WorldWideScience

Sample records for frequency spectrum allocation

  1. Radio resource allocation and dynamic spectrum access

    CERN Document Server

    Benmammar , Badr

    2013-01-01

    We are currently witnessing an increase in telecommunications norms and standards given the recent advances in this field. The increasing number of normalized standards paves the way for an increase in the range of services available for each consumer. Moreover, the majority of available radio frequencies have already been allocated. This explains the emergence of cognitive radio (CR) - the sharing of the spectrum between a primary user and a secondary user.In this book, we will present the state of the art of the different techniques for spectrum access using cooperation and competit

  2. Potential of dynamic spectrum allocation in LTE macro networks

    Science.gov (United States)

    Hoffmann, H.; Ramachandra, P.; Kovács, I. Z.; Jorguseski, L.; Gunnarsson, F.; Kürner, T.

    2015-11-01

    In recent years Mobile Network Operators (MNOs) worldwide are extensively deploying LTE networks in different spectrum bands and utilising different bandwidth configurations. Initially, the deployment is coverage oriented with macro cells using the lower LTE spectrum bands. As the offered traffic (i.e. the requested traffic from the users) increases the LTE deployment evolves with macro cells expanded with additional capacity boosting LTE carriers in higher frequency bands complemented with micro or small cells in traffic hotspot areas. For MNOs it is crucial to use the LTE spectrum assets, as well as the installed network infrastructure, in the most cost efficient way. The dynamic spectrum allocation (DSA) aims at (de)activating the available LTE frequency carriers according to the temporal and spatial traffic variations in order to increase the overall LTE system performance in terms of total network capacity by reducing the interference. This paper evaluates the DSA potential of achieving the envisaged performance improvement and identifying in which system and traffic conditions the DSA should be deployed. A self-optimised network (SON) DSA algorithm is also proposed and evaluated. The evaluations have been carried out in a hexagonal and a realistic site-specific urban macro layout assuming a central traffic hotspot area surrounded with an area of lower traffic with a total size of approximately 8 × 8 km2. The results show that up to 47 % and up to 40 % possible DSA gains are achievable with regards to the carried system load (i.e. used resources) for homogenous traffic distribution with hexagonal layout and for realistic site-specific urban macro layout, respectively. The SON DSA algorithm evaluation in a realistic site-specific urban macro cell deployment scenario including realistic non-uniform spatial traffic distribution shows insignificant cell throughput (i.e. served traffic) performance gains. Nevertheless, in the SON DSA investigations, a gain of up

  3. Dynamic fair node spectrum allocation for ad hoc networks using random matrices

    Science.gov (United States)

    Rahmes, Mark; Lemieux, George; Chester, Dave; Sonnenberg, Jerry

    2015-05-01

    Dynamic Spectrum Access (DSA) is widely seen as a solution to the problem of limited spectrum, because of its ability to adapt the operating frequency of a radio. Mobile Ad Hoc Networks (MANETs) can extend high-capacity mobile communications over large areas where fixed and tethered-mobile systems are not available. In one use case with high potential impact, cognitive radio employs spectrum sensing to facilitate the identification of allocated frequencies not currently accessed by their primary users. Primary users own the rights to radiate at a specific frequency and geographic location, while secondary users opportunistically attempt to radiate at a specific frequency when the primary user is not using it. We populate a spatial radio environment map (REM) database with known information that can be leveraged in an ad hoc network to facilitate fair path use of the DSA-discovered links. Utilization of high-resolution geospatial data layers in RF propagation analysis is directly applicable. Random matrix theory (RMT) is useful in simulating network layer usage in nodes by a Wishart adjacency matrix. We use the Dijkstra algorithm for discovering ad hoc network node connection patterns. We present a method for analysts to dynamically allocate node-node path and link resources using fair division. User allocation of limited resources as a function of time must be dynamic and based on system fairness policies. The context of fair means that first available request for an asset is not envied as long as it is not yet allocated or tasked in order to prevent cycling of the system. This solution may also save money by offering a Pareto efficient repeatable process. We use a water fill queue algorithm to include Shapley value marginal contributions for allocation.

  4. The frequency spectrum crisis - Issues and answers

    Science.gov (United States)

    Armes, G. L.

    The frequency spectrum represents a unique resource which can be overtaxed. In the present investigation, it is attempted to evalute the demand for satellite and microwave services. Dimensions of increased demand are discussed, taking into account developments related to the introduction of the personal computer, the activities of the computer and communications industries in preparation for the office of the future, and electronic publishing. Attention is given to common carrier spectrum congestion, common carrier microwave, satellite communications, teleports, international implications, satellite frequency bands, satellite spectrum implications, alternatives regarding the utilization of microwave frequency bands, U.S. Government spectrum utilization, and the impact at C-band.

  5. Experimental Demonstration of Mixed Formats and Bit Rates Signal Allocation for Spectrum-flexible Optical Networking

    DEFF Research Database (Denmark)

    Borkowski, Robert; Karinou, Fotini; Angelou, Marianna

    2012-01-01

    We report on an extensive experimental study for adaptive allocation of 16-QAM and QPSK signals inside spectrum flexible heterogeneous superchannel. Physical-layer performance parameters are extracted for use in resource allocation mechanisms of future flexible networks....

  6. Intra-regional Diffusion of Spectrum License Allocation Policies

    DEFF Research Database (Denmark)

    Pogrebnyakov, Nicolai; Maitland, Carleen F.

    2013-01-01

    -depth qualitative analyses to compare effects of various diffusion mechanisms; diffusion of spectrum license allocation policies at the regional level was more strongly driven by a policy’s likely effectiveness, as compared to potential payoffs for policymakers; and conversely, at the national level diffusion...... regions. Design/methodology/approach – A qualitative comparative case method is used. Cases are developed from secondary data from the European Union and South America, and analyzed at the national and regional levels. Findings – The results suggest: the expected utility model can be used for in...... was driven by both payoffs for the policymakers and likely policy effectiveness. Originality/value – The two academic contributions of the paper are its expansion of a unified policy diffusion model to simultaneously account for regional and national levels of governance, as well as for technological change...

  7. Exponential Frequency Spectrum in Magnetized Plasmas

    International Nuclear Information System (INIS)

    Pace, D. C.; Shi, M.; Maggs, J. E.; Morales, G. J.; Carter, T. A.

    2008-01-01

    Measurements of a magnetized plasma with a controlled electron temperature gradient show the development of a broadband spectrum of density and temperature fluctuations having an exponential frequency dependence at frequencies below the ion cyclotron frequency. The origin of the exponential frequency behavior is traced to temporal pulses of Lorentzian shape. Similar exponential frequency spectra are also found in limiter-edge plasma turbulence associated with blob transport. This finding suggests a universal feature of magnetized plasma turbulence leading to nondiffusive, cross-field transport, namely, the presence of Lorentzian shaped pulses

  8. Better bounds for incremental frequency allocation in bipartite graphs

    Czech Academy of Sciences Publication Activity Database

    Chrobak, M.; Jeż, Łukasz; Sgall, J.

    2013-01-01

    Roč. 514, 25 November (2013), s. 75-83 ISSN 0304-3975 R&D Projects: GA AV ČR IAA100190902; GA ČR GBP202/12/G061 Institutional support: RVO:67985840 Keywords : online algorithms * frequency allocation * graph algorithms Subject RIV: BA - General Mathematics Impact factor: 0.516, year: 2013 http://www.sciencedirect.com/science/article/pii/S0304397512004781

  9. Frequency spectrum of Calder Hall reactor noise

    International Nuclear Information System (INIS)

    Cummins, J.D.

    1960-01-01

    The frequency spectrum of the noise power of Calder Hall reactor No. 1 has been obtained by analysing a tape recording of the backed off power. The root mean square noise power due to all frequencies above 0.001 cycles per second was found to be 0.13%. The noise power for this reactor, is due mainly to modulations of the power level by reactivity variations caused in turn by gas temperature changes. These gas temperature changes are caused by a Cyclic variation in the feedwater regulator to the heat exchanger. The apparatus and method used to determine the noise power are described in this memorandum. It is shown that for frequencies in the range 0.001 to 0.030 cycles per second the noise spectrum falls at 60 decibels per decade of frequency. (author)

  10. Priority and Negotiation Based Dynamic Spectrum Allocation Scheme for Multiple Radio Access Network Operators

    Science.gov (United States)

    Kim, Hoon; Hyon, Taein; Lee, Yeonwoo

    Most of previous works have presented the dynamic spectrum allocation (DSA) gain achieved by utilizing the time or regional variations in traffic demand between multi-network operators (NOs). In this paper, we introduce the functionalities required for the entities related with the spectrum sharing and allocation and propose a spectrum allocation algorithm while considering the long-term priority between NOs, the priority between multiple class services, and the urgent bandwidth request. To take into account the priorities among the NOs and the priorities of multiple class services, a spectrum sharing metric (SSM) is proposed, while a negotiation procedure is proposed to treat the urgent bandwidth request.

  11. The international environment UNISPACE '82 and the ITU: A relationship between orbit-spectrum resource allocation and orbital debris

    Science.gov (United States)

    Olmstead, D.

    1985-01-01

    The 1985 Space WARC will examine and potentially modify the current geostationary orbit spectrum resource allocation methodology. Discussions in this international political environment could likely associate the geostationary orbital debris issue with the politicized issue of orbit spectrum allocation.

  12. A CR Spectrum Allocation Algorithm in Smart Grid Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Wei He

    2014-10-01

    Full Text Available Cognitive radio (CR method was introduced in smart grid communication systems to resolve potential maladies such as the coexistence of heterogeneous networks, overloaded data flow, diversity in data structures, and unstable quality of service (QOS. In this paper, a cognitive spectrum allocation algorithm based on non-cooperative game theory is proposed. The CR spectrum allocation model was developed by modifying the traditional game model via the insertion of a time variable and a critical function. The computing simulation result shows that the improved spectrum allocation algorithm can achieve stable spectrum allocation strategies and avoid the appearance of multi-Nash equilibrium at the expense of certain sacrifices in the system utility. It is suitable for application in distributed cognitive networks in power grids, thus contributing to the improvement of the isomerism and data capacity of power communication systems.

  13. Potential of dynamic spectrum allocation in LTE macro networks

    NARCIS (Netherlands)

    Hoffmann, H.; Ramachandra, P.; Kovacs, I.Z.; Jorguseski, L.; Gunnarsson, F.; Kurner, T.

    2015-01-01

    In recent years Mobile Network Operators (MNOs) worldwide are extensively deploying LTE networks in different spectrum bands and utilising different bandwidth configurations. Initially, the deployment is coverage oriented with macro cells using the lower LTE spectrum bands. As the offered traffic

  14. Attentional Allocation of Autism Spectrum Disorder Individuals: Searching for a Face-in-the-Crowd

    Science.gov (United States)

    Moore, David J.; Reidy, John; Heavey, Lisa

    2016-01-01

    A study is reported which tests the proposition that faces capture the attention of those with autism spectrum disorders less than a typical population. A visual search task based on the Face-in-the-Crowd paradigm was used to examine the attentional allocation of autism spectrum disorder adults for faces. Participants were required to search for…

  15. Resource allocation in shared spectrum access communications for operators with diverse service requirements

    Science.gov (United States)

    Kibria, Mirza Golam; Villardi, Gabriel Porto; Ishizu, Kentaro; Kojima, Fumihide; Yano, Hiroyuki

    2016-12-01

    In this paper, we study inter-operator spectrum sharing and intra-operator resource allocation in shared spectrum access communication systems and propose efficient dynamic solutions to address both inter-operator and intra-operator resource allocation optimization problems. For inter-operator spectrum sharing, we present two competent approaches, namely the subcarrier gain-based sharing and fragmentation-based sharing, which carry out fair and flexible allocation of the available shareable spectrum among the operators subject to certain well-defined sharing rules, traffic demands, and channel propagation characteristics. The subcarrier gain-based spectrum sharing scheme has been found to be more efficient in terms of achieved throughput. However, the fragmentation-based sharing is more attractive in terms of computational complexity. For intra-operator resource allocation, we consider resource allocation problem with users' dissimilar service requirements, where the operator supports users with delay constraint and non-delay constraint service requirements, simultaneously. This optimization problem is a mixed-integer non-linear programming problem and non-convex, which is computationally very expensive, and the complexity grows exponentially with the number of integer variables. We propose less-complex and efficient suboptimal solution based on formulating exact linearization, linear approximation, and convexification techniques for the non-linear and/or non-convex objective functions and constraints. Extensive simulation performance analysis has been carried out that validates the efficiency of the proposed solution.

  16. Holding-time-aware asymmetric spectrum allocation in virtual optical networks

    Science.gov (United States)

    Lyu, Chunjian; Li, Hui; Liu, Yuze; Ji, Yuefeng

    2017-10-01

    Virtual optical networks (VONs) have been considered as a promising solution to support current high-capacity dynamic traffic and achieve rapid applications deployment. Since most of the network services (e.g., high-definition video service, cloud computing, distributed storage) in VONs are provisioned by dedicated data centers, needing different amount of bandwidth resources in both directions, the network traffic is mostly asymmetric. The common strategy, symmetric provisioning of traffic in optical networks, leads to a waste of spectrum resources in such traffic patterns. In this paper, we design a holding-time-aware asymmetric spectrum allocation module based on SDON architecture and an asymmetric spectrum allocation algorithm based on the module is proposed. For the purpose of reducing spectrum resources' waste, the algorithm attempts to reallocate the idle unidirectional spectrum slots in VONs, which are generated due to the asymmetry of services' bidirectional bandwidth. This part of resources can be exploited by other requests, such as short-time non-VON requests. We also introduce a two-dimensional asymmetric resource model for maintaining idle spectrum resources information of VON in spectrum and time domains. Moreover, a simulation is designed to evaluate the performance of the proposed algorithm, and results show that our proposed asymmetric spectrum allocation algorithm can improve the resource waste and reduce blocking probability.

  17. Spectrum Situational Awareness Capability: The Military Need and Potential Implementation Issues

    Science.gov (United States)

    2006-10-01

    Management Sensor Systems Frequency Management EW Systems Frequency Management Allied Battlespace Spectrum Management Restricted Frequency List Frequency...Management Restricted Frequency List Frequency Allocation Table Civil Frequency Use Data Inputs Negotiation and allocation process © Dstl 2006 26th...Management Restricted Frequency List Data Inputs Negotiation and allocation process Frequency Allocation Table SSA ES INT COP etc WWW Spectrum

  18. A Spectrum Allocation Mechanism Based on HJ-DQPSO for Cognitive Radio Networks

    Directory of Open Access Journals (Sweden)

    Zhu Jiang

    2015-11-01

    Full Text Available In cognitive radio network model consisting of secondary users and primary users, in order to solve the difficult multi-objective spectrum allocation issue about maximizing network efficiency and users’ fairness to access network, this paper proposes a new discrete multi-objective combinatorial optimization mechanism—HJ-DQPSO based on Hooke Jeeves (HJ and Quantum Particle Swarm Optimization (QPSO algorithm. The mechanism adopts HJ algorithm to local search to prevent falling into the local optimum, and proposes a discrete QPSO algorithm to match the discrete spectrum assignment model. The mechanism has the advantages of approximating optimal solution, rapid convergence, less parameters, avoiding falling into local optimum. Compared with existing spectrum assignment algorithms, the simulation results show that according to different optimization objectives, the HJ-DQPSO optimization mechanism for multi-objective optimization can better approximate optimal solution and converge fast. We can obtain a reasonable spectrum allocation scheme in the case of satisfying multiple optimization objectives.

  19. Spectrum and power allocation in cognitive multi-beam satellite communications with flexible satellite payloads

    Science.gov (United States)

    Liu, Zhihui; Wang, Haitao; Dong, Tao; Yin, Jie; Zhang, Tingting; Guo, Hui; Li, Dequan

    2018-02-01

    In this paper, the cognitive multi-beam satellite system, i.e., two satellite networks coexist through underlay spectrum sharing, is studied, and the power and spectrum allocation method is employed for interference control and throughput maximization. Specifically, the multi-beam satellite with flexible payload reuses the authorized spectrum of the primary satellite, adjusting its transmission band as well as power for each beam to limit its interference on the primary satellite below the prescribed threshold and maximize its own achievable rate. This power and spectrum allocation problem is formulated as a mixed nonconvex programming. For effective solving, we first introduce the concept of signal to leakage plus noise ratio (SLNR) to decouple multiple transmit power variables in the both objective and constraint, and then propose a heuristic algorithm to assign spectrum sub-bands. After that, a stepwise plus slice-wise algorithm is proposed to implement the discrete power allocation. Finally, simulation results show that adopting cognitive technology can improve spectrum efficiency of the satellite communication.

  20. Spectrum Allocation for Decentralized Transmission Strategies: Properties of Nash Equilibria

    Directory of Open Access Journals (Sweden)

    Peter von Wrycza

    2009-01-01

    Full Text Available The interaction of two transmit-receive pairs coexisting in the same area and communicating using the same portion of the spectrum is analyzed from a game theoretic perspective. Each pair utilizes a decentralized iterative water-filling scheme to greedily maximize the individual rate. We study the dynamics of such a game and find properties of the resulting Nash equilibria. The region of achievable operating points is characterized for both low- and high-interference systems, and the dependence on the various system parameters is explicitly shown. We derive the region of possible signal space partitioning for the iterative water-filling scheme and show how the individual utility functions can be modified to alter its range. Utilizing global system knowledge, we design a modified game encouraging better operating points in terms of sum rate compared to those obtained using the iterative water-filling algorithm and show how such a game can be imitated in a decentralized noncooperative setting. Although we restrict the analysis to a two player game, analogous concepts can be used to design decentralized algorithms for scenarios with more players. The performance of the modified decentralized game is evaluated and compared to the iterative water-filling algorithm by numerical simulations.

  1. Software architecture design for a dynamic spectrum allocation-enabled cognitive radio testbed

    DEFF Research Database (Denmark)

    Tonelli, Oscar; Berardinelli, Gilberto; Cattoni, Andrea Fabio

    2011-01-01

    The evolution of wireless communications is bringing into reality the dense deployment of femto and local area cells, which represents a challenging scenario for proving the effectiveness of Cognitive Radio (CR) frameworks. In particular the Dynamic Spectrum Allocation (DSA) paradigm aims at solv...

  2. Cognitive radio transmitter with a broadband clean frequency spectrum

    NARCIS (Netherlands)

    Subhan, S.

    2014-01-01

    The tremendous increase in wireless communication over the last few decades has led to a congestion of the radio frequency (RF) spectrum, which is utilized for transmission and reception of information. As suitable RF spectrum is scarce, attempts are being made to use the RF spectrum in a more

  3. Primary user localisation and uplink resource allocation in orthogonal frequency division multiple access cognitive radio systems

    KAUST Repository

    Nam, Haewoon

    2015-05-21

    In cognitive radio networks, secondary users (SUs) can share spectrum with primary users (PUs) under the condition that no interference is caused to the PUs. To evaluate the interference imposed to the PUs, the cognitive systems discussed in the literature usually assume that the channel state information (CSI) of the link from a secondary transmitter to a primary receiver (interference link) is known at the secondary transmitter. However, this assumption may often be impractical in cognitive radio systems, since the PUs need to be oblivious to the presence of the SUs. The authors first discuss PU localisation and then introduce an uplink resource allocation algorithm for orthogonal frequency division multiple access-based cognitive radio systems, where relative location information between primary and SUs is used instead of CSI of the interference link to estimate the interference. Numerical and simulation results show that it is indeed effective to use location information as a part of resource allocation and thus a near-optimal capacity is achieved. © The Institution of Engineering and Technology 2015.

  4. Linear Optimization of Frequency Spectrum Assignments Across System

    Science.gov (United States)

    2016-03-01

    selection tools, frequency allocation, transmission optimization, electromagnetic maneuver warfare, electronic protection, assignment model 15. NUMBER ...Characteristics Modeled ...............................................................29 Table 10.   Antenna Systems Modeled , Number of Systems and...surveillance EW early warning GAMS general algebraic modeling system GHz gigahertz IDE integrated development environment ILP integer linear program

  5. Device for frequency modulation of a laser output spectrum

    Science.gov (United States)

    Beene, J.R.; Bemis, C.E. Jr.

    1984-07-17

    A device is provided for fast frequency modulating the output spectrum of multimode lasers and single frequency lasers that are not actively stabilized. A piezoelectric transducer attached to a laser cavity mirror is driven in an unconventional manner to excite resonance vibration of the tranducer to rapidly, cyclicly change the laser cavity length. The result is a cyclic sweeping of the output wavelength sufficient to fill the gaps in the laser output frequency spectrum. When a laser is used to excite atoms or molecules, complete absorption line coverage is made possible.

  6. Energy-efficient routing, modulation and spectrum allocation in elastic optical networks

    Science.gov (United States)

    Tan, Yanxia; Gu, Rentao; Ji, Yuefeng

    2017-07-01

    With tremendous growth in bandwidth demand, energy consumption problem in elastic optical networks (EONs) becomes a hot topic with wide concern. The sliceable bandwidth-variable transponder in EON, which can transmit/receive multiple optical flows, was recently proposed to improve a transponder's flexibility and save energy. In this paper, energy-efficient routing, modulation and spectrum allocation (EE-RMSA) in EONs with sliceable bandwidth-variable transponder is studied. To decrease the energy consumption, we develop a Mixed Integer Linear Programming (MILP) model with corresponding EE-RMSA algorithm for EONs. The MILP model jointly considers the modulation format and optical grooming in the process of routing and spectrum allocation with the objective of minimizing the energy consumption. With the help of genetic operators, the EE-RMSA algorithm iteratively optimizes the feasible routing path, modulation format and spectrum resources solutions by explore the whole search space. In order to save energy, the optical-layer grooming strategy is designed to transmit the lightpath requests. Finally, simulation results verify that the proposed scheme is able to reduce the energy consumption of the network while maintaining the blocking probability (BP) performance compare with the existing First-Fit-KSP algorithm, Iterative Flipping algorithm and EAMGSP algorithm especially in large network topology. Our results also demonstrate that the proposed EE-RMSA algorithm achieves almost the same performance as MILP on an 8-node network.

  7. An active cooperation-aware spectrum allocation mechanism for body sensor networks.

    Science.gov (United States)

    Jiang, Fu; Guo, Ying; Peng, Jun; Hu, Jiankun

    2015-01-28

    A cognitive radio-based spectrum allocation scheme using an active cooperative-aware mechanism is proposed in this paper. The scheme ensures that the primary user and secondary users cooperate actively for their own benefits. The primary user releases some spectrum resources to secondary users to actively stimulate them to actively join the cooperative transmission of the primary user, and secondary users help the primary user to relay data in return, as well as its self-data transmission at the same time. The Stackelberg game is used to evenly and jointly optimize the utilities of both the primary and secondary users. Simulation results show that the proposed active cooperation-aware mechanism could improve the body sensor network performance.

  8. An Active Cooperation-Aware Spectrum Allocation Mechanism for Body Sensor Networks

    Directory of Open Access Journals (Sweden)

    Fu Jiang

    2015-01-01

    Full Text Available A cognitive radio-based spectrum allocation scheme using an active cooperative-aware mechanism is proposed in this paper. The scheme ensures that the primary user and secondary users cooperate actively for their own benefits. The primary user releases some spectrum resources to secondary users to actively stimulate them to actively join the cooperative transmission of the primary user, and secondary users help the primary user to relay data in return, as well as its self-data transmission at the same time. The Stackelberg game is used to evenly and jointly optimize the utilities of both the primary and secondary users. Simulation results show that the proposed active cooperation-aware mechanism could improve the body sensor network performance.

  9. High-Frequency Axial Fatigue Test Procedures for Spectrum Loading

    Science.gov (United States)

    2016-07-20

    cycle runout limit. PURPOSE 2. To develop the capability to perform High-Frequency (H-F) Spectrum Fatigue tests, an in- house Basic and...response of the test specimen to the command input signal for load cycling . These cycle -by- cycle errors accumulate over the life of the test specimen...fatigue life model. It is expected that the cycle -by- cycle P-V error may vary substantially depending on the load spectrum content, the compensation

  10. Joint Spectrum Sensing and Resource Allocation for OFDM-based Transmission with a Cognitive Relay

    Directory of Open Access Journals (Sweden)

    S. Eman Mahmoodi

    2014-04-01

    Full Text Available In this paper, we investigate the joint spectrum sensing and resource allocation problem to maximize throughput capacity of an OFDM-based cognitive radio link with a cognitive relay. By applying a cognitive relay that uses decode and forward (D&F, we achieve more reliable communications, generating less interference (by needing less transmit power and more diversity gain. In order to account for imperfections in spectrum sensing, the proposed schemes jointly modify energy detector thresholds and allocates transmit powers to all cognitive radio (CR subcarriers, while simultaneously assigning subcarrier pairs for secondary users (SU and the cognitive relay. This problem is cast as a constrained optimization problem with constraints on (1 interference introduced by the SU and the cognitive relay to the PUs; (2 miss-detection and false alarm probabilities and (3 subcarrier pairing for transmission on the SU transmitter and the cognitive relay and (4 minimum Quality of Service (QoS for each CR subcarrier. We propose one optimal and two suboptimal schemes all of which are compared to other schemes in the literature. Simulation results show that the proposed schemes achieve significantly higher throughput than other schemes in the literature for different relay situations.

  11. Extragalactic Peaked-spectrum Radio Sources at Low Frequencies

    Energy Technology Data Exchange (ETDEWEB)

    Callingham, J. R.; Gaensler, B. M.; Sadler, E. M.; Lenc, E. [Sydney Institute for Astronomy (SIfA), School of Physics, The University of Sydney, NSW 2006 (Australia); Ekers, R. D.; Bell, M. E. [CSIRO Astronomy and Space Science (CASS), Marsfield, NSW 2122 (Australia); Line, J. L. B.; Hancock, P. J.; Kapińska, A. D.; McKinley, B.; Procopio, P. [ARC Centre of Excellence for All-Sky Astrophysics (CAASTRO) (Australia); Hurley-Walker, N.; Tingay, S. J.; Franzen, T. M. O.; Morgan, J. [International Centre for Radio Astronomy Research (ICRAR), Curtin University, Bentley, WA 6102 (Australia); Dwarakanath, K. S. [Raman Research Institute (RRI), Bangalore 560080 (India); For, B.-Q. [International Centre for Radio Astronomy Research (ICRAR), The University of Western Australia, Crawley, WA 6009 (Australia); Hindson, L.; Johnston-Hollitt, M. [School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6140 (New Zealand); Offringa, A. R., E-mail: joseph.callingham@sydney.edu.au [Netherlands Institute for Radio Astronomy (ASTRON), Dwingeloo (Netherlands); and others

    2017-02-20

    We present a sample of 1483 sources that display spectral peaks between 72 MHz and 1.4 GHz, selected from the GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey. The GLEAM survey is the widest fractional bandwidth all-sky survey to date, ideal for identifying peaked-spectrum sources at low radio frequencies. Our peaked-spectrum sources are the low-frequency analogs of gigahertz-peaked spectrum (GPS) and compact-steep spectrum (CSS) sources, which have been hypothesized to be the precursors to massive radio galaxies. Our sample more than doubles the number of known peaked-spectrum candidates, and 95% of our sample have a newly characterized spectral peak. We highlight that some GPS sources peaking above 5 GHz have had multiple epochs of nuclear activity, and we demonstrate the possibility of identifying high-redshift ( z > 2) galaxies via steep optically thin spectral indices and low observed peak frequencies. The distribution of the optically thick spectral indices of our sample is consistent with past GPS/CSS samples but with a large dispersion, suggesting that the spectral peak is a product of an inhomogeneous environment that is individualistic. We find no dependence of observed peak frequency with redshift, consistent with the peaked-spectrum sample comprising both local CSS sources and high-redshift GPS sources. The 5 GHz luminosity distribution lacks the brightest GPS and CSS sources of previous samples, implying that a convolution of source evolution and redshift influences the type of peaked-spectrum sources identified below 1 GHz. Finally, we discuss sources with optically thick spectral indices that exceed the synchrotron self-absorption limit.

  12. Frequency-wavenumber spectrum for GATE phase I rainfields

    Science.gov (United States)

    Nakamoto, Shoichiro; Valdes, Juan B.; North, Gerald R.

    1990-01-01

    The oceanic rainfall frequency-wavenumber spectrum and its associated space-time correlation have been evaluated from subsets of GATE phase I data. The records, of a duration of four days, were sampled at 15 minutes intervals in 4 x 4 km grid boxes over a 400 km diameter hexagon. In the low frequencies-low wavenumber region the results coincide with those obtained by using the stochastic model proposed by North and Nakomoto (1989). From the derived spectrum the inherent time and space scales of the stochastic model were determined to be approximately 13 hours and 36 km. The formalism proposed by North and Nakamoto was taken together with the derived spectrum to compute the mean square sampling error due to intermittent visits of a spaceborne sensor.

  13. Application of frequency spectrum analysis in the rotator moving equilibrium

    International Nuclear Information System (INIS)

    Liu Ruilan; Su Guanghui; Shang Zhi; Jia Dounan

    2001-01-01

    The experimental equipment is developed to simulate the rotator vibration. The running state of machine is simulated by using different running conditions. The vibration caused by non-equilibrium mass is analyzed and discussed for first order with focus load. The effective method is found out by using frequency spectrum analysis

  14. Efficient Resource Allocation and Sectorization for Fractional Frequency Reuse (FFR in LTE Femtocell Systems

    Directory of Open Access Journals (Sweden)

    M. T. Kawser

    2015-12-01

    Full Text Available The Fractional Frequency Reuse (FFR is a resource allocation technique that can effectively mitigate inter-cell interference (ICI in LTE based HetNets and it is a promising solution. Various FFR schemes have been suggested to address the challenge of interference in femtocell systems. In this paper, we study the scopes of interference mitigation and capacity improvement. We propose a resource allocation scheme that gradually varies frequency resource share with distance from the eNodeB for both macrocells and femtocells in order to attain better utilization of the resources. This is performed effectively using three layers in the cell. The proposal also employs high number sectors in a cell, low interference and good frequency reuse. Monte-Carlo simulations are performed, which show that the proposed scheme achieves significantly better throughput compared to the existing FFR schemes.

  15. Influences of Fundamental Frequency, Formant Frequencies, Aperiodicity, and Spectrum Level on the Perception of Voice Gender

    Science.gov (United States)

    Skuk, Verena G.; Schweinberger, Stefan R.

    2014-01-01

    Purpose: To determine the relative importance of acoustic parameters (fundamental frequency [F0], formant frequencies [FFs], aperiodicity, and spectrum level [SL]) on voice gender perception, the authors used a novel parameter-morphing approach that, unlike spectral envelope shifting, allows the application of nonuniform scale factors to transform…

  16. Efficient coding schemes with power allocation using space-time-frequency spreading

    Institute of Scientific and Technical Information of China (English)

    Jiang Haining; Luo Hanwen; Tian Jifeng; Song Wentao; Liu Xingzhao

    2006-01-01

    An efficient space-time-frequency (STF) coding strategy for multi-input multi-output orthogonal frequency division multiplexing (MIMO-OFDM) systems is presented for high bit rate data transmission over frequency selective fading channels. The proposed scheme is a new approach to space-time-frequency coded OFDM (COFDM) that combines OFDM with space-time coding, linear precoding and adaptive power allocation to provide higher quality of transmission in terms of the bit error rate performance and power efficiency. In addition to exploiting the maximum diversity gain in frequency, time and space, the proposed scheme enjoys high coding advantages and low-complexity decoding. The significant performance improvement of our design is confirmed by corroborating numerical simulations.

  17. Toroidal coupling and frequency spectrum of tearing modes

    International Nuclear Information System (INIS)

    Edery, D.; Samain, A.

    1989-05-01

    The frequency spectrum of tearing modes is analyzed with the help of a mode coupling model including toroidal effects in the MHD regions and various non linear effects in the resonant layers. In particular it is shown that the sudden damping of the mode rotation and the simultaneous enhancement of the growth rate observed in tokamak, could be explained as a bifurcating solution of the dispersion equation

  18. Frequency Correction for MIRO Chirp Transformation Spectroscopy Spectrum

    Science.gov (United States)

    Lee, Seungwon

    2012-01-01

    This software processes the flyby spectra of the Chirp Transform Spectrometer (CTS) of the Microwave Instrument for Rosetta Orbiter (MIRO). The tool corrects the effect of Doppler shift and local-oscillator (LO) frequency shift during the flyby mode of MIRO operations. The frequency correction for CTS flyby spectra is performed and is integrated with multiple spectra into a high signal-to-noise averaged spectrum at the rest-frame RF frequency. This innovation also generates the 8 molecular line spectra by dividing continuous 4,096-channel CTS spectra. The 8 line spectra can then be readily used for scientific investigations. A spectral line that is at its rest frequency in the frame of the Earth or an asteroid will be observed with a time-varying Doppler shift as seen by MIRO. The frequency shift is toward the higher RF frequencies on approach, and toward lower RF frequencies on departure. The magnitude of the shift depends on the flyby velocity. The result of time-varying Doppler shift is that of an observed spectral line will be seen to move from channel to channel in the CTS spectrometer. The direction (higher or lower frequency) in the spectrometer depends on the spectral line frequency under consideration. In order to analyze the flyby spectra, two steps are required. First, individual spectra must be corrected for the Doppler shift so that individual spectra can be superimposed at the same rest frequency for integration purposes. Second, a correction needs to be applied to the CTS spectra to account for the LO frequency shifts that are applied to asteroid mode.

  19. Frequency Resource Sharing and Allocation Scheme Based on Coalition Formation Game in Hybrid D2D-Cellular Network

    Directory of Open Access Journals (Sweden)

    Qing Ou

    2015-01-01

    Full Text Available A distributed cooperation scheme on frequency resource sharing is proposed to improve the quality of service (QoS in device-to-device (D2D communications underlaying cellular networks. Specifically, we formulate the resource allocation problem as a coalition formation game with transferable utility, in which all users have the incentive to cooperate with some others and form a competitive group to maximize the probability of obtaining their favorite spectrum resources. Taking the cost for coalition formation into account, such as the path loss for data sharing, we prove that the core of the proposed game is empty, which shows the impossibility of grand coalition. Hence, we propose a distributed merge-and-split based coalition formation algorithm based on a new defined Max-Coalition order to effectively solve the coalition game. Compared with the exhaustive search, our algorithm has much lower computer complexity. In addition, we prove that stability and convergence of the proposed algorithm using the concept of a defection function. Finally, the simulation results show that the proposed scheme achieves a suboptimal performance in terms of network sum rate compared with the centralized optimal resource allocation scheme obtained via exhaustive search.

  20. Estimation of average hazardous-event-frequency for allocation of safety-integrity levels

    International Nuclear Information System (INIS)

    Misumi, Y.; Sato, Y.

    1999-01-01

    One of the fundamental concepts of the draft international standard, IEC 61508, is target failure measures to be allocated to Electric/Electronic/Programmable Electronic Safety-Related Systems, i.e. Safety Integrity Levels. The Safety Integrity Levels consist of four discrete probabilistic levels for specifying the safety integrity requirements or the safety functions to be allocated to Electric/Electronic/Programmable Electronic Safety-Related Systems. In order to select the Safety Integrity Levels the draft standard classifies Electric/Electronic/Programmable Electronic Safety-Related Systems into two modes of operation using demand frequencies only. It is not clear which modes of operation should be applied to Electric/Electronic/Programmable Electronic Safety-Related Systems taking into account the demand-state probability and the spurious demand frequency. It is essential for the allocation of Safety Integrity Levels that generic algorithms be derived by involving possible parameters, which make it possible to model the actuality of real systems. The present paper addresses this issue. First of all, the overall system including Electric/Electronic/programmable Electronic Safety-Related Systems is described using a simplified fault-tree. Then, the relationships among demands, demand-states and proof-tests are studied. Overall systems are classified into two groups: a non-demand-state-at-proof-test system which includes both repairable and non-repairable demand states and a constant-demand-frequency system. The new ideas such as a demand-state, spurious demand-state, mean time between detections, rates of d-failure and h-failure, and an h/d ratio are introduced in order to make the Safety Integrity Levels and modes of operation generic and comprehensive. Finally, the overall system is simplified and modeled by fault-trees using Priority-AND gates. At the same time the assumptions for modeling are described. Generic algorithms to estimate hazardous

  1. Delay analysis of a point-to-multipoint spectrum sharing network with CSI based power allocation

    KAUST Repository

    Khan, Fahd Ahmed

    2012-10-01

    In this paper, we analyse the delay performance of a point-to-multipoint cognitive radio network which is sharing the spectrum with a point-to-multipoint primary network. The channel is assumed to be independent but not identically distributed and has Nakagami-m fading. A constraint on the peak transmit power of the secondary user transmitter (SU-Tx) is also considered in addition to the peak interference power constraint. Based on the constraints, a power allocation scheme which requires knowledge of the instantaneous channel state information (CSI) of the interference links is derived. The SU-Tx is assumed to be equipped with a buffer and is modelled using the M/G/1 queueing model. Closed form expressions for the probability distribution function (PDF) and cumulative distribution function (CDF) of the packet transmission time is derived. Using the PDF, the expressions for the moments of transmission time are obtained. In addition, using the moments, the expressions for the performance measures such as the total average waiting time of packets and the average number of packets waiting in the buffer of the SU-Tx are also obtained. Numerical simulations corroborate the theoretical results. © 2012 IEEE.

  2. Resource Allocation with Adaptive Spread Spectrum OFDM Using 2D Spreading for Power Line Communications

    Directory of Open Access Journals (Sweden)

    Baudais Jean-Yves

    2007-01-01

    Full Text Available Bit-loading techniques based on orthogonal frequency division mutiplexing (OFDM are frequently used over wireline channels. In the power line context, channel state information can reasonably be obtained at both transmitter and receiver sides, and adaptive loading can advantageously be carried out. In this paper, we propose to apply loading principles to an spread spectrum OFDM (SS-OFDM waveform which is a multicarrier system using 2D spreading in the time and frequency domains. The presented algorithm handles the subcarriers, spreading codes, bits and energies assignment in order to maximize the data rate and the range of the communication system. The optimization is realized at a target symbol error rate and under spectral mask constraint as usually imposed. The analytical study shows that the merging principle realized by the spreading code improves the rate and the range of the discrete multitone (DMT system in single and multiuser contexts. Simulations have been run over measured power line communication (PLC channel responses and highlight that the proposed system is all the more interesting than the received signal-to-noise ratio (SNR is low.

  3. Resource Allocation with Adaptive Spread Spectrum OFDM Using 2D Spreading for Power Line Communications

    Science.gov (United States)

    Baudais, Jean-Yves; Crussière, Matthieu

    2007-12-01

    Bit-loading techniques based on orthogonal frequency division mutiplexing (OFDM) are frequently used over wireline channels. In the power line context, channel state information can reasonably be obtained at both transmitter and receiver sides, and adaptive loading can advantageously be carried out. In this paper, we propose to apply loading principles to an spread spectrum OFDM (SS-OFDM) waveform which is a multicarrier system using 2D spreading in the time and frequency domains. The presented algorithm handles the subcarriers, spreading codes, bits and energies assignment in order to maximize the data rate and the range of the communication system. The optimization is realized at a target symbol error rate and under spectral mask constraint as usually imposed. The analytical study shows that the merging principle realized by the spreading code improves the rate and the range of the discrete multitone (DMT) system in single and multiuser contexts. Simulations have been run over measured power line communication (PLC) channel responses and highlight that the proposed system is all the more interesting than the received signal-to-noise ratio (SNR) is low.

  4. Frequency spectrum analysis of finger photoplethysmographic waveform variability during haemodialysis.

    Science.gov (United States)

    Javed, Faizan; Middleton, Paul M; Malouf, Philip; Chan, Gregory S H; Savkin, Andrey V; Lovell, Nigel H; Steel, Elizabeth; Mackie, James

    2010-09-01

    This study investigates the peripheral circulatory and autonomic response to volume withdrawal in haemodialysis based on spectral analysis of photoplethysmographic waveform variability (PPGV). Frequency spectrum analysis was performed on the baseline and pulse amplitude variabilities of the finger infrared photoplethysmographic (PPG) waveform and on heart rate variability extracted from the ECG signal collected from 18 kidney failure patients undergoing haemodialysis. Spectral powers were calculated from the low frequency (LF, 0.04-0.145 Hz) and high frequency (HF, 0.145-0.45 Hz) bands. In eight stable fluid overloaded patients (fluid removal of >2 L) not on alpha blockers, progressive reduction in relative blood volume during haemodialysis resulted in significant increase in LF and HF powers of PPG baseline and amplitude variability (P analysis of finger PPGV may provide valuable information on the autonomic vascular response to blood volume reduction in haemodialysis, and can be potentially utilized as a non-invasive tool for assessing peripheral circulatory control during routine dialysis procedure.

  5. A Dynamic Spectrum Allocation Algorithm for a Maritime Cognitive Radio Communication System Based on a Queuing Model

    Directory of Open Access Journals (Sweden)

    Jingbo Zhang

    2017-09-01

    Full Text Available With the rapid development of maritime digital communication, the demand for spectrum resources is increasing, and building a maritime cognitive radio communication system is an effective solution. In this paper, the problem of how to effectively allocate the spectrum for secondary users (SUs with different priorities in a maritime cognitive radio communication system is studied. According to the characteristics of a maritime cognitive radio and existing research about cognitive radio systems, this paper establishes a centralized maritime cognitive radio communication model and creates a simplified queuing model with two queues for the communication model. In the view of the behaviors of SUs and primary users (PUs, we propose a dynamic spectrum allocation (DSA algorithm based on the system status, and analyze it with a two-dimensional Markov chain. Simulation results show that, when different types of SUs have similar arrival rates, the algorithm can vary the priority factor according to the change of users’ status in the system, so as to adjust the channel allocation, decreasing system congestion. The improvement of the algorithm is about 7–26%, and the specific improvement is negatively correlated with the SU arrival rate.

  6. The aggregate site frequency spectrum for comparative population genomic inference.

    Science.gov (United States)

    Xue, Alexander T; Hickerson, Michael J

    2015-12-01

    Understanding how assemblages of species responded to past climate change is a central goal of comparative phylogeography and comparative population genomics, an endeavour that has increasing potential to integrate with community ecology. New sequencing technology now provides the potential to perform complex demographic inference at unprecedented resolution across assemblages of nonmodel species. To this end, we introduce the aggregate site frequency spectrum (aSFS), an expansion of the site frequency spectrum to use single nucleotide polymorphism (SNP) data sets collected from multiple, co-distributed species for assemblage-level demographic inference. We describe how the aSFS is constructed over an arbitrary number of independent population samples and then demonstrate how the aSFS can differentiate various multispecies demographic histories under a wide range of sampling configurations while allowing effective population sizes and expansion magnitudes to vary independently. We subsequently couple the aSFS with a hierarchical approximate Bayesian computation (hABC) framework to estimate degree of temporal synchronicity in expansion times across taxa, including an empirical demonstration with a data set consisting of five populations of the threespine stickleback (Gasterosteus aculeatus). Corroborating what is generally understood about the recent postglacial origins of these populations, the joint aSFS/hABC analysis strongly suggests that the stickleback data are most consistent with synchronous expansion after the Last Glacial Maximum (posterior probability = 0.99). The aSFS will have general application for multilevel statistical frameworks to test models involving assemblages and/or communities, and as large-scale SNP data from nonmodel species become routine, the aSFS expands the potential for powerful next-generation comparative population genomic inference. © 2015 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

  7. Exponential frequency spectrum and Lorentzian pulses in magnetized plasmas

    International Nuclear Information System (INIS)

    Pace, D. C.; Shi, M.; Maggs, J. E.; Morales, G. J.; Carter, T. A.

    2008-01-01

    Two different experiments involving pressure gradients across the confinement magnetic field in a large plasma column are found to exhibit a broadband turbulence that displays an exponential frequency spectrum for frequencies below the ion cyclotron frequency. The exponential feature has been traced to the presence of solitary pulses having a Lorentzian temporal signature. These pulses arise from nonlinear interactions of drift-Alfven waves driven by the pressure gradients. In both experiments the width of the pulses is narrowly distributed resulting in exponential spectra with a single characteristic time scale. The temporal width of the pulses is measured to be a fraction of a period of the drift-Alfven waves. The experiments are performed in the Large Plasma Device (LAPD-U) [W. Gekelman et al., Rev. Sci. Instrum. 62, 2875 (1991)] operated by the Basic Plasma Science Facility at the University of California, Los Angeles. One experiment involves a controlled, pure electron temperature gradient associated with a microscopic (6 mm gradient length) hot electron temperature filament created by the injection a small electron beam embedded in the center of a large, cold magnetized plasma. The other experiment is a macroscopic (3.5 cm gradient length) limiter-edge experiment in which a density gradient is established by inserting a metallic plate at the edge of the nominal plasma column of the LAPD-U. The temperature filament experiment permits a detailed study of the transition from coherent to turbulent behavior and the concomitant change from classical to anomalous transport. In the limiter experiment the turbulence sampled is always fully developed. The similarity of the results in the two experiments strongly suggests a universal feature of pressure-gradient driven turbulence in magnetized plasmas that results in nondiffusive cross-field transport. This may explain previous observations in helical confinement devices, research tokamaks, and arc plasmas.

  8. The Wireless Craze, The Unlimited Bandwidth Myth, The Spectrum Auction Faux Pas, and the Punchline to Ronald Coase's 'Big Joke': An Essay on Airwave Allocation Policy

    OpenAIRE

    Hazlett, Thomas W.

    2001-01-01

    In 1959 the Federal Communications Commission invited economist Ronald Coase to testify about his proposal for market allocation of radio spectrum rights. The FCC's first question: 'Is this all a big joke'' Today, however, leading policy makers, including the current FCC Chair, decry the 'spectrum drought' produced by administrative allocation and call for the creation of private bandwidth markets. This essay examines marketplace trends driving regulators' change of humor, and considers the p...

  9. Resource Allocation in a Frequency Hopping PCS1900/GSM/DCS1800 Type of Network

    DEFF Research Database (Denmark)

    Nielsen, Thomas Toftegaard; Wigard, Jeroen; Michaelsen, Per-Henrik

    1999-01-01

    Resource allocation in a frequency hopping network is even more problematic than in a traditional network. The combined effect from all serving frequencies has to be considered directly in the allocation process. An algorithm doing this for a PCS1900/GSM/DCS1800 type of network is presented. The ....... A graphical visualisation tool has been developed as well. This tool uses a network quality measure tightly linked to the FER rather than the traditional C/I or BER. Using these statistics an increase in network quality is shown...

  10. Research on spectrum broadening covering visible light of a fiber femtosecond optical frequency comb for absolute frequency measurement

    Science.gov (United States)

    Xing, Shuai; Wu, Tengfei; Li, Shuyi; Xia, Chuanqing; Han, Jibo; Zhang, Lei; Zhao, Chunbo

    2018-03-01

    As a bridge connecting microwave frequency and optical frequency, femtosecond laser has important significance in optical frequency measurement. Compared with the traditional Ti-sapphire femtosecond optical frequency comb, with the advantages of compact structure, strong anti-interference ability and low cost, the fiber femtosecond optical frequency comb has a wider application prospect. An experiment of spectrum broadening in a highly nonlinear photonic crystal fiber pumped by an Er-fiber mode-locked femtosecond laser is studied in this paper. Based on optical amplification and frequency doubling, the central wavelength of the output spectrum is 780nm and the average power is 232mW. With the femtosecond pulses coupled into two different photonic crystal fibers, the coverage of visible spectrum is up to 500nm-960nm. The spectral shape and width can be optimized by changing the polarization state for satisfying the requirments of different optical frequencies measurement.

  11. Delay analysis of a point-to-multipoint spectrum sharing network with CSI based power allocation

    KAUST Repository

    Khan, Fahd Ahmed; Tourki, Kamel; Alouini, Mohamed-Slim; Qaraqe, Khalid A.

    2012-01-01

    and has Nakagami-m fading. A constraint on the peak transmit power of the secondary user transmitter (SU-Tx) is also considered in addition to the peak interference power constraint. Based on the constraints, a power allocation scheme which requires

  12. Effect of water depth on wind-wave frequency spectrum I. Spectral form

    Science.gov (United States)

    Wen, Sheng-Chang; Guan, Chang-Long; Sun, Shi-Cai; Wu, Ke-Jian; Zhang, Da-Cuo

    1996-06-01

    Wen et al's method developed to obtain wind-wave frequency spectrum in deep water was used to derive the spectrum in finite depth water. The spectrum S(ω) (ω being angular frequency) when normalized with the zeroth moment m 0 and peak frequency {ie97-1}, contains in addition to the peakness factor {ie97-2} a depth parameter η=(2π m o)1/2/ d ( d being water depth), so the spectrum behavior can be studied for different wave growth stages and water depths.

  13. Implementation Aspects of a Flexible Frequency Spectrum Usage Algorithm for Cognitive OFDM Systems

    DEFF Research Database (Denmark)

    Sacchi, Claudio; Tonelli, Oscar; Cattoni, Andrea Fabio

    2011-01-01

    time on a shared spectrum chunk, emphasizes the role of resource allocation as a critical system design issue. This work is aimed at analyzing the practical issues related to the Software Defined Radio (SDR)-based implementation of a dynamic spectrum allocation algorithm, designed for OFDM...... on a Xilinx ML506 development board is performed. The main novelty proposed in this paper consists in the SDR-based implementation of a computationally-sustainable resource allocation algorithm for FSU on low-cost commercial FPGA platforms. The proposed implementation is competitive with respect to other ones...... on a Virtex 5 FPGA. Experimental results will illustrate that the selected core functionalities are effectively implementable with around 3% or less of the total FPGA computing resources....

  14. Attention is allocated closely ahead of the target during smooth pursuit eye movements: Evidence from EEG frequency tagging.

    Science.gov (United States)

    Chen, Jing; Valsecchi, Matteo; Gegenfurtner, Karl R

    2017-07-28

    It is under debate whether attention during smooth pursuit is centered right on the pursuit target or allocated preferentially ahead of it. Attentional deployment was previously probed using a secondary task, which might have altered attention allocation and led to inconsistent findings. We measured frequency-tagged steady-state visual evoked potentials (SSVEP) to measure attention allocation in the absence of any secondary probing task. The observers pursued a moving dot while stimuli flickering at different frequencies were presented at various locations ahead or behind the pursuit target. We observed a significant increase in EEG power at the flicker frequency of the stimulus in front of the pursuit target, compared to the frequency of the stimulus behind. When testing many different locations, we found that the enhancement was detectable up to about 1.5° ahead during pursuit, but vanished by 3.5°. In a control condition using attentional cueing during fixation, we did observe an enhanced EEG response to stimuli at this eccentricity, indicating that the focus of attention during pursuit is narrower than allowed for by the resolution of the attentional system. In a third experiment, we ruled out the possibility that the SSVEP enhancement was a byproduct of the catch-up saccades occurring during pursuit. Overall, we showed that attention is on average allocated ahead of the pursuit target during smooth pursuit. EEG frequency tagging seems to be a powerful technique that allows for the investigation of attention/perception implicitly when an overt task would be confounding. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. An automatic method to determine cutoff frequency based on image power spectrum

    International Nuclear Information System (INIS)

    Beis, J.S.; Vancouver Hospital and Health Sciences Center, British Columbia; Celler, A.; Barney, J.S.

    1995-01-01

    The authors present an algorithm for automatically choosing filter cutoff frequency (F c ) using the power spectrum of the projections. The method is based on the assumption that the expectation of the image power spectrum is the sum of the expectation of the blurred object power spectrum (dominant at low frequencies) plus a constant value due to Poisson noise. By considering the discrete components of the noise-dominated high-frequency spectrum as a Gaussian distribution N(μ,σ), the Student t-test determines F c as the highest frequency for which the image frequency components are unlikely to be drawn from N (μ,σ). The method is general and can be applied to any filter. In this work, the authors tested the approach using the Metz restoration filter on simulated, phantom, and patient data with good results. Quantitative performance of the technique was evaluated by plotting recovery coefficient (RC) versus NMSE of reconstructed images

  16. Implementation of an Optical-Wireless Network with Spectrum Sensing and Dynamic Resource Allocation Using Optically Controlled Reconfigurable Antennas

    Directory of Open Access Journals (Sweden)

    E. Raimundo-Neto

    2014-01-01

    Full Text Available This work proposes the concept and reports the implementation of an adaptive and cognitive radio over fiber architecture. It is aimed at dealing with the new demands for convergent networks by means of simultaneously providing the functionalities of multiband radiofrequency spectrum sensing, dynamic resource allocation, and centralized processing capability, as well as the use of optically controlled reconfigurable antennas and radio over fiber technology. The performance of this novel and innovative architecture has been evaluated in a geographically distributed optical-wireless network under real conditions and for different fiber lengths. Experimental results demonstrate reach extension of more than 40 times and an enhancement of more than 30 dB in the carrier to interference plus noise ratio parameter.

  17. The Real-time Frequency Spectrum Analysis of Neutron Pulse Signal Series

    International Nuclear Information System (INIS)

    Tang Yuelin; Ren Yong; Wei Biao; Feng Peng; Mi Deling; Pan Yingjun; Li Jiansheng; Ye Cenming

    2009-01-01

    The frequency spectrum analysis of neutron pulse signal is a very important method in nuclear stochastic signal processing Focused on the special '0' and '1' of neutron pulse signal series, this paper proposes new rotation-table and realizes a real-time frequency spectrum algorithm under 1G Hz sample rate based on PC with add, address and SSE. The numerical experimental results show that under the count rate of 3X10 6 s -1 , this algorithm is superior to FFTW in time-consumption and can meet the real-time requirement of frequency spectrum analysis. (authors)

  18. Frequency spectrum analysis of 252Cf neutron source based on LabVIEW

    International Nuclear Information System (INIS)

    Mi Deling; Li Pengcheng

    2011-01-01

    The frequency spectrum analysis of 252 Cf Neutron source is an extremely important method in nuclear stochastic signal processing. Focused on the special '0' and '1' structure of neutron pulse series, this paper proposes a fast-correlation algorithm to improve the computational rate of the spectrum analysis system. And the multi-core processor technology is employed as well as multi-threaded programming techniques of LabVIEW to construct frequency spectrum analysis system of 252 Cf neutron source based on LabVIEW. It not only obtains the auto-correlation and cross correlation results, but also auto-power spectrum,cross-power spectrum and ratio of spectral density. The results show that: analysis tools based on LabVIEW improve the fast auto-correlation and cross correlation code operating efficiency about by 25% to 35%, also verify the feasibility of using LabVIEW for spectrum analysis. (authors)

  19. Normative evaluations and frequency expectations regarding positive versus negative outcome allocations between groups

    NARCIS (Netherlands)

    Blanz, M; Mummendey, A; Otten, S

    1997-01-01

    Data from several recent studies consistently show a positive-negative asymmetry in social discrimination: within a minimal social situation tendencies cowards ingroup favouritism which usually appear in allocations of positively valenced resources are absent in the domain of negatively valenced

  20. Spectrum monitoring: Radio Frequency Interferences (RFI) profile for ...

    African Journals Online (AJOL)

    It was crucial to monitor the Radio Frequency Interference (RFI) in order to conduct the radio astronomical research with very minimum RFI. These RFI will be distorted the astronomical data. In this work, we have investigated the RFI strength (dBm) and presenting on how the nearby RFI affect to the OH lines window (1600 ...

  1. 79 GHz UWB automotive short range radar – Spectrum allocation and technology trends

    Directory of Open Access Journals (Sweden)

    H.-L. Bloecher

    2009-05-01

    Full Text Available Automotive UWB (Ultra-Wideband short range radar (SSR is on the market as a key technology for novel comfort and safety systems. SiGe based 79 GHz UWB SRR will be a definite candidate for the long term substitution of the 24 GHz UWB SRR. This paper will give an overview of the finished BMBF joint project KOKON and the recently started successing project RoCC, which concentrate on the development of this technology and sensor demonstrators. In both projects, the responsibilities of Daimler AG deal with application based sensor specification, test and evaluation of realized sensor demonstrators. Recent UWB SRR frequency regulation approaches and activitites will be introduced. Furthermore, some first results of Daimler activities within RoCC will be presented, dealing with the packaging and operation of these sensors within the complex car environment.

  2. Primary user localisation and uplink resource allocation in orthogonal frequency division multiple access cognitive radio systems

    KAUST Repository

    Nam, Haewoon; Saeed, Nasir; Ben Ghorbel, Mahdi; Alouini, Mohamed-Slim

    2015-01-01

    In cognitive radio networks, secondary users (SUs) can share spectrum with primary users (PUs) under the condition that no interference is caused to the PUs. To evaluate the interference imposed to the PUs, the cognitive systems discussed

  3. 5G Spectrum Sharing

    OpenAIRE

    Nekovee, Maziar; Rudd, Richard

    2017-01-01

    In this paper an overview is given of the current status of 5G industry standards, spectrum allocation and use cases, followed by initial investigations of new opportunities for spectrum sharing in 5G using cognitive radio techniques, considering both licensed and unlicensed scenarios. A particular attention is given to sharing millimeter-wave frequencies, which are of prominent importance for 5G.

  4. Evaluation of elastic constants of materials using the frequency spectrum

    International Nuclear Information System (INIS)

    Silva Neto, Ramiro J. da; Baroni, Douglas B.; Bittencourt, Marcelo de S.Q.

    2015-01-01

    The characterization of materials made with the support of non-destructive techniques has great importance in industrial applications. The ultrasonic techniques are distinguished by good resolution to measure small variations of wave velocities as a result of changes in the character suffered by a particular material. In general these ultrasonic techniques are studied in the time domain, which represents an experimental difficulties when thin materials are analyzed, as well as to attenuate the ultrasonic signal drastically. An ultrasonic technique that uses the frequency domain is used in this study aiming to provide good time measurements to calculate the elastic constants of the first order in an aluminum alloy 6351. With the aid of a statistical approach was possible to have good results of tests performed when compared by a time domain technique already well explored in Ultrasound works produced in the Nuclear Engineering Institute Laboratory (LABUS / IEN) and also presented in most of the package, in good agreement with the theoretical model established in literature and used to validate the experiment, which was found in the results with good approximation. The relevance of this work in the nuclear area is associated with the interest to know the mechanical properties of structural components of the nuclear industry, which is currently studied as a rule, resorting to the computer simulations or previously during the operation of the system. (author)

  5. Evaluation of elastic constants of materials using the frequency spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Silva Neto, Ramiro J. da; Baroni, Douglas B.; Bittencourt, Marcelo de S.Q., E-mail: ramirobd@gmail.com [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Departamento de Materiais Nucleares. Laboratorio de Ultrassom

    2015-07-01

    The characterization of materials made with the support of non-destructive techniques has great importance in industrial applications. The ultrasonic techniques are distinguished by good resolution to measure small variations of wave velocities as a result of changes in the character suffered by a particular material. In general these ultrasonic techniques are studied in the time domain, which represents an experimental difficulties when thin materials are analyzed, as well as to attenuate the ultrasonic signal drastically. An ultrasonic technique that uses the frequency domain is used in this study aiming to provide good time measurements to calculate the elastic constants of the first order in an aluminum alloy 6351. With the aid of a statistical approach was possible to have good results of tests performed when compared by a time domain technique already well explored in Ultrasound works produced in the Nuclear Engineering Institute Laboratory (LABUS / IEN) and also presented in most of the package, in good agreement with the theoretical model established in literature and used to validate the experiment, which was found in the results with good approximation. The relevance of this work in the nuclear area is associated with the interest to know the mechanical properties of structural components of the nuclear industry, which is currently studied as a rule, resorting to the computer simulations or previously during the operation of the system. (author)

  6. Spectrum Control through Discrete Frequency Diffraction in the Presence of Photonic Gauge Potentials

    Science.gov (United States)

    Qin, Chengzhi; Zhou, Feng; Peng, Yugui; Sounas, Dimitrios; Zhu, Xuefeng; Wang, Bing; Dong, Jianji; Zhang, Xinliang; Alù; , Andrea; Lu, Peixiang

    2018-03-01

    By using optical phase modulators in a fiber-optical circuit, we theoretically and experimentally demonstrate large control over the spectrum of an impinging signal, which may evolve analogously to discrete diffraction in spatial waveguide arrays. The modulation phase acts as a photonic gauge potential in the frequency dimension, realizing efficient control of the central frequency and bandwidth of frequency combs. We experimentally achieve a 50 GHz frequency shift and threefold bandwidth expansion of an impinging comb, as well as the frequency analogue of various refraction phenomena, including negative refraction and perfect focusing in the frequency domain, both for discrete and continuous incident spectra. Our study paves a promising way towards versatile frequency management for optical communications and signal processing using time modulation schemes.

  7. Frequency spectrum might act as communication code between retina and visual cortex I

    Directory of Open Access Journals (Sweden)

    Xu Yang

    2015-12-01

    Full Text Available AIM: To explore changes and possible communication relationship of local potential signals recorded simultaneously from retina and visual cortex I (V1. METHODS: Fourteen C57BL/6J mice were measured with pattern electroretinogram (PERG and pattern visually evoked potential (PVEP and fast Fourier transform has been used to analyze the frequency components of those signals. RESULTS: The amplitude of PERG and PVEP was measured at about 36.7 µV and 112.5 µV respectively and the dominant frequency of PERG and PVEP, however, stay unchanged and both signals do not have second, or otherwise, harmonic generation. CONCLUSION: The results suggested that retina encodes visual information in the way of frequency spectrum and then transfers it to primary visual cortex. The primary visual cortex accepts and deciphers the input visual information coded from retina. Frequency spectrum may act as communication code between retina and V1.

  8. Frequency spectrum might act as communication code between retina and visual cortex I.

    Science.gov (United States)

    Yang, Xu; Gong, Bo; Lu, Jian-Wei

    2015-01-01

    To explore changes and possible communication relationship of local potential signals recorded simultaneously from retina and visual cortex I (V1). Fourteen C57BL/6J mice were measured with pattern electroretinogram (PERG) and pattern visually evoked potential (PVEP) and fast Fourier transform has been used to analyze the frequency components of those signals. The amplitude of PERG and PVEP was measured at about 36.7 µV and 112.5 µV respectively and the dominant frequency of PERG and PVEP, however, stay unchanged and both signals do not have second, or otherwise, harmonic generation. The results suggested that retina encodes visual information in the way of frequency spectrum and then transfers it to primary visual cortex. The primary visual cortex accepts and deciphers the input visual information coded from retina. Frequency spectrum may act as communication code between retina and V1.

  9. The yule approximation for the site frequency spectrum after a selective sweep.

    Directory of Open Access Journals (Sweden)

    Sebastian Bossert

    Full Text Available In the area of evolutionary theory, a key question is which portions of the genome of a species are targets of natural selection. Genetic hitchhiking is a theoretical concept that has helped to identify various such targets in natural populations. In the presence of recombination, a severe reduction in sequence diversity is expected around a strongly beneficial allele. The site frequency spectrum is an important tool in genome scans for selection and is composed of the numbers S(1,...,S(n-1, where S(k is the number of single nucleotide polymorphisms (SNPs present in k from n individuals. Previous work has shown that both the number of low- and high-frequency variants are elevated relative to neutral evolution when a strongly beneficial allele fixes. Here, we follow a recent investigation of genetic hitchhiking using a marked Yule process to obtain an analytical prediction of the site frequency spectrum in a panmictic population at the time of fixation of a highly beneficial mutation. We combine standard results from the neutral case with the effects of a selective sweep. As simulations show, the resulting formula produces predictions that are more accurate than previous approaches for the whole frequency spectrum. In particular, the formula correctly predicts the elevation of low- and high-frequency variants and is significantly more accurate than previously derived formulas for intermediate frequency variants.

  10. Eavesdropping-aware routing and spectrum allocation based on multi-flow virtual concatenation for confidential information service in elastic optical networks

    Science.gov (United States)

    Bai, Wei; Yang, Hui; Yu, Ao; Xiao, Hongyun; He, Linkuan; Feng, Lei; Zhang, Jie

    2018-01-01

    The leakage of confidential information is one of important issues in the network security area. Elastic Optical Networks (EON) as a promising technology in the optical transport network is under threat from eavesdropping attacks. It is a great demand to support confidential information service (CIS) and design efficient security strategy against the eavesdropping attacks. In this paper, we propose a solution to cope with the eavesdropping attacks in routing and spectrum allocation. Firstly, we introduce probability theory to describe eavesdropping issue and achieve awareness of eavesdropping attacks. Then we propose an eavesdropping-aware routing and spectrum allocation (ES-RSA) algorithm to guarantee information security. For further improving security and network performance, we employ multi-flow virtual concatenation (MFVC) and propose an eavesdropping-aware MFVC-based secure routing and spectrum allocation (MES-RSA) algorithm. The presented simulation results show that the proposed two RSA algorithms can both achieve greater security against the eavesdropping attacks and MES-RSA can also improve the network performance efficiently.

  11. Frequency and spectrum of mutations induced by gamma irradiation in single, double and triple dwarf wheats

    International Nuclear Information System (INIS)

    Dhonukshe, B.L.

    1981-01-01

    Induced mutation studies were carried with three dwarf wheat varieties viz., ''Sonalika'', ''Chhoti Lerma'' and ''Hira'', considered to be single, double and trible dwarfs, respectively. Gamma-rays were used as a source of irradiation. Frequency of chlorophyll mutations were comparatively low and the spectrum was narrow. Chlorophyll mutations were altogether absent in the variety ''Sonalika''. A very wide spectrum of viable mutations affecting stem, leaf, ear growth habit, maturity and fertility characteristics was observed in the M 2 . The cumulative frequency of all the mutants together was quite high, which varied with the varieties. There were varietal differences in the composition and width of the spectrum induced by gamma-rays. The dwarf mutants having desirable leaf and spike characters were isolated in all the three varieties. (author)

  12. Image enhancement of x-ray microscope using frequency spectrum analysis

    International Nuclear Information System (INIS)

    Li Wenjie; Chen Jie; Tian Jinping; Zhang Xiaobo; Liu Gang; Tian Yangchao; Liu Yijin; Wu Ziyu

    2009-01-01

    We demonstrate a new method for x-ray microscope image enhancement using frequency spectrum analysis. Fine sample characteristics are well enhanced with homogeneous visibility and better contrast from single image. This method is easy to implement and really helps to improve the quality of image taken by our imaging system.

  13. Image enhancement of x-ray microscope using frequency spectrum analysis

    Energy Technology Data Exchange (ETDEWEB)

    Li Wenjie; Chen Jie; Tian Jinping; Zhang Xiaobo; Liu Gang; Tian Yangchao [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029 (China); Liu Yijin; Wu Ziyu, E-mail: wuzy@ihep.ac.c, E-mail: ychtian@ustc.edu.c [Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049 (China)

    2009-09-01

    We demonstrate a new method for x-ray microscope image enhancement using frequency spectrum analysis. Fine sample characteristics are well enhanced with homogeneous visibility and better contrast from single image. This method is easy to implement and really helps to improve the quality of image taken by our imaging system.

  14. Integrated Common Radio Resource Management with Spectrum Aggregation over Non-Contiguous Frequency Bands

    DEFF Research Database (Denmark)

    Cabral, Orlando; Meucci, Filippo; Mihovska, Albena D.

    2011-01-01

    This paper proposes an integrated Common Radio Resource Management (iCRRM). The iCRRM performs classic CRRM functionalities jointly with Spectrum Aggregation (SA), being able to switch users between non-contiguous frequency bands. The SA scheduling is obtained with an optimised General Multi...

  15. High-Frequency EEG Variations in Children with Autism Spectrum Disorder during Human Faces Visualization

    Directory of Open Access Journals (Sweden)

    Celina A. Reis Paula

    2017-01-01

    Full Text Available Autism spectrum disorder (ASD is a neuropsychiatric disorder characterized by the impairment in the social reciprocity, interaction/language, and behavior, with stereotypes and signs of sensory function deficits. Electroencephalography (EEG is a well-established and noninvasive tool for neurophysiological characterization and monitoring of the brain electrical activity, able to identify abnormalities related to frequency range, connectivity, and lateralization of brain functions. This research aims to evidence quantitative differences in the frequency spectrum pattern between EEG signals of children with and without ASD during visualization of human faces in three different expressions: neutral, happy, and angry. Quantitative clinical evaluations, neuropsychological evaluation, and EEG of children with and without ASD were analyzed paired by age and gender. The results showed stronger activation in higher frequencies (above 30 Hz in frontal, central, parietal, and occipital regions in the ASD group. This pattern of activation may correlate with developmental characteristics in the children with ASD.

  16. High-frequency asymptotics of the emission spectrum of moving charged particles in classical electrodynamics

    International Nuclear Information System (INIS)

    Abbasov, I.I.; Bolotovskij, B.M.; Davydov, V.A.

    1986-01-01

    Electromagnetic radiation appears as a result of a charged particle movement in free space and also in heterogeneous and non-stationary medium. The radiation spectrum depends on the charged particle motion law, as well as on the law of the medium property chage in space and time. The asymptotics of radiation spectrum, i.e. behaviour of spectral intensity at high frequencies, is studied. It is shown that if a charged particle moves along smooth trajectory or if the change in the medium properties takes place accordng to the law described by a smooth function, the radiation spectrum at high frequencies decreases according to exponential law. Thus, radiation spectrum of a charged particle moving along a smooth trajectory in the medium with gradual heterogeneity and (or) instability is rapidly cut, starting from a certain frequency value. The smooth trajectory means that the charge moves according to the law r = r(t), where vector-function r(t) is continuous with all its derivatives. In much the same way the medium with gradual heterogeneities (or with gradual instability) is described by the functions which are continuous with all their derivatives of any order. The method permitting to determine the upper boundary of radiation spectra is presented

  17. Simulation of particle diffusion in a spectrum of electrostatic turbulence. Low frequency Bohm or percolation scaling

    International Nuclear Information System (INIS)

    Reuss, J.D.; Misguich, J.H.

    1996-02-01

    An important point for turbulent transport consists in determining the scaling law for the diffusion coefficient D due to electrostatic turbulence. It is well-known that for weak amplitudes or large frequencies, the reduced diffusion coefficient has a quasi-linear like (or gyro-Bohm like) scaling, while for large amplitudes or small frequencies it has been traditionally believed that the scaling is Bohm-like. The aim of this work consists to test this prediction for a given realistic model. This problem is studied by direct simulation of particle trajectories. Guiding centre diffusion in a spectrum of electrostatic turbulence is computed for test particles in a model spectrum, by means of a new parallelized code RADIGUET 2. The results indicate a continuous transition for large amplitudes toward a value which is compatible with the Isichenko percolation prediction. (author)

  18. On the nature of dissipative Timoshenko systems at light of the second spectrum of frequency

    Science.gov (United States)

    Almeida Júnior, D. S.; Ramos, A. J. A.

    2017-12-01

    In the present work, we prove that there exists a relation between a physical inconsistence known as second spectrum of frequency or non-physical spectrum and the exponential decay of a dissipative Timoshenko system where the damping mechanism acts on angle rotation. The so-called second spectrum is addressed into stabilization scenario and, in particular, we show that the second spectrum of the classical Timoshenko model can be truncated by taking a damping mechanism. Also, we show that dissipative Timoshenko type systems which are free of the second spectrum [based on important physical and historical observations made by Elishakoff (Advances mathematical modeling and experimental methods for materials and structures, solid mechanics and its applications, Springer, Berlin, pp 249-254, 2010), Elishakoff et al. (ASME Am Soc Mech Eng Appl Mech Rev 67(6):1-11 2015) and Elishakoff et al. (Int J Solids Struct 109:143-151, 2017)] are exponential stable for any values of the coefficients of system. In this direction, we provide physical explanations why weakly dissipative Timoshenko systems decay exponentially according to equality between velocity of wave propagation as proved in pioneering works by Soufyane (C R Acad Sci 328(8):731-734, 1999) and also by Muñoz Rivera and Racke (Discrete Contin Dyn Syst B 9:1625-1639, 2003). Therefore, the second spectrum of the classical Timoshenko beam model plays an important role in explaining some results on exponential decay and our investigations suggest to pay attention to the eventual consequences of this spectrum on stabilization setting for dissipative Timoshenko type systems.

  19. A measurement of the low frequency spectrum of the cosmic microwave background radiation

    International Nuclear Information System (INIS)

    Levin, S.M.

    1987-04-01

    As part of a larger effort to measure the spectrum of the Cosmic Background Radiation (CBR) at low frequencies, the intensity of the CBR has been measured at a frequency of 1.410 GHz. The measurement was made by comparing the power received from the sky with the power received from a specially designed cooled calibration target with known properties. Sources of radiation other than the CBR were then identified and subtracted to calculate the antenna temperature of the CBR at 1.410 GHz. The instrument used to measure the CBR was a total-power microwave radiometer with a 25 MHz bandwidth centered at 1.410 GHz. The radiometer had a noise temperature of 80 K, and sufficient data were taken that radiometer noise did not contribute significantly to the total measurement error. The sources of error were predominantly systematic in nature, and the largest error was due to uncertainty in the reflection characteristics of the cold-load calibrator. Identification and subtraction of signals from the Galaxy (0.7 K) and the Earth's atmosphere (0.8 K) were also significant parts of the data reduction and error analysis. The brightness temperature of the Cosmic Background Radiation at 1.410 GHz is 222. +- 0.55 Kelvin. The spectrum of the CBR, as determined by this measurement and other published results, is consistent with a blackbody spectrum of temperature 2.741 +- 0.016. Constraints on the amount by which the CBR spectrum deviates from Planck spectrum are used to place limits on energy releases early in the history of the universe. 55 refs., 25 figs., 8 tabs

  20. [Detection of endotoxins of Gram-negative bacteria on the basis of electromagnetic radiation frequency spectrum].

    Science.gov (United States)

    Likhoded, V G; Kuleshova, N V; Sergieva, N V; Konev, Iu V; Trubnikova, I A; Sudzhian, E V

    2007-01-01

    Method of Gram-negative bacteria endotoxins detection on the basis of their own spectrum of electromagnetic radiation frequency was developed. Frequency spectrum typical for chemotype Re glycolipid, which is a part of lypopolysaccharides in the majority of Gram-negative bacteria, was used. Two devices--"Mini- Expert-DT" (manufactured by IMEDIS, Moscow) and "Bicom" (manufactured by Regumed, Germany)--were used as generators of electromagnetic radiation. Detection of endotoxin using these devices was performed by electropuncture vegetative resonance test. Immunoenzyme reaction with antibodies to chemotype Re glycolipid was used during analysis of preparations for assessment of resonance-frequency method specificity. The study showed that resonance-frequency method can detect lypopolysaccharides of different enterobacteria in quantities up to 0.1 pg as well as bacteria which contain lypopolysaccharides. At the same time, this method does not detect such bacteria as Staphylococcus aureus, Bifidobacterium spp., Lactobacillus spp., and Candida albicans. The method does not require preliminary processing of blood samples and can be used for diagnostics of endotoxinemia, and detection of endotoxins in blood samples or injection solutions.

  1. Measured wavenumber: frequency spectrum associated with acoustic and aerodynamic wall pressure fluctuations.

    Science.gov (United States)

    Arguillat, Blandine; Ricot, Denis; Bailly, Christophe; Robert, Gilles

    2010-10-01

    Direct measurements of the wavenumber-frequency spectrum of wall pressure fluctuations beneath a turbulent plane channel flow have been performed in an anechoic wind tunnel. A rotative array has been designed that allows the measurement of a complete map, 63×63 measuring points, of cross-power spectral densities over a large area. An original post-processing has been developed to separate the acoustic and the aerodynamic exciting loadings by transforming space-frequency data into wavenumber-frequency spectra. The acoustic part has also been estimated from a simple Corcos-like model including the contribution of a diffuse sound field. The measured acoustic contribution to the surface pressure fluctuations is 5% of the measured aerodynamic surface pressure fluctuations for a velocity and boundary layer thickness relevant for automotive interior noise applications. This shows that for aerodynamically induced car interior noise, both contributions to the surface pressure fluctuations on car windows have to be taken into account.

  2. Economic aspects of spectrum management

    Science.gov (United States)

    Stibolt, R. D.

    1979-01-01

    Problems associated with the allocation of the radio frequency spectrum are addressed. It is observed that the current method very likely does not allocate the resource to those most valuing its use. Ecomonic criteria by which the effectiveness of resource allocation schemes can be judged are set forth and some thoughts on traditional objections to implementation of market characteristics into frequency allocation are offered. The problem of dividing orbit and spectrum between two satellite services sharing the same band but having significantly different system characteristics is discussed. The problem is compounded by the likelihood that one service will commence operation much sooner than the other. Some alternative schemes are offered that, within proper international constraints, could achieve a desired flexibility in the division of orbit and frequency between the two services domestically over the next several years.

  3. Peak alpha frequency is a neural marker of cognitive function across the autism spectrum.

    Science.gov (United States)

    Dickinson, Abigail; DiStefano, Charlotte; Senturk, Damla; Jeste, Shafali Spurling

    2018-03-01

    Cognitive function varies substantially and serves as a key predictor of outcome and response to intervention in autism spectrum disorder (ASD), yet we know little about the neurobiological mechanisms that underlie cognitive function in children with ASD. The dynamics of neuronal oscillations in the alpha range (6-12 Hz) are associated with cognition in typical development. Peak alpha frequency is also highly sensitive to developmental changes in neural networks, which underlie cognitive function, and therefore, it holds promise as a developmentally sensitive neural marker of cognitive function in ASD. Here, we measured peak alpha band frequency under a task-free condition in a heterogeneous sample of children with ASD (N = 59) and age-matched typically developing (TD) children (N = 38). At a group level, peak alpha frequency was decreased in ASD compared to TD children. Moreover, within the ASD group, peak alpha frequency correlated strongly with non-verbal cognition. As peak alpha frequency reflects the integrity of neural networks, our results suggest that deviations in network development may underlie cognitive function in individuals with ASD. By shedding light on the neurobiological correlates of cognitive function in ASD, our findings lay the groundwork for considering peak alpha frequency as a useful biomarker of cognitive function within this population which, in turn, will facilitate investigations of early markers of cognitive impairment and predictors of outcome in high risk infants. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  4. Statistical Analysis of Solar PV Power Frequency Spectrum for Optimal Employment of Building Loads

    Energy Technology Data Exchange (ETDEWEB)

    Olama, Mohammed M [ORNL; Sharma, Isha [ORNL; Kuruganti, Teja [ORNL; Fugate, David L [ORNL

    2017-01-01

    In this paper, a statistical analysis of the frequency spectrum of solar photovoltaic (PV) power output is conducted. This analysis quantifies the frequency content that can be used for purposes such as developing optimal employment of building loads and distributed energy resources. One year of solar PV power output data was collected and analyzed using one-second resolution to find ideal bounds and levels for the different frequency components. The annual, seasonal, and monthly statistics of the PV frequency content are computed and illustrated in boxplot format. To examine the compatibility of building loads for PV consumption, a spectral analysis of building loads such as Heating, Ventilation and Air-Conditioning (HVAC) units and water heaters was performed. This defined the bandwidth over which these devices can operate. Results show that nearly all of the PV output (about 98%) is contained within frequencies lower than 1 mHz (equivalent to ~15 min), which is compatible for consumption with local building loads such as HVAC units and water heaters. Medium frequencies in the range of ~15 min to ~1 min are likely to be suitable for consumption by fan equipment of variable air volume HVAC systems that have time constants in the range of few seconds to few minutes. This study indicates that most of the PV generation can be consumed by building loads with the help of proper control strategies, thereby reducing impact on the grid and the size of storage systems.

  5. Induced mutations in chickpea (Cicer arietinum L.) II. frequency and spectrum of chlorophyll mutations

    International Nuclear Information System (INIS)

    Kharkwal, M.C.

    1998-01-01

    A comparative study of frequency and spectrum of chlorophyll mutations induced by two physical (gamma rays, fast neutrons) and two chemical mutagens (NMU, EMS) in relation to the effects in M1 plants and induction of mutations in M2 was made in four chickpea (Cicer arietinum L.) varieties, two desi (G 130 & H 214) one Kabuli (C 104) and one green seeded (L 345). The treatments included three doses each of gamma rays (400, 500 & 600 Gy) and fast neutrons (5, 10 & 15 Gy) and two concentrations with two different durations of two chemical mutagens, NMU [0.01% (20h), & 0.02% (8h)] and EMS [0.1% (20h) & 0.2% (8h)]. The frequencies and spectrum of three different kinds of induced chlorophyll mutations in the order albina (43.5%), chlorina (27.3%) and xantha (24.2%) were recorded. Chemical mutagens were found to be efficient in inducing chlorophyll mutations in chickpea. Highest frequency of mutations was observed in green seeded var. L 345 (83% of M1 families and 19.9/1000 M2 plants). Kabuli var. C 104 was least responsive for chlorophyll mutations

  6. Influence of the Spatial Dimensions of Ultrasonic Transducers on the Frequency Spectrum of Guided Waves.

    Science.gov (United States)

    Samaitis, Vykintas; Mažeika, Liudas

    2017-08-08

    Ultrasonic guided wave (UGW)-based condition monitoring has shown great promise in detecting, localizing, and characterizing damage in complex systems. However, the application of guided waves for damage detection is challenging due to the existence of multiple modes and dispersion. This results in distorted wave packets with limited resolution and the interference of multiple reflected modes. To develop reliable inspection systems, either the transducers have to be optimized to generate a desired single mode of guided waves with known dispersive properties, or the frequency responses of all modes present in the structure must be known to predict wave interaction. Currently, there is a lack of methods to predict the response spectrum of guided wave modes, especially in cases when multiple modes are being excited simultaneously. Such methods are of vital importance for further understanding wave propagation within the structures as well as wave-damage interaction. In this study, a novel method to predict the response spectrum of guided wave modes was proposed based on Fourier analysis of the particle velocity distribution on the excitation area. The method proposed in this study estimates an excitability function based on the spatial dimensions of the transducer, type of vibration, and dispersive properties of the medium. As a result, the response amplitude as a function of frequency for each guided wave mode present in the structure can be separately obtained. The method was validated with numerical simulations on the aluminum and glass fiber composite samples. The key findings showed that it can be applied to estimate the response spectrum of a guided wave mode on any type of material (either isotropic structures, or multi layered anisotropic composites) and under any type of excitation if the phase velocity dispersion curve and the particle velocity distribution of the wave source was known initially. Thus, the proposed method may be a beneficial tool to explain

  7. Spectrum

    DEFF Research Database (Denmark)

    Høgfeldt Hansen, Leif

    2016-01-01

    The publication functions as a proces description of the development and construction of an urban furniture SPECTRUM in the city of Gwangju, Republic of Korea. It is used as the cataloque for the exhibition of Spectrum.......The publication functions as a proces description of the development and construction of an urban furniture SPECTRUM in the city of Gwangju, Republic of Korea. It is used as the cataloque for the exhibition of Spectrum....

  8. Acoustic emission source location in plates using wavelet analysis and cross time frequency spectrum.

    Science.gov (United States)

    Mostafapour, A; Davoodi, S; Ghareaghaji, M

    2014-12-01

    In this study, the theories of wavelet transform and cross-time frequency spectrum (CTFS) are used to locate AE source with frequency-varying wave velocity in plate-type structures. A rectangular array of four sensors is installed on the plate. When an impact is generated by an artificial AE source such as Hsu-Nielsen method of pencil lead breaking (PLB) at any position of the plate, the AE signals will be detected by four sensors at different times. By wavelet packet decomposition, a packet of signals with frequency range of 0.125-0.25MHz is selected. The CTFS is calculated by the short-time Fourier transform of the cross-correlation between considered packets captured by AE sensors. The time delay is calculated when the CTFS reaches the maximum value and the corresponding frequency is extracted per this maximum value. The resulting frequency is used to calculate the group velocity of wave velocity in combination with dispersive curve. The resulted locating error shows the high precision of proposed algorithm. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Automatic DGD and GVD compensation at 640 Gb/s based on scalar radio-frequency spectrum measurement

    DEFF Research Database (Denmark)

    Paquot, Yvan; Schröder, Jochen; Palushani, Evarist

    2013-01-01

    of separate GVD and DGD compensators using an impairment monitor based on an integrated all-optical radio-frequency (RF) spectrum analyzer. We show that low-bandwidth measurement of only a single tone in the RF spectrum is sufficient for automatic compensation for multiple degrees of freedom using...

  10. Waves on fluid-loaded shells and their resonance frequency spectrum

    DEFF Research Database (Denmark)

    Bao, X.L.; Uberall, H.; Raju, P.K.

    2005-01-01

    , or axially propagating waves both in the shell material, and in the fluid loading. Previous results by Bao et al. (J. Acoust. Soc. Am. 105 (1999) 2704) were obtained for the circumferential-wave dispersion curves on doubly loaded aluminum shells; the present study extends this to fluid-filled shells in air......Technical requirements for elastic (metal) cylindrical shells include the knowledge of their natural frequency spectrum. These shells may be empty and fluid-immersed, or fluid-filled in an ambient medium of air, or doubly fluid-loaded inside and out. They may support circumferential waves....... For practical applications, steel shells are most important and we have here obtained corresponding results for these. To find the natural frequencies of cylindrical shells, one may invoke the principle of phase matching where resonating standing waves are formed around the circumference, or in the axial...

  11. Power allocation and achievable data rate in spectrum-sharing channels under adaptive primary service outage constraints

    KAUST Repository

    Yang, Yuli; Aï ssa, Sonia

    2012-01-01

    used, provides an interference-tolerable zone. Based on this gap, a secondary user (SU) has an increased opportunity to access the licensed spectrum and to determine the transmit power it should use to keep the PU's quality-of-service (QoS) unaffected

  12. Study of clay behaviour around a heat source by frequency spectrum analysis of seismic waves

    International Nuclear Information System (INIS)

    Sloovere, P. de.

    1993-01-01

    Wave propagated into soft rock is not completely described by purely linear elastic theory. Through spectrum analysis of wave, one can see that several frequencies are selected by the ground. ME2i uses this method to check grouting, piles a.s.o. The Mol experiment (on Radioactive Waste Disposal) aims to prove that little changes into heated clay can be detected by 'frequential seismic'. A cross-hole investigation system has been installed and tests have been performed for two years with a shear-hammer named MARGOT built to work inside horizontal boreholes: - Before heating the tests show the same results every time: . main frequency at 330 hertz; . maximal frequency at 520 hertz; - During heating: . the rays at 330 and 520 hertz disappear; . The frequencies in the range 100 - 300 hertz are prevailing; - After heating spectra have again their original shape. These results show that the effect is clear around an heated zone. The next steps should be: - Interpretation with computer's codes treating of wave propagation into a viscoelastic body; - Experimentations: . at the opening of a new gallery; . on big samples; . on granites and salt. 9 refs., 4 appendices

  13. High-frequency acoustic spectrum analyzer based on polymer integrated optics

    Science.gov (United States)

    Yacoubian, Araz

    This dissertation presents an acoustic spectrum analyzer based on nonlinear polymer-integrated optics. The device is used in a scanning heterodyne geometry by zero biasing a Michelson interferometer. It is capable of detecting vibrations from DC to the GHz range. Initial low frequency experiments show that the device is an effective tool for analyzing an acoustic spectrum even in noisy environments. Three generations of integrated sensors are presented, starting with a very lossy (86 dB total insertion loss) initial device that detects vibrations as low as λ/10, and second and third generation improvements with a final device of 44 dB total insertion loss. The sensor was further tested for detecting a pulsed laser-excited vibration and resonances due to the structure of the sample. The data are compared to the acoustic spectrum measured using a low loss passive fiber interferometer detection scheme which utilizes a high speed detector. The peaks present in the passive detection scheme are clearly visible with our sensor data, which have a lower noise floor. Hybrid integration of GHz electronics is also investigated in this dissertation. A voltage controlled oscillator (VCO) is integrated on a polymer device using a new approach. The VCO is shown to operate as specified by the manufacturer, and the RF signal is efficiently launched onto the micro-strip line used for EO modulation. In the future this technology can be used in conjunction with the presented sensor to produce a fully integrated device containing high frequency drive electronics controlled by low DC voltage. Issues related to device fabrication, loss analysis, RF power delivery to drive circuitry, efficient poling of large area samples, and optimizing poling conditions are also discussed throughout the text.

  14. Optimal Power Allocation for Downstream xDSL With Per-Modem Total Power Constraints: Broadcast Channel Optimal Spectrum Balancing (BC-OSB)

    Science.gov (United States)

    Le Nir, Vincent; Moonen, Marc; Verlinden, Jan; Guenach, Mamoun

    2009-02-01

    Recently, the duality between Multiple Input Multiple Output (MIMO) Multiple Access Channels (MAC) and MIMO Broadcast Channels (BC) has been established under a total power constraint. The same set of rates for MAC can be achieved in BC exploiting the MAC-BC duality formulas while preserving the total power constraint. In this paper, we describe the BC optimal power allo- cation applying this duality in a downstream x-Digital Subscriber Lines (xDSL) context under a total power constraint for all modems over all tones. Then, a new algorithm called BC-Optimal Spectrum Balancing (BC-OSB) is devised for a more realistic power allocation under per-modem total power constraints. The capacity region of the primal BC problem under per-modem total power constraints is found by the dual optimization problem for the BC under per-modem total power constraints which can be rewritten as a dual optimization problem in the MAC by means of a precoder matrix based on the Lagrange multipliers. We show that the duality gap between the two problems is zero. The multi-user power allocation problem has been solved for interference channels and MAC using the OSB algorithm. In this paper we solve the problem of multi-user power allocation for the BC case using the OSB algorithm as well and we derive a computational efficient algorithm that will be referred to as BC-OSB. Simulation results are provided for two VDSL2 scenarios: the first one with Differential-Mode (DM) transmission only and the second one with both DM and Phantom- Mode (PM) transmissions.

  15. Equitable access to spectrum in further development of the Geneva 2006 frequency plan

    Science.gov (United States)

    Philipp, J.

    2011-12-01

    Since the frequency plan of the Regional Radiocommunication Conference Geneva 2006 has come into force, many attempts have been made towards its enhancement. The preliminary results, however, seem not to be compliant with elementary principles of distribution justice. Therefore, the planning principles which lead to the observed imbalance will be scrutinized. Furthermore it will be shown that the utilization of spectrum can be advanced in a balanced way when the same (necessary) condition for "equitable access", which has been used by a group of middle European countries for the construction of the original frequency plan, is applied to plan refinements as well. The necessary condition mentioned consists simply in the parity of the number of coverages (constituted of disjoint allotments) configured in the plan for each country. In order to be able to plan enhancements, the concept of coverage number has to be generalized to the case of incomplete coverages of potentially overlapping allotments. The computation of coverage numbers is straightforward and renders the concept of coverage number parity a useful tool to be applied as a necessary condition in testing a frequency plan variant for equitable access.

  16. 78 FR 9602 - Amendment of the Commission's Rules To Allocate Spectrum and Adopt Service Rules and Procedures...

    Science.gov (United States)

    2013-02-11

    ... application of the FSS in the conventional bands. In the extended band frequencies, VMES may be authorized to... milliseconds of receiving a command from the system's network control and monitoring center. A VMES system... loss of synchronization or within 5 seconds upon loss of reception of the satellite downlink signal...

  17. Allowance for change in the solvent frequency spectrum in the theory of nonadiabatic transitions

    International Nuclear Information System (INIS)

    Ponomarev, O.A.; Khabibullin, R.M.

    1989-01-01

    An explicit expression is obtained for the correlation function of a vibrational subsystem that takes into account memory of the state of the electron subsystem. The correlation function is represented in terms of the retarded Green's functions of the vibrational subsystem for different electron states. The singular equation for the correlation function are solved by reducing them to a canonical system and to the Riemann problem of the jump of a vector function with subsequent nonlinear factorization. This made it possible to solve exactly the problem for an arbitrary initial correlation function and calculate the effect that a change in the frequency spectrum of the solvent has on the process rate constant in the case of a nonradiative transition

  18. Influence of optical feedback on laser frequency spectrum and threshold conditions

    DEFF Research Database (Denmark)

    Osmundsen, Jens Henrik; Gade, Niels

    1983-01-01

    The steady state behavior of the external cavity operated laser has been analyzed, taking into account multiple reflections. The effect of optical feedback is included in the phase- and gain-conditions by a factor which is shown to have a simple geometrical representation. From this representation...... it is easily seen how the laser frequency spectrum and the threshold gain depend on external parameters such as distance to the reflection point and the amount of optical feedback. Furthermore, by inserting a variable attenuator in the external cavity and measuring the threshold current versus transmittance we...... have simultaneously determined the photon lifetime and the absolute amount of optical feedback. For the laser considered we found the photon lifetimetau_{p} = 1.55ps....

  19. Tunable ultranarrow spectrum selective absorption in a graphene monolayer at terahertz frequency

    Science.gov (United States)

    Wu, Jun

    2016-06-01

    Complete absorption in a graphene monolayer at terahertz frequency through the critical coupling effect is investigated. It is achieved by sandwiching the graphene monolayer between a dielectric grating and a Bragg grating. The designed graphene absorber exhibits near-unity absorption at resonance but with an ultranarrow spectrum and antenna-like response, which is attributed to the combined effects of guided mode resonance with dielectric grating and the photonic band gap with Bragg grating. In addition to numerical simulation, the electric field distributions are also illustrated to provide a physical understanding of the perfect absorption effect. Furthermore, the absorption performance can be tuned by only changing the Fermi level of graphene, which is beneficial for real application. It is believed that this study may be useful for designing next-generation graphene-based optoelectronic devices.

  20. Interference Excision in Spread Spectrum Communications Using Adaptive Positive Time-Frequency Analysis

    Directory of Open Access Journals (Sweden)

    Krishnan Sridhar

    2007-01-01

    Full Text Available This paper introduces a novel algorithm to excise single and multicomponent chirp-like interferences in direct sequence spread spectrum (DSSS communications. The excision algorithm consists of two stages: adaptive signal decomposition stage and directional element detection stage based on the Hough-Radon transform (HRT. Initially, the received spread spectrum signal is decomposed into its time-frequency (TF functions using an adaptive signal decomposition algorithm, and the resulting TF functions are mapped onto the TF plane. We then use a line detection algorithm based on the HRT that operates on the image of the TF plane and detects energy varying directional elements that satisfy a parametric constraint. Interference is modeled by reconstructing the corresponding TF functions detected by the HRT, and subtracted from the received signal. The proposed technique has two main advantages: (i it localizes the interferences on the TF plane with no cross-terms, thus facilitating simple filtering techniques based on thresholding of the TF functions, and is an efficient way to excise the interference; (ii it can be used for the detection of any directional interferences that can be parameterized. Simulation results with synthetic models have shown successful performance with linear and quadratic chirp interferences for single and multicomponent interference cases. The proposed method excises the interference even under very low SNR conditions of  dB, and the technique could be easily extended to any interferences that could be represented by a parametric equation in the TF plane.

  1. Energy-efficient orthogonal frequency division multiplexing-based passive optical network based on adaptive sleep-mode control and dynamic bandwidth allocation

    Science.gov (United States)

    Zhang, Chongfu; Xiao, Nengwu; Chen, Chen; Yuan, Weicheng; Qiu, Kun

    2016-02-01

    We propose an energy-efficient orthogonal frequency division multiplexing-based passive optical network (OFDM-PON) using adaptive sleep-mode control and dynamic bandwidth allocation. In this scheme, a bidirectional-centralized algorithm named the receiver and transmitter accurate sleep control and dynamic bandwidth allocation (RTASC-DBA), which has an overall bandwidth scheduling policy, is employed to enhance the energy efficiency of the OFDM-PON. The RTASC-DBA algorithm is used in an optical line terminal (OLT) to control the sleep mode of an optical network unit (ONU) sleep and guarantee the quality of service of different services of the OFDM-PON. The obtained results show that, by using the proposed scheme, the average power consumption of the ONU is reduced by ˜40% when the normalized ONU load is less than 80%, compared with the average power consumption without using the proposed scheme.

  2. Time resolved high frequency spectrum of Br2 molecules using pulsed photoacoustic technique.

    Science.gov (United States)

    Yehya, Fahem; Chaudhary, A K

    2013-11-01

    The paper reports the time resolved spectral distribution of higher order acoustic modes generated in Br2 molecules using pulsed Photoacoustic (PA) technique. New time resolved vibrational spectrum of Br2 molecules are recorded using a single 532nm, pulses of 7ns duration at 10Hz repetition rate obtained from Q-switched Nd:YAG laser. Frank-Condon principle based assignments confirms the presence of 12 numbers of (ν″-ν') vibrational transitions covered by a single 532+2nm pulse profile. Inclusions of higher order zeroth modes in Bassel's function expansion series shows the probability of overlapping of different types of acoustic modes in the designed PA cells. These modes appear in the form of clusters which occupies higher frequency range. The study of decay behavior of PA signal with respect to time confirms the photolysis of Br2 at 532nm wavelength. In addition, the shifting and clustering effect of cavity eigen modes in Br2 molecules have been studied between 1 and 10ms time scale. The estimated Q-factor of PA cell (l=16cm, R=1.4cm) is 145±4 at 27kHz frequency. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Frequency of CNKSR2 mutation in the X-linked epilepsy-aphasia spectrum.

    Science.gov (United States)

    Damiano, John A; Burgess, Rosemary; Kivity, Sara; Lerman-Sagie, Tally; Afawi, Zaid; Scheffer, Ingrid E; Berkovic, Samuel F; Hildebrand, Michael S

    2017-03-01

    Synaptic proteins are critical to neuronal function in the brain, and their deficiency can lead to seizures and cognitive impairments. CNKSR2 (connector enhancer of KSR2) is a synaptic protein involved in Ras signaling-mediated neuronal proliferation, migration and differentiation. Mutations in the X-linked gene CNKSR2 have been described in patients with seizures and neurodevelopmental deficits, especially those affecting language. In this study, we sequenced 112 patients with phenotypes within the epilepsy-aphasia spectrum (EAS) to determine the frequency of CNKSR2 mutation within this complex set of disorders. We detected a novel nonsense mutation (c.2314 C>T; p.Arg712*) in one Ashkenazi Jewish family, the male proband of which had a severe epileptic encephalopathy with continuous spike-waves in sleep (ECSWS). His affected brother also had ECSWS with better outcome, whereas the sister had childhood epilepsy with centrotemporal spikes. This mutation segregated in the three affected siblings in an X-linked manner, inherited from their mother who had febrile seizures. Although the frequency of point mutation is low, CNKSR2 sequencing should be considered in families with suspected X-linked EAS because of the specific genetic counseling implications. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

  4. Estimating parameters of speciation models based on refined summaries of the joint site-frequency spectrum.

    Directory of Open Access Journals (Sweden)

    Aurélien Tellier

    Full Text Available Understanding the processes and conditions under which populations diverge to give rise to distinct species is a central question in evolutionary biology. Since recently diverged populations have high levels of shared polymorphisms, it is challenging to distinguish between recent divergence with no (or very low inter-population gene flow and older splitting events with subsequent gene flow. Recently published methods to infer speciation parameters under the isolation-migration framework are based on summarizing polymorphism data at multiple loci in two species using the joint site-frequency spectrum (JSFS. We have developed two improvements of these methods based on a more extensive use of the JSFS classes of polymorphisms for species with high intra-locus recombination rates. First, using a likelihood based method, we demonstrate that taking into account low-frequency polymorphisms shared between species significantly improves the joint estimation of the divergence time and gene flow between species. Second, we introduce a local linear regression algorithm that considerably reduces the computational time and allows for the estimation of unequal rates of gene flow between species. We also investigate which summary statistics from the JSFS allow the greatest estimation accuracy for divergence time and migration rates for low (around 10 and high (around 100 numbers of loci. Focusing on cases with low numbers of loci and high intra-locus recombination rates we show that our methods for the estimation of divergence time and migration rates are more precise than existing approaches.

  5. Frequency and spectrum of Wolcott–Rallison syndrome in Saudi Arabia: a systematic review

    Directory of Open Access Journals (Sweden)

    Abdelhadi M. Habeb

    2013-06-01

    Full Text Available Background: Wolcott–Rallison syndrome (WRS is caused by recessive EIF2AK3 gene mutations and characterized by permanent neonatal diabetes (PNDM, skeletal dysplasia, and recurrent hepatitis. The frequency of this rare syndrome is largely unknown. Objectives: To define the frequency and spectrum of WRS in the Kingdom of Saudi Arabia (KSA based on published data. Methods: The Medline database was searched for published articles on WRS. The number of reported cases from KSA was compared to the total number of WRS cases reported worldwide. The genotype and phenotype of WRS patients from KSA were reviewed. Results: Ten articles describing 23 WRS patients from 12 Saudi families from 1995 to 2012 were identified. This figure accounts for 27.7% (23/83 of the patients and 22.2% (12/54 of the families with WRS reported worldwide until January 2013. All Saudi patients with WRS presented with PNDM, and they represent 59% of all PNDM cases from WRS. At reporting, 73% of patients experienced recurrent hepatitis, 56.5% had skeletal abnormalities, and 39.1% of them were dead. There was a variation in the phenotype even between affected siblings. Genetic diagnosis was confirmed in all 12 families with no correlation between the genotype and phenotype. Eight of the nine EIF2AK3 mutations were only reported in these families, and one was shared with a patient from Qatar, a neighboring Arab state. Conclusions: No study on the frequency of WRS has been published. However, the available data indicate that KSA has the largest collection of patients with WRS worldwide, and nine of the identifiable EIF2AK3 mutations appear to be confined to Arabs. Establishing a national or international registry for WRS would provide more reliable data on this rare condition.

  6. Power allocation and achievable data rate in spectrum-sharing channels under adaptive primary service outage constraints

    KAUST Repository

    Yang, Yuli

    2012-09-01

    In this paper, we focus on a cognitive radio network where adaptive modulation is adopted in primary links. The gap between the primary user (PU)\\'s received signal-to-noise ratio (SNR) and the lower SNR boundary of the modulation mode that is being used, provides an interference-tolerable zone. Based on this gap, a secondary user (SU) has an increased opportunity to access the licensed spectrum and to determine the transmit power it should use to keep the PU\\'s quality-of-service (QoS) unaffected. However, since the SU cannot obtain perfect information on the PU\\'s received SNR, it has to choose an SNR point between the lower and upper boundaries of the PU\\'s current modulation mode as if this point were the real SNR received by the PU. Considering this issue, in order to quantify the effect of the SU\\'s transmissions on the PU\\'s QoS, we define the PU\\'s service outage probability and obtain its closed-form expressions by taking into account whether the peak transmit power constraint is imposed on the secondary\\'s transmission or not. Subsequently, we derive the SU\\'s achievable data rate in closed form for counterpart scenarios. Numerical results provided here quantify the relation between the PU\\'s service outage probability and the SU\\'s achievable data rate, which further demonstrate that the higher the peak transmit power a secondary transmitter can support, the better performance the cognitive radio network can achieve. © 2012 IEEE.

  7. Interference Excision in Spread Spectrum Communications Using Adaptive Positive Time-Frequency Analysis

    Directory of Open Access Journals (Sweden)

    Sridhar Krishnan

    2007-07-01

    Full Text Available This paper introduces a novel algorithm to excise single and multicomponent chirp-like interferences in direct sequence spread spectrum (DSSS communications. The excision algorithm consists of two stages: adaptive signal decomposition stage and directional element detection stage based on the Hough-Radon transform (HRT. Initially, the received spread spectrum signal is decomposed into its time-frequency (TF functions using an adaptive signal decomposition algorithm, and the resulting TF functions are mapped onto the TF plane. We then use a line detection algorithm based on the HRT that operates on the image of the TF plane and detects energy varying directional elements that satisfy a parametric constraint. Interference is modeled by reconstructing the corresponding TF functions detected by the HRT, and subtracted from the received signal. The proposed technique has two main advantages: (i it localizes the interferences on the TF plane with no cross-terms, thus facilitating simple filtering techniques based on thresholding of the TF functions, and is an efficient way to excise the interference; (ii it can be used for the detection of any directional interferences that can be parameterized. Simulation results with synthetic models have shown successful performance with linear and quadratic chirp interferences for single and multicomponent interference cases. The proposed method excises the interference even under very low SNR conditions of −10 dB, and the technique could be easily extended to any interferences that could be represented by a parametric equation in the TF plane.

  8. Engineering the Frequency Spectrum of Bright Squeezed Vacuum via Group Velocity Dispersion in an SU(1,1) Interferometer

    OpenAIRE

    Lemieux, Samuel; Manceau, Mathieu; Sharapova, Polina R.; Tikhonova, Olga V.; Boyd, Robert W.; Leuchs, Gerd; Chekhova, Maria V.

    2016-01-01

    Bright squeezed vacuum, a promising tool for quantum information, can be generated by high-gain parametric down-conversion. However, its frequency and angular spectra are typically quite broad, which is undesirable for applications requiring single-mode radiation. We tailor the frequency spectrum of high-gain parametric down-conversion using an SU(1,1) interferometer consisting of two nonlinear crystals with a dispersive medium separating them. The dispersive medium allows us to select a narr...

  9. High-Resolution Time-Frequency Spectrum-Based Lung Function Test from a Smartphone Microphone

    Directory of Open Access Journals (Sweden)

    Tharoeun Thap

    2016-08-01

    Full Text Available In this paper, a smartphone-based lung function test, developed to estimate lung function parameters using a high-resolution time-frequency spectrum from a smartphone built-in microphone is presented. A method of estimation of the forced expiratory volume in 1 s divided by forced vital capacity (FEV1/FVC based on the variable frequency complex demodulation method (VFCDM is first proposed. We evaluated our proposed method on 26 subjects, including 13 healthy subjects and 13 chronic obstructive pulmonary disease (COPD patients, by comparing with the parameters clinically obtained from pulmonary function tests (PFTs. For the healthy subjects, we found that an absolute error (AE and a root mean squared error (RMSE of the FEV1/FVC ratio were 4.49% ± 3.38% and 5.54%, respectively. For the COPD patients, we found that AE and RMSE from COPD patients were 10.30% ± 10.59% and 14.48%, respectively. For both groups, we compared the results using the continuous wavelet transform (CWT and short-time Fourier transform (STFT, and found that VFCDM was superior to CWT and STFT. Further, to estimate other parameters, including forced vital capacity (FVC, forced expiratory volume in 1 s (FEV1, and peak expiratory flow (PEF, regression analysis was conducted to establish a linear transformation. However, the parameters FVC, FEV1, and PEF had correlation factor r values of 0.323, 0.275, and −0.257, respectively, while FEV1/FVC had an r value of 0.814. The results obtained suggest that only the FEV1/FVC ratio can be accurately estimated from a smartphone built-in microphone. The other parameters, including FVC, FEV1, and PEF, were subjective and dependent on the subject’s familiarization with the test and performance of forced exhalation toward the microphone.

  10. Emerging Telecommunications Technologies (Part 2). Hearing before the Subcommittee on Telecommunications and Finance of the Committee on Energy and Commerce on H.R. 1407, a Bill To Establish Procedures To Improve the Allocation and Assignment to the Electromagnetic Spectrum. House of Representatives, One Hundred Second Congress, First Session.

    Science.gov (United States)

    Congress of the U.S., Washington, DC. House Committee on Energy and Commerce.

    A discussion of H.R. 1407, a bill to establish procedures to improve the allocation and assignment to the electromagnetic spectrum centered on the current policy of allocating portions of the spectrum through lotteries and auction. This report includes a copy of the bill, the text of testimony presented and materials submitted for the record, and…

  11. The doubly conditioned frequency spectrum does not distinguish between ancient population structure and hybridization

    KAUST Repository

    Eriksson, Anders

    2014-03-13

    Distinguishing between hybridization and population structure in the ancestral species is a key challenge in our understanding of how permeable species boundaries are to gene flow. The doubly conditioned frequency spectrum (dcfs) has been argued to be a powerful metric to discriminate between these two explanations, and it was used to argue for hybridization between Neandertal and anatomically modern humans. The shape of the observed dcfs for these two species cannot be reproduced by a model that represents ancient population structure in Africa with two populations, while adding hybridization produces realistic shapes. In this letter, we show that this result is a consequence of the spatial coarseness of the demographic model and that a spatially structured stepping stone model can generate realistic dcfs without hybridization. This result highlights how inferences on hybridization between recently diverged species can be strongly affected by the choice of how population structure is represented in the underlying demographic model. We also conclude that the dcfs has limited power in distinguishing between the signals left by hybridization and ancient structure. 2014 The Author.

  12. MATERNAL ALCOHOL CONSUMPTION PRODUCING FETAL ALCOHOL SPECTRUM DISORDERS (FASD): QUANTITY, FREQUENCY, AND TIMING OF DRINKING

    Science.gov (United States)

    May, Philip A.; Blankenship, Jason; Marais, Anna-Susan; Gossage, J. Phillip; Kalberg, Wendy O.; Joubert, Belinda; Cloete, Marise; Barnard, Ronel; De Vries, Marlene; Hasken, Julie; Robinson, Luther K.; Adnams, Colleen M.; Buckley, David; Manning, Melanie; Parry, Charles; Hoyme, H. Eugene; Tabachnick, Barbara; Seedat, Soraya

    2013-01-01

    Background Concise, accurate measures of maternal prenatal alcohol use are needed to better understand fetal alcohol spectrum disorders (FASD). Methods Measures of drinking by mothers of children with specific FASD diagnoses and mothers of randomly-selected controls are compared and also correlated with physical and cognitive/behavioral outcomes. Results Measures of maternal alcohol use can differentiate maternal drinking associated with FASD from that of controls and some from mothers of alcohol-exposed normals. Six variables that combine quantity and frequency concepts distinguish mothers of FASD children from normal controls. Alcohol use variables, when applied to each trimester and three months prior to pregnancy, provide insight on critical timing of exposure as well. Measures of drinking, especially bingeing, correlate significantly with increased child dysmorphology and negative cognitive/behavioral outcomes in children, especially low non-verbal IQ, poor attention, and behavioral problems. Logistic regression links (palcohol consumption both within and between diagnostic groupings of mothers bearing children diagnosed within the FASD continuum. Drinking measures are empirically identified and correlated with specific child outcomes. Alcohol use, especially heavy use, should be avoided throughout pregnancy. PMID:23932841

  13. Decomposing the Site Frequency Spectrum: The Impact of Tree Topology on Neutrality Tests.

    Science.gov (United States)

    Ferretti, Luca; Ledda, Alice; Wiehe, Thomas; Achaz, Guillaume; Ramos-Onsins, Sebastian E

    2017-09-01

    We investigate the dependence of the site frequency spectrum on the topological structure of genealogical trees. We show that basic population genetic statistics, for instance, estimators of θ or neutrality tests such as Tajima's D , can be decomposed into components of waiting times between coalescent events and of tree topology. Our results clarify the relative impact of the two components on these statistics. We provide a rigorous interpretation of positive or negative values of an important class of neutrality tests in terms of the underlying tree shape. In particular, we show that values of Tajima's D and Fay and Wu's H depend in a direct way on a peculiar measure of tree balance, which is mostly determined by the root balance of the tree. We present a new test for selection in the same class as Fay and Wu's H and discuss its interpretation and power. Finally, we determine the trees corresponding to extreme expected values of these neutrality tests and present formulas for these extreme values as a function of sample size and number of segregating sites. Copyright © 2017 by the Genetics Society of America.

  14. Accuracy of Demographic Inferences from the Site Frequency Spectrum: The Case of the Yoruba Population.

    Science.gov (United States)

    Lapierre, Marguerite; Lambert, Amaury; Achaz, Guillaume

    2017-05-01

    Some methods for demographic inference based on the observed genetic diversity of current populations rely on the use of summary statistics such as the Site Frequency Spectrum (SFS). Demographic models can be either model-constrained with numerous parameters, such as growth rates, timing of demographic events, and migration rates, or model-flexible, with an unbounded collection of piecewise constant sizes. It is still debated whether demographic histories can be accurately inferred based on the SFS. Here, we illustrate this theoretical issue on an example of demographic inference for an African population. The SFS of the Yoruba population (data from the 1000 Genomes Project) is fit to a simple model of population growth described with a single parameter ( e.g. , founding time). We infer a time to the most recent common ancestor of 1.7 million years (MY) for this population. However, we show that the Yoruba SFS is not informative enough to discriminate between several different models of growth. We also show that for such simple demographies, the fit of one-parameter models outperforms the stairway plot, a recently developed model-flexible method. The use of this method on simulated data suggests that it is biased by the noise intrinsically present in the data. Copyright © 2017 by the Genetics Society of America.

  15. The doubly conditioned frequency spectrum does not distinguish between ancient population structure and hybridization

    KAUST Repository

    Eriksson, Anders; Manica, Andrea

    2014-01-01

    Distinguishing between hybridization and population structure in the ancestral species is a key challenge in our understanding of how permeable species boundaries are to gene flow. The doubly conditioned frequency spectrum (dcfs) has been argued to be a powerful metric to discriminate between these two explanations, and it was used to argue for hybridization between Neandertal and anatomically modern humans. The shape of the observed dcfs for these two species cannot be reproduced by a model that represents ancient population structure in Africa with two populations, while adding hybridization produces realistic shapes. In this letter, we show that this result is a consequence of the spatial coarseness of the demographic model and that a spatially structured stepping stone model can generate realistic dcfs without hybridization. This result highlights how inferences on hybridization between recently diverged species can be strongly affected by the choice of how population structure is represented in the underlying demographic model. We also conclude that the dcfs has limited power in distinguishing between the signals left by hybridization and ancient structure. 2014 The Author.

  16. Autonomic nervous system activity in purebred Arabian horses evaluated according to the low frequency and high frequency spectrum versus racing performance

    Directory of Open Access Journals (Sweden)

    Iwona Janczarek

    2016-01-01

    Full Text Available Emotional excitability influences horses’ performance in sports and races. The aim of the study was to analyse whether the balance of the autonomic system which can occur when sympathetic system activity is at various levels might impact the horses’ racing performance. The study was carried out on 67 purebred Arabian horses trained for racing. The following indices were analysed: low frequency (LF, high frequency (HF, and the ratio of spectrum power at low frequencies to high frequencies (LF/HF. The autonomic nervous system activity was measured × 3 during the training season, at three-month intervals. Each examination included a 30-min measurement at rest and after a training session. The racing performance indices in these horses were also analysed. Better racing results were found in horses with enhanced LF/HF. The worst racing results were determined in horses with low LF.

  17. Chunk-Based Energy Efficient Resource Allocation in OFDMA Systems

    Directory of Open Access Journals (Sweden)

    Yong Li

    2013-01-01

    Full Text Available Energy efficiency (EE capacity analysis of the chunk-based resource allocation is presented by considering the minimum spectrum efficiency (SE constraint in downlink multiuser orthogonal frequency division multiplexing (OFDM systems. Considering the minimum SE requirement, an optimization problem to maximize EE with limited transmit power is formulated over frequency selective channels. Based on this model, a low-complexity energy efficient resource allocation is proposed. The effects of system parameters, such as the average channel gain-to-noise ratio (CNR and the number of subcarriers per chunk, are evaluated. Numerical results demonstrate the effectiveness of the proposed scheme for balancing the EE and SE.

  18. Maternal alcohol consumption producing fetal alcohol spectrum disorders (FASD): quantity, frequency, and timing of drinking.

    Science.gov (United States)

    May, Philip A; Blankenship, Jason; Marais, Anna-Susan; Gossage, J Phillip; Kalberg, Wendy O; Joubert, Belinda; Cloete, Marise; Barnard, Ronel; De Vries, Marlene; Hasken, Julie; Robinson, Luther K; Adnams, Colleen M; Buckley, David; Manning, Melanie; Parry, Charles D H; Hoyme, H Eugene; Tabachnick, Barbara; Seedat, Soraya

    2013-12-01

    Concise, accurate measures of maternal prenatal alcohol use are needed to better understand fetal alcohol spectrum disorders (FASD). Measures of drinking by mothers of children with specific FASD diagnoses and mothers of randomly-selected controls are compared and also correlated with physical and cognitive/behavioral outcomes. Measures of maternal alcohol use can differentiate maternal drinking associated with FASD from that of controls and some from mothers of alcohol-exposed normals. Six variables that combine quantity and frequency concepts distinguish mothers of FASD children from normal controls. Alcohol use variables, when applied to each trimester and three months prior to pregnancy, provide insight on critical timing of exposure as well. Measures of drinking, especially bingeing, correlate significantly with increased child dysmorphology and negative cognitive/behavioral outcomes in children, especially low non-verbal IQ, poor attention, and behavioral problems. Logistic regression links (p<.001) first trimester drinking (vs. no drinking) with FASD, elevating FASD likelihood 12 times; first and second trimester drinking increases FASD outcomes 61 times; and drinking in all trimesters 65 times. Conversely, a similar regression (p=.008) indicates that drinking only in the first trimester makes the birth of a child with an FASD 5 times less likely than drinking in all trimesters. There is significant variation in alcohol consumption both within and between diagnostic groupings of mothers bearing children diagnosed within the FASD continuum. Drinking measures are empirically identified and correlated with specific child outcomes. Alcohol use, especially heavy use, should be avoided throughout pregnancy. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  19. Spectrum and frequency of chlorophyll mutations in urdbean (Vigna mungo L. Hepper) induced by EMS and gamma rays

    International Nuclear Information System (INIS)

    Sharma, A.K.; Singh, V.P.; Sarma, M.K.

    2006-01-01

    In mutation breeding experiment, plants with altered characteristics such as chlorophyll changes, sterility, plant lethality etc. could be the marker of the mutability of a variety. In fact, spectrum and frequency of chlorophyll mutations have been studied in the great detail. The chlorophyll mutation is the clear-cut indication of non-directional nature of mutation and possibility of induction of useful mutations. The spectrum and frequency of chlorophyll mutation was estimated by using gamma rays (100, 200, 300 and 400 Gy doses), EMS (0.2, 0.4, 0.6 and 0.8%) and combination of gamma rays (100, 200, 300 400 Gy) with 0.2 % concentration EMS on two cultivars, namely, Pant Urd-19 and Pant Urd-30 of urdbean ( Vigna mungo L. Hepper). Five different types of chlorophyll mutations viz., albina, xantha, viridis, chlorina and maculata were identified in both the cultivars. Almost all the combination treatments produced maximum frequency and wider spectrum of chlorophyll mutations followed by single treatment of gamma rays or EMS. The frequency of chlorophyll mutation increased with higher doses of mutagens but decreased at highest dose. Proc. Nat. Acad. Sci. India. 76(8), I, 2006. 64-68. (author)

  20. High-resolution vertical velocities and their power spectrum observed with the MAARSY radar - Part 1: frequency spectrum

    Science.gov (United States)

    Li, Qiang; Rapp, Markus; Stober, Gunter; Latteck, Ralph

    2018-04-01

    The Middle Atmosphere Alomar Radar System (MAARSY) installed at the island of Andøya has been run for continuous probing of atmospheric winds in the upper troposphere and lower stratosphere (UTLS) region. In the current study, we present high-resolution wind measurements during the period between 2010 and 2013 with MAARSY. The spectral analysis applying the Lomb-Scargle periodogram method has been carried out to determine the frequency spectra of vertical wind velocity. From a total of 522 days of observations, the statistics of the spectral slope have been derived and show a dependence on the background wind conditions. It is a general feature that the observed spectra of vertical velocity during active periods (with wind velocity > 10 m s-1) are much steeper than during quiet periods (with wind velocity wind conditions considered together the general spectra are obtained and their slopes are compared with the background horizontal winds. The comparisons show that the observed spectra become steeper with increasing wind velocities under quiet conditions, approach a spectral slope of -5/3 at a wind velocity of 10 m s-1 and then roughly maintain this slope (-5/3) for even stronger winds. Our findings show an overall agreement with previous studies; furthermore, they provide a more complete climatology of frequency spectra of vertical wind velocities under different wind conditions.

  1. Influence of two-stream relativistic electron beam parameters on the space-charge wave with broad frequency spectrum formation

    Science.gov (United States)

    Alexander, LYSENKO; Iurii, VOLK

    2018-03-01

    We developed a cubic non-linear theory describing the dynamics of the multiharmonic space-charge wave (SCW), with harmonics frequencies smaller than the two-stream instability critical frequency, with different relativistic electron beam (REB) parameters. The self-consistent differential equation system for multiharmonic SCW harmonic amplitudes was elaborated in a cubic non-linear approximation. This system considers plural three-wave parametric resonant interactions between wave harmonics and the two-stream instability effect. Different REB parameters such as the input angle with respect to focusing magnetic field, the average relativistic factor value, difference of partial relativistic factors, and plasma frequency of partial beams were investigated regarding their influence on the frequency spectrum width and multiharmonic SCW saturation levels. We suggested ways in which the multiharmonic SCW frequency spectrum widths could be increased in order to use them in multiharmonic two-stream superheterodyne free-electron lasers, with the main purpose of forming a powerful multiharmonic electromagnetic wave.

  2. Computing the spectrum of black hole radiation in the presence of high frequency dispersion: an analytical approach

    OpenAIRE

    Corley, Steven

    1997-01-01

    We present a method for computing the spectrum of black hole radiation of a scalar field satisfying a wave equation with high frequency dispersion. The method involves a combination of Laplace transform and WKB techniques for finding approximate solutions to ordinary differential equations. The modified wave equation is obtained by adding a higher order derivative term suppressed by powers of a fundamental momentum scale $k_0$ to the ordinary wave equation. Depending on the sign of this new t...

  3. The effect of pressurizer-water-level on the low frequency component of the pressure spectrum in a PWR

    International Nuclear Information System (INIS)

    Por, G.; Izsak, E.; Valko, J.

    1984-09-01

    The pressure fluctuations were measured in the cooling system of the Paks-1 reactor. A shift of the peak was detected in low frequency component of the pressure fluctuation spectrum which is due to the fluctuations of water level in the pressurizer. Using the model of Katona and Nagy (1983), the eigenfrequencies, the magnitude of the shift and the sensitivity to the pressurizer water level were reproduced in good accordance with the experimental data. (D.Gy.)

  4. Effects of aromaticity in cations and their functional groups on the temperature dependence of low-frequency spectrum

    Science.gov (United States)

    Kakinuma, Shohei; Ramati, Sharon; Wishart, James F.; Shirota, Hideaki

    2018-05-01

    In this study, we investigate the temperature dependence of low-frequency spectra in the frequency range of 0.3-200 cm-1 for ionic liquids (ILs) whose cations possess two systematically different cyclic groups, using femtosecond Raman-induced Kerr effect spectroscopy. The target ILs are bis(trifluoromethylsulfonyl)amide [NTf2]- salts of 1-cyclohexylmethyl-1-methylpyrrolidinium [CHxmMPyrr]+, 1-cyclohexylmethyl-3-methylimidazolium [CHxmMIm]+, N-cyclohexylmethylpyridinium [CHxmPy]+, 1-benzyl-1-methylpyrrolidinium [BzMPyrr]+, 1-benzyl-3-methylimidazolium [BzMIm]+, and N-benzylpyridinium [BzPy]+ cations. The aim of this study is to better understand the effects of aromaticity in the cations' constituent groups on the temperature-dependent low-frequency spectral features of the ILs. The low-frequency spectra of these ILs are temperature dependent, but the temperature-dependent spectrum of [CHxmMPyrr][NTf2] is different from that of other ILs. While [CHxmMPyrr][NTf2] shows spectral changes with temperature in the low-frequency region below 50 cm-1, the other ILs also show spectral changes in the high-frequency region above 80 cm-1 (above 50 cm-1 in the case of [BzMPyrr][NTf2]). We conclude that the spectral change in the low-frequency region is due to both the cation and anion, while the change in the high-frequency region is attributed to the red shift of the aromatic ring librations. On the basis of the plots of the first moment of the spectra vs. temperature, we found that the first moment of the low-frequency spectrum of the IL whose cation does not have an aromatic ring is less temperature dependent than that of the other ILs. However, the intrinsic first moment, the first moment at 0 K, of the low-frequency spectrum is governed by the absence or presence of a charged aromatic group, while a neutral aromatic group does not have much influence on determining the intrinsic first moment.

  5. Alternative Paths to Hearing (A Conjecture. Photonic and Tactile Hearing Systems Displaying the Frequency Spectrum of Sound

    Directory of Open Access Journals (Sweden)

    E. H. Hara

    2006-01-01

    Full Text Available In this article, the hearing process is considered from a system engineering perspective. For those with total hearing loss, a cochlear implant is the only direct remedy. It first acts as a spectrum analyser and then electronically stimulates the neurons in the cochlea with a number of electrodes. Each electrode carries information on the separate frequency bands (i.e., spectrum of the original sound signal. The neurons then relay the signals in a parallel manner to the section of the brain where sound signals are processed. Photonic and tactile hearing systems displaying the spectrum of sound are proposed as alternative paths to the section of the brain that processes sound. In view of the plasticity of the brain, which can rewire itself, the following conjectures are offered. After a certain period of training, a person without the ability to hear should be able to decipher the patterns of photonic or tactile displays of the sound spectrum and learn to ‘hear’. This is very similar to the case of a blind person learning to ‘read’ by recognizing the patterns created by the series of bumps as their fingers scan the Braille writing. The conjectures are yet to be tested. Designs of photonic and tactile systems displaying the sound spectrum are outlined.

  6. Emerging Telecommunications Technologies. Hearings on H.R. 707, A Bill To Establish Procedures To Improve the Allocation and Assignment of the Electromagnetic Spectrum, before the Subcommittee on Telecommunications and Finance of the Committee on Energy and Commerce. House of Representatives, One Hundred Third Congress, First Session (February 4 and April 22, 1993).

    Science.gov (United States)

    Congress of the U.S., Washington, DC. House Subcommittee on Telecommunications and Finance.

    The testimony responds to H.R. 707, a bill to identify 200 megahertz of electromagnetic spectrum for allocation to private and non-federal government users. The witnesses address how the spectrum can be used to deliver new products and services to all Americans; how additional radio spectrum is needed to keep America competitive; how wireless…

  7. Feedback-Based Admission Control for Firm Real-Time Task Allocation with Dynamic Voltage and Frequency Scaling

    Directory of Open Access Journals (Sweden)

    Piotr Dziurzanski

    2018-04-01

    Full Text Available Feedback-based mechanisms can be employed to monitor the performance of Multiprocessor Systems-on-Chips (MPSoCs and steer the task execution even if the exact knowledge of the workload is unknown a priori. In particular, traditional proportional-integral controllers can be used with firm real-time tasks to either admit them to the processing cores or reject in order not to violate the timeliness of the already admitted tasks. During periods with a lower computational power demand, dynamic voltage and frequency scaling (DVFS can be used to reduce the dissipation of energy in the cores while still not violating the tasks’ time constraints. Depending on the workload pattern and weight, platform size and the granularity of DVFS, energy savings can reach even 60% at the cost of a slight performance degradation.

  8. Effects of Weekly Low-Frequency rTMS on Autonomic Measures in Children with Autism Spectrum Disorder

    Directory of Open Access Journals (Sweden)

    Manuel Fernando Casanova

    2014-10-01

    Full Text Available The term autism spectrum disorder (ASD describes a range of conditions characterized by impairments in social interactions, communication, and by restricted and repetitive behaviors. ASD may also present with symptoms suggestive of autonomic nervous system (ANS dysfunction. The objective of this study was to determine the effect of 18 sessions of low frequency repetitive transcranial magnetic stimulation (rTMS on autonomic function in children with ASD by recording electrocardiogram (EKG and electrodermal activity pre-, post- and during each rTMS session. The autonomic measures of interest in this study were R-R cardiointervals in EKG (R-R, time and frequency domain measures of heart rate variability (HRV and skin conductance level (SCL. HRV measures such as R-R intervals, standard deviation of cardiac intervals, pNN50 (percentage of cardiointervals>50 ms different from preceding interval, power of high frequency (HF and low frequency (LF components of HRV spectrum, LF/HF ratio, were then derived from the recorded EKG. We expected that the course of 18 weekly inhibitory low-frequency rTMS applied to the dorsolateral prefrontal cortex (DLPFC would enhance autonomic balance by facilitating frontal inhibition of limbic activity thus resulting in decreased overall heart rate, increased HRV (in a form of increased HF power, decreased LF power (resulting in decreased LF/HF ratio, and decreased SCL. Behavioral evaluations post-18 TMS showed decreased irritability, hyperactivity, stereotype behavior and compulsive behavior ratings while autonomic measures indicated a significant increase in cardiac interval variability and a decrease of tonic SCL. The results suggest that 18 sessions of low frequency rTMS in ASD results in increased cardiac vagal control and reduced sympathetic arousal.

  9. Visibility-based angular power spectrum estimation in low-frequency radio interferometric observations

    NARCIS (Netherlands)

    Choudhuri, Samir; Bharadwaj, Somnath; Ghosh, Abhik; Ali, Sk. Saiyad

    2014-01-01

    We present two estimators to quantify the angular power spectrum of the sky signal directly from the visibilities measured in radio interferometric observations. This is relevant for both the foregrounds and the cosmological 21-cm signal buried therein. The discussion here is restricted to the

  10. Analgesic effect of the electromagnetic resonant frequencies derived from the NMR spectrum of morphine.

    Science.gov (United States)

    Verginadis, Ioannis I; Simos, Yannis V; Velalopoulou, Anastasia P; Vadalouca, Athina N; Kalfakakou, Vicky P; Karkabounas, Spyridon Ch; Evangelou, Angelos M

    2012-12-01

    Exposure to various types of electromagnetic fields (EMFs) affects pain specificity (nociception) and pain inhibition (analgesia). Previous study of ours has shown that exposure to the resonant spectra derived from biologically active substances' NMR may induce to live targets the same effects as the substances themselves. The purpose of this study is to investigate the potential analgesic effect of the resonant EMFs derived from the NMR spectrum of morphine. Twenty five Wistar rats were divided into five groups: control group; intraperitoneal administration of morphine 10 mg/kg body wt; exposure of rats to resonant EMFs of morphine; exposure of rats to randomly selected non resonant EMFs; and intraperitoneal administration of naloxone and simultaneous exposure of rats to the resonant EMFs of morphine. Tail Flick and Hot Plate tests were performed for estimation of the latency time. Results showed that rats exposed to NMR spectrum of morphine induced a significant increase in latency time at time points (p spectrum of morphine. Our results indicate that exposure of rats to the resonant EMFs derived from the NMR spectrum of morphine may exert on animals similar analgesic effects to morphine itself.

  11. NAFASS: Fluctuation spectroscopy and the Prony spectrum for description of multi-frequency signals in complex systems

    Science.gov (United States)

    Nigmatullin, R. R.; Gubaidullin, I. A.

    2018-03-01

    In this paper, we essentially modernize the NAFASS (Non-orthogonal Amplitude Frequency Analysis of the Smoothed Signals) approach suggested earlier. Actually, we solved two important problems: (a) new and effective algorithm was proposed and (b) we proved that the segment of the Prony spectrum could be used as the fitting function for description of the desired frequency spectrum. These two basic elements open an alternative way for creation of the fluctuation spectroscopy when the segment of the Fourier series can fit any random signal with trend but the dispersion spectrum of the Fourier series ω0 · k(ω0 ≡ 2 π / T) ⇒Ωk(k = 0 , 1 , 2 , . . . , K - 1) is replaced by the specific dispersion law Ωk calculated with the help of original algorithm described below. It implies that any finite signal will have a compact amplitude-frequency response (AFR), where the number of the modes is much less in comparison with the number of data points (K economic data and compare 30-years world prices for meat (beef, chicken, lamb and pork) entering as the basic components to every-day food consumption. These data were taken from the official site http://www.indexmundi.com/commodities/. We fitted these random functions with the high accuracy and calculated the desired ;amplitude-frequency; response for these random price fluctuations. The calculated distribution of the amplitudes (Ack, Ask) and frequency spectrum Ωk (k = 0, 1,…, K-1) allows one to compress initial data (K (number of modes) << N (number of data points), N/K ≅ 20-40) and receive an additional information for their comparison with each other. As the second example, we considered the transcendental/irrational numbers description in the frame of the proposed NAFASS approach, as well. This possibility was demonstrated on the quantitative description of the transcendental number π = 3.1415926535897932…, containing initially 6ṡ104 digits. The results obtained for the second type of data can be useful for

  12. Low-frequency logarithmic discretization of the reservoir spectrum for improving the efficiency of hierarchical equations of motion approach.

    Science.gov (United States)

    Ye, LvZhou; Zhang, Hou-Dao; Wang, Yao; Zheng, Xiao; Yan, YiJing

    2017-08-21

    An efficient low-frequency logarithmic discretization (LFLD) scheme for the decomposition of fermionic reservoir spectrum is proposed for the investigation of quantum impurity systems. The scheme combines the Padé spectrum decomposition (PSD) and a logarithmic discretization of the residual part in which the parameters are determined based on an extension of the recently developed minimum-dissipaton ansatz [J. J. Ding et al., J. Chem. Phys. 145, 204110 (2016)]. A hierarchical equations of motion (HEOM) approach is then employed to validate the proposed scheme by examining the static and dynamic system properties in both the Kondo and noninteracting regimes. The LFLD scheme requires a much smaller number of exponential functions than the conventional PSD scheme to reproduce the reservoir correlation function and thus facilitates the efficient implementation of the HEOM approach in extremely low temperature regimes.

  13. Spatial-frequency spectrum of patterns changes the visibility of spatial-phase differences

    Science.gov (United States)

    Lawton, T. B.

    1985-01-01

    It is shown that spatial-frequency components over a 4-octave range affected the visibility of spatial-phase differences. Contrast thresholds were measured for discrimination between two (+45- and -45-deg) spatial phases of a sinusoidal test grating added to a background grating. The background could contain one or several sinusoidal components, all in 0-deg phase. Phase differences between the test and the background were visible at lower contrasts when test and background frequencies were harmonically related than when they were not, when test and background frequencies were within 1 octave than when they were farther apart, when the fundamental frequency of the background was low than when it was high, and for some discriminations more than for others, after practice. The visibility of phase differences was not affected by additional components in the background if the fundamental and difference frequencies of the background remained unchanged. Observers' reports of their strategies gave information about the types of attentive processing that were used to discriminate phase differences. Attentive processing facilitated phase discrimination for multifrequency gratings spanning a much wider range of spatial frequencies than would be possible by using only local preattentive processing. These results were consistent with the visibility of phase differences being processed by some combination of even- and odd-symmetric simple cells tuned to a wide range of different spatial frequencies.

  14. New indices for quantification of the power spectrum of heart rate variability time series without the need of any frequency band definition

    International Nuclear Information System (INIS)

    García-González, M A; Fernández-Chimeno, M; Benítez, A; Ramos-Castro, J; Ferrer, J; Escorihuela, R M; Parrado, E; Capdevila, L; Angulo, R; Rodríguez, F A; Iglesias, X; Bescós, R; Marina, M; Padullés, J M

    2011-01-01

    This paper presents a new family of indices for the frequency domain analysis of heart rate variability time series that do not need any frequency band definition. After proper detrending of the time series, a cumulated power spectrum is obtained and frequencies that contain a certain percentage of the power below them are identified, so median frequency, bandwidth and a measure of the power spectrum asymmetry are proposed to complement or improve the classical spectral indices as the ratio of the powers of LF and HF bands (LF/HF). In normal conditions the median frequency provides similar information as the classical indices, while the bandwidth and asymmetry can be complementary measures of the physiological state of the tested subject. The proposed indices seem to be a good choice for tracking changes in the power spectrum in exercise stress, and they can guide in the determination of frequency band limits in other animal species

  15. Frequency Selective Filtering of the Modulation Spectrum and its Impact on Consonant Identification

    DEFF Research Database (Denmark)

    Christiansen, Thomas Ulrich; Greenberg, Steven

    2005-01-01

    The spectro-temporal coding of Danish consonants was investigated using an information-theoretic approach. Listeners were asked to identify eleven different consonants spoken in a CV[l] syllable context (where C refers to the initial consonant, V refers to one of three vowels, [I, a, u], and [l] ....... In addition, the analysis provides a means to associate specific portions of the modulation spectrum with phonetic feature properties. Such analyses indicate that: (1) Accurate, robust decoding of place-of-articulation information requires broadband cross-spectral integration (2) Place......-of-articulation information is associated most closely with the modulation spectrum above 6 Hz, with the most significant contribution coming from the region above 12 Hz. (3) Place-of-articulation information is crucial for accurate consonant recognition. Hence, consonant decoding requires cross-spectral integration...

  16. TV White Space the first step towards better utilization of frequency spectrum

    CERN Document Server

    Wah Oh, Ser; Tao, Ming-Hung; Peh, Edward

    2017-01-01

    This book covers the full spectrum of TVWS technology including regulations, technology, standardizations, and worldwide deployments. It begins with an introduction to cognitive radio and TVWS. The regulation activities in TVWS throughout North America, Europe, and Asia Pacific are covered in depth. After a discussion of regulations, the authors examine the standardizations developed to specify the enabling technologies of TVWS systems. The following chapter focuses on the key technologies that differentiate TVWS from a conventional wireless communication system.

  17. Orthostatic Tremor: A Spectrum of Fast and Slow Frequencies or Distinct Entities?

    OpenAIRE

    Rigby, Heather B.; Rigby, Matthew H.; Caviness, John N.

    2015-01-01

    Background: Orthostatic tremor (OT) is defined by the presence of a high-frequency (13–18 Hz) tremor of the legs upon standing associated with a feeling of unsteadiness. However, some patients have discharge frequencies of <13 Hz, so-called “slow OT”. The aim of this study was to characterize patients with unsteadiness upon standing found to have <13 Hz tremor discharges on neurophysiologic testing. Methods: A retrospective review was performed on all subjects with a d...

  18. Higher frequency of brain abnormalities in neuromyelitis optica spectrum disorder patients without primary Sjögren's syndrome.

    Science.gov (United States)

    Gu, Li-Na; Zhang, Min; Zhu, Hui; Liu, Jing-Yao

    2016-10-01

    Neuromyelitis optica spectrum disorder often co-exists with primary Sjögren's syndrome. We compared the clinical features of 16 neuromyelitis optica spectrum disorder patients with ( n = 6) or without primary Sjögren's syndrome ( n = 10). All patients underwent extensive clinical, laboratory, and MRI evaluations. There were no statistical differences in demographics or first neurological involvement at onset between neuromyelitis optica spectrum disorder patients with and without primary Sjögren's syndrome. The laboratory findings of cerebrospinal fluid oligoclonal banding, serum C-reactive protein, antinuclear autoantibody, anti-Sjögren's-syndrome-related antigen A antibodies, anti-Sjögren's-syndrome-related antigen B antibodies, and anti-Sm antibodies were significantly higher in patients with primary Sjögren's syndrome than those without. Anti-aquaporin 4 antibodies were detectable in 67% (4/6) of patients with primary Sjögren's syndrome and in 60% (6/10) of patients without primary Sjögren's syndrome. More brain abnormalities were observed in patients without primary Sjögren's syndrome than in those with primary Sjögren's syndrome. Segments lesions (> 3 centrum) were noted in 50% (5/10) of patients without primary Sjögren's syndrome and in 67% (4/6) of patients with primary Sjögren's syndrome. These findings indicate that the clinical characteristics of neuromyelitis optica spectrum disorder patients with and without primary Sjögren's syndrome are similar. However, neuromyelitis optica spectrum disorder patients without primary Sjögren's syndrome have a high frequency of brain abnormalities.

  19. Multiple optical code-label processing using multi-wavelength frequency comb generator and multi-port optical spectrum synthesizer.

    Science.gov (United States)

    Moritsuka, Fumi; Wada, Naoya; Sakamoto, Takahide; Kawanishi, Tetsuya; Komai, Yuki; Anzai, Shimako; Izutsu, Masayuki; Kodate, Kashiko

    2007-06-11

    In optical packet switching (OPS) and optical code division multiple access (OCDMA) systems, label generation and processing are key technologies. Recently, several label processors have been proposed and demonstrated. However, in order to recognize N different labels, N separate devices are required. Here, we propose and experimentally demonstrate a large-scale, multiple optical code (OC)-label generation and processing technology based on multi-port, a fully tunable optical spectrum synthesizer (OSS) and a multi-wavelength electro-optic frequency comb generator. The OSS can generate 80 different OC-labels simultaneously and can perform 80-parallel matched filtering. We also demonstrated its application to OCDMA.

  20. Frequency and spectrum of chlorophyll-deficient mutations in rice after treatment with radiation and alkylating agents

    International Nuclear Information System (INIS)

    Bhan, A.K.; Kaul, M.L.H.

    1976-01-01

    Three varieties of rice were treated with gamma rays and two alkylating agents EMS and DES, separately and in combinations, with a view to finding out the frequency and spectrum of chlorophyll mutations in relation to the genotype and the nature of the mutagen. Chlorophyll mutation frequency was enhanced with increasing dose but dropped at very high doses (doses that induced over 90% seeding lethality in M 1 ). The fall was attributed to either the increased mutated sector and diplontic selection after exposure to very high doses or relatively high resistance of some of the seeds. Among chlorophyll mutants in M 2 induced by radiations as well as alkylating agents, the albina type formed the majority class. EMS induced a significantly higher proportion of albinas than did gamma rays

  1. Control of the long period grating spectrum through low frequency flexural acoustic waves

    International Nuclear Information System (INIS)

    Oliveira, Roberson A; Possetti, Gustavo R C; Kamikawachi, Ricardo C; Fabris, José L; Muller, Marcia; Pohl, Alexandre A P; Marques, Carlos A F; Nogueira, Rogério N; Neves, Paulo T Jr; Cook, Kevin; Canning, John; Bavastri, C

    2011-01-01

    We have shown experimental results of the excitation of long period fiber gratings by means of flexural acoustic waves with a wavelength larger than the grating period, validated by numerical simulations. The effect of the acoustic wave on the grating is modeled with the method of assumed modes, which delivers the strain field inside the grating, then used as the input to the transfer matrix method, needed for calculating the grating spectrum. The experimental and numerical results are found to be in good agreement, even though only the strain-optic effects are taken into account

  2. Mutagenic effects of gamma rays and EMS on frequency and spectrum of chlorophyll mutations in urdbean (Vigna mungo (L.) Hepper)

    International Nuclear Information System (INIS)

    Usharani, K.S.; Ananda Kumar, C.R.

    2015-01-01

    Chlorophyll mutations act as a significant index in the judgment of induced genetic variations in mutagen treated populations. Different types of chlorophyll mutation have been observed in various crop plants. In the current study, the effect of different concentrations (40 kR, 50 kR and 60 kR) of gamma rays, Ethyl Methane Sulphonate (50 mM, 60 mM and 70 mM) in single and combination dose/concentration on the frequency and spectrum of chlorophyll mutation and the effect of VBN 4 urdbean variety to such irradiation dose was observed. Results showed induction of broad spectrum of chlorophyll mutations which included albina, xantha, chlorina and viridis. Among these chlorina type was predominant in all the mutagenic treatments. The albina type of chlorophyll mutants occurred very rarely and was found only at 60 mM of EMS treatment and at 40 kR + 50 mM, 60 kR + 70 mM of combination treatments. Based on the chlorophyll mutation frequency, gamma rays were most effective followed by EMS and combination of treatments. (author)

  3. Altered modulation of gamma oscillation frequency by speed of visual motion in children with autism spectrum disorders.

    Science.gov (United States)

    Stroganova, Tatiana A; Butorina, Anna V; Sysoeva, Olga V; Prokofyev, Andrey O; Nikolaeva, Anastasia Yu; Tsetlin, Marina M; Orekhova, Elena V

    2015-01-01

    Recent studies link autism spectrum disorders (ASD) with an altered balance between excitation and inhibition (E/I balance) in cortical networks. The brain oscillations in high gamma-band (50-120 Hz) are sensitive to the E/I balance and may appear useful biomarkers of certain ASD subtypes. The frequency of gamma oscillations is mediated by level of excitation of the fast-spiking inhibitory basket cells recruited by increasing strength of excitatory input. Therefore, the experimental manipulations affecting gamma frequency may throw light on inhibitory networks dysfunction in ASD. Here, we used magnetoencephalography (MEG) to investigate modulation of visual gamma oscillation frequency by speed of drifting annular gratings (1.2, 3.6, 6.0 °/s) in 21 boys with ASD and 26 typically developing boys aged 7-15 years. Multitaper method was used for analysis of spectra of gamma power change upon stimulus presentation and permutation test was applied for statistical comparisons. We also assessed in our participants visual orientation discrimination thresholds, which are thought to depend on excitability of inhibitory networks in the visual cortex. Although frequency of the oscillatory gamma response increased with increasing velocity of visual motion in both groups of participants, the velocity effect was reduced in a substantial proportion of children with ASD. The range of velocity-related gamma frequency modulation correlated inversely with the ability to discriminate oblique line orientation in the ASD group, while no such correlation has been observed in the group of typically developing participants. Our findings suggest that abnormal velocity-related gamma frequency modulation in ASD may constitute a potential biomarker for reduced excitability of fast-spiking inhibitory neurons in a subset of children with ASD.

  4. ESG Allocations

    Data.gov (United States)

    Department of Housing and Urban Development — This report displays the Emergency Solutions Grants (ESG), formerly Emergency Shelter Grants, allocation by jurisdiction. The website allows users to look at...

  5. A power filter for the detection of burst events based on time-frequency spectrum estimation

    International Nuclear Information System (INIS)

    Guidi, G M; Cuoco, E; Vicere, A

    2004-01-01

    We propose as a statistic for the detection of bursts in a gravitational wave interferometer the 'energy' of the events estimated with a time-dependent calculation of the spectrum. This statistic has an asymptotic Gaussian distribution with known statistical moments, which makes it possible to perform a uniformly most powerful test (McDonough R N and Whalen A D 1995 Detection of Signals in Noise (New York: Academic)) on the energy mean. We estimate the receiver operating characteristic (ROC, from the same book) of this statistic for different levels of the signal-to-noise ratio in the specific case of a simulated noise having the spectral density expected for Virgo, using test signals taken from a library of possible waveforms emitted during the collapse of the core of type II supernovae

  6. Frequency of microbial spectrum of spontaneous bacterial peritonitis in established cirrhosis liver

    International Nuclear Information System (INIS)

    Zaman, A.; Kareem, R.; Khan, E.M.

    2011-01-01

    Background: Spontaneous bacterial peritonitis is one of the most frequent and serious complication in patients with liver cirrhosis and ascites associated with high mortality. Empiric antibiotic therapy should be initiated before the results of ascitic fluid cultures are available, guided by knowledge of the microbial spectrum of spontaneous bacterial peritonitis in a particular population. Methods: This is a descriptive study which was carried out in the Department of Gastroenterology and Hepatology, Postgraduate Medical Institute Hayatabad Medical Complex, Peshawar from January 2007 to December 2007. Fifty consecutive patients of established cirrhosis liver with ascites presenting with suspicion and or risk factors for spontaneous bacterial peritonitis were included in the study after informed consent. All selected patients were subjected to ascitic fluid tap. Twenty ml of ascitic fluid was aspirated in a heparinised disposable syringe; out of it 10 ml was immediately inoculated into blood culture bottle at bedside and sent for bacterial culture along with the remaining 10 ml for routine biochemical and cytological examination. Results: Out of 50 patients, 28 (56%) were diagnosed to have spontaneous bacterial peritonitis or its variants. Classic spontaneous bacterial peritonitis was present in 11 patients (39.28%), 16 (57.14%) patients were found to have culture negative neutrocytic ascites and one patient (3.57%) had bacterascites. Out of 28 cases of spontaneous bacterial peritonitis 12 samples of ascitic fluid showed positive culture reports. E. coli was the most frequently cultured organism isolated in 8 (66.66%) cases, Streptococcus pneumonae in 2 patients (16.66%), Staphylococcus aurus and Klebsiella each in 1 case (8.33%). Conclusion: Spontaneous bacterial peritonitis and its variants is a common complication of liver cirrhosis with ascites. E. coli is the most frequent offending organism in these cases. Knowledge of the microbial spectrum of spontaneous

  7. Quadrupole Transition Spectrum Measurement of Single Ca+ Ions Toward Optical Frequency Standards

    Science.gov (United States)

    2007-01-01

    Gill, 2005, “Optical frequency standards,” Metrologia , 42, S125-S137. [2] M. Kajita, K. Matsubara, Y. Li, K. Hayasaka, and M. Hosokawa, 2004...Interval (PTTI) Meeting 1 10 100 1000 10-15 10-14 10-13 10-12 10-11 Averaging Time [s] R oo t Al la n Va ria nc e 729nm LD by FC8003 729nm LD by

  8. Estimation and Coordination of Sequence Patterns for Frequency Hopping Dynamic Spectrum Access Networks

    Science.gov (United States)

    2014-03-27

    within Gold’s algorithm. Appendix B provides a detailed description of each block’s implementation in VHDL . Appendix C contains the VHDL code for the...provides expected timing restrictions of the VHDL design 28 implemented . Specifically, it establishes the minimum clock period, maximum clock frequency...algorithm is vital for VHDL implementation . The transmitter, or source, utilizes a 10-bit LFSR represented by Figure B.1. First, examine the changes in

  9. Frequency and spectrum of hemoglobinopathy mutations in a Uruguayan pediatric population

    Directory of Open Access Journals (Sweden)

    Julio Da Luz

    2013-01-01

    Full Text Available Hemoglobinopathies are the most common recessive diseases worldwide but their prevalence in Uruguay has not been investigated. In this study, 397 unrelated outpatient children from the Pereira Rosell Hospital Center (CHPR, as well as 31 selected patients with microcytic anemia and 28 β-thalassemia carriers were analyzed for hemoglobinopathies by using biochemical and molecular biology methods. Parametric and non-parametric methods were used to compare the hematological indices between groups of genotypes. Of the 397 patients in the first group, approximately 1% (0.76% HbS and 0.25% β-thalassemia had a mutation in the HBB gene and 3.3% had α-thalassemia. These mutations had a heterogeneous distribution that varied according to individual ancestry. HbS was found exclusively in individuals with declared African ancestry and had a carrier frequency of 2.2%. The frequency of α-thalassemia carriers in outpatients of European and African ancestry was 1.2% and 6.5%, respectively. In contrast, the frequency of α-thalassemia carriers in patients with microcytic anemia was 25.8%, significantly higher (p < 0.01 than that observed in the sample as a whole and in Afro-descendants and Euro-descendants. Significant differences were observed in the hematological parameters between individuals with thalassemia genotypes and those with a normal genotype. These results indicate that hemoglobinopathies are a relevant health problem in Uruguay.

  10. Robust frequency diversity based algorithm for clutter noise reduction of ultrasonic signals using multiple sub-spectrum phase coherence

    Energy Technology Data Exchange (ETDEWEB)

    Gongzhang, R.; Xiao, B.; Lardner, T.; Gachagan, A. [Centre for Ultrasonic Engineering, University of Strathclyde, Glasgow, G1 1XW (United Kingdom); Li, M. [School of Engineering, University of Glasgow, Glasgow, G12 8QQ (United Kingdom)

    2014-02-18

    This paper presents a robust frequency diversity based algorithm for clutter reduction in ultrasonic A-scan waveforms. The performance of conventional spectral-temporal techniques like Split Spectrum Processing (SSP) is highly dependent on the parameter selection, especially when the signal to noise ratio (SNR) is low. Although spatial beamforming offers noise reduction with less sensitivity to parameter variation, phased array techniques are not always available. The proposed algorithm first selects an ascending series of frequency bands. A signal is reconstructed for each selected band in which a defect is present when all frequency components are in uniform sign. Combining all reconstructed signals through averaging gives a probability profile of potential defect position. To facilitate data collection and validate the proposed algorithm, Full Matrix Capture is applied on the austenitic steel and high nickel alloy (HNA) samples with 5MHz transducer arrays. When processing A-scan signals with unrefined parameters, the proposed algorithm enhances SNR by 20dB for both samples and consequently, defects are more visible in B-scan images created from the large amount of A-scan traces. Importantly, the proposed algorithm is considered robust, while SSP is shown to fail on the austenitic steel data and achieves less SNR enhancement on the HNA data.

  11. Frequency spectrum method-based stress analysis for oil pipelines in earthquake disaster areas.

    Directory of Open Access Journals (Sweden)

    Xiaonan Wu

    Full Text Available When a long distance oil pipeline crosses an earthquake disaster area, inertial force and strong ground motion can cause the pipeline stress to exceed the failure limit, resulting in bending and deformation failure. To date, researchers have performed limited safety analyses of oil pipelines in earthquake disaster areas that include stress analysis. Therefore, using the spectrum method and theory of one-dimensional beam units, CAESAR II is used to perform a dynamic earthquake analysis for an oil pipeline in the XX earthquake disaster area. This software is used to determine if the displacement and stress of the pipeline meet the standards when subjected to a strong earthquake. After performing the numerical analysis, the primary seismic action axial, longitudinal and horizontal displacement directions and the critical section of the pipeline can be located. Feasible project enhancement suggestions based on the analysis results are proposed. The designer is able to utilize this stress analysis method to perform an ultimate design for an oil pipeline in earthquake disaster areas; therefore, improving the safe operation of the pipeline.

  12. Frequency spectrum method-based stress analysis for oil pipelines in earthquake disaster areas.

    Science.gov (United States)

    Wu, Xiaonan; Lu, Hongfang; Huang, Kun; Wu, Shijuan; Qiao, Weibiao

    2015-01-01

    When a long distance oil pipeline crosses an earthquake disaster area, inertial force and strong ground motion can cause the pipeline stress to exceed the failure limit, resulting in bending and deformation failure. To date, researchers have performed limited safety analyses of oil pipelines in earthquake disaster areas that include stress analysis. Therefore, using the spectrum method and theory of one-dimensional beam units, CAESAR II is used to perform a dynamic earthquake analysis for an oil pipeline in the XX earthquake disaster area. This software is used to determine if the displacement and stress of the pipeline meet the standards when subjected to a strong earthquake. After performing the numerical analysis, the primary seismic action axial, longitudinal and horizontal displacement directions and the critical section of the pipeline can be located. Feasible project enhancement suggestions based on the analysis results are proposed. The designer is able to utilize this stress analysis method to perform an ultimate design for an oil pipeline in earthquake disaster areas; therefore, improving the safe operation of the pipeline.

  13. Spectrum 101: An Introduction to Spectrum Management

    Science.gov (United States)

    2004-03-01

    produces a Joint Restricted Frequency List (JRFL). The JFRL consolidates and classifies the spectrum uses that are most critical to operations and to...Management Office JRFL Joint Restricted Frequency List JSC Joint Spectrum Center JSIR Joint Spectrum Interference Resolution JSME Joint Spectrum...Multifunctional Information Distribution System MILSATCOM Military Satellite Communications MOA Memorandum of Agreement MRFL Master Radio Frequency

  14. Frequency and spectrum of abnormalities in the bone marrow of the wrist: MR imaging findings

    International Nuclear Information System (INIS)

    Alam, F.; Schweitzer, M.E.; Malat, J.; Hussain, S.M.; Rijksuniversiteit Leiden

    1999-01-01

    Objective. To describe the frequency of marrow abnormalities on wrist MR imaging and the MR findings of these various abnormalities.Design and patients. Five hundred and nineteen patients were studied at 1.5 T. Two observers recorded the presence and location of avascular necrosis, occult fractures and arthritic edema [focal osteoarthritis, ulnolunate abutment, rheumatoid arthritis, septic arthritis, gouty arthritis and scapholunate advanced collapse (SLAC)].Results and conclusion. One hundred and eighty-seven (36%) patients demonstrated marrow abnormalities in the wrist, of which 101 were diagnosed as arthritis [64 (34%) as focal osteoarthritis, 17 (9%) as ulnolunate abutment, 15 (8%) as rheumatoid arthritis, 2 as septic arthritis, 2 as SLAC, and 1 as gouty arthritis]. Seventy-two patients had occult fractures and in 27 patients avascular necrosis was seen. MR imaging can reveal various abnormalities in bone marrow of the wrist when findings on radiography are normal or equivocal. (orig.)

  15. Frequency and spectrum of abnormalities in the bone marrow of the wrist: MR imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Alam, F.; Schweitzer, M.E. (Thomas Jefferson Univ., Philadelphia, PA (United States). Dept. of Radiology); Li Xiaoxian (Dept. of Radiology, Tangshan Gongren Hospital, Tangshan (China)); Malat, J. (Department of Radiology, Naples Radiologists, Naples (Italy)); Hussain, S.M. (Thomas Jefferson Univ., Philadelphia, PA (United States). Dept. of Radiology Rijksuniversiteit Leiden (Netherlands). Dept. of Diagnostic Radiology)

    1999-06-01

    Objective. To describe the frequency of marrow abnormalities on wrist MR imaging and the MR findings of these various abnormalities.Design and patients. Five hundred and nineteen patients were studied at 1.5 T. Two observers recorded the presence and location of avascular necrosis, occult fractures and arthritic edema [focal osteoarthritis, ulnolunate abutment, rheumatoid arthritis, septic arthritis, gouty arthritis and scapholunate advanced collapse (SLAC)].Results and conclusion. One hundred and eighty-seven (36%) patients demonstrated marrow abnormalities in the wrist, of which 101 were diagnosed as arthritis [64 (34%) as focal osteoarthritis, 17 (9%) as ulnolunate abutment, 15 (8%) as rheumatoid arthritis, 2 as septic arthritis, 2 as SLAC, and 1 as gouty arthritis]. Seventy-two patients had occult fractures and in 27 patients avascular necrosis was seen. MR imaging can reveal various abnormalities in bone marrow of the wrist when findings on radiography are normal or equivocal. (orig.) With 17 figs., 13 refs.

  16. Resource Distribution Approaches in Spectrum Sharing Systems

    Directory of Open Access Journals (Sweden)

    Friedrich K. Jondral

    2008-05-01

    Full Text Available It is increasingly difficult to satisfy growing demands for spectrum with the conventional policy of fixed spectrum allocation. To overcome this problem, flexible/dynamic spectrum sharing methods that can significantly improve spectrum utilization of the spectrum have gained increasing interest recently. This paper presents two dynamic spectrum sharing approaches, a centralized and a decentralized one. The centralized approach is based on hierarchical trading. Each level of hierarchy is composed of “markets” that are associated with a certain spatial area and trading occurrence frequency, whereas area size and trading occurrence frequency depend on the hierarchy level. The decentralized approach is based on game-theory. There, it is assumed that the operators are averse to unequal payoffs and act unselfishly, enabling a stable and sustainable community. Numerical results show that, in the observed scenario, both proposals outperform the reference case of fixed resource allocation significantly in terms of utilized bandwidth. Whereas, negotiation costs for spectrum brokerage appear in the centralized approach, nonnegligible amounts of spectrum are lost in the decentralized approach due to collisions. Thus, a hybrid of centralized and decentralized approach that exploits the benefits of both is also considered.

  17. Tapering the sky response for angular power spectrum estimation from low-frequency radio-interferometric data.

    Science.gov (United States)

    Choudhuri, Samir; Bharadwaj, Somnath; Roy, Nirupam; Ghosh, Abhik; Ali, Sk Saiyad

    2016-06-11

    It is important to correctly subtract point sources from radio-interferometric data in order to measure the power spectrum of diffuse radiation like the Galactic synchrotron or the Epoch of Reionization 21-cm signal. It is computationally very expensive and challenging to image a very large area and accurately subtract all the point sources from the image. The problem is particularly severe at the sidelobes and the outer parts of the main lobe where the antenna response is highly frequency dependent and the calibration also differs from that of the phase centre. Here, we show that it is possible to overcome this problem by tapering the sky response. Using simulated 150 MHz observations, we demonstrate that it is possible to suppress the contribution due to point sources from the outer parts by using the Tapered Gridded Estimator to measure the angular power spectrum C ℓ of the sky signal. We also show from the simulation that this method can self-consistently compute the noise bias and accurately subtract it to provide an unbiased estimation of C ℓ .

  18. Maintainability allocation

    International Nuclear Information System (INIS)

    Guyot, Christian.

    1980-06-01

    The author gives the general lines of a method for the allocation and for the evaluation of maintainability of complex systems which is to be developed during the conference. The maintainability objective is supposed to be formulated under the form of a mean time to repair (M.T.T.R.) [fr

  19. Spectrum and Frequency of Mutations Induced by Gamma Radiations in Three Varieties of Nigerian Sesame (Sesamum indicum L.

    Directory of Open Access Journals (Sweden)

    Muhammad Liman MUHAMMAD

    2018-03-01

    Full Text Available Insufficient genetic variability is one of the major problems of plant breeding programmes, especially in sesame. Gamma radiation has been reported to be very effective in creating genetic variability in plants. Three varieties of Nigerian sesame were assessed for spectrum and frequency of mutation induced by Gamma radiations in M1 and M2 generations. The varieties (NCRIBEN-04E, NCRIBEN-01M and NCRIBEN-03L were treated with four different doses of gamma rays (250, 350, 450 and 550 Gy. The treated and untreated seeds (control were sown in planting bags (under field condition to raise M1 plants. Four treatments: V1D5, V2D3, V3D2 and V3D4 (from M1 plants were selected and bulked to obtain M2 populations. The results of M1 revealed four mutant fruit traits: multicarpellate capsule, multiple capsule per leaf axil, indehiscent capsule and terminal capsules. The highest frequencies of the traits in M1 generation were 2.50×10-2, 9.17×10-2, 1.67×10-2and3.33×10-2 respectively. The highest branching (7 was from NCRIBEN-01M, while the least (2 was from NCRIBEN-04E. The M2 plants were grouped into eight M2 lines. The dose range (250-550 Gy was proved to be effective in inducing viable mutations in sesame.

  20. Changing of Bacteria Catalase Activity Under the Influence of Electro-Magnetic Radiation on a Frequency of Nitric Oxide Absorption and Radiation Molecular Spectrum

    Directory of Open Access Journals (Sweden)

    G.M. Shub

    2009-09-01

    Full Text Available The dynamics of catalase activity degree changing in Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa is described under the influence of electro-magnetic radiation on a frequency of nitric oxide absorption and radiation molecular spectrum. The panoramic spectrometric measuring complex, developed in Central Scientific Research Institute of measuring equipment Public corporation, Saratov, was used while carrying out the research. Electromagnetic vibrations of extremely high frequencies were stimulated in this complex imitating the structure of nitric oxide absorption and radiation molecular spectrum. The growth of activity of the mentioned enzyme of the strains under research was detected. The most significant changes were observed under 60-minutes exposure.

  1. Microbial resistance and frequency of extended-spectrum beta-lactamase (ESBL in isolated from blood cultures

    Directory of Open Access Journals (Sweden)

    Ruan Carlos Gomes da Silva

    2014-12-01

    Full Text Available Introduction:The emergence and spread of isolated carriers of extended-spectrum beta-lactamase (ESBL have complicated the treatment of nosocomial infections, since its production is not easily identified by the sensitivity tests, routinely performed in clinical laboratories, leading to difficulties in the hospital control of resistant microorganisms and antibiotics misuse.Objective:The objective of this study was to analyze the resistance profile and the frequency of ESBL in Gram-negative bacteria isolated from blood cultures. A hundred bacterial samples from blood cultures of adult patients were analyzed, which were phenotypically identified by biochemical tests of carbohydrates fermentation and submitted to determination of the resistance profile by disc diffusion test and ESBL screening by disc approximation and disc replacement methods.Results:Among the bacterial samples tested, 30 were identified as Gram-negative bacteria, predominantly by Proteus mirabilis, Pantoea agglomerans, and Escherichia coli. Of these, 73.33% were positive for the detection of ESBL by phenotypic tests, and was found mainly in Pantoea agglomerans, Proteus mirabilis, and Enterobacter cloacae.Conclusion:The increase in the occurrence of ESBL in different Enterobacteriaceae shows the importance of the amplification of detection in other species than Escherichia coli or Klebsiella sp., so that the assistance to the patient is not restrained, since these resistant bacteria cannot be detected by the laboratories. Considering the frequency of ESBL in this study, we highlight the importance of its detection, aiming to its contribution to the development of improvements in the health care policies of hospitals.

  2. Multi-Frequency Monitoring of the Flat Spectrum Radio Quasar PKS 1222+216 in 2008–2015

    Directory of Open Access Journals (Sweden)

    Ivan Troitskiy

    2016-11-01

    Full Text Available We analyze the broadband activity of the flat spectrum radio quasar PKS 1222+216 from 2008 to 2015 using multi-frequency monitoring which involves γ-ray data from the Fermi Large Area Telescope, total intensity and linear polarization observations from different optical telescopes in R band, and imaging of the inner jet structure with the Very Long Baseline Array (VLBA at 43 GHz. During the observations, the source showed several dramatic flares at γ rays and optical bands, with the rising branch of a γ-ray flare accompanied by a rapid rotation of the polarization position angle (EVPA, a fast increase of the degree of polarization in the optical band, brightening of the VLBI core, and appearance of a new superluminal component in the parsec-scale jet. The rapid variability of the optical linear polarization may be explained by a strong turbulence in the jet plasma. We find a correlation between the γ rays, optical R band, and 43 GHz variability on a long-term scale (months and years, and a good general alignment between EVPAs in R band and at 43 GHz, while the correlation between short-term variations (days and weeks is weaker. Synchronous activity across the bands supports the idea that the emission regions responsible for the γ-ray and optical flares are co-spatial and located in the vicinity of the mm-wave core of the parsec-scale jet. However, these connections do not completely explain the challenging behaviour of PKS 1222+216, since there are some γ-ray flares which are not accompanied by jet events, and vice versa. We need a continuation of multi-frequency monitoring along with high resolution imaging of the parsec-scale jet to understand in detail the origin of high energy emission in blazars.

  3. Frequency of brain MRI abnormalities in neuromyelitis optica spectrum disorder at presentation: A cohort of Latin American patients.

    Science.gov (United States)

    Carnero Contentti, Edgar; Daccach Marques, Vanessa; Soto de Castillo, Ibis; Tkachuk, Veronica; Antunes Barreira, Amilton; Armas, Elizabeth; Chiganer, Edson; de Aquino Cruz, Camila; Di Pace, José Luis; Hryb, Javier Pablo; Lavigne Moreira, Carolina; Lessa, Carmen; Molina, Omaira; Perassolo, Monica; Soto, Arnoldo; Caride, Alejandro

    2018-01-01

    Brain magnetic resonance imaging (BMRI) lesions were classically not reported in neuromyelitis optica (NMO). However, BMRI lesions are not uncommon in NMO spectrum disorder (NMOSD) patients. To report BMRI characteristic abnormalities (location and configuration) in NMOSD patients at presentation. Medical records and BMRI characteristics of 79 patients with NMOSD (during the first documented attack) in Argentina, Brazil and Venezuela were reviewed retrospectively. BMRI abnormalities were observed in 81.02% of NMOSD patients at presentation. Forty-two patients (53.1%) showed typical-NMOSD abnormalities. We found BMRI abnormalities at presentation in the brainstem/cerebellum (n = 26; 32.9%), optic chiasm (n = 16; 20.2%), area postrema (n = 13; 16.4%), thalamus/hypothalamus (n = 11; 13.9%), corpus callosum (n = 11; 13.9%), periependymal-third ventricle (n = 9; 11.3%), corticospinal tract (n = 7; 8.8%), hemispheric white matter (n = 1; 1.2%) and nonspecific areas (n = 49; 62.03%). Asymptomatic BMRI lesions were more common. The frequency of brain MRI abnormalities did not differ between patients who were positive and negative for aquaporin 4 antibodies at presentation. Typical brain MRI abnormalities are frequent in NMOSD at disease onset. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. The frequency and spectrum of thymus 2-[fluorine-18] fluoro-2-deoxy-D-glucose uptake patterns in hyperthyroidism patients.

    Science.gov (United States)

    Chen, Yen-Kung; Yeh, Chia-Lu; Chen, Yen-Ling; Wang, Su-Chen; Cheng, Ru-Hwa; Kao, Pan-Fu

    2011-10-01

    Thymic hyperplasia is associated with hyperthyroidism. Increased thymus 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) uptake in hyperthyroidism patients has been reported. The aim of this study was to analyze the FDG positron emission tomography (PET) thymus uptake spectrum in patients with active hyperthyroidism with correlation with serum hormones. The prospective study included FDG PET scans from 65 hyperthyroidism patients and 30 subjects with euthyroid status as control group. The intensity of FDG uptake in thyroid and thymus regions was graded subjectively on a five-point scale and semi-quantitatively by measuring standard uptake value (SUV). Correlation coefficient between thymus SUV and serum thyroxine, triiodothyronine, thyrotropin, thyroid peroxidase antibodies (TPO Ab), thyrotropin receptor autoantibody (TR Ab), and thymulin were analyzed. Among 65 hyperthyroidism patients, 30 (46.2%) and 39 (60%) patients showed thyroid and thymus FDG uptake, respectively. The frequency of thymus uptake FDG was high in patients younger than age 40 (28/31, 90.3%). The patterns of the thymic FDG uptake include inverted V or triangular, separated triangular, united nontriangular, unilateral right or left extension, and focal midline. Focal midline FDG uptake was the most common pattern (15/39, 38.5%). None of the control group showed thymus FDG uptake. The correlation coefficient between the FDG uptake SUV levels in thymus and serum hormones, thyrotropin, TPO Ab, TR Ab, and thymulin levels were all low (P > .05). In FDG PET scan, thymus activity was common in hyperthyroidism patients; this should not be misdiagnosed as a malignancy in patients exhibiting weight loss. Copyright © 2011 AUR. Published by Elsevier Inc. All rights reserved.

  5. Investigations on the relationship between power spectrum and signal-to-noise ratio of frequency-swept pulses

    International Nuclear Information System (INIS)

    Zhang Zhuhong; Fan Diayuan

    1993-01-01

    The criterion for obtaining compressed chirp pulses with high signal-to-noise ratio is the shape of the power spectrum, a chirp pulse of Gaussian shaped power spectrum without modulation is needed in CPA system to get the clean compressed pulses. 4 refs., 2 figs

  6. Frequency characteristic measurement of a fiber optic gyroscope using a correlation spectrum analysis method based on a pseudo-random sequence

    International Nuclear Information System (INIS)

    Li, Yang; Chen, Xingfan; Liu, Cheng

    2015-01-01

    The frequency characteristic is an important indicator of a system’s dynamic performance. The identification of a fiber optic gyroscope (FOG)’s frequency characteristic using a correlation spectrum analysis method based on a pseudo-random sequence is proposed. Taking the angle vibrator as the source of the test rotation stimulation and a pseudo-random sequence as the test signal, the frequency characteristic of a FOG is calculated according to the power spectral density of the rotation rate signal and the cross-power spectral density of the FOG’s output signal and rotation rate signal. A theoretical simulation is done to confirm the validity of this method. An experiment system is built and the test results indicate that the measurement error of the normalized amplitude–frequency response is less than 0.01, that the error of the phase–frequency response is less than 0.3 rad, and the overall measurement accuracy is superior to the traditional frequency-sweep method. By using this method, the FOG’s amplitude–frequency response and phase–frequency response can be measured simultaneously, quickly, accurately, and with a high frequency resolution. The described method meets the requirements of engineering applications. (paper)

  7. Estimation of Scatterer Diameter by Normalized Power Spectrum of High-Frequency Ultrasonic RF Echo for Assessment of Red Blood Cell Aggregation

    Science.gov (United States)

    Fukushima, Taku; Hasegawa, Hideyuki; Kanai, Hiroshi

    2011-07-01

    Red blood cell (RBC) aggregation, as one of the determinants of blood viscosity, plays an important role in blood rheology, including the condition of blood. RBC aggregation is induced by the adhesion of RBCs when the electrostatic repulsion between RBCs weakens owing to increases in protein and saturated fatty acid levels in blood, excessive RBC aggregation leads to various circulatory diseases. This study was conducted to establish a noninvasive quantitative method for assessment of RBC aggregation. The power spectrum of ultrasonic RF echoes from nonaggregating RBCs, which shows the frequency property of scattering, exhibits Rayleigh behavior. On the other hand, ultrasonic RF echoes from aggregating RBCs contain the components of reflection, which have no frequency dependence. By dividing the measured power spectrum of echoes from RBCs in the lumen by that of echoes from a posterior wall of the vein in the dorsum manus, the attenuation property of the propagating medium and the frequency responses of transmitting and receiving transducers are removed from the former spectrum. RBC aggregation was assessed by the diameter of a scatterer, which was estimated by minimizing the square difference between the measured normalized power spectrum and the theoretical power spectrum. In this study, spherical scatterers with diameters of 5, 11, 15, and 30 µm were measured in basic experiments. The estimated scatterer diameters were close to the actual diameters. Furthermore, the transient change of the scatterer diameters were measured in an in vivo experiment with respect to a 24-year-old healthy male during the avascularization using a cuff. The estimated diameters (12-22 µm) of RBCs during avascularization were larger than the diameters (4-8 µm) at rest and after recirculation. These results show the possibility of the use of the proposed method for noninvasive assessment of RBC aggregation.

  8. Frequency-resolved measurement of the orbital angular momentum spectrum of femtosecond ultra-broadband optical-vortex pulses based on field reconstruction

    International Nuclear Information System (INIS)

    Yamane, Keisaku; Yang, Zhili; Toda, Yasunori; Morita, Ryuji

    2014-01-01

    We propose a high-precision method for measuring the orbital angular momentum (OAM) spectrum of ultra-broadband optical-vortex (OV) pulses from fork-like interferograms between OV pulses and a reference plane-wave pulse. It is based on spatial reconstruction of the electric fields of the pulses to be measured from the frequency-resolved interference pattern. Our method is demonstrated experimentally by obtaining the OAM spectra for different spectral components of the OV pulses, enabling us to characterize the frequency dispersion of the topological charge of the OAM spectrum by a simple experimental setup. Retrieval is carried out in quasi-real time, allowing us to investigate OAM spectra dynamically. Furthermore, we determine the relative phases (including the sign) of the topological-charge-resolved electric-field amplitudes, which are significant for evaluating OVs or OV pulses with arbitrarily superposed modes. (paper)

  9. A study of the chlorine nuclear quadrupole resonance frequency spectrum in potassium hexachloro-osmate by Fourier transform methods

    International Nuclear Information System (INIS)

    Mintz, D.J.; Armstrong, R.L.

    1980-01-01

    A study of the chlorine nuclear quadrupole resonance spectrum of K 2 OsCl 6 in the vicinity of the structural phase transition using Fourier transform techniques is reported. At high temperatures a single symmetric line spectrum is observed as expected from the high temperature cubic antifluorite structure. Below T(sub)c = 45 K the two symmetric line spectrum characteristic of a tetragonal distortion is seen. At intermediate temperatures, 45< T<150 K the spectrum consists of a single asymmetric line. A detailed analysis reveals that for the single crystal sample the asymmetric line is composed of two symmetric components, a main line, and a weak satellite shifted - 1.5 kHz relative to the main line. This feature is unaffected by changes in temperature near T(sub)c. It is attributed to the influence of interstitial impurities on neighbouring chlorine ions. For the powder sample, the asymmetry is qualitatively different. A detailed analysis shows that the line is a superposition of three components. In addition to the two components present in the single crystal, a third, broad component develops as the temperature approaches T(sub)c. This feature of the spectrum is the cluster induced order-disorder manifestation of the local dynamics. The most probable reason that this third component is not observed in the single crystal spectrum is because it is too broad due to a difference in the detailed dynamics of two samples. (auth)

  10. Investigation of the Mössbauer Spectrum Quality as a Dependence on the Frequency of the Velocity Signal

    Science.gov (United States)

    Pechousek, J.; Prochazka, R.; Cuda, J.; Frydrych, J.; Jancik, D.

    2010-07-01

    This paper is focused on a quality characterizing the Mössbauer spectra measured for various frequencies of the velocity signal. Standard electromechanical double-loudspeaker drive and digital PID velocity controller were used for calibration spectra measurement in the frequency interval from 4 up to 100 Hz. Several parameters were evaluated for recommendation of the suitable velocity signal frequency.

  11. Interaction between pancreatic β cell and electromagnetic fields: A systematic study toward finding the natural frequency spectrum of β cell system.

    Science.gov (United States)

    Farashi, Sajjad

    2017-01-01

    Interaction between biological systems and environmental electric or magnetic fields has gained attention during the past few decades. Although there are a lot of studies that have been conducted for investigating such interaction, the reported results are considerably inconsistent. Besides the complexity of biological systems, the important reason for such inconsistent results may arise due to different excitation protocols that have been applied in different experiments. In order to investigate carefully the way that external electric or magnetic fields interact with a biological system, the parameters of excitation, such as intensity or frequency, should be selected purposefully due to the influence of these parameters on the system response. In this study, pancreatic β cell, the main player of blood glucose regulating system, is considered and the study is focused on finding the natural frequency spectrum of the system using modeling approach. Natural frequencies of a system are important characteristics of the system when external excitation is applied. The result of this study can help researchers to select proper frequency parameter for electrical excitation of β cell system. The results show that there are two distinct frequency ranges for natural frequency of β cell system, which consist of extremely low (or near zero) and 100-750 kHz frequency ranges. There are experimental works on β cell exposure to electromagnetic fields that support such finding.

  12. Radio quite site qualification for the Brasilian Southern Space Observatory by monitoring the low frequency 10-240 MHz Eletromagnetic Spectrum

    Science.gov (United States)

    da Rosa, Guilherme Simon; Schuch, Nelson Jorge; Espindola Antunes, Cassio; Gomes, Natanael

    The monitoring of the level of the radio interference in the Site of the Brazilian Southern Space Observatory - SSO/CRS/CIE/INPE - MCT, (29S, 53W), São Martinho da Serra, RS, in south a of Brazil, aims to gather spectral data for the Observatory's Site qualification as a radio quite site for installation of Radio Astronomy instrumentation, free of radio noise. The determination of the radio interference level is being conducted by using a spectrum analyzer and Omni directional antennas remotely controlled through a GPIB interface, via IEEE 488 bus, and programs written in C language. That procedure allows the scanning of the Electromagnetic Spectrum power over the examined frequency range from 10 - 240MHz. The methodology for these tests was to amplify the radio signal from the antenna by a block amplifier. Subsequently, the received signals are evaluated by the spectrum analyzer. A dedicated PC computer is used for the control and data acquisition, with the developed software. The data are instantly stored in digital format and remotely transferred via VNC software from the SSO-Observatory Site to the Radio Frequency and Telecommunication Laboratory at the Southern Regional Space Research Center - CRS/CIE/INPE - MCT, in Santa Maria, RS, for analysis and storage on the radio interference data base for long period. It is compared the SSO's Electromagnetic Spectrum data obtained since the beginning of the 1990's decade, before the Site constructions, with the current observed data. Some radio transmissions were found in the observed frequency range due to some local FMs, mostly between 93.5 MHz to 105.7 MHz, which were observed in previous monitoring. A good evidence of the site quality is the fact that the power of the Electromagnetic Spectrum is much lower than that measured at the Radio Frequency and Telecommunication Laboratory, in Santa Maria, RS, where the signals do not exceed -60 dB. On the Site of the SSO, due to the low power observed, weak radio signals

  13. Residency Allocation Database

    Data.gov (United States)

    Department of Veterans Affairs — The Residency Allocation Database is used to determine allocation of funds for residency programs offered by Veterans Affairs Medical Centers (VAMCs). Information...

  14. Evidence of dithionite contribution to the low-frequency resonance Raman spectrum of reduced and mixed-valence cytochrome c oxidase.

    Science.gov (United States)

    Centeno, J A

    1992-02-01

    The resonance Raman spectra of deoxygenated solutions of mixed-valence cyanide-bound and fully reduced cytochrome oxidase derivatives that have been reduced in the presence of aqueous or solid sodium dithionite exhibit two new low-frequency lines centered at 474 and 590 cm-1. These lines were not observed when the reductant system was changed to a solution containing ascorbate and N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD). Under enzyme turnover conditions, the addition of dithionite to the reoxidized protein (the 428-nm or "oxygenated" form) increases the intensity of these lines, while reoxidation and rereduction of the enzyme in the presence of ascorbate/TMPD resulted in the absence of both lines. Our data suggest that both lines must have contributions from species formed from aqueous dithionite, presumably the SO2 species, since these two lines are also observed in the Raman spectrum of a solution of aqueous dithionite, but not in the spectrum of an ascorbate/TMPD solution. Since heme metal-ligand stretch vibrations are expected to appear in the low-frequency region from 215 to 670 cm-1, our results indicate that special care should be exercised during the interpretation of the cytochrome a3 resonance Raman spectrum.

  15. An Electromagnetic Spectrum for Millennial Students: Teaching Light, Color, Energy, and Frequency Using the Electronic Devices of Our Time

    Science.gov (United States)

    Murphy, Maureen Kendrick

    2010-01-01

    In this article, a comparison of student learning outcomes is made in sophomore-level physical science classes using a "traditional" pedagogical approach versus a "modern" approach. Specifically, when students were taught the electromagnetic spectrum using diagrams and examples that incorporate technological advances and electronic devices of our…

  16. 47 CFR Figure 3 to Subpart N of... - Example of Ideal EPIRB Spectrum

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Example of Ideal EPIRB Spectrum 3 Figure 3 to Subpart N of Part 2 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL FREQUENCY ALLOCATIONS AND... Position Indicating Radiobeacons (EPIRBs) Pt. 2, Subpt. N, Fig. 3 Figure 3 to Subpart N of Part 2—Example...

  17. Transport Infrastructure Slot Allocation

    NARCIS (Netherlands)

    Koolstra, K.

    2005-01-01

    In this thesis, transport infrastructure slot allocation has been studied, focusing on selection slot allocation, i.e. on longer-term slot allocation decisions determining the traffic patterns served by infrastructure bottlenecks, rather than timetable-related slot allocation problems. The

  18. Analysis Framework for Opportunistic Spectrum OFDMA and its Application to the IEEE 802.22 Standard

    OpenAIRE

    Park, Jihoon; Pawełczak, Przemysław; Grønsund, Pål; Čabrić, Danijela

    2010-01-01

    We present an analytical model that enables throughput evaluation of Opportunistic Spectrum Orthogonal Frequency Division Multiple Access (OS-OFDMA) networks. The core feature of the model, based on a discrete time Markov chain, is the consideration of different channel and subchannel allocation strategies under different Primary and Secondary user types, traffic and priority levels. The analytical model also assesses the impact of different spectrum sensing strategies on the throughput of OS...

  19. THE HYPERFINE STRUCTURE OF THE ROTATIONAL SPECTRUM OF HDO AND ITS EXTENSION TO THE THz REGION: ACCURATE REST FREQUENCIES AND SPECTROSCOPIC PARAMETERS FOR ASTROPHYSICAL OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Cazzoli, Gabriele; Lattanzi, Valerio; Puzzarini, Cristina [Dipartimento di Chimica “Giacomo Ciamician”, Università di Bologna, Via Selmi 2, I-40126 Bologna (Italy); Alonso, José Luis [Grupo de Espectroscopía Molecular (GEM), Unidad Asociada CSIC, Edificio Quifima, Laboratorios de Espectroscopia y Bioespectroscopia, Parque Científico UVa, Universidad de Valladolid, E-47005 Valladolid (Spain); Gauss, Jürgen, E-mail: cristina.puzzarini@unibo.it [Institut für Physikalische Chemie, Universität Mainz, D-55099 Mainz (Germany)

    2015-06-10

    The rotational spectrum of the mono-deuterated isotopologue of water, HD{sup 16}O, has been investigated in the millimeter- and submillimeter-wave frequency regions, up to 1.6 THz. The Lamb-dip technique has been exploited to obtain sub-Doppler resolution and to resolve the hyperfine (hf) structure due to the deuterium and hydrogen nuclei, thus enabling the accurate determination of the corresponding hf parameters. Their experimental determination has been supported by high-level quantum-chemical calculations. The Lamb-dip measurements have been supplemented by Doppler-limited measurements (weak high-J and high-frequency transitions) in order to extend the predictive capability of the available spectroscopic constants. The possibility of resolving hf splittings in astronomical spectra has been discussed.

  20. Origin of absorption peaks in reflection loss spectrum in Ku- frequency band of Co-Zr substituted strontium hexaferrites prepared using sucrose precursor

    Energy Technology Data Exchange (ETDEWEB)

    Narang, Sukhleen Bindra, E-mail: sukhleen2@yahoo.com [Department of Electronics Technology, Guru Nanak Dev University, Amritsar (India); Pubby, Kunal, E-mail: kunalpubby02@gmail.com [Department of Electronics Technology, Guru Nanak Dev University, Amritsar (India); Chawla, S.K., E-mail: sschawla118@gmail.com [Department of Chemistry, Centre for Advanced Studies-I, Guru Nanak Dev University, Amritsar (India); Kaur, Prabhjyot, E-mail: prabhjyot.2525@gmail.com [Department of Chemistry, Centre for Advanced Studies-I, Guru Nanak Dev University, Amritsar (India)

    2017-03-15

    This study presents the detailed explanation of the factors, contributing towards the absorption peaks in reflection loss spectrum of hexaferrites. Cobalt-Zirconium substituted strontium hexaferrites, synthesized using sucrose precursor sol-gel technique, were analyzed in 12.4–18 GHz frequency range. The concepts of impedance matching through quarter wavelength condition, complex thickness, dielectric phase angle and attenuation constant have been used to determine the location as well as intensity of absorption peaks. This study also demonstrates the potential application of three compositions of this series with doping content (x)==0.0, 0.6 and 0.8 as an effective microwave absorbers in Ku-frequency band. - Highlights: • EM analysis of Sr Hexaferrites in Ku-band. • Factors towards absorption peak intensity & location.

  1. A revised method of presenting wavenumber-frequency power spectrum diagrams that reveals the asymmetric nature of tropical large-scale waves

    Energy Technology Data Exchange (ETDEWEB)

    Chao, Winston C. [NASA/Goddard Space Flight Center, Global Modeling and Assimilation Office, Mail Code 610.1, Greenbelt, MD (United States); Yang, Bo; Fu, Xiouhua [University of Hawaii at Manoa, School of Ocean and Earth Science and Technology, International Pacific Research Center, Honolulu, HI (United States)

    2009-11-15

    The popular method of presenting wavenumber-frequency power spectrum diagrams for studying tropical large-scale waves in the literature is shown to give an incomplete presentation of these waves. The so-called ''convectively coupled Kelvin (mixed Rossby-gravity) waves'' are presented as existing only in the symmetric (anti-symmetric) component of the diagrams. This is obviously not consistent with the published composite/regression studies of ''convectively coupled Kelvin waves,'' which illustrate the asymmetric nature of these waves. The cause of this inconsistency is revealed in this note and a revised method of presenting the power spectrum diagrams is proposed. When this revised method is used, ''convectively coupled Kelvin waves'' do show anti-symmetric components, and ''convectively coupled mixed Rossby-gravity waves (also known as Yanai waves)'' do show a hint of symmetric components. These results bolster a published proposal that these waves should be called ''chimeric Kelvin waves,'' ''chimeric mixed Rossby-gravity waves,'' etc. This revised method of presenting power spectrum diagrams offers an additional means of comparing the GCM output with observations by calling attention to the capability of GCMs to correctly simulate the asymmetric characteristics of equatorial waves. (orig.)

  2. Determining In Situ Protein Conformation and Orientation from the Amide-I Sum-Frequency Generation Spectrum: Theory and Experiment

    NARCIS (Netherlands)

    Roeters, S.J.; van Dijk, C.N.; Torres Knoop, A.; Backus, E.H.G.; Campen, R.K.; Bonn, M.; Woutersen, S.

    2013-01-01

    Vibrational sum-frequency generation (VSFG) spectra of the amide-I band of proteins can give detailed insight into biomolecular processes near membranes. However, interpreting these spectra in terms of the conformation and orientation of a protein can be difficult, especially in the case of complex

  3. Evaluation of the Fourier Frequency Spectrum Peaks of Milk Electrical Conductivity Signals as Indexes to Monitor the Dairy Goats’ Health Status by On-Line Sensors

    Directory of Open Access Journals (Sweden)

    Mauro Zaninelli

    2015-08-01

    Full Text Available The aim of this study is a further characterization of the electrical conductivity (EC signal of goat milk, acquired on-line by EC sensors, to identify new indexes representative of the EC variations that can be observed during milking, when considering not healthy (NH glands. Two foremilk gland samples from 42 Saanen goats, were collected for three consecutive weeks and for three different lactation stages (LS: 0–60 Days In Milking (DIM; 61–120 DIM; 121–180 DIM, for a total amount of 1512 samples. Bacteriological analyses and somatic cells counts (SCC were used to define the health status of the glands. With negative bacteriological analyses and SCC < 1,000,000 cells/mL, glands were classified as healthy. When bacteriological analyses were positive or showed a SCC > 1,000,000 cells/mL, glands were classified as NH. For each milk EC signal, acquired on-line and for each gland considered, the Fourier frequency spectrum of the signal was calculated and three representative frequency peaks were identified. To evaluate data acquired a MIXED procedure was used considering the HS, LS and LS × HS as explanatory variables in the statistical model.Results showed that the studied frequency peaks had a significant relationship with the gland’s health status. Results also explained how the milk EC signals’ pattern change in case of NH glands. In fact, it is characterized by slower fluctuations (due to the lower frequencies of the peaks and by an irregular trend (due to the higher amplitudes of all the main frequency peaks. Therefore, these frequency peaks could be used as new indexes to improve the performances of algorithms based on multivariate models which evaluate the health status of dairy goats through the use of gland milk EC sensors.

  4. Evaluation of the Fourier Frequency Spectrum Peaks of Milk Electrical Conductivity Signals as Indexes to Monitor the Dairy Goats’ Health Status by On-Line Sensors

    Science.gov (United States)

    Zaninelli, Mauro; Agazzi, Alessandro; Costa, Annamaria; Tangorra, Francesco Maria; Rossi, Luciana; Savoini, Giovanni

    2015-01-01

    The aim of this study is a further characterization of the electrical conductivity (EC) signal of goat milk, acquired on-line by EC sensors, to identify new indexes representative of the EC variations that can be observed during milking, when considering not healthy (NH) glands. Two foremilk gland samples from 42 Saanen goats, were collected for three consecutive weeks and for three different lactation stages (LS: 0–60 Days In Milking (DIM); 61–120 DIM; 121–180 DIM), for a total amount of 1512 samples. Bacteriological analyses and somatic cells counts (SCC) were used to define the health status of the glands. With negative bacteriological analyses and SCC 1,000,000 cells/mL, glands were classified as NH. For each milk EC signal, acquired on-line and for each gland considered, the Fourier frequency spectrum of the signal was calculated and three representative frequency peaks were identified. To evaluate data acquired a MIXED procedure was used considering the HS, LS and LS × HS as explanatory variables in the statistical model.Results showed that the studied frequency peaks had a significant relationship with the gland’s health status. Results also explained how the milk EC signals’ pattern change in case of NH glands. In fact, it is characterized by slower fluctuations (due to the lower frequencies of the peaks) and by an irregular trend (due to the higher amplitudes of all the main frequency peaks). Therefore, these frequency peaks could be used as new indexes to improve the performances of algorithms based on multivariate models which evaluate the health status of dairy goats through the use of gland milk EC sensors. PMID:26307993

  5. Achieving Efficient Spectrum Usage in Passive and Active Sensing

    Science.gov (United States)

    Wang, Huaiyi

    Increasing demand for supporting more wireless services with higher performance and reliability within the frequency bands that are most conducive to operating cost-effective cellular and mobile broadband is aggravating current electromagnetic spectrum congestion. This situation motivates technology and management innovation to increase the efficiency of spectral use. If primary-secondary spectrum sharing can be shown possible without compromising (or while even improving) performance in an existing application, opportunities for efficiency may be realizable by making the freed spectrum available for commercial use. While both active and passive sensing systems are vitally important for many public good applications, opportunities for increasing the efficiency of spectrum use can be shown to exist for both systems. This dissertation explores methods and technologies for remote sensing systems that enhance spectral efficiency and enable dynamic spectrum access both within and outside traditionally allocated bands.

  6. Recent advances in the use of acoustics across the frequency spectrum in the oil and gas industry

    Science.gov (United States)

    Zeroug, Smaine; Bose, Sandip

    2018-04-01

    Acoustics enjoys a wide array of applicability in the Oil and Gas industry. Signals with very low-frequencies (tens of Hertz) are routinely used on surface to image the earth subsurface delineating hydrocarbon reservoirs while signals with mid-frequencies (thousands of Hertz) to high-frequencies (hundreds of kilo Hertz) are used in deep boreholes to probe rock mechanical properties and evaluate completion hardware. This article reviews a few recent advances in these applications spanning both measurement concepts and processing and inversion approaches. Three applications are covered, going from high to low frequencies. The first relates to an ultrasonic imager deployed in open boreholes to probe the laminated structure of unconventional shale rock formations at depth of more than 3000 m. The imager yields rock compressional and shear wavespeed images as a function of depth and azimuth revealing a host of geomechanical manifestations of the borehole shape and near-wellbore region at an unprecedented centimetric spatial resolution. The quantitative images have bearing on rock strength and local stresses as they relate to the hydraulic fracturing of these shale formations. The second relates to the interpretation of the complex sonic response in a well cased with double steel strings cemented to the rock formation for the purpose of evaluating the integrity of the cement placed between the outer string and formation. Here, machine learning-based approaches are employed with training on modeling and experimental datasets to develop effective and wellsite diagnosis for the condition of the cement sheath. The third relates to the seismic imaging domain and the deployment of novel accelerometers added to hydrophones on marine seismic cables to capture the subsurface-reflected pressure signals and their spatial gradients. The combination of the two sensors provides the means to deghost the signal from the sea surface reflection, and more importantly, reconstruct the

  7. Dynamic event Tress applied to sequences Full Spectrum LOCA. Calculating the frequency of excedeence of damage by integrated Safety Analysis Methodology

    International Nuclear Information System (INIS)

    Gomez-Magan, J. J.; Fernandez, I.; Gil, J.; Marrao, H.; Queral, C.; Gonzalez-Cadelo, J.; Montero-Mayorga, J.; Rivas, J.; Ibane-Llano, C.; Izquierdo, J. M.; Sanchez-Perea, M.; Melendez, E.; Hortal, J.

    2013-01-01

    The Integrated Safety Analysis (ISA) methodology, developed by the Spanish Nuclear Safety council (CSN), has been applied to obtain the dynamic Event Trees (DETs) for full spectrum Loss of Coolant Accidents (LOCAs) of a Westinghouse 3-loop PWR plant. The purpose of this ISA application is to obtain the Damage Excedence Frequency (DEF) for the LOCA Event Tree by taking into account the uncertainties in the break area and the operator actuation time needed to cool down and de pressurize reactor coolant system by means of steam generator. Simulations are performed with SCAIS, a software tool which includes a dynamic coupling with MAAP thermal hydraulic code. The results show the capability of the ISA methodology to obtain the DEF taking into account the time uncertainty in human actions. (Author)

  8. Frequency of Extended-Spectrum Beta-lactamases (ESBLs) in strains of Klebsiella and E. coli isolated from patients hospitalized in Yazd.

    Science.gov (United States)

    Zandi, Hengameh; Tabatabaei, Seyed Mostafa; Ehsani, Fatemeh; Zarch, Mojtaba Babaei; Doosthosseini, Samira

    2017-02-01

    Frequency of extended-spectrum beta-lactamases (ESBLs) and its variants may vary in different geographical areas, as reports indicate their spread in some certain communities. The aim of this study was to determine the frequency of ESBLs in strains of Klebsiella and E. coli , isolated from patients hospitalized in teaching hospitals of Yazd. This cross-sectional study was carried out on samples including E. coli and Klebsiella strains collected from laboratories of Shahid Sadoughi and Shahid Rahnemoun hospitals in Yazd, Iran in the period of 2011-2012. The colonies which were positive in lactose Eosin methylene-blue (EMB) medium were identified by biochemical methods, and 270 strains of Klebsiella and E. coli were isolated. Collected data and information were analyzed using Fisher's exact test and descriptive statistics such as mean in SPSS software, version 15, at a significant level of 0.05. In this study, 270 samples were examined, including 152 samples of E. coli (56.3%) and 118 samples of Klebsiella pneumonia (43.7%). Among the 152 samples of E. coli , 45 strains (30%) were producers of ESBLs. In addition, among the 118 samples of Klebsiella pneumonia , 44 strains (37.3%) were producers of ESBLs. E. coli strains showed the most resistance to Cefotaxime (100%), Ceftazidime (97.7%), and Cefepime (75.5%) respectively and Klebsiella strains showed the most resistance to Cefotaxime (100%), Ceftazidime (100%) and Cefepime (79.5%), respectively. Frequency of ESBLs in Klebsiella strains was higher than E. coli strains. No significant relationship was found between frequency of ESBLs and age or gender. In addition, E. coli strains showed the highest sensitivity to Imipenem, Amoxicillin/clavulanate, and Ciprofloxacin, while the highest antibiotic sensitivity of Klebsiella strains was shown to be to Piperacillin, Imipenem, and Amoxicillin/clavulanate.

  9. Effects of four kinds of electromagnetic fields (EMF) with different frequency spectrum bands on ovariectomized osteoporosis in mice.

    Science.gov (United States)

    Lei, Tao; Li, Feijiang; Liang, Zhuowen; Tang, Chi; Xie, Kangning; Wang, Pan; Dong, Xu; Shan, Shuai; Liu, Juan; Xu, Qiaoling; Luo, Erping; Shen, Guanghao

    2017-04-03

    Electromagnetic fields (EMF) was considered as a non-invasive modality for treatment of osteoporosis while the effects were diverse with EMF parameters in time domain. In present study, we extended analysis of EMF characteristics from time domain to frequency domain, aiming to investigate effects of four kinds of EMF (LP (1-100 Hz), BP (100-3,000 Hz), HP (3,000-50,000 Hz) and AP (1-50,000 Hz)) on ovariectomized (OVX) osteoporosis (OP) in mice. Forty-eight 3-month-old female BALB/c mice were equally assigned to Sham, OVX, OVX + LP, OVX + BP, OVX + HP and OVX + AP groups (n = 8). After 8-week exposure (3 h/day), LP and BP significantly increased serum bone formation markers and osteogenesis-related gene expressions compared with OVX. Bedsides, LP and BP also slightly increased bone resorption activity compared with OVX, evidenced by increased RANKL/OPG ratio. HP sharply decreased serum bone formation and resporption markers and osteogenesis and osteoclastogenesis related gene expressions compared with OVX. AP had accumulative effects of LP, BP and HP, which significantly increased bone formation and decreased bone resporption activity compared with OVX. As a result, LP, BP and HP exposure did not later deterioration of bone mass, microarchitecture and mechanical strength in OVX mice with OP. However, AP stimulation attenuated OVX-induced bone loss.

  10. Study of a new technique for measuring the travel time of ultrasonic waves using the frequency spectrum

    International Nuclear Information System (INIS)

    Santos, Allan Xavier dos

    2010-01-01

    During the operation of a nuclear plant and other industrial plants, the operational time and the exposition to severe working conditions may cause the wear of its components, consequently, compromising the safety and the performance of the installation. The implementation of periodical inspections helps to ensure the safe operation and the best performance of the plant. In this way, the use of ultrasonic techniques for inspection and materials characterization becomes more and more attractive, since they offer quick, precise results and are technically ease to implement. The usual ultrasonic techniques, need to the measure the travelling time of the ultrasonic wave in the material examined in order to extract information useful to characterize it. Thus, the measurement of the travelling time of the ultrasonic wave is the overriding factor in most of the applications made with ultrasound. In this work a new technique was developed for measuring the travelling time of the ultrasonic wave using a Fourier's Fast Transformer (FFT). It will be shown mathematically and experimentally that it is possible to use the ultrasonic signal in the frequency domain to determine the travelling time of the ultrasonic wave. Five experiments were carried out for the experimental validation of this new technique. The materials used were 20 ceramic pastilles with different porosities and 3 aluminum plates of different thicknesses. The obtained results have shown that the new technique proposed in this work was able to determine the travelling time of the ultrasonic wave with the same precision as the conventional technique. It was shown, furthermore, that this new technique is able to measure the travelling time of the ultrasonic wave in situations where the conventional technique cannot be applied greatly expanding the range of application of ultrasonic testing and inspections. (author)

  11. Frequency Arrangement For 700 MHz Band

    Directory of Open Access Journals (Sweden)

    Ancans G.

    2015-02-01

    Full Text Available The 694-790 MHz (700 MHz band was allocated by the 2012 World Radiocommunication Conference (WRC-12 in ITU Region 1 (Europe included, to the mobile service on a co-primary basis with other services to which this band was allocated on the primary basis and identified for the International Mobile Telecommunications (IMT. At the same time, the countries of Region 1 will be able also to continue using these frequencies for their broadcasting services if necessary. This allocation will be effective immediately after 2015 World Radiocommunication Conference (WRC-15. In order to make the best possible use of this frequency band for mobile service, a worldwide harmonized frequency arrangement is to be prepared to allow for large economies of scale and international roaming as well as utilizing the available spectrum in the best possible way, minimizing possible interference between services, facilitating deployment and cross-border coordination. The authors analyze different possible frequency arrangements and conclude on the frequency arrangement most suitable for Europe.

  12. Hybrid spread spectrum radio system

    Science.gov (United States)

    Smith, Stephen F [London, TN; Dress, William B [Camas, WA

    2010-02-09

    Systems and methods are described for hybrid spread spectrum radio systems. A method, includes receiving a hybrid spread spectrum signal including: fast frequency hopping demodulating and direct sequence demodulating a direct sequence spread spectrum signal, wherein multiple frequency hops occur within a single data-bit time and each bit is represented by chip transmissions at multiple frequencies.

  13. Estimation of local spectrum content of cervical cancer-related features via two dimensional method of geometric restriction in frequency domain

    International Nuclear Information System (INIS)

    Van Raad, V.

    2004-01-01

    Digital colposcopy is an emerging new technology, which can be used as adjunct to the conventional Pap test for staging of cervical cancer and it can improve the diagnostic accuracy of the test. Computer aided diagnosis (CAD) in digital colposcopy has as a goal to segment and outline abnormal areas on the cervix, one of which is an important anatomical landmark on the ectocervix - the transformation zone (TZ). In this paper we proposed a new method for estimation of the local spectrum features of cervical cancer in vivo. We used a 2D method to estimate the energy of the local frequency bands, using a geometric restriction (GR). In the current work we reported up to 12 dB difference between the local power spectral density content of the region of interest (ROI) and (ROI) C for the mid-frequency band. We devised a method to present pseudo-color visual maps of the cervical images, useful for CAD and successful ROI segmentation. (author)

  14. The JET Alfven Eigenmode Local Manager for the real-time detection and tracking of a frequency-degenerate spectrum of MHD instabilities

    International Nuclear Information System (INIS)

    Testa, D.; Carfantan, H.; Fasoli, A.; Goodyear, A.; King, Q.; Blanchard, P.; Klein, A.; Lavanchy, P.; Panis, T.

    2011-01-01

    We present the real-time VME system used to detect and track MHD instabilities, and particularly Alfven Eigenmodes, on the JET tokamak [J. Wesson, Tokamaks, 3rd ed., Oxford Science Publication, Oxford, 2003, p. 617]. This system runs on a 1 kHz clock cycle, and allows performing a real-time, unsupervised and blind detection, decomposition and tracking of the individual components in a frequency-degenerate, multi-harmonic spectrum, using a small number of input data which are unevenly sampled in the spatial domain. This makes it possible to follow in real-time the detected modes as the plasma background evolves, and measure in real-time their frequency, damping rate, toroidal mode-number and relative amplitude. The successful implementation of this system opens a clear path towards developing real-time control tools for electro-magnetic instabilities in future fusion devices aimed at achieving a net energy gain, such as ITER [J. Wesson, Tokamaks, 3rd ed., Oxford Science Publication, Oxford, 2003, p. 711].

  15. Spectrum estimation method based on marginal spectrum

    International Nuclear Information System (INIS)

    Cai Jianhua; Hu Weiwen; Wang Xianchun

    2011-01-01

    FFT method can not meet the basic requirements of power spectrum for non-stationary signal and short signal. A new spectrum estimation method based on marginal spectrum from Hilbert-Huang transform (HHT) was proposed. The procession of obtaining marginal spectrum in HHT method was given and the linear property of marginal spectrum was demonstrated. Compared with the FFT method, the physical meaning and the frequency resolution of marginal spectrum were further analyzed. Then the Hilbert spectrum estimation algorithm was discussed in detail, and the simulation results were given at last. The theory and simulation shows that under the condition of short data signal and non-stationary signal, the frequency resolution and estimation precision of HHT method is better than that of FFT method. (authors)

  16. Location-Based Resource Allocation for OFDMA Cognitive Radio Systems

    KAUST Repository

    Ghorbel, Mahdi

    2011-05-01

    Cognitive radio is one of the hot topics for emerging and future wireless communication. It has been proposed as a suitable solution for the spectrum scarcity caused by the increase in frequency demand. The concept is based on allowing unlicensed users, called cognitive or secondary users, to share the unoccupied frequency bands with their owners, called the primary users, under constraints on the interference they cause to them. In order to estimate this interference, the cognitive system usually uses the channel state information to the primary user, which is often impractical to obtain. However, we propose to use location information, which is easier to obtain, to estimate this interference. The purpose of this work is to propose a subchannel and power allocation method which maximizes the secondary users\\' total capacity under the constraints of limited budget power and total interference to the primary under certain threshold. We model the problem as a constrained optimization problem for both downlink and uplink cases. Then, we propose low-complexity resource allocation schemes based on the waterfilling algorithm. The simulation results show the efficiency of the proposed method with comparison to the exhaustive search algorithm.

  17. Frequency Spectrum of Liquids and Cold Neutron Scattering; Spectre de frequences des liquides et diffusion de neutrons froids; Chastotnyj spektr zhidkostej i rasseyanie kholodnykh nejtronov; Espectro de frecuencias de los liquidos y dispersion de neutrones frios

    Energy Technology Data Exchange (ETDEWEB)

    Singwi, K S; Sjolander, A; Rahman, A [Argonne National Laboratory, Argonne, IL (United States)

    1963-01-15

    An important question which arises in connection with slow neutron scattering by liquids is: does there exist a frequency spectrum tor liquids analogous to that in solids? The answer to this question is given by showing that the width function {gamma}(t) of the Gaussian space-time self-correlation function G{sub s}(r,t) can be expressed, by using the frequency spectrum of the velocity auto-correlation function, in a form which is formally identical with that of a harmonic solid. Thus a knowledge of the frequency spectrum of the velocity auto-correlation function should enable one to calculate slow neutron scattering by liquids as has been emphasized by Egelstaff and co-workers. Using a stochastic model of a liquid, the frequency spectrum f({omega}) of the velocity auto-correlation function is calculated for water at 300{sup o}K and for liquid lead at 620{sup o}K. In the case of water a maximum in f({omega}) corresponding to {Dirac_h} 75{sup o}K is predicted. For lead the maximum also occurs at nearly the same {omega}-value. There also occurs a minimum in f({omega})in both cases. Larsson and Dahlborg have observed a maximum in f({omega}) at the above predicted {omega}-value. A recent observation in liquid lead of Cotter et al. probably confirms our prediction too. (author) [French] Dans le domaine de la diffusion des neutrons lents par des liquides une question importante se pose: existe-t-il un spectre de frequences pour les liquides analogue au spectre pour les solides? On peut repondre d cette quesnon en montrant que la fonction de largeur {gamma}(t) de la fonction gaussienne spatio-temporelle d'auto-correlation G{sub s}(r,t) peut etre exprimee, en employant le spectre de frequences de la fonction d'auto-correlation des vitesses, sous uune forme qui presente le membe aspect formel que celle d'un solide harmonique. par consequent, la connaissance du spectre de frequences de la fonction d'auto-correlation des vitesses devrait permettre de calculer la diffusion des

  18. Hemodynamic changes induced by preventive exposure to terahertz radiation at a frequency range corresponding to molecular emission and absorption spectrum of nitric oxide in animals under conditions of acute stress.

    Science.gov (United States)

    Kirichuck, V F; Velikanova, T S; Ivanov, A N

    2011-06-01

    We studied the influence of preventive irradiation with terahertz electromagnetic waves at frequencies corresponding to nitric oxide emission and absorption molecular spectrum (150,176-150,664 GHz) on hemodynamic parameters in arteries of albino rats upon acute immobilization stress. We showed that exposure to the specified frequencies can produce adaptogenic effect manifesting in the absence of post-stress changes in the linear, systolic, and diastolic blood flow velocities and pressure gradient in various blood vessels of experimental animals.

  19. Local, systemic, demographic, and health-related factors influencing pathogenic yeast spectrum and antifungal drug administration frequency in oral candidiasis: a retrospective study.

    Science.gov (United States)

    Hertel, Moritz; Schmidt-Westhausen, Andrea Maria; Strietzel, Frank-Peter

    2016-09-01

    In order to identify oral candidiasis patients being at risk of carrying potentially drug-resistant Candida, the aim of the study was to detect local, systemic, demographic, and health-related factors influencing (I) yeast spectrum composition and (II) antifungal administration frequency. Additionally, the aim was to investigate (III) species shift occurrence. Data from 798 patients (496 females, 302 males; mean age 59.7) with oral candidiasis diagnosed based on positive clinical and microbial findings (species identification and CFU count) between 2006 and 2011 were retrospectively analyzed using Pearson's chi(2) test and regression analysis. Among 958 isolates, Candida albicans was the most frequently detected (76.8 %). Also, species intrinsically resistant to azoles were frequently isolated (15.8 and 17.7 % of isolates and patients). (I) Infections only caused by C. albicans were significantly associated with the use of inhalation steroids (p = 0.001) and antibiotics (p = 0.04), super-infection of lichen planus (p = 0.002), and the absence of removable dentures (p oral candidiasis remains C. albicans. Nevertheless, therapeutic problems may be caused by the frequent presence of species intrinsically resistant to azoles, especially in patients wearing dentures.

  20. Frequency of extended spectrum β-lactamase producing urinary isolates of Gram-negative bacilli among patients seen in a multispecialty hospital in Vellore district, India

    Directory of Open Access Journals (Sweden)

    B Nandagopal

    2015-01-01

    Full Text Available Extended-spectrum beta-lactamase (ESBL producing strains of Coliform bacilli are on the rise and present a major threat especially in India. We assessed the frequency of ESBL producers among urinary isolates from patients presenting urinary tract infections. ESBL screening was done using Double Disk Synergy Test (DDST and confirmed using E-test and Polymerase Chain Reaction (PCR. With E-test, 92.2% were positive for ESBL. In PCR, 100% strains were positive for any of the three gene targets tested. CTX-M was positive in majority of the strains followed by TEM and SHV. Two (3.22% strains were positive for all the three genes; 21% strains were positive for both TEM and CTX-M genes. There was no statistically significant difference in the findings of E-test and PCR testing in the determination of ESBL producers (Fisher exact test P = 0.15. The strength of agreement between them was ′fair′ (k = 0.252. Continuous monitoring of ESBL producers among Indian strains is important to rationalize the antibiotic policy to be followed.

  1. Risk capital allocation

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Smilgins, Aleksandrs

    Risk capital allocation problems have been widely discussed in the academic literature. We consider a company with multiple subunits having individual portfolios. Hence, when portfolios of subunits are merged, a diversification benefit arises: the risk of the company as a whole is smaller than...... the sum of the risks of the individual sub-units. The question is how to allocate the risk capital of the company among the subunits in a fair way. In this paper we propose to use the Lorenz set as an allocation method. We show that the Lorenz set is operational and coherent. Moreover, we propose a set...... of new axioms related directly to the problem of risk capital allocation and show that the Lorenz set satisfies these new axioms in contrast to other well-known coherent methods. Finally, we discuss how to deal with non-uniqueness of the Lorenz set....

  2. CPD Allocations and Awards

    Data.gov (United States)

    Department of Housing and Urban Development — The CPD Allocation and Award database provides filterable on-screen and exportable reports on select programs, such as the Community Development Block Grant Program,...

  3. Features of the non-collinear one-phonon anomalous light scattering controlled by elastic waves with elevated linear losses: potentials for multi-frequency parallel spectrum analysis of radio-wave signals.

    Science.gov (United States)

    Shcherbakov, Alexandre S; Arellanes, Adan Omar

    2017-12-01

    During subsequent development of the recently proposed multi-frequency parallel spectrometer for precise spectrum analysis of wideband radio-wave signals, we study potentials of new acousto-optical cells exploiting selected crystalline materials at the limits of their capabilities. Characterizing these wide-aperture cells is non-trivial due to new features inherent in the chosen regime of an advanced non-collinear one-phonon anomalous light scattering by elastic waves with significantly elevated acoustic losses. These features can be observed simpler in uniaxial, tetragonal, and trigonal crystals possessing linear acoustic attenuation. We demonstrate that formerly studied additional degree of freedom, revealed initially for multi-phonon regimes of acousto-optical interaction, can be identified within the one-phonon geometry as well and exploited for designing new cells. We clarify the role of varying the central acoustic frequency and acoustic attenuation using the identified degree of freedom. Therewith, we are strongly restricted by a linear regime of acousto-optical interaction to avoid the origin of multi-phonon processes within carrying out a multi-frequency parallel spectrum analysis of radio-wave signals. Proof-of-principle experiments confirm the developed approaches and illustrate their applicability to innovative technique for an advanced spectrum analysis of wideband radio-wave signals with the improved resolution in an extended frequency range.

  4. Coping with Radio Frequency Interference

    Science.gov (United States)

    Lewis, B. M.

    2009-01-01

    The radio spectrum is a finite resource, on which humanity makes many demands. And pressure on it is ever increasing with the development of new technology and ideas for radio services. After all, we all benefit from wifi and cell phones. Radio astronomers have a small percentage of the spectrum allocated to them at octave intervals in the metre-centimetre bands, and at important frequencies, such as that of the 21cm line of HI. Signals from other services, as well as from our own poorly-engineered equipment, sometimes contaminate our bands: these signals constitute RFI. These may totally obliterate the astronomical signal, or, in the case of CLOUDSAT, may be capable of completely destroying a receiver, which introduces us to the new possibility of 'destructive interference'. A geo-stationary satellite can block access to a piece of sky from one site. Good equipment design eliminates self-inflicted interference, while physical separation often provides adequate practical mitigation at many frequencies. However, new observatories end up being located in the West Australian desert or Antarctica. In future they may be on the back side of the Moon. But there is no Earth-bound protection via physical separation against satellite signals. Some mitigation can be achieved by frequent data dumps and the excision of RFI, or by real-time detection and blanking of the receiver, or by more sophisticated algoriths. Astronomers of necessity aim to achieve mitigation via coordination, at the local level, and by participating in spectrum management at the national and international levels. This involves them spending a lot of time in Geneva at the International Telegraphic Union protecting their access to spectrum, and access to clean spectrum from the L3 point and the far side of the Moon.

  5. Multi-Layer Soft Frequency Reuse Scheme for 5G Heterogeneous Cellular Networks

    DEFF Research Database (Denmark)

    Shakir, Md. Hossain; Tariq, Faisal; Safdar, Ghazanfar

    2017-01-01

    Heterogeneous network (HetNet) is a promising cell deployment technique where low power access points are deployed overlaid on a macrocell system. It attains high throughput by intelligently reusing spectrum, and brings a trade-off between energy- and spectral-efficiency. An efficient resource...... allocation strategy is required to significantly improve its throughput in a bid to meet the fifth-generation (5G) high data rate requirements. In this correspondence, a new resource allocation scheme for HetNet, called multi-level soft frequency reuse for HetNet (ML-SFR HetNet), is proposed which increases...... the throughput several fold. We derived spectrum and power allocation expression for a generalized HetNet scenario. In addition, analytical expressions for the throughput and area spectral efficiency (ASE) are also developed. The simulations results demonstrates the efficiency of the proposed scheme which...

  6. Computationally Efficient Power Allocation Algorithm in Multicarrier-Based Cognitive Radio Networks: OFDM and FBMC Systems

    Directory of Open Access Journals (Sweden)

    Shaat Musbah

    2010-01-01

    Full Text Available Cognitive Radio (CR systems have been proposed to increase the spectrum utilization by opportunistically access the unused spectrum. Multicarrier communication systems are promising candidates for CR systems. Due to its high spectral efficiency, filter bank multicarrier (FBMC can be considered as an alternative to conventional orthogonal frequency division multiplexing (OFDM for transmission over the CR networks. This paper addresses the problem of resource allocation in multicarrier-based CR networks. The objective is to maximize the downlink capacity of the network under both total power and interference introduced to the primary users (PUs constraints. The optimal solution has high computational complexity which makes it unsuitable for practical applications and hence a low complexity suboptimal solution is proposed. The proposed algorithm utilizes the spectrum holes in PUs bands as well as active PU bands. The performance of the proposed algorithm is investigated for OFDM and FBMC based CR systems. Simulation results illustrate that the proposed resource allocation algorithm with low computational complexity achieves near optimal performance and proves the efficiency of using FBMC in CR context.

  7. IMPROVED DETERMINATION OF THE 1{sub 0}-0{sub 0} ROTATIONAL FREQUENCY OF NH{sub 3}D{sup +} FROM THE HIGH-RESOLUTION SPECTRUM OF THE {nu}{sub 4} INFRARED BAND

    Energy Technology Data Exchange (ETDEWEB)

    Domenech, J. L.; Cueto, M.; Herrero, V. J.; Tanarro, I. [Molecular Physics Department, Instituto de Estructura de la Materia (IEM-CSIC), Serrano 123, E-28006 Madrid (Spain); Tercero, B.; Cernicharo, J. [Department of Astrophysics, CAB, INTA-CSIC, Crta Torrejon-Ajalvir Km 4, E-28850 Torrejon de Ardoz, Madrid (Spain); Fuente, A., E-mail: jl.domenech@csic.es [Observatorio Astronomico Nacional, Apdo. 112, E-28803 Alcala de Henares (Spain)

    2013-07-01

    The high-resolution spectrum of the {nu}{sub 4} band of NH{sub 3}D{sup +} has been measured by difference frequency IR laser spectroscopy in a multipass hollow cathode discharge cell. From the set of molecular constants obtained from the analysis of the spectrum, a value of 262817 {+-} 6 MHz ({+-}3{sigma}) has been derived for the frequency of the 1{sub 0}-0{sub 0} rotational transition. This value supports the assignment to NH{sub 3}D{sup +} of lines at 262816.7 MHz recorded in radio astronomy observations in Orion-IRc2 and the cold prestellar core B1-bS.

  8. Allocating multiple units

    DEFF Research Database (Denmark)

    Tranæs, Torben; Krishna, Kala

    2002-01-01

    This paper studies the allocation and rent distribution in multi-unit, combinatorial-bid auctions under complete information. We focus on the natural multi-unit analogue of the first-price auction, where buyers bid total payments, pay their bids, and where the seller allocates goods to maximize his...... auction, which is the multi unit analogue of a second-price auction. Furthermore, we characterize these equilibria when valuations take a number of different forms: diminishing marginal valuations, increasing average valuations, and marginal valuations with single turning points...

  9. The Economic Importance of Adequate Aeronautical Telemetry Spectrum

    National Research Council Canada - National Science Library

    Kahn, Carolyn A

    2005-01-01

    INTRODUCTION: (1) The flight test community faces a telemetry spectrum crunch; (2) Amount of spectrum now allocated for ATM is not sufficient to meet needs, and requirements have been steadily growing...

  10. The Spectrum Landscape: Prospects for Terrestrial Radio Astronomy

    Science.gov (United States)

    Liszt, Harvey Steven

    2018-01-01

    Radio astronomers work within broad constraints imposed by commercial and other non-astronomical uses of the radio spectrum, somewhat modified to accommodate astronomy’s particular needs through the provision of radio quiet zones, radio frequency allocations, coordination agreements and other devices of spectrum management. As radio astronomers increase the instantaneous bandwidth, frequency coverage and sensitivity of their instruments, these external constraints, and not the limitations of their own instruments, will increasingly be the greatest obstacles to radio astronomy’s ability to observe the cosmos from the surface of the Earth. Therefore, prospects for future radio astronomy operations are contingent on situational awareness and planning for the impact of non-astronomical uses of the radio frequency spectrum. New radio astronomy instruments will have to incorporate adaptive reactions to external developments, and radio astronomers should be encouraged to think in untraditional ways. Increased attention to spectrum management is one of these. In this talk I’ll recap some recent developments such as the proliferation of 76 – 81 GHz car radar and orbiting earth-mapping radars, either of which can burn out a radio astronomy receiver. I’ll summarize present trends for non-astronomical radio spectrum use that will be coming to fruition in the next decade or so, categorized into terrestrial fixed and mobile, airborne and space-borne uses, sub-divided by waveband from the cm to the sub-mm. I’ll discuss how they will impact terrestrial radio astronomy and the various ways in which radio astronomy should be prepared to react. Protective developments must occur both within radio astronomy’s own domain – designing, siting and constructing its instruments and mitigating unavoidable RFI – and facing outward toward the community of other spectrum users. Engagement with spectrum management is no panacea but it is an important means, and perhaps the only

  11. Far-infrared cw difference-frequency generation using vertically integrated and planar low temperature grown GaAs photomixers: application to H2S rotational spectrum up to 3 THz

    Science.gov (United States)

    Mouret, G.; Matton, S.; Bocquet, R.; Hindle, F.; Peytavit, E.; Lampin, J. F.; Lippens, D.

    2004-10-01

    The generation of continuous coherent THz radiation by mixing two cw Ti:Sa laser beams with a well-controlled frequency separation for a new scheme of vertically integrated low temperature grown GaAs (LTG-GaAs) spiral photomixer is reported. For this new photomixer device used in THz emission, the LTG-GaAs active layer is sandwiched between the two parallel metal plates of a high-speed photodetector loaded by a broadband spiral antenna. We have exploited the advantage of a higher delivered power in the low part of the spectrum (<2000 GHz), while a low RC time constant planar interdigitated detector was used at the upper frequency. The performances of the spectroscopic setup in terms of spectral resolution (5 MHz), tunability and frequency capability are assessed by measurements of the pure rotational spectra of hydrogen sulfide (H2S) up to 3000 GHz.

  12. Estimation of Distribution Algorithm for Resource Allocation in Green Cooperative Cognitive Radio Sensor Networks

    Directory of Open Access Journals (Sweden)

    Alagan Anpalagan

    2013-04-01

    Full Text Available Due to the rapid increase in the usage and demand of wireless sensor networks (WSN, the limited frequency spectrum available for WSN applications will be extremely crowded in the near future. More sensor devices also mean more recharging/replacement of batteries, which will cause significant impact on the global carbon footprint. In this paper, we propose a relay-assisted cognitive radio sensor network (CRSN that allocates communication resources in an environmentally friendly manner. We use shared band amplify and forward relaying for cooperative communication in the proposed CRSN. We present a multi-objective optimization architecture for resource allocation in a green cooperative cognitive radio sensor network (GC-CRSN. The proposed multi-objective framework jointly performs relay assignment and power allocation in GC-CRSN, while optimizing two conflicting objectives. The first objective is to maximize the total throughput, and the second objective is to minimize the total transmission power of CRSN. The proposed relay assignment and power allocation problem is a non-convex mixed-integer non-linear optimization problem (NC-MINLP, which is generally non-deterministic polynomial-time (NP-hard. We introduce a hybrid heuristic algorithm for this problem. The hybrid heuristic includes an estimation-of-distribution algorithm (EDA for performing power allocation and iterative greedy schemes for constraint satisfaction and relay assignment. We analyze the throughput and power consumption tradeoff in GC-CRSN. A detailed analysis of the performance of the proposed algorithm is presented with the simulation results.

  13. SPECTRUM AGGREGATION WITH OPTIMAL MULTI-BAND SCHEDULING

    DEFF Research Database (Denmark)

    Mihovska, Albena D.

    2010-01-01

    This paper seeks to explore the integration of spectrum and network resource management functionalities to the benefit of achieving higher performance and capacity gains in an International Mobile Telecommunications-Advanced (IMT-A) scenario. In particular, we investigate the allocation of users...... over two frequency bands (i.e., 2 GHz and 5 GHz) for a single operator scenario. The same type of Radio Access Technology (RAT) is considered for both frequency bands. It is assumed that the operator has gained access to a non-shared 2 GHz band and to part (or all) of the frequency pool band at 5 GHz....... The performance gain is analyzed in terms of higher data throughput. The performance is heavily dependent on the channel quality for each user in the considered bands which, in turn, is a function of the path loss and the distance from the Base Station (BS). The operator will have relevant improvements when...

  14. Applied cost allocation

    DEFF Research Database (Denmark)

    Bogetoft, Peter; Hougaard, Jens Leth; Smilgins, Aleksandrs

    2016-01-01

    This paper deals with empirical computation of Aumann–Shapley cost shares for joint production. We show that if one uses a mathematical programing approach with its non-parametric estimation of the cost function there may be observations in the data set for which we have multiple Aumann–Shapley p...... of assumptions concerning firm behavior. These assumptions enable us to connect inefficient with efficient production and thereby provide consistent ways of allocating the costs arising from inefficiency....

  15. Variety Is Not the Spice of Life for People with Autism Spectrum Disorders: Frequency Ratings of Central, Variable and Inappropriate Aspects of Common Real-Life Events

    Science.gov (United States)

    Loth, Eva; Happe, Francesca; Gomez, Juan Carlos

    2010-01-01

    This study used a novel rating task to investigate whether high-functioning individuals with autism spectrum disorder (ASD) have difficulties distinguishing essential from variable aspects of familiar events. Participants read stories about everyday events and judged how often central, variable, and inappropriate event-components normally occur in…

  16. Frequency noise in frequency swept fiber laser

    DEFF Research Database (Denmark)

    Pedersen, Anders Tegtmeier; Rottwitt, Karsten

    2013-01-01

    This Letter presents a measurement of the spectral content of frequency shifted pulses generated by a lightwave synthesized frequency sweeper. We found that each pulse is shifted in frequency with very high accuracy. We also discovered that noise originating from light leaking through the acousto......- optical modulators and forward propagating Brillouin scattering appear in the spectrum. © 2013 Optical Society of America....

  17. Astronomers Win Protection for Key Part of Radio Spectrum

    Science.gov (United States)

    2000-06-01

    Astronomers using the millimeter-wave region of the radio spectrum have won crucial protection for their science. Dedicated allocations for radio astronomy have been given final approval by the 2,500 delegates to the World Radiocommunication Conference (WRC-00), which recently concluded a month of deliberations in Istanbul, Turkey. Radio services can transmit in these parts of the spectrum as long as they don't hinder astronomers' attempts to catch faint signals from the cosmos. The new allocations represent the culmination of more than three years of cooperative planning by radio astronomers in many countries. Millimeter waves -- high-frequency radio waves -- have come of age as an astronomical tool in the last ten years. They are one of the last technological frontiers for astronomers. WRC-00 has protected for science all the frequencies between 71 and 275 Gigahertz (GHz) that radio astronomers currently use, adding more than 90 GHz of spectrum to the 44 GHz already set aside in this frequency range. As a result, radio astronomy is now allocated most of the frequencies between 71 and 275 GHz that can get through the Earth's atmosphere. "We have formal access to all three atmospheric 'windows', apart from their very edges," said Dr. Tom Gergely of the National Science Foundation, one of the U.S. delegates to WRC-00. The WRC also changed most of the frequencies allocated to satellite downlinks within the 71-275 GHz range to frequencies not used for science. Since no satellites yet operate at these high frequencies, no equipment needs to be altered. "Commercial technologies are just starting to develop above 50 GHz," said Dr. Klaus Ruf, Chairman of the Inter-Union Commission for the Allocation of Frequencies. "The WRC's actions mean that, when they are, radio astronomers should be able to share this part of the spectrum with most terrestrial services." The World Radiocommunication Conference is held every two or three years. Here member countries of the

  18. Emissions allocation in transportation routes

    NARCIS (Netherlands)

    Leenders, B.P.J.; Velázquez Martínez, J.; Fransoo, J.C.

    2017-01-01

    This article studies the allocation of CO2 emissions to a specific shipment in routing transportation. The authors show that this problem differs from a cost allocation problem specifically because the concavity condition does not hold necessarily in the CO2 allocation problem. This implies that a

  19. Energy Efficient Resource Allocation for Cognitive Radios: A Generalized Sensing Analysis

    KAUST Repository

    Alabbasi, Abdulrahman

    2014-12-31

    In this paper, two resource allocation schemes for energy efficient cognitive radio systems are proposed. Our design considers resource allocation approaches that adopt spectrum sharing combined with soft-sensing information, adaptive sensing thresholds, and adaptive power to achieve an energy efficient system. An energy per good-bit metric is considered as an energy efficient objective function. A multi-carrier system, such as, orthogonal frequency division multiplexing, is considered in the framework. The proposed resource allocation schemes, using different approaches, are designated as sub-optimal and optimal. The sub-optimal approach is attained by optimizing over a channel inversion power policy. The optimal approach utilizes the calculus of variation theory to optimize a problem of instantaneous objective function subject to average and instantaneous constraints with respect to functional optimization variables. In addition to the analytical results, selected numerical results are provided to quantify the impact of soft-sensing information and the optimal adaptive sensing threshold on the system performance.

  20. Energy Efficient Resource Allocation for Cognitive Radios: A Generalized Sensing Analysis

    KAUST Repository

    Alabbasi, AbdulRahman; Rezki, Zouheir; Shihada, Basem

    2014-01-01

    In this paper, two resource allocation schemes for energy efficient cognitive radio systems are proposed. Our design considers resource allocation approaches that adopt spectrum sharing combined with soft-sensing information, adaptive sensing thresholds, and adaptive power to achieve an energy efficient system. An energy per good-bit metric is considered as an energy efficient objective function. A multi-carrier system, such as, orthogonal frequency division multiplexing, is considered in the framework. The proposed resource allocation schemes, using different approaches, are designated as sub-optimal and optimal. The sub-optimal approach is attained by optimizing over a channel inversion power policy. The optimal approach utilizes the calculus of variation theory to optimize a problem of instantaneous objective function subject to average and instantaneous constraints with respect to functional optimization variables. In addition to the analytical results, selected numerical results are provided to quantify the impact of soft-sensing information and the optimal adaptive sensing threshold on the system performance.

  1. Game-Theoretic Social-Aware Resource Allocation for Device-to-Device Communications Underlaying Cellular Network

    Directory of Open Access Journals (Sweden)

    Lei Wang

    2018-01-01

    Full Text Available Device-to-Device communication underlaying cellular network can increase the spectrum efficiency due to direct proximity communication and frequency reuse. However, such performance improvement is influenced by the power interference caused by spectrum sharing and social characteristics in each social community jointly. In this investigation, we present a dynamic game theory with complete information based D2D resource allocation scheme for D2D communication underlaying cellular network. In this resource allocation method, we quantify both the rate influence from the power interference caused by the D2D transmitter to cellular users and rate enhancement brought by the social relationships between mobile users. Then, the utility function maximization game is formulated to optimize the overall transmission rate performance of the network, which synthetically measures the final influence from both power interference and sociality enhancement. Simultaneously, we discuss the Nash Equilibrium of the proposed utility function maximization game from a theoretical point of view and further put forward a utility priority searching algorithm based resource allocation scheme. Simulation results show that our proposed scheme attains better performance compared with the other two advanced proposals.

  2. Cost allocation with limited information

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Tind, Jørgen

    This article investigates progressive development of Aumann-Shapley cost allocation in a multilevel organizational or production structure. In particular, we study a linear parametric programming setup utilizing the Dantzig-Wolfe decomposition procedure. Typically cost allocation takes place after...... all activities have been performed, for example by finishing all outputs. Here the allocation is made progressively with suggestions for activities. I other words cost allocation is performed in parallel for example with a production planning process. This development does not require detailed...... information about some technical constraints in order to make the cost allocation....

  3. Joint Resource Allocation for Dual - Band Heterogeneous Wireless Network

    DEFF Research Database (Denmark)

    Adeogun, Ramoni

    2018-01-01

    In this paper, we investigate downlink resource allocation in two-tier OFDMA heterogeneous networks comprising a macrocell transmitting at a microwave frequency and dual band small cells utilizing both microwave and millimeter wave frequencies. A non - cooperative game theoretic approach...... is proposed for adaptively switching the SC transmission frequency based on the location of small cell users and interference to macrocell users. We propose a resource allocation approach which maximizes the sum rate of small cell users while minimizing interference to macrocell users and the total power...

  4. Function allocation in distributed safeguards and security systems

    International Nuclear Information System (INIS)

    Barlich, G.L.

    1991-01-01

    Computerized distributed systems are being used to collect and manage data for activities such as nuclear materials accounting, process control, laboratory coordination, and security. Poor choices made in allocating functions to individual processors can make a system unusable by burdening machines with excessive network retrievals and updates. During system design phases, data allocation algorithms based on operation frequencies, field sizes, security information, and reliability requirements can be applied in sensitivity studies to mathematically ensure processor efficiency. The Los Alamos Network Design System (NDS) implements such an allocation algorithm. The authors analyzed a large, existing distributed system to test the cost functions and to compare actual network problems with NDS results. Several common configurations were also designed and studied using the software. From these studies, some basic principles for allocating functions emerged. In this paper recommendations for function allocation in generic systems and related design options are discussed

  5. Molecular spectrum of KRAS, NRAS, BRAF, PIK3CA, TP53, and APC somatic gene mutations in Arab patients with colorectal cancer: determination of frequency and distribution pattern

    Science.gov (United States)

    Al-Shamsi, Humaid O.; Jones, Jeremy; Fahmawi, Yazan; Dahbour, Ibrahim; Tabash, Aziz; Abdel-Wahab, Reham; Abousamra, Ahmed O. S.; Shaw, Kenna R.; Xiao, Lianchun; Hassan, Manal M.; Kipp, Benjamin R.; Kopetz, Scott; Soliman, Amr S.; McWilliams, Robert R.; Wolff, Robert A.

    2016-01-01

    Background The frequency rates of mutations such as KRAS, NRAS, BRAF, and PIK3CA in colorectal cancer (CRC) differ among populations. The aim of this study was to assess mutation frequencies in the Arab population and determine their correlations with certain clinicopathological features. Methods Arab patients from the Arab Gulf region and a population of age- and sex-matched Western patients with CRC whose tumors were evaluated with next-generation sequencing (NGS) were identified and retrospectively reviewed. The mutation rates of KRAS, NRAS, BRAF, PIK3CA, TP53, and APC were recorded, along with clinicopathological features. Other somatic mutation and their rates were also identified. Fisher’s exact test was used to determine the association between mutation status and clinical features. Results A total of 198 cases were identified; 99 Arab patients and 99 Western patients. Fifty-two point seven percent of Arab patients had stage IV disease at initial presentation, 74.2% had left-sided tumors. Eighty-nine point two percent had tubular adenocarcinoma and 10.8% had mucinous adenocarcinoma. The prevalence rates of KRAS, NRAS, BRAF, PIK3CA, TP53, APC, SMAD, FBXW7 mutations in Arab population were 44.4%, 4%, 4%, 13.1%, 52.5%, 27.3%, 2% and 3% respectively. Compared to 48.4%, 4%, 4%, 12.1%, 47.5%, 24.2%, 11.1% and 0% respectively in matched Western population. Associations between these mutations and patient clinicopathological features were not statistically significant. Conclusions This is the first study to report comprehensive hotspot mutations using NGS in Arab patients with CRC. The frequency of KRAS, NRAS, BRAF, TP53, APC and PIK3CA mutations were similar to reported frequencies in Western population except SMAD4 that had a lower frequency and higher frequency of FBXW7 mutation. PMID:28078112

  6. Quasi Path Restoration: A post-failure recovery scheme over pre-allocated backup resource for elastic optical networks

    Science.gov (United States)

    Yadav, Dharmendra Singh; Babu, Sarath; Manoj, B. S.

    2018-03-01

    Spectrum conflict during primary and backup routes assignment in elastic optical networks results in increased resource consumption as well as high Bandwidth Blocking Probability. In order to avoid such conflicts, we propose a new scheme, Quasi Path Restoration (QPR), where we divide the available spectrum into two: (1) primary spectrum (for primary routes allocation) and (2) backup spectrum (for rerouting the data on link failures). QPR exhibits three advantages over existing survivable strategies such as Shared Path Protection (SPP), Primary First Fit Backup Last Fit (PFFBLF), Jointly Releasing and re-establishment Defragmentation SPP (JRDSSPP), and Path Restoration (PR): (1) the conflict between primary and backup spectrum during route assignment is completely eliminated, (2) upon a link failure, connection recovery requires less backup resources compared to SPP, PFFBLF, and PR, and (3) availability of the same backup spectrum on each link improves the recovery guarantee. The performance of our scheme is analyzed with different primary backup spectrum partitions on varying connection-request demands and number of frequency slots. Our results show that QPR provides better connection recovery guarantee and Backup Resources Utilization (BRU) compared to bandwidth recovery of PR strategy. In addition, we compare QPR with Shared Path Protection and Primary First-Fit Backup Last Fit strategies in terms of Bandwidth Blocking Probability (BBP) and average frequency slots per connection request. Simulation results show that BBP of SPP, PFFBLF, and JRDSPP varies between 18.59% and 14.42%, while in QPR, BBP ranges from 2.55% to 17.76% for Cost239, NSFNET, and ARPANET topologies. Also, QPR provides bandwidth recovery between 93.61% and 100%, while in PR, the recovery ranges from 86.81% to 98.99%. It is evident from our analysis that QPR provides a reasonable trade-off between bandwidth blocking probability and connection recoverability.

  7. Optimal transmit power allocation for MIMO two-way cognitive relay networks with multiple relays using AF strategy

    KAUST Repository

    Alsharoa, Ahmad M.

    2014-02-01

    In this letter, we consider a multiple-input multiple-output two-way cognitive radio system under a spectrum sharing scenario, where primary and secondary users operate on the same frequency band. The secondary terminals aims to exchange different messages with each other using multiple relays where each relay employs an amplify-and-forward strategy. The main objective of our work is to maximize the secondary sum rate allowed to share the spectrum with the primary users by respecting a primary user tolerated interference threshold. In this context, we derive an analytical expression of the optimal power allocated to each antenna of the terminals. We then discuss the impact of some system parameters on the performance in the numerical result section. © 2012 IEEE.

  8. Spectrum and network measurements

    CERN Document Server

    Witte, Robert A

    2014-01-01

    This new edition of Spectrum and Network Measurements enables readers to understand the basic theory, relate it to measured results, and apply it when creating new designs. This comprehensive treatment of frequency domain measurements successfully consolidates all the pertinent theory into one text. It covers the theory and practice of spectrum and network measurements in electronic systems. It also provides thorough coverage of Fourier analysis, transmission lines, intermodulation distortion, signal-to-noise ratio and S-parameters.

  9. Study on the ternary mixed ligand complex of palladium(II)-aminophylline-fluorescein sodium by resonance Rayleigh scattering, second-order scattering and frequency doubling scattering spectrum and its analytical application.

    Science.gov (United States)

    Chen, Peili; Liu, Shaopu; Liu, Zhongfang; Hu, Xiaoli

    2011-01-01

    The interaction between palladium(II)-aminophylline and fluorescein sodium was investigated by resonance Rayleigh scattering, second-order scattering and frequency doubling scattering spectrum. In pH 4.4 Britton-Robinson (BR) buffer medium, aminophylline (Ami) reacted with palladium(II) to form chelate cation([Pd(Ami)]2+), which further reacted with fluorescein sodium (FS) to form ternary mixed ligand complex [Pd(Ami)(FS)2]. As a result, resonance Rayleigh scattering (RRS), second-order scattering (SOS) and frequency doubling scattering spectrum (FDS) were enhanced. The maximum scattering wavelengths of [Pd(Ami)(FS)2] were located at 300 nm (RRS), 650 nm (SOS) and 304 nm (FDS). The scattering intensities were proportional to the Ami concentration in a certain range and the detection limits were 7.3 ng mL(-1) (RRS), 32.9 ng mL(-1) (SOS) and 79.1 ng mL(-1) (FDS), respectively. Based on it, the new simple, rapid, and sensitive scattering methods have been proposed to determine Ami in urine and serum samples. Moreover, the formation mechanism of [Pd(Ami)(FS)2] and the reasons for enhancement of RRS were fully discussed. Crown Copyright © 2010. Published by Elsevier B.V. All rights reserved.

  10. Power frequency spectrum analysis of surface EMG signals of upper limb muscles during elbow flexion - A comparison between healthy subjects and stroke survivors.

    Science.gov (United States)

    Angelova, Silvija; Ribagin, Simeon; Raikova, Rositsa; Veneva, Ivanka

    2018-02-01

    After a stroke, motor units stop working properly and large, fast-twitch units are more frequently affected. Their impaired functions can be investigated during dynamic tasks using electromyographic (EMG) signal analysis. The aim of this paper is to investigate changes in the parameters of the power/frequency function during elbow flexion between affected, non-affected, and healthy muscles. Fifteen healthy subjects and ten stroke survivors participated in the experiments. Electromyographic data from 6 muscles of the upper limbs during elbow flexion were filtered and normalized to the amplitudes of EMG signals during maximal isometric tasks. The moments when motion started and when the flexion angle reached its maximal value were found. Equal intervals of 0.3407 s were defined between these two moments and one additional interval before the start of the flexion (first one) was supplemented. For each of these intervals the power/frequency function of EMG signals was calculated. The mean (MNF) and median frequencies (MDF), the maximal power (MPw) and the area under the power function (APw) were calculated. MNF was always higher than MDF. A significant decrease in these frequencies was found in only three post-stroke survivors. The frequencies in the first time interval were nearly always the highest among all intervals. The maximal power was nearly zero during first time interval and increased during the next ones. The largest values of MPw and APw were found for the flexor muscles and they increased for the muscles of the affected arm compared to the non-affected one of stroke survivors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Theory of stable allocations

    Directory of Open Access Journals (Sweden)

    Pantelić Svetlana

    2014-01-01

    Full Text Available The Swedish Royal Academy awarded the 2012 Nobel Prize in Economics to Lloyd Shapley and Alvin Roth, for the theory of stable allocations and the practice of market design. These two American researchers worked independently from each other, combining basic theory and empirical investigations. Through their experiments and practical design they generated a flourishing field of research and improved the performance of many markets. Born in 1923 in Cambridge, Massachusetts, Shapley defended his doctoral thesis at Princeton University in 1953. For many years he worked at RAND, and for more than thirty years he was a professor at UCLA University. He published numerous scientific papers, either by himself or in cooperation with other economists.

  12. SSC accelerator availability allocation

    International Nuclear Information System (INIS)

    Dixon, K.T.; Franciscovich, J.

    1991-03-01

    Superconducting Super Collider (SSC) operational availability is an area of major concern, judged by the Central Design Group to present such risk that use of modern engineering tools would be essential to program success. Experience has shown that as accelerator beam availability falls below about 80%, efficiency of physics experiments degrades rapidly due to inability to maintain adequate coincident accelerator and detector operation. For this reason, the SSC availability goal has been set at 80%, even though the Fermi National Accelerator Laboratory accelerator, with a fraction of the SSC's complexity, has only recently approached that level. This paper describes the allocation of the top-level goal to part-level reliability and maintainability requirements, and it gives the results of parameter sensitivity studies designed to help identify the best approach to achieve the needed system availability within funding and schedule constraints. 1 ref., 12 figs., 4 tabs

  13. Attending Globally or Locally: Incidental Learning of Optimal Visual Attention Allocation

    Science.gov (United States)

    Beck, Melissa R.; Goldstein, Rebecca R.; van Lamsweerde, Amanda E.; Ericson, Justin M.

    2018-01-01

    Attention allocation determines the information that is encoded into memory. Can participants learn to optimally allocate attention based on what types of information are most likely to change? The current study examined whether participants could incidentally learn that changes to either high spatial frequency (HSF) or low spatial frequency (LSF)…

  14. Importance measures and resource allocation

    International Nuclear Information System (INIS)

    Guey, C.N.; Morgan, T.; Hughes, E.A.

    1987-01-01

    This paper discusses various importance measures and their practical relevance to allocating resources. The characteristics of importance measures are illustrated through simple examples. Important factors associated with effectively allocating resources to improve plant system performance or to prevent system degradation are discussed. It is concluded that importance measures are only indicative of and not equal to the risk significance of a component, system, or event. A decision framework is suggested to provide a comprehensive basis for resource allocation

  15. IPO Allocations: Discriminatory or Discretionary?

    OpenAIRE

    William Wilhelm; Alexander Ljungqvist

    2001-01-01

    We estimate the structural links between IPO allocations, pre-market information production, and initial underpricing returns, within the context of theories of bookbuilding. Using a sample of both US and international IPOs we find evidence of the following: ? IPO allocation policies favour institutional investors, both in the US and worldwide. ? Increasing institutional allocations results in offer prices that deviate more from the indicative price range established prior to bankers’ efforts...

  16. Variety is not the spice of life for people with autism spectrum disorders: frequency ratings of central, variable and inappropriate aspects of common real-life events.

    Science.gov (United States)

    Loth, Eva; Happé, Francesca; Gómez, Juan Carlos

    2010-06-01

    This study used a novel rating task to investigate whether high-functioning individuals with autism spectrum disorder (ASD) have difficulties distinguishing essential from variable aspects of familiar events. Participants read stories about everyday events and judged how often central, variable, and inappropriate event-components normally occur in this type of situation. The ASD boys made significantly more errors than the typically developing boys in rating the occurrences of variable aspects. In both groups, ratings of variable aspects were age-related, but in the ASD boys, they were also related to theory of mind and weak coherence test scores, and to severity of autistic symptoms. Implications for the understanding of some repetitive behaviours, such as the tendency to adhere to inflexible routines, are discussed.

  17. Influence of induced colour centres on the frequency - angular spectrum of a light bullet of mid-IR radiation in lithium fluoride

    Science.gov (United States)

    Chekalin, S. V.; Kompanets, V. O.; Dormidonov, A. E.; Kandidov, V. P.

    2017-04-01

    The influence of the occurrence of a structure consisting of long-lived colour centres, formed in an LiF crystal upon filamentation of femtosecond mid-IR radiation, on the supercontinuum characteristics is investigated. With an increase in the number of incident pulses, the length and transverse size of the structure of colour centres induced in LiF increase, and the supercontinuum spectrum in the short-wavelength region is markedly transformed due to the occurrence of the waveguide propagation regime, absorption, and scattering of radiation from the newly formed structure of colour centres. Under these conditions, the intensity of the anti-Stokes wing decreases by two orders of magnitude after several tens of pulses. Spectral components arise in the visible range, the angular divergence of which increases with increasing wavelength.

  18. Frequency and phenotypic spectrum of germline mutations in POLE and seven other polymerase genes in 266 patients with colorectal adenomas and carcinomas.

    Science.gov (United States)

    Spier, Isabel; Holzapfel, Stefanie; Altmüller, Janine; Zhao, Bixiao; Horpaopan, Sukanya; Vogt, Stefanie; Chen, Sophia; Morak, Monika; Raeder, Susanne; Kayser, Katrin; Stienen, Dietlinde; Adam, Ronja; Nürnberg, Peter; Plotz, Guido; Holinski-Feder, Elke; Lifton, Richard P; Thiele, Holger; Hoffmann, Per; Steinke, Verena; Aretz, Stefan

    2015-07-15

    In a number of families with colorectal adenomatous polyposis or suspected Lynch syndrome/HNPCC, no germline alteration in the APC, MUTYH, or mismatch repair (MMR) genes are found. Missense mutations in the polymerase genes POLE and POLD1 have recently been identified as rare cause of multiple colorectal adenomas and carcinomas, a condition termed polymerase proofreading-associated polyposis (PPAP). The aim of the present study was to evaluate the clinical relevance and phenotypic spectrum of polymerase germline mutations. Therefore, targeted sequencing of the polymerase genes POLD1, POLD2, POLD3, POLD4, POLE, POLE2, POLE3 and POLE4 was performed in 266 unrelated patients with polyposis or fulfilled Amsterdam criteria. The POLE mutation c.1270C>G;p.Leu424Val was detected in four unrelated patients. The mutation was present in 1.5% (4/266) of all patients, 4% (3/77) of all familial cases and 7% (2/30) of familial polyposis cases. The colorectal phenotype in 14 affected individuals ranged from typical adenomatous polyposis to a HNPCC phenotype, with high intrafamilial variability. Multiple colorectal carcinomas and duodenal adenomas were common, and one case of duodenal carcinoma was reported. Additionally, various extraintestinal lesions were evident. Nine further putative pathogenic variants were identified. The most promising was c.1306C>T;p.Pro436Ser in POLE. In conclusion, a PPAP was identified in a substantial number of polyposis and familial colorectal cancer patients. Screening for polymerase proofreading mutations should therefore be considered, particularly in unexplained familial cases. The present study broadens the phenotypic spectrum of PPAP to duodenal adenomas and carcinomas, and identified novel, potentially pathogenic variants in four polymerase genes. © 2014 UICC.

  19. [Research progress of mutational spectrum and pathophysiology of WFS1 gene in Wolfram syndrome and nonsyndromic low frequency sensorineural hearing loss].

    Science.gov (United States)

    Shi, S M; Han, Y H; Wang, H B

    2016-09-07

    Compound homozygous or heterozygous mutations in WFS 1 can lead to autosomal recessive Wolfram syndrome (WS), and heterozygous mutations in WFS 1 can lead to autosomal dominant non-syndromic low frequency sensorineural hearing loss (LFSNHL). In addition, mutations in the WFS region has relationship with diabetes and psychiatric diseases. In this paper, we provide an overview of genetic research with different phenotypes, including WS and LFSNHL.

  20. Induced micro-mutations in rice - the frequency and spectrum of gamma ray induced height variations in rice variety-Jaya

    International Nuclear Information System (INIS)

    Nair, N.K.; Ninan, C.A.

    1975-01-01

    Seeds of rice variety, Jaya, treated with moderate doses of (10, 20 and 30 kR) gamma rays were subjected to study the relative magnitude of induced variability and the type of mutations induced for height of plant in M 2 and M 3 generations. Progenies of 3352 M 1 spikes, totalling to 35691 M 2 plants and their subsequent progenies in M 3 were analysed. To get wider variability, very large populations in all the generations were studied. The mean value, genetic variance and phenotypic frequency distribution with and between generations were studied. The treated population showed no significant shift in mean values from that of control. The variance was greater in the irradiated material compared to control. The variability was found to shift in both plus and minus direction from that of control with a higher frequency in the minus direction in M 2 . A high frequency of dwarf mutants was observed in 20 kR treated population in the M 2 generation. The segregation ratio was higher in M 2 compared to M 3 generation. (author)

  1. Radio Frequency Interference Mitigation

    Science.gov (United States)

    An, T.; Chen, X.; Mohan, P.; Lao, B. Q.

    2017-09-01

    The observational facilities of radio astronomy keep constant upgrades and developments to achieve better capabilities including increasing the time of the data recording and frequency resolutions, and increasing the receiving and recording bandwidth. However in contrast, only a limited spectrum resource has been allocated to radio astronomy by the International Telecommunication Union, resulting in that the radio observational instrumentations are inevitably exposed to undesirable radio frequency interference (RFI) signals which originate mainly from the terrestrial human activity and are becoming stronger with time. RFIs degrade the quality of data and even lead to invalid data. The impact of RFIs on scientific outcome becomes more and more serious. In this article, the requirement for RFI mitigation is motivated, and the RFI characteristics, mitigation techniques, and strategies are reviewed. The mitigation strategies adopted at some representative observatories, telescopes, and arrays are also introduced. The advantages and shortcomings of the four classes of RFI mitigation strategies are discussed and presented, applicable at the connected causal stages: preventive, pre-detection, pre-correlation, and post-correlation. The proper identification and flagging of RFI is the key to the reduction of data loss and improvement in data quality, and is also the ultimate goal of developing RFI mitigation technique. This can be achieved through a strategy involving a combination of the discussed techniques in stages. The recent advances in the high speed digital signal processing and high performance computing allow for performing RFI excision of the large data volumes generated from large telescopes or arrays in both real time and offline modes, aiding the proposed strategy.

  2. Zinc allocation and re-allocation in rice

    NARCIS (Netherlands)

    Stomph, T.J.; Jiang, W.; Putten, van der P.E.L.; Struik, P.C.

    2014-01-01

    Aims: Agronomy and breeding actively search for options to enhance cereal grain Zn density. Quantifying internal (re-)allocation of Zn as affected by soil and crop management or genotype is crucial. We present experiments supporting the development of a conceptual model of whole plant Zn allocation

  3. Research on allocation efficiency of the daisy chain allocation algorithm

    Science.gov (United States)

    Shi, Jingping; Zhang, Weiguo

    2013-03-01

    With the improvement of the aircraft performance in reliability, maneuverability and survivability, the number of the control effectors increases a lot. How to distribute the three-axis moments into the control surfaces reasonably becomes an important problem. Daisy chain method is simple and easy to be carried out in the design of the allocation system. But it can not solve the allocation problem for entire attainable moment subset. For the lateral-directional allocation problem, the allocation efficiency of the daisy chain can be directly measured by the area of its subset of attainable moments. Because of the non-linear allocation characteristic, the subset of attainable moments of daisy-chain method is a complex non-convex polygon, and it is difficult to solve directly. By analyzing the two-dimensional allocation problems with a "micro-element" idea, a numerical calculation algorithm is proposed to compute the area of the non-convex polygon. In order to improve the allocation efficiency of the algorithm, a genetic algorithm with the allocation efficiency chosen as the fitness function is proposed to find the best pseudo-inverse matrix.

  4. Efficient Metropolitan Resource Allocation

    Directory of Open Access Journals (Sweden)

    Richard Arnott

    2016-05-01

    Full Text Available Over the past 30 years Calgary has doubled in size, from a population of 640,645 in 1985 to 1,230,915 in 2015. During that time the City has had five different mayors, hosted the Winter Olympics, and expanded the C-Train from 25 platforms to 45. Calgary’s Metropolitan Area has grown too, with Airdrie, Chestermere, Okotoks and Cochrane growing into full-fledged cities, ripe with inter-urban commuters.* And with changes to provincial legislation in the mid-’90s, rural Rocky View County and the Municipal District of Foothills are now real competitors for residential, commercial and industrial development that in the past would have been considered urban. In this metropolitan system, where people live, their household structure, and their place of work informs the services they need to conduct their daily lives, and directly impacts the spatial character of the City and the broader region. In sum, Metropolitan Calgary is increasingly complex. Calgary and the broader metropolitan area will continue to grow, even with the current economic slowdown. Frictions within Calgary, between the various municipalities in the metropolitan area, and the priorities of other local authorities (such as the School Boards and Alberta Health Services will continue to impact the agendas of local politicians and their ability to answer to the needs of their residents. How resources – whether it is hard infrastructure, affordable housing, classrooms, or hospital beds – are allocated over space and how these resources are funded, directly impacts these relationships. This technical paper provides my perspective as an urban economist on the efficient allocation of resources within a metropolitan system in general, with reference to Calgary where appropriate, and serves as a companion to the previously released “Reflections on Calgary’s Spatial Structure: An Urban Economists Critique of Municipal Planning in Calgary.” It is hoped that the concepts reviewed

  5. Spectrum and Frequency of the GJB2 Gene Pathogenic Variants in a Large Cohort of Patients with Hearing Impairment Living in a Subarctic Region of Russia (the Sakha Republic.

    Directory of Open Access Journals (Sweden)

    Nikolay A Barashkov

    Full Text Available Pathogenic variants in the GJB2 gene, encoding connexin 26, are known to be a major cause of hearing impairment (HI. More than 300 allelic variants have been identified in the GJB2 gene. Spectrum and allelic frequencies of the GJB2 gene vary significantly among different ethnic groups worldwide. Until now, the spectrum and frequency of the pathogenic variants in exon 1, exon 2 and the flanking intronic regions of the GJB2 gene have not been described thoroughly in the Sakha Republic (Yakutia, which is located in a subarctic region in Russia. The complete sequencing of the non-coding and coding regions of the GJB2 gene was performed in 393 patients with HI (Yakuts-296, Russians-51, mixed and other ethnicities-46 and in 187 normal hearing individuals of Yakut (n = 107 and Russian (n = 80 populations. In the total sample (n = 580, we revealed 12 allelic variants of the GJB2 gene, 8 of which were recessive pathogenic variants. Ten genotypes with biallelic recessive pathogenic variants in the GJB2 gene (in a homozygous or a compound heterozygous state were found in 192 out of 393 patients (48.85%. We found that the most frequent GJB2 pathogenic variant in the Yakut patients was c.-23+1G>A (51.82% and that the second most frequent was c.109G>A (2.37%, followed by c.35delG (1.64%. Pathogenic variants с.35delG (22.34%, c.-23+1G>A (5.31%, and c.313_326del14 (2.12% were found to be the most frequent among the Russian patients. The carrier frequencies of the c.-23+1G>A and с.109G>A pathogenic variants in the Yakut control group were 10.20% and 2.80%, respectively. The carrier frequencies of с.35delG and c.101T>C were identical (2.5% in the Russian control group. We found that the contribution of the GJB2 gene pathogenic variants in HI in the population of the Sakha Republic (48.85% was the highest among all of the previously studied regions of Asia. We suggest that extensive accumulation of the c.-23+1G>A pathogenic variant in the indigenous Yakut

  6. Spectrum and Frequency of the GJB2 Gene Pathogenic Variants in a Large Cohort of Patients with Hearing Impairment Living in a Subarctic Region of Russia (the Sakha Republic).

    Science.gov (United States)

    Barashkov, Nikolay A; Pshennikova, Vera G; Posukh, Olga L; Teryutin, Fedor M; Solovyev, Aisen V; Klarov, Leonid A; Romanov, Georgii P; Gotovtsev, Nyurgun N; Kozhevnikov, Andrey A; Kirillina, Elena V; Sidorova, Oksana G; Vasilyevа, Lena M; Fedotova, Elvira E; Morozov, Igor V; Bondar, Alexander A; Solovyevа, Natalya A; Kononova, Sardana K; Rafailov, Adyum M; Sazonov, Nikolay N; Alekseev, Anatoliy N; Tomsky, Mikhail I; Dzhemileva, Lilya U; Khusnutdinova, Elza K; Fedorova, Sardana A

    2016-01-01

    Pathogenic variants in the GJB2 gene, encoding connexin 26, are known to be a major cause of hearing impairment (HI). More than 300 allelic variants have been identified in the GJB2 gene. Spectrum and allelic frequencies of the GJB2 gene vary significantly among different ethnic groups worldwide. Until now, the spectrum and frequency of the pathogenic variants in exon 1, exon 2 and the flanking intronic regions of the GJB2 gene have not been described thoroughly in the Sakha Republic (Yakutia), which is located in a subarctic region in Russia. The complete sequencing of the non-coding and coding regions of the GJB2 gene was performed in 393 patients with HI (Yakuts-296, Russians-51, mixed and other ethnicities-46) and in 187 normal hearing individuals of Yakut (n = 107) and Russian (n = 80) populations. In the total sample (n = 580), we revealed 12 allelic variants of the GJB2 gene, 8 of which were recessive pathogenic variants. Ten genotypes with biallelic recessive pathogenic variants in the GJB2 gene (in a homozygous or a compound heterozygous state) were found in 192 out of 393 patients (48.85%). We found that the most frequent GJB2 pathogenic variant in the Yakut patients was c.-23+1G>A (51.82%) and that the second most frequent was c.109G>A (2.37%), followed by c.35delG (1.64%). Pathogenic variants с.35delG (22.34%), c.-23+1G>A (5.31%), and c.313_326del14 (2.12%) were found to be the most frequent among the Russian patients. The carrier frequencies of the c.-23+1G>A and с.109G>A pathogenic variants in the Yakut control group were 10.20% and 2.80%, respectively. The carrier frequencies of с.35delG and c.101T>C were identical (2.5%) in the Russian control group. We found that the contribution of the GJB2 gene pathogenic variants in HI in the population of the Sakha Republic (48.85%) was the highest among all of the previously studied regions of Asia. We suggest that extensive accumulation of the c.-23+1G>A pathogenic variant in the indigenous Yakut

  7. Endogeneously arising network allocation rules

    NARCIS (Netherlands)

    Slikker, M.

    2006-01-01

    In this paper we study endogenously arising network allocation rules. We focus on three allocation rules: the Myerson value, the position value and the component-wise egalitarian solution. For any of these three rules we provide a characterization based on component efficiency and some balanced

  8. Carbon allocation in forest ecosystems

    Science.gov (United States)

    Creighton M. Litton; James W. Raich; Michael G. Ryan

    2007-01-01

    Carbon allocation plays a critical role in forest ecosystem carbon cycling. We reviewed existing literature and compiled annual carbon budgets for forest ecosystems to test a series of hypotheses addressing the patterns, plasticity, and limits of three components of allocation: biomass, the amount of material present; flux, the flow of carbon to a component per unit...

  9. Risk allocation under liquidity constraints

    NARCIS (Netherlands)

    Csóka, P.; Herings, P.J.J.

    2013-01-01

    Risk allocation games are cooperative games that are used to attribute the risk of a financial entity to its divisions. In this paper, we extend the literature on risk allocation games by incorporating liquidity considerations. A liquidity policy specifies state-dependent liquidity requirements that

  10. Dependence of the frequency spectrum of small amplitude vibrations superimposed on finite deformations of a nonlinear, cylindrical elastic body on residual stress

    KAUST Repository

    Gorb, Yuliya

    2010-11-01

    We model and analyze the response of nonlinear, residually stressed elastic bodies subjected to small amplitude vibrations superimposed upon large deformations. The problem derives from modeling the use of intravascular ultrasound (IVUS) imaging to interrogate atherosclerotic plaques in vivo in large arteries. The goal of this investigation is twofold: (i) introduce a modeling framework for residual stress that unlike traditional Fung type classical opening angle models may be used for a diseased artery, and (ii) investigate the sensitivity of the spectra of small amplitude high frequency time harmonic vibrations superimposed on a large deformation to the details of the residual stress stored in arteries through a numerical simulation using physiologic parameter values under both low and high blood pressure loadings. The modeling framework also points the way towards an inverse problem using IVUS techniques to estimate residual stress in healthy and diseased arteries. © 2010 Elsevier Ltd. All rights reserved.

  11. IR visible sum-frequency vibrational spectroscopy of Biphenyl-3 methylene thiol monolayer on gold and silver: effect of the visible wavelength on the SFG spectrum

    Science.gov (United States)

    Humbert, C.; Dreesen, L.; Mani, A. A.; Caudano, Y.; Lemaire, J.-J.; Thiry, P. A.; Peremans, A.

    2002-04-01

    We measured IR-visible sum-frequency generation spectra of CH 3-(C 6H 4) 2-(CH 2) 3-S-H (Biphenyl-3) self-assembled monolayers on a silver and a gold substrate. For the latter substrate, we observed different interference patterns between the resonant signal of the CH vibration and the non-resonant contribution of the substrate as a function of the visible beam wavelength. The non-linear response of the gold substrate is enhanced around 480 nm corresponding to the s-d interband transition. Such effect is not observed for the silver substrate the interband transition of which is located out of the investigated visible spectral range of 450-700 nm.

  12. Power-law spectra found in plant signal of the Borssele NPP. An analysis using wavelet. Application of wavelet for wide-frequency range investigation and investigation (spectrum) for the secondary system signals

    International Nuclear Information System (INIS)

    Suzudo, T.; Verhoef, J.P.; Tuerkcan, E.

    1996-09-01

    Power-law spectra were found in the temperature signals of the secondary loop in the Borssele Nuclear Power Plant, a PWR in the Netherlands. The coolant temperature before the steam generator inlet was found to fluctuate such that its power spectrum density S, follows S∝f -α , where α is ∝4/3. Analyses using PSD suggested that the value of α is roughly constant over years. Detailed analyses were conducted using wavelet, with the discovery that the power-law appears constantly only at around 0.1 Hz, and the estimated α was found between 1.26 and 1.36. The feedwater pressure signal and feedwater flow rate signal in the same frequency range were white noise and Borwnian motion respectively, and the indication of α=4/3 was not found from them. (orig.)

  13. Estudo do espectro sonoro nos limiares de altas frequências em trabalhadores expostos ao ruído Study of the noise spectrum on high frequency thresholds in workers exposed to noise

    Directory of Open Access Journals (Sweden)

    Aurea Oliveira Canha Ottoni

    2012-08-01

    Full Text Available O grau de nocividade do ruído pode ser quantificado e qualificado com base em algumas características do som como sua intensidade, o tipo de espectro, duração e a distribuição da exposição ao ruído durante a jornada de trabalho. OBJETIVO: Avaliar o espectro de ruído e a configuração audiométrica em trabalhadores. MATERIAIS E MÉTODOS: Estudo de coorte contemporânea com corte transversal, realizado no Distrito Federal. Realizou-se avaliação ambiental (análise espectral do ruído em empresas de diferentes ramos de atividade econômica e avaliação audiológica em 347 trabalhadores. RESULTADOS: A análise espectral revelou picos em diferentes frequências em cada ramo de atividade (8 kHz-metalúrgico, 4 kHz-marmoraria e 2 kHz-madeireira. Verificou-se que as frequências de 14 kHz e 16 kHz apresentaram diferenças significativas entre os ramos de atividade, com maior prevalência no metalúrgico. CONCLUSÃO: A utilização de medidor de nível de pressão sonora, acoplado a analisador de frequência e a avaliação audiométrica de altas frequências possibilitam a detecção precoce de danos auditivos que, por sua vez, viabiliza melhor direcionamento das ações preventivas.Noise level can be quantified and qualified based on sound characteristics such as intensity, type of spectrum, duration and distribution of the noise exposure during one's working hours. OBJECTIVE: To assess noise spectrum and the audiometric configuration of workers. MATERIALS AND METHODS: Contemporary cross-sectional cohort carried out in the Federal District - Brazil. We did an environmental analysis (spectral analysis of the noise in companies from different industries, with audiological assessment of 347 workers. RESULTS: The spectral analysis revealed peaks at different frequencies for each industry investigated (8 kHz-metallurgical, 4 kHz-stone Works and 2 kHz-wood works. We noticed that the frequencies of 14 kHz and 16 kHz had significant differences

  14. Was The Electromagnetic Spectrum A Blackbody Spectrum In The Early Universe?

    International Nuclear Information System (INIS)

    Opher, M.; Opher, R.

    1997-01-01

    It is generally assumed that the electromagnetic spectrum in the primordial universe was a blackbody spectrum in vacuum. We derive the electromagnetic spectrum based on the fluctuation-dissipation theorem that describes the electromagnetic fluctuations in a plasma. Our description includes thermal and collisional effects in a plasma. The electromagnetic spectrum obtained differs from a blackbody spectrum in vacuum at low frequencies. In particular, concentrating on the primordial nucleosynthesis era, it has more energy than the blackbody spectrum for frequencies less than 3ω pe to 6ω pe , where ω pe is the electron plasma frequency. copyright 1997 The American Physical Society

  15. Cloud based spectrum manager for future wireless regulatory environment

    CSIR Research Space (South Africa)

    Masonta, MT

    2015-12-01

    Full Text Available The regulatory environment in radio frequency spectrum management lags the advancement of wireless technologies, especially in the area of cognitive radio and dynamic spectrum access. In this paper we argue that the solution towards spectrum Pareto...

  16. Towards dynamic spectrum access and 5G, via television white spaces

    CSIR Research Space (South Africa)

    Lysko, Albert A

    2017-05-01

    Full Text Available allocations towards sharing the spectrum between different technologies in a dynamic fashion. The key focus will be on the developments in television white space and geolocation spectrum database methods and technologies, with mention of parallels to LTE....

  17. Fast radio burst search: cross spectrum vs. auto spectrum method

    Science.gov (United States)

    Liu, Lei; Zheng, Weimin; Yan, Zhen; Zhang, Juan

    2018-06-01

    The search for fast radio bursts (FRBs) is a hot topic in current radio astronomy studies. In this work, we carry out a single pulse search with a very long baseline interferometry (VLBI) pulsar observation data set using both auto spectrum and cross spectrum search methods. The cross spectrum method, first proposed in Liu et al., maximizes the signal power by fully utilizing the fringe phase information of the baseline cross spectrum. The auto spectrum search method is based on the popular pulsar software package PRESTO, which extracts single pulses from the auto spectrum of each station. According to our comparison, the cross spectrum method is able to enhance the signal power and therefore extract single pulses from data contaminated by high levels of radio frequency interference (RFI), which makes it possible to carry out a search for FRBs in regular VLBI observations when RFI is present.

  18. Zinc allocation and re-allocation in rice

    Science.gov (United States)

    Stomph, Tjeerd Jan; Jiang, Wen; Van Der Putten, Peter E. L.; Struik, Paul C.

    2014-01-01

    Aims: Agronomy and breeding actively search for options to enhance cereal grain Zn density. Quantifying internal (re-)allocation of Zn as affected by soil and crop management or genotype is crucial. We present experiments supporting the development of a conceptual model of whole plant Zn allocation and re-allocation in rice. Methods: Two solution culture experiments using 70Zn applications at different times during crop development and an experiment on within-grain distribution of Zn are reported. In addition, results from two earlier published experiments are re-analyzed and re-interpreted. Results: A budget analysis showed that plant zinc accumulation during grain filling was larger than zinc allocation to the grains. Isotope data showed that zinc taken up during grain filling was only partly transported directly to the grains and partly allocated to the leaves. Zinc taken up during grain filling and allocated to the leaves replaced zinc re-allocated from leaves to grains. Within the grains, no major transport barrier was observed between vascular tissue and endosperm. At low tissue Zn concentrations, rice plants maintained concentrations of about 20 mg Zn kg−1 dry matter in leaf blades and reproductive tissues, but let Zn concentrations in stems, sheath, and roots drop below this level. When plant zinc concentrations increased, Zn levels in leaf blades and reproductive tissues only showed a moderate increase while Zn levels in stems, roots, and sheaths increased much more and in that order. Conclusions: In rice, the major barrier to enhanced zinc allocation towards grains is between stem and reproductive tissues. Enhancing root to shoot transfer will not contribute proportionally to grain zinc enhancement. PMID:24478788

  19. The spectrum of HNF1A gene mutations in Greek patients with MODY3: relative frequency and identification of seven novel germline mutations.

    Science.gov (United States)

    Tatsi, Christina; Kanaka-Gantenbein, Christina; Vazeou-Gerassimidi, Adriani; Chrysis, Dionysios; Delis, Dimitrios; Tentolouris, Nikolaos; Dacou-Voutetakis, Catherine; Chrousos, George P; Sertedaki, Amalia

    2013-11-01

    Maturity-Onset Diabetes of the Young (MODY) is the most common type of monogenic diabetes accounting for 1-2% of the population with diabetes. The relative incidence of HNF1A-MODY (MODY3) is high in European countries; however, data are not available for the Greek population. The aims of this study were to determine the relative frequency of MODY3 in Greece, the type of the mutations observed, and their relation to the phenotype of the patients. Three hundred ninety-five patients were referred to our center because of suspected MODY during a period of 15 yr. The use of Denaturing Gradient Gel Electrophoresis of polymerase chain reaction amplified DNA revealed 72 patients carrying Glucokinase gene mutations (MODY2) and 8 patients carrying HNF1A gene mutations (MODY3). After using strict criteria, 54 patients were selected to be further evaluated by direct sequencing or by multiplex ligation probe amplification (MLPA) for the presence of HNF1A gene mutations. In 16 unrelated patients and 13 of their relatives, 15 mutations were identified in the HNF1A gene. Eight of these mutations were previously reported, whereas seven were novel. Clinical features, such as age of diabetes at diagnosis or severity of hyperglycemia, were not related to the mutation type or location. In our cohort of patients fulfilling strict clinical criteria for MODY, 12% carried an HNF1A gene mutation, suggesting that defects of this gene are responsible for a significant proportion of monogenic diabetes in the Greek population. No clear phenotype-genotype correlations were identified. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Joint Electromagnetic Spectrum Management Operations

    Science.gov (United States)

    2012-03-20

    promulgate command-specific policy and guidance for EMS use, the joint restricted frequency list (JRFL) process, the joint communications–electronics...joint communications–electronics operating instructions (JCEOI) and joint restricted frequency list (JRFL). Examples of FM include providing the...joint restricted frequency list Figure III-4. Joint Frequency Management Office Spectrum Management Process Chapter III III-10 JP 6-01 assignments

  1. Matching Theory for Channel Allocation in Cognitive Radio Networks

    Directory of Open Access Journals (Sweden)

    L. Cao

    2016-12-01

    Full Text Available For a cognitive radio network (CRN in which a set of secondary users (SUs competes for a limited number of channels (spectrum resources belonging to primary users (PUs, the channel allocation is a challenge and dominates the throughput and congestion of the network. In this paper, the channel allocation problem is first formulated as the 0-1 integer programming optimization, with considering the overall utility both of primary system and secondary system. Inspired by matching theory, a many-to-one matching game is used to remodel the channel allocation problem, and the corresponding PU proposing deferred acceptance (PPDA algorithm is also proposed to yield a stable matching. We compare the performance and computation complexity between these two solutions. Numerical results demonstrate the efficiency and obtain the communication overhead of the proposed scheme.

  2. International Development Aid Allocation Determinants

    OpenAIRE

    Tapas Mishra; Bazoumana Ouattara; Mamata Parhi

    2012-01-01

    This paper investigates the factors explaining aid allocation by bilateral and multilateral donors. We use data for 146 aid recipient countries over the period 1990-2007 and employ Bayesian Averaging of Classical Estimates Approach (BACE) approach and find that both the recipient need and donor interest motives are `significant' determinants of bilateral and multilateral aid allocation process. Our results also indicate that the measures for recipient need and donor interests vary from bilate...

  3. Application of an allocation methodology

    International Nuclear Information System (INIS)

    Youngblood, R.

    1989-01-01

    This paper presents a method for allocating resources to elements of a system for the purpose of achieving prescribed levels of defense-in-depth at minimal cost. The method makes extensive use of logic modelling. An analysis of a simplified high-level waste repository is used as an illustrative application of the method. It is shown that it is possible to allocate quality control costs (or demonstrate performance) in an optimal way over elements of a conceptual design

  4. Joint sub-carrier pairing and resource allocation for cognitive networks with adaptive relaying

    KAUST Repository

    Soury, Hamza; Bader, F.; Shaat, M.; Alouini, Mohamed-Slim

    2013-01-01

    Relayed transmission in a cognitive radio (CR) environment could be used to increase the coverage and capacity of communication system that benefits already from the efficient management of the spectrum developed by CR. Furthermore, there are many types of cooperative communications, including decode-and-forward (DAF) and amplify-and-forward (AAF). In this paper, these techniques are combined in an adaptive mode to benefit from its forwarding advantages; this mode is called adaptive relaying protocol (ARP). Moreover, this work focuses on the joint power allocation in a cognitive radio system in a cooperative mode that operates ARP in multi-carrier mode. The multi-carrier scenario is used in an orthogonal frequency division multiplexing (OFDM) mode, and the problem is formulated to maximize the end-to-end rate by searching the best power allocation at the transmitters. This work includes, besides the ARP model, a sub-carrier pairing strategy that allows the relays to switch to the best sub-carrier pairs to increase the throughput. The optimization problem is formulated and solved under the interference and power budget constraints using the sub-gradient algorithm. The simulation results confirm the efficiency of the proposed adaptive relaying protocol in comparison to other relaying techniques. The results show also the consequence of the choice of the pairing strategy. 2013 Stolojescu-Crisan and Isar; licensee Springer.

  5. Joint sub-carrier pairing and resource allocation for cognitive networks with adaptive relaying

    KAUST Repository

    Soury, Hamza

    2013-11-09

    Relayed transmission in a cognitive radio (CR) environment could be used to increase the coverage and capacity of communication system that benefits already from the efficient management of the spectrum developed by CR. Furthermore, there are many types of cooperative communications, including decode-and-forward (DAF) and amplify-and-forward (AAF). In this paper, these techniques are combined in an adaptive mode to benefit from its forwarding advantages; this mode is called adaptive relaying protocol (ARP). Moreover, this work focuses on the joint power allocation in a cognitive radio system in a cooperative mode that operates ARP in multi-carrier mode. The multi-carrier scenario is used in an orthogonal frequency division multiplexing (OFDM) mode, and the problem is formulated to maximize the end-to-end rate by searching the best power allocation at the transmitters. This work includes, besides the ARP model, a sub-carrier pairing strategy that allows the relays to switch to the best sub-carrier pairs to increase the throughput. The optimization problem is formulated and solved under the interference and power budget constraints using the sub-gradient algorithm. The simulation results confirm the efficiency of the proposed adaptive relaying protocol in comparison to other relaying techniques. The results show also the consequence of the choice of the pairing strategy. 2013 Stolojescu-Crisan and Isar; licensee Springer.

  6. Location-based resource allocation for OFDMA cognitive radio systems

    KAUST Repository

    Nam, Haewoon

    2010-01-01

    In cognitive radio systems, in order for the secondary users to opportunistically share the spectrum without interfering the primary users, an accurate spectrum measurement and a precise estimation of the interference at the primary users are necessary but are challenging tasks. Since it is impractical in cognitive radio systems to assume that the channel state information of the interference link is available at the cognitive transmitter, the interference at the primary users is hard to be estimated accurately. This paper introduces a resource allocation algorithm for OFDMA-based cognitive radio systems, which utilizes location information of the primary and secondary users instead of the channel state information of the interference link. Simulation results show that it is indeed effective to incorporate location information into resource allocation so that a near-optimal capacity is achieved.

  7. How should INGOs allocate resources?

    Directory of Open Access Journals (Sweden)

    Scott Wisor

    2012-02-01

    Full Text Available International Non-governmental Organizations (INGOs face difficult choices when choosing to allocate resources. Given that the resources made available to INGOs fall far short of what is needed to reduce massive human rights deficits, any chosen scheme of resource allocation requires failing to reach other individuals in great need. Facing these moral opportunity costs, what moral reasons should guide INGO resource allocation? Two reasons that clearly matter, and are recognized by philosophers and development practitioners, are the consequences (or benefit or harm reduction of any given resource allocation and the need (or priority of individual beneficiaries. If accepted, these reasons should lead INGOs to allocate resources to a limited number of countries where the most prioritarian weighted harm reduction will be achieved. I make three critiques against this view. First, on grounds the consequentialist accepts, I argue that INGOs ought to maintain a reasonably wide distribution of resources. Second, I argue that even if one is a consequentialist, consequentialism ought not act as an action guiding principle for INGOs. Third, I argue that additional moral reasons should influence decision making about INGO resource allocation. Namely, INGO decision making should attend to relational reasons, desert, respect for agency, concern for equity, and the importance of expressing a view of moral wrongs.

  8. Energy Efficient Power Allocation for Cognitive MIMO Channels

    KAUST Repository

    Sboui, Lokman

    2016-01-06

    Two major issues are facing today s wireless communications evolution: -Spectrum scarcity: Need for more bandwidth. As a solution, the Cognitive Radio (CR) paradigm, where secondary users (unlicensed) share the spectrum with licensed users, was introduced. -Energy consumption and CO2 emission: The ICT produces 2% of global CO2 emission (equivalent to the aviation industry emission). The cellular networks produces 0.2%. As solution energy efficient systems should be designed rather than traditional spectral efficient systems. In this work, an energy efficient power allocation framework based on maximizing the average EE per parallel channel is presented.

  9. Game theoretic approaches for spectrum redistribution

    CERN Document Server

    Wu, Fan

    2014-01-01

    This brief examines issues of spectrum allocation for the limited resources of radio spectrum. It uses a game-theoretic perspective, in which the nodes in the wireless network are rational and always pursue their own objectives. It provides a systematic study of the approaches that can guarantee the system's convergence at an equilibrium state, in which the system performance is optimal or sub-optimal. The author provides a short tutorial on game theory, explains game-theoretic channel allocation in clique and in multi-hop wireless networks and explores challenges in designing game-theoretic m

  10. Spectrum Recombination.

    Science.gov (United States)

    Greenslade, Thomas B., Jr.

    1984-01-01

    Describes several methods of executing lecture demonstrations involving the recombination of the spectrum. Groups the techniques into two general classes: bringing selected portions of the spectrum together using lenses or mirrors and blurring the colors by rapid movement or foreshortening. (JM)

  11. Dynamic event Tress applied to sequences Full Spectrum LOCA. Calculating the frequency of exceedance of damage by integrated Safety Analysis Methodology; Arboles de sucesos dinamicos aplicados a secuencias Full Spectrum LOCA. Calculo de la frequencia de excedencia del dano mediante la metodologia Analisis Integrados de Seguridad (ISA)

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Magan, J. J.; Fernandez, I.; Gil, J.; Marrao, H.; Queral, C.; Gonzalez-Cadelo, J.; Montero-Mayorga, J.; Rivas, J.; Ibane-Llano, C.; Izquierdo, J. M.; Sanchez-Perea, M.; Melendez, E.; Hortal, J.

    2013-09-01

    The Integrated Safety Analysis (ISA) methodology, developed by the Spanish Nuclear Safety council (CSN), has been applied to obtain the dynamic Event Trees (DETs) for full spectrum Loss of Coolant Accidents (LOCAs) of a Westinghouse 3-loop PWR plant. The purpose of this ISA application is to obtain the Damage Exceedance Frequency (DEF) for the LOCA Event Tree by taking into account the uncertainties in the break area and the operator actuation time needed to cool down and de pressurize reactor coolant system by means of steam generator. Simulations are performed with SCAIS, a software tool which includes a dynamic coupling with MAAP thermal hydraulic code. The results show the capability of the ISA methodology to obtain the DEF taking into account the time uncertainty in human actions. (Author)

  12. Joint Resource Allocation for Dual - Band Heterogeneous Wireless Network

    DEFF Research Database (Denmark)

    Adeogun, Ramoni

    2018-01-01

    is proposed for adaptively switching the SC transmission frequency based on the location of small cell users and interference to macrocell users. We propose a resource allocation approach which maximizes the sum rate of small cell users while minimizing interference to macrocell users and the total power...

  13. Spectrum database as a service (SDaaS) for broadband innovation and efficient spectrum utilization

    CSIR Research Space (South Africa)

    Mfupe, L

    2013-10-01

    Full Text Available Broadband innovations for future wireless networks involves rapid sharing of radio frequency (RF) spectrum resources by means of dynamic spectrum access techniques (DSA) to satisfy immediate portfolio of heterogeneous demands of wireless IP services...

  14. Frequency-modulation transient absorption spectrum of the HCCl A 1A double-prime(0,0,0)left-arrow X 1A'(0,0,0) transition

    International Nuclear Information System (INIS)

    Chang, B.; Sears, T.J.

    1995-01-01

    The rotationally resolved spectrum of the HCCl A 1 A double-prime(0,0,0)left-arrow X 1 A'(0,0,0) transition between 12 230 and 12 410 cm -1 was obtained for the first time at Doppler-limited resolution using a frequency-modulation (FM) transient absorption technique. Five major subbands (K a =0 left-arrow 1, 1 left-arrow 0, 1 left-arrow 2, 2 left-arrow 1, and 2 left-arrow 3) of HC 35 Cl and one subband (K a =0 left-arrow 1) of HC 37 Cl were observed and assigned. In addition, the forbidden subband (K a =0 left-arrow 0) of HC 35 Cl was also observed. Thus far, we have assigned most (more than 70%) of the strong lines. The analysis of these subbands determines the geometry for the HCCl A(0,0,0) level: angle HCCl=134.7 degree and R C-Cl =1.623 A while R C-H is fixed at the corresponding value of CH 2 . The height of the barrier to linearity was found to be approximately 2170 cm -1 above the vibrationless level of the A state. The rotational structure of this spectrum shows irregular perturbations. Both random and J-dependent (anomalous K-type doubling) effects were observed. As in methylene, the perturbations most likely arise from Renner--Teller effect between the two singlet states in combination with spin--orbit coupling between the singlet and triplet states

  15. Cost allocation in distribution planning

    Energy Technology Data Exchange (ETDEWEB)

    Engevall, S

    1997-12-31

    This thesis concerns cost allocation problems in distribution planning. The cost allocation problems we study are illustrated using the distribution planning situation at the Logistics department of Norsk Hydro Olje AB. The planning situation is modeled as a Traveling Salesman Problem and a Vehicle Routing Problem with an inhomogeneous fleet. The cost allocation problems are the problems of how to divide the transportation costs among the customers served in each problem. The cost allocation problems are formulated as cooperative games, in characteristic function form, where the customers are defined to be the players. The games contain five and 21 players respectively. Game theoretical solution concepts such as the core, the nucleolus, the Shapley value and the {tau}-value are discussed. From the empirical results we can, among other things, conclude that the core of the Traveling Salesman Game is large, and that the core of the Vehicle Routing Game is empty. In the accounting of Norsk Hydro the cost per m{sup 3} can be found for each tour. We conclude that for a certain definition of the characteristic function, a cost allocation according to this principle will not be included in the core of the Traveling Salesman Game. The models and methods presented in this thesis can be applied to transportation problems similar to that of Norsk Hydro, independent of the type of products that are delivered. 96 refs, 11 figs, 26 tabs

  16. Cost allocation in distribution planning

    Energy Technology Data Exchange (ETDEWEB)

    Engevall, S.

    1996-12-31

    This thesis concerns cost allocation problems in distribution planning. The cost allocation problems we study are illustrated using the distribution planning situation at the Logistics department of Norsk Hydro Olje AB. The planning situation is modeled as a Traveling Salesman Problem and a Vehicle Routing Problem with an inhomogeneous fleet. The cost allocation problems are the problems of how to divide the transportation costs among the customers served in each problem. The cost allocation problems are formulated as cooperative games, in characteristic function form, where the customers are defined to be the players. The games contain five and 21 players respectively. Game theoretical solution concepts such as the core, the nucleolus, the Shapley value and the {tau}-value are discussed. From the empirical results we can, among other things, conclude that the core of the Traveling Salesman Game is large, and that the core of the Vehicle Routing Game is empty. In the accounting of Norsk Hydro the cost per m{sup 3} can be found for each tour. We conclude that for a certain definition of the characteristic function, a cost allocation according to this principle will not be included in the core of the Traveling Salesman Game. The models and methods presented in this thesis can be applied to transportation problems similar to that of Norsk Hydro, independent of the type of products that are delivered. 96 refs, 11 figs, 26 tabs

  17. Cost allocation in distribution planning

    International Nuclear Information System (INIS)

    Engevall, S.

    1996-01-01

    This thesis concerns cost allocation problems in distribution planning. The cost allocation problems we study are illustrated using the distribution planning situation at the Logistics department of Norsk Hydro Olje AB. The planning situation is modeled as a Traveling Salesman Problem and a Vehicle Routing Problem with an inhomogeneous fleet. The cost allocation problems are the problems of how to divide the transportation costs among the customers served in each problem. The cost allocation problems are formulated as cooperative games, in characteristic function form, where the customers are defined to be the players. The games contain five and 21 players respectively. Game theoretical solution concepts such as the core, the nucleolus, the Shapley value and the τ-value are discussed. From the empirical results we can, among other things, conclude that the core of the Traveling Salesman Game is large, and that the core of the Vehicle Routing Game is empty. In the accounting of Norsk Hydro the cost per m 3 can be found for each tour. We conclude that for a certain definition of the characteristic function, a cost allocation according to this principle will not be included in the core of the Traveling Salesman Game. The models and methods presented in this thesis can be applied to transportation problems similar to that of Norsk Hydro, independent of the type of products that are delivered. 96 refs, 11 figs, 26 tabs

  18. 47 CFR 2.104 - International Table of Frequency Allocations.

    Science.gov (United States)

    2010-10-01

    ... Union (ITU) has divided the world into three Regions 1 as shown in Figure 1 of this section and... as follows: (1) The term “African Broadcasting Area” means: (i) African countries, parts of countries...

  19. 47 CFR 2.106 - Table of Frequency Allocations.

    Science.gov (United States)

    2010-10-01

    ... medical (ISM) applications. Radiocommunication services operating within these bands must accept harmful... shall ensure that no harmful interference is caused thereby to the services to which the bands above 9 k..., Azerbaijan, Bulgaria, Georgia, Kyrgyzstan, the Russian Federation, Tajikistan and Turkmenistan, the band 14...

  20. UAS CNPC Satellite Link Performance - Sharing Spectrum with Terrestrial Systems

    Science.gov (United States)

    Kerczewski, Robert J.; Wilson, Jeffrey D.; Bishop, William D.

    2016-01-01

    In order to provide for the safe integration of unmanned aircraft systems into the National Airspace System, the control and non-payload communications (CNPC) link connecting the ground-based pilot with the unmanned aircraft must be highly reliable. A specific requirement is that it must operate using aviation safety radiofrequency spectrum. The 2012 World Radiocommunication Conference (WRC-12) provided a potentially suitable allocation for radio line-of-sight (LOS), terrestrial based CNPC link at 5030-5091 MHz. For a beyond radio line-of-sight (BLOS), satellite-based CNPC link, aviation safety spectrum allocations are currently inadequate. Therefore, the 2015 WRC will consider the use of Fixed Satellite Service (FSS) bands to provide BLOS CNPC under Agenda Item 1.5. This agenda item requires studies to be conducted to allow for the consideration of how unmanned aircraft can employ FSS for BLOS CNPC while maintaining existing systems. Since there are terrestrial Fixed Service systems also using the same frequency bands under consideration in Agenda Item 1.5 one of the studies required considered spectrum sharing between earth stations on-board unmanned aircraft and Fixed Service station receivers. Studies carried out by NASA have concluded that such sharing is possible under parameters previously established by the International Telecommunications Union. As the preparation for WRC-15 has progressed, additional study parameters Agenda Item 1.5 have been proposed, and some studies using these parameters have been added. This paper examines the study results for the original parameters as well as results considering some of the more recently proposed parameters to provide insight into the complicated process of resolving WRC-15 Agenda Item 1.5 and achieving a solution for BLOS CNPC for unmanned aircraft.

  1. Was The Electromagnetic Spectrum A Blackbody Spectrum In The Early Universe?

    OpenAIRE

    Opher, Merav; Opher, Reuven

    1997-01-01

    It is assumed, in general, that the electromagnetic spectrum in the Primordial Universe was a blackbody spectrum in vacuum. We derive the electromagnetic spectrum, based on the Fluctuation-Dissipation Theorem that describes the electromagnetic fluctuations in a plasma. Our description includes thermal and collisional effects in a plasma. The electromagnetic spectrum obtained differs from the blackbody spectrum in vacuum at low frequencies. In particular, concentrating on the primordial nucleo...

  2. Game Algorithm for Resource Allocation Based on Intelligent Gradient in HetNet

    Directory of Open Access Journals (Sweden)

    Fang Ye

    2017-02-01

    Full Text Available In order to improve system performance such as throughput, heterogeneous network (HetNet has become an effective solution in Long Term Evolution-Advanced (LET-A. However, co-channel interference leads to degradation of the HetNet throughput, because femtocells are always arranged to share the spectrum with the macro base station. In this paper, in view of the serious cross-layer interference in double layer HetNet, the Stackelberg game model is adopted to analyze the resource allocation methods of the network. Unlike the traditional system models only focusing on macro base station performance improvement, we take into account the overall system performance and build a revenue function with convexity. System utility functions are defined as the average throughput, which does not adopt frequency spectrum trading method, so as to avoid excessive signaling overhead. Due to the value scope of continuous Nash equilibrium of the built game model, the gradient iterative algorithm is introduced to reduce the computational complexity. As for the solution of Nash equilibrium, one kind of gradient iterative algorithm is proposed, which is able to intelligently choose adjustment factors. The Nash equilibrium can be quickly solved; meanwhile, the step of presetting adjustment factors is avoided according to network parameters in traditional linear iterative model. Simulation results show that the proposed algorithm enhances the overall performance of the system.

  3. Application of an allocation methodology

    International Nuclear Information System (INIS)

    Youngblood, R.; de Oliveira, L.F.S.

    1989-01-01

    This paper presents a method for allocating resources to elements of a system for the purpose of achieving prescribed levels of defense-in-depth at minimal cost. The method makes extensive use of logic modelling. An analysis of a simplified high-level waste repository is used as an illustrative application of the method. It is shown that it is possible to allocate quality control costs (or demonstrated performance) in an optimal way over elements of a conceptual design. 6 refs., 3 figs., 2 tabs

  4. Allocation Problems and Market Design

    DEFF Research Database (Denmark)

    Smilgins, Aleksandrs

    The thesis contains six independent papers with a common theme: Allocation problems and market design. The first paper is concerned with fair allocation of risk capital where independent autonomous subunits have risky activities and together constitute the entity's total risk, whose associated risk...... at a certain point in time involves countries that have excess demand and countries that have surplus of green energy. The problem addressed here is how the gains from trade ought to influence the way that members of the grid share common costs. The fifth paper extends the classical two-sided one...

  5. Prey risk allocation in a grazing ecosystem.

    Science.gov (United States)

    Gude, Justin A; Garrott, Robert A; Borkowski, John J; King, Fred

    2006-02-01

    Understanding the behaviorally mediated indirect effects of predators in ecosystems requires knowledge of predator-prey behavioral interactions. In predator-ungulate-plant systems, empirical research quantifying how predators affect ungulate group sizes and distribution, in the context of other influential variables, is particularly needed. The risk allocation hypothesis proposes that prey behavioral responses to predation risk depend on background frequencies of exposure to risk, and it can be used to make predictions about predator-ungulate-plant interactions. We determined non-predation variables that affect elk (Cervus elaphus) group sizes and distribution on a winter range in the Greater Yellowstone Ecosystem (GYE) using logistic and log-linear regression on surveys of 513 1-km2 areas conducted over two years. Employing model selection techniques, we evaluated risk allocation and other a priori hypotheses of elk group size and distributional responses to wolf (Canis lupus) predation risk while accounting for influential non-wolf-predation variables. We found little evidence that wolves affect elk group sizes, which were strongly influenced by habitat type and hunting by humans. Following predictions from the risk allocation hypothesis, wolves likely created a more dynamic elk distribution in areas that they frequently hunted, as elk tended to move following wolf encounters in those areas. This response should dilute elk foraging pressure on plant communities in areas where they are frequently hunted by wolves. We predict that this should decrease the spatial heterogeneity of elk impacts on grasslands in areas that wolves frequently hunt. We also predict that this should decrease browsing pressure on heavily browsed woody plant stands in certain areas, which is supported by recent research in the GYE.

  6. From efficacy to equity: Literature review of decision criteria for resource allocation and healthcare decisionmaking

    NARCIS (Netherlands)

    Guindo, L.A.; Wagner, M.; Baltussen, R.; Rindress, D.; van Til, Janine Astrid; Kind, P.; Goetghebeur, M.

    2012-01-01

    Objectives Resource allocation is a challenging issue faced by health policy decisionmakers requiring careful consideration of many factors. Objectives of this study were to identify decision criteria and their frequency reported in the literature on healthcare decisionmaking. Method An extensive

  7. Optimal power allocation for SM-OFDM systems with imperfect channel estimation

    International Nuclear Information System (INIS)

    Yu, Feng; Song, Lijun; Lei, Xia; Xiao, Yue; Jiang, Zhao Xiang; Jin, Maozhu

    2016-01-01

    This paper analyses the bit error rate (BER) of the spatial modulation orthogonal frequency division multiplex (SM-OFDM) system and derives the optimal power allocation between the data and the pilot symbols by minimizing the upper bound for the BER operating with imperfect channel estimation. Furthermore, we prove the proposed optimal power allocation scheme applies to all generalized linear interpolation techniques with the minimum mean square error (MMSE) channel estimation . Simulation results show that employing the proposed optimal power allocation provides a substantial gain in terms of the average BER performance for the SM-OFDM system compared to its equal-power-allocation counterpart.

  8. Coalition Formation and Spectrum Sharing of Cooperative Spectrum Sensing Participants.

    Science.gov (United States)

    Zhensheng Jiang; Wei Yuan; Leung, Henry; Xinge You; Qi Zheng

    2017-05-01

    In cognitive radio networks, self-interested secondary users (SUs) desire to maximize their own throughput. They compete with each other for transmit time once the absence of primary users (PUs) is detected. To satisfy the requirement of PU protection, on the other hand, they have to form some coalitions and cooperate to conduct spectrum sensing. Such dilemma of SUs between competition and cooperation motivates us to study two interesting issues: 1) how to appropriately form some coalitions for cooperative spectrum sensing (CSS) and 2) how to share transmit time among SUs. We jointly consider these two issues, and propose a noncooperative game model with 2-D strategies. The first dimension determines coalition formation, and the second indicates transmit time allocation. Considering the complexity of solving this game, we decompose the game into two more tractable ones: one deals with the formation of CSS coalitions, and the other focuses on the allocation of transmit time. We characterize the Nash equilibria (NEs) of both games, and show that the combination of these two NEs corresponds to the NE of the original game. We also develop a distributed algorithm to achieve a desirable NE of the original game. When this NE is achieved, the SUs obtain a Dhp-stable coalition structure and a fair transmit time allocation. Numerical results verify our analyses, and demonstrate the effectiveness of our algorithm.

  9. The Normalized-Rate Iterative Algorithm: A Practical Dynamic Spectrum Management Method for DSL

    Directory of Open Access Journals (Sweden)

    Statovci Driton

    2006-01-01

    Full Text Available We present a practical solution for dynamic spectrum management (DSM in digital subscriber line systems: the normalized-rate iterative algorithm (NRIA. Supported by a novel optimization problem formulation, the NRIA is the only DSM algorithm that jointly addresses spectrum balancing for frequency division duplexing systems and power allocation for the users sharing a common cable bundle. With a focus on being implementable rather than obtaining the highest possible theoretical performance, the NRIA is designed to efficiently solve the DSM optimization problem with the operators' business models in mind. This is achieved with the help of two types of parameters: the desired network asymmetry and the desired user priorities. The NRIA is a centralized DSM algorithm based on the iterative water-filling algorithm (IWFA for finding efficient power allocations, but extends the IWFA by finding the achievable bitrates and by optimizing the bandplan. It is compared with three other DSM proposals: the IWFA, the optimal spectrum balancing algorithm (OSBA, and the bidirectional IWFA (bi-IWFA. We show that the NRIA achieves better bitrate performance than the IWFA and the bi-IWFA. It can even achieve performance almost as good as the OSBA, but with dramatically lower requirements on complexity. Additionally, the NRIA can achieve bitrate combinations that cannot be supported by any other DSM algorithm.

  10. The Normalized-Rate Iterative Algorithm: A Practical Dynamic Spectrum Management Method for DSL

    Science.gov (United States)

    Statovci, Driton; Nordström, Tomas; Nilsson, Rickard

    2006-12-01

    We present a practical solution for dynamic spectrum management (DSM) in digital subscriber line systems: the normalized-rate iterative algorithm (NRIA). Supported by a novel optimization problem formulation, the NRIA is the only DSM algorithm that jointly addresses spectrum balancing for frequency division duplexing systems and power allocation for the users sharing a common cable bundle. With a focus on being implementable rather than obtaining the highest possible theoretical performance, the NRIA is designed to efficiently solve the DSM optimization problem with the operators' business models in mind. This is achieved with the help of two types of parameters: the desired network asymmetry and the desired user priorities. The NRIA is a centralized DSM algorithm based on the iterative water-filling algorithm (IWFA) for finding efficient power allocations, but extends the IWFA by finding the achievable bitrates and by optimizing the bandplan. It is compared with three other DSM proposals: the IWFA, the optimal spectrum balancing algorithm (OSBA), and the bidirectional IWFA (bi-IWFA). We show that the NRIA achieves better bitrate performance than the IWFA and the bi-IWFA. It can even achieve performance almost as good as the OSBA, but with dramatically lower requirements on complexity. Additionally, the NRIA can achieve bitrate combinations that cannot be supported by any other DSM algorithm.

  11. Regulating nutrient allocation in plants

    Science.gov (United States)

    Udvardi, Michael; Yang, Jiading; Worley, Eric

    2014-12-09

    The invention provides coding and promoter sequences for a VS-1 and AP-2 gene, which affects the developmental process of senescence in plants. Vectors, transgenic plants, seeds, and host cells comprising heterologous VS-1 and AP-2 genes are also provided. Additionally provided are methods of altering nutrient allocation and composition in a plant using the VS-1 and AP-2 genes.

  12. Centralized Allocation in Multiple Markets

    DEFF Research Database (Denmark)

    Monte, Daniel; Tumennasan, Norovsambuu

    The problem of allocating indivisible objects to different agents, where each indi vidual is assigned at most one object, has been widely studied. Pápai (2000) shows that the set of strategy-proof, nonbossy, Pareto optimal and reallocation-proof rules are hierarchical exchange rules | generalizat...... and nonbossy rules are sequential dictatorships, a special case of Pápai's hierarchical exchange rules....

  13. Designing for dynamic task allocation

    NARCIS (Netherlands)

    Dongen, van K.; Maanen, van P.P.

    2005-01-01

    Future platforms are envisioned in which human-machine teams are able to share and trade tasks as demands in situations change. It seems that human-machine coordination has not received the attention it deserves by past and present approaches to task allocation. In this paper a simple way to make

  14. Planning and Resource Allocation Management.

    Science.gov (United States)

    Coleman, Jack W.

    1986-01-01

    Modern scientific management techniques provide college administrators with valuable planning and resource allocation insights and enhances the decision process. The planning model should incorporate assessment, strategic planning, dynamic and long-term budgeting, operational planning, and feedback and control for actual operations. (MSE)

  15. New resource allocation scheme for cognitive relay networks with opportunistic access

    KAUST Repository

    Zafar, Ammar

    2012-06-01

    In this paper, a new resource allocation scheme to minimize Symbol Error rate (SER) for relay assisted cognitive radio networks is studied. A cognitive relay network with amplify-and-forward (AF) fixed gain relays and opportunistic access to the licensed spectrum is considered. The SER objective function and the optimization constraints are derived first. The resource allocation algorithm is then derived using the Langrangian multiplier method. Closed form expressions are derived for the source and relay powers and, symbol time. Analytical results show that the optimal power allocation follows an extended water-filling solution. © 2012 IEEE.

  16. Cognitive radio networks efficient resource allocation in cooperative sensing, cellular communications, high-speed vehicles, and smart grid

    CERN Document Server

    Jiang, Tao; Cao, Yang

    2015-01-01

    PrefaceAcknowledgmentsAbout the AuthorsIntroductionCognitive Radio-Based NetworksOpportunistic Spectrum Access NetworksCognitive Radio Networks with Cooperative SensingCognitive Radio Networks for Cellular CommunicationsCognitive Radio Networks for High-Speed VehiclesCognitive Radio Networks for a Smart GridContent and OrganizationTransmission Slot Allocation in an Opportunistic Spectrum Access NetworkSingle-User Single-Channel System ModelProbabilistic Slot Allocation SchemeOptimal Probabilistic Slot AllocationBaseline PerformanceExponential DistributionHyper-Erlang DistributionPerformance An

  17. Optimal allocation of international atomic energy agency inspection resources

    International Nuclear Information System (INIS)

    Markin, J.T.

    1987-01-01

    Each year the Department of Safeguards of the International Atomic Energy Agency (IAEA) conducts inspections to confirm that nuclear materials and facilities are employed for peaceful purposes. Because of limited inspection resources, however, the IAEA cannot fully attain its safeguards goals either quantitatively as measured by the inspection effort negotiated in the facility attachments or qualitatively as measured by the IAEA criteria for evaluating attainment of safeguards goals. Under current IAEA procedures the allocation of inspection resources assigns essentially equal inspection effort to facilities of the same type. An alternative approach would incorporate consideration of all material categories and facilities to be assigned inspection resources when allocating effort to a particular facility. One such method for allocating inspection resources is based on the IAEA criteria. The criteria provide a framework for allocating inspection effort that includes a ranking of material types according to their safeguards importance, an implicit definition of inspection activities for each material and facility type, and criteria for judging the attainment of safeguards goals in terms of the quality and frequency of these inspection activities. This framework is applicable to resource allocation for an arbitrary group of facilities such as a state's fuel cycle, the facilities inspected by an operations division, or all of the facilities inspected by the IAEA

  18. Zellweger Spectrum

    Science.gov (United States)

    ... severe defect, resulting in essentially nonfunctional peroxisomes. This phenomenon produces the range of severity of the disorders. How is the Zellweger Spectrum Diagnosed? The distinctive shape of the head and face of a child born with one of the diseases of the ...

  19. Energy-Efficient Power Allocation for Cognitive MIMO Channels

    KAUST Repository

    Sboui, Lokman

    2017-03-20

    Due to the massive data traffic in wireless networks, energy consumption has become a crucial concern, especially with the limited power supply of the mobile terminals and the increasing CO2 emission of the cellular industry. In this context, we study the energy efficiency (EE) of MIMO spectrum sharing cognitive radio (CR) systems under power and interference constraints. We present an energy-efficient power allocation framework based on maximizing the average EE per parallel channel resulting from the singular value decomposition (SVD) eigenmode transmission. We also present a sub-optimal low-complexity power allocation scheme based on the water-filling power allocation. In the numerical results, we show that the sub-optimal power allocation achieves at least 95% of the optimal performance. In addition, we show that adopting more antennas is more energy efficient for a given power budget. Finally, we show that the interference threshold has a significant effect on both the EE and the spectral efficiency at high-power regime.

  20. Combined exposure to X-irradiation followed by N-ethyl-N-nitrosourea treatment alters the frequency and spectrum of Ikaros point mutations in murine T-cell lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Kakinuma, Shizuko, E-mail: skakinum@nirs.go.jp [Radiobiology for Children' s Health Research Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Nishimura, Mayumi; Amasaki, Yoshiko; Takada, Mayumi; Yamauchi, Kazumi; Sudo, Satomi; Shang, Yi [Radiobiology for Children' s Health Research Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Doi, Kazutaka; Yoshinaga, Shinji [Regulatory Sciences Research Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Shimada, Yoshiya [Radiobiology for Children' s Health Research Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan)

    2012-09-01

    Ionizing radiation is a well-known carcinogen, but its potency may be influenced by other environmental carcinogens, which is of practical importance in the assessment of risk. Data are scarce, however, on the combined effect of radiation with other environmental carcinogens and the underlying mechanisms involved. We studied the mode and mechanism of the carcinogenic effect of radiation in combination with N-ethyl-N-nitrosourea (ENU) using doses approximately equal to the corresponding thresholds. B6C3F1 mice exposed to fractionated X-irradiation (Kaplan's method) followed by ENU developed T-cell lymphomas in a dose-dependent manner. Radiation doses above an apparent threshold acted synergistically with ENU to promote lymphoma development, whereas radiation doses below that threshold antagonized lymphoma development. Ikaros, which regulates the commitment and differentiation of lymphoid lineage cells, is a critical tumor suppressor gene frequently altered in both human and mouse lymphomas and shows distinct mutation spectra between X-ray- and ENU-induced lymphomas. In the synergistically induced lymphomas, we observed a low frequency of LOH and an inordinate increase of Ikaros base substitutions characteristic of ENU-indcued point mutations, G:C to A:T at non-CpG, A:T to G:C, G:C to T:A and A:T to T:A. This suggests that radiation doses above an apparent threshold activate the ENU mutagenic pathway. This is the first report on the carcinogenic mechanism elicited by combined exposure to carcinogens below and above threshold doses based on the mutation spectrum of the causative gene. These findings constitute a basis for assessing human cancer risk following exposure to multiple carcinogens.

  1. Learning and strategic asset allocation

    OpenAIRE

    Kearns, Michael

    2016-01-01

    This thesis investigates whether or not models that portray the relationship between what an investor learns and how he allocates his portfolio can explain phenomena related to household behaviour in the stock market. Endogenous modelling of household learning is utilised, which builds on a growing literature called bounded rationality with increasing explanatory power, offering an alternative to the classical rational expectations theory. Such phenomena include firstly why households often h...

  2. Resource allocation in networks via coalitional games

    NARCIS (Netherlands)

    Shams, F.

    2016-01-01

    The main goal of this dissertation is to manage resource allocation in network engineering problems and to introduce efficient cooperative algorithms to obtain high performance, ensuring fairness and stability. Specifically, this dissertation introduces new approaches for resource allocation in

  3. Asset Allocation of Mutual Fund Investors

    OpenAIRE

    Dengpan Luo

    2003-01-01

    This paper studies mutual fund investors' asset allocation decisions using monthly flow data of U.S mutual fund industry from 1984 to 1998. We find that mutual fund investors change their asset allocations between stocks and bonds in reaction to business conditions tracked by changes in expected stock market returns. They tend to allocate less into stock funds during the trough of a business cycle when expected stock market returns are higher and to allocate more into stock funds during the p...

  4. Optimal resource allocation for distributed video communication

    CERN Document Server

    He, Yifeng

    2013-01-01

    While most books on the subject focus on resource allocation in just one type of network, this book is the first to examine the common characteristics of multiple distributed video communication systems. Comprehensive and systematic, Optimal Resource Allocation for Distributed Video Communication presents a unified optimization framework for resource allocation across these systems. The book examines the techniques required for optimal resource allocation over Internet, wireless cellular networks, wireless ad hoc networks, and wireless sensor networks. It provides you with the required foundat

  5. Intelligent tactical asset allocation support system

    NARCIS (Netherlands)

    Hiemstra, Y.

    1995-01-01

    This paper presents an advanced support system for Tactical Asset Allocation. Asset allocation explains over 90% of portfolio performance (Brinson, Hood and Beebower, 1988). Tactical asset allocation adjusts a strategic portfolio on the basis of short term market outlooks. The system includes

  6. Energy-efficient dynamic resource allocation with energy harvesting nodes

    OpenAIRE

    Rubio López, Javier

    2012-01-01

    The allocation of radio resources where nodes are battery constrained. [ANGLÈS] In wireless communications, there is a trend to deploy shorter-distance networks to cope with the high demanding necessities of bit-rate that current applications require. In such networks, the power needed for transmission is considerably low, due to proximity between base station and mobile terminals. As a consequence, complex baseband algorithms for signal processing and radio frequency circuitry require an ...

  7. Practical Approaches to Adaptive Resource Allocation in OFDM Systems

    Directory of Open Access Journals (Sweden)

    N. Y. Ermolova

    2007-11-01

    Full Text Available Whenever a communication system operates in a time-frequency dispersive radio channel, the link adaptation provides a benefit in terms of any system performance metric by employing time, frequency, and, in case of multiple users, multiuser diversities. With respect to an orthogonal frequency division multiplexing (OFDM system, link adaptation includes bit, power, and subcarrier allocations. While the well-known water-filling principle provides the optimal solution for both margin-maximization and rate-maximization problems, implementation complexity often makes difficult its application in practical systems. This paper presents a few suboptimal (low-complexity adaptive loading algorithms for both single- and multiuser OFDM systems. We show that the single-user system performance can be improved by suitable power loading and an algorithm based on the incomplete channel state information is derived. At the same time, the power loading in a multiuser system only slightly affects performance while the initial subcarrier allocation has a rather big impact. A number of subcarrier allocation algorithms are discussed and the best one is derived on the basis of the order statistics theory.

  8. Frequency-Modulation Correlation Spectrometer

    Science.gov (United States)

    Margolis, J. S.; Martonchik, J. V.

    1985-01-01

    New type of correlation spectrometer eliminates need to shift between two cells, one empty and one containing reference gas. Electrooptical phase modulator sinusoidally shift frequencies of sample transmission spectrum.

  9. Tradable permit allocations and sequential choice

    Energy Technology Data Exchange (ETDEWEB)

    MacKenzie, Ian A. [Centre for Economic Research, ETH Zuerich, Zurichbergstrasse 18, 8092 Zuerich (Switzerland)

    2011-01-15

    This paper investigates initial allocation choices in an international tradable pollution permit market. For two sovereign governments, we compare allocation choices that are either simultaneously or sequentially announced. We show sequential allocation announcements result in higher (lower) aggregate emissions when announcements are strategic substitutes (complements). Whether allocation announcements are strategic substitutes or complements depends on the relationship between the follower's damage function and governments' abatement costs. When the marginal damage function is relatively steep (flat), allocation announcements are strategic substitutes (complements). For quadratic abatement costs and damages, sequential announcements provide a higher level of aggregate emissions. (author)

  10. Cost allocation review : staff discussion paper

    International Nuclear Information System (INIS)

    2005-09-01

    This report addressed the need for updated cost allocation studies filed by local electricity distribution companies because they ensure that distribution rates for each customer class remain just and reasonable. According to the 2001 Electricity Distribution Rate Handbook, the Ontario Energy Board requires new cost allocation studies before implementing any future incentive regulation plans. A review of cost allocations allows the Board to consider the need for adjustments to the current share of distribution costs paid by different classes of ratepayers. This report included 14 sections to facilitate consultations with stakeholders on financial information requirements for cost allocation; directly assignable costs; functionalization; categorization; allocation methods; allocation of other costs; load data requirements; cost allocation implementation issues; addition of new rate class and rate design for scattered unmetered loads; addition of new rate class for larger users; rates to charge embedded distributors; treatment of the rate sub-classification identified as time-of-use; and, rate design implementation issues. 1 fig., 7 appendices

  11. Market-driven spectrum sharing in cognitive radio

    CERN Document Server

    Yi, Changyan

    2016-01-01

    This brief focuses on the current research on mechanism design for dynamic spectrum sharing in cognitive radio (CR) networks. Along with a review of CR architectures and characteristics, this brief presents the motivations, significances and unique challenges of implementing algorithmic mechanism design for encouraging both primary spectrum owners and secondary spectrum users to participate in dynamic spectrum sharing. The brief then focuses on recent advances in mechanism design in CR networks. With an emphasis on dealing with the uncertain spectrum availabilities, mechanisms based on spectrum recall, two-stage spectrum sharing and online spectrum allocation are introduced with the support of theoretic analyses and numerical illustrations. The brief concludes with a discussion of potential research directions and interests, which will motivate further studies on mechanism design for wireless communications. This brief is concise and approachable for researchers, professionals and advanced-level students in w...

  12. Allocation decisions in network industries

    Energy Technology Data Exchange (ETDEWEB)

    Bolle, Friedel [Europa-Universitaet Viadrina Frankfurt, Lehrstuhl Volkswirtschaftslehre, insbesondere Wirtschaftstheorie (Mikrooekonomie), Postfach 1786 15207 Frankfurt (Germany)

    2008-01-15

    In this paper, I want to propagate a new analytical tool: The usage of Menu Auctions for modelling complicated auctions, negotiations, rent seeking, etc. is advocated, because, contrary to 'normal' auctions and bargaining models, an arbitrary number of additional aspects can be taken into account. After concentrating on 'Truthful Equilibria' [Bernheim, B.D., Whinston, M.D., 1986. Menu auctions, resource allocation, and economic influence, Quarterly Journal of Economics, 1-31.] a certain broad class of Menu Auctions show unique and efficient allocations. Under an additional concavity condition even the equilibrium bids are unique. Two examples are discussed: the privatisation of a state-owned industry and the buying of wholesale electricity (concluding contracts with a number of producers) by a utility. These examples also serve to trace the sources of 'non-concavities' which can prevent the uniqueness of bids and can provide the auctioneer with incentives to exclude bidders from the competition. (author)

  13. Allocation - the Howe measurement challenges

    Energy Technology Data Exchange (ETDEWEB)

    Tierney, Jim; Moksnes, Paul Ove

    2005-07-01

    The Howe Field is located in the Central North Sea Block 22/12a approximately 160 km east of Aberdeen in a water depth of 85 m. The reservoir lies some 12 km east of the Shell operated Nelson Platform, which is situated in adjacent Block 22/11. The Howe project was initiated by Shell Exploration and Production to augment the operating life and production capacity of the Nelson platform, involving the development of an additional subset infrastructure and the installation of topside facilities. The owners of the Howe Field are Enterprise Oil PLC , Intrepid Energy and OMV. The Howe well fluids are commingled with Nelson fluids. Therefore, it is required to measure the Howe well fluids to differentiate between the fields and to determine how much money each partner is allocated. The commercial agreements have stipulated that the measurements of Howe fluids are required to be measured within an accuracy of +- 5% of reading. In addition to accuracy constraints, it was important to minimise capex to ensure the development was economically viable. Given this, multiphase metering was considered to be a solution for allocation between the different ownerships, as opposed to traditional separator metering. This paper will present the journey of the project activity through the selection criteria, flow loop test, installation, commissioning and the first 3 months of operation of the MPFM including verification with the Nelson test separator. Detailing with careful management and engineering support how to succeed with this type of application. (author) (tk)

  14. Comparison of RF spectrum prediction methods for dynamic spectrum access

    Science.gov (United States)

    Kovarskiy, Jacob A.; Martone, Anthony F.; Gallagher, Kyle A.; Sherbondy, Kelly D.; Narayanan, Ram M.

    2017-05-01

    Dynamic spectrum access (DSA) refers to the adaptive utilization of today's busy electromagnetic spectrum. Cognitive radio/radar technologies require DSA to intelligently transmit and receive information in changing environments. Predicting radio frequency (RF) activity reduces sensing time and energy consumption for identifying usable spectrum. Typical spectrum prediction methods involve modeling spectral statistics with Hidden Markov Models (HMM) or various neural network structures. HMMs describe the time-varying state probabilities of Markov processes as a dynamic Bayesian network. Neural Networks model biological brain neuron connections to perform a wide range of complex and often non-linear computations. This work compares HMM, Multilayer Perceptron (MLP), and Recurrent Neural Network (RNN) algorithms and their ability to perform RF channel state prediction. Monte Carlo simulations on both measured and simulated spectrum data evaluate the performance of these algorithms. Generalizing spectrum occupancy as an alternating renewal process allows Poisson random variables to generate simulated data while energy detection determines the occupancy state of measured RF spectrum data for testing. The results suggest that neural networks achieve better prediction accuracy and prove more adaptable to changing spectral statistics than HMMs given sufficient training data.

  15. Ambiguities in the deduction of rest frame fluctuation spectrums from spectrums computed in moving frames

    International Nuclear Information System (INIS)

    Fredericks, R.W.; Coroniti, F.V.

    1976-01-01

    The problem of interpretation of power spectrums computed by Fourier analysis of data time series taken in frames moving with respect to the medium containing the fluctuations is examined. It is found that no unique connection exists between the rest frame power spectrum as a function of scale length and the derived power spectrum as a function 'frequency' computed from the time series data taken in the moving frame. This caused by a complex Doppler-shifting phenomenon that leads to a basically aliased frequency spectrum in the moving frame. Examples of nonuniqueness are given for various types of rest frame density or wave turbulence that lead to the same frequency dependence of the power spectrum computed in the moving frame. This has implications for the past interpretations of power spectrums of density or magnetic field fluctuations from satellites or interplanetary probes

  16. Atypical resource allocation may contribute to many aspects of autism

    Directory of Open Access Journals (Sweden)

    Emily J. Goldknopf

    2013-12-01

    Full Text Available Based on a review of the literature and on reports by people with autism, this paper suggests that atypical resource allocation is a factor that contributes to many aspects of autism spectrum conditions, including difficulties with language and social cognition, atypical sensory and attentional experiences, executive and motor challenges, and perceptual and conceptual strengths and weaknesses. Drawing upon resource theoretical approaches that suggest that perception, cognition, and action draw upon multiple pools of resources, the approach states that compared with resources in typical cognition, resources in autism are narrowed or reduced, especially in people with strong sensory symptoms. In narrowed attention, resources are restricted to smaller areas and to fewer modalities, stages of processing, and cognitive processes than in typical cognition; resources may be more intense than in typical cognition. In reduced attentional capacity, overall resources are reduced; resources may be restricted to fewer modalities, stages of processing, and cognitive processes than in typical cognition, or the amount of resources allocated to each area or process may be reduced. Possible neural bases of the hypothesized atypical resource allocation, relations to other approaches, limitations, and tests of the hypotheses are discussed.

  17. Dynamic Resource Allocation in Hybrid Access Femtocell Network

    Directory of Open Access Journals (Sweden)

    Afaz Uddin Ahmed

    2014-01-01

    Full Text Available Intercell interference is one of the most challenging issues in femtocell deployment under the coverage of existing macrocell. Allocation of resources between femtocell and macrocell is essential to counter the effects of interference in dense femtocell networks. Advances in resource management strategies have improved the control mechanism for interference reduction at lower node density, but most of them are ineffective at higher node density. In this paper, a dynamic resource allocation management algorithm (DRAMA for spectrum shared hybrid access OFDMA femtocell network is proposed. To reduce the macro-femto-tier interference and to improve the quality of service, the proposed algorithm features a dynamic resource allocation scheme by controlling them both centrally and locally. The proposed scheme focuses on Femtocell Access Point (FAP owners’ satisfaction and allows maximum utilization of available resources based on congestion in the network. A simulation environment is developed to study the quantitative performance of DRAMA in hybrid access-control femtocell network and compare it to closed and open access mechanisms. The performance analysis shows that higher number of random users gets connected to the FAP without compromising FAP owners’ satisfaction allowing the macrocell to offload a large number of users in a dense heterogeneous network.

  18. NASH BARGAINING BASED BANDWIDTH ALLOCATION IN COGNITIVE RADIO FOR DELAY CRITICAL APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Kalyani Kulkarni

    2015-11-01

    Full Text Available In order to effectively regulate the existing resources, dynamic spectrum access in cognitive radio needs to adopt the effective resource allocation strategies. Multimedia applications require large bandwidth and have to meet the delay constraints while maintaining the data quality. Game theory is emerging as an effective analytical tool for the analysis of available resources and its allocation. This paper addresses resource allocation schemes employing bargaining game model for Multi-carrier CDMA based Cognitive Radio. Resource allocation scheme is designed for transmission of video over cognitive radio networks and aim to perform bandwidth allocation for different cognitive users. Utility function based on bargaining model is proposed. Primary user utility function includes the pricing factor and an upbeat factor that can be adjusted by observing the delay constraints of the video. Allocated bandwidth to the secondary user can be adjusted by changing the upbeat factor. Throughput in the proposed scheme is increased by 2% as compared to other reported pricing based resource allocation schemes. The edge PSNR of reconstructed video obtained as 32.6dB resulting to optimum decoding of the video at the receiver. The study also shows upbeat factor can be used to enhanced capacity of the network.

  19. Transmission usage cost allocation schemes

    International Nuclear Information System (INIS)

    Abou El Ela, A.A.; El-Sehiemy, R.A.

    2009-01-01

    This paper presents different suggested transmission usage cost allocation (TCA) schemes to the system individuals. Different independent system operator (ISO) visions are presented using the proportional rata and flow-based TCA methods. There are two proposed flow-based TCA schemes (FTCA). The first FTCA scheme generalizes the equivalent bilateral exchanges (EBE) concepts for lossy networks through two-stage procedure. The second FTCA scheme is based on the modified sensitivity factors (MSF). These factors are developed from the actual measurements of power flows in transmission lines and the power injections at different buses. The proposed schemes exhibit desirable apportioning properties and are easy to implement and understand. Case studies for different loading conditions are carried out to show the capability of the proposed schemes for solving the TCA problem. (author)

  20. An investigation of dynamic subcarrier allocation in MIMO–OFDMA systems

    OpenAIRE

    Peng, Y; Armour, SMD; McGeehan, JP

    2007-01-01

    In this paper, orthogonal frequency-division multiple-access (OFDMA) systems with dynamic deterministic (as opposed to pseudorandom) allocation of subcarriers to users to exploit multiuser diversity are investigated. Previously published work on dynamic multiuser subcarrrier allocation for OFDMA systems with single-input-single-output (SISO) channels are surveyed. A near-optimal low-complexity algorithm for SISO systems, which is structurally similar to the algorithm by Rhee and Cioffi, is ex...

  1. Channel Estimation and Optimal Power Allocation for a Multiple-Antenna OFDM System

    Directory of Open Access Journals (Sweden)

    Yao Kung

    2002-01-01

    Full Text Available We propose combining channel estimation and optimal power allocation approaches for a multiple-antenna orthogonal frequency division multiplexing (OFDM system in high-speed transmission applications. We develop a least-square channel estimation approach, derive the performance bound of the estimator, and investigate the optimal training sequences for initial channel acquisition. Based on the channel estimates, the optimal power allocation solution which maximizes the bandwidth efficiency is derived under power and quality of service (Qos (symbol error rate constraints. It is shown that combining channel tracking and adaptive power allocation can dramatically enhance the outage capacity of an OFDM multiple-antenna system when severing fading occurs.

  2. Low Frequency Space Array

    International Nuclear Information System (INIS)

    Dennison, B.; Weiler, K.W.; Johnston, K.J.

    1987-01-01

    The Low Frequency Space Array (LFSA) is a conceptual mission to survey the entire sky and to image individual sources at frequencies between 1.5 and 26 MHz, a frequency range over which the earth's ionosphere transmits poorly or not at all. With high resolution, high sensitivity observations, a new window will be opened in the electromagnetic spectrum for astronomical investigation. Also, extending observations down to such low frequencies will bring astronomy to the fundamental limit below which the galaxy becomes optically thick due to free-free absorption. A number of major scientific goals can be pursued with such a mission, including mapping galactic emission and absorption, studies of individual source spectra in a frequency range where a number of important processes may play a role, high resolution imaging of extended sources, localization of the impulsive emission from Jupiter, and a search for coherent emission processes. 19 references

  3. Intelligent tactical asset allocation support system

    OpenAIRE

    Hiemstra, Y.

    1995-01-01

    This paper presents an advanced support system for Tactical Asset Allocation. Asset allocation explains over 90% of portfolio performance (Brinson, Hood and Beebower, 1988). Tactical asset allocation adjusts a strategic portfolio on the basis of short term market outlooks. The system includes aprediction model that forecasts quarterly excess returns on the S and PSOO, an optimization model that adjusts a user-specified strategic portfolio on thebasis of the excess return forecast, and a compo...

  4. Optimal resource allocation solutions for heterogeneous cognitive radio networks

    Directory of Open Access Journals (Sweden)

    Babatunde Awoyemi

    2017-05-01

    Full Text Available Cognitive radio networks (CRN are currently gaining immense recognition as the most-likely next-generation wireless communication paradigm, because of their enticing promise of mitigating the spectrum scarcity and/or underutilisation challenge. Indisputably, for this promise to ever materialise, CRN must of necessity devise appropriate mechanisms to judiciously allocate their rather scarce or limited resources (spectrum and others among their numerous users. ‘Resource allocation (RA in CRN', which essentially describes mechanisms that can effectively and optimally carry out such allocation, so as to achieve the utmost for the network, has therefore recently become an important research focus. However, in most research works on RA in CRN, a highly significant factor that describes a more realistic and practical consideration of CRN has been ignored (or only partially explored, i.e., the aspect of the heterogeneity of CRN. To address this important aspect, in this paper, RA models that incorporate the most essential concepts of heterogeneity, as applicable to CRN, are developed and the imports of such inclusion in the overall networking are investigated. Furthermore, to fully explore the relevance and implications of the various heterogeneous classifications to the RA formulations, weights are attached to the different classes and their effects on the network performance are studied. In solving the developed complex RA problems for heterogeneous CRN, a solution approach that examines and exploits the structure of the problem in achieving a less-complex reformulation, is extensively employed. This approach, as the results presented show, makes it possible to obtain optimal solutions to the rather difficult RA problems of heterogeneous CRN.

  5. An intelligent allocation algorithm for parallel processing

    Science.gov (United States)

    Carroll, Chester C.; Homaifar, Abdollah; Ananthram, Kishan G.

    1988-01-01

    The problem of allocating nodes of a program graph to processors in a parallel processing architecture is considered. The algorithm is based on critical path analysis, some allocation heuristics, and the execution granularity of nodes in a program graph. These factors, and the structure of interprocessor communication network, influence the allocation. To achieve realistic estimations of the executive durations of allocations, the algorithm considers the fact that nodes in a program graph have to communicate through varying numbers of tokens. Coarse and fine granularities have been implemented, with interprocessor token-communication duration, varying from zero up to values comparable to the execution durations of individual nodes. The effect on allocation of communication network structures is demonstrated by performing allocations for crossbar (non-blocking) and star (blocking) networks. The algorithm assumes the availability of as many processors as it needs for the optimal allocation of any program graph. Hence, the focus of allocation has been on varying token-communication durations rather than varying the number of processors. The algorithm always utilizes as many processors as necessary for the optimal allocation of any program graph, depending upon granularity and characteristics of the interprocessor communication network.

  6. Cognitive radio networks dynamic resource allocation schemes

    CERN Document Server

    Wang, Shaowei

    2014-01-01

    This SpringerBrief presents a survey of dynamic resource allocation schemes in Cognitive Radio (CR) Systems, focusing on the spectral-efficiency and energy-efficiency in wireless networks. It also introduces a variety of dynamic resource allocation schemes for CR networks and provides a concise introduction of the landscape of CR technology. The author covers in detail the dynamic resource allocation problem for the motivations and challenges in CR systems. The Spectral- and Energy-Efficient resource allocation schemes are comprehensively investigated, including new insights into the trade-off

  7. 47 CFR 18.301 - Operating frequencies.

    Science.gov (United States)

    2010-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL INDUSTRIAL, SCIENTIFIC, AND MEDICAL EQUIPMENT Technical... as indicated in § 18.303. The following frequency bands, in accordance with § 2.106 of the rules, are... ±15 kHz frequency band is subject to the conditions of footnote 524 of the Table of Allocations. See...

  8. Economic versus technical approaches to frequency management

    DEFF Research Database (Denmark)

    Falch, Morten; Tadayoni, Reza

    2004-01-01

    to demonstrate how regulators could incorporate an econmic dimension into frequency allocation. The paper concludes that a free market approach is still not possible for some parts of the frequency management process; in short term, regulators must therefore continue to prioritize between applications....

  9. Peer-Allocated Instant Response (PAIR): Computional allocation of peer tutors in learning communities

    NARCIS (Netherlands)

    Westera, Wim

    2009-01-01

    Westera, W. (2007). Peer-Allocated Instant Response (PAIR): Computational allocation of peer tutors in learning communities. Journal of Artificial Societies and Social Simulation, http://jasss.soc.surrey.ac.uk/10/2/5.html

  10. Time allocation of disabled individuals.

    Science.gov (United States)

    Pagán, Ricardo

    2013-05-01

    Although some studies have analysed the disability phenomenon and its effect on, for example, labour force participation, wages, job satisfaction, or the use of disability pension, the empirical evidence on how disability steals time (e.g. hours of work) from individuals is very scarce. This article examines how disabled individuals allocate their time to daily activities as compared to their non-disabled counterparts. Using time diary information from the Spanish Time Use Survey (last quarter of 2002 and the first three quarters of 2003), we estimate the determinants of time (minutes per day) spent on four aggregate categories (market work, household production, tertiary activities and leisure) for a sample of 27,687 non-disabled and 5250 disabled individuals and decompose the observed time differential by using the Oaxaca-Blinder methodology. The results show that disabled individuals devote less time to market work (especially females), and more time to household production (e.g. cooking, cleaning, child care), tertiary activities (e.g., sleeping, personal care, medical treatment) and leisure activities. We also find a significant effect of age on the time spent on daily activities and important differences by gender and disability status. The results are consistent with the hypothesis that disability steals time, and reiterate the fact that more public policies are needed to balance working life and health concerns among disabled individuals. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Multiobjective optimal allocation problem with probabilistic non ...

    African Journals Online (AJOL)

    user

    In multivariate stratified sampling where more than one characteristic are to be estimated, an allocation which is optimum for one characteristic may not be optimum for other characteristics also. In such situations a compromise criterion is needed to work out a usable allocation which is optimum for all characteristics in some ...

  12. Bounds in the location-allocation problem

    DEFF Research Database (Denmark)

    Juel, Henrik

    1981-01-01

    Develops a family of stronger lower bounds on the objective function value of the location-allocation problem. Solution methods proposed to solve problems in location-allocation; Efforts to develop a more efficient bound solution procedure; Determination of the locations of the sources....

  13. A Time Allocation Study of University Faculty

    Science.gov (United States)

    Link, Albert N.; Swann, Christopher A.; Bozeman, Barry

    2008-01-01

    Many previous time allocation studies treat work as a single activity and examine trade-offs between work and other activities. This paper investigates the at-work allocation of time among teaching, research, grant writing and service by science and engineering faculty at top US research universities. We focus on the relationship between tenure…

  14. Obtaining a Proportional Allocation by Deleting Items

    NARCIS (Netherlands)

    Dorn, B.; de Haan, R.; Schlotter, I.; Röthe, J.

    2017-01-01

    We consider the following control problem on fair allocation of indivisible goods. Given a set I of items and a set of agents, each having strict linear preference over the items, we ask for a minimum subset of the items whose deletion guarantees the existence of a proportional allocation in the

  15. Directed networks, allocation properties and hierarchy formation

    NARCIS (Netherlands)

    Slikker, M.; Gilles, R.P.; Norde, H.W.; Tijs, S.H.

    2005-01-01

    We investigate properties for allocation rules on directed communication networks and the formation of such networks under these payoff properties. We study allocation rules satisfying two appealing properties, Component Efficiency (CE) and the Hierarchical Payoff Property (HPP). We show that such

  16. Nash social welfare in multiagent resource allocation

    NARCIS (Netherlands)

    Ramezani, S.; Endriss, U.; David, E.; Gerding, E.; Sarne, D.; Shehory, O.

    2010-01-01

    We study different aspects of the multiagent resource allocation problem when the objective is to find an allocation that maximizes Nash social welfare, the product of the utilities of the individual agents. The Nash solution is an important welfare criterion that combines efficiency and fairness

  17. Risk and reliability allocation to risk control

    International Nuclear Information System (INIS)

    Vojnovic, D.; Kozuh, M.

    1992-01-01

    The risk allocation procedure is used as an analytical model to support the optimal decision making for reliability/availability improvement planning. Both levels of decision criteria, the plant risk measures and plant performance indices, are used in risk allocation procedure. Decision support system uses the multi objective decision making concept. (author) [sl

  18. Bidding for surplus in network allocation problems

    NARCIS (Netherlands)

    Slikker, M.

    2007-01-01

    In this paper we study non-cooperative foundations of network allocation rules. We focus on three allocation rules: the Myerson value, the position value and the component-wise egalitarian solution. For any of these three rules we provide a characterization based on component efficiency and some

  19. Cost Allocation and Convex Data Envelopment

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Tind, Jørgen

    such as Data Envelopment Analysis (DEA). The convexity constraint of the BCC model introduces a non-zero slack in the objective function of the multiplier problem and we show that the cost allocation rules discussed in this paper can be used as candidates to allocate this slack value on to the input (or output...

  20. Optimal allocation of resources in systems

    International Nuclear Information System (INIS)

    Derman, C.; Lieberman, G.J.; Ross, S.M.

    1975-01-01

    In the design of a new system, or the maintenance of an old system, allocation of resources is of prime consideration. In allocating resources it is often beneficial to develop a solution that yields an optimal value of the system measure of desirability. In the context of the problems considered in this paper the resources to be allocated are components already produced (assembly problems) and money (allocation in the construction or repair of systems). The measure of desirability for system assembly will usually be maximizing the expected number of systems that perform satisfactorily and the measure in the allocation context will be maximizing the system reliability. Results are presented for these two types of general problems in both a sequential (when appropriate) and non-sequential context

  1. Relay selection and resource allocation for two-way DF-AF cognitive radio networks

    KAUST Repository

    Alsharoa, Ahmad M.; Bader, Faouzi; Alouini, Mohamed-Slim

    2013-01-01

    In this letter, the problem of relay selection and optimal resource allocation for two-way relaying cognitive radio networks using half duplex amplify-and-forward and decode-and-forward protocols is investigated. The primary and secondary users are assumed to access the spectrum simultaneously, in a way that the interference introduced to the primary users should be below a certain tolerated limit. Dual decomposition and subgradient methods are used to find the optimal power allocation. A suboptimal approach based on a genetic algorithm is also presented. Simulation results show that the proposed suboptimal algorithm offers a performance close to the optimal performance with a considerable complexity saving. © 2013 IEEE.

  2. Relay selection and resource allocation for two-way DF-AF cognitive radio networks

    KAUST Repository

    Alsharoa, Ahmad M.

    2013-08-01

    In this letter, the problem of relay selection and optimal resource allocation for two-way relaying cognitive radio networks using half duplex amplify-and-forward and decode-and-forward protocols is investigated. The primary and secondary users are assumed to access the spectrum simultaneously, in a way that the interference introduced to the primary users should be below a certain tolerated limit. Dual decomposition and subgradient methods are used to find the optimal power allocation. A suboptimal approach based on a genetic algorithm is also presented. Simulation results show that the proposed suboptimal algorithm offers a performance close to the optimal performance with a considerable complexity saving. © 2013 IEEE.

  3. Cognitive Spectrum Efficient Multiple Access Technique using Relay Systems

    DEFF Research Database (Denmark)

    Frederiksen, Flemming Bjerge; Prasad, Ramjee

    2007-01-01

    Methods to enhance the use of the frequency spectrum by automatical spectrum sensing plus spectrum sharing in a cognitive radio technology context will be presented and discussed in this paper. Ideas to increase the coverage of cellular systems by relay channels, relay stations and collaborate...

  4. Reducing LTE Uplink Transmission Energy by Allocating Resources

    DEFF Research Database (Denmark)

    Lauridsen, Mads; Jensen, Anders Riis; Mogensen, Preben

    2011-01-01

    The effect of physical resource block (PRB) allocation on an LTE modem's transmit power and total modem energy consumption is examined. In this paper the uplink resource blocks are scheduled in either a Frequency Division Multiple Access (FDMA) or Time Division Multiple Access (TDMA) manner......, to determine if low transmission power & long transmission time or high transmission power & short transmission time is most energy efficient. It is important to minimize the LTE modem's energy consumption caused by uplink transmission because it affects phone battery time, and because researchers rarely focus...

  5. Experimental demonstration of spectrum-sliced elastic optical path network (SLICE).

    Science.gov (United States)

    Kozicki, Bartłomiej; Takara, Hidehiko; Tsukishima, Yukio; Yoshimatsu, Toshihide; Yonenaga, Kazushige; Jinno, Masahiko

    2010-10-11

    We describe experimental demonstration of spectrum-sliced elastic optical path network (SLICE) architecture. We employ optical orthogonal frequency-division multiplexing (OFDM) modulation format and bandwidth-variable optical cross-connects (OXC) to generate, transmit and receive optical paths with bandwidths of up to 1 Tb/s. We experimentally demonstrate elastic optical path setup and spectrally-efficient transmission of multiple channels with bit rates ranging from 40 to 140 Gb/s between six nodes of a mesh network. We show dynamic bandwidth scalability for optical paths with bit rates of 40 to 440 Gb/s. Moreover, we demonstrate multihop transmission of a 1 Tb/s optical path over 400 km of standard single-mode fiber (SMF). Finally, we investigate the filtering properties and the required guard band width for spectrally-efficient allocation of optical paths in SLICE.

  6. Application of genetic algorithm for reliability allocation in nuclear power plants

    International Nuclear Information System (INIS)

    Yang, Joon-Eon; Hwang, Mee-Jung; Sung, Tae-Yong; Jin, Youngho

    1999-01-01

    Reliability allocation is an optimization process of minimizing the total plant costs subject to the overall plant safety goal constraints. Reliability allocation was applied to determine the reliability characteristics of reactor systems, subsystems, major components and plant procedures that are consistent with a set of top-level performance goals; the core melt frequency, acute fatalities and latent fatalities. Reliability allocation can be performed to improve the design, operation and safety of new and/or existing nuclear power plants. Reliability allocation is a kind of a difficult multi-objective optimization problem as well as a global optimization problem. The genetic algorithm, known as one of the most powerful tools for most optimization problems, is applied to the reliability allocation problem of a typical pressurized water reactor in this article. One of the main problems of reliability allocation is defining realistic objective functions. Hence, in order to optimize the reliability of the system, the cost for improving and/or degrading the reliability of the system should be included in the reliability allocation process. We used techniques derived from the value impact analysis to define the realistic objective function in this article

  7. Identifying Memory Allocation Patterns in HEP Software

    Science.gov (United States)

    Kama, S.; Rauschmayr, N.

    2017-10-01

    HEP applications perform an excessive amount of allocations/deallocations within short time intervals which results in memory churn, poor locality and performance degradation. These issues are already known for a decade, but due to the complexity of software frameworks and billions of allocations for a single job, up until recently no efficient mechanism has been available to correlate these issues with source code lines. However, with the advent of the Big Data era, many tools and platforms are now available to do large scale memory profiling. This paper presents, a prototype program developed to track and identify each single (de-)allocation. The CERN IT Hadoop cluster is used to compute memory key metrics, like locality, variation, lifetime and density of allocations. The prototype further provides a web based visualization back-end that allows the user to explore the results generated on the Hadoop cluster. Plotting these metrics for every single allocation over time gives a new insight into application’s memory handling. For instance, it shows which algorithms cause which kind of memory allocation patterns, which function flow causes how many short-lived objects, what are the most commonly allocated sizes etc. The paper will give an insight into the prototype and will show profiling examples for the LHC reconstruction, digitization and simulation jobs.

  8. Clinical spectrum of onchodermatitis

    International Nuclear Information System (INIS)

    Bari, A.U.

    2007-01-01

    To describe the frequency and to see various dermatological presentations of onchocerciasis in black Africans of Sierra Leone. Local black patients of all age groups, attending dermatology outpatient department of Pak Field Hospital (established as a part of UN peacekeeping mission in Sierra Leone) with clinical diagnosis of onchodermatitis, based on symptomatology and morphological features of the disease, were included. UN troops were excluded. Laboratory investigations including blood complete picture and skin snips were carried out in all patients. Skin biopsy and nodule biopsy was performed in selected cases. Skin manifestations were recorded and categorized into various clinical patterns, i.e. acute, chronic, lichenified, onchocercoma, etc. Data was analyzed by using descriptive statistics in Instat. A total of 3011 patients, belonging to different local tribes, having a variety of skin disorders, were seen during the study period. One hundred and eighty-seven (6.2%) patients were found to have onchodermatitis. Patients were of all ages and both sexes, their ages ranging from 1 month to 73 years. Gender ratio was almost equal. A whole clinical spectrum of onchodermatitis was observed, chronic papular onchodermatitis being the most common pattern. Onchodermatitis with a large spectrum of clinical manifestations was seen in black Africans of the eastern part of Sierra Leone. (author)

  9. A new reliability allocation weight for reducing the occurrence of severe failure effects

    International Nuclear Information System (INIS)

    Kim, Kyungmee O.; Yang, Yoonjung; Zuo, Ming J.

    2013-01-01

    A reliability allocation weight is used during the early design stage of a system to apportion the system reliability requirement to its individual subsystems. Since some failures have serious effects on public safety, cost and environmental issues especially in a mission critical system, the failure effect must be considered as one of the important factors in determining the allocation weight. Previously, the risk priority number or the criticality number was used to consider the failure effect in the allocation weight. In this paper, we identify the limitations of the previous approach and propose a new allocation weight based on the subsystem failure severity and its relative frequency. An example is given to illustrate that the proposed method is more effective than the previous method for reducing the occurrence of the unacceptable failure effects in a newly designed system

  10. Worst-case analysis of heap allocations

    DEFF Research Database (Denmark)

    Puffitsch, Wolfgang; Huber, Benedikt; Schoeberl, Martin

    2010-01-01

    the worst-case heap allocations of tasks. The analysis builds upon techniques that are well established for worst-case execution time analysis. The difference is that the cost function is not the execution time of instructions in clock cycles, but the allocation in bytes. In contrast to worst-case execution...... time analysis, worst-case heap allocation analysis is not processor dependent. However, the cost function depends on the object layout of the runtime system. The analysis is evaluated with several real-time benchmarks to establish the usefulness of the analysis, and to compare the memory consumption...

  11. Dynamic Allocation of Sugars in Barley

    Science.gov (United States)

    Cumberbatch, L. C.; Crowell, A. S.; Fallin, B. A.; Howell, C. R.; Reid, C. D.; Weisenberger, A. G.; Lee, S. J.; McKisson, J. E.

    2014-03-01

    Allocation of carbon and nitrogen is a key factor for plant productivity. Measurements are carried out by tracing 11C-tagged sugars using positron emission tomography and coincidence counting. We study the mechanisms of carbon allocation and transport from carbohydrate sources (leaves) to sinks (stem, shoot, roots) under various environmental conditions such as soil nutrient levels and atmospheric CO2 concentration. The data are analyzed using a transfer function analysis technique to model transport and allocation in barley plants. The experimental technique will be described and preliminary results presented. This work was supported in part by USDOE Grant No. DE-FG02-97-ER41033 and DE-SC0005057.

  12. Width of electromagnetic wave instability spectrum in tungsten plate

    International Nuclear Information System (INIS)

    Rinkevich, A.B.

    1995-01-01

    Based on the study of high-frequency signal modulation and spectrum analysis of the envelope a measurement of spectrum width for electromagnetic wave instability was carried out under conditions of current pulse action on tungsten plate in magnetic field. The existence of amplitude-frequency wave modulation was revealed. The width of current disturbance spectrum in a specimen was evaluated. Current disturbances are shown to cause the instability of electromagnetic wave. 11 refs.; 6 figs

  13. A Novel Wireless Power Transfer-Based Weighed Clustering Cooperative Spectrum Sensing Method for Cognitive Sensor Networks.

    Science.gov (United States)

    Liu, Xin

    2015-10-30

    In a cognitive sensor network (CSN), the wastage of sensing time and energy is a challenge to cooperative spectrum sensing, when the number of cooperative cognitive nodes (CNs) becomes very large. In this paper, a novel wireless power transfer (WPT)-based weighed clustering cooperative spectrum sensing model is proposed, which divides all the CNs into several clusters, and then selects the most favorable CNs as the cluster heads and allows the common CNs to transfer the received radio frequency (RF) energy of the primary node (PN) to the cluster heads, in order to supply the electrical energy needed for sensing and cooperation. A joint resource optimization is formulated to maximize the spectrum access probability of the CSN, through jointly allocating sensing time and clustering number. According to the resource optimization results, a clustering algorithm is proposed. The simulation results have shown that compared to the traditional model, the cluster heads of the proposed model can achieve more transmission power and there exists optimal sensing time and clustering number to maximize the spectrum access probability.

  14. A Novel Wireless Power Transfer-Based Weighed Clustering Cooperative Spectrum Sensing Method for Cognitive Sensor Networks

    Directory of Open Access Journals (Sweden)

    Xin Liu

    2015-10-01

    Full Text Available In a cognitive sensor network (CSN, the wastage of sensing time and energy is a challenge to cooperative spectrum sensing, when the number of cooperative cognitive nodes (CNs becomes very large. In this paper, a novel wireless power transfer (WPT-based weighed clustering cooperative spectrum sensing model is proposed, which divides all the CNs into several clusters, and then selects the most favorable CNs as the cluster heads and allows the common CNs to transfer the received radio frequency (RF energy of the primary node (PN to the cluster heads, in order to supply the electrical energy needed for sensing and cooperation. A joint resource optimization is formulated to maximize the spectrum access probability of the CSN, through jointly allocating sensing time and clustering number. According to the resource optimization results, a clustering algorithm is proposed. The simulation results have shown that compared to the traditional model, the cluster heads of the proposed model can achieve more transmission power and there exists optimal sensing time and clustering number to maximize the spectrum access probability.

  15. Spectrum monitoring procedures and techniques

    Science.gov (United States)

    1990-07-01

    The first step towards operating an emitter on a test range is to contact the local frequency manager to establish a schedule. Since restricted radio frequency bands and operations are different at each test range location, most testing is accomplished by sharing the spectrum available with all range users. The telemetry bands in particular require spectrum activity scheduling. The objective is to resolve scheduling conflicts prior to operations. When two programs or projects request to use the same spectrum, their activity can be separated by quard bands, discrete frequencies, time, or operating locations (terrain masking). Priorities assigned to each program usually dictate which program will be scheduled first; however, use of priorities to schedule activities should be avoided and only considered as a last resort. When a scheduling conflict cannot be resolved using these techniques, it is brought to the attention of the responsible program managers. When scheduling activities involve other federal or nonfederal agencies, it is in the best interest of program managers to be as flexible as possible.

  16. Low-frequency noise in planar Hall effect bridge sensors

    DEFF Research Database (Denmark)

    Persson, Anders; Bejhedb, R.S.; Bejhed, R.S.

    2011-01-01

    The low-frequency characteristics of planar Hall effect bridge sensors are investigated as function of the sensor bias current and the applied magnetic field. The noise spectra reveal a Johnson-like spectrum at high frequencies, and a 1/f-like excess noise spectrum at lower frequencies, with a kn...

  17. Attentional Shifts between Audition and Vision in Autism Spectrum Disorders

    Science.gov (United States)

    Occelli, Valeria; Esposito, Gianluca; Venuti, Paola; Arduino, Giuseppe Maurizio; Zampini, Massimiliano

    2013-01-01

    Previous evidence on neurotypical adults shows that the presentation of a stimulus allocates the attention to its modality, resulting in faster responses to a subsequent target presented in the same (vs. different) modality. People with Autism Spectrum Disorders (ASDs) often fail to detect a (visual or auditory) target in a stream of stimuli after…

  18. ALLOCATION OF FINANCIAL RESOURCE TO ENHANCE ...

    African Journals Online (AJOL)

    GRACE

    This study examines the allocation of financial resource to the education industry and ..... This should check all books of account at least once a month to reconcile ... All cash advance request must be supported with relevant documents vii.

  19. Fund allocation using capacitated vehicle routing problem

    Science.gov (United States)

    Mamat, Nur Jumaadzan Zaleha; Jaaman, Saiful Hafizah; Ahmad, Rokiah Rozita; Darus, Maslina

    2014-09-01

    In investment fund allocation, it is unwise for an investor to distribute his fund into several assets simultaneously due to economic reasons. One solution is to allocate the fund into a particular asset at a time in a sequence that will either maximize returns or minimize risks depending on the investor's objective. The vehicle routing problem (VRP) provides an avenue to this issue. VRP answers the question on how to efficiently use the available fleet of vehicles to meet a given service demand, subjected to a set of operational requirements. This paper proposes an idea of using capacitated vehicle routing problem (CVRP) to optimize investment fund allocation by employing data of selected stocks in the FTSE Bursa Malaysia. Results suggest that CRVP can be applied to solve the issue of investment fund allocation and increase the investor's profit.

  20. U.S. Army Recruiter Allocation Model

    National Research Council Canada - National Science Library

    Brence, John

    2004-01-01

    .... Our methodology will build on both the new and old schools of recruiting by conducting stakeholder interviews that will lead us to a model that is an efficient starting point for the Recruiter Mission Allocation (RMA...

  1. Optimal Resource Allocation in Library Systems

    Science.gov (United States)

    Rouse, William B.

    1975-01-01

    Queueing theory is used to model processes as either waiting or balking processes. The optimal allocation of resources to these processes is defined as that which maximizes the expected value of the decision-maker's utility function. (Author)

  2. Resource allocation based on cost efficiency

    DEFF Research Database (Denmark)

    Dehnokhalaji, Akram; Ghiyasi, Mojtaba; Korhonen, Pekka

    2017-01-01

    -objective linear programming problem using two different strategies. First, we propose an RA model which keeps the cost efficiencies of units unchanged. This is done assuming fixed technical and allocative efficiencies. The approach is based on the assumption that the decision maker (DM) may not have big changes......In this paper, we consider a resource allocation (RA) problem and develop an approach based on cost (overall) efficiency. The aim is to allocate some inputs among decision making units (DMUs) in such way that their cost efficiencies improve or stay unchanged after RA. We formulate a multi...... in the structure of DMUs within a short term. The second strategy does not impose any restrictions on technical and allocative efficiencies. It guarantees that none of the cost efficiencies of DMUs get worse after RA, and the improvement for units is possible if it is feasible and beneficial. Two numerical...

  3. regional grain allocation and transportation in China

    African Journals Online (AJOL)

    use

    2011-12-14

    Dec 14, 2011 ... China was partitioned into eight regions, and the virtual water flow due to regional grain allocation and ... strategy can be choices which can realize Chinese food security and ..... Globalization of water: Sharing the planet's ...

  4. Telecommunications Circuit Allocation Programs - Kansas City Area

    National Research Council Canada - National Science Library

    Thomas, William

    1994-01-01

    The overall objective of the audit was to determine whether DoD circuit allocation programs identified and used the most effective configurations for leased long-haul, special-purpose telecommunications circuits...

  5. Energy-Efficient Power Allocation for UAV Cognitive Radio Systems

    KAUST Repository

    Sboui, Lokman

    2018-02-12

    We study the deployment of unmanned aerial vehicles (UAV) based cognitive system in an area covered by the primary network (PN). An UAV shares the spectrum of the PN and aims to maximize its energy efficiency (EE) by optimizing the transmit power. We focus on the case where the UAV simultaneously communicates with the ground receiver (G), under interference limitation, and with another relaying UAV (A), with a minimal required rate. We analytically develop the power allocation framework that maximizes the EE subject to power budget, interference, and minimal rate constraints. In the numerical results, we show that the minimal rate may cause a transmission outage at low power budget values. We also highlighted the existence of optimal altitudes given the UAV location with respect to the different other terminals.

  6. Energy-Efficient Power Allocation for UAV Cognitive Radio Systems

    KAUST Repository

    Sboui, Lokman; Ghazzai, Hakim; Rezki, Zouheir; Alouini, Mohamed-Slim

    2018-01-01

    We study the deployment of unmanned aerial vehicles (UAV) based cognitive system in an area covered by the primary network (PN). An UAV shares the spectrum of the PN and aims to maximize its energy efficiency (EE) by optimizing the transmit power. We focus on the case where the UAV simultaneously communicates with the ground receiver (G), under interference limitation, and with another relaying UAV (A), with a minimal required rate. We analytically develop the power allocation framework that maximizes the EE subject to power budget, interference, and minimal rate constraints. In the numerical results, we show that the minimal rate may cause a transmission outage at low power budget values. We also highlighted the existence of optimal altitudes given the UAV location with respect to the different other terminals.

  7. Optimal relay selection and power allocation for cognitive two-way relaying networks

    KAUST Repository

    Pandarakkottilil, Ubaidulla

    2012-06-01

    In this paper, we present an optimal scheme for power allocation and relay selection in a cognitive radio network where a pair of cognitive (or secondary) transceiver nodes communicate with each other assisted by a set of cognitive two-way relays. The secondary nodes share the spectrum with a licensed primary user (PU), and each node is assumed to be equipped with a single transmit/receive antenna. The interference to the PU resulting from the transmission from the cognitive nodes is kept below a specified limit. We propose joint relay selection and optimal power allocation among the secondary user (SU) nodes achieving maximum throughput under transmit power and PU interference constraints. A closed-form solution for optimal allocation of transmit power among the SU transceivers and the SU relay is presented. Furthermore, numerical simulations and comparisons are presented to illustrate the performance of the proposed scheme. © 2012 IEEE.

  8. Wind speed power spectrum analysis for Bushland, Texas

    Energy Technology Data Exchange (ETDEWEB)

    Eggleston, E.D. [USDA-Agricultural Research Service, Bushland, TX (United States)

    1996-12-31

    Numerous papers and publications on wind turbulence have referenced the wind speed spectrum presented by Isaac Van der Hoven in his article entitled Power Spectrum of Horizontal Wind Speed Spectrum in the Frequency Range from 0.0007 to 900 Cycles per Hour. Van der Hoven used data measured at different heights between 91 and 125 meters above the ground, and represented the high frequency end of the spectrum with data from the peak hour of hurricane Connie. These facts suggest we should question the use of his power spectrum in the wind industry. During the USDA - Agricultural Research Service`s investigation of wind/diesel system power storage, using the appropriate wind speed power spectrum became a significant issue. We developed a power spectrum from 13 years of hourly average data, 1 year of 5 minute average data, and 2 particularly gusty day`s 1 second average data all collected at a height of 10 meters. While the general shape is similar to the Van der Hoven spectrum, few of his peaks were found in the Bushland spectrum. While higher average wind speeds tend to suggest higher amplitudes in the high frequency end of the spectrum, this is not always true. Also, the high frequency end of the spectrum is not accurately described by simple wind statistics such as standard deviation and turbulence intensity. 2 refs., 5 figs., 1 tab.

  9. Frequency shifts in stimulated Raman scattering

    International Nuclear Information System (INIS)

    Zinth, W.; Kaiser, W.

    1980-01-01

    The nonresonant contributions to the nonlinear susceptibility chisup(()3) produce a frequency chirp during stimulated Raman scattering. In the case of transient stimulated Raman scattering, the spectrum of the generated Stokes pulse is found at higher frequencies than expected from spontaneous Raman data. The frequency difference can be calculated from the theory of stimulated Raman scattering. (orig.)

  10. Macroeconomic influences on optimal asset allocation

    OpenAIRE

    Flavin, Thomas; Wickens, M.R.

    2003-01-01

    We develop a tactical asset allocation strategy that incorporates the effects of macroeconomic variables. The joint distribution of financial asset returns and the macroeconomic variables is modelled using a VAR with a multivariate GARCH (M-GARCH) error structure. As a result, the portfolio frontier is time varying and subject to contagion from the macroeconomic variable. Optimal asset allocation requires that this be taken into account. We illustrate how to do this using three ri...

  11. Human Capital and Risky Asset Allocation

    OpenAIRE

    Lu, Wenjie; Yu, Qun

    2011-01-01

    Much research has been done to examine the relation between investors' human capital and their financial asset allocation. While some showed that the value of human capital should be taken into consideration to make financial asset allocation decisions on the composition of investing portfolios, most argued not. In this paper, we selected the monthly return of 9 industrial ETFs from June of 2007 to July 2011, used the present value of total future income as estimate of human capital, and reli...

  12. Cost Allocation and Overpricing of Spare Parts.

    Science.gov (United States)

    1986-09-01

    traditional cost allocation process as reported in accounting literature. Horngren reported there are essen- tially three facets of cost allocation as...is for more than one unit of a product. Horngren reports cost accounting systems commonly have two major cost objectives: departments and products (8...Standards Board: Standards, Rules, and Regulations. Washington: Government Printing Office, 1985. 8. Horngren , Charles T. Cost Accounting : A Managerial

  13. Cost allocation. Combined heat and power production

    International Nuclear Information System (INIS)

    Sidzikauskas, V.

    2002-01-01

    The benefits of Combined Heat and Power (CHP) generation are discussed. The include improvement in energy intensity of 1% by 2010, 85-90% efficiency versus 40-50% of condensation power and others. Share of CHP electricity production in ERRA countries is presented.Solutions for a development CHP cost allocation are considered. Conclusion are presented for CHP production cost allocation. (R.P.)

  14. A High-Speed High-Frequency Broadband Acoustic Modem for Short-to-Medium Range Data Transmission in Ports, Very Shallow Waters and Deep Waters Using Spread-Spectrum Modulation and Decision Feedback Equalizing

    National Research Council Canada - National Science Library

    Beaujean, Pierre-Philippe; Spruance, John; Kriel, Dion

    2006-01-01

    ...: The long-term objective is the commercialization of a high-speed high-frequency acoustic modem transmitting data at true rates of up to 105,000 bps, at a maximum range of 500 m and operate between 240 kHz and 380 kHz...

  15. Allocation of authority in European health policy.

    Science.gov (United States)

    Adolph, Christopher; Greer, Scott L; Massard da Fonseca, Elize

    2012-11-01

    Although many study the effects of different allocations of health policy authority, few ask why countries assign responsibility over different policies as they do. We test two broad theories: fiscal federalism, which predicts rational governments will concentrate information-intensive operations at lower levels, and redistributive and regulatory functions at higher levels; and "politicized federalism", which suggests a combination of systematic and historically idiosyncratic political variables interfere with efficient allocation of authority. Drawing on the WHO Health in Transition country profiles, we present new data on the allocation of responsibility for key health care policy tasks (implementation, provision, finance, regulation, and framework legislation) and policy areas (primary, secondary and tertiary care, public health and pharmaceuticals) in the 27 EU member states and Switzerland. We use a Bayesian multinomial mixed logit model to analyze how different countries arrive at different allocations of authority over each task and area of health policy, and find the allocation of powers broadly follows fiscal federalism. Responsibility for pharmaceuticals, framework legislation, and most finance lodges at the highest levels of government, acute and primary care in the regions, and provision at the local and regional levels. Where allocation does not follow fiscal federalism, it appears to reflect ethnic divisions, the population of states and regions, the presence of mountainous terrain, and the timing of region creation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Energy-Efficient Power Allocation of Cognitive Radio Systems without CSI at the Transmitter

    KAUST Repository

    Sboui, Lokman

    2015-01-07

    Two major issues are facing today’s wireless communications evolution: -Spectrum scarcity: Need for more bandwidth. As a solution, the Cognitive Radio (CR) paradigm, where secondary users (unlicensed) share the spectrum with licensed users, was introduced. -Energy consumption and CO2 emission: The ICT produce 2% of global CO2 emission (equivalent to the aviation industry emission). The cellular networks produces 0.2%. As solution energy efficient systems should be designed rather than traditional spectral efficient systems. In this work, we aim to determine the optimal energy efficient power allocation of CR when the channel state information at the transmitter CSI-T is not available.

  17. Energy-Efficient Power Allocation of Cognitive Radio Systems without CSI at the Transmitter

    KAUST Repository

    Sboui, Lokman; Rezki, Zouheir; Alouini, Mohamed-Slim

    2015-01-01

    Two major issues are facing today’s wireless communications evolution: -Spectrum scarcity: Need for more bandwidth. As a solution, the Cognitive Radio (CR) paradigm, where secondary users (unlicensed) share the spectrum with licensed users, was introduced. -Energy consumption and CO2 emission: The ICT produce 2% of global CO2 emission (equivalent to the aviation industry emission). The cellular networks produces 0.2%. As solution energy efficient systems should be designed rather than traditional spectral efficient systems. In this work, we aim to determine the optimal energy efficient power allocation of CR when the channel state information at the transmitter CSI-T is not available.

  18. Unmet Needs of Families of School-Aged Children with an Autism Spectrum Disorder

    Science.gov (United States)

    Brown, Hilary K.; Ouellette-Kuntz, Helene; Hunter, Duncan; Kelley, Elizabeth; Cobigo, Virginie

    2012-01-01

    Background: To aid decision making regarding the allocation of limited resources, information is needed on the perceived unmet needs of parents of school-aged children with an autism spectrum disorder. Materials and Methods: A cross-sectional survey was conducted of 101 Canadian families of school-aged children with an autism spectrum disorder.…

  19. Online Job Allocation with Hard Allocation Ratio Requirement (Author’s Manuscript)

    Science.gov (United States)

    2016-04-14

    server divided by its capacity. Specifically , let nj be the number of jobs that have already been allocated to server j. When job i arrives, it is...decisions solely based on current system state is needed. The problem of online job allocation has attracted much attention . Most current studies study...closed-form expressions for their performance. Specifically , we prove that, in order to allocate at least 1− 1θ of jobs , the two policies only need to

  20. Joint interference management and resource allocation for device-to-device (D2D) communications underlying downlink/uplink decoupled (DUDe) heterogeneous networks

    KAUST Repository

    Celik, Abdulkadir

    2017-07-31

    In this paper, resource allocation and co-tier/cross-tier interference management are investigated for D2D-enabled heterogeneous networks (HetNets) where tiers 1, 2, and 3 consist of macrocells, smallcells, and D2D pairs, respectively. We first propose a D2D-enabled fractional frequency reuse scheme for uplink (UL) HetNets where macrocell subregions are preassigned to different subbands (SBs) in order to mitigate the tier-1↔tier-1 interference. Nevertheless, cell-edge macrocell user equipments (MUEs) with high transmission powers still form dead-zones for nearby smallcell UEs (SUEs) and D2D UEs (DUEs). One of the simple but yet novel means of the dead-zone alleviation is associating the cell-edge MUEs with nearby smallcells, which is also known as downlink (DL)/UL decoupling (DUDe). Subject to quality of service (QoS) requirements and power constraints, we formulate a joint SB assignment and resource block (RB) allocation optimization as a mixed integer non-linear programming (MINLP) problem to maximize the D2D sum rate and minimize the co-tier/cross-tier interference. Based on tolerable interference limit, we propose a fast yet high-performance suboptimal solution to jointly assign available SBs and RBs to smallcells. A D2D mode selection and resource allocation framework is then developed for DUEs. As traditional DL/UL Coupled (DUCo) scheme generates significant interference proportional to cellular user density and user association bias factor, results obtained from the combination of proposed methods and developed algorithms reveal the potential of DUDe for co-tier/cross-tier interference mitigation which opens more room for spectrum reuse of DUEs.

  1. A generic interference model for uplink OFDMA networks with fractional frequency reuse

    KAUST Repository

    Tabassum, Hina

    2014-03-01

    Fractional frequency reuse (FFR) has emerged as a viable solution to coordinate and mitigate cochannel interference (CCI) in orthogonal frequency-division multiple-access (OFDMA)-based wireless cellular networks. The incurred CCI in cellular networks with FFR is highly uncertain and varies as a function of various design parameters that include the user scheduling schemes, the transmit power distribution among multiple allocated subcarriers, the partitioning of the cellular region into cell-edge and cell-center zones, the allocation of spectrum within each zone, and the channel reuse factors. To this end, this paper derives a generic analytical model for uplink CCI in multicarrier OFDMA networks with FFR. The derived expressions capture several network design parameters and are applicable to any composite fading-channel models. The accuracy of the derivations is verified via Monte Carlo simulations. Moreover, their usefulness is demonstrated by obtaining closed-form expressions for the Rayleigh fading-channel model and by evaluating important network performance metrics such as ergodic capacity. Numerical results provide useful system design guidelines and highlight the trade-offs associated with the deployment of FFR schemes in OFDMA-based networks. © 2013 IEEE.

  2. A generic interference model for uplink OFDMA networks with fractional frequency reuse

    KAUST Repository

    Tabassum, Hina; Dawy, Zaher; Alouini, Mohamed-Slim; Yilmaz, Ferkan

    2014-01-01

    Fractional frequency reuse (FFR) has emerged as a viable solution to coordinate and mitigate cochannel interference (CCI) in orthogonal frequency-division multiple-access (OFDMA)-based wireless cellular networks. The incurred CCI in cellular networks with FFR is highly uncertain and varies as a function of various design parameters that include the user scheduling schemes, the transmit power distribution among multiple allocated subcarriers, the partitioning of the cellular region into cell-edge and cell-center zones, the allocation of spectrum within each zone, and the channel reuse factors. To this end, this paper derives a generic analytical model for uplink CCI in multicarrier OFDMA networks with FFR. The derived expressions capture several network design parameters and are applicable to any composite fading-channel models. The accuracy of the derivations is verified via Monte Carlo simulations. Moreover, their usefulness is demonstrated by obtaining closed-form expressions for the Rayleigh fading-channel model and by evaluating important network performance metrics such as ergodic capacity. Numerical results provide useful system design guidelines and highlight the trade-offs associated with the deployment of FFR schemes in OFDMA-based networks. © 2013 IEEE.

  3. Improved Fiber Bragg Grating Array OFFH-CDMA System Using a Novel Frequency-Overlapping Multigroup Method

    Science.gov (United States)

    Peng, Wei-Ren; Lin, Wen-Piao; Chi, Sien

    2006-03-01

    The authors propose a novel frequency-overlapping multigroup scheme for a passive all-optical fast-frequency hopped code-division multiple-access (OFFH-CDMA) system based on fiber Bragg grating array (FBGA). In the conventional scheme, the users are assigned those codes constructed on the nonoverlapping frequency slots, and therefore the bandgaps between the adjacent gratings are wasted. To make a more efficient use of the optical spectrum, the proposed scheme divided the users into several groups, and assigned the codes, which interleaved to each other to the different groups. In addition to the higher utilization of the spectrum, the interleaved nature of the frequency allocations of different groups will make the groups less correlated and, hence, lower the multiple-access interference (MAI). The corresponding codeset and its constraints for this new scheme are also developed and analyzed. The performance of the system in terms of the correlation functions and bit error rate (BER) are given in both the conventional and the proposed schemes. The numerical results show that, with the multigroup scheme, performance is much improved compared to the conventional scheme.

  4. Energy Efficient Resource Allocation for Phantom Cellular Networks

    KAUST Repository

    Abdelhady, Amr

    2016-04-01

    Multi-tier heterogeneous networks have become an essential constituent for next generation cellular networks. Meanwhile, energy efficiency (EE) has been considered a critical design criterion along with the traditional spectral efficiency (SE) metric. In this context, we study power and spectrum allocation for the recently proposed two-tier network architecture known as phantom cellular networks. The optimization framework includes both EE and SE. First, we consider sparsely deployed cells experiencing negligible interference and assume perfect channel state information (CSI). For this setting, we propose an algorithm that finds the SE and EE resource allocation strategies. Then, we compare the performance of both design strategies versus number of users, and phantom cells share of the total available resource units (RUs). We aim to investigate the effect of some system parameters to achieve improved SE performance at a non-significant loss in EE performance, or vice versa. It is found that increasing phantom cells share of RUs decreases the SE performance loss due to EE optimization when compared with the optimized SE performance. Second, we consider the densely deployed phantom cellular networks and model the EE optimization problem having into consideration the inevitable interference and imperfect channel estimation. To this end, we propose three resource allocation strategies aiming at optimizing the EE performance metric of this network. Furthermore, we investigate the effect of changing some of the system parameters on the performance of the proposed strategies, such as phantom cells share of RUs, number of deployed phantom cells within a macro cell coverage, number of pilots and the maximum power available for transmission by the phantom cells BSs. It is found that increasing the number of pilots deteriorates the EE performance of the whole setup, while increasing maximum power available for phantom cells transmissions reduces the EE of the whole setup in a

  5. Spatial dependence in wind and optimal wind power allocation: A copula-based analysis

    International Nuclear Information System (INIS)

    Grothe, Oliver; Schnieders, Julius

    2011-01-01

    The investment decision on the placement of wind turbines is, neglecting legal formalities, mainly driven by the aim to maximize the expected annual energy production of single turbines. The result is a concentration of wind farms at locations with high average wind speed. While this strategy may be optimal for single investors maximizing their own return on investment, the resulting overall allocation of wind turbines may be unfavorable for energy suppliers and the economy because of large fluctuations in the overall wind power output. This paper investigates to what extent optimal allocation of wind farms in Germany can reduce these fluctuations. We analyze stochastic dependencies of wind speed for a large data set of German on- and offshore weather stations and find that these dependencies turn out to be highly nonlinear but constant over time. Using copula theory we determine the value at risk of energy production for given allocation sets of wind farms and derive optimal allocation plans. We find that the optimized allocation of wind farms may substantially stabilize the overall wind energy supply on daily as well as hourly frequency. - Highlights: → Spatial modeling of wind forces in Germany. → A novel way to assess nonlinear dependencies of wind forces by copulas. → Wind turbine allocation by maximizing lower quantiles of energy production. → Optimal results show major increase in reliable part of wind energy.

  6. A cross-layer resource allocation scheme for spatial multiplexing-based MIMO-OFDMA systems

    Directory of Open Access Journals (Sweden)

    Al-Shatri Hussein

    2011-01-01

    Full Text Available Abstract We investigate the resource allocation problem for the downlink of a multiple-input multiple-output orthogonal frequency division multiple access (MIMO-OFDMA system. The sum rate maximization itself cannot cope with fairness among users. Hence, we address this problem in the context of the utility-based resource allocation presented in earlier papers. This resource allocation method allows to enhance the efficiency and guarantee fairness among users by exploiting multiuser diversity, frequency diversity, as well as time diversity. In this paper, we treat the overall utility as the quality of service indicator and design utility functions with respect to the average transmission rate in order to simultaneously provide two services, real-time and best-effort. Since the optimal solutions are extremely computationally complex to obtain, we propose a suboptimal joint subchannel and power control algorithm that converges very fast and simplifies the MIMO resource allocation problem into a single-input single-output resource allocation problem. Simulation results indicate that using the proposed method achieves near-optimum solutions, and the available resources are distributed more fairly among users.

  7. Near-optimal power allocation with PSO algorithm for MIMO cognitive networks using multiple AF two-way relays

    KAUST Repository

    Alsharoa, Ahmad M.

    2014-06-01

    In this paper, the problem of power allocation for a multiple-input multiple-output two-way system is investigated in underlay Cognitive Radio (CR) set-up. In the CR underlay mode, secondary users are allowed to exploit the spectrum allocated to primary users in an opportunistic manner by respecting a tolerated temperature limit. The secondary networks employ an amplify-and-forward two-way relaying technique in order to maximize the sum rate under power budget and interference constraints. In this context, we formulate an optimization problem that is solved in two steps. First, we derive a closed-form expression of the optimal power allocated to terminals. Then, we employ a strong optimization tool based on particle swarm optimization algorithm to find the power allocated to secondary relays. Simulation results demonstrate the efficiency of the proposed solution and analyze the impact of some system parameters on the achieved performance. © 2014 IEEE.

  8. SOME NOTES ON COST ALLOCATION IN MULTICASTING

    Directory of Open Access Journals (Sweden)

    Darko Skorin-Kapov

    2012-12-01

    Full Text Available We analyze the cost allocation strategies with the problef of broadcasting information from some source to a number of communication network users. A multicast routing chooses a minimum cost tree network that spans the source and all the receivers. The cost of such a network is distributed among its receivers who may be individuals or organizations with possibly conflicting interests. Providing network developers, users and owners with practical computable 'fair' cost allocation solution procedures is of great importance for network mamagement. Consequently, this multidisciplinary problem was extensively studied by Operational Researchers, Economists, Mathematicians and Computer Scientists. The fairness of various proposed solutions was even argued in US courts. This presentation overviews some previously published, as well as some recent results, in the development of algorithmic mechanisms to efficiently compute 'attractive' cost allocation solutions for multicast networks. Specifically, we will analyze cooperative game theory based cost allocation models that avoid cross subsidies and/or are distance and population monotonic. We will also present some related open cost allocation problems and the potential contribution that such models might make to this problem in the future.

  9. Cognitive allocation and the control room

    International Nuclear Information System (INIS)

    Paradies, M.W.

    1985-01-01

    One of the weakest links in the design of nuclear power plants is the inattention to the needs and capabilities of the operators. This flaw causes decreased plant reliability and reduced plant safety. To solve this problem the designer must, in the earliest stages of the design process, consider the operator's abilities. After the system requirements have been established, the designer must consider what functions to allocate to each part of the system. The human must be considered as part of this system. The allocation of functions needs to consider not only the mechanical tasks to be performed, but also the control requirements and the overall control philosophy. In order for the designers to consider the control philosophy, they need to know what control decisions should be automated and what decisions should be made by an operator. They also need to know how these decisions will be implemented: by an operator or by automation. ''Cognitive Allocation'' is the allocation of the decision making process between operators and machines. It defines the operator's role in the system. When designing a power plant, a cognitive allocation starts the process of considering the operator's abilities. This is the first step to correcting the weakest link in the current plant design

  10. Methodology for allocating reliability and risk

    International Nuclear Information System (INIS)

    Cho, N.Z.; Papazoglou, I.A.; Bari, R.A.

    1986-05-01

    This report describes a methodology for reliability and risk allocation in nuclear power plants. The work investigates the technical feasibility of allocating reliability and risk, which are expressed in a set of global safety criteria and which may not necessarily be rigid, to various reactor systems, subsystems, components, operations, and structures in a consistent manner. The report also provides general discussions on the problem of reliability and risk allocation. The problem is formulated as a multiattribute decision analysis paradigm. The work mainly addresses the first two steps of a typical decision analysis, i.e., (1) identifying alternatives, and (2) generating information on outcomes of the alternatives, by performing a multiobjective optimization on a PRA model and reliability cost functions. The multiobjective optimization serves as the guiding principle to reliability and risk allocation. The concept of ''noninferiority'' is used in the multiobjective optimization problem. Finding the noninferior solution set is the main theme of the current approach. The final step of decision analysis, i.e., assessment of the decision maker's preferences could then be performed more easily on the noninferior solution set. Some results of the methodology applications to a nontrivial risk model are provided, and several outstanding issues such as generic allocation, preference assessment, and uncertainty are discussed. 29 refs., 44 figs., 39 tabs

  11. Frequency standards

    CERN Document Server

    Riehle, Fritz

    2006-01-01

    Of all measurement units, frequency is the one that may be determined with the highest degree of accuracy. It equally allows precise measurements of other physical and technical quantities, whenever they can be measured in terms of frequency.This volume covers the central methods and techniques relevant for frequency standards developed in physics, electronics, quantum electronics, and statistics. After a review of the basic principles, the book looks at the realisation of commonly used components. It then continues with the description and characterisation of important frequency standards

  12. The effect of fast neutrons, as compared with X-rays upon mutation spectrum and mutation frequency in Arabidopsis thaliana (L.) Heynh. and Hordeum vulgare L. in relation to evaluation of the BARN-reactor

    International Nuclear Information System (INIS)

    Dellaert, L.M.W.

    1980-01-01

    Explanations were sought for the 'saturation' in mutant frequency, observed after relatively high irradiation doses (fast neutrons and X-rays) in Arabidopsis thaliana (L.) Heynh, when scoring for mutants is done in the siliques (Mueller's embryotest) of the 'main' inflorescence of M 1 -plants. Studies have been carried out on the effect of the presence of dithiothreitol (DTT) during irradiation, on fast neutron and X-ray induced M 1 -ovule sterility, M 2 -embryonic lethals, M 2 -chlorophyll mutants and M 2 -viable mutants in Arabidopsis thaliana. It was found that DTT provides considerable protection against both fast neutron and X-ray induced genetic damage. (Auth.)

  13. An Analysis and Allocation System for Library Collections Budgets: The Comprehensive Allocation Process (CAP)

    Science.gov (United States)

    Lyons, Lucy Eleonore; Blosser, John

    2012-01-01

    The "Comprehensive Allocation Process" (CAP) is a reproducible decision-making structure for the allocation of new collections funds, for the reallocation of funds within stagnant budgets, and for budget cuts in the face of reduced funding levels. This system was designed to overcome common shortcomings of current methods. Its philosophical…

  14. Soil Moisture Active Passive (SMAP) Microwave Radiometer Radio-Frequency Interference (RFI) Mitigation: Initial On-Orbit Results

    Science.gov (United States)

    Mohammed, Priscilla N.; Piepmeier, Jeffrey R.; Johnson, Joel T.; Aksoy, Mustafa; Bringer, Alexandra

    2015-01-01

    The Soil Moisture Active Passive (SMAP) mission, launched in January 2015, provides global measurements of soil moisture using a microwave radiometer. SMAPs radiometer passband lies within the passive frequency allocation. However, both unauthorized in-band transmitters as well as out-of-band emissions from transmitters operating at frequencies adjacent to this allocated spectrum have been documented as sources of radio frequency interference (RFI) to the L-band radiometers on SMOS and Aquarius. The spectral environment consists of high RFI levels as well as significant occurrences of low level RFI equivalent to 0.1 to 10 K. The SMAP ground processor reports the antenna temperature both before and after RFI mitigation is applied. The difference between these quantities represents the detected RFI level. The presentation will review the SMAP RFI detection and mitigation procedure and discuss early on-orbit RFI measurements from the SMAP radiometer. Assessments of global RFI properties and source types will be provided, as well as the implications of these results for SMAP soil moisture measurements.

  15. Spectrum of pediatric neuromyelitis optica.

    Science.gov (United States)

    Lotze, Timothy E; Northrop, Jennifer L; Hutton, George J; Ross, Benjamin; Schiffman, Jade S; Hunter, Jill V

    2008-11-01

    Our goal was to describe the spectrum of clinical phenotypes, laboratory and imaging features, and treatment in pediatric patients with neuromyelitis optica. The study consisted of a retrospective chart review of patients followed in a pediatric multiple sclerosis center with a diagnosis of neuromyelitis optica spectrum disorder. Nine patients with neuromyelitis optica spectrum disorders were included, all of whom were female. There were 4 black children, 2 Latin American children, 2 white children, and 1 child of mixed Latin American/white heritage. Median age at initial attack was 14 years (range: 1.9-16 years). Median disease duration was 4 years (range: 0.6-9 years). Tests for neuromyelitis optica immunoglobulin G were positive for 7 patients. Eight patients had transverse myelitis and optic neuritis, and 1 patient had longitudinally extensive transverse myelitis without optic neuritis but had a positive neuromyelitis optica immunoglobulin G antibody titer. Cerebral involvement on MRI was found in all subjects, 5 of whom were symptomatic with encephalopathy, seizures, hemiparesis, aphasia, vomiting, or hiccups. Immunosuppressive therapy reduced attack frequency and progression of disability. Pediatric neuromyelitis optica has a diverse clinical presentation and may be difficult to distinguish from multiple sclerosis in the early stages of the disease. The recognition of the broad spectrum of this disease to include signs and symptoms of brain involvement is aided by the availability of a serum biomarker: neuromyelitis optica immunoglobulin G. Early diagnosis and immunosuppresive treatment may help to slow the accumulation of severe disability.

  16. Variations in the Produce-Associated Microbiota and the Occurrence Frequency of Extended-Spectrum Beta-Lactamase Gram-Negative Bacteria Result in Different Level of Ingestion Risks

    KAUST Repository

    Bokhari, Osama

    2016-04-01

    A monitoring effort that spanned across one and a half years was conducted to examine three types of produce-associated microbiota. Produce type was determined to be the predominant factor affecting the microbial communities. Other significant factors that resulted in differences in the microbial populations were the origin and sampling date. Specifically, produce-associated microbiota among lettuce and tomatoes clustered based on the sampling period. Through molecular and cultivation-based approaches, sporadic presence of extended spectrum beta-lactamase (ESBL)-positive Klebsiella pneumoniae and Acinetobacter baumannii was detected on lettuce and cucumbers during certain periods of sampling. Quantitative microbial risk assessment denoted varying levels of ingestion risks associated with different types of produce. In particular, the risks arising from ESBL-positive K. pneumoniae in the lettuce were higher than the acceptable annual risk of 10-4. Commonly used approaches to clean and wash the produce were insufficient in removing majority of the produce-associated microbiota. More invasive cleaning approaches or thorough cooking of the produce would be required to mitigate the associated risks. Most of the current reports of ESBL-positive bacterial isolates were identified in nosocomial environment. However, the carriage of such drug-resistant bacteria in food that is consumed daily

  17. 24 CFR 791.404 - Field Office allocation planning.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Field Office allocation planning... Allocation of Budget Authority for Housing Assistance § 791.404 Field Office allocation planning. (a) General objective. The allocation planning process should provide for the equitable distribution of available budget...

  18. 18 CFR 367.28 - Methods of allocation.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Methods of allocation... Instructions § 367.28 Methods of allocation. Indirect costs and compensation for use of capital must be... allocation. Both direct and allocated indirect costs on projects must be assigned among those companies in...

  19. 17 CFR 256.01-11 - Methods of allocation.

    Science.gov (United States)

    2010-04-01

    ... applicable and currently effective methods of allocation filed with the Commission. Both direct and allocated... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Methods of allocation. 256.01... HOLDING COMPANY ACT OF 1935 General Instructions § 256.01-11 Methods of allocation. Indirect costs and...

  20. 40 CFR 60.4142 - Hg allowance allocations.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Hg allowance allocations. 60.4142... Coal-Fired Electric Steam Generating Units Hg Allowance Allocations § 60.4142 Hg allowance allocations. (a)(1) The baseline heat input (in MMBtu) used with respect to Hg allowance allocations under...

  1. Participation behavior and social welfare in repeated task allocations

    NARCIS (Netherlands)

    Ye, Q.C.; Zhang, Y.

    2016-01-01

    Task allocation problems have focused on achieving one-shot optimality. In practice, many task allocation problems are of repeated nature, where the allocation outcome of previous rounds may influence the participation of agents in subsequent rounds, and consequently, the quality of the allocations

  2. Railway Track Allocation: Models and Methods

    DEFF Research Database (Denmark)

    Lusby, Richard Martin; Larsen, Jesper; Ehrgott, Matthias

    2011-01-01

    Efficiently coordinating the movement of trains on a railway network is a central part of the planning process for a railway company. This paper reviews models and methods that have been proposed in the literature to assist planners in finding train routes. Since the problem of routing trains......, and train routing problems, group them by railway network type, and discuss track allocation from a strategic, tactical, and operational level....... on a railway network entails allocating the track capacity of the network (or part thereof) over time in a conflict-free manner, all studies that model railway track allocation in some capacity are considered relevant. We hence survey work on the train timetabling, train dispatching, train platforming...

  3. Railway Track Allocation: Models and Methods

    DEFF Research Database (Denmark)

    Lusby, Richard Martin; Larsen, Jesper; Ehrgott, Matthias

    Eciently coordinating the movement of trains on a railway network is a central part of the planning process for a railway company. This paper reviews models and methods that have been proposed in the literature to assist planners in nding train routes. Since the problem of routing trains......, and train routing problems, group them by railway network type, and discuss track allocation from a strategic, tactical, and operational level....... on a railway network entails allocating the track capacity of the network (or part thereof) over time in a con ict-free manner, all studies that model railway track allocation in some capacity are considered relevant. We hence survey work on the train timetabling, train dispatching, train platforming...

  4. Task mapping for non-contiguous allocations.

    Energy Technology Data Exchange (ETDEWEB)

    Leung, Vitus Joseph; Bunde, David P.; Ebbers, Johnathan; Price, Nicholas W.; Swank, Matthew.; Feer, Stefan P.; Rhodes, Zachary D.

    2013-02-01

    This paper examines task mapping algorithms for non-contiguously allocated parallel jobs. Several studies have shown that task placement affects job running time for both contiguously and non-contiguously allocated jobs. Traditionally, work on task mapping either uses a very general model where the job has an arbitrary communication pattern or assumes that jobs are allocated contiguously, making them completely isolated from each other. A middle ground between these two cases is the mapping problem for non-contiguous jobs having a specific communication pattern. We propose several task mapping algorithms for jobs with a stencil communication pattern and evaluate them using experiments and simulations. Our strategies improve the running time of a MiniApp by as much as 30% over a baseline strategy. Furthermore, this improvement increases markedly with the job size, demonstrating the importance of task mapping as systems grow toward exascale.

  5. Optimal allocation of reviewers for peer feedback

    DEFF Research Database (Denmark)

    Wind, David Kofoed; Jensen, Ulf Aslak; Jørgensen, Rasmus Malthe

    2017-01-01

    feedback to be effective students should give and receive useful feedback. A key challenge in peer feedback is allocating the feedback givers in a good way. It is important that reviewers are allocated to submissions such that the feedback distribution is fair - meaning that all students receive good......Peer feedback is the act of letting students give feedback to each other on submitted work. There are multiple reasons to use peer feedback, including students getting more feedback, time saving for teachers and increased learning by letting students reflect on work by others. In order for peer...... indicated the quality of the feedback. Using this model together with historical data we calculate the feedback-giving skill of each student and uses that as input to an allocation algorithm that assigns submissions to reviewers, in order to optimize the feedback quality for all students. We test...

  6. Prospect theory reflects selective allocation of attention.

    Science.gov (United States)

    Pachur, Thorsten; Schulte-Mecklenbeck, Michael; Murphy, Ryan O; Hertwig, Ralph

    2018-02-01

    There is a disconnect in the literature between analyses of risky choice based on cumulative prospect theory (CPT) and work on predecisional information processing. One likely reason is that for expectation models (e.g., CPT), it is often assumed that people behaved only as if they conducted the computations leading to the predicted choice and that the models are thus mute regarding information processing. We suggest that key psychological constructs in CPT, such as loss aversion and outcome and probability sensitivity, can be interpreted in terms of attention allocation. In two experiments, we tested hypotheses about specific links between CPT parameters and attentional regularities. Experiment 1 used process tracing to monitor participants' predecisional attention allocation to outcome and probability information. As hypothesized, individual differences in CPT's loss-aversion, outcome-sensitivity, and probability-sensitivity parameters (estimated from participants' choices) were systematically associated with individual differences in attention allocation to outcome and probability information. For instance, loss aversion was associated with the relative attention allocated to loss and gain outcomes, and a more strongly curved weighting function was associated with less attention allocated to probabilities. Experiment 2 manipulated participants' attention to losses or gains, causing systematic differences in CPT's loss-aversion parameter. This result indicates that attention allocation can to some extent cause choice regularities that are captured by CPT. Our findings demonstrate an as-if model's capacity to reflect characteristics of information processing. We suggest that the observed CPT-attention links can be harnessed to inform the development of process models of risky choice. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  7. Frequency Synthesiser

    NARCIS (Netherlands)

    Drago, Salvatore; Sebastiano, Fabio; Leenaerts, Dominicus M.W.; Breems, Lucien J.; Nauta, Bram

    2016-01-01

    A low power frequency synthesiser circuit (30) for a radio transceiver, the synthesiser circuit comprising: a digital controlled oscillator configured to generate an output signal having a frequency controlled by an input digital control word (DCW); a feedback loop connected between an output and an

  8. Frequency synthesiser

    NARCIS (Netherlands)

    Drago, S.; Sebastiano, Fabio; Leenaerts, Dominicus Martinus Wilhelmus; Breems, Lucien Johannes; Nauta, Bram

    2010-01-01

    A low power frequency synthesiser circuit (30) for a radio transceiver, the synthesiser circuit comprising: a digital controlled oscillator configured to generate an output signal having a frequency controlled by an input digital control word (DCW); a feedback loop connected between an output and an

  9. Many channel spectrum unfolding

    International Nuclear Information System (INIS)

    Najzer, M.; Glumac, B.; Pauko, M.

    1980-01-01

    The principle of the ITER unfolding code as used for the many channel spectrum unfolding is described. Its unfolding ability is tested on seven typical neutron spectra. The effect of the initial spectrum approximation upon the solution is discussed

  10. Pulsar Emission Spectrum

    OpenAIRE

    Gruzinov, Andrei

    2013-01-01

    Emission spectrum is calculated for a weak axisymmetric pulsar. Also calculated are the observed spectrum, efficiency, and the observed efficiency. The underlying flow of electrons and positrons turns out to be curiously intricate.

  11. Autism Spectrum Disorder

    Science.gov (United States)

    ... Caregiver Education » Fact Sheets Autism Spectrum Disorder Fact Sheet What is autism spectrum disorder? What are some ... of mutations in individual genes but rather spontaneous coding mutations across many genes. De novo mutations may ...

  12. Allocation of Decommissioning and Waste Liabilities

    International Nuclear Information System (INIS)

    Varley, Geoff

    2011-11-01

    The work demonstrates that there are a number of methods available for cost allocation, the pros and cons of which are examined. The study investigates potential proportional and incremental methods in some depth. A recommendation in principle to use the latter methodology is given. It is concluded that a 'fair assumption' is that the potential allocation of costs for 'the RMA Leaching Hall' probably is small, in relation to the total costs, and estimated to be not more than about 175 kSEK, plus any costs associated with decommissioning/ disposal of a number of small pieces of equipment added by the current operator

  13. Vascularized Composite Allografts: Procurement, Allocation, and Implementation.

    Science.gov (United States)

    Rahmel, Axel

    Vascularized composite allotransplantation is a continuously evolving area of modern transplant medicine. Recently, vascularized composite allografts (VCAs) have been formally classified as 'organs'. In this review, key aspects of VCA procurement are discussed, with a special focus on interaction with the procurement of classical solid organs. In addition, options for a matching and allocation system that ensures VCA donor organs are allocated to the best-suited recipients are looked at. Finally, the different steps needed to promote VCA transplantation in society in general and in the medical community in particular are highlighted.

  14. Resource allocation using ANN in LTE

    Science.gov (United States)

    Yigit, Tuncay; Ersoy, Mevlut

    2017-07-01

    LTE is the 4th generation wireless network technology, which provides flexible bandwidth, higher data speeds and lower delay. Difficulties may be experienced upon an increase in the number of users in LTE. The objective of this study is to ensure a faster solution to any such resource allocation problems which might arise upon an increase in the number of users. A fast and effective solution has been obtained by making use of Artificial Neural Network. As a result, fast working artificial intelligence methods may be used in resource allocation problems during operation.

  15. Cross-spectrum symbol synchronization

    Science.gov (United States)

    Mccallister, R. D.; Simon, M. K.

    1981-01-01

    A popular method of symbol synchronization exploits one aspect of generalized harmonic analysis, normally referred to as the cross-spectrum. Utilizing nonlinear techniques, the input symbol energy is effectively concentrated onto multiples of the symbol clock frequency, facilitating application of conventional phase lock synchronization techniques. A general treatment of the cross-spectrum technique is developed and shown to be applicable across a broad class of symbol modulation formats. An important specific symbol synchronization application is then treated, focusing the general development to provide both insight and quantitative measure of the performance impact associated with variation in these key synchronization parameters: symbol modulation format, symbol transition probability, symbol energy to noise density ratio, and symbol rate to filter bandwidth ratio.

  16. Type monotonic allocation schemes for multi-glove games

    OpenAIRE

    Brânzei, R.; Solymosi, T.; Tijs, S.H.

    2007-01-01

    Multiglove markets and corresponding games are considered.For this class of games we introduce the notion of type monotonic allocation scheme.Allocation rules for multiglove markets based on weight systems are introduced and characterized.These allocation rules generate type monotonic allocation schemes for multiglove games and are also helpful in proving that each core element of the corresponding game is extendable to a type monotonic allocation scheme.The T-value turns out to generate a ty...

  17. Doppler Frequency Shift in Ocean Wave Measurements: Frequency Downshift of a Fixed Spectral Wave Number Component by Advection of Wave Orbital Velocity

    National Research Council Canada - National Science Library

    Hwang, Paul

    2006-01-01

    ... at he expected intrinsic frequency in the frequency spectrum measured by a stationary probe. The advection of the wave number component by the orbital current of background waves produces a net downshift in the encounter frequency...

  18. [Continuum based fast Fourier transform processing of infrared spectrum].

    Science.gov (United States)

    Liu, Qing-Jie; Lin, Qi-Zhong; Wang, Qin-Jun; Li, Hui; Li, Shuai

    2009-12-01

    To recognize ground objects with infrared spectrum, high frequency noise removing is one of the most important phases in spectrum feature analysis and extraction. A new method for infrared spectrum preprocessing was given combining spectrum continuum processing and Fast Fourier Transform (CFFT). Continuum was firstly removed from the noise polluted infrared spectrum to standardize hyper-spectra. Then the spectrum was transformed into frequency domain (FD) with fast Fourier transform (FFT), separating noise information from target information After noise eliminating from useful information with a low-pass filter, the filtered FD spectrum was transformed into time domain (TD) with fast Fourier inverse transform. Finally the continuum was recovered to the spectrum, and the filtered infrared spectrum was achieved. Experiment was performed for chlorite spectrum in USGS polluted with two kinds of simulated white noise to validate the filtering ability of CFFT by contrast with cubic function of five point (CFFP) in time domain and traditional FFT in frequency domain. A circle of CFFP has limited filtering effect, so it should work much with more circles and consume more time to achieve better filtering result. As for conventional FFT, Gibbs phenomenon has great effect on preprocessing result at edge bands because of special character of rock or mineral spectra, while works well at middle bands. Mean squared error of CFFT is 0. 000 012 336 with cut-off frequency of 150, while that of FFT and CFFP is 0. 000 061 074 with cut-off frequency of 150 and 0.000 022 963 with 150 working circles respectively. Besides the filtering result of CFFT can be improved by adjusting the filter cut-off frequency, and has little effect on working time. The CFFT method overcomes the Gibbs problem of FFT in spectrum filtering, and can be more convenient, dependable, and effective than traditional TD filter methods.

  19. Instant centre frequency at anaesthetic induction--a new way to analyse sympathovagal balance.

    Science.gov (United States)

    de Souza Neto, Edmundo Pereira; Cerutti, Catherine; Loufoua, Joseph; Saroul, Christine; Chiari, Pascal; Custaud, Marc-Antoine; Lehot, Jean-Jacques

    2003-02-01

    The instant centre frequency (ICF) of RR interval has been proposed as a global index to analyse the sympathovagal interaction in the heart. The aim of this study was to assess the ICF during anaesthesia to test if it can reliably capture the neural control of the cardiovascular system. Twenty-four ASA II or III patients scheduled for cardiac surgery were included in the study. They were allocated in two groups: control, no treatment (group 1, n = 12), and beta-adrenergic blockade by atenolol (group 2, n = 12). Spectra of pulse interval series were computed with a time-frequency method and they were divided into: very low frequency (VLF, 0.000-0.040 Hz), low frequency (LF, 0.050-0.150 Hz) and high frequency (HF, 0.160-0.500 Hz). Normalized power was obtained by dividing the cumulative power within each frequency band (LF or HF) by the sum of LF and HF; the ratio of LF/HF was also calculated. Instant centre frequency is a time-varying parameter that the evolution along time of the gravity centrum of a local spectrum. All spectral indexes were recorded at the following time points: before induction, after induction and before intubation, during intubation, and after intubation. The atenolol group had lower normalized LF and the LF/HF ratio (P ICF was higher in atenolol group at all times. The ICF shifted towards HF frequency after induction and before intubation and shifted towards LF during intubation in both groups. The autonomic nervous system control on the heart through the interaction of sympathetic and parasympathetic reflex mechanisms could be studied by the ICF. The ICF may assess the autonomic cardiac modulation and may provide useful information for anaesthetic management.

  20. Flexible power and bandwidth allocation in mobile satellites

    Science.gov (United States)

    Keyes, L. A.

    The introduction of L-band mobile communication services by spot beam satellites creates a payload design challenge due to uncertainty in the location and size of the new market to be served. A combination of payload technologies that allow a flexible allocation of power and bandwidth to any portion of the coverage area is described. Power flexibility is achieved by a novel combination of a low-level beam-forming network and a matrix power module which ensures equal sharing of power among individual amplifiers. This eliminates the loss of efficiency and increased mass when an amplifier associated with a beam must be over-designed to meet uncertainties in power distribution between beams. Flexibility in allocation of bandwidth to beams is achieved by intermediate frequency subdivision of the L-band service categories defined by ITU. These spectral subdivisions are assigned to beams by an IF interconnect matrix having beam ports and filter ports as inputs and outputs, respectively. Two such filter switch matrices are required, one for the inbound L-band to feeder link transponder, and one for the outbound feeder link to L-band transponder.

  1. A localized cooperative wideband spectrum sensing for dynamic access of TV bands using RF sensor networks

    KAUST Repository

    Mirza, Mohammed; Alouini, Mohamed-Slim

    2011-01-01

    In this paper we address and simulate a Radio Frequency (RF) sensor network for a cooperative spectrum sensing and localization scheme. The proposed method integrates a Wavelet based Multi-Resolution Spectrum Sensing (MRSS), an N-bit hard

  2. Trajectories of goods in distributed allocation

    NARCIS (Netherlands)

    Chevaleyre, Y.; Endriss, U.; Maudet, N.; Padgham, L.; Parkes, D.; Müller, J.; Parsons, S.

    2008-01-01

    Distributed allocation mechanisms rely on the agents' autonomous (and supposedly rational) behaviour: states evolve as a result of agents contracting deals and exchanging resources. It is no surprise that restrictions on potential deals also restrict the reachability of some desirable states, for

  3. Multiobjective optimal allocation problem with probabilistic non ...

    African Journals Online (AJOL)

    This paper considers the optimum compromise allocation in multivariate stratified sampling with non-linear objective function and probabilistic non-linear cost constraint. The probabilistic non-linear cost constraint is converted into equivalent deterministic one by using Chance Constrained programming. A numerical ...

  4. Human Resource Subjects Allocation and Students' Academic ...

    African Journals Online (AJOL)

    This study investigated human resource subjects' allocation and students' academic performance in Secondary Schools in Obudu, Nigeria. The relevant variables of teachers subject was used as independent variable while the dependent variables were students' academic performance. Six hundred teachers from 20 ...

  5. FARM RESOURCE ALLOCATION AND PROFITABILITY OF ...

    African Journals Online (AJOL)

    Unique cropping systems have emerged in Nigeria to suit limited farmer resources and production objectives in humid forest inland valley ecosystems. But the basis for farm resource allocation and profitability of different crop enterprises are not properly understood. This study is based on a survey of 48 randomly selected ...

  6. Administrative Decision Making and Resource Allocation.

    Science.gov (United States)

    Sardy, Susan; Sardy, Hyman

    This paper considers selected aspects of the systems analysis of administrative decisionmaking regarding resource allocations in an educational system. A model of the instructional materials purchase system is presented. The major components of this model are: environment, input, decision process, conversion structure, conversion process, output,…

  7. Dynamic resource allocation using performance forecasting

    NARCIS (Netherlands)

    Moura, Paulo; Kon, Fabio; Voulgaris, Spyros; Van Steen, Maarten

    2016-01-01

    To benefit from the performance gains and cost savings enabled by elasticity in cloud IaaS environments, effective automated mechanisms for scaling are essential. This automation requires monitoring system status and defining criteria to trigger allocation and deallocation of resources. While these

  8. Resource Allocation Patterns and Student Achievement

    Science.gov (United States)

    James, Lori; Pate, James; Leech, Donald; Martin, Ellice; Brockmeier, Lantry; Dees, Elizabeth

    2011-01-01

    This quantitative research study was designed to examine the relationship between system resource allocation patterns and student achievement, as measured by eighth grade Criterion-Referenced Competency Test (CRCT) mathematics, eighth grade CRCT reading, eleventh grade Georgia High School Graduation Test (GHSGT) mathematics, eleventh grade and…

  9. 42 CFR 24.2 - Allocation.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Allocation. 24.2 Section 24.2 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES PERSONNEL SENIOR BIOMEDICAL RESEARCH SERVICE § 24... talent. (e) The Secretary will ensure that SBRS slots are used in support of high priority programs...

  10. Biased Allocation of Faces to Social Categories

    NARCIS (Netherlands)

    Dotsch, R.; Wigboldus, D.H.J.; Knippenberg, A.F.M. van

    2011-01-01

    Three studies show that social categorization is biased at the level of category allocation. In all studies, participants categorized faces. In Studies 1 and 2, participants overallocated faces with criminal features-a stereotypical negative trait-to the stigmatized Moroccan category, especially if

  11. Cooperation and profit allocation in distribution chains

    NARCIS (Netherlands)

    Guardiola, L.A.; Meca, A.; Timmer, Judith B.

    2005-01-01

    We study the coordination of actions and the allocation of profit in distribution chains under decentralized control. We consider distribution chains in which a single supplier supplies goods for replenishment of stocks of several retailers who, in turn, sell these goods to their own separate

  12. Cooperation and profit allocation in distribution chains

    NARCIS (Netherlands)

    Guardiola, Luis A.; Meca, Ana; Timmer, Judith B.

    2007-01-01

    We study the coordination of actions and the allocation of profit in supply chains under decentralized control in which a single supplier supplies several retailers with goods for replenishment of stocks. The goal of the supplier and the retailers is to maximize their individual profits. Since the

  13. Analysts' earnings forecasts and international asset allocation

    NARCIS (Netherlands)

    Huijgen, Carel; Plantinga, Auke

    1999-01-01

    The aim of this paper is to investigate whether financial analysts’ earnings forecasts are informative from the viewpoint of allocating investments across different stock markets. Therefore we develop a country forecast indicator reflecting the analysts’ prospects for specific stock markets. The

  14. Adaptive resource allocation for efficient patient scheduling

    NARCIS (Netherlands)

    Vermeulen, Ivan B.; Bohte, Sander M.; Elkhuizen, Sylvia G.; Lameris, Han; Bakker, Piet J. M.; La Poutré, Han

    2009-01-01

    Efficient scheduling of patient appointments on expensive resources is a complex and dynamic task. A resource is typically used by several patient groups. To service these groups, resource capacity is often allocated per group, explicitly or implicitly. Importantly, due to fluctuations in demand,

  15. Patient flow based allocation of hospital resources.

    Science.gov (United States)

    Vissers, J M

    1995-01-01

    The current practice of allocating resources within a hospital introduces peaks and troughs in the workloads of departments and leads therefore to loss of capacity. This happens when requirements for capacity coordination are not adequately taken into account in the decision making process of allocating resources to specialties. The first part of this research involved an analysis of the hospital's production system on dependencies between resources, resulting in a number of capacity coordination requirements that need to be fulfilled for optimized resource utilization. The second, modelling, part of the study involved the development of a framework for resource management decision making, of a set of computer models to support hospital managerial decision making on resource allocation issues in various parts of the hospital, and of an implementation strategy for the application of the models to concrete hospital settings. The third part of the study was devoted to a number of case-studies, illustrating the use of the models when applied in various resource management projects, such as a reorganization of an operating theatre timetable, or the development of a master plan for activities of a group of general surgeons serving two locations of a merged hospital system. The paper summarizes the main findings of the study and concludes with a discussion of results obtained with the new allocation procedure and with recommendations for future research.

  16. Issues in organ procurement, allocation, and transplantation.

    Science.gov (United States)

    Nierste, Deborah

    2013-01-01

    Organ transplantation extends lives and improves health but presents complex ethical dilemmas for nurses caring for donors, recipients, and their families. This article overviews organ procurement and allocation, discusses ethical dilemmas in transplantation, and offers strategies from professional and biblical perspectives for coping with moral distress and maintaining compassionate care.

  17. 15 CFR 923.110 - Allocation formula.

    Science.gov (United States)

    2010-01-01

    ... and comment. (f) Calculation of financial assistance award levels. Actual financial assistance award... matches any such grant according to the following ratios of Federal-to-state contributions for the...) Allocation formula factors and weighting. Each State eligible to receive a financial assistance award shall...

  18. Allocation of Cognitive Resources in Translation

    DEFF Research Database (Denmark)

    Hvelplund, Kristian Tangsgaard

    The present study is an empirical investigation of translators' allocation of cognitive resources during the translation process, and it aims at investigating how translators' mental processing resources are put to use during translation. The study bases ts analyses on quantitative eye...

  19. Axioms for health care resource allocation

    DEFF Research Database (Denmark)

    Østerdal, Lars Peter

    2005-01-01

    This paper examines principles of health care resource allocation based on axioms for individual preferences and distributive justice. We establish axioms for representing individual preferences by quality-adjusted life years (QALYs), as well as axioms for existence of a social welfare function...

  20. Financial Resource Allocation in Higher Education

    Science.gov (United States)

    Ušpuriene, Ana; Sakalauskas, Leonidas; Dumskis, Valerijonas

    2017-01-01

    The paper considers a problem of financial resource allocation in a higher education institution. The basic financial management instruments and the multi-stage cost minimization model created are described involving financial instruments to constraints. Both societal and institutional factors that determine the costs of educating students are…

  1. Spatial allocation of forest recreation value

    Science.gov (United States)

    Kenneth A. Baerenklau; Armando Gonzalez-Caban; Catrina Paez; Edgard Chavez

    2009-01-01

    Non-market valuation methods and geographic information systems are useful planning and management tools for public land managers. Recent attention has been given to investigation and demonstration of methods for combining these tools to provide spatially-explicit representations of non-market value. Most of these efforts have focused on spatial allocation of...

  2. Capital Allocation Effects of Financial Reporting Regulation

    NARCIS (Netherlands)

    Koenigsgruber, R.

    2012-01-01

    This paper analyses the effects of stricter financial reporting enforcement on capital allocation and reporting quality in a game-theoretic model and derives conclusions about optimal enforcement strictness. Analysis of the model shows that reporting quality strictly increases with tighter

  3. Tracking the allocation of attention using human pupillary oscillations

    Directory of Open Access Journals (Sweden)

    Marnix eNaber

    2013-12-01

    Full Text Available The muscles that control the pupil are richly innervated by the autonomic nervous system. While there are central pathways that drive pupil dilations in relation to arousal, there is no anatomical evidence that cortical centers involved with visual selective attention innervate the pupil. In this study, we show that such connections must exist. Specifically, we demonstrate a novel Pupil Frequency Tagging (PFT method, where oscillatory changes in stimulus brightness over time are mirrored by pupil constrictions and dilations. We find that the luminance induced pupil oscillations are enhanced when covert attention is directed to the flicker stimulus and when targets are correctly detected in an attentional tracking task. These results suggest that the amplitudes of pupil responses closely follow the allocation of focal visual attention and the encoding of stimuli. PFT provides a new opportunity to study top down visual attention itself as well as identifying the pathways and mechanisms that support this unexpected phenomenon.

  4. Parametric spectro-temporal analyzer (PASTA) for real-time optical spectrum observation

    Science.gov (United States)

    Zhang, Chi; Xu, Jianbing; Chui, P. C.; Wong, Kenneth K. Y.

    2013-06-01

    Real-time optical spectrum analysis is an essential tool in observing ultrafast phenomena, such as the dynamic monitoring of spectrum evolution. However, conventional method such as optical spectrum analyzers disperse the spectrum in space and allocate it in time sequence by mechanical rotation of a grating, so are incapable of operating at high speed. A more recent method all-optically stretches the spectrum in time domain, but is limited by the allowable input condition. In view of these constraints, here we present a real-time spectrum analyzer called parametric spectro-temporal analyzer (PASTA), which is based on the time-lens focusing mechanism. It achieves a frame rate as high as 100 MHz and accommodates various input conditions. As a proof of concept and also for the first time, we verify its applications in observing the dynamic spectrum of a Fourier domain mode-locked laser, and the spectrum evolution of a laser cavity during its stabilizing process.

  5. The Spectrum of Wind Power Fluctuations

    Science.gov (United States)

    Bandi, Mahesh

    2016-11-01

    Wind is a variable energy source whose fluctuations threaten electrical grid stability and complicate dynamical load balancing. The power generated by a wind turbine fluctuates due to the variable wind speed that blows past the turbine. Indeed, the spectrum of wind power fluctuations is widely believed to reflect the Kolmogorov spectrum; both vary with frequency f as f - 5 / 3. This variability decreases when aggregate power fluctuations from geographically distributed wind farms are averaged at the grid via a mechanism known as geographic smoothing. Neither the f - 5 / 3 wind power fluctuation spectrum nor the mechanism of geographic smoothing are understood. In this work, we explain the wind power fluctuation spectrum from the turbine through grid scales. The f - 5 / 3 wind power fluctuation spectrum results from the largest length scales of atmospheric turbulence of order 200 km influencing the small scales where individual turbines operate. This long-range influence spatially couples geographically distributed wind farms and synchronizes farm outputs over a range of frequencies and decreases with increasing inter-farm distance. Consequently, aggregate grid-scale power fluctuations remain correlated, and are smoothed until they reach a limiting f - 7 / 3 spectrum. This work was funded by the Collective Interactions Unit, OIST Graduate University, Japan.

  6. A Unified Framework for the Ergodic Capacity of Spectrum Sharing Cognitive Radio Systems

    KAUST Repository

    Sboui, Lokman

    2012-12-29

    We consider a spectrum sharing communication scenario in which a primary and a secondary users are communicating, simultaneously, with their respective destinations using the same frequency carrier. Both optimal power profile and ergodic capacity are derived for fading channels, under an average transmit power and an instantaneous interference outage constraints. Unlike previous studies, we assume that the secondary user has a noisy version of the cross link and the secondary link Channel State Information (CSI). After deriving the capacity in this case, we provide an ergodic capacity generalization, through a unified expression, that encompasses several previously studied spectrum sharing settings. In addition, we provide an asymptotic capacity analysis at high and low signal-to-noise ratio (SNR). Numerical results, applied for independent Rayleigh fading channels, show that at low SNR regime, only the secondary channel estimation matters with no effect of the cross link on the capacity; whereas at high SNR regime, the capacity is rather driven by the cross link CSI. Furthermore, a practical on-off power allocation scheme is proposed and is shown, through numerical results, to achieve the full capacity at high and low SNR regimes and suboptimal rates in the medium SNR regime.

  7. Study of a new technique for measuring the travel time of ultrasonic waves using the frequency spectrum; Estudo de uma nova tecnica de medida do tempo de percurso da onda ultra-sonica usando o espectro de frequencia

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Allan Xavier dos

    2010-07-01

    During the operation of a nuclear plant and other industrial plants, the operational time and the exposition to severe working conditions may cause the wear of its components, consequently, compromising the safety and the performance of the installation. The implementation of periodical inspections helps to ensure the safe operation and the best performance of the plant. In this way, the use of ultrasonic techniques for inspection and materials characterization becomes more and more attractive, since they offer quick, precise results and are technically ease to implement. The usual ultrasonic techniques, need to the measure the travelling time of the ultrasonic wave in the material examined in order to extract information useful to characterize it. Thus, the measurement of the travelling time of the ultrasonic wave is the overriding factor in most of the applications made with ultrasound. In this work a new technique was developed for measuring the travelling time of the ultrasonic wave using a Fourier's Fast Transformer (FFT). It will be shown mathematically and experimentally that it is possible to use the ultrasonic signal in the frequency domain to determine the travelling time of the ultrasonic wave. Five experiments were carried out for the experimental validation of this new technique. The materials used were 20 ceramic pastilles with different porosities and 3 aluminum plates of different thicknesses. The obtained results have shown that the new technique proposed in this work was able to determine the travelling time of the ultrasonic wave with the same precision as the conventional technique. It was shown, furthermore, that this new technique is able to measure the travelling time of the ultrasonic wave in situations where the conventional technique cannot be applied greatly expanding the range of application of ultrasonic testing and inspections. (author)

  8. Influence of the matrix composition in the Emission spectroscopic analysis of solutions with continuous nebulization of the sample and excitation of the spectrum in a high-frequency inductively coupled plasma discharge

    International Nuclear Information System (INIS)

    Zil'bershtein, K.I.; Kartasheva, M.A.; Mushkovich, G.N.

    1986-01-01

    Numerous investigations have shown that the emission spectroscopic analysis of solutions with the use of a high-frequency inductively coupled plasma discharge is characterized by the absence of an influence or the presence of a small influence of the matrix elements on the amplitudes of the analytical signals of the elements being determined and, consequently, on the results of an analysis. The influences of the first type include the influences of easily ionized elements, which, as we know, are very significant in spectroscopic analysis with the use of traditional sources for the excitation of the spectra (arcs, sparks, and flames). The influences of the second type include, in particular, the influences associated with changes in the viscosity and surface tension of the solutions as the concentration of the matrix elements in the solutions is increased. In order to obtain correct results from an analysis in the case of spectral interference, special methods for treating the spectra are used for the purpose of taking into account the background and the instances of superposition and establishing the true (''pure'') intensity of the analytical lines. Results are shown of the Determination of impurities in aqueous solutions of sodium Molybate Single Crystals (the concentration of Na 2 Mo 2 O 7 in the solution was 1 mg/ml). When the solutions being analyzed are diluted to a concentration of Na 2 Mo 2 O 7 equal to 1 mg/ml, good agreement between the results of the determination of vanadium (and other impurities) obtained with the use of reference solutions not containing the matrix elements and the results obtained with the use of reference solutions containing the matrix elements in the same concentrations as in the solutions being analyzed (1mg/ml) was guaranteed

  9. Laser Spectroscopy and Frequency Combs

    International Nuclear Information System (INIS)

    Hänsch, Theodor W; Picqué, Nathalie

    2013-01-01

    The spectrum of a frequency comb, commonly generated by a mode-locked femtosecond laser consists of several hundred thousand precisely evenly spaced spectral lines. Such laser frequency combs have revolutionized the art measuring the frequency of light, and they provide the long-missing clockwork for optical atomic clocks. The invention of the frequency comb technique has been motivated by precision laser spectroscopy of the simple hydrogen atom. The availability of commercial instruments is facilitating the evolution of new applications far beyond the original purpose. Laser combs are becoming powerful instruments for broadband molecular spectroscopy by dramatically improving the resolution and recording speed of Fourier spectrometers and by creating new opportunities for highly multiplexed nonlinear spectroscopy, such as two-photon spectroscopy or coherent Raman spectroscopy. Other emerging applications of frequency combs range from fundamental research in astronomy, chemistry, or attosecond science to telecommunications and satellite navigation

  10. Bandwidth and power allocation for two-way relaying in overlay cognitive radio systems

    KAUST Repository

    Alsharoa, Ahmad M.

    2014-12-01

    In this paper, the problem of both bandwidth and power allocation for two-way multiple relay systems in overlay cognitive radio (CR) setup is investigated. In the CR overlay mode, primary users (PUs) cooperate with cognitive users (CUs) for mutual benefits. In our framework, we propose that the CUs are allowed to allocate a part of the PUs spectrum to perform their cognitive transmission. In return, acting as an amplify-and-forward two-way relays, they are used to support PUs to achieve their target data rates over the remaining bandwidth. More specifically, CUs acts as relays for the PUs and gain some spectrum as long as they respect a specific power budget and primary quality-of-service constraints. In this context, we first derive closed-form expressions for optimal transmit power allocated to PUs and CUs in order to maximize the cognitive objective. Then, we employ a strong optimization tool based on particle swarm optimization algorithm to find the optimal relay amplification gains and optimal cognitive released bandwidths as well. Our numerical results illustrate the performance of our proposed algorithm for different utility metrics and analyze the impact of some system parameters on the achieved performance.

  11. The continuous wave NQR spectrometer with equidistant frequency scale

    Directory of Open Access Journals (Sweden)

    Samila A. P.

    2010-10-01

    Full Text Available The phase binding frequency of marginal oscillator to frequency synthesizer which includes a phase detector, are used for linearization of the frequency sweep. For spectrum calibration the circuit is designed which forms «scale rule» of the frequency tags with an interval of 10 and 100 kHz.

  12. Assessing the effects of adaptation measures on optimal water resources allocation under varied water availability conditions

    Science.gov (United States)

    Liu, Dedi; Guo, Shenglian; Shao, Quanxi; Liu, Pan; Xiong, Lihua; Wang, Le; Hong, Xingjun; Xu, Yao; Wang, Zhaoli

    2018-01-01

    Human activities and climate change have altered the spatial and temporal distribution of water availability which is a principal prerequisite for allocation of different water resources. In order to quantify the impacts of climate change and human activities on water availability and optimal allocation of water resources, hydrological models and optimal water resource allocation models should be integrated. Given that increasing human water demand and varying water availability conditions necessitate adaptation measures, we propose a framework to assess the effects of these measures on optimal allocation of water resources. The proposed model and framework were applied to a case study of the middle and lower reaches of the Hanjiang River Basin in China. Two representative concentration pathway (RCP) scenarios (RCP2.6 and RCP4.5) were employed to project future climate, and the Variable Infiltration Capacity (VIC) hydrological model was used to simulate the variability of flows under historical (1956-2011) and future (2012-2099) conditions. The water availability determined by simulating flow with the VIC hydrological model was used to establish the optimal water resources allocation model. The allocation results were derived under an extremely dry year (with an annual average water flow frequency of 95%), a very dry year (with an annual average water flow frequency of 90%), a dry year (with an annual average water flow frequency of 75%), and a normal year (with an annual average water flow frequency of 50%) during historical and future periods. The results show that the total available water resources in the study area and the inflow of the Danjiangkou Reservoir will increase in the future. However, the uneven distribution of water availability will cause water shortage problems, especially in the boundary areas. The effects of adaptation measures, including water saving, and dynamic control of flood limiting water levels (FLWLs) for reservoir operation, were

  13. Frequency spirals

    International Nuclear Information System (INIS)

    Ottino-Löffler, Bertrand; Strogatz, Steven H.

    2016-01-01

    We study the dynamics of coupled phase oscillators on a two-dimensional Kuramoto lattice with periodic boundary conditions. For coupling strengths just below the transition to global phase-locking, we find localized spatiotemporal patterns that we call “frequency spirals.” These patterns cannot be seen under time averaging; they become visible only when we examine the spatial variation of the oscillators' instantaneous frequencies, where they manifest themselves as two-armed rotating spirals. In the more familiar phase representation, they appear as wobbly periodic patterns surrounding a phase vortex. Unlike the stationary phase vortices seen in magnetic spin systems, or the rotating spiral waves seen in reaction-diffusion systems, frequency spirals librate: the phases of the oscillators surrounding the central vortex move forward and then backward, executing a periodic motion with zero winding number. We construct the simplest frequency spiral and characterize its properties using analytical and numerical methods. Simulations show that frequency spirals in large lattices behave much like this simple prototype.

  14. Frequency spirals

    Energy Technology Data Exchange (ETDEWEB)

    Ottino-Löffler, Bertrand; Strogatz, Steven H., E-mail: strogatz@cornell.edu [Center for Applied Mathematics, Cornell University, Ithaca, New York 14853 (United States)

    2016-09-15

    We study the dynamics of coupled phase oscillators on a two-dimensional Kuramoto lattice with periodic boundary conditions. For coupling strengths just below the transition to global phase-locking, we find localized spatiotemporal patterns that we call “frequency spirals.” These patterns cannot be seen under time averaging; they become visible only when we examine the spatial variation of the oscillators' instantaneous frequencies, where they manifest themselves as two-armed rotating spirals. In the more familiar phase representation, they appear as wobbly periodic patterns surrounding a phase vortex. Unlike the stationary phase vortices seen in magnetic spin systems, or the rotating spiral waves seen in reaction-diffusion systems, frequency spirals librate: the phases of the oscillators surrounding the central vortex move forward and then backward, executing a periodic motion with zero winding number. We construct the simplest frequency spiral and characterize its properties using analytical and numerical methods. Simulations show that frequency spirals in large lattices behave much like this simple prototype.

  15. Multimedia transmission in MC-CDMA using adaptive subcarrier power allocation and CFO compensation

    Science.gov (United States)

    Chitra, S.; Kumaratharan, N.

    2018-02-01

    Multicarrier code division multiple access (MC-CDMA) system is one of the most effective techniques in fourth-generation (4G) wireless technology, due to its high data rate, high spectral efficiency and resistance to multipath fading. However, MC-CDMA systems are greatly deteriorated by carrier frequency offset (CFO) which is due to Doppler shift and oscillator instabilities. It leads to loss of orthogonality among the subcarriers and causes intercarrier interference (ICI). Water filling algorithm (WFA) is an efficient resource allocation algorithm to solve the power utilisation problems among the subcarriers in time-dispersive channels. The conventional WFA fails to consider the effect of CFO. To perform subcarrier power allocation with reduced CFO and to improve the capacity of MC-CDMA system, residual CFO compensated adaptive subcarrier power allocation algorithm is proposed in this paper. The proposed technique allocates power only to subcarriers with high channel to noise power ratio. The performance of the proposed method is evaluated using random binary data and image as source inputs. Simulation results depict that the bit error rate performance and ICI reduction capability of the proposed modified WFA offered superior performance in both power allocation and image compression for high-quality multimedia transmission in the presence of CFO and imperfect channel state information conditions.

  16. Dynamic Subcarrier Allocation for Real-Time Traffic over Multiuser OFDM Systems

    Directory of Open Access Journals (Sweden)

    Li VictorOK

    2009-01-01

    Full Text Available A dynamic resource allocation algorithm to satisfy the packet delay requirements for real-time services, while maximizing the system capacity in multiuser orthogonal frequency division multiplexing (OFDM systems is introduced. Our proposed cross-layer algorithm, called Dynamic Subcarrier Allocation algorithm for Real-time Traffic (DSA-RT, consists of two interactive components. In the medium access control (MAC layer, the users' expected transmission rates in terms of the number of subcarriers per symbol and their corresponding transmission priorities are evaluated. With the above MAC-layer information and the detected subcarriers' channel gains, in the physical (PHY layer, a modified Kuhn-Munkres algorithm is developed to minimize the system power for a certain subcarrier allocation, then a PHY-layer resource allocation scheme is proposed to optimally allocate the subcarriers under the system signal-to-noise ratio (SNR and power constraints. In a system where the number of mobile users changes dynamically, our developed MAC-layer access control and removal schemes can guarantee the quality of service (QoS of the existing users in the system and fully utilize the bandwidth resource. The numerical results show that DSA-RT significantly improves the system performance in terms of the bandwidth efficiency and delay performance for real-time services.

  17. A novel power and offset allocation method for spatial multiplexing MIMO Systems in optical wireless channels

    KAUST Repository

    Park, Kihong

    2011-12-01

    We consider optical wireless communication which can be utilized for illumination and communication by relying on lighting devices. Due to the limited bandwidth of optical sources, it is challenging to achieve high data rate in optical wireless systems. In order to obtain a multiplexing gain and high spectral efficiency, we design an optical multi-input multi-output (MIMO) system utilizing a singular value decomposition-based spatial multiplexing and adaptive modulation. We note that the conventional allocation method in radio frequency MIMO channels cannot be applied directly to the optical intensity channels. In this paper, we generalize the result of power allocation method in [1] for arbitrary number of transmit and receive antennas in optical wireless MIMO systems. Based on three constraints, namely, the nonnegativity, the aggregate optical power, and the bit error rate requirement, we propose a novel method to allocate the optical power, the offset value, and the modulation size for maximum sum rate. From some selected simulation results, we show that our proposed allocation method gives a better spectral efficiency than the method that allocates the optical power equally for each data stream. © 2011 IEEE.

  18. Josephson junction spectrum analyzer for millimeter and submillimeter wavelengths

    International Nuclear Information System (INIS)

    Larkin, S.Y.; Anischenko, S.E.; Khabayev, P.V.

    1994-01-01

    A prototype of the Josephson-effect spectrum analyzer developed for the millimeter-wave band is described. The measurement results for spectra obtained in the frequency band from 50 to 250 GHz are presented

  19. Josephson junction spectrum analyzer for millimeter and submillimeter wavelengths

    Energy Technology Data Exchange (ETDEWEB)

    Larkin, S.Y.; Anischenko, S.E.; Khabayev, P.V. [State Research Center, Kiev (Ukraine)

    1994-12-31

    A prototype of the Josephson-effect spectrum analyzer developed for the millimeter-wave band is described. The measurement results for spectra obtained in the frequency band from 50 to 250 GHz are presented.

  20. Distributed Channel Allocation and Time Slot Optimization for Green Internet of Things

    Directory of Open Access Journals (Sweden)

    Kaiqi Ding

    2017-10-01

    Full Text Available In sustainable smart cities, power saving is a severe challenge in the energy-constrained Internet of Things (IoT. Efficient utilization of limited multiple non-overlap channels and time resources is a promising solution to reduce the network interference and save energy consumption. In this paper, we propose a joint channel allocation and time slot optimization solution for IoT. First, we propose a channel ranking algorithm which enables each node to rank its available channels based on the channel properties. Then, we propose a distributed channel allocation algorithm so that each node can choose a proper channel based on the channel ranking and its own residual energy. Finally, the sleeping duration and spectrum sensing duration are jointly optimized to maximize the normalized throughput and satisfy energy consumption constraints simultaneously. Different from the former approaches, our proposed solution requires no central coordination or any global information that each node can operate based on its own local information in a total distributed manner. Also, theoretical analysis and extensive simulations have validated that when applying our solution in the network of IoT: (i each node can be allocated to a proper channel based on the residual energy to balance the lifetime; (ii the network can rapidly converge to a collision-free transmission through each node’s learning ability in the process of the distributed channel allocation; and (iii the network throughput is further improved via the dynamic time slot optimization.

  1. Distributed Channel Allocation and Time Slot Optimization for Green Internet of Things.

    Science.gov (United States)

    Ding, Kaiqi; Zhao, Haitao; Hu, Xiping; Wei, Jibo

    2017-10-28

    In sustainable smart cities, power saving is a severe challenge in the energy-constrained Internet of Things (IoT). Efficient utilization of limited multiple non-overlap channels and time resources is a promising solution to reduce the network interference and save energy consumption. In this paper, we propose a joint channel allocation and time slot optimization solution for IoT. First, we propose a channel ranking algorithm which enables each node to rank its available channels based on the channel properties. Then, we propose a distributed channel allocation algorithm so that each node can choose a proper channel based on the channel ranking and its own residual energy. Finally, the sleeping duration and spectrum sensing duration are jointly optimized to maximize the normalized throughput and satisfy energy consumption constraints simultaneously. Different from the former approaches, our proposed solution requires no central coordination or any global information that each node can operate based on its own local information in a total distributed manner. Also, theoretical analysis and extensive simulations have validated that when applying our solution in the network of IoT: (i) each node can be allocated to a proper channel based on the residual energy to balance the lifetime; (ii) the network can rapidly converge to a collision-free transmission through each node's learning ability in the process of the distributed channel allocation; and (iii) the network throughput is further improved via the dynamic time slot optimization.

  2. Auction-Based Resource Allocation for Cooperative Video Transmission Protocols over Wireless Networks

    Directory of Open Access Journals (Sweden)

    Zhu Han

    2009-01-01

    Full Text Available Cooperative transmission has been proposed as a novel transmission strategy that takes advantage of broadcast nature of wireless networks, forms virtual MIMO system, and provides diversity gains. In this paper, wireless video transmission protocols are proposed, in which the spectrum resources are first allocated for the source side to broadcast video packets to the relay and destination, and then for the relay side to transmit side information generated from the received packets. The proposed protocols are optimized to minimize the end-to-end expected distortion via choosing bandwidth/power allocation, configuration of side information, subject to bandwidth and power constraints. For multiuser cases, most of current resource allocation approaches cannot be naturally extended and applied to the networks with relay nodes for video transmission. This paper extends the share auction approach into the cooperative video communication scenarios and provides a near-optimal solution for resource allocation. Experimental results have demonstrated that the proposed approach has significant advantage of up to 4 dB gain in single user case and 1.3 dB gain in multiuser case over the reference systems in terms of peak-to-signal-noise ratio. In addition, it reduces the formidable computational complexity of the optimal solution to linear complexity with performance degradation of less than 0.3 dB.

  3. Allocating effort and anticipating pleasure in schizophrenia: Relationship with real world functioning.

    Science.gov (United States)

    Serper, M; Payne, E; Dill, C; Portillo, C; Taliercio, J

    2017-10-01

    Poor motivation to engage in goal-oriented behavior has been recognized as a hallmark feature of schizophrenia spectrum disorders (SZ). Low drive in SZ may be related to anticipating rewards as well as to poor working memory. However, few studies to date have examined beliefs about self-efficacy and satisfaction for future rewards (anticipatory pleasure). Additionally, few studies to date have examined how these deficits may impact SZ patients' real world functioning. The present study examined SZ patients' (n=57) anticipatory pleasure, working memory, self-efficacy and real world functioning in relation to their negative symptom severity. Results revealed that SZ patients' negative symptom severity was related to decisions in effort allocation and reward probability, working memory deficits, self-efficacy and anticipatory pleasure for future reward. Effort allocation deficits also predicted patients' daily functioning skills. SZ patients with high levels of negative symptoms are not merely effort averse, but have more difficulty effectively allocating effort and anticipating pleasure engaging in effortful activities. It may be the case that continuously failing to achieve reinforcement from engagement and participation may lead SZ patients to form certain negative beliefs about their abilities which contributes to amotivation and cognitive deficits. Lastly, our findings provide further support for a link between SZ patients functional daily living skills their effort allocation. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  4. Risk allocation in independent power supply contracts

    International Nuclear Information System (INIS)

    Willrich, M.; Campbell, W.L.

    1992-01-01

    Congress has made significant progress in recent months toward amending the Public Utility Holding Company Act of 1935 (PUHCA). The purposes of such amendment are to broaden power supply options for electric utilities and expand competition in whole-sale power generation markets. PUHCA reform is an integral part of President Bush's National Energy Strategy and has been included in legislation pending in both Houses of Congress. Congress will, hopefully, approve energy legislation that includes PUHCA reform before it adjourns this year. PUHCA reform has, however, stimulated heated debate within the power industry itself as well as among various consumer interest groups. One important issue in the public debate concerns risk allocation. If PUHCA is reformed, will risk be allocated efficiently and equitably between independent power producers and electric utility buyers? This article addresses that important question

  5. Using contests to allocate pollution rights

    International Nuclear Information System (INIS)

    MacKenzie, Ian A.; Hanley, Nick; Kornienko, Tatiana

    2009-01-01

    In this paper we advocate a new initial allocation mechanism for a tradable pollution permit market. We outline a Permit Allocation Contest (PAC) that distributes permits to firms based on their rank relative to other firms. This ranking is achieved by ordering firms based on an observable 'external action' where the external action is an activity or characteristic of the firm that is independent of their choice of emissions in the tradable permit market. We argue that this mechanism has a number of benefits over auctioning and grandfathering. Using this mechanism efficiently distributes permits, allows for the attainment of a secondary policy objective and has the potential to be more politically appealing than existing alternatives.

  6. The dynamics of farm land allocation

    DEFF Research Database (Denmark)

    Arnberg, Søren; Hansen, Lars Gårn

    This study develops a dynamic multi-output model of farmers’ crop allocation decisions that allows estimation of both short-run and long-run adjustments to a wide array of economic incentives. The method can be used to inform decision-makers about a number of issues including agricultural policy...... reform and environmental regulation. The model allows estimation of dynamic effects relating to price expectations adjustment, investment lags and crop rotation constraints. Estimation is based on micro-panel data from Danish farmers that includes acreage, output and variable input utilisation...... at the crop level. Results indicate that there are substantial differences between the shortrun and long-run land allocation behaviour of Danish farmers and that there are substantial differences in the time lags associated with different crops. Since similar farming conditions are found in northern Europe...

  7. Fund Allocation in Complex Rehabilitation Programs

    Directory of Open Access Journals (Sweden)

    Tarek Hegazy

    2013-12-01

    Full Text Available Civil Infrastructure assets require continuous renewal actions to sustain their operability and safety. Allocating limited renewal funds amongst numerous building components, however, represents a large-scale optimization problem and earlier efforts utilized genetic algorithms (GAs to optimize medium size problems yet exhibit steep performance degradation as problem size increases. In this research, after experimenting with various approaches of segmenting a large problem into multiple smaller sub-problems, clustered segmentation proved to be the most promising. The paper discusses the underlying life cycle analysis model, the various segmentation methods, and the optimization results using the improved GAs + clustered segmentation, which proved to be able to optimize asset renewals for 50,000 components with no noticeable performance degradation. The proposed method is simple and logical, and can be used on variety of asset types to improve infrastructure fund allocation. Future extension of this research is then highlighted.

  8. Adolescence, Attention Allocation, and Driving Safety

    OpenAIRE

    Romer, Daniel; Lee, Yi-Ching; McDonald, Catherine C.; Winston, Flaura K.

    2014-01-01

    Motor vehicle crashes are the leading source of morbidity and mortality in adolescents in the United States and the developed world. Inadequate allocation of attention to the driving task and to driving hazards are important sources of adolescent crashes. We review major explanations for these attention failures with particular focus on the roles that brain immaturity and lack of driving experience play in causing attention problems. The review suggests that the potential for overcoming inexp...

  9. Nonparametric correlation models for portfolio allocation

    DEFF Research Database (Denmark)

    Aslanidis, Nektarios; Casas, Isabel

    2013-01-01

    This article proposes time-varying nonparametric and semiparametric estimators of the conditional cross-correlation matrix in the context of portfolio allocation. Simulations results show that the nonparametric and semiparametric models are best in DGPs with substantial variability or structural ...... currencies. Results show the nonparametric model generally dominates the others when evaluating in-sample. However, the semiparametric model is best for out-of-sample analysis....

  10. Rethinking Reinforcement: Allocation, Induction, and Contingency

    Science.gov (United States)

    Baum, William M

    2012-01-01

    The concept of reinforcement is at least incomplete and almost certainly incorrect. An alternative way of organizing our understanding of behavior may be built around three concepts: allocation, induction, and correlation. Allocation is the measure of behavior and captures the centrality of choice: All behavior entails choice and consists of choice. Allocation changes as a result of induction and correlation. The term induction covers phenomena such as adjunctive, interim, and terminal behavior—behavior induced in a situation by occurrence of food or another Phylogenetically Important Event (PIE) in that situation. Induction resembles stimulus control in that no one-to-one relation exists between induced behavior and the inducing event. If one allowed that some stimulus control were the result of phylogeny, then induction and stimulus control would be identical, and a PIE would resemble a discriminative stimulus. Much evidence supports the idea that a PIE induces all PIE-related activities. Research also supports the idea that stimuli correlated with PIEs become PIE-related conditional inducers. Contingencies create correlations between “operant” activity (e.g., lever pressing) and PIEs (e.g., food). Once an activity has become PIE-related, the PIE induces it along with other PIE-related activities. Contingencies also constrain possible performances. These constraints specify feedback functions, which explain phenomena such as the higher response rates on ratio schedules in comparison with interval schedules. Allocations that include a lot of operant activity are “selected” only in the sense that they generate more frequent occurrence of the PIE within the constraints of the situation; contingency and induction do the “selecting.” PMID:22287807

  11. Allocating nuclear power plant costs: an extension

    International Nuclear Information System (INIS)

    Bierman, H. Jr.

    1984-01-01

    The author modifies and extends the argument presented in the September 22, 1983 issue by Richard E. Nellis for using economic depreciation to allocate nuclear power plant costs. The two goals of his model are to charge constant real costs to consumers and to provide a fair return of .125 to investors in each period. The addition of other objectives requires further modification of the model since the schedule of revenues that are deemed to be optimum defines the depreciation schedule. 1 table

  12. Millimeter wave spectrum of nitromethane

    Science.gov (United States)

    Ilyushin, Vadim

    2018-03-01

    A new study of the millimeter wave spectrum of nitromethane, CH3NO2, is reported. The new measurements covering the frequency range from 49 GHz to 237 GHz have been carried out using the spectrometer in IRA NASU (Ukraine). Transitions belonging to the |m| ≤ 8 torsional states have been analyzed using the Rho-axis-method and the RAM36 program, which has been modified for this study to take into account the quadrupole hyperfine structure due to presence of the nitrogen atom. A data set consisting of 5925 microwave line frequencies and including transitions with J up to 55 was fit using a model consisting of 97 parameters, and a weighted root-mean-square deviation of 0.84 was achieved. The analysis of the spectrum covers the m torsional states lying below the lowest small amplitude vibration in nitromethane molecule, which is the NO2 in plane rock at 475 cm-1. It serves as a preparatory step in further studies of intervibrational interactions in this molecule.

  13. A Channel Allocation Mechanism for Cellular Networks

    Directory of Open Access Journals (Sweden)

    Chi-Hua Chen

    2017-04-01

    Full Text Available In cellular networks, call blocking causes lower customer satisfaction and economic loss. Therefore, the channel allocation for call block avoidance is an important issue. This study proposes a mechanism that considers the real-time traffic information (e.g., traffic flow and vehicle speed and the user behavior (e.g., call inter-arrival time and call holding time to analyze the adaptable number of communication calls in the specific cell for channel allocation. In experiments about call block probabilities (CBP, this study simulated two cases that are the situations of the whole day and traffic accident. The simulation results show that all CBPs in the scenario of whole day are less than 21.5% by using the proposed mechanism, which is better than using the static channel allocation (SCA mechanism. Moreover, all CBPs in the scenario of traffic accidents are less than 16.5% by using the proposed mechanism, which is better than using the SCA mechanism. Therefore, the proposed mechanism can decrease the number of CBPs effectively.

  14. Irrational time allocation in decision-making.

    Science.gov (United States)

    Oud, Bastiaan; Krajbich, Ian; Miller, Kevin; Cheong, Jin Hyun; Botvinick, Matthew; Fehr, Ernst

    2016-01-13

    Time is an extremely valuable resource but little is known about the efficiency of time allocation in decision-making. Empirical evidence suggests that in many ecologically relevant situations, decision difficulty and the relative reward from making a correct choice, compared to an incorrect one, are inversely linked, implying that it is optimal to use relatively less time for difficult choice problems. This applies, in particular, to value-based choices, in which the relative reward from choosing the higher valued item shrinks as the values of the other options get closer to the best option and are thus more difficult to discriminate. Here, we experimentally show that people behave sub-optimally in such contexts. They do not respond to incentives that favour the allocation of time to choice problems in which the relative reward for choosing the best option is high; instead they spend too much time on problems in which the reward difference between the options is low. We demonstrate this by showing that it is possible to improve subjects' time allocation with a simple intervention that cuts them off when their decisions take too long. Thus, we provide a novel form of evidence that organisms systematically spend their valuable time in an inefficient way, and simultaneously offer a potential solution to the problem. © 2016 The Author(s).

  15. Optimal allocation of trend following strategies

    Science.gov (United States)

    Grebenkov, Denis S.; Serror, Jeremy

    2015-09-01

    We consider a portfolio allocation problem for trend following (TF) strategies on multiple correlated assets. Under simplifying assumptions of a Gaussian market and linear TF strategies, we derive analytical formulas for the mean and variance of the portfolio return. We construct then the optimal portfolio that maximizes risk-adjusted return by accounting for inter-asset correlations. The dynamic allocation problem for n assets is shown to be equivalent to the classical static allocation problem for n2 virtual assets that include lead-lag corrections in positions of TF strategies. The respective roles of asset auto-correlations and inter-asset correlations are investigated in depth for the two-asset case and a sector model. In contrast to the principle of diversification suggesting to treat uncorrelated assets, we show that inter-asset correlations allow one to estimate apparent trends more reliably and to adjust the TF positions more efficiently. If properly accounted for, inter-asset correlations are not deteriorative but beneficial for portfolio management that can open new profit opportunities for trend followers. These concepts are illustrated using daily returns of three highly correlated futures markets: the E-mini S&P 500, Euro Stoxx 50 index, and the US 10-year T-note futures.

  16. Biomass Resource Allocation among Competing End Uses

    Energy Technology Data Exchange (ETDEWEB)

    Newes, E.; Bush, B.; Inman, D.; Lin, Y.; Mai, T.; Martinez, A.; Mulcahy, D.; Short, W.; Simpkins, T.; Uriarte, C.; Peck, C.

    2012-05-01

    The Biomass Scenario Model (BSM) is a system dynamics model developed by the U.S. Department of Energy as a tool to better understand the interaction of complex policies and their potential effects on the biofuels industry in the United States. However, it does not currently have the capability to account for allocation of biomass resources among the various end uses, which limits its utilization in analysis of policies that target biomass uses outside the biofuels industry. This report provides a more holistic understanding of the dynamics surrounding the allocation of biomass among uses that include traditional use, wood pellet exports, bio-based products and bioproducts, biopower, and biofuels by (1) highlighting the methods used in existing models' treatments of competition for biomass resources; (2) identifying coverage and gaps in industry data regarding the competing end uses; and (3) exploring options for developing models of biomass allocation that could be integrated with the BSM to actively exchange and incorporate relevant information.

  17. Resource allocation models of auditory working memory.

    Science.gov (United States)

    Joseph, Sabine; Teki, Sundeep; Kumar, Sukhbinder; Husain, Masud; Griffiths, Timothy D

    2016-06-01

    Auditory working memory (WM) is the cognitive faculty that allows us to actively hold and manipulate sounds in mind over short periods of time. We develop here a particular perspective on WM for non-verbal, auditory objects as well as for time based on the consideration of possible parallels to visual WM. In vision, there has been a vigorous debate on whether WM capacity is limited to a fixed number of items or whether it represents a limited resource that can be allocated flexibly across items. Resource allocation models predict that the precision with which an item is represented decreases as a function of total number of items maintained in WM because a limited resource is shared among stored objects. We consider here auditory work on sequentially presented objects of different pitch as well as time intervals from the perspective of dynamic resource allocation. We consider whether the working memory resource might be determined by perceptual features such as pitch or timbre, or bound objects comprising multiple features, and we speculate on brain substrates for these behavioural models. This article is part of a Special Issue entitled SI: Auditory working memory. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Transnational Energy Companies' Investment Allocation Decisions

    International Nuclear Information System (INIS)

    Osmundsen, Petter; Emhjellen, Magne; Halleraker, Morten

    2001-10-01

    When making international capital budgeting decisions, energy companies are often faced with capital and organisational constraints. The constraints may be real or management imposed. In addition, when entering into a new country or region the companies will incur fixed new area costs that must be considered before investment approval. The decision problem is therefore not a linear problem where the standard net present value rule applies, but a non-linear problem of selecting the combination of projects with the maximum aggregate net present value. New project investments will therefore be selected based on the size of the net present value (often referred to as financial volume or materiality) compared to the projects' use of capital and scarce personnel and organisational capacity. Consequently, projects with a positive net present value, but with low materiality, may not be approved. The portfolio choice has a parallel to the company's choice of core areas. Instead of complex portfolio models, the companies often apply simpler allocation mechanisms, e.g., combinations of fixed investment budgets and materiality requirements. Analysing petroleum cases, we compare the allocations decisions generated by portfolio models and simpler mechanisms. We also discuss the implications of this capital allocation pattern for governments' design of tax systems and license conditions. (author)

  19. Adapting water allocation management to drought scenarios

    Directory of Open Access Journals (Sweden)

    P. Giacomelli

    2008-04-01

    Full Text Available Climate change dynamics have significant consequences on water resources on a watershed scale. With water becoming scarcer and susceptible to variation, the planning and reallocation decisions in watershed management need to be reviewed. This research focuses on an in-depth understanding of the current allocation balance of water resources among competitors, placed along the course of the Adda River. In particular, during the summer period, the demand for water dramatically increases. This is due to the increase in irrigation activities in the lower part of the basin and to the highest peaks of tourist inflow, in the Como Lake and Valtellina areas. Moreover, during these months, the hydroelectric reservoirs in the upper part of the Adda River basin (the Valtellina retain most of the volume of water coming from the snow and glacier melt. The existing allocation problem among these different competing users is exacerbated by the decreasing water supplies. The summer of 2003 testified the rise in a number of allocation problems and situations of water scarcity that brought about environmental and economical consequences. The RICLIC project is committed to the understanding of water dynamics on a regional scale, to quantify the volumes involved and offer local communities an instrument to improve a sustainable water management system, within uncertain climate change scenarios.

  20. Current Noise Spectrum of a Quantum Shuttle

    DEFF Research Database (Denmark)

    Flindt, Christian; Novotny, T.; Jauho, Antti-Pekka

    2005-01-01

    We present a method for calculating the full current noise spectrum S(omega) for the class of nano-electromechanical systems (NEMS) that can be described by a Markovian generalized master equation. As a specific example we apply the method to a quantum shuttle. The noise spectrum of the shuttle has...... peaks at integer multiples of the mechanical frequency, which is slightly renormalized. The renormalization explains a previously observed small deviation of the shuttle Current compared to the expected value given by the product of the natural mechanical frequency and the electron charge. For a certain...... parameter range the quantum shuttle exhibits a coexistence regime, where the charges are transported by two different mechanisms: Shuttling and sequential tunneling. In our previous studies we showed that characteristic features in the zero-frequency noise could be quantitatively understood as a slow...

  1. Efficient Power Allocation for Video over Superposition Coding

    KAUST Repository

    Lau, Chun Pong; Jamshaid, K.; Shihada, Basem

    2013-01-01

    are conducted to gain a better understanding of its efficiency, specifically, the impact of the received signal due to different power allocation ratios. Our experimental results show that to maintain high video quality, the power allocated to the base layer

  2. An approach involving dynamic group search optimization for allocating resources in OFDM-based cognitive radio system

    Directory of Open Access Journals (Sweden)

    Sameer Suresh Nanivadekar

    2018-03-01

    Full Text Available Allocation of channel resources in a cognitive radio system for achieving minimized transmission energy at an increased transmission rate is a challenging research. This paper proposes a resource allocation algorithm based on the meta-heuristic search principle. The proposed algorithm is an improved version of the Group Search Optimizer (GSO, which is a currently developed optimization algorithm that works through imitating the searching behaviour of the animals. The improvement is accomplished through introducing dynamics in the maximum pursuit angle of the GSO members. A cognitive radio system, relying on Orthogonal Frequency Division Multiplexing (OFDM for its operation, is simulated and the experimentations are carried out for sub-channel allocation. The proposed algorithm is experimentally compared with five renowned optimization algorithms, namely, conventional GSO, Particle Swarm Optimization, Genetic Algorithm, Firefly Algorithm and Artificial Bee Colony algorithm. The obtained results assert the competing performance of the proposed algorithm over the other algorithms. Keywords: Cognitive radio, OFDM, Resource, Allocation, Optimization, GSO

  3. Optimized Energy Efficiency and Spectral Efficiency Resource Allocation Strategies for Phantom Cellular Networks

    KAUST Repository

    Abdelhady, Amr, M.; Amin, Osama; Alouini, Mohamed-Slim

    2016-01-01

    Multi-teir hetrogeneous networks have become an essential constituent for next generation cellular networks. Meanwhile, energy efficiency (EE) has been considered a critical design criterion along with the traditional spectral efficiency (SE) metric. In this context, we study power and spectrum allocation for the recently proposed two-teir architecture known as Phantom cellular networks. The optimization framework includes both EE and SE, where we propose an algorithm that computes the SE and EE resource allocation for Phantom cellular networks. Then, we compare the performance of both design strategies versus the number of users, and the ration of Phantom cellresource blocks to the total number or resource blocks. We aim to investigate the effect of some system parameters to acheive improved SE or EE performance at a non-significant loss in EE or SE performance, respectively. It was found that the system parameters can be tuned so that the EE solution does not yield a significant loss in the SE performance.

  4. Optimized Energy Efficiency and Spectral Efficiency Resource Allocation Strategies for Phantom Cellular Networks

    KAUST Repository

    Abdelhady, Amr, M.

    2016-01-06

    Multi-teir hetrogeneous networks have become an essential constituent for next generation cellular networks. Meanwhile, energy efficiency (EE) has been considered a critical design criterion along with the traditional spectral efficiency (SE) metric. In this context, we study power and spectrum allocation for the recently proposed two-teir architecture known as Phantom cellular networks. The optimization framework includes both EE and SE, where we propose an algorithm that computes the SE and EE resource allocation for Phantom cellular networks. Then, we compare the performance of both design strategies versus the number of users, and the ration of Phantom cellresource blocks to the total number or resource blocks. We aim to investigate the effect of some system parameters to acheive improved SE or EE performance at a non-significant loss in EE or SE performance, respectively. It was found that the system parameters can be tuned so that the EE solution does not yield a significant loss in the SE performance.

  5. Generation and reception of spread-spectrum signals

    Science.gov (United States)

    Moser, R.

    1983-05-01

    The term 'spread-spectrum' implies a technique whereby digitized information is added to a pseudo-random number sequence and the resultant bit stream changes some parameter of the carrier frequency in discrete increments. The discrete modulation of the carrier frequency is usually realized either as a multiple level phase shift keyed or frequency shift keyed signal. The resultant PSK-modulated frequency spectrum is referred to as direct sequence spread-spectrum, whereas the FSK-modulated carrier frequency is referred to as a frequency hopped spread spectrum. These can be considered the major subsets of the more general term 'spread-spectrum'. In discussing signal reception, it is pointed out that active correlation methods are used for channel synchronization when the psuedo random sequences are long or when the processing gain is large, whereas the passive methods may be used for either short pseudo-random noise generation codes or to assist in attaining initial synchronization in long sequence spread-spectrum systems.

  6. High Frequency Components Recovery in Music Signals

    Directory of Open Access Journals (Sweden)

    V. Sebesta

    1999-04-01

    Full Text Available A new technique is presented which improves the subjective quality of band-limited music by recovery of high frequency components. Sequences of harmonics are found in the band-limited signal and these sequences are expanded to the high frequency band to estimate the lost part of spectrum. High frequency signal is generated to match this estimation and is added to the band-limited signal.

  7. Dynamic Asset Allocation and the Informational Efficiency of Markets.

    OpenAIRE

    Grossman, Sanford J

    1995-01-01

    Markets have an allocational role; even in the absence of news about payoffs, prices change to facilitate trade and allocate resources to their best use. Allocational price changes create noise in the signal extraction process, and markets where such trading is important are markets in which we may expect to find a failure of informational efficiency. An important source of allocational trading is the use of dynamic trading strategies caused by the incomplete equitization of risks. Incomplete...

  8. Constrained control allocation for systems with redundant control effectors

    OpenAIRE

    Bordignon, Kenneth A

    1996-01-01

    Control allocation is examined for linear time-invariant problems that have more controls than degrees of freedom. The controls are part of a physical system and are subject to limits on their maximum positions. A control allocation scheme commands control deflections in response to some desired output. The ability of a control allocation scheme to produce the desired output without violating the physical position constraints is used to compare allocation schemes. Methods are develop...

  9. Fundamental-driven and Tactical Asset Allocation: what really matters?

    OpenAIRE

    Hartpence, Maria; Boulier, Jean-François

    2004-01-01

    Asset allocation contribution to ex-post performance is of primary importance. Nobody denies its role, yet the subject of allocating assets remains controversial. To some contenders, the added value stems only from strategic asset allocation which aims at providing the long-term average exposure to the selected asset classes. On the other hand, proponents of active management have introduced several forms of tactical asset allocation. In this paper, we will go a step further by distinguishing...

  10. Matching today's allocation of LDC expenses with cost causation

    International Nuclear Information System (INIS)

    Yankel, A.J.

    1990-01-01

    This article discusses the costs of natural gas distribution and how to integrate these costs into the allocation of local distribution companies expenses for the purpose of establishing rate structures. The author's contention is that costs related to throughput are a larger share than historically used allocation factors suggest. Topics include the historical allocation factors, a case study and the conclusions drawn from it

  11. Resource Allocation for A Mobile Application Oriented Architecture

    NARCIS (Netherlands)

    Guo, Y.; Smit, Gerardus Johannes Maria; Lu, W.W.; Xie, X.

    2005-01-01

    A Montium is a coarse-grained reconfigurable architecture designed by the CADTES group of the University of Twente for mobile applications. This paper presents a resource allocation method to allocate variables to storage places and to schedule data movements for the Montium. The resource allocation

  12. Reward-allocation judgments in Romania : A factorial survey approach

    NARCIS (Netherlands)

    Buzea, C.; Meseşan-Schmitz, L.; van de Vijver, F.J.R.

    2013-01-01

    We investigated reward-allocation judgments when positive outcomes (monetary rewards) were distributed and the allocator was not a co-recipient, in a sample of 200 Romanian students. Within a full factorial survey design, seven factors, selected to affect the allocation decision, were orthogonally

  13. Risk allocation approach to reactor safety design and evaluation

    International Nuclear Information System (INIS)

    Gokcek, O.; Temme, M.I.; Derby, S.L.

    1978-01-01

    This paper describes a risk allocation technique used for determining nuclear power plant design reliability requirements. The concept of risk allocation-optimum choice of safety function reliabilities under a maximum risk constraint - is described. An example of risk allocation is presented to demonstrate the application of the methodology

  14. 30 CFR 206.459 - Allocation of washed coal.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Allocation of washed coal. 206.459 Section 206... MANAGEMENT PRODUCT VALUATION Indian Coal § 206.459 Allocation of washed coal. (a) When coal is subjected to washing, the washed coal must be allocated to the leases from which it was extracted. (b) When the net...

  15. 30 CFR 206.260 - Allocation of washed coal.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Allocation of washed coal. 206.260 Section 206... MANAGEMENT PRODUCT VALUATION Federal Coal § 206.260 Allocation of washed coal. (a) When coal is subjected to washing, the washed coal must be allocated to the leases from which it was extracted. (b) When the net...

  16. Energy-Efficient Power Allocation for Underlay Cognitive Radio Systems

    KAUST Repository

    Sboui, Lokman

    2015-09-01

    We present a power allocation framework for spectrum sharing Cognitive Radio (CR) systems based on maximizing the energy efficiency (EE). First, we show that the relation between the EE and the spectral efficiency (SE) is strictly increasing in contrast with the SE-EE trade-off discussed in the literature. We also solve a non-convex problem and explicitly derive the optimal power for the proposed average EE under either a peak or an average power constraint. We apply our results to the underlay CR systems where the power is limited by an additional interference constraint. When the instantaneous channel is not available, we provide a necessary and sufficient condition for the optimal power and present a simple sub-optimal power. In the numerical results, we show that the proposed EE corresponds to a higher SE at mid-range and high power regime compared to the classical EE. We also show that the sup-optimal solution is very close to the optimal solution. In addition, we deduce that the absence of instantaneous CSI affects the EE and the SE at high power regime compared to full CSI. In the CR context, we show that the interference threshold has a minimal effect on the EE compared to the SE.

  17. Resource allocation and MIMO for 4G and beyond

    CERN Document Server

    2014-01-01

    This book presents the underlying technological breakthroughs that allowed the current state of wireless technology development to evolve. The book focuses on the two lower layers of the ISO/OSI layered model, specifically the physical and data link layers including the media access control sub-layer. These two layers are of particular importance to wireless systems due to the spectrum shortage, the broadcast nature of interference, and time variability in the wireless channel. Topics covered in this book include: radio resource allocation (RRA) for emerging architectures such as Coordinated Multipoint (CoMP) and Device-to-Device communications (D2D); RRA for quality of service control; propagation and transceiver aspects of MIMO systems; and the design and selection of MIMO multiuser precoders. The proposed approaches for RRA and MIMO are applicable to mobile communication standards such as 3GPP’s LTE and LTE-Advanced, but also apply further to the continuously evolving wireless access technologies lan...

  18. Cognitive relaying and power allocation under channel state uncertainties

    KAUST Repository

    Pandarakkottilil, Ubaidulla

    2013-04-01

    In this paper, we present robust joint relay precoder designs and transceiver power allocations for a cognitive radio network under imperfect channel state information (CSI). The secondary (or cognitive) network consists of a pair of single-antenna transceiver nodes and a non-regenerative two-way relay with multiple antennas which aids the communication process between the transceiver pair. The secondary nodes share the spectrum with a licensed primary user (PU) while guaranteeing that the interference to the PU receiver is maintained below a specified threshold. We consider two robust designs: the first is based on the minimization of the total transmit power of the secondary relay node required to provide the minimum quality of service, measured in terms of mean-square error (MSE) of the transceiver nodes, and the second is based on the minimization of the sum-MSE of the transceiver nodes. The robust designs are based on worst-case optimization and take into account known parameters of the error in the CSI to render the performance immune to the presence of errors in the CSI. Though the original problem is non-convex, we show that the proposed designs can be reformulated as tractable convex optimization problems that can be solved efficiently. We illustrate the performance of the proposed designs through some selected numerical simulations. © 2013 IEEE.

  19. Energy-Efficient Power Allocation for Underlay Cognitive Radio Systems

    KAUST Repository

    Sboui, Lokman; Rezki, Zouheir; Alouini, Mohamed-Slim

    2015-01-01

    We present a power allocation framework for spectrum sharing Cognitive Radio (CR) systems based on maximizing the energy efficiency (EE). First, we show that the relation between the EE and the spectral efficiency (SE) is strictly increasing in contrast with the SE-EE trade-off discussed in the literature. We also solve a non-convex problem and explicitly derive the optimal power for the proposed average EE under either a peak or an average power constraint. We apply our results to the underlay CR systems where the power is limited by an additional interference constraint. When the instantaneous channel is not available, we provide a necessary and sufficient condition for the optimal power and present a simple sub-optimal power. In the numerical results, we show that the proposed EE corresponds to a higher SE at mid-range and high power regime compared to the classical EE. We also show that the sup-optimal solution is very close to the optimal solution. In addition, we deduce that the absence of instantaneous CSI affects the EE and the SE at high power regime compared to full CSI. In the CR context, we show that the interference threshold has a minimal effect on the EE compared to the SE.

  20. Autism Spectrum Disorder (ASD)

    Science.gov (United States)

    ... Español (Spanish) Recommend on Facebook Tweet Share Compartir Autism spectrum disorder (ASD) is a developmental disability that can cause ... work. Autism: What's New MMWR article: Prevalence of Autism Spectrum Disorder Data Community Report Press release: Autism Prevalence Slightly ...