In fact, a suitable synchronization between radar and navigation data is essential to properly reconstruct the radar picture whenever the platform is moving or the radar is scanning different azimuthal sectors. Preliminary results, relative to tests conducted in preoperational conditions, are provided and exploited to assert the suitable consistency of the obtained radar pictures. From the results, there is a high consistency between the radar images and the picture of the current environment emerges; finally, the comparison of radar images obtained in different scans shows the stability of the platform.

  6. Coupling X-band dual-polarized mini-radars and hydro-meteorological forecast models: the HYDRORAD project

    Directory of Open Access Journals (Sweden)

    E. Picciotti

    2013-05-01

    Full Text Available Hydro-meteorological hazards like convective outbreaks leading to torrential rain and floods are among the most critical environmental issues world-wide. In that context weather radar observations have proven to be very useful in providing information on the spatial distribution of rainfall that can support early warning of floods. However, quantitative precipitation estimation by radar is subjected to many limitations and uncertainties. The use of dual-polarization at high frequency (i.e. X-band has proven particularly useful for mitigating some of the limitation of operational systems, by exploiting the benefit of easiness to transport and deploy and the high spatial and temporal resolution achievable at small antenna sizes. New developments on X-band dual-polarization technology in recent years have received the interest of scientific and operational communities in these systems. New enterprises are focusing on the advancement of cost-efficient mini-radar network technology, based on high-frequency (mainly X-band and low-power weather radar systems for weather monitoring and hydro-meteorological forecasting. Within the above context, the main objective of the HYDRORAD project was the development of an innovative mbox{integrated} decision support tool for weather monitoring and hydro-meteorological applications. The integrated system tool is based on a polarimetric X-band mini-radar network which is the core of the decision support tool, a novel radar products generator and a hydro-meteorological forecast modelling system that ingests mini-radar rainfall products to forecast precipitation and floods. The radar products generator includes algorithms for attenuation correction, hydrometeor classification, a vertical profile reflectivity correction, a new polarimetric rainfall estimators developed for mini-radar observations, and short-term nowcasting of convective cells. The hydro-meteorological modelling system includes the Mesoscale Model 5

  7. Coupling X-band dual-polarized mini-radars and hydro-meteorological forecast models: the HYDRORAD project

    Science.gov (United States)

    Picciotti, E.; Marzano, F. S.; Anagnostou, E. N.; Kalogiros, J.; Fessas, Y.; Volpi, A.; Cazac, V.; Pace, R.; Cinque, G.; Bernardini, L.; De Sanctis, K.; Di Fabio, S.; Montopoli, M.; Anagnostou, M. N.; Telleschi, A.; Dimitriou, E.; Stella, J.

    2013-05-01

    Hydro-meteorological hazards like convective outbreaks leading to torrential rain and floods are among the most critical environmental issues world-wide. In that context weather radar observations have proven to be very useful in providing information on the spatial distribution of rainfall that can support early warning of floods. However, quantitative precipitation estimation by radar is subjected to many limitations and uncertainties. The use of dual-polarization at high frequency (i.e. X-band) has proven particularly useful for mitigating some of the limitation of operational systems, by exploiting the benefit of easiness to transport and deploy and the high spatial and temporal resolution achievable at small antenna sizes. New developments on X-band dual-polarization technology in recent years have received the interest of scientific and operational communities in these systems. New enterprises are focusing on the advancement of cost-efficient mini-radar network technology, based on high-frequency (mainly X-band) and low-power weather radar systems for weather monitoring and hydro-meteorological forecasting. Within the above context, the main objective of the HYDRORAD project was the development of an innovative integrated decision support tool for weather monitoring and hydro-meteorological applications. The integrated system tool is based on a polarimetric X-band mini-radar network which is the core of the decision support tool, a novel radar products generator and a hydro-meteorological forecast modelling system that ingests mini-radar rainfall products to forecast precipitation and floods. The radar products generator includes algorithms for attenuation correction, hydrometeor classification, a vertical profile reflectivity correction, a new polarimetric rainfall estimators developed for mini-radar observations, and short-term nowcasting of convective cells. The hydro-meteorological modelling system includes the Mesoscale Model 5 (MM5) and the Army Corps

  8. Environment

    DEFF Research Database (Denmark)

    Valentini, Chiara

    2017-01-01

    The term environment refers to the internal and external context in which organizations operate. For some scholars, environment is defined as an arrangement of political, economic, social and cultural factors existing in a given context that have an impact on organizational processes and structures....... For others, environment is a generic term describing a large variety of stakeholders and how these interact and act upon organizations. Organizations and their environment are mutually interdependent and organizational communications are highly affected by the environment. This entry examines the origin...... and development of organization-environment interdependence, the nature of the concept of environment and its relevance for communication scholarships and activities....

  9. ULTRALIGHT RADAR FOR SMALL AND MICRO-UAV NAVIGATION

    OpenAIRE

    A. F. Scannapieco; A. Renga; Fasano, G.; A. Moccia

    2017-01-01

    This paper presents a radar approach to navigation of small and micro Unmanned Aerial Vehicles (UAV) in environments challenging for common sensors. A technique based on radar odometry is briefly explained and schemes for complete integration with other sensors are proposed. The focus of the paper is set on ultralight radars and interpretation of outputs of such sensor when dealing with autonomous navigation in complex scenario. The experimental setup used to analyse the proposed app...

  10. Deep Sea Shell Taphonomy: Interactive benthic experiments in hydrate environments of Barkley Canyon, Ocean Networks Canada.

    Science.gov (United States)

    Best, Mairi; Purser, Autun

    2015-04-01

    In order to quantify and track the rates and processes of modification of biogenic carbonate in gas hydrate environments, and their possible environmental/ecological correlates, ongoing observations of experimentally deployed specimens are being made using a remotely controlled crawler with camera and sensors. The crawler is connected to NEPTUNE Canada, an 800km, 5-node, regional cabled ocean network across the northern Juan de Fuca Plate, northeastern Pacific, part of Ocean Networks Canada. One of 15 study areas is an environment of exposed hydrate mounds along the wall of Barkley Canyon, at ˜865m water depth. This is the home of a benthic crawler developed by Jacobs University of Germany, who is affectionately known as Wally. Wally is equipped with a range of sensors including cameras, methane sensor, current meter, fluorometer, turbidity meter, CTD, and a sediment microprofiler with probes for oxygen, methane, sulphide, pH, temperature, and conductivity. In conjunction with this sensor suite, a series of experiments have been designed to assess the cycling of biogenic carbon and carbonate in this complex environment. The biota range from microbes, to molluscs, to large fish, and therefore the carbon inputs include both a range of organic carbon compounds as well as the complex materials that are "biogenic carbonate". Controlled experimental specimens were deployed of biogenic carbonate (Mytilus edulis fresh shells) and cellulose (pieces of untreated pine lumber) that had been previously well characterized (photographed, weighed, and numbered, matching valves and lumber kept as controls). Deployment at the sediment/water interface was in such a way to maximize natural burial exhumation cycles but to minimize specimen interaction. 10 replicate specimens of each material were deployed in two treatments: 1) adjacent to a natural life and death assemblage of chemosynthetic bivalves and exposed hydrate on a hydrate mound and 2) on the muddy seafloor at a distance

  11. Distributed optimization-based control of multi-agent networks in complex environments

    CERN Document Server

    Zhu, Minghui

    2015-01-01

    This book offers a concise and in-depth exposition of specific algorithmic solutions for distributed optimization based control of multi-agent networks and their performance analysis. It synthesizes and analyzes distributed strategies for three collaborative tasks: distributed cooperative optimization, mobile sensor deployment and multi-vehicle formation control. The book integrates miscellaneous ideas and tools from dynamic systems, control theory, graph theory, optimization, game theory and Markov chains to address the particular challenges introduced by such complexities in the environment as topological dynamics, environmental uncertainties, and potential cyber-attack by human adversaries. The book is written for first- or second-year graduate students in a variety of engineering disciplines, including control, robotics, decision-making, optimization and algorithms and with backgrounds in aerospace engineering, computer science, electrical engineering, mechanical engineering and operations research. Resea...

  12. Predicting trait-environment relationships for venation networks along an Andes-Amazon elevation gradient.

    Science.gov (United States)

    Blonder, Benjamin; Salinas, Norma; Patrick Bentley, Lisa; Shenkin, Alexander; Chambi Porroa, Percy O; Valdez Tejeira, Yolvi; Violle, Cyrille; Fyllas, Nikolaos M; Goldsmith, Gregory R; Martin, Robert E; Asner, Gregory P; Díaz, Sandra; Enquist, Brian J; Malhi, Yadvinder

    2017-05-01

    Understanding functional trait-environment relationships (TERs) may improve predictions of community assembly. However, many empirical TERs have been weak or lacking conceptual foundation. TERs based on leaf venation networks may better link individuals and communities via hydraulic constraints. We report measurements of vein density, vein radius, and leaf thickness for more than 100 dominant species occurring in ten forest communities spanning a 3,300 m Andes-Amazon elevation gradient in Peru. We use these data to measure the strength of TERs at community scale and to determine whether observed TERs are similar to those predicted by physiological theory. We found strong support for TERs between all traits and temperature, as well weaker support for a predicted TER between maximum abundance-weighted leaf transpiration rate and maximum potential evapotranspiration. These results provide one approach for developing a more mechanistic trait-based community assembly theory. © 2017 by the Ecological Society of America.

  13. Neural-Network-Based Smart Sensor Framework Operating in a Harsh Environment

    Directory of Open Access Journals (Sweden)

    Chaudhari Narendra S

    2005-01-01

    Full Text Available We present an artificial neural-network- (NN- based smart interface framework for sensors operating in harsh environments. The NN-based sensor can automatically compensate for the nonlinear response characteristics and its nonlinear dependency on the environmental parameters, with high accuracy. To show the potential of the proposed NN-based framework, we provide results of a smart capacitive pressure sensor (CPS operating in a wide temperature range of 0 to . Through simulated experiments, we have shown that the NN-based CPS model is capable of providing pressure readout with a maximum full-scale (FS error of only over this temperature range. A novel scheme for estimating the ambient temperature from the sensor characteristics itself is proposed. For this purpose, a second NN is utilized to estimate the ambient temperature accurately from the knowledge of the offset capacitance of the CPS. A microcontroller-unit- (MCU- based implementation scheme is also provided.

  14. SOCIAL NETWORK AS AN EFFECTIVE COMMUNICATION ENVIRONMENT BETWEEN TEACHER AND STUDENT IN EDUCATIONAL PROCESS

    Directory of Open Access Journals (Sweden)

    Nataliia M. Shulska

    2017-04-01

    Full Text Available Within the article the authors analyze the feasibility of using social network «Vkontakte» as an effective environment for teacher-student communication on the example of teaching discipline «Editorial craftsmanship» (2015-2016 academic year. It was investigated the communicative role of the teacher and students during teaching / mastering course using a community «Editorial craftsmanship». Based on results of the survey community members – students training direction «Publishing and Editing» Lesya Ukrainka Eastern European National University it was found that this form of organization of educational process in extracurricular time is effective for students. Proved that it extends the communication component, is convenient at performance of independent work on course, provides additional consultations, makes learning accessible, informal, interactive and creative.

  15. The Wireless Environment Monitoring Alarm System Based on Self-organizing Network

    Directory of Open Access Journals (Sweden)

    Zhang Huawei

    2016-01-01

    Full Text Available Under complicated conditions, it is necessary for environmental monitoring to design a wireless monitoring alarm system which can replace the wired system or as a supplement. The system discussed here bases on ARM7 microprocessor named LPC1114 and transceiver module named CC2530. With ZigBee, CSM/GPRS, this system uses multiple sensors to self-organized form a data acquisition and monitoring network system with variety of sensors fusion in the region. The system has some characteristics such as quick, convenient and accurate. Combining with the GSM SMS or GPRS alarm, the system can accurately and reliably monitor temperature, humidity and other environmental factors, and realize remote monitoring in large area and the complicated environment. Thus, this system has high practical value.

  16. Integrated multi-domain radar demonstration

    Science.gov (United States)

    Shilepsky, Carol C.; Bucknell, Mary; Taylor, Rick

    1991-12-01

    The objective of the IMRD program is to apply artificial intelligence techniques to the adaptive control of a state-of-the-art radar environment. The radar operates in the C-Band and is located within the Rome Laboratory Surveillance Facility (RLSF), Building 106, Griffiss Air Force Base (GAFB). The artificial intelligence is embedded in an adaptive control expert system which is written in Prolog. This system identifies sources of interference in each antenna beam position of the surveillance region and responds with the appropriate adaptive controls to maximize the probability of target detection consistent with operator-specified tactical objectives. In addition, the system has the following features: (1) radar inputs provided by a real, as opposed to a simulated, radar; (2) real-time operation with one scan response time of ten seconds or less; (3) modular design for rulebase and system evolution; (4) extensive parameterization for different radar configurations and operational specifications; and (5) control of a large number of radar parameters. The report includes IMRD organization, parameterization options for configuring it to different environments, the expert system software development, and results.

  17. Ground penetrating radar (GPR) analysis : Phase II field evaluation.

    Science.gov (United States)

    2011-10-01

    "The objective of this work was to evaluate the feasibility and value of expanding the MDT's Ground : Penetrating Radar (GPR) program to pavement design and rehabilitation, and to network level : evaluation. Phase I of this project concluded that in ...

  18. Validation of simulated hurricane drop size distributions using polarimetric radar

    National Research Council Canada - National Science Library

    Bonnie R Brown; Michael M Bell; Andrew J Frambach

    2016-01-01

      Recent upgrades to the U.S. radar network now allow for polarimetric measurements of landfalling hurricanes, providing a new data set to validate cloud microphysical parameterizations used in tropical cyclone simulations...

  19. Wireless Mid-Infrared Spectroscopy Sensor Network for Automatic Carbon Dioxide Fertilization in a Greenhouse Environment

    Directory of Open Access Journals (Sweden)

    Jianing Wang

    2016-11-01

    Full Text Available In this paper, a wireless mid-infrared spectroscopy sensor network was designed and implemented for carbon dioxide fertilization in a greenhouse environment. A mid-infrared carbon dioxide (CO2 sensor based on non-dispersive infrared (NDIR with the functionalities of wireless communication and anti-condensation prevention was realized as the sensor node. Smart transmission power regulation was applied in the wireless sensor network, according to the Received Signal Strength Indication (RSSI, to realize high communication stability and low-power consumption deployment. Besides real-time monitoring, this system also provides a CO2 control facility for manual and automatic control through a LabVIEW platform. According to simulations and field tests, the implemented sensor node has a satisfying anti-condensation ability and reliable measurement performance on CO2 concentrations ranging from 30 ppm to 5000 ppm. As an application, based on the Fuzzy proportional, integral, and derivative (PID algorithm realized on a LabVIEW platform, the CO2 concentration was regulated to some desired concentrations, such as 800 ppm and 1200 ppm, in 30 min with a controlled fluctuation of <±35 ppm in an acre of greenhouse.

  20. Wireless Mid-Infrared Spectroscopy Sensor Network for Automatic Carbon Dioxide Fertilization in a Greenhouse Environment.

    Science.gov (United States)

    Wang, Jianing; Niu, Xintao; Zheng, Lingjiao; Zheng, Chuantao; Wang, Yiding

    2016-11-18

    In this paper, a wireless mid-infrared spectroscopy sensor network was designed and implemented for carbon dioxide fertilization in a greenhouse environment. A mid-infrared carbon dioxide (CO₂) sensor based on non-dispersive infrared (NDIR) with the functionalities of wireless communication and anti-condensation prevention was realized as the sensor node. Smart transmission power regulation was applied in the wireless sensor network, according to the Received Signal Strength Indication (RSSI), to realize high communication stability and low-power consumption deployment. Besides real-time monitoring, this system also provides a CO₂ control facility for manual and automatic control through a LabVIEW platform. According to simulations and field tests, the implemented sensor node has a satisfying anti-condensation ability and reliable measurement performance on CO₂ concentrations ranging from 30 ppm to 5000 ppm. As an application, based on the Fuzzy proportional, integral, and derivative (PID) algorithm realized on a LabVIEW platform, the CO₂ concentration was regulated to some desired concentrations, such as 800 ppm and 1200 ppm, in 30 min with a controlled fluctuation of <±35 ppm in an acre of greenhouse.

  1. Simulation Model of Logistic Support to Isolated Airspace Smveillance Radar Stations

    OpenAIRE

    Tomislav Crnković; Ernest Bazijanac; Danko Basch

    2008-01-01

    A simulation model of the radar network operation of fivemilitary radar stations has been developed. Simulation waspeiformed in GPSS language and contains the time of operationof five radars through a period of one year, time of plannedpreventive maintenance, irregularities, time of corrective maintenanceand maintenance team(s). The simulation shows theinfluence of the number of maintenance teams on the availabilityof each radar and presents a good orienteering point fordefining the optimal m...

  2. Enhancement of environment and resources engineering studies through an international cooperation network

    Science.gov (United States)

    Caporali, E.; Tuneski, A.

    2012-12-01

    , following the criteria and conditions for setting up a Joint Postgraduate Degree. The new second cycle degree courses are going to be activated in the academic year 2012/2012. Both the first and second cycle curricula, developed through the co-operation, exchange of know-how and expertise between partners, are based on the European Credit Transfer System and are in accordance with the Bologna Process. In DEREL a second objective is to implement a sustainable regional network aimed to offer lifelong learning seminars for environment and resources engineering education and training of interested stakeholders and organize workshops focused on strengthening the links in the knowledge triangle: environment education-innovation-research, with participation of postgraduate students, public services, enterprises and NGO's. Also, the good collaborative environment created, since 2005, with the project partners can be surely mentioned as an additional valuable objective of the two TEMPUS projects, enabling implementation of a sustainable international network for environment and resources engineering studies enhancement and development.

  3. Influence of university network structures on forming the network environment of regional economy (on the example of national research universities of Tatarstan Republic

    Directory of Open Access Journals (Sweden)

    Darya-Anna Alekseevna Kaibiyainen

    2015-03-01

    Full Text Available Objective to elaborate theoretical and applied aspects of the processes of forming the new network institutional environment of the Russian regional economy under the influence of the developing integral educational network structures basing on the study of the experience of national research universities of Tatarstan Republic Methods general scientific logical methods of analysis and synthesis induction and deduction scientific abstraction as well as the method of systemicfunctional analysis. Results the practical examples are revealed and analyzed of introducing the new network integral principles into the functioning of national research universities which have a real economic effect and influencing such indicators of regional economy as the growth of employment reduction of unemployment etc. Scientific novelty problems of network structures development in the Russian education have not been thoroughly studied yet. The article analyzes the experience reveals and describes the methods and techniques of forming the network educational structures in the functioning of national research universities in Tatarstan Republic Practical value the author shows the ability of network university structures not only to play a significant role forming the new institutional environment of the regional economy but also to influence the macro and microeconomic indicators of development of the region and the country. nbsp

  4. Proceedings of the COST 75 final seminar on advanced weather radar systems; Beitraege des Instituts zum COST 75 final seminar on advanced weather radar systems

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, R.; Flender, F.; Hagen, M.; Hoeller, H.; Keil, C.; Meischner, P.

    1998-07-01

    Across Europe more than 110 weather radars are in operation. More than 60 of them are Doppler radars and this number is increasing steadily. Doppler systems are becoming an operational standard. Most systems operate in C-band, with the exception of the Spanish radar network which is composed of S-band Doppler radars. Radar product composites are available for Scandinavia and Central Europe. National networks exist for the UK, France and Spain. Europe further is fortunate to have 8 polarimetric Doppler radars used mainly for research. In Italy some of those systems are used also for operational nowcasting applications for dedicated customers. The Chilbolton multiparameter Doppler radar operates at S-band. (orig.)

  5. Experimental Performance Evaluation of Multihop IEEE 802.15.4/4g/4e Smart Utility Networks in Outdoor Environment

    Directory of Open Access Journals (Sweden)

    Chin-Sean Sum

    2017-01-01

    Full Text Available This paper presents the experimental performance evaluation results of the IEEE 802.15.4/4g/4e Smart Utility Networks (SUN in applications suited for outdoor environment. SUN is an advanced wireless communications network designed for reliable, low data rate, and low energy consumption networks for command-and-control applications like utility service, sensor network, and so on. IEEE 802.15.4g/4e is the international standard for SUN supported by multiple utility providers and product vendors. In this paper, a comprehensive field test was conducted by employing the implementation we have developed to evaluate the performance of the SUN devices based on IEEE 802.15.4/4g/4e standard. The output power of the implementation is 250 mW for extended range, reducible to 20 mW for short-range scalability and battery preservation. Results showed that in an outdoor line-of-sight environment, the achievable one-hop range of a 50 kbps SUN device was 450 m. Next, in a non-line-of-sight environment involving typical residential concrete building, the communications could be established penetrating obstructions to reach above the 11th storey, reaching the performance degradation limits at the 20th storey. Next, the network of the SUN system was proven to be capable of supporting a typical multihop tree network in a dense populated building, meeting the required performance by the standard.

  6. Proton transfer reactions and hydrogen-bond networks in protein environments.

    Science.gov (United States)

    Ishikita, Hiroshi; Saito, Keisuke

    2014-02-06

    In protein environments, proton transfer reactions occur along polar or charged residues and isolated water molecules. These species consist of H-bond networks that serve as proton transfer pathways; therefore, thorough understanding of H-bond energetics is essential when investigating proton transfer reactions in protein environments. When the pKa values (or proton affinity) of the H-bond donor and acceptor moieties are equal, significantly short, symmetric H-bonds can be formed between the two, and proton transfer reactions can occur in an efficient manner. However, such short, symmetric H-bonds are not necessarily stable when they are situated near the protein bulk surface, because the condition of matching pKa values is opposite to that required for the formation of strong salt bridges, which play a key role in protein-protein interactions. To satisfy the pKa matching condition and allow for proton transfer reactions, proteins often adjust the pKa via electron transfer reactions or H-bond pattern changes. In particular, when a symmetric H-bond is formed near the protein bulk surface as a result of one of these phenomena, its instability often results in breakage, leading to large changes in protein conformation.

  7. Network environ perspective for urban metabolism and carbon emissions: a case study of Vienna, Austria.

    Science.gov (United States)

    Chen, Shaoqing; Chen, Bin

    2012-04-17

    Cities are considered major contributors to global warming, where carbon emissions are highly embedded in the overall urban metabolism. To examine urban metabolic processes and emission trajectories we developed a carbon flux model based on Network Environ Analysis (NEA). The mutual interactions and control situation within the urban ecosystem of Vienna were examined, and the system-level properties of the city's carbon metabolism were assessed. Regulatory strategies to minimize carbon emissions were identified through the tracking of the possible pathways that affect these emission trajectories. Our findings suggest that indirect flows have a strong bearing on the mutual and control relationships between urban sectors. The metabolism of a city is considered self-mutualistic and sustainable only when the local and distal environments are embraced. Energy production and construction were found to be two factors with a major impact on carbon emissions, and whose regulation is only effective via ad-hoc pathways. In comparison with the original life-cycle tracking, the application of NEA was better at revealing details from a mechanistic aspect, which is crucial for informed sustainable urban management.

  8. Fault Diagnosis and Detection in Industrial Motor Network Environment Using Knowledge-Level Modelling Technique

    Directory of Open Access Journals (Sweden)

    Saud Altaf

    2017-01-01

    Full Text Available In this paper, broken rotor bar (BRB fault is investigated by utilizing the Motor Current Signature Analysis (MCSA method. In industrial environment, induction motor is very symmetrical, and it may have obvious electrical signal components at different fault frequencies due to their manufacturing errors, inappropriate motor installation, and other influencing factors. The misalignment experiments revealed that improper motor installation could lead to an unexpected frequency peak, which will affect the motor fault diagnosis process. Furthermore, manufacturing and operating noisy environment could also disturb the motor fault diagnosis process. This paper presents efficient supervised Artificial Neural Network (ANN learning technique that is able to identify fault type when situation of diagnosis is uncertain. Significant features are taken out from the electric current which are based on the different frequency points and associated amplitude values with fault type. The simulation results showed that the proposed technique was able to diagnose the target fault type. The ANN architecture worked well with selecting of significant number of feature data sets. It seemed that, to the results, accuracy in fault detection with features vector has been achieved through classification performance and confusion error percentage is acceptable between healthy and faulty condition of motor.

  9. Construction of high-dimensional neural network potentials using environment-dependent atom pairs.

    Science.gov (United States)

    Jose, K V Jovan; Artrith, Nongnuch; Behler, Jörg

    2012-05-21

    An accurate determination of the potential energy is the crucial step in computer simulations of chemical processes, but using electronic structure methods on-the-fly in molecular dynamics (MD) is computationally too demanding for many systems. Constructing more efficient interatomic potentials becomes intricate with increasing dimensionality of the potential-energy surface (PES), and for numerous systems the accuracy that can be achieved is still not satisfying and far from the reliability of first-principles calculations. Feed-forward neural networks (NNs) have a very flexible functional form, and in recent years they have been shown to be an accurate tool to construct efficient PESs. High-dimensional NN potentials based on environment-dependent atomic energy contributions have been presented for a number of materials. Still, these potentials may be improved by a more detailed structural description, e.g., in form of atom pairs, which directly reflect the atomic interactions and take the chemical environment into account. We present an implementation of an NN method based on atom pairs, and its accuracy and performance are compared to the atom-based NN approach using two very different systems, the methanol molecule and metallic copper. We find that both types of NN potentials provide an excellent description of both PESs, with the pair-based method yielding a slightly higher accuracy making it a competitive alternative for addressing complex systems in MD simulations.

  10. Construction of high-dimensional neural network potentials using environment-dependent atom pairs

    Science.gov (United States)

    Jose, K. V. Jovan; Artrith, Nongnuch; Behler, Jörg

    2012-05-01

    An accurate determination of the potential energy is the crucial step in computer simulations of chemical processes, but using electronic structure methods on-the-fly in molecular dynamics (MD) is computationally too demanding for many systems. Constructing more efficient interatomic potentials becomes intricate with increasing dimensionality of the potential-energy surface (PES), and for numerous systems the accuracy that can be achieved is still not satisfying and far from the reliability of first-principles calculations. Feed-forward neural networks (NNs) have a very flexible functional form, and in recent years they have been shown to be an accurate tool to construct efficient PESs. High-dimensional NN potentials based on environment-dependent atomic energy contributions have been presented for a number of materials. Still, these potentials may be improved by a more detailed structural description, e.g., in form of atom pairs, which directly reflect the atomic interactions and take the chemical environment into account. We present an implementation of an NN method based on atom pairs, and its accuracy and performance are compared to the atom-based NN approach using two very different systems, the methanol molecule and metallic copper. We find that both types of NN potentials provide an excellent description of both PESs, with the pair-based method yielding a slightly higher accuracy making it a competitive alternative for addressing complex systems in MD simulations.

  11. Phased-array radar design application of radar fundamentals

    CERN Document Server

    Jeffrey, Thomas

    2009-01-01

    Phased-Array Radar Design is a text-reference designed for electrical engineering graduate students in colleges and universities as well as for corporate in-house training programs for radar design engineers, especially systems engineers and analysts who would like to gain hands-on, practical knowledge and skills in radar design fundamentals, advanced radar concepts, trade-offs for radar design and radar performance analysis.

  12. Performance in wireless networks and industrial wireless networks on control processes in real time under industrial environments

    Directory of Open Access Journals (Sweden)

    Juan F. Monsalve-Posada

    2015-01-01

    Full Text Available The growing use of Ethernet networks on the industrial automation pyramid has led many companies to develop new devices to operate in requirements of this level, nowadays it is called Industrial Ethernet network, on the market there are various sensors and actuators to industrial scale equipped with this technology, many of these devices are very expensive. In this paper, the performance of two wireless networks is evaluated, the first network has conventional Ethernet devices, and the second network has Industrial Ethernet devices. For the process we vary four parameters such as distance, number of bytes, the signal to noise ratio, and the packet error rate, and then we measure delays and compare with metric statistics results, Box Plot graphs were used for the analysis. Finally, we conclude that under the parameters and conditions tested, wireless networks can serve as a communication system in control applications with allowable delays of up to 50 ms, in addition, the results show a better performance of Industrial Ethernet networks over conventional networks, with differences in the RTT of milliseconds. Therefore, it is recommended to establish what risk is for the process to control these delays to determine if the equipment conventional applies, since under certain features like humidity and temperature can operate properly for a considerable time and at lower cost than devices to Industrial Ethernet.

  13. Doppler radar physiological sensing

    CERN Document Server

    Lubecke, Victor M; Droitcour, Amy D; Park, Byung-Kwon; Singh, Aditya

    2016-01-01

    Presents a comprehensive description of the theory and practical implementation of Doppler radar-based physiological monitoring. This book includes an overview of current physiological monitoring techniques and explains the fundamental technology used in remote non-contact monitoring methods. Basic radio wave propagation and radar principles are introduced along with the fundamentals of physiological motion and measurement. Specific design and implementation considerations for physiological monitoring radar systems are then discussed in detail. The authors address current research and commercial development of Doppler radar based physiological monitoring for healthcare and other applications.

  14. CARPET: Een computerprogramma voor het analyseren van radars

    NARCIS (Netherlands)

    Huizing, A.G.

    1995-01-01

    CARPET is a user friendly computer program that can alleviate the difficult task of analysing the performance of surface-based radar systems. Empirical and theoretical models of the radar and its interaction with the environment are used to calculate the detection performance as a function of the

  15. Analysis of Radio Wave Propagation for ISM 2.4 GHz Wireless Sensor Networks in Inhomogeneous Vegetation Environments

    Science.gov (United States)

    Azpilicueta, Leire; López-Iturri, Peio; Aguirre, Erik; Mateo, Ignacio; Astrain, José Javier; Villadangos, Jesús; Falcone, Francisco

    2014-01-01

    The use of wireless networks has experienced exponential growth due to the improvements in terms of battery life and low consumption of the devices. However, it is compulsory to conduct previous radio propagation analysis when deploying a wireless sensor network. These studies are necessary to perform an estimation of the range coverage, in order to optimize the distance between devices in an actual network deployment. In this work, the radio channel characterization for ISM 2.4 GHz Wireless Sensor Networks (WSNs) in an inhomogeneous vegetation environment has been analyzed. This analysis allows designing environment monitoring tools based on ZigBee and WiFi where WSN and smartphones cooperate, providing rich and customized monitoring information to users in a friendly manner. The impact of topology as well as morphology of the environment is assessed by means of an in-house developed 3D Ray Launching code, to emulate the realistic operation in the framework of the scenario. Experimental results gathered from a measurement campaign conducted by deploying a ZigBee Wireless Sensor Network, are analyzed and compared with simulations in this paper. The scenario where this network is intended to operate is a combination of buildings and diverse vegetation species. To gain insight in the effects of radio propagation, a simplified vegetation model has been developed, considering the material parameters and simplified geometry embedded in the simulation scenario. An initial location-based application has been implemented in a real scenario, to test the functionality within a context aware scenario. The use of deterministic tools can aid to know the impact of the topological influence in the deployment of the optimal Wireless Sensor Network in terms of capacity, coverage and energy consumption, making the use of these systems attractive for multiple applications in inhomogeneous vegetation environments. PMID:25513820

  16. Analysis of radio wave propagation for ISM 2.4 GHz Wireless Sensor Networks in inhomogeneous vegetation environments.

    Science.gov (United States)

    Azpilicueta, Leire; López-Iturri, Peio; Aguirre, Erik; Mateo, Ignacio; Astrain, José Javier; Villadangos, Jesús; Falcone, Francisco

    2014-12-10

    The use of wireless networks has experienced exponential growth due to the improvements in terms of battery life and low consumption of the devices. However, it is compulsory to conduct previous radio propagation analysis when deploying a wireless sensor network. These studies are necessary to perform an estimation of the range coverage, in order to optimize the distance between devices in an actual network deployment. In this work, the radio channel characterization for ISM 2.4 GHz Wireless Sensor Networks (WSNs) in an inhomogeneous vegetation environment has been analyzed. This analysis allows designing environment monitoring tools based on ZigBee and WiFi where WSN and smartphones cooperate, providing rich and customized monitoring information to users in a friendly manner. The impact of topology as well as morphology of the environment is assessed by means of an in-house developed 3D Ray Launching code, to emulate the realistic operation in the framework of the scenario. Experimental results gathered from a measurement campaign conducted by deploying a ZigBee Wireless Sensor Network, are analyzed and compared with simulations in this paper. The scenario where this network is intended to operate is a combination of buildings and diverse vegetation species. To gain insight in the effects of radio propagation, a simplified vegetation model has been developed, considering the material parameters and simplified geometry embedded in the simulation scenario. An initial location-based application has been implemented in a real scenario, to test the functionality within a context aware scenario. The use of deterministic tools can aid to know the impact of the topological influence in the deployment of the optimal Wireless Sensor Network in terms of capacity, coverage and energy consumption, making the use of these systems attractive for multiple applications in inhomogeneous vegetation environments.

  17. Analysis of Radio Wave Propagation for ISM 2.4 GHz Wireless Sensor Networks in Inhomogeneous Vegetation Environments

    Directory of Open Access Journals (Sweden)

    Leire Azpilicueta

    2014-12-01

    Full Text Available The use of wireless networks has experienced exponential growth due to the improvements in terms of battery life and low consumption of the devices. However, it is compulsory to conduct previous radio propagation analysis when deploying a wireless sensor network. These studies are necessary to perform an estimation of the range coverage, in order to optimize the distance between devices in an actual network deployment. In this work, the radio channel characterization for ISM 2.4 GHz Wireless Sensor Networks (WSNs in an inhomogeneous vegetation environment has been analyzed. This analysis allows designing environment monitoring tools based on ZigBee and WiFi where WSN and smartphones cooperate, providing rich and customized monitoring information to users in a friendly manner. The impact of topology as well as morphology of the environment is assessed by means of an in-house developed 3D Ray Launching code, to emulate the realistic operation in the framework of the scenario. Experimental results gathered from a measurement campaign conducted by deploying a ZigBee Wireless Sensor Network, are analyzed and compared with simulations in this paper. The scenario where this network is intended to operate is a combination of buildings and diverse vegetation species. To gain insight in the effects of radio propagation, a simplified vegetation model has been developed, considering the material parameters and simplified geometry embedded in the simulation scenario. An initial location-based application has been implemented in a real scenario, to test the functionality within a context aware scenario. The use of deterministic tools can aid to know the impact of the topological influence in the deployment of the optimal Wireless Sensor Network in terms of capacity, coverage and energy consumption, making the use of these systems attractive for multiple applications in inhomogeneous vegetation environments.

  18. Radar Plan Position Indicator Scope

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Radar Plan Position Indicator Scope is the collection of weather radar imagery for the period prior to the beginning of the Next Generation Radar (NEXRAD) system...

  19. Design of Detection Engine for Wormhole Attack in Adhoc Network Environment

    OpenAIRE

    Husain Shahnawaz; Joshi R.C; Gupta S.C.

    2012-01-01

    Adhoc network is a collection of nodes that are capable to form dynamically atemporary network without the support of any centralized fixed infrastructure. There is no central controller to determine the reliable & secure communication paths in Mobile Adhoc network. Each node in the Adhoc network has to rely on each other in order to forward packets, thus highly cooperative nodes are required to ensure that the initiated data transmission process does not fail. In a mobile Adhoc network (MANE...

  20. Ultralight Radar for Small and Micro-Uav Navigation

    Science.gov (United States)

    Scannapieco, A. F.; Renga, A.; Fasano, G.; Moccia, A.

    2017-08-01

    This paper presents a radar approach to navigation of small and micro Unmanned Aerial Vehicles (UAV) in environments challenging for common sensors. A technique based on radar odometry is briefly explained and schemes for complete integration with other sensors are proposed. The focus of the paper is set on ultralight radars and interpretation of outputs of such sensor when dealing with autonomous navigation in complex scenario. The experimental setup used to analyse the proposed approach comprises one multi-rotor UAV and one ultralight commercial radar. Results from flight tests in which both forward-only motion and mixed motion are presented and analysed, providing a reference for understanding outputs of radar in complex scenarios. The radar odometry solution is compared with ground truth provided by GPS sensor.

  1. ULTRALIGHT RADAR FOR SMALL AND MICRO-UAV NAVIGATION

    Directory of Open Access Journals (Sweden)

    A. F. Scannapieco

    2017-08-01

    Full Text Available This paper presents a radar approach to navigation of small and micro Unmanned Aerial Vehicles (UAV in environments challenging for common sensors. A technique based on radar odometry is briefly explained and schemes for complete integration with other sensors are proposed. The focus of the paper is set on ultralight radars and interpretation of outputs of such sensor when dealing with autonomous navigation in complex scenario. The experimental setup used to analyse the proposed approach comprises one multi-rotor UAV and one ultralight commercial radar. Results from flight tests in which both forward-only motion and mixed motion are presented and analysed, providing a reference for understanding outputs of radar in complex scenarios. The radar odometry solution is compared with ground truth provided by GPS sensor.

  2. Combined radar and telemetry system

    Energy Technology Data Exchange (ETDEWEB)

    Rodenbeck, Christopher T.; Young, Derek; Chou, Tina; Hsieh, Lung-Hwa; Conover, Kurt; Heintzleman, Richard

    2017-08-01

    A combined radar and telemetry system is described. The combined radar and telemetry system includes a processing unit that executes instructions, where the instructions define a radar waveform and a telemetry waveform. The processor outputs a digital baseband signal based upon the instructions, where the digital baseband signal is based upon the radar waveform and the telemetry waveform. A radar and telemetry circuit transmits, simultaneously, a radar signal and telemetry signal based upon the digital baseband signal.

  3. Radar based autonomous sensor module

    Science.gov (United States)

    Styles, Tim

    2016-10-01

    Most surveillance systems combine camera sensors with other detection sensors that trigger an alert to a human operator when an object is detected. The detection sensors typically require careful installation and configuration for each application and there is a significant burden on the operator to react to each alert by viewing camera video feeds. A demonstration system known as Sensing for Asset Protection with Integrated Electronic Networked Technology (SAPIENT) has been developed to address these issues using Autonomous Sensor Modules (ASM) and a central High Level Decision Making Module (HLDMM) that can fuse the detections from multiple sensors. This paper describes the 24 GHz radar based ASM, which provides an all-weather, low power and license exempt solution to the problem of wide area surveillance. The radar module autonomously configures itself in response to tasks provided by the HLDMM, steering the transmit beam and setting range resolution and power levels for optimum performance. The results show the detection and classification performance for pedestrians and vehicles in an area of interest, which can be modified by the HLDMM without physical adjustment. The module uses range-Doppler processing for reliable detection of moving objects and combines Radar Cross Section and micro-Doppler characteristics for object classification. Objects are classified as pedestrian or vehicle, with vehicle sub classes based on size. Detections are reported only if the object is detected in a task coverage area and it is classified as an object of interest. The system was shown in a perimeter protection scenario using multiple radar ASMs, laser scanners, thermal cameras and visible band cameras. This combination of sensors enabled the HLDMM to generate reliable alerts with improved discrimination of objects and behaviours of interest.

  4. Health Status and Social Networks as Predictors of Resilience in Older Adults Residing in Rural and Remote Environments

    Directory of Open Access Journals (Sweden)

    Christine McKibbin

    2016-01-01

    Full Text Available Purpose. Health status and social networks are associated with resilience among older adults. Each of these factors may be important to the ability of adults to remain in rural and remote communities as they age. We examined the association of health status and social networks and resilience among older adults dwelling in a rural and remote county in the Western United States. Methods. We selected a random sample of 198 registered voters aged 65 years or older from a frontier Wyoming county. Hierarchical linear regression was used to examine the association of health status as well as social networks and resilience. We also examined health status as a moderator of the relationship between social networks and resilience. Results. Family networks (p=0.024 and mental health status (p<0.001 significantly predicted resilience. Mental health status moderated the relationship of family (p=0.004 and friend (p=0.021 networks with resilience. Smaller family and friend networks were associated with greater resilience when mental health status was low, but not when it was high. Conclusion. Efforts to increase mental health status may improve resilience among older adults in rural environments, particularly for those with smaller family and friends networks.

  5. Maritime target and sea clutter measurements with a coherent Doppler polarimetric surveillance radar

    NARCIS (Netherlands)

    Smith, A.J.E.; Gelsema, S.J.; Kester, L.J.H.M.; Melief, H.W.; Premel Cabic, G.; Theil, A.; Woudenberg, E.

    2002-01-01

    Doppler polarimetry in a surveillance radar for the maritime surface picture is considered. This radar must be able to detect low-RCS targets in littoral environments. Measurements on such targets have been conducted with a coherent polarimetric measurement radar in March 2001 and preliminary

  6. Digital Earth Watch And Picture Post Network: Measuring The Environment Through Digital Images

    Science.gov (United States)

    Schloss, A. L.; Beaudry, J.; Carrera, F.; Pickle, J.

    2010-12-01

    Digital Earth Watch (DEW) involves individuals, schools, organizations and communities in a systematic monitoring project of their local environment, especially vegetation health. The program offers people the means to join the Picture Post network and to study and analyze their own findings using DEW software. A Picture Post is an easy-to-use and inexpensive platform for repeatedly taking digital photographs as a standardized set of images of the entire 360 ° landscape, which then can be shared over the Internet on the Picture Post website. This simple concept has the potential to create a wealth of information and data on changing environmental conditions, which is important for a society grappling with the effects of environmental change. Picture Post participants study change over time in their local area, compare digital images with NASA satellite imagery and contribute towards improving their own communities. A key message in DEW is that although plants are dynamic and respond continuously to their environment, they do so either on a time-scale that most people don't notice or with a subtlety our senses can't detect. DEW has created simple tools for monitoring vegetation as a means towards understanding the connection between global climate change and local effects. Picture Posts may be added by anyone interested in monitoring a particular location. The value of a Picture Post is in the commitment of participants to take repeated photographs - monthly, weekly, or even daily - to build up a long-term record over many years. DEW is being developed by a collaborative effort led by the University of New Hampshire with the Federation of Earth Science Information Partners, the University of Southern Maine, and Worcester Polytechnic Institute. This poster will show examples of picture posts and data that can be collected and will describe our soon-to-be-released “ virtual ” picture post cell phone app. The Picture Post network is new and we invite individuals

  7. Extended QoS modelling based on multi-application environment in network on chip

    Science.gov (United States)

    Saadaoui, Abdelkader; Nasri, Salem

    2015-01-01

    Until now, there is no standard method of the quality of service (QoS) measurement and fewer techniques have been used to provide its definition. Therefore, researchers are looking for a projection of QoS on quantifiable space, since it is qualitative, subjective and not measurable. However, a few tentatives have studied QoS parameter estimation. Many applications in network on chip (NoC) present variable QoS parameters such as packet loss rate (PLR), end-to-end delay (EED) and throughput (Thp). However, there are a few papers that have developed different methods to modelise QoS in NoC. Their QoS presentation does not provide a multi-application parameter arbiter. Independently of the approach used, an important challenge associated with QoS provision is the development of an efficient and flexible way to monitor QoS. The originality of our approach is based on a proposition of a QoS-intellectual property module in NoC architecture to improve network performances. We implement an extended approach of QoS metrics modelling for NoC on multi-parameter and multi-application environment. The QoS metrics model is based on QoS parameters such as PLR, EED and Thp for different applications. To validate this work, a dynamic routing simulation for 4 × 4 mesh NoC behaviour under three different applications, namely transmission control protocol, variable bit rate and constant bit rate, is considered. To achieve an ideal network behaviour, load balancing on NoC with multiple concurrent applications is improved using QoS metrics measurement based on dynamic routing. The results have shown that extended QoS modelling approach is easy and cheap to implement in hardware-software quantifiable representation. Thus, implementing a quantifiable representation of QoS can be used to provide a NoC services arbiter. QoS arbiter interacts with other routers to ensure flit flow and QoS modelling to provide a QoS value.

  8. A Comparative Study on Cooperative Learning in Multimedia and Network Environment Used by English Majors between China Mainland and Taiwan

    Science.gov (United States)

    Xue, Gong; Lingling, Liu

    2018-01-01

    This paper first based on the theory of cooperative learning research. It analyses the characteristics and advantages of cooperative learning under the multimedia network environment. And then take China Three Gorges University and Taiwan I-Shou University English major students for example, using questionnaires and interviews to investigate the…

  9. Using Social Networking Environments to Support Collaborative Learning in a Chinese University Class: Interaction Pattern and Influencing Factors

    Science.gov (United States)

    Lu, Jie; Churchill, Daniel

    2014-01-01

    This paper reports a study that investigated the social interaction pattern of collaborative learning and the factors affecting the effectiveness of collaborative learning in a social networking environment (SNE). A class of 55 undergraduate students enrolled in an elective course at a Chinese university was recruited for the study. The…

  10. Cross-Cultural Collisions in Cyberspace: Case Studies of International Legal Issues for Educators Working in Globally Networked Learning Environments

    Science.gov (United States)

    Rife, Martine Courant

    2010-01-01

    This article explores some of the legal and law-related challenges educators face in designing, implementing, and sustaining globally networked learning environments (GNLEs) in the context of conflicting international laws on intellectual property and censorship/free speech. By discussing cases and areas involving such legal issues, the article…

  11. Principals' Perceptions of Social Networking Access, Its Relationship to Cyberbullying, the Importance of Student Achievement, and the School Environment

    Science.gov (United States)

    Townsel, Andrae

    2015-01-01

    The purpose of this study was to examine the principals' perceptions of social networking access and its relationship to cyberbullying, the importance of student achievement, and the school environment across the United States. This research provides some evidence on how principals perceive and understand the threat of cyberbullying and its…

  12. Exploiting Deep Neural Networks and Head Movements for Robust Binaural Localization of Multiple Sources in Reverberant Environments

    DEFF Research Database (Denmark)

    Ma, Ning; May, Tobias; Brown, Guy J.

    2017-01-01

    This paper presents a novel machine-hearing system that exploits deep neural networks (DNNs) and head movements for robust binaural localization of multiple sources in reverberant environments. DNNs are used to learn the relationship between the source azimuth and binaural cues, consisting...

  13. Feasibility of a Networked Air Traffic Infrastructure Validation Environment for Advanced NextGen Concepts

    Science.gov (United States)

    McCormack, Michael J.; Gibson, Alec K.; Dennis, Noah E.; Underwood, Matthew C.; Miller,Lana B.; Ballin, Mark G.

    2013-01-01

    Abstract-Next Generation Air Transportation System (NextGen) applications reliant upon aircraft data links such as Automatic Dependent Surveillance-Broadcast (ADS-B) offer a sweeping modernization of the National Airspace System (NAS), but the aviation stakeholder community has not yet established a positive business case for equipage and message content standards remain in flux. It is necessary to transition promising Air Traffic Management (ATM) Concepts of Operations (ConOps) from simulation environments to full-scale flight tests in order to validate user benefits and solidify message standards. However, flight tests are prohibitively expensive and message standards for Commercial-off-the-Shelf (COTS) systems cannot support many advanced ConOps. It is therefore proposed to simulate future aircraft surveillance and communications equipage and employ an existing commercial data link to exchange data during dedicated flight tests. This capability, referred to as the Networked Air Traffic Infrastructure Validation Environment (NATIVE), would emulate aircraft data links such as ADS-B using in-flight Internet and easily-installed test equipment. By utilizing low-cost equipment that is easy to install and certify for testing, advanced ATM ConOps can be validated, message content standards can be solidified, and new standards can be established through full-scale flight trials without necessary or expensive equipage or extensive flight test preparation. This paper presents results of a feasibility study of the NATIVE concept. To determine requirements, six NATIVE design configurations were developed for two NASA ConOps that rely on ADS-B. The performance characteristics of three existing in-flight Internet services were investigated to determine whether performance is adequate to support the concept. Next, a study of requisite hardware and software was conducted to examine whether and how the NATIVE concept might be realized. Finally, to determine a business case

  14. Radar illusion via metamaterials

    Science.gov (United States)

    Jiang, Wei Xiang; Cui, Tie Jun

    2011-02-01

    An optical illusion is an image of a real target perceived by the eye that is deceptive or misleading due to a physiological illusion or a specific visual trick. The recently developed metamaterials provide efficient approaches to generate a perfect optical illusion. However, all existing research on metamaterial illusions has been limited to theory and numerical simulations. Here, we propose the concept of a radar illusion, which can make the electromagnetic (EM) image of a target gathered by radar look like a different target, and we realize a radar illusion device experimentally to change the radar image of a metallic target into a dielectric target with predesigned size and material parameters. It is well known that the radar signatures of metallic and dielectric objects are significantly different. However, when a metallic target is enclosed by the proposed illusion device, its EM scattering characteristics will be identical to that of a predesigned dielectric object under the illumination of radar waves. Such an illusion device will confuse the radar, and hence the real EM properties of the metallic target cannot be perceived. We designed and fabricated the radar illusion device using artificial metamaterials in the microwave frequency, and good illusion performances are observed in the experimental results.

  15. Aspects of Radar Polarimetry

    OpenAIRE

    Lüneburg, Ernst

    2002-01-01

    This contribution is a tutorial introduction to the phenomenological theory of radar polarimetry for the coherent scatter case emphasizing monostatic backscattering and forward scattering (transmission). Characteristic similarities and differences between radar polarimetry and optical polarimetry and the role of linear and antilinear operators (time-reversal) are pointed out and typical polarimetric invariants are identified.

  16. Determination of radar MTF

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, D. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    The ultimate goal of the Current Meter Array (CMA) is to be able to compare the current patterns detected with the array with radar images of the water surface. The internal wave current patterns modulate the waves on the water surface giving a detectable modulation of the radar cross-section (RCS). The function relating the RCS modulations to the current patterns is the Modulation Transfer Function (MTF). By comparing radar images directly with co-located CMA measurements the MTF can be determined. In this talk radar images and CMA measurements from a recent experiment at Loch Linnhe, Scotland, will be used to make the first direct determination of MTF for an X and S band radar at low grazing angles. The technical problems associated with comparing radar images to CMA data will be explained and the solution method discussed. The results suggest the both current and strain rate contribute equally to the radar modulation for X band. For S band, the strain rate contributes more than the current. The magnitude of the MTF and the RCS modulations are consistent with previous estimates when the wind is blowing perpendicular to the radar look direction.

  17. Decoders for MST radars

    Science.gov (United States)

    Woodman, R. F.

    1983-01-01

    Decoding techniques and equipment used by MST radars are described and some recommendations for new systems are presented. Decoding can be done either by software in special-purpose (array processors, etc.) or general-purpose computers or in specially designed digital decoders. Both software and hardware decoders are discussed and the special case of decoding for bistatic radars is examined.

  18. Java Radar Analysis Tool

    Science.gov (United States)

    Zaczek, Mariusz P.

    2005-01-01

    Java Radar Analysis Tool (JRAT) is a computer program for analyzing two-dimensional (2D) scatter plots derived from radar returns showing pieces of the disintegrating Space Shuttle Columbia. JRAT can also be applied to similar plots representing radar returns showing aviation accidents, and to scatter plots in general. The 2D scatter plots include overhead map views and side altitude views. The superposition of points in these views makes searching difficult. JRAT enables three-dimensional (3D) viewing: by use of a mouse and keyboard, the user can rotate to any desired viewing angle. The 3D view can include overlaid trajectories and search footprints to enhance situational awareness in searching for pieces. JRAT also enables playback: time-tagged radar-return data can be displayed in time order and an animated 3D model can be moved through the scene to show the locations of the Columbia (or other vehicle) at the times of the corresponding radar events. The combination of overlays and playback enables the user to correlate a radar return with a position of the vehicle to determine whether the return is valid. JRAT can optionally filter single radar returns, enabling the user to selectively hide or highlight a desired radar return.

  19. Development of Radar Control system for Multi-mode Active Phased Array Radar for atmospheric probing

    Science.gov (United States)

    Yasodha, Polisetti; Jayaraman, Achuthan; Thriveni, A.

    2016-07-01

    TR modules, (ii) radar operation software which facilitates experimental parameter setting and operating the radar in different modes, (iii) beam steering software which computes the amplitude co-efficients and phases required for each TR module, for forming the beams selected for radar operation with the desired shape and (iv) Calibration software for calibrating the radar by measuring the differential insertion phase and amplitudes in all 1024 Transmit and Receive paths and correcting them. The TR module configuring software is a major task as it needs to control 1024 TR modules, which are located in the field about 150 m away from the RC system in the control room. Each TR module has a processor identified with a dedicated IP address, along with memory to store the instructions and parameters required for radar operation. A communication link is designed using Gigabit Ethernet (GbE) switches to realise 1 to 1024 way switching network. RC system computer communicates with the each processor using its IP address and establishes connection, via 1 to 1024 port GbE switching network. The experimental parameters data are pre-loaded parallely into all the TR modules along with the phase shifter data required for beam steering using this network. A reference timing pulse is sent to all the TR modules simultaneously, which indicates the start of radar operation. RC system also monitors the status parameters from the TR modules indicating their health during radar operation at regular intervals, via GbE switching network. Beam steering software generates the phase shift required for each TR module for the beams selected for operation. Radar operational software calls the phase shift data required for beam steering and adds it to the calibration phase obtained through calibration software and loads the resultant phase data into TR modules. Timed command/data transfer to/from subsystems and synchronisation of subsystems is essential for proper real-time operation of the

  20. Digital Earth Watch And Picture Post Network: Measuring The Environment Through Digital Images

    Science.gov (United States)

    Schloss, A. L.; Beaudry, J.; Pickle, J.; Carrera, F.

    2012-12-01

    Digital Earth Watch (DEW) involves individuals, schools, organizations and communities in a systematic monitoring project of their local environment, especially vegetation health. The program offers people the means to join the Picture Post network and to study and analyze their own findings using DEW software. A Picture Post is an easy-to-use and inexpensive platform for repeatedly taking digital photographs as a standardized set of images of the entire 360° landscape, which then can be shared over the Internet on the Picture Post website. This simple concept has the potential to create a wealth of information and data on changing environmental conditions, which is important for a society grappling with the effects of environmental change. Picture Posts may be added by anyone interested in monitoring a particular location. The value of a Picture Post is in the commitment of participants to take repeated photographs - monthly, weekly, or even daily - to build up a long-term record over many years. This poster will show examples of Picture Post pictures being used for monitoring and research applications, and a DEW mobile app for capturing repeat digital photographs at a virtual post. We invite individuals, schools, informal education centers, groups and communities to join.; A new post and its website. ; Creating a virtual post using the mobile app.

  1. A novel neural network-based technique for smart gas sensors operating in a dynamic environment.

    Science.gov (United States)

    Baha, Hakim; Dibi, Zohir

    2009-01-01

    Thanks to their high sensitivity and low-cost, metal oxide gas sensors (MOX) are widely used in gas detection, although they present well-known problems (lack of selectivity and environmental effects…). We present in this paper a novel neural network- based technique to remedy these problems. The idea is to create intelligent models; the first one, called corrector, can automatically linearize a sensor's response characteristics and eliminate its dependency on the environmental parameters. The corrector's responses are processed with the second intelligent model which has the role of discriminating exactly the detected gas (nature and concentration). The gas sensors used are industrial resistive kind (TGS8xx, by Figaro Engineering). The MATLAB environment is used during the design phase and optimization. The sensor models, the corrector, and the selective model were implemented and tested in the PSPICE simulator. The sensor model accurately expresses the nonlinear character of the response and the dependence on temperature and relative humidity in addition to their gas nature dependency. The corrector linearizes and compensates the sensor's responses. The method discriminates qualitatively and quantitatively between seven gases. The advantage of the method is that it uses a small representative database so we can easily implement the model in an electrical simulator. This method can be extended to other sensors.

  2. Trust-Based Access Control Model from Sociological Approach in Dynamic Online Social Network Environment

    Science.gov (United States)

    Kim, Seungjoo

    2014-01-01

    There has been an explosive increase in the population of the OSN (online social network) in recent years. The OSN provides users with many opportunities to communicate among friends and family. Further, it facilitates developing new relationships with previously unknown people having similar beliefs or interests. However, the OSN can expose users to adverse effects such as privacy breaches, the disclosing of uncontrolled material, and the disseminating of false information. Traditional access control models such as MAC, DAC, and RBAC are applied to the OSN to address these problems. However, these models are not suitable for the dynamic OSN environment because user behavior in the OSN is unpredictable and static access control imposes a burden on the users to change the access control rules individually. We propose a dynamic trust-based access control for the OSN to address the problems of the traditional static access control. Moreover, we provide novel criteria to evaluate trust factors such as sociological approach and evaluate a method to calculate the dynamic trust values. The proposed method can monitor negative behavior and modify access permission levels dynamically to prevent the indiscriminate disclosure of information. PMID:25374943

  3. Wireless Propagation Characteristics for Vehicular Ad–Hoc Networks in Motorway Environments

    Directory of Open Access Journals (Sweden)

    A. Edwards

    2009-10-01

    Full Text Available This paper presents the measurements and analytical results regarding important characteristics of wireless propagation for vehicular ad–hoc networks in motorway environments, including Doppler Effect, Free Space Signal propagation, path loss and system operating margin. In this work, we employ IEEE 802.1 1b wireless cards for inter–vehicular communication to analyze large and small–scale propagation models. According to large–scale models, the maximum distance between the transmitter and receiver vehicle is 446 m using 5 dBi omni–directional antennas. Additionally, the feasible System Operating Margin (SOM of 446 m is greater than 13 dB, which is over the minimum margin recommended. Our results show that the Doppler Effect does not affect the transmission between communication partners at high speeds in small–scale models. Finally, we realize an experiment to validate the results in the worst case scenario, when the transmitter and receiver vehicle are traveling in opposing directions on a straightaway. Results show that at least 8 packets can be relayed when the transmitter and receiver antennas are mountedonautomobile dashboards.

  4. Trust-Based Access Control Model from Sociological Approach in Dynamic Online Social Network Environment

    Directory of Open Access Journals (Sweden)

    Seungsoo Baek

    2014-01-01

    Full Text Available There has been an explosive increase in the population of the OSN (online social network in recent years. The OSN provides users with many opportunities to communicate among friends and family. Further, it facilitates developing new relationships with previously unknown people having similar beliefs or interests. However, the OSN can expose users to adverse effects such as privacy breaches, the disclosing of uncontrolled material, and the disseminating of false information. Traditional access control models such as MAC, DAC, and RBAC are applied to the OSN to address these problems. However, these models are not suitable for the dynamic OSN environment because user behavior in the OSN is unpredictable and static access control imposes a burden on the users to change the access control rules individually. We propose a dynamic trust-based access control for the OSN to address the problems of the traditional static access control. Moreover, we provide novel criteria to evaluate trust factors such as sociological approach and evaluate a method to calculate the dynamic trust values. The proposed method can monitor negative behavior and modify access permission levels dynamically to prevent the indiscriminate disclosure of information.

  5. Students' Adoption of Social Networks as Environments for Learning and Teaching: The Case of the Facebook

    Directory of Open Access Journals (Sweden)

    Wajeeh M. Daher

    2014-06-01

    Full Text Available Little is known about the conditions and consequences of using the Facebook in learning. This research attempts to describe such conditions and consequences when teachers experiment using it as students in a second degree course. Fifteen students/teachers aged from 24 to 53 years old participated in the course in which they were required to attend mathematical Facebook sites. The research findings arrived at using the grounded theory show that the conditions which affected the teachers/students' work in the Facebook were: (1 causal conditions: the course's requirement; (2 intervening conditions: the participant's image of the Facebook, the participant's work characteristics and the participant's competence in computers and the internet; (3 contextual conditions: The site's subject and the environment's characteristics or conditions. These conditions influenced students' learning actions and interactions in the Facebook, especially their level of participation. The actions/interactions of the participants, together with the various conditions influenced the consequences of students' educational work in the social networking site. These consequences varied, starting from discovering how to utilize the Facebook for teaching and being aware of the advantages/ disadvantages of doing so, to proceeding with the use of the Facebook in contexts other than those being suggested in the course.

  6. A Novel Neural Network-Based Technique for Smart Gas Sensors Operating in a Dynamic Environment

    Directory of Open Access Journals (Sweden)

    Zohir Dibi

    2009-11-01

    Full Text Available Thanks to their high sensitivity and low-cost, metal oxide gas sensors (MOX are widely used in gas detection, although they present well-known problems (lack of selectivity and environmental effects…. We present in this paper a novel neural network- based technique to remedy these problems. The idea is to create intelligent models; the first one, called corrector, can automatically linearize a sensor’s response characteristics and eliminate its dependency on the environmental parameters. The corrector’s responses are processed with the second intelligent model which has the role of discriminating exactly the detected gas (nature and concentration. The gas sensors used are industrial resistive kind (TGS8xx, by Figaro Engineering. The MATLAB environment is used during the design phase and optimization. The sensor models, the corrector, and the selective model were implemented and tested in the PSPICE simulator. The sensor model accurately expresses the nonlinear character of the response and the dependence on temperature and relative humidity in addition to their gas nature dependency. The corrector linearizes and compensates the sensor’s responses. The method discriminates qualitatively and quantitatively between seven gases. The advantage of the method is that it uses a small representative database so we can easily implement the model in an electrical simulator. This method can be extended to other sensors.

  7. Micropower impulse radar imaging

    Energy Technology Data Exchange (ETDEWEB)

    Hall, M.S.

    1995-11-01

    From designs developed at the Lawrence Livermore National Laboratory (LLNL) in radar and imaging technologies, there exists the potential for a variety of applications in both public and private sectors. Presently tests are being conducted for the detection of buried mines and the analysis of civil structures. These new systems use a patented ultra-wide band (impulse) radar technology known as Micropower Impulse Radar (GPR) imaging systems. LLNL has also developed signal processing software capable of producing 2-D and 3-D images of objects embedded in materials such as soil, wood and concrete. My assignment while at LLNL has focused on the testing of different radar configurations and applications, as well as assisting in the creation of computer algorithms which enable the radar to scan target areas of different geometeries.

  8. Rain radar measurement error estimation using data assimilation in an advection-based nowcasting system

    Science.gov (United States)

    Merker, Claire; Ament, Felix; Clemens, Marco

    2017-04-01

    The quantification of measurement uncertainty for rain radar data remains challenging. Radar reflectivity measurements are affected, amongst other things, by calibration errors, noise, blocking and clutter, and attenuation. Their combined impact on measurement accuracy is difficult to quantify due to incomplete process understanding and complex interdependencies. An improved quality assessment of rain radar measurements is of interest for applications both in meteorology and hydrology, for example for precipitation ensemble generation, rainfall runoff simulations, or in data assimilation for numerical weather prediction. Especially a detailed description of the spatial and temporal structure of errors is beneficial in order to make best use of the areal precipitation information provided by radars. Radar precipitation ensembles are one promising approach to represent spatially variable radar measurement errors. We present a method combining ensemble radar precipitation nowcasting with data assimilation to estimate radar measurement uncertainty at each pixel. This combination of ensemble forecast and observation yields a consistent spatial and temporal evolution of the radar error field. We use an advection-based nowcasting method to generate an ensemble reflectivity forecast from initial data of a rain radar network. Subsequently, reflectivity data from single radars is assimilated into the forecast using the Local Ensemble Transform Kalman Filter. The spread of the resulting analysis ensemble provides a flow-dependent, spatially and temporally correlated reflectivity error estimate at each pixel. We will present first case studies that illustrate the method using data from a high-resolution X-band radar network.

  9. System architecture for ubiquitous live video streaming in university network environment

    CSIR Research Space (South Africa)

    Dludla, AG

    2013-09-01

    Full Text Available The recent growth of ubiquitous computing brings to the networking discipline new classes of home, campus, and mobile networks. This would enable education service providers to provide services to learners anywhere, anytime and not only through...

  10. Static and dynamic calibration of radar data for hydrological use

    Directory of Open Access Journals (Sweden)

    S. J. Wood

    2000-01-01

    Full Text Available The HYREX dense raingauge network over the Brue catchment in Somerset, England is used to explore the accuracy of calibrated (raingauge-adjusted weather radar data. Calibration is restricted to the use of any single gauge within the catchment so as to simulate the conditions in a typical rainfall monitoring network. Combination of a single gauge and a radar estimate is used to obtain calibrated radar estimates, with the 'calibration factor' varying dynamically from one time-frame to the next. Comparing this dynamic calibration with a static (long-term calibration factor indicates the distance from a gauge over which the dynamic calibration is useful. A tapered calibration factor is implemented which behaves in the same way as the raw dynamic calibration at short distances, tending towards the static calibration factor at larger distances. This hybrid approach outperforms raingauge, uncalibrated radar, and statically-calibrated radar estimates of rainfall for the majority of raingauges in the catchment. The results provide valuable guidance on the density of raingauge network to employ in combination with a weather radar for flood estimation and forecasting. Keywords: radar, raingauge, calibration, rainfall, accuracy

  11. Embedded Active Fiber Optic Sensing Network for Structural Health Monitoring in Harsh Environments

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Anbo [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

    2016-09-30

    This report summarizes technical progress on the program “Embedded Active Fiber Optic Sensing Network for Structural Health Monitoring in Harsh Environments” funded by the National Energy Technology Laboratory of the U.S. Department of Energy, and performed by the Center for Photonics Technology at Virginia Tech. The objective of this project is to develop a first-of-a-kind technology for remote fiber optic generation and detection of acoustic waves for structural health monitoring in harsh environments. During the project period, which is from April 1, 2013 to Septemeber 30, 2016, three different acoustic generation mechanisms were studied in detail for their applications in building a fiber optic acoustic generation unit (AGU), including laser induced plasma breakdown (LIP), Erbium-doped fiber laser absorption, and metal laser absorption. By comparing the performance of the AGUs designed based on these three mechanisms and analyzing the experimental results with simulations, the metal laser absorption method was selected to build a complete fiber optic structure health monitoring (FO-SHM) system for the proposed high temperature multi-parameter structure health monitoring application. Based on the simulation of elastic wave propagation and fiber Bragg grating acoustic pulse detection, an FO-SHM element together with a completed interrogation system were designed and built. This system was first tested on an aluminum piece in the low-temperature range and successfully demonstrated its capability of multi-parameter monitoring and multi-point sensing. In the later stages of the project, the research was focused on improving the surface attachment design and preparing the FO-SHM element for high temperature environment tests. After several upgrades to the surface attachment methods, the FO-SHM element was able to work reliably up to 600oC when attached to P91 pipes, which are the target material of this project. In the final stage of this project, this FO

  12. Principles of modern radar radar applications

    CERN Document Server

    Scheer, James A

    2013-01-01

    Principles of Modern Radar: Radar Applications is the third of the three-volume seriesof what was originally designed to be accomplished in one volume. As the final volumeof the set, it finishes the original vision of a complete yet bounded reference for radartechnology. This volume describes fifteen different system applications or class ofapplications in more detail than can be found in Volumes I or II.As different as the applications described, there is a difference in how these topicsare treated by the authors. Whereas in Volumes I and II there is strict adherence tochapter format and leve

  13. Extracting bird migration information from C-band Doppler weather radars

    NARCIS (Netherlands)

    van Gasteren, H.; Holleman, I.; Bouten, W.; van Loon, E.; Shamoun-Baranes, J.

    2008-01-01

    Although radar has been used in studies of bird migration for 60 years, there is still no network in Europe for comprehensive monitoring of bird migration. Europe has a dense network of military air surveillance radars but most systems are not directly suitable for reliable bird monitoring. Since

  14. QoS Parameters Evaluation in a VPN-MPLS Diffserv Network under a Complete Free Software Emulation Environment

    Directory of Open Access Journals (Sweden)

    Miroslava Aracely Zapata Rodríguez

    2017-12-01

    Full Text Available The use of Virtual Private Network – Multi Protocol Label Switching (VPN-MPLS networks has become very common inside enterprises thanks to their multiple advantages; such as, the private communication across a public network infrastructure between geographically diverse sites. This leads to a need for an efficient network in terms of Quality of Service (QoS to guarantee reliability and security of information. However, the implementation of a VPN-MPLS network is neither easy nor cheap for small and medium companies; hence, in most cases, it is required the use of emulators that are not free either. In this paper, we analyze a VPN-MPLS network in terms of QoS metrics: delay, jitter and packet loss. This evaluation was performed in a virtual environment using only free software tools under two test scenarios, with and without Differentiated Services (DiffServ. The results showed that a VPN-MPLS DiffServ network reduces the delay by approximately 96.78% in VoIP, 39.21% in Data and 66.83% in Streaming; furthermore, the jitter was reduced by approximately 27.88% in VoIP and 41.09% in Data.

  15. Using TRMM and GPM precipitation radar for calibration of weather radars in the Philippines

    Science.gov (United States)

    Crisologo, Irene; Bookhagen, Bodo; Smith, Taylor; Heistermann, Maik

    2016-04-01

    Torrential and sustained rainfall from tropical cyclones, monsoons, and thunderstorms frequently impact the Philippines. In order to predict, assess, and measure storm impact, it is imperative to have a reliable and accurate monitoring system in place. In 2011, the Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) established a weather radar network of ten radar devices, eight of which are single-polarization S-band radars and two dual-polarization C-band radars. Because of a low-density hydrometeorological monitoring networks in the Philippines, calibration of weather radars becomes a challenging, but important task. In this study, we explore the potential of scrutinizing the calibration of ground radars by using the observations from the Tropical Rainfall Measuring Mission (TRMM). For this purpose, we compare different TRMM level 1 and 2 orbital products from overpasses over the Philippines, and compare these products to reflectivities observed by the Philippine ground radars. Differences in spatial resolution are addressed by computing adequate zonal statistics of the local radar bins located within the corresponding TRMM cell in space and time. The wradlib package (Heistermann et al. 2013; Heistermann et al. 2015) is used to process the data from the Subic S-band single-polarization weather radar. These data will be analyzed in conjunction with TRMM data for June to August 2012, three months of the wet season. This period includes the enhanced monsoon of 2012, locally called Habagat 2012, which brought sustained intense rainfall and massive floods in several parts of the country including the most populated city of Metro Manila. References Heistermann, M., Jacobi, S., Pfaff, T. (2013): Technical Note: An open source library for processing weather radar data (wradlib). Hydrol. Earth Syst. Sci., 17, 863-871, doi: 10.5194/hess-17-863-2013. Heistermann, M., S. Collis, M. J. Dixon, S. Giangrande, J. J. Helmus, B. Kelley, J

  16. Social Network Analysis in E-Learning Environments: A Preliminary Systematic Review

    Science.gov (United States)

    Cela, Karina L.; Sicilia, Miguel Ángel; Sánchez, Salvador

    2015-01-01

    E-learning occupies an increasingly prominent place in education. It provides the learner with a rich virtual network where he or she can exchange ideas and information and create synergies through interactions with other members of the network, whether fellow learners or teachers. Social network analysis (SNA) has proven extremely powerful at…

  17. Assimilation of radar quantitative precipitation estimations in the Canadian Precipitation Analysis (CaPA)

    Science.gov (United States)

    Fortin, Vincent; Roy, Guy; Donaldson, Norman; Mahidjiba, Ahmed

    2015-12-01

    The Canadian Precipitation Analysis (CaPA) is a data analysis system used operationally at the Canadian Meteorological Center (CMC) since April 2011 to produce gridded 6-h and 24-h precipitation accumulations in near real-time on a regular grid covering all of North America. The current resolution of the product is 10-km. Due to the low density of the observational network in most of Canada, the system relies on a background field provided by the Regional Deterministic Prediction System (RDPS) of Environment Canada, which is a short-term weather forecasting system for North America. For this reason, the North American configuration of CaPA is known as the Regional Deterministic Precipitation Analysis (RDPA). Early in the development of the CaPA system, weather radar reflectivity was identified as a very promising additional data source for the precipitation analysis, but necessary quality control procedures and bias-correction algorithms were lacking for the radar data. After three years of development and testing, a new version of CaPA-RDPA system was implemented in November 2014 at CMC. This version is able to assimilate radar quantitative precipitation estimates (QPEs) from all 31 operational Canadian weather radars. The radar QPE is used as an observation source and not as a background field, and is subject to a strict quality control procedure, like any other observation source. The November 2014 upgrade to CaPA-RDPA was implemented at the same time as an upgrade to the RDPS system, which brought minor changes to the skill and bias of CaPA-RDPA. This paper uses the frequency bias indicator (FBI), the equitable threat score (ETS) and the departure from the partial mean (DPM) in order to assess the improvements to CaPA-RDPA brought by the assimilation of radar QPE. Verification focuses on the 6-h accumulations, and is done against a network of 65 synoptic stations (approximately two stations per radar) that were withheld from the station data assimilated by Ca

  18. Chaotic synchronization of nearest-neighbor diffusive coupling Hindmarsh-Rose neural networks in noisy environments

    Energy Technology Data Exchange (ETDEWEB)

    Fang Xiaoling [Institute of Mechanobiology and Medical Engineering, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, P.O. Box 888, 800 Dongchuan Road, Minhang, Shanghai 200240 (China); Yu Hongjie [Department of Engineering Mechanics, Shanghai Jiao Tong University, Shanghai 200240 (China); Jiang Zonglai [Institute of Mechanobiology and Medical Engineering, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, P.O. Box 888, 800 Dongchuan Road, Minhang, Shanghai 200240 (China)], E-mail: zljiang@sjtu.edu.cn

    2009-03-15

    The chaotic synchronization of Hindmarsh-Rose neural networks linked by a nonlinear coupling function is discussed. The HR neural networks with nearest-neighbor diffusive coupling form are treated as numerical examples. By the construction of a special nonlinear-coupled term, the chaotic system is coupled symmetrically. For three and four neurons network, a certain region of coupling strength corresponding to full synchronization is given, and the effect of network structure and noise position are analyzed. For five and more neurons network, the full synchronization is very difficult to realize. All the results have been proved by the calculation of the maximum conditional Lyapunov exponent.

  19. The development of deep learning in synthetic aperture radar imagery

    CSIR Research Space (South Africa)

    Schwegmann, Colin P

    2017-05-01

    Full Text Available The usage of remote sensing to observe environments necessitates interdisciplinary approaches to derive effective, impactful research. One remote sensing technique, Synthetic Aperture Radar, has shown significant benefits over traditional remote...

  20. Radar cross section

    CERN Document Server

    Knott, Gene; Tuley, Michael

    2004-01-01

    This is the second edition of the first and foremost book on this subject for self-study, training, and course work. Radar cross section (RCS) is a comparison of two radar signal strengths. One is the strength of the radar beam sweeping over a target, the other is the strength of the reflected echo sensed by the receiver. This book shows how the RCS ?gauge? can be predicted for theoretical objects and how it can be measured for real targets. Predicting RCS is not easy, even for simple objects like spheres or cylinders, but this book explains the two ?exact? forms of theory so well that even a

  1. Radar and electronic navigation

    CERN Document Server

    Sonnenberg, G J

    2013-01-01

    Radar and Electronic Navigation, Sixth Edition discusses radar in marine navigation, underwater navigational aids, direction finding, the Decca navigator system, and the Omega system. The book also describes the Loran system for position fixing, the navy navigation satellite system, and the global positioning system (GPS). It reviews the principles, operation, presentations, specifications, and uses of radar. It also describes GPS, a real time position-fixing system in three dimensions (longitude, latitude, altitude), plus velocity information with Universal Time Coordinated (UTC). It is accur

  2. Two-role model of an interaction network of free-living γ-proteobacteria from an oligotrophic environment.

    Science.gov (United States)

    Aguirre-von-Wobeser, Eneas; Soberón-Chávez, Gloria; Eguiarte, Luis E; Ponce-Soto, Gabriel Yaxal; Vázquez-Rosas-Landa, Mirna; Souza, Valeria

    2014-05-01

    Antagonistic interactions are frequently observed among bacteria in the environment and result in complex networks, which could promote co-existence, and therefore promote biodiversity. We analysed interactions of aquatic bacteria isolated by their ability to grow in Pseudomonas isolation agar from Churince, Cuatro Ciénegas, Mexico. In the resulting network, highly antagonistic and highly sensitive strains could be distinguished, forming a largely hierarchical structure. Most of the highly antagonistic strains belonged to the genus Pseudomonas. The network was sender-determined, which means that the antagonist strains had a larger influence on its structure than the sensitive ones. Very few interactions were necessary to connect all strains, implying that the network was 'small world'. The network was highly nested, having a core of highly interacting strains, with which the less antagonistic or highly sensitive interact. A probabilistic model was built, which captured most features of the network. Biological interpretation of the model implied a state in which many different antagonistic mechanisms were present, and most strains were resistant to them. Our work shows that strains of Pseudomonas from the water column at Cuatro Ciénegas have the potential to interact antagonistically with many closely related strains and that these interactions are usually not reciprocal. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

  3. Network Computer Technology. Phase I: Viability and Promise within NASA's Desktop Computing Environment

    Science.gov (United States)

    Paluzzi, Peter; Miller, Rosalind; Kurihara, West; Eskey, Megan

    1998-01-01

    Over the past several months, major industry vendors have made a business case for the network computer as a win-win solution toward lowering total cost of ownership. This report provides results from Phase I of the Ames Research Center network computer evaluation project. It identifies factors to be considered for determining cost of ownership; further, it examines where, when, and how network computer technology might fit in NASA's desktop computing architecture.

  4. Digital journalism in the Network Society: innovating in a competitive environment

    OpenAIRE

    José-Alberto García-Avilés

    2017-01-01

    Internet’s rise as a dominant medium has transformed the ecosystem of the Network Society, bringing about deep changes in the economy, politics, culture, leisure and the public sphere (Castells, 1997). As a result, millions of communicators are connected to a Network increasingly intertwined, reaching global dimensions. Network communication pushes the limits and breaks frontiers: any isolated incident might originate international consequences, such as we have seen with Fidel Castro’s death,...

  5. CERN Document Server: Document Management System for Grey Literature in Networked Environment

    OpenAIRE

    Vesely, Martin; Baron, Thomas; Le Meur, Jean-Yves; Simko, Tibor; GreyNet, Grey Literature Network Service

    2003-01-01

    In this paper we present a technology for networked information services, developed at the CERN Document Server (CDS) research group, called the CERN Document Server Software (CDSware). Standardization of networked information services in the field of grey literature has recently become a subject of an intensive research in the digital library community. The current state-of-the-art in this area effectively allows to provide various networked information services, such as information brokerin...

  6. Stochastic Prediction and Feedback Control of Router Queue Size in a Virtual Network Environment

    Science.gov (United States)

    2014-09-18

    OPNET model of the simple queuing system had used [3]. Client ServerRouter Figure 3.8: 1 router network topology 3.4.1.2 2 Routers Network...traffic demand with the inclusion of real operating systems and applications versus application models provided by discrete-event modeling and...2.1 Network Queues The mathematical study of queues or waiting lines is referred to as queuing theory. It consist of models constructed with the aim

  7. Report on the survey in fiscal 1998. Survey on an environment technology transfer information network; 1998 nendo hokokusho. Kankyo gijutsu iten joho network chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    This paper describes a survey on an environment technology transfer information network. Based on the achievements obtained by the surveys in fiscal 1995 and 1996, the ICETT has participated as one organization constituting the APEC environment technology exchange virtual center, and begun providing information since April 1997. As the environment technology information, those items actually employed by factories and operation sites in Japan are put into a data base, and into a home page including training information centering around those contained in the data base, and examples of works done by local governments for prevention of pollution. Furthermore in fiscal 1997, a simulation software for a model process has been developed. Fiscal 1998 strengthened the data base for environment preservation technology information, investigated environment preserving model companies and summarized them including even their management aspect. Investigations were carried out in developing countries on application of cleaner technologies. Gaps far exceeding anticipation exist in every field between these developing countries and Japan. Environment protection measures applied and succeeded in the developing countries as the means to narrow the gaps were collected, and compiled as the specific examples. (NEDO)

  8. A genetic algorithm solution for the operation of green LTE networks with energy and environment considerations

    KAUST Repository

    Ghazzai, Hakim

    2012-01-01

    The Base Station (BS) sleeping strategy has become a well-known technique to achieve energy savings in cellular networks by switching off redundant BSs mainly for lightly loaded networks. Besides, the exploitation of renewable energies, as additional power sources in smart grids, becomes a real challenge to network operators to reduce power costs. In this paper, we propose a method based on genetic algorithms that decreases the energy consumption of a Long-Term Evolution (LTE) cellular network by not only shutting down underutilized BSs but also by optimizing the amounts of energy procured from the smart grid without affecting the desired Quality of Service. © 2012 Springer-Verlag.

  9. Detecting 1/10th scaled structures in dielectric media using monostatic X-band radar scattering measurements

    Science.gov (United States)

    Kekis, John D.; Testorf, Markus E.; Fiddy, Michael A.; Giles, Robert H.

    2000-11-01

    Under the sponsorship of the U.S. Army's National Ground Intelligence Center (NGIC), researchers at U. Mass. Lowell's Submillimeter-Wave Technology Laboratory (STL) and Center for Electromagnetic Materials and Optical Systems (CEMOS) investigated the feasibility of detecting non-metallic structures embedded in various types of soil using a 1-GHz ground penetrating radar by establishing a 1/10th-scale laboratory environment with two spot-focusing X-band (10- GHz) lens antennae and an HP8510B Network Analyzer. Achieving similitude with the full-scale environment required fabricating replicas that were dimensional and dielectric scale-models of the non-metallic structures of interest (i.e. anti-personnel mines), as well as rocks, and soil with various levels of moisture content. The 1/10th- scale replicas were constructed form models at 10.0-GHz. The monostatic X-band measurements were acquired in an anechoic environment, and digital images of the backscattered radar data from the 1/10th-scale composite scenes were processed using inverse synthetic aperture radar (ISAR) signal processing routines, and also PDFT superresolution imaging techniques. Based on the 1/10th-scale signature measurements performed, the feasibility of detecting a VS-50 anti-personnel mine buried in dry loam at a depth of 11.2mm was established. The full-scale radar cross-section of a VS=50 mine in this configuration was estimated to be -25 dBsm. Radar cross section values were not established for the structures embedded in the wet loam due to a change in the intensity scale (an inherent property of the superresolution algorithm), which changed for each image. However, the embedded objects were detected by the PDFT algorithm, showing promise for the future of this research.

  10. Spatial variability of extreme rainfall at radar subpixel scale

    Science.gov (United States)

    Peleg, Nadav; Marra, Francesco; Fatichi, Simone; Paschalis, Athanasios; Molnar, Peter; Burlando, Paolo

    2018-01-01

    Extreme rainfall is quantified in engineering practice using Intensity-Duration-Frequency curves (IDF) that are traditionally derived from rain-gauges and more recently also from remote sensing instruments, such as weather radars. These instruments measure rainfall at different spatial scales: rain-gauge samples rainfall at the point scale while weather radar averages precipitation on a relatively large area, generally around 1 km2. As such, a radar derived IDF curve is representative of the mean areal rainfall over a given radar pixel and neglects the within-pixel rainfall variability. In this study, we quantify subpixel variability of extreme rainfall by using a novel space-time rainfall generator (STREAP model) that downscales in space the rainfall within a given radar pixel. The study was conducted using a unique radar data record (23 years) and a very dense rain-gauge network in the Eastern Mediterranean area (northern Israel). Radar-IDF curves, together with an ensemble of point-based IDF curves representing the radar subpixel extreme rainfall variability, were developed fitting Generalized Extreme Value (GEV) distributions to annual rainfall maxima. It was found that the mean areal extreme rainfall derived from the radar underestimate most of the extreme values computed for point locations within the radar pixel (on average, ∼70%). The subpixel variability of rainfall extreme was found to increase with longer return periods and shorter durations (e.g. from a maximum variability of 10% for a return period of 2 years and a duration of 4 h to 30% for 50 years return period and 20 min duration). For the longer return periods, a considerable enhancement of extreme rainfall variability was found when stochastic (natural) climate variability was taken into account. Bounding the range of the subpixel extreme rainfall derived from radar-IDF can be of major importance for different applications that require very local estimates of rainfall extremes.

  11. Advanced Meteor radar at Tirupati: System details and first results

    Science.gov (United States)

    Sunkara, Eswaraiah; Gurubaran, Subramanian; Sundararaman, Sathishkumar; Venkat Ratnam, Madineni; Karanam, Kishore Kumar; Eethamakula, Kosalendra; Vijaya Bhaskara Rao, S.

    An advanced meteor radar viz., Enhanced Meteor Detection Radar (EMDR) operating at 35.25 MHz is installed at Sri Venkateswara University (SVU), Tirupati (13.63oN, 79.4oE), India, in the month of August 2013. Present communication describes the need for the meteor radar at present location, system description, its measurement techniques, its variables and comparison of measured mean winds with contemporary radars over the Indian region. The present radar site is selected to fill the blind region of Gadanki (13.5oN, 79.2oE) MST radar, which covers mesosphere and lower thermosphere (MLT) region (70-110 km). By modifying the receiving antenna structure and elements, this radar is capable of providing accurate wind information between 70 and 110 km unlike other similar radars. Height covering region is extended by increasing the meteor counting capacity by modifying the receiving antenna structure and elements and hence its wind estimation limits extended below and above of 80 and 100 km, respectively. In the present study, we also made comparison of horizontal winds in the MLT region with those measured by similar and different (MST and MF radars) techniques over the Indian region including the model (HWM 07) data sets. The comparison showed a very good agreement between the overlapping altitudes (82-98 km) of different radars. Zonal winds compared very well as that of meridional winds. The observed discrepancies and limitations in the wind measurement are discussed. This new radar is expected to play important role in understanding the vertical and lateral coupling by forming a unique local network.

  12. An Online Multisensor Data Fusion Framework for Radar Emitter Classification

    Directory of Open Access Journals (Sweden)

    Dongqing Zhou

    2016-01-01

    Full Text Available Radar emitter classification is a special application of data clustering for classifying unknown radar emitters in airborne electronic support system. In this paper, a novel online multisensor data fusion framework is proposed for radar emitter classification under the background of network centric warfare. The framework is composed of local processing and multisensor fusion processing, from which the rough and precise classification results are obtained, respectively. What is more, the proposed algorithm does not need prior knowledge and training process; it can dynamically update the number of the clusters and the cluster centers when new pulses arrive. At last, the experimental results show that the proposed framework is an efficacious way to solve radar emitter classification problem in networked warfare.

  13. The influence of management and environment on local health department organizational structure and adaptation: a longitudinal network analysis.

    Science.gov (United States)

    Keeling, Jonathan W; Pryde, Julie A; Merrill, Jacqueline A

    2013-01-01

    The nation's 2862 local health departments (LHDs) are the primary means for assuring public health services for all populations. The objective of this study is to assess the effect of organizational network analysis on management decisions in LHDs and to demonstrate the technique's ability to detect organizational adaptation over time. We conducted a longitudinal network analysis in a full-service LHD with 113 employees serving about 187,000 persons. Network survey data were collected from employees at 3 times: months 0, 8, and 34. At time 1 the initial analysis was presented to LHD managers as an intervention with information on evidence-based management strategies to address the findings. At times 2 and 3 interviews documented managers' decision making and events in the task environment. Response rates for the 3 network analyses were 90%, 97%, and 83%. Postintervention (time 2) results showed beneficial changes in network measures of communication and integration. Screening and case identification increased for chlamydia and for gonorrhea. Outbreak mitigation was accelerated by cross-divisional teaming. Network measurements at time 3 showed LHD adaptation to H1N1 and budget constraints with increased centralization. Task redundancy increased dramatically after National Incident Management System training. Organizational network analysis supports LHD management with empirical evidence that can be translated into strategic decisions about communication, allocation of resources, and addressing knowledge gaps. Specific population health outcomes were traced directly to management decisions based on network evidence. The technique can help managers improve how LHDs function as organizations and contribute to our understanding of public health systems.

  14. The new Passive microwave Neural network Precipitation Retrieval (PNPR algorithm for the cross-track scanning ATMS radiometer: description and verification study over Europe and Africa using GPM and TRMM spaceborne radars

    Directory of Open Access Journals (Sweden)

    P. Sanò

    2016-11-01

    Full Text Available The objective of this paper is to describe the development and evaluate the performance of a completely new version of the Passive microwave Neural network Precipitation Retrieval (PNPR v2, an algorithm based on a neural network approach, designed to retrieve the instantaneous surface precipitation rate using the cross-track Advanced Technology Microwave Sounder (ATMS radiometer measurements. This algorithm, developed within the EUMETSAT H-SAF program, represents an evolution of the previous version (PNPR v1, developed for AMSU/MHS radiometers (and used and distributed operationally within H-SAF, with improvements aimed at exploiting the new precipitation-sensing capabilities of ATMS with respect to AMSU/MHS. In the design of the neural network the new ATMS channels compared to AMSU/MHS, and their combinations, including the brightness temperature differences in the water vapor absorption band, around 183 GHz, are considered. The algorithm is based on a single neural network, for all types of surface background, trained using a large database based on 94 cloud-resolving model simulations over the European and the African areas. The performance of PNPR v2 has been evaluated through an intercomparison of the instantaneous precipitation estimates with co-located estimates from the TRMM Precipitation Radar (TRMM-PR and from the GPM Core Observatory Ku-band Precipitation Radar (GPM-KuPR. In the comparison with TRMM-PR, over the African area the statistical analysis was carried out for a 2-year (2013–2014 dataset of coincident observations over a regular grid at 0.5°  ×  0.5° resolution. The results have shown a good agreement between PNPR v2 and TRMM-PR for the different surface types. The correlation coefficient (CC was equal to 0.69 over ocean and 0.71 over vegetated land (lower values were obtained over arid land and coast, and the root mean squared error (RMSE was equal to 1.30 mm h−1 over ocean and 1.11 mm h−1 over

  15. Mobile Carrier Selection In A Post-Conflict Environment – The Primacy Of Ethnicity Over Conventional Network Effects

    Directory of Open Access Journals (Sweden)

    Zaimović Tarik

    2015-12-01

    Full Text Available In this paper we analyze determinants which affect the selection of mobile carriers in a post-conflict environment - Bosnia and Herzegovina. We apply relevant probability modelling to test perceptions of individual respondents on different network effects obtained through a targeted representative survey. Furthermore, we explore whether some non-traditional influences might affect costumers, focusing on the role of demographic characteristics. Our results confirm that conventional network effects have a role in carrier selection, although they are different across carriers. However, we identify that the ethnicity of respondents overwhelms the traditional network effects by having the highest magnitude in the model. Our findings show that the “ethnic affiliation” of mobile carriers, attributed by the users, remains a persistent factor in attracting and keeping telecommunication costumers in Bosnia and Herzegovina.

  16. Wind Profiling Radar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Clutter present in radar return signals as used for wind profiling is substantially removed by carrying out a Daubechies wavelet transformation on a time series of...

  17. Smoothing Motion Estimates for Radar Motion Compensation.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-07-01

    Simple motion models for complex motion environments are often not adequate for keeping radar data coherent. Eve n perfect motion samples appli ed to imperfect models may lead to interim calculations e xhibiting errors that lead to degraded processing results. Herein we discuss a specific i ssue involving calculating motion for groups of pulses, with measurements only available at pulse-group boundaries. - 4 - Acknowledgements This report was funded by General A tomics Aeronautical Systems, Inc. (GA-ASI) Mission Systems under Cooperative Re search and Development Agre ement (CRADA) SC08/01749 between Sandia National Laboratories and GA-ASI. General Atomics Aeronautical Systems, Inc. (GA-ASI), an affilia te of privately-held General Atomics, is a leading manufacturer of Remotely Piloted Aircraft (RPA) systems, radars, and electro-optic and rel ated mission systems, includin g the Predator(r)/Gray Eagle(r)-series and Lynx(r) Multi-mode Radar.

  18. ERT Conditions for Productive Learning in Networked Learning Environments: Leadership Report

    DEFF Research Database (Denmark)

    Dirckinck-Holmfeld, Lone

    This report provides a concluding account of the activities within the European Research Team: Conditions for Productive Learning in Networked Learning Environmentments......This report provides a concluding account of the activities within the European Research Team: Conditions for Productive Learning in Networked Learning Environmentments...

  19. New Vertical Handover Method to Optimize Utilization of Wireless Local Area Network in High-Speed Environment.

    Science.gov (United States)

    Yew, Hoe Tung; Supriyanto, Eko; Satria, Muhammad Haikal; Hau, Yuan Wen

    2016-01-01

    In heterogeneous wireless networks, wireless local area network (WLAN) is highly preferred by mobile terminals (MTs) owing to its high transmission bandwidth and low access cost. However, in high-speed environment, handover from a cellular network to a WLAN cell will lead to a high number of handover failures and unnecessary handovers due to the WLAN coverage limitation and will become worse at high speed. A new vertical handover method is proposed to minimize the probability of handover failure and unnecessary handover while maximizing the usage of WLAN in high-speed environment. The simulation results show that the proposed method kept the probability of handover failure and unnecessary handover below 0.5% and 1%, respectively. Compared with previous studies, the proposed method reduced the number of handover failures and unnecessary handovers up to 80.0% and 97.7%, respectively, while the MT is highly mobile. Using the proposed prediction method, the MT can benefit high bandwidth and low network access cost from the WLAN with minimum interruption regardless of speed.

  20. New Vertical Handover Method to Optimize Utilization of Wireless Local Area Network in High-Speed Environment.

    Directory of Open Access Journals (Sweden)

    Hoe Tung Yew

    Full Text Available In heterogeneous wireless networks, wireless local area network (WLAN is highly preferred by mobile terminals (MTs owing to its high transmission bandwidth and low access cost. However, in high-speed environment, handover from a cellular network to a WLAN cell will lead to a high number of handover failures and unnecessary handovers due to the WLAN coverage limitation and will become worse at high speed. A new vertical handover method is proposed to minimize the probability of handover failure and unnecessary handover while maximizing the usage of WLAN in high-speed environment. The simulation results show that the proposed method kept the probability of handover failure and unnecessary handover below 0.5% and 1%, respectively. Compared with previous studies, the proposed method reduced the number of handover failures and unnecessary handovers up to 80.0% and 97.7%, respectively, while the MT is highly mobile. Using the proposed prediction method, the MT can benefit high bandwidth and low network access cost from the WLAN with minimum interruption regardless of speed.

  1. Artificial neural network modeling in competitive adsorption of phenol and resorcinol from water environment using some carbonaceous adsorbents.

    Science.gov (United States)

    Aghav, R M; Kumar, Sunil; Mukherjee, S N

    2011-04-15

    This paper illustrates the application of artificial neural network (ANN) for prediction of performances in competitive adsorption of phenol and resorcinol from aqueous solution by conventional and low cost carbonaceous adsorbent materials, such as activated carbon (AC), wood charcoal (WC) and rice husk ash (RHA). The three layer's feed forward neural network with back propagation algorithm in MATLAB environment was used for estimation of removal efficiencies of phenol and resorcinol in bi-solute water environment based on 29 sets of laboratory batch study results. The input parameters used for training of the neural network include amount of adsorbent (g/L), initial concentrations of phenol (mg/L) and resorcinol (mg/L), contact time (h), and pH. The removal efficiencies of phenol and resorcinol were considered as an output of the neural network. The performances of the developed ANN models were also measured using statistical parameters, such as mean error, mean square error, root mean square error, and linear regression. The comparison of the removal efficiencies of pollutants using ANN model and experimental results showed that ANN modeling in competitive adsorption of phenolic compounds reasonably corroborated with the experimental results. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Precipitation and microphysical studies with a low cost high resolution X-band radar: an innovative project prospective

    Directory of Open Access Journals (Sweden)

    J. Van Baelen

    2009-03-01

    Full Text Available This paper describes an innovative project which has just been launched at the "Laboratoire de Météorologie Physique" (LaMP in Clermont-Ferrand in collaboration with the "Meteorologische Institut" in Hamburg, where a low cost X-band high resolution precipitation radar is combined with supporting measurements and a bin microphysical cloud resolving model in order to develop adapted Z–R relationships for accurate rain rate estimates over a local area such as a small catchment basin, an urban complex or even an agriculture domain.

    In particular, the use of K-band micro rain radars which can retrieve vertical profiles of drop size distribution and the associated reflectivity will be used to perform direct comparisons with X-band radar volume samples while a network of rain-gauges provides ground truth to which our rain estimates will be compared. Thus, the experimental suite of instrumentation should provide a detailed characterization of the various rain regimes and their associated Z–R relationship. Furthermore, we will make use of the hilly environment of the radar to test the use of novel attenuation methods in order to estimate rainfall rates.

    A second important aspect of this work is to use the detailed cloud modeling available at LaMP. Simulations of precipitating clouds in highly resolved 3-D dynamics model allow predicting the spectra of rain drops and precipitating ice particles. Radar reflectivity determined from these model studies will be compared with the observations in order to better understand which raindrop size spectrum shape factor should be applied to the radar algorithms as a function of the type of precipitating cloud. Likewise, these comparisons between the modeled and the observed reflectivity will also give us the opportunity to further improve our model microphysics and the parameterizations for meso-scale models.

  3. Insights into factors contributing to the observability of a submarine at periscope depth by modern radar, Part 2: EM simulation of mast RCS in a realistic sea surface environment

    CSIR Research Space (South Africa)

    Smit, JC

    2012-09-01

    Full Text Available Recently, a set of high resolution radar measurements were undertaken in South Africa to gain insight into factors influencing the detectability of submarine masts deployed under realistic operational conditions. The measurements, processing results...

  4. Car-to-Pedestrian Communication Safety System Based on the Vehicular Ad-Hoc Network Environment: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Peng Jing

    2017-10-01

    Full Text Available With the unparalleled growth of motor vehicles, traffic accident between pedestrians and vehicles is one of the most serious issues in the word-wild. Plenty of injuries and fatalities are caused by the traffic accidents and crashes. The connected vehicular ad hoc network as an emerging approach which has the potential to reduce and even avoid accidents have been focused on by many researchers. A large number of car-to-pedestrian communication safety systems based on the vehicular ad hoc network are researching and developing. However, to our limited knowledge, a systematic review about the car-to-pedestrian communication safety system based on the vehicular ad-hoc network has not be written. The purpose and goal of this review is to systematically evaluate and access the reliability of car-to-pedestrian communication safety system based on the vehicular ad-hoc network environment and provide some recommendations for the future works according to throwing some light on the previous literatures. A quality evaluation was developed through established items and instruments tailored to this review. Future works are needed to focus on developing a valid as well as effective communication safety system based on the vehicular ad hoc network to protect the vulnerable road users.

  5. The impact of moving to a novel environment on social networks, activity and wellbeing in two new world primates.

    Science.gov (United States)

    Dufour, V; Sueur, C; Whiten, A; Buchanan-Smith, H M

    2011-08-01

    Among the stressors that can affect animal welfare in zoos, the immediate effect of relocation to a novel environment is one that has received little attention in the literature. Here, we compare the social network, daily activity and the expression of stress-related behavior in capuchins (Cebus apella) and squirrel monkeys (Saimiri sciureus) before and just after they were relocated to a new enriched enclosure. Results showed similar immediate responses to the move in the two species. Both showed a substantial increase in the time spent resting and spent more time in the highest and "safest" part of their enclosure after relocation. Both capuchins and squirrel monkeys spent significantly more time in close proximity to other group members after relocation, compared to before. In squirrel monkeys, the structure of the social network, which was initially correlated to affiliation, was no longer so after the move. In capuchins, the network analysis showed that individuals regrouped by age, with the youngsters who were potentially more affected by stress being in the center of the network. Social network analysis helped to achieve a more complete picture of how individuals were affected by relocation. We suggest that this type of analysis should be used alongside traditional methods of observation and analysis to encompass the most complex aspects of animal behavior in times of stress and to improve welfare. © 2011 Wiley-Liss, Inc.

  6. Policy gaps and technological deficiencies in social networking environments: Implications for information sharing

    Directory of Open Access Journals (Sweden)

    Stephen M. Mutula

    2013-02-01

    Full Text Available Background: With the growing adoption and acceptance of social networking, there are increased concerns about the violation of the users’ legitimate rights such as privacy, confidentiality, trust, security, safety, content ownership, content accuracy, integrity, access and accessibility to computer and digital networks amongst others.Objectives: The study sought to investigate the following research objectives to: (1 describe the types of social networks, (2 examine global penetration of the social networks, (3 outline the users’ legitimate rights that must be protected in the social networking sites (SNS, (4 determine the methods employed by SNS to protect the users’ legitimate rights and (5 identify the policy gaps and technological deficiencies in the protection of the users’ legitimate rights in the SNS.Method: A literature survey and content analysis of the SNS user policies were used to address objective four and objective five respectively.Results: The most actively used sites were Facebook and Twitter. Asian markets were leading in participation and in creating content than any other region. Business, education, politics and governance sectors were actively using social networking sites. Social networking sites relied upon user trust and internet security features which however, were inefficient and inadequate.Conclusion: Whilst SNS were impacting people of varying ages and of various professional persuasions, there were increased concerns about the violation and infringement of the users’ legitimate rights. Reliance on user trust and technological security features SNS to protect the users’ legitimate rights seemed ineffectual and inadequate.

  7. Policy gaps and technological deficiencies in social networking environments: Implications for information sharing

    Directory of Open Access Journals (Sweden)

    Stephen M. Mutula

    2013-06-01

    Full Text Available Background: With the growing adoption and acceptance of social networking, there are increased concerns about the violation of the users’ legitimate rights such as privacy, confidentiality, trust, security, safety, content ownership, content accuracy, integrity, access and accessibility to computer and digital networks amongst others.Objectives: The study sought to investigate the following research objectives to: (1 describe the types of social networks, (2 examine global penetration of the social networks, (3 outline the users’ legitimate rights that must be protected in the social networking sites (SNS, (4 determine the methods employed by SNS to protect the users’ legitimate rights and (5 identify the policy gaps and technological deficiencies in the protection of the users’ legitimate rights in the SNS.Method: A literature survey and content analysis of the SNS user policies were used to address objective four and objective five respectively.Results: The most actively used sites were Facebook and Twitter. Asian markets were leading in participation and in creating content than any other region. Business, education, politics and governance sectors were actively using social networking sites. Social networking sites relied upon user trust and internet security features which however, were inefficient and inadequate.Conclusion: Whilst SNS were impacting people of varying ages and of various professional persuasions, there were increased concerns about the violation and infringement of the users’ legitimate rights. Reliance on user trust and technological security features SNS to protect the users’ legitimate rights seemed ineffectual and inadequate.

  8. Digital journalism in the Network Society: innovating in a competitive environment

    Directory of Open Access Journals (Sweden)

    José-Alberto García-Avilés

    2017-01-01

    Full Text Available Internet’s rise as a dominant medium has transformed the ecosystem of the Network Society, bringing about deep changes in the economy, politics, culture, leisure and the public sphere (Castells, 1997. As a result, millions of communicators are connected to a Network increasingly intertwined, reaching global dimensions. Network communication pushes the limits and breaks frontiers: any isolated incident might originate international consequences, such as we have seen with Fidel Castro’s death, the victory of Donald Trump in the U.S. presidential elections, the referendum about the peace process in Colombia or the “Brexit” in the United Kingdom.

  9. ENERGY-NET (Energy, Environment and Society Learning Network): Enhancing opportunities for learning using an Earth systems science framework

    Science.gov (United States)

    Elliott, E. M.; Bain, D. J.; Divers, M. T.; Crowley, K. J.; Povis, K.; Scardina, A.; Steiner, M.

    2012-12-01

    We describe a newly funded collaborative NSF initiative, ENERGY-NET (Energy, Environment and Society Learning Network), that brings together the Carnegie Museum of Natural History (CMNH) with the Learning Science and Geoscience research strengths at the University of Pittsburgh. ENERGY-NET aims to create rich opportunities for participatory learning and public education in the arena of energy, the environment, and society using an Earth systems science framework. We build upon a long-established teen docent program at CMNH and to form Geoscience Squads comprised of underserved teens. Together, the ENERGY-NET team, including museum staff, experts in informal learning sciences, and geoscientists spanning career stage (undergraduates, graduate students, faculty) provides inquiry-based learning experiences guided by Earth systems science principles. Together, the team works with Geoscience Squads to design "Exploration Stations" for use with CMNH visitors that employ an Earth systems science framework to explore the intersecting lenses of energy, the environment, and society. The goals of ENERGY-NET are to: 1) Develop a rich set of experiential learning activities to enhance public knowledge about the complex dynamics between Energy, Environment, and Society for demonstration at CMNH; 2) Expand diversity in the geosciences workforce by mentoring underrepresented teens, providing authentic learning experiences in earth systems science and life skills, and providing networking opportunities with geoscientists; and 3) Institutionalize ENERGY-NET collaborations among geosciences expert, learning researchers, and museum staff to yield long-term improvements in public geoscience education and geoscience workforce recruiting.

  10. State of the (net)work address Developing criteria for applying social networking to the work environment.

    Science.gov (United States)

    Valdez, André Calero; Schaar, Anne Kathrin; Ziefle, Martina

    2012-01-01

    In an increasingly faster paced innovative world, maintaining the ability to innovate in spite of an aging work force will become every company's strongest leverage for success. Tapping the latent knowledge resources and creativity of overlooked employees and persisting crucial information for business conduct are promising results for social networking sites (SNS) in a working context. Usability and usefulness are exponential factors in creating a successful SNS. In order to make a SNS usable for a heterogeneous user group, analyses of user diversity in regard to social media need to be done. Furthermore differences in communication medium and frequency in regard to age, content, hierarchy position, departmental thresholds and company size need to be analyzed. For analysis purposes both qualitative and quantitative research methods were applied. Strong effects of age and communication content were found in survey with 194 participants.

  11. Towards a Framework for Self-Adaptive Reliable Network Services in Highly-Uncertain Environments

    DEFF Research Database (Denmark)

    Grønbæk, Lars Jesper; Schwefel, Hans-Peter; Ceccarelli, Andrea

    2010-01-01

    to improve resilience of end-node services. In this paper we present a framework, called ODDR (Observation, Diagnosis, Decision, Remediation), for improving resilience of network based services through integration of self-adaptive monitoring services, network diagnosis, decision actions, and finally......In future inhomogeneous, pervasive and highly dynamic networks, end-nodes may often only rely on unreliable and uncertain observations to diagnose hidden network states and decide upon possible remediation actions. Inherent challenges exists to identify good and timely decision strategies...... execution (and monitoring) of remediation actions. We detail the motivations to the ODDR design, then we present its architecture, and finally we describe our current activities towards the realization and assessment of the framework services and the main results currently achieved....

  12. Study of RF Propagation Characteristics for Wireless Sensor Networks in Railroad Environments

    Science.gov (United States)

    2010-01-01

    The freight railroad industry in North America is exerting efforts to leverage Wireless Sensor Networks to monitor systems and components on railcars. This allows fault detection and accident prevention even while a train is moving. Railcars, constru...

  13. Feasibility of integrating other federal information systems into the Global Network of Environment and Technology, GNET{reg_sign}

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

    The Global Environment and Technology Enterprise (GETE) of the Global Environment and Technology Foundation (GETF) has been tasked by the US Department of Energy`s (DOE), Federal Energy Technology Center (FETC) to assist in reducing DOE`s cost for the Global Network of Environment and Technology (GNET{reg_sign}). As part of this task, GETE is seeking federal partners to invest in GNET{reg_sign}. The authors are also seeking FETC`s commitment to serve as GNET`s federal agency champion promoting the system to potential agency partners. This report assesses the benefits of partnering with GNET{reg_sign} and provides recommendations for identifying and integrating other federally funded (non-DOE) environmental information management systems into GNET{reg_sign}.

  14. Simulation Based: Study and Analysis of Routing Protocol in Vehicular Ad-hoc Network Environment

    OpenAIRE

    Khairnar, Mrs. Vaishali D.; Pradhan, Dr. S. N.

    2014-01-01

    A Vehicular Ad hoc Network (VANET) consists of vehicles which communicate with each other and exchange data via wireless communication links available between the vehicles which are in communication ranges of vehicles to improve the road safety in city. The communication between vehicles is used to provide road safety, comfort and entertainment. The performance of communication depends on how better routing takes place in the network. Routing data between the source and destination vehicle de...

  15. Energy efficient routing in mobile ad-hoc networks for Healthcare Environments

    OpenAIRE

    Sohail Abid; Imran Shafi; Shahid Abid

    2013-01-01

    The modern and innovative medical applications based on wireless network are being developed in the commercial sectors as well as in research. The emerging wireless networks are rapidly becoming a fundamental part of medical solutions due to increasing accessibility for healthcare professionals/patients reducing healthcare costs. Discovering the routes among hosts that are energy efficient without compromise on smooth communication is desirable. This work investigates energy efficiency of som...

  16. Wave Activity (Planetary, Tidal) throughout the Middle Atmoshere (25-100 km) over the CUJO Network: Satellite and Medium Frequency (MF) Radar Observations

    Science.gov (United States)

    Manson, A.; Meek, C.; Chshyolkova, T.; Avery, S.; Thorsen, D.; MacDougall, J.; Hocking, W.; Murayama, Y.; Igarashi, K.

    Planetary and tidal wave activity in the mesosphere-lower thermosphere (MLT), and assessment of wave activity sources in the lower atmosphere, are studied using combinations of ground based (GB) and satellite instruments (2000-2002). CUJO (Canada U.S. Japan Opportunity) comprises MF radar (MFR) systems at London (43°N, 81°W), Platteville (40°N, 105°W), Saskatoon (52°N, 107°W), Wakkanai (45°N, 142°E) and Yamagawa (31°N, 131°E). It offers a significant mid-latitude 7,000 km longitudinal sector in the North American-Pacific region, and a useful range of latitudes (12-14°) at two longitudes. CUJO provides winds and tides 70-100km. Satellite data include the daily values of the total ozone column measured by the Earth Probe (EP) TOMS (Total Ozone Mapping Spectrometer) and provides a measure of tropopause-lower stratospheric planetary wave activity as well as ozone variability. The so-called UKMO data (an assimilation system) are used for correlative purposes with the TOMS data. Climatologies of ozone and winds/tides involving frequency versus time (wavelet) contour plots for periods from 2-d to 30-d and the interval from mid 2000 to 2002, show that the changes with altitude, longitude and latitude are very significant and distinctive. Geometric-mean wavelets for the region of the 40°N MFRs demonstrate occasions during the autumn, winter and spring months when there are similarities in the spectral features of the lower atmosphere and at mesopause (85km) heights. Both direct planetary wave (PW) propagation into the MLT, non-linear PW-tide interactions, and disturbances in MLT tides associated with fluctuations in the ozone forcing are considered to be possible coupling processes. The complex horizontal wave numbers of the longer period oscillations are provided in frequency contour plots for the TOMS and UKMO data to demonstrate the differences between lower atmospheric and MLT wave motions and their directions of propagation.

  17. CAMEX-4 TOGA RADAR V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The TOGA radar dataset consists of browse and radar data collected from the TOGA radar during the CAMEX-4 experiment. TOGA is a C-band linear polarized doppler radar...

  18. Chaos Through-Wall Imaging Radar

    Science.gov (United States)

    Xu, Hang; Wang, Bingjie; Zhang, Jianguo; Liu, Li; Li, Ying; Wang, Yuncai; Wang, Anbang

    2017-12-01

    We experimentally demonstrate a chaos through-wall imaging radar using ultra-wideband chaotic-pulse-position modulation (CPPM) microwave signal. The CPPM signal based on logistic map with 1-ns pulse width and 1-GHz bandwidth is implemented by a field programmable gate array (FPGA) and then up-converted as the radar transmitting signal. Two-dimensional image of human objects behind obstacles is obtained by correlation method and back projection algorithm. Our experiments successfully perform through-wall imaging for single and multiple human objects through 20-cm thick wall. The down-range resolution of the proposed radar is 15 cm. Furthermore, the anti-jamming properties of the proposed radar in CPPM jamming, linear frequency-modulated jamming, and Gaussian noise jamming environments are demonstrated by electromagnetic simulations using the finite-difference time-domain. The simulation results show the CPPM microwave signal possesses excellent jamming immunity to the noise and radio frequency interference, which makes it perform superbly in multiradar environments.

  19. Mapping wintering waterfowl distributions using weather surveillance radar.

    Science.gov (United States)

    Buler, Jeffrey J; Randall, Lori A; Fleskes, Joseph P; Barrow, Wylie C; Bogart, Tianna; Kluver, Daria

    2012-01-01

    The current network of weather surveillance radars within the United States readily detects flying birds and has proven to be a useful remote-sensing tool for ornithological study. Radar reflectivity measures serve as an index to bird density and have been used to quantitatively map landbird distributions during migratory stopover by sampling birds aloft at the onset of nocturnal migratory flights. Our objective was to further develop and validate a similar approach for mapping wintering waterfowl distributions using weather surveillance radar observations at the onset of evening flights. We evaluated data from the Sacramento, CA radar (KDAX) during winters 1998-1999 and 1999-2000. We determined an optimal sampling time by evaluating the accuracy and precision of radar observations at different times during the onset of evening flight relative to observed diurnal distributions of radio-marked birds on the ground. The mean time of evening flight initiation occurred 23 min after sunset with the strongest correlations between reflectivity and waterfowl density on the ground occurring almost immediately after flight initiation. Radar measures became more spatially homogeneous as evening flight progressed because birds dispersed from their departure locations. Radars effectively detected birds to a mean maximum range of 83 km during the first 20 min of evening flight. Using a sun elevation angle of -5° (28 min after sunset) as our optimal sampling time, we validated our approach using KDAX data and additional data from the Beale Air Force Base, CA (KBBX) radar during winter 1998-1999. Bias-adjusted radar reflectivity of waterfowl aloft was positively related to the observed diurnal density of radio-marked waterfowl locations on the ground. Thus, weather radars provide accurate measures of relative wintering waterfowl density that can be used to comprehensively map their distributions over large spatial extents.

  20. Surveillance Unattended Foliage Penetrating Radar for Border Control and Homeland Protection

    Directory of Open Access Journals (Sweden)

    Felicia Amato

    2013-06-01

    Full Text Available The increasing request for safety, security and environment protection at local and national level reveal the deficiency of the traditional surveillance and control centers to satisfy the needs and requirements of modern border control systems for homeland protection where land border is expected to be monitored as well as the maritime one. This is, for instance, the case of any land border affected by hidden immigration and/or illegal traffics as well as any small areas such as critical infrastructures or military/ civilian posts in forest or jungle environment characterized by vegetation. In such challenging environment, logistics constraints strongly recommend to have very low power devices able to operate months or years without maintenance. A such scenario should be the perfect place for implementing an Unattended Ground Sensors (UGS network making use FOliage PENetration (FOPEN radar for border control. The paper aims to present the basic characteristics and preliminary results of a Surveillance Unattended FOPEN (SUF radar suitable for detecting moving targets, people or vehicles, in dense forest environment.