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Sample records for dwdm radio-over-fibre link

  1. Digital coherent receiver employing photonic downconversion for phase modulated radio-over-fibre links

    DEFF Research Database (Denmark)

    Zibar, Darko; Caballero Jambrina, Antonio; Guerrero Gonzalez, Neil

    2009-01-01

    A digital coherent receiver employing photonic downconversion is presented and experimentally demonstrated for phase-modulated radio-over-fibre optical links. The receiver is capable of operating at frequencies exceeding the bandwidth of electrical analog-to-digital converter by using photonic...... downconversion to translate the high-frequency input RF signal to the operating frequency range of the analog-to-digital converter. First, using linear digital demodulation scheme we measure SFDR of the link at microwave frequency of 5 GHz. Thereafter, successful signal demodulation of 50 Mbit/s binary phase...... shift keying (BPSK) modulated data signal at 5 GHz RF carrier frequency is experimentally demonstrated by using an analog-to-digital converter with only 1 GHz bandwidth. We successfully demonstrate signal demodulation, using the proposed digital coherent receiver with photonic downconversion, after 40...

  2. Experimental 2.5 Gbit/s QPSK WDM coherent phase modulated radio-over-fibre link with digital demodulation by a K-means algorithm

    DEFF Research Database (Denmark)

    Guerrero Gonzalez, Neil; Caballero Jambrina, Antonio; Amaya Fernández, Ferney Orlando

    2009-01-01

    Highest reported bit rate of 2.5 Gbit/s for optically phase modulated radio-over-fibre link employing coherent detection is demonstrated. Demodulation of 3·2.5 Gbit/s QPSK modulated WDM channels, is achieved after 79km of transmission through deployed fiber.......Highest reported bit rate of 2.5 Gbit/s for optically phase modulated radio-over-fibre link employing coherent detection is demonstrated. Demodulation of 3·2.5 Gbit/s QPSK modulated WDM channels, is achieved after 79km of transmission through deployed fiber....

  3. Digital coherent receiver for phase modulated radio-over-fibre optical links

    DEFF Research Database (Denmark)

    Zibar, Darko; Yu, Xianbin; Peucheret, Christophe

    2009-01-01

    A novel digital signal processing-based coherent receiver for phase-modulated radio-over-fiber (RoF) optical links is presented and demonstrated experimentally. Error-free demodulation of 50-Mbaud binary phase-shift keying (BPSK) and quadrature phase-shift keying data signal modulated on a 5-GHz...... radio-frequency (RF) carrier is experimentally demonstrated using the proposed digital coherent receiver. Additionally, a wavelength-division-multiplexing (WDM) phase-modulated RoF optical link is experimentally demonstrated. A 3 x50 Mb/s WDM transmission of a BPSK modulated 5-GHz RF carrier is achieved...... over 25 km for the WDM channel spacing of 12.5 and 25 GHz, respectively....

  4. Linewidth tolerance of digital coherent receiver using Viterbi & Viterbi RF carrier recovery for radio-over-fibre links

    DEFF Research Database (Denmark)

    Guerrero Gonzalez, Neil; Zibar, Darko; Larsen, Knud J.

    2009-01-01

    for phase-modulated RoF optical links (2). The RF signal processing in (2) is performed using maximum likelihood RF carrier phase estimation (2). In this paper, we investigate the performance of the proposed digital coherent receiver in (2) using feedforward Viterbi & Viterbi RF carrier recovery algorithm...

  5. Coherent Detection of Wavelength Division Multiplexed Phase-Modulated Radio-over-Fibre Signals

    DEFF Research Database (Denmark)

    Zibar, Darko; Yu, Xianbin; Peucheret, Christophe

    2008-01-01

    A WDM phase-modulated Radio-over-Fibre link using digital coherent detection is experimentally demonstrated. 3 times 50 Mb/s WDM transmission of a BPSK modulated 5 GHz RF carrier is achieved over 25 km.......A WDM phase-modulated Radio-over-Fibre link using digital coherent detection is experimentally demonstrated. 3 times 50 Mb/s WDM transmission of a BPSK modulated 5 GHz RF carrier is achieved over 25 km....

  6. Experimental demonstration of a digital maximum likelihood based feedforward carrier recovery scheme for phase-modulated radio-over-fibre links

    DEFF Research Database (Denmark)

    Guerrero Gonzalez, Neil; Zibar, Darko; Yu, Xianbin

    2008-01-01

    Maximum likelihood based feedforward RF carrier synchronization scheme is proposed for a coherently detected phase-modulated radio-over-fiber link. Error-free demodulation of 100 Mbit/s QPSK modulated signal is experimentally demonstrated after 25 km of fiber transmission.......Maximum likelihood based feedforward RF carrier synchronization scheme is proposed for a coherently detected phase-modulated radio-over-fiber link. Error-free demodulation of 100 Mbit/s QPSK modulated signal is experimentally demonstrated after 25 km of fiber transmission....

  7. Digital coherent receiver for subcarrier multiplexed phase modulated radio-over-fibre signals

    DEFF Research Database (Denmark)

    Zibar, Darko; Larsen, Knud J.; Tafur Monroy, Idelfonso

    2009-01-01

    Digital coherent detection of multi-channel subcarrier multiplexed optically phase-modulated radio-over-fibre signals is experimentally demonstrated. Successful detection after transmission over a 40 km long fibre link of four or five 25 Mbaud BPSK/QPSK subcarrier channels in 5 GHz bandwidth...... is demonstrated using offline digital signal processing....

  8. Wavelet-Coding for Radio over Fibre

    DEFF Research Database (Denmark)

    Cavalcante, Lucas Costa Pereira

    As the fifth generation of mobile communication technology is developed and implemented, worldwide solutions propose the use of much greater spectrum allocations, including the millimetre-wave frequency band. Radioover-fiber (RoF) links allow straight forward integration of the mobile front...

  9. Digital coherent detection of multi-gigabit 40 GHz carrier frequency radio-over-fibre signals using photonic downconversion

    DEFF Research Database (Denmark)

    Caballero Jambrina, Antonio; Zibar, Darko; Tafur Monroy, Idelfonso

    2010-01-01

    Detection of high-speed radio signals is a challenge for next generation radio-over-fibre links, requiring high bandwidth and linearity in the receiver. By using photonic downconversion in a coherent receiver, detection of high bit-rate 16-QAM signals, up to 4 Gbit/s, at a 40 GHz carrier frequency...

  10. Development of DWDM Filter Manufacture

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    DWDM technology is developing rapidly. Thin film narrow bandpass filter plays an important role in this field. This article presents some achievements in developing the DWDM narrow bandpass filters and also describes the results achieved by us.

  11. Effect of the degree of phase-correlation of laser sources on the transmission and optical coherent detection in radio-over-fibre systems

    Science.gov (United States)

    Maldonado-Basilio, Ramón; Li, Ran; Abdul-Majid, Sawsan; Nikkhah, Hamdam; Leong, Kin-Wai; Hall, Trevor J.

    2013-01-01

    The deployment of high capacity Radio-over-Fiber (RoF) systems rely, among many aspects, on the capability to efficiently generate, transport, and detect millimeter-wave carriers modulated at high data rates. Photonic approaches based on the heterodyne beating of two free-running laser sources have been proposed as an alternative to generate multi-Gbps quadrature phase modulated signals imposed on millimeter wave carriers. Implementing photonic approaches in the down-link avoids the need for electronic generation of high frequency carriers and decreases the requirements at the base band electronics. In addition, implementing complex modulation formats overcomes some of the typical issues found in intensity modulation direct detection approaches such as non­ linearity, receiver sensitivity and dynamic range. In this work, the performance improvement of a coherent RoF system carrying 10 Gbps QPSK signals is numerically analyzed in terms of both the frequency linewidth and the degree of phase correlation between the lasers utilised at the down-link (for the optical heterodyne beating) and at the up-link (for the optical coherent detection). Relative to phase correlated lasers featuring linewidths of 5 MHz, the peak power of the 60 G Hz carrier generated at the down-link is reduced by 8 dB for un-correlated lasers. In addition, the error vector magnitude of the received signal at the up-link is improved from over 20% (for un-correlated lasers and linewidths of 5 MHz) to around 15% (for correlated lasers) at an optical received power of -30 dBm. The results obtained reinforce the idea of using coherent comb laser sources with phase correlated modes located at the Central Office. It also motivates the eventual deployment of techniques to control the degree of phase correlation between the lasers used as signal and local oscillator at the optical coherent receivers.

  12. Cognitive digital receiver for burst mode phase modulated radio over fiber links

    DEFF Research Database (Denmark)

    Guerrero Gonzalez, Neil; Zibar, Darko; Tafur Monroy, Idelfonso

    2010-01-01

    A novel cognitive receiver for modulation format recognition with reconfigurable carrier recovery scheme is proposed and experimentally demonstrated for phase modulated radio-over-fibre links. Demodulation of burst-mode mixed modulation formats (PSK and QAM) is demonstrated after 40km...

  13. IP over DWDM

    Science.gov (United States)

    Allen, Mark E.

    2003-04-01

    The industry has been full of many lively debates about exactly how the functions of layer 1 and 2 (physical layer and data-link layer) will be orchestrated to support the growing amount of IP traffic. In effect, this book must simultaneously address layers 1 through 3. Two main strengths of the book are in describing current state-of-the-art research in very-high-speed IP networks and in detailing the standards activities related to net-work management, software, and signaling.

  14. Time-Domain Optical Fourier Transformation for OTDM-DWDM and DWDM-OTDM Conversion

    DEFF Research Database (Denmark)

    Mulvad, Hans Christian Hansen; Palushani, Evarist; Galili, Michael

    2011-01-01

    Applications of time-domain optical Fourier transformation (OFT) in ultra-high-speed optical time-division multiplexed systems (OTDM) are reviewed, with emphasis on the recent demonstrations of OFT-based conversion between the OTDM and DWDM formats.......Applications of time-domain optical Fourier transformation (OFT) in ultra-high-speed optical time-division multiplexed systems (OTDM) are reviewed, with emphasis on the recent demonstrations of OFT-based conversion between the OTDM and DWDM formats....

  15. Solutions for 80 km DWDM systems

    DEFF Research Database (Denmark)

    Dochhan, Annika; Griesser, Helmut; Eiselt, Nicklas

    2016-01-01

    Currently discussed solutions for 80 km DWDM transmission targeting inter-data center connections at 100G and 400G line rates are reviewed. PDM-64QAM, PAM4, and discrete multi-tone transmission (DMT) are investigated, while the focus lies on directly detected solutions. For DMT, the vestigial...

  16. The Swiss Education and Research Network - SWITCH - Upgrades Optical Network to Transport 10 Gbps Using Sorrento Networks DWDM Platform

    CERN Multimedia

    2003-01-01

    "Sorrento Networks, a supplier of optical transport networking equipment for carriers and enterprises worldwide, today announced that SWITCH successfully completed 10 Gbps BER tests on the 220 km Zurich to Manno and 360 km Zurich to Geneva links in September and November 2003, using Sorrento's GigaMux DWDM system" (1/2 page).

  17. INVESTIGATION ON HYBRID WDM (DWDM+CWDM FREE SPACE OPTICAL COMMUNICATION SYSTEM

    Directory of Open Access Journals (Sweden)

    S. Robinson

    2015-12-01

    Full Text Available Free Space Optical (FSO communication is being realized as an effective solution for future accessing networks, offering light passed through air. The performance of FSO can be primarily degraded by various atmospheric attenuation namely, rain, fog, haze and snow. At present, hybridization of Dense Wavelength Division Multiplexing (DWDM with Coarse Wavelength Division Multiplexing (CWDM becomes necessary to scale the speed and high bandwidth of the services. In this paper, hybrid WDM system is proposed, designed and the network parameters such as Bit Error Rate (BER, Quality Factor and receiver sensitivity are analyzed with respect to link distance for various weather conditions. For investigation, 4 CWDM and 8 DWDM channels are considered whose corresponding channel spacing is 20nm and 0.8nm, respectively. From the simulation, it is investigated that the average link distance of proposed hybrid WDM-FSO system for DWDM and CWDM system at very clear condition are around 810km and 780km. The proposed hybrid WDM based FSO system is designed to handle the quality of transmission for 12 users, each at a data rate of 2.5Gbps.

  18. Manufacturing of lasers for DWDM systems

    Science.gov (United States)

    Campbell, Kevin T.; Robertson, Alexander J., Jr.; Wetzel, Steven J.

    1999-11-01

    The evolution of dense wavelength division multiplexing (DWDM) has allowed service provides a convenient and cost effective method to dramatically increase transmission capacity over existing and new fiber network systems. As the demand for bandwidth continues to increase, systems designers are responding by increasing both the number of channels and the data rates. This trend has placed considerable pressure on many of the underlying system components. One component that has been particularly challenged by this trend is the manufacture of semiconductor lasers. This paper reviews the technical and logistical challenges faced in the high volume manufacture of lasers to support DWDM systems. As the product portfolio continues to expand, precise execution and team work among multiple organizations is required to assure reliable shipping performance. Production scheduling and manufacturing operations must work closely to continuously re-prioritize the work in process in response to constantly changing channel demand and yield fluctuations. Wavelength prediction models must be developed that correlate in-process parameters to final device wavelength. These models are then applied to both in-process specification targeting and inventory management. Once the in-process specifications are properly targeted, the challenge moves to the fabrication processes, where processes are pushed to the limits of their control. Underpinning the entire effort must be an information management system in which parametric data is collected, wavelength prediction models are executed, and work in process inventory is controlled with respect to the final output volume and wavelength distribution.

  19. Flexible DWDM Grid Manipulation Using Four Wave Mixing-based Time Lenses

    DEFF Research Database (Denmark)

    Røge, Kasper Meldgaard; Guan, Pengyu; Mulvad, Hans Christian Hansen

    2014-01-01

    An experimental demonstration of dense wavelength-division multiplexing (DWDM) grid manipulation is carried out using two time lenses. A DWDM spectrum is compressed from a 100-GHz to a 28-GHz grid with error-free performance....

  20. Low-Cost Hybrid ROADM Architectures for Scalable C/DWDM Metro Networks

    DEFF Research Database (Denmark)

    Nooruzzaman, Md; Halima, Elbiaze

    2016-01-01

    be introduced to merge CWDM and DWDM traffic at the optical layer. This ensures two advantages: reduced initial investment and scalability for deploying DWDM channels in the future. This article presents various ROADM architectures, and explores the novel optical node architecture of hybrid C/DWDM networks......CWDM networks have proven to be a promising first-step metro and access network architecture, offering a significant cost advantage over DWDM due to the lower cost of lasers and the filters used in CWDM modules. If demand grows beyond the capacity covered by CWDM channels, DWDM network elements can......, consisting of CWDM, hybrid C/DWDM, and junction nodes connecting two rings. Evaluation has shown that the hybrid ROADM architecture is superior to other conventional ROADM architectures in terms of scalability and the initial cost of optical nodes and networks....

  1. Enterprise virtual private network (VPN) with dense wavelength division multiplexing (DWDM) design

    Science.gov (United States)

    Carranza, Aparicio

    An innovative computer simulation and modeling tool for metropolitan area optical data communication networks is presented. These models address the unique requirements of Virtual Private Networks for enterprise data centers, which may comprise a mixture of protocols including ESCON, FICON, Fibre Channel, Sysplex protocols (ETR, CLO, ISC); and other links interconnected over dark fiber using Dense Wavelength Division Multiplexing (DWDM). Our models have the capability of designing a network with minimal inputs; to compute optical link budgets; suggest alternative configurations; and also optimize the design based on user-defined performance metrics. The models make use of Time Division Multiplexing (TDM) wherever possible for lower data rate traffics. Simulation results for several configurations are presented and they have been validated by means of experiments conducted on the IBM enterprise network testbed in Poughkeepsie, N.Y.

  2. Planning and deployment of DWDM systems: a reality

    Science.gov (United States)

    Mishra, Data S.

    2001-10-01

    The new definition and implementation of new communication network architectures and elements in the present data-centric world are due to dramatic change in technology, explosive growth in bandwidth requirement and de-regulated, privatized and competitive telecommunication market. Network Convergence, Disruptive Technology and Convulsive Market are the basic forces who are pushing the future network towards Packet based Optical Core Network and varieties of Access Network along with integrated NMS. Well-known Moore's law governs the result of progress in silicon processing and accordingly the present capacity of network must be multiplied by 100 times in 10 years. To build a global network which is 100 times powerful than present one by scaling up today's technology can not be a practical solution due to requirement of 100 fold increase in cost, power and size. Today's two network (Low delay, fixed bandwidth, Poisson voice traffic based, circuit-switched PSTN/PLMN and variable delay, variable bandwidth, no-guaranteed QoS based packet switched internet) are converging towards two-layer network (IP and ATM in lower layer; DWDM in network layer). SDH Network which was well drafted before explosive data traffic and was best suitable for Interoperability, Survivability, Reliability and Manageability will be taken over by DWDM Network by 2005 due to 90% of data traffic. This paper describes the way to build the Communication Network (either by migration or by overlay) with an overview of the equipment and technologies required to design the DWDM Network. Service Providers are facing tough challenges for selection of emerging technologies and advances in network standard for bandwidth hungry, valued customers. The reduction of cost of services due to increased competition , explosive growth of internet and 10GbE Ethernet (which is being considered as an end-to-end network solution) have given surprise to many network architects and designers. To provide transparency to

  3. DWDM-TO-OTDM Conversion by Time-Domain Optical Fourier Transformation

    DEFF Research Database (Denmark)

    Mulvad, Hans Christian Hansen; Hu, Hao; Galili, Michael

    2011-01-01

    We propose DWDM-OTDM conversion by time-domain optical Fourier transformation. Error-free conversion of a 16×10 Gbit/s 50 GHz-spacing DWDM data signal to a 160 Gbit/s OTDM signal with a 2.1 dB average penalty is demonstrated.......We propose DWDM-OTDM conversion by time-domain optical Fourier transformation. Error-free conversion of a 16×10 Gbit/s 50 GHz-spacing DWDM data signal to a 160 Gbit/s OTDM signal with a 2.1 dB average penalty is demonstrated....

  4. Distributed Grooming in Multi-Domain IP/MPLS-DWDM Networks

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Qing [ORNL

    2009-12-01

    This paper studies distributed multi-domain, multilayer provisioning (grooming) in IP/MPLS-DWDM networks. Although many multi-domain studies have emerged over the years, these have primarily considered 'homogeneous' network layers. Meanwhile, most grooming studies have assumed idealized settings with 'global' link state across all layers. Hence there is a critical need to develop practical distributed grooming schemes for real-world networks consisting of multiple domains and technology layers. Along these lines, a detailed hierarchical framework is proposed to implement inter-layer routing, distributed grooming, and setup signaling. The performance of this solution is analyzed in detail using simulation studies and future work directions are also high-lighted.

  5. Combined Transmission of Baseband NRZ-DQPSK and Phase Modulated Radio-over-Fibre

    DEFF Research Database (Denmark)

    Jensen, Jesper Bevensee; Yu, Xianbin; Tafur Monroy, Idelfonso

    2008-01-01

    21.4 Gbit/s baseband DQPSK and 1.25 Gbit/s phase modulated RoF was transmitted over 80 km SSMF using polarization multiplexing.......21.4 Gbit/s baseband DQPSK and 1.25 Gbit/s phase modulated RoF was transmitted over 80 km SSMF using polarization multiplexing....

  6. Análisis de la Transmisión de Tramas STM-N sobre un Enlace de Fibra Óptica DWDM

    Directory of Open Access Journals (Sweden)

    Julio C. Agudelo-Ramirez

    2010-12-01

    Full Text Available In this work, we present an analysis of physical layer performance of a DWDM-link of 66 km of single-mode optical fiber on which is implemented a SDH system to send STM-1 at 155 Mbps. We show the computational simulation in Optisystem 7.0 (Evaluation Version to analyze the DWDM system characteristic at 2.5 Gbps equivalent to a STM-16 frame. The results of the eye diagram and BER show that is possible to distinguish between bits when the detector thermal-noise is less than 1x10-19 W/Hz. We analyze experimental measurements of jitter and its corresponding comparison with the value normalized by the ITU-T for a STM-1 frame. The use of more wavelengths is proposed to maximize the transmission capacity of fiber optics or installation of interfaces with high capacity for increasing the available bandwidth.

  7. Symmetric reconfigurable capacity assignment in a bidirectional DWDM access network.

    Science.gov (United States)

    Ortega, Beatriz; Mora, José; Puerto, Gustavo; Capmany, José

    2007-12-10

    This paper presents a novel architecture for DWDM bidirectional access networks providing symmetric dynamic capacity allocation for both downlink and uplink signals. A foldback arrayed waveguide grating incorporating an optical switch enables the experimental demonstration of flexible assignment of multiservice capacity. Different analog and digital services, such as CATV, 10 GHz-tone, 155Mb/s PRBS and UMTS signals have been transmitted in order to successfully test the system performance under different scenarios of total capacity distribution from the Central Station to different Base Stations with two reconfigurable extra channels for each down and upstream direction.

  8. Analysis the Performance of Coded WSK-DWDM Transmission System

    Directory of Open Access Journals (Sweden)

    Bobby Barua

    2012-12-01

    Full Text Available Dense Wavelength Division Multiplexing (DWDM is the system with more than eight active wavelengths per fiber. Again high data rates as well as long spans between amplifiers in a chain require high optical power per channel to satisfy the signal to noise ratio (SNR requirements. So the DWDM systems with long repeater-less spans, the simultaneous requirements of high launched power and low dispersion fibers lead to the generation of new waves by four-wave mixing (FWM, which degrades the performance of a multi-channel transmission system. Several methods have been proposed to mitigate the effect of FWM crosstalk. All these works are performed considering only binary WSK scheme. Although M-ary WSK (M>2 schemes have higher spectral efficiency than binary WSK system. Again, the BER performances for M-ary WDM system are not satisfactory with the effect of FWM. Therefore, in this paper we include the effect of FWM on the performance of an M-ary WDM system and try to mitigate the effect by employing the energy efficient convolution code in a normal dispersive fiber as well as in a dispersion shifted fiber (DSF.

  9. DWDM Fiber-Wireless Access System with Centralized Optical Frequency Comb-based RF Carrier Generation

    DEFF Research Database (Denmark)

    Pang, Xiaodan; Beltrán, Marta; Sánchez, José;

    2013-01-01

    We propose and experimentally demonstrate an optical wireless DWDM system at 60 GHz with optical incoherent heterodyne up-conversion using an optical frequency comb. Multiple users with wireline and wireless services are simultaneously supported.......We propose and experimentally demonstrate an optical wireless DWDM system at 60 GHz with optical incoherent heterodyne up-conversion using an optical frequency comb. Multiple users with wireline and wireless services are simultaneously supported....

  10. Cross-phase modulation-induced penalties in multichannel DWDM optical transport networks

    Institute of Scientific and Technical Information of China (English)

    Xu Zhu(朱栩); Qingji Zeng(曾庆济)

    2003-01-01

    In dense wavelength division multiplexing (DWDM) optical transmission systems, cross-phase modulation(XPM) due to Kerr effect causes phase shift on each channel, which will ultimately be transformed toamplitude noise that leads to power penalties. In this letter, the XPM-induced penalty in multi-channelDWDM systems is investigated theoretically and an applied algorithm that can be practically used inengineering design is proposed.

  11. Optimal design of an IP/MPLS over DWDM network

    Directory of Open Access Journals (Sweden)

    Eduardo Canale

    2014-04-01

    Full Text Available Different approaches for deploying resilient optical networks of low cost constitute a traditional group of NP-Hard problems that have been widely studied. Most of them are based on the construction of low cost networks that fulfill connectivity constraints. However, recent trends to virtualize optical networks over the legacy fiber infrastructure, modified the nature of network design problems and turned inappropriate many of these models and algorithms. In this paper we study a design problem arising from the deployment of an IP/MPLS network over an existing DWDM infrastructure. Besides cost and resiliency, this problem integrates traffic and capacity constraints. We present: an integer programming formulation for the problem, theoretical results, and describe how several metaheuristics were applied in order to find good quality solutions, for a real application case of a telecommunications company.

  12. Conversion of a DWDM signal to a single Nyquist channel based on a complete optical Fourier transformation

    DEFF Research Database (Denmark)

    Guan, Pengyu; Røge, Kasper Meldgaard; Mulvad, Hans Christian Hansen;

    2014-01-01

    We propose a DWDM-to-Nyquist channel conversion scheme based on complete Optical Fourier Transformation and optical Nyquist filtering. We demonstrate conversion from 50-GHz-grid 16×10 Gbit/s DPSK DWDM to a 160-Gbit/s Nyquist channel (0.9 symbol/s/Hz spectral efficiency) with 1.4 dB power penalty....

  13. Digital services using quadrature amplitude modulation (QAM) over CATV analog DWDM system

    Science.gov (United States)

    Yeh, JengRong; Selker, Mark D.; Trail, J.; Piehler, David; Levi, Israel

    2000-04-01

    Dense Wavelength Division Multiplexing (DWDM) has recently gained great popularity as it provides a cost effective way to increase the transmission capacity of the existing fiber cable plant. For a long time, Dense WDM was exclusively used for baseband digital applications, predominantly in terrestrial long haul networks and in some cases in metropolitan and enterprise networks. Recently, the performance of DWDM components and frequency-stabilized lasers has substantially improved while the costs have down significantly. This makes a variety of new optical network architectures economically viable. The first commercial 8- wavelength DWDM system designed for Hybrid Fiber Coax networks was reported in 1998. This type of DWDM system utilizes Sub-Carrier Multiplexing (SCM) of Quadrature Amplitude Modulated (QAM) signals to transport IP data digital video broadcast and Video on Demand on ITU grid lightwave carriers. The ability of DWDM to provide scalable transmission capacity in the optical layer with SCM granularity is now considered by many to be the most promising technology for future transport and distribution of broadband multimedia services.

  14. DESIGN OF DPSK MODULATOR AND DIRECT DETECTION RECEIVER FOR DWDM BASED OPTICAL COMMUNICATION SYSTEM

    Directory of Open Access Journals (Sweden)

    Gurjit Kaur

    2016-06-01

    Full Text Available In this paper a 16-bit differential phase shift keying (DPSK modulator is designed for 32 dense wavelength division multiplexing (DWDM channels. The DWDM channels are designed with 0.8nm separation in wavelength and operated at 4dBm input power. In the DWDM system, these 32 multiplexed signals propagate through a fiber length of 100 km followed by an erbium-doped fiber amplifier (EDFA inline. The channel is equipped with pre-amplifier and a dispersion compensating fiber for better performance. Also, a threshold detector is designed for both in-phase and quadrature components to detect the input amplitude and provide a quantized output amplitude level. The result shows that, a 16-bit DPSK optical signal is demodulated successfully using direct detection receiver.

  15. Reconfigurable Radio Access Unit for DWDM to W-Band Wireless Conversion

    DEFF Research Database (Denmark)

    Chorchos, Łukasz; Rommel, Simon; Turkiewicz, Jarosław P.

    2017-01-01

    via software. The RAU allows selection of a DWDM channel and tuning of the radio carrier frequency. Real-time transmission results at 2.5 Gbit/s and performance measurements with offline data processing at 4 and 5 Gbit/s are presented. Error free real-time transmission was achieved after 15km...

  16. Channel Capacity of DWDM Networks with Cross-phase Modulation Effect

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In dense wavelength division multiplexing(DWDM) optical transmission systems, cross phase modulation(XPM) due to Kerr effect causes phase shift and intensity modulation in each channel, which will lead the channel capacity to be a random variable. An expression of the channel capacity dealing with XPM effect is presented, and the correctness and accuracy of this method are demonstrated by numerical simulation.

  17. Optimal Dispersion of NZ-DSF in 40 Gbit/s DWDM Transmission

    Institute of Scientific and Technical Information of China (English)

    M. Tanaka; J. Kobayashi; T. Okuno; E. Sasaoka; Y. Araya; E. Tsumura; M. Shigematsu

    2003-01-01

    Numerical and experimental verification of optimal dispersion of NZ-DSF in 40Gb/s-based DWDM transmission are performed using 240km simple transmission line. The results show that dispersion of +8ps/nm/km is effective in 40Gb/s as well as 10Gb/s.

  18. A 400 Gbps/100 m free-space optical link

    Science.gov (United States)

    Lin, Chun-Yu; Lu, Hai-Han; Ho, Chun-Ming; Cheng, Ming-Te; Huang, Sheng-Jhe; Wang, Yun-Chieh; Chi, Jing-Kai

    2017-02-01

    A 400 Gbps/100 m free-space optical (FSO) link with dense-wavelength-division-multiplexing (DWDM)/space-division-multiplexing (SDM) techniques and a doublet lens scheme is proposed. To the best of our knowledge, this is the first time that a link adopting DWDM and SDM techniques and a doublet lens scheme has demonstrated a 400 Gbps/100 m FSO link. The experimental results show that the free-space transmission rate is significantly enhanced by the DWDM and SDM techniques, and the free-space transmission distance is greatly increased by the doublet lens scheme. A 16-channel FSO link with a total transmission rate of 400 Gbps (25 Gbps/λ  ×  16 λ  =  400 Gbps) over a 100 m free-space link is successfully demonstrated. Such a 400 Gbps/100 m DWDM/SDM FSO link provides the advantages of optical wireless communications for high transmission rates and long transmission distances, which is very useful for high-speed and long-haul light-based WiFi (LiFi) applications.

  19. QoS multicast routing scheme using QGA in IP/DWDM networks

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This article studies multi-constraints least-cost multicast routing problem in internet protocol over dense wavelength division multiplexing (IP/DWDM) networks. To address this problem, an individual-difference-based quantum genetic algorithm (IDQGA) is proposed. This algorithm considers individual differences among chromosomes by introducing an adaptive rotation angle step determination scheme and a grouping-based quantum mutation operation. Simulations are conducted over network topologies. The results indicate that compared with other heuristic algorithms, IDQGA has better optimal performance on solving quality of service (QoS) multicast routing problem in IP/DWDM networks and is characterized by strong robustness, high success ratio and excellent capability on global searching.

  20. Design of Super Narrowband DWDM Filters Based on the Effect of Spectral Splitting

    Energy Technology Data Exchange (ETDEWEB)

    Huang, C Q; Chen, M [College of Physics and Electronics, Hunan Institute of Science and Technology, Yueyang 414006 (China); Liu, J; Wan, Z M; Luo, Z M [College of Information and Communication Engineering, Hunan Institute of Science and Technology, Yueyang 414006 (China); Tian, P, E-mail: namecqh@yahoo.com.cn [College of Optoelectronic Science and Engineering, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074 (China)

    2011-02-01

    A novel approach is proposed to design super narrowband DWDM Filters consisting of multiple quantum wells (MQWs) by employing photonic crystals. Numerical investigations prove that the closed-cavity MQWs are more suitable for DWDM systems compared with the open-cavity MQWs. It is shown that different confined states could emerge from photonic band gap, which can be used as high-frequency carriers one-to-one. It is also found that these proposed MQWs could split the single spectral lines into multiples based on the effect of spectral splitting, and the number of the splitting is just equal to the number of the wells. In this way, the density of carriers can be increased multiplicatively in the same wave band, and thus the spectral efficiency can be improved multiplicatively. These results provide the prospects of channel density maximization and effective bandwidth optimization for optical communication.

  1. Centralized optical-frequency-comb-based RF carrier generator for DWDM fiber-wireless access systems

    DEFF Research Database (Denmark)

    Pang, Xiaodan; Beltran, Marta; Sanchez, Jose;

    2014-01-01

    In this paper, we report on a gigabit capacity fiber-wireless system that enables smooth integration between high-speed wireless networks and dense wavelength-division-multiplexing (DWDM) access networks. By employing a centralized optical frequency comb, both the wireline and the wireless services....... For demonstration, we transmit a 2.5 Gbit/s signal through the proposed system and successfully achieve a bit-error-rate (BER) performance well below the 7% overhead forward error correction limit of the BER of 2 × 10¿3 for both the wireline and the wireless signals in the 60 GHz band after 25 km single-mode fiber...... for each DWDM user can be simultaneously supported. Besides, each baseband channel can be transparently upconverted tomultiple radio-frequency (RF) bands for different wireless standards, which can be flexibly filtered at the end user to select the on-demand RF band, depending on the wireless applications...

  2. Design and realization of an all-fiber broadband tunable gain equalization filter for DWDM signals.

    Science.gov (United States)

    Varshney, R K; Nagaraju, B; Singh, A; Pal, B P; Kar, A K

    2007-10-17

    Design and fabrication of a tunable gain equalization filter for dense wavelength division multiplexed (DWDM) signals through erbium doped fiber amplifiers (EDFA) is reported. It is based on a side-polished fiber (SPF) half-coupler block loaded with a displaceable tapered multimode overlay waveguide (MMOW). A simple and accurate normal mode analysis is employed to design this filtering device for its subsequent realization. Equalization of a typical EDFA gain spectrum in the C-band within +/-0.35 dB or even less in the presence of various ITU standard C-band DWDM signal channels is demonstrated under varied operating conditions like add/drop of signals. Tunability of the filter notch is achieved through displacement of the SPF relative to the MMOW.

  3. Analysis of Video Signal Transmission Through DWDM Network Based on a Quality Check Algorithm

    Directory of Open Access Journals (Sweden)

    A. Markovic

    2013-04-01

    Full Text Available This paper provides an analysis of the multiplexed video signal transmission through the Dense Wavelength Division Multiplexing (DWDM network based on a quality check algorithm, which determines where the interruption of the transmission quality starts. On the basis of this algorithm, simulations of transmission for specific values of fiber parameters ​​ are executed. The analysis of the results shows how the BER and Q-factor change depends on the length of the fiber, i.e. on the number of amplifiers, and what kind of an effect the number of multiplexed channels and the flow rate per channel have on a transmited signals. Analysis of DWDM systems is performed in the software package OptiSystem 7.0, which is designed for systems with flow rates of 2.5 Gb/s and 10 Gb/s per channel.

  4. Investigation of DWDM System Based on Cascaded Four-Wave Mixing

    OpenAIRE

    Spolītis, S; Lyashuk, I

    2011-01-01

    Four-wave mixing (FWM) in optical fibers refers to a nonlinear interaction among four different waves, in which the energy and wave-vector must be conserved. This requirement is often referred to as phase matching and depends strongly on the chromatic dispersion. FWM has received the attention in fiber optic parametric amplifiers due to the possibility to work in more optical regions than erbium doped fiber amplifier (EDFA) widely used in DWDM networks. This feature of FOPAs makes it poss...

  5. A novel DWDM method to design a 100-kW Laser

    Science.gov (United States)

    Basu, Santanu

    2010-02-01

    In this paper, I will present the design analysis of a novel concept that may be used to generate a diffraction-limited beam from an aperture so that as much as 450 kW of laser power can be efficiently deposited on a diffraction-limited spot at a range. The laser beam will be comprised of many closely spaced wavelength channels as in a DWDM. The technique relies on the ability of an angular dispersion amplifier to multiplex a large number of high power narrow frequency lasers, wavelengths of which may be as close as 0.4 nm.

  6. DWDM laser arrays fabricated using thermal nanoimprint lithography on Indium Phosphide substrates

    DEFF Research Database (Denmark)

    Smistrup, K.; Nørregaard, J.; Mironov, A.;

    Dense Wavelength Division Multiplexing (DWDM) lasers play a major role in today’s long-haul broadband communication. Typical distributed feedback (DFB) laser cavities consist of long half-pitch gratings in InGaAsP on InP substrates with pitches around 240 nm. Lasers are made reliably single mode ....... The fabricated lasers were cleaved and measured. Laser arrays exhibited >40mW optical power in all 12 channels. Figure 3 shows the overlaid spectra of a 12-channel array laser chip with uniform (~3nm) wavelength spacing and good sidemode suppression....

  7. Dynamic energy management employing renewable energy sources in IP over DWDM networks

    DEFF Research Database (Denmark)

    Chen, Xin; Phillips, Chris; Wang, Jiayuan

    2013-01-01

    The continued growth of energy consumption has been one of the main constraints for the development of the Internet. The increasing emissions of greenhouse gases associated with electricity generation also raise public concern for the environment. In this paper, we propose a dynamic energy...... management framework employing renewable energy sources in IP over DWDM core networks. The main concept is to combine infrastructure sleeping and virtual router migration to improve the network energy efficiency. By using the energy source information provided by the smart grid, the nodes that are powered...

  8. Analysis of Pulse Tolerance to Pump Depletion Induced Noise in DWDM Systems Using Distributed Fiber Raman Amplifiers

    Institute of Scientific and Technical Information of China (English)

    YAN Minhui; CHEN Jianping; LI Jianlang; JINAG Wenning; CHEN Junfeng; LI Xin

    2002-01-01

    In distributed optical fiber Raman amplifiers,instantaneous pump power depletion is related to patterns of input DWDM signals and results in extra optical noise and crosstalk.This noise has different effects on non-return-to-zero (NRZ) and return-to-zero (RZ) pulse forms.These phenomena are compared with present simulation results.

  9. 80-Channel Multiplexer-Demultiplexer Module for DWDM Communications using Hybrid AWG -- Interleaver Technology

    Science.gov (United States)

    Rablau, Corneliu; Bredthauer, Lance

    2007-10-01

    Aside from the more traditional data, voice and e-mail communications, new bandwidth intensive applications in the larger consumer markets, such as music, digital pictures and movies, have led to an explosive increase in the demand for transmission capacity for optical communications networks. This has resulted in a widespread deployment of Dense Wavelength Division Multiplexing (DWDM) as a means of increasing the communications capacity by multiplexing and transmitting signals of different wavelengths (establishing multiple communication channels) through a single strand of fiber. We report on the design, assembly and characterization of a 50-GHz, 80-channel Mux-Demux module for DWDM systems. The module has been assembled from two commercially available 100 GHz, 40-channel Array Waveguide Grating (AWG) modules and a 50-GHz to 100-GHz interleaver. Relevant performance parameters such as insertion loss, channel uniformity, next-channel isolation (crosstalk) and integrated cross-talk are presented and discussed in contrast with the performance of other competing technologies such as Thin-Film-Filter-based Mux-Demux devices.

  10. Research on fault location technology based on BP neural network in DWDM optical network

    Institute of Scientific and Technical Information of China (English)

    LIAO Xiao-min; ZHANG Yin-fa; YANG Shi-ping; LIN Chu-shan

    2008-01-01

    BP neural network is introduced to the fault location field of DWDM optical network in this paper. The alarm characteris-tics of the optical network equipments are discussed, and alarm vector and fault vector diagrams are generated by analyzingsome typical instances. A 17×14×18 BP neural network structure is constructed and trained by using MATLAB. Bycomparing the training performances, the best training algorithm of fault location among the three training algorithms ischosen. Numerical simulation results indicate that the sum squared error (SSE) of fault location is less than 0.01, and theprocessing time is less than 100 ms. This method not only well deals with the missing alarms or false alarms, but alsoimproves the fault location accuracy and real-time ability.

  11. Narrowband DWDM filters based on Fibonacci-class quasi-periodic structures.

    Science.gov (United States)

    Golmohammadi, S; Moravvej-Farshi, M K; Rostami, A; Zarifkar, A

    2007-08-20

    In this paper, we propose a narrowband DWDM filter structure, whose reflection band characteristics, meets the ITU-T standard. The proposed filter structure is based on Fibonacci quasi-periodic structures composed of multilayers with large index differences. Studying the effects of the optical and geometrical parameters of Fibonacci quasi-periodic structures on its filtering properties, we have realized that to achieve the ITU-T standard, we need to cascade two successive structures both with the same generation numbers j=4 and orders n=25 and apodized refractive indices. The apodization process helps to minimize the stop band sidelobes. We have also demonstrated that beside Fibonacci's order, n, the layers dimensions, and their refractive index ratios are the main design parameters.

  12. CSO/CTB/BER performances improvement in a bi-directional hybrid DWDM system

    Institute of Scientific and Technical Information of China (English)

    Hai-Han Lu(吕海涵); Hsu-Hung Huang(黄旭弘); Ming-Chuan Wang(王明傅); Heng-Sheng Su(蘇(恒)生)

    2003-01-01

    Experimental verifications of the feasibility of using chirped fiber grating (CFG) as the dispersion compen-sation device in a bi-directional hybrid dense-wavelength-division-multiplexing (DWDM) system to reducethe dispersion and cross-phase modulation (XPM) induced crosstalk were proposed and demonstrated.Not only channel capacity was increased, but also good performances of carrier-to-noise ratio (CNR) ≥ 50dB, composite second order (CSO) ≥72 dB, composite triple beat (CTB) ≥69 dB and low bit error rate(BER) < 10-9 were achieved in our proposed system over a 50-km single-mode fiber (SMF) transport.

  13. 40  Gb/s DWDM Structure with Optical Phase Configuration for Long-Haul Transmission System

    Science.gov (United States)

    Lin, Hsiu-Sheng; Lai, Po-Chou

    2017-03-01

    We propose the experimental transport of 48 channels with 40 Gbit/s dense wavelength-division multiplexing (DWDM) system that uses single-mode fiber (SMF) in combination with dispersion compensation fiber (DCF) which is a dispersion compensation device, in C and L band wavelength range to solve the dispersion program. The DWDM system scheme employing single Mach-Zehnder modulation (MZM) return-to-zero differential phase-shift keying (RZ-DPSK) modulation format with hybrid Raman/EDFA (Erbium-doped fiber amplifier) configuration to improve transmission signal, and employing an optical phase conjugation (OPC) configuration in the middle line. That can compensate for dispersion impairment and improve nonlinear effects to investigate transmission distance performances.

  14. Performance Analysis of DWDM System for Different Modulation Schemes Using Variations in Channel Spacing

    Science.gov (United States)

    Sharma, Divya; Prajapati, Y. K.

    2016-12-01

    This paper reflects the analytical study of dense wavelength division multiplexed optical network with different number of channels at various channel spacing in order to achieve higher data rates by means of few advanced modulation schemes. Bit error rate and quality factor are being analyzed with the variation in number of channels, channel spacing and transmission length of fiber. Advanced modulation schemes being compared here are carrier suppressed return to zero (CSRZ), duobinary return to zero (DRZ), modified duobinary return to zero (MDRZ), 33 % differential phase shift keying (33 % DPSK), 66 % DPSK and differential quaternary phase shift keying (DQPSK). It is keenly observed that CSRZ scheme with 100 GHz channel spacing serves best performance in terms of max. Q factor, min. BER and maximum transmission coverage upto 4,000 km for 16 and 32 channels DWDM system since CSRZ is high tolerant to nonlinear effects. On the other hand, MDRZ scheme with 75 GHz channel spacing exhibits transmission coverage upto 4,000 km and 4,500 km for 16 and 32 channels respectively, but with degraded signal due to effect of inter symbol interference (ISI).

  15. New Compensation Technique for Fiber Impairments in Ultra High Capacity Super channel Based on (QDPASK Dense wavelength division multiplex (DWDM systems

    Directory of Open Access Journals (Sweden)

    Ibrahim A.Murdas

    2017-07-01

    Full Text Available In this paper we want to increase the data rate and to get larger transmission distance, therefore we use the Advanced modulation technique QDPASK in DWDM system with low channels space. In case of long transmission distance and multi channels system both giving rise to inter channel crosstalk induced by fiber nonlinearities as a result the use of advanced modulation technique becomes difficult. In this paper Quaternary differential phase amplitude shift keying (QDPASK is designed for 32 dense wavelength division multiplexing (DWDM channels, therefore we proposed a new cascade compensation system consist of optical and digital back propagation techniques (ODBP for compensate the linear and nonlinear effects . A performance of the system was reported using QDPASK DWDM fiber-optic system for various system parameters. The research is tested in VPI maker environment.

  16. Channel-reuse bidirectional transmission at 10 Gb/s/λ in long-reach DWDM-PON employing self wavelength managed tunable laser

    Science.gov (United States)

    Zhang, Zhiguo; Wang, Jiahe; Jiang, Xu; Chen, Xue; Wang, Liqian

    2015-05-01

    We experimentally demonstrate a channel-reuse, bidirectional, 10 Gb/s/λ, long-reach dense wavelength-division-multiplexing passive optical network (DWDM-PON) and an optical beat noise-based automatic wavelength control method for a tunable laser used in a colorless optical network unit (ONU). A 42 km reach, channel-reuse, full-duplex, 10 Gb/s transmission on a 50 GHz DWDM grid is achieved. Transmission performance is also measured with different optical-signal-to-Rayleigh-backscattering-noise ratios (OSRBNRs) and different central wavelength shifts (WSs) between upstream signal and downstream signal in the channel-reuse system.

  17. 740 Gbit/s (37 x 20 Gbit/s) DWDM Transmission Experiment Using Er~(3+)-Doped Tellurite Fiber Amplifiers and Distributed Raman Amplification

    Institute of Scientific and Technical Information of China (English)

    Hiroyuki; Toda; Maoki; Suzuki; Ryo; Takami; Tetsuya; Miyazaki; Takeshi; Makino; Fumito; Kubota

    2003-01-01

    We demonstrate 740 Gbit/s (37 x 20 Gbit/s) DWDM recirculating transmission experiment with 59 nm continuous bandwidth over 300 km by employing Er3+-doped tellurite fiber amplifiers. The use of Raman amplification is effective to increase the transmission bandwidth.

  18. Effect of soil temperature on one-way optical frequency transfer through dense-wavelength-division-multiplexing fibre links

    CERN Document Server

    Pinkert, T J; Jansen, G S M; Dijck, E A; Groeneveld, B G H M; Smets, R; Bosveld, F C; Ubachs, W; Jungmann, K; Eikema, K S E; Koelemeij, J C J

    2014-01-01

    Results of optical frequency transfer over a carrier-grade dense-wavelength-division-multiplexing (DWDM) optical fibre network are presented. The relation between soil temperature changes on a buried optical fibre and frequency changes of an optical carrier through the fibre is modelled. Soil temperatures, measured at various depths by the Royal Netherlands Meteorology Institute (KNMI) are compared with observed frequency variations through this model. A comparison of a nine-day record of optical frequency measurements through the 2 x 298 km fibre link with soil temperature data shows qualitative agreement. A soil temperature model is used to predict the link stability over longer periods (days-months-years). We show that one-way optical frequency dissemination is sufficiently stable to distribute and compare e.g. rubidium frequency standards over standard DWDM optical fibre networks.

  19. Effect of soil temperature on optical frequency transfer through unidirectional dense-wavelength-division-multiplexing fiber-optic links.

    Science.gov (United States)

    Pinkert, T J; Böll, O; Willmann, L; Jansen, G S M; Dijck, E A; Groeneveld, B G H M; Smets, R; Bosveld, F C; Ubachs, W; Jungmann, K; Eikema, K S E; Koelemeij, J C J

    2015-02-01

    Results of optical frequency transfer over a carrier-grade dense-wavelength-division-multiplexing (DWDM) optical fiber network are presented. The relation between soil temperature changes on a buried optical fiber and frequency changes of an optical carrier through the fiber is modeled. Soil temperatures, measured at various depths by the Royal Netherlands Meteorology Institute (KNMI) are compared with observed frequency variations through this model. A comparison of a nine-day record of optical frequency measurements through the 2×298  km fiber link with soil temperature data shows qualitative agreement. A soil temperature model is used to predict the link stability over longer periods (days-months-years). We show that optical frequency dissemination is sufficiently stable to distribute and compare, e.g., rubidium frequency standards over standard DWDM optical fiber networks using unidirectional fibers.

  20. Quantifying the Q-Factor and Minimizing BER in 32-Channel DWDM System Design Using EDFA and RAMAN Amplifiers

    Directory of Open Access Journals (Sweden)

    Tufail Ahmed Waseer

    2014-01-01

    Full Text Available In this work we have designed, modeled and simulated a 32-channel DWDM (Dense Wavelength Division Multiplexing system using OptiSystem photonic simulator. The system is tested for external transmitter with NRZ (Non-Return Zero encoder using Mech-Zehnder modulator, which accepts input from CW (Continuous Wave laser array and low pass Bessel filter that supports PIN photodiode at receiver end. System performance for optical channels has been compared by varying channel length of EDFA (Erbium Doped Fiber Amplifier and Raman amplifiers to identify its impact in the sense of eye diagram, QF (Quality Factor and minimum BER (Bit Error Rate. Experimental setup was done by varying channel lengths of 60, 100, 120, 150 and 170Kms. It was found that EDFA has better performance in the sub-low ranges of 60Kms, whereas Raman offers better performance at wider channel lengths i.e. more than 100Kms. The proposed work can be extend for the avoidance of amplifier utilization at wider ranged.

  1. New Method For Modeling and Design Optical SDM Transmission System Using Long Haul FMF with PDM/DWDM Techniques Enabling QPSK Modulation Format

    Directory of Open Access Journals (Sweden)

    Ibrahim Abdullah

    2017-07-01

    Full Text Available This paper presents the modeling and design of ultra high capacity Space Division Multiplexing (SDM transmission system. Polarization Division Multiplexing (PDM and Dense Wavelength Division Multiplexing (DWDM techniques are also proposed in this system to increase total system data rate. For the ultra-high capacity need of SDM, Few Mode Fiber (FMF was proposed as SDM best technology for obtaining ultra-high bit rates with long haul transmission. The description and design of 8-DWDM channels over 7 modes SDM/PDM system was explored as future of ultra-high capacity optical network. A long-haul transmission of 1080 Km recorded for 8-WDM channels-7modes-SDM/PDM system by using QPSK modulation format. The total bit rate achieved by our designed system is 4.48 Tb/s at 40Gb/s. Channel estimation techniques were proposed to enable the transmitter pre-shaping design for the linear effects mitigation by using different DSP algorithms. The presence of linear and nonlinear losses limits the acceptable range of input power that produce the required BER for our proposed system from -4dBm to 4dBm.

  2. WiMAX radio-on-fibre in 118-km long-reach PON with deployed fibre

    DEFF Research Database (Denmark)

    Prince, Kamau; Osadchiy, Alexey Vladimirovich; Tafur Monroy, Idelfonso

    2009-01-01

    We demonstrate a radio over fibre link supporting 256-QAM / 12 Mbaud WiMAX signalling over 118-km long-reach PON with deployed fibre. Our colourless implementation uses commercially-available, low-complexity devices typically used in TDM-PON or WDM-PON.......We demonstrate a radio over fibre link supporting 256-QAM / 12 Mbaud WiMAX signalling over 118-km long-reach PON with deployed fibre. Our colourless implementation uses commercially-available, low-complexity devices typically used in TDM-PON or WDM-PON....

  3. 100km reach DWDM SuperPON with upstream bit rates of 2.5Gb/s and 10Gb/s

    Science.gov (United States)

    Talli, Giuseppe; Townsend, Paul D.

    2005-06-01

    The potential for sharing infrastructure costs between a large number of customers and the high data rates allowed by optical fibres make passive optical networks (PONs) an attractive solution to the problem of upgrading current copper-based access networks. Optically-amplified, long reach, time division multiple access (TDMA) PONs or 'SuperPONs' offer the potential to further reduce bandwidth transport costs by enabling the direct connection of access networks and inner core networks, thereby eliminating the costs of the outer core/metro backhaul network. The use of dense wavelength division multiplexing (DWDM) could also allow sharing the same feeder fibre and PON head end equipment between a number of such TDMA SuperPONs, each working at different ITU-grid wavelengths. However, a cost effective access solution should employ a customer optical network unit (ONU), which is independent of the PON wavelength, or colorless, in order to reduce the high inventory and deployment costs of using expensive, wavelength-specified sources at the customer. In this paper we demonstrate for the first time the use of a monolithically-integrated, electroabsorption modulator-semiconductor optical amplifiers (EAM-SOAs) as a colorless ONU in a high performance DWDM SuperPON system. These compact devices offer the potential for low-cost optoelectronic integration with other ONU components together with the ability to modulate at rates up to 10Gbps and beyond. We have used this approach to investigate the feasibility of supporting up to 17 SuperPONs from a single feeder fibre and PON head end, each of 100km-reach accommodating 512 users at 2.5Gb/s or 128 at 10Gb/s.

  4. MODELAMIENTO DE UN ALGORITMO PARA LA ASIGNACION DE LONGITUDES DE ONDA EN UN MULTIPLEXOR DWDM MINIMIZANDO EL PROCESO DE MEZCLADO DE LA CUARTA ONDA FWM (FOUR WAVE MIXING

    Directory of Open Access Journals (Sweden)

    Jorge Arturo Mojica Cáceres

    2013-07-01

    Full Text Available Uno de los medios de transmisión de alta velocidad más utilizados en nuestro entorno es la fibra óptica especificada en el estándar ITU-T G.625; sin embargo, su despliegue y utilización plantea en la actualidad varios desafíos a resolver debido a su característica de no linealidad, dentro de los cuales se encuentra el relacionado con la disminución del nivel de interferencia. Con el ánimo de brindar un aporte en la solución de esta problemática se propone modelar el comportamiento no lineal de FWM cuando se implementan sistemas de multiplexación de longitudes de onda por un único hilo de fibra óptica a fin de poder estimar las características fundamentales que rige esta tecnología y poder plantear un algoritmo que sea capaz de reducir la interferencia no lineal de cuarta onda (FWM. Como conclusión principal se encontró que el modelo propuesto reduce la interferencia no lineal FWM, lo que permite un aumento en la asignación de canales DWDM aumentando el ancho de banda establecido en cada enlace óptico.

  5. Simultaneous frequency stabilization and high-power dense wavelength division multiplexing (HP-DWDM) using an external cavity based on volume Bragg gratings (VBGs)

    Science.gov (United States)

    Hengesbach, Stefan; Klein, Sarah; Holly, Carlo; Witte, Ulrich; Traub, Martin; Hoffmann, Dieter

    2016-03-01

    Multiplexing technologies enable the development of high-brightness diode lasers for direct industrial applications. We present a High-Power Dense Wavelength Division Multiplexer (HP-DWDM) with an average channel spacing of 1.7 (1.5) nm and a subsequent external cavity mirror to provide feedback for frequency stabilization and multiplexing in one step. The "self-optimizing" multiplexing unit consists of four reflective Volume Bragg Gratings (VBGs) with 99% diffraction efficiency and seven dielectric mirrors to overlay the radiation of five input channels with an adjustable channel spacing of 1-2 nm. In detail, we focus on the analysis of the overall optical efficiency, the change of the beam parameter product and the spectral width. The performance is demonstrated using five 90 μm multimode 9xx single emitters with M2angular intensity distribution changes strongly and the beam parameter product decreases by a factor of 1.2 to 1.9. Thereby the angular intensity distribution is more affected than the width of the beam waist. The spectral width per emitter decreases to 3-200 pm (FWHM) depending on the injection current and the reflectance of the feedback mirror (0.75%, 1.5%, 4%, 6% or 8%). The overall optical multiplexing efficiency ranges between 77% and 86%. With some modifications (e.g. enhanced AR-coatings) we expect 90-95%.

  6. Researching and Discussing On ULH-DWDM Optic Fiber Telecom Key Problems%ULH-DWDM光通信关键技术探析

    Institute of Scientific and Technical Information of China (English)

    江明华

    2014-01-01

    There is no avoidance interfere in telecom transmission media,with the development of technology,people use ULH-DWDM fiber transmission to enhance capacity and distance.It saves much electronic trunk devices, induces much cost,raises system’s transmission quality and ability. The key problems in fiber transmission ,such as magnifying technology,dispersion compensating technology,non-linear cheecking technology,code pattern modulating technology.etc.In this paper,it will analyze and discuss these technologies and their research deeply.%在光通信传输媒体中不可避免存在干扰,随着科技的发达,人们利用ULH-DWDM光传输来提高传输速度、传输容量和传输距离。节省了大量的中继器,减少建设成本,增强系统的质量和可靠度。ULH-DWDM光通信传输系统中有许多的关键技术,如光放大技术、色散补偿技术、非线性抑制、码型调制技术等,本文将对这些技术及其研究动态作深入分析和探讨。

  7. Characterization of RF signal transmission using FSO links considering atmospheric effects

    Science.gov (United States)

    Mohammad Shah, Alam; Dat, Pham Tien; Kazaura, Kamugisha; Wakamori, Kazuhiko; Suzuki, Toshiji; Omae, Kazunori; Matsumoto, Mitsuji; Aburakawa, Yuji; Takahashi, Koichi; Nakamura, Takuya; Higashino, Takeshi; Tsukamoto, Katsutoshi; Komaki, Shozo

    2008-02-01

    Radio on Free-Space Optics (RoFSO) communication systems have attracted a considerable attention for a variety of applications where optical fibers are not feasible, especially in rural areas, to provide ubiquitous wireless services quickly and more effectively. RoFSO links can be used to transmit signals like cellular W-CDMA, terrestrial digital TV or WLAN signals. In spite of its potential, such links are highly dependent on the deployment environment characteristics in particular the weather conditions. Severity and duration of the atmospheric effects have direct impact on the availability of the links as well as on the quality of RF signal transmitted over it. Thus, the necessity of investigating the effects of various weather conditions on RF signal transmission using FSO links. In collaboration with several institutions, we are currently developing an advanced Dense Wavelength Division Multiplexing (DWDM) RoFSO antenna capable of transporting multiple RF signals. As preliminary work, we are conducting experiments on a 1 km link using an off-the-shelf Radio Frequency - FSO (RF-FSO) antenna, with the objective of obtaining and characterizing performance related parameters of RF-FSO transmission in operational environment. As an example, we examine the influence of atmospheric turbulence on the transmission quality of W-CDMA signal. Among the performance metric of interest is the Adjacent Channel Leakage Power Ratio (ACLR) which will be measured, analyzed and correlated with the weather conditions. An atmospheric fluctuation model for estimating the communication quality of RF signal transmission on FSO links is being developed. Also the obtained results will be used for the deployment environment characterization as well as baseline for the design and performance evaluation of new advanced DWDM RoFSO communication systems we are currently developing.

  8. 1.92 Tb/s coherent DWDM-OFDMA-PON with no high-speed ONU-side electronics over 100 km SSMF and 1:64 passive split.

    Science.gov (United States)

    Cvijetic, Neda; Huang, Ming-Fang; Ip, Ezra; Shao, Yin; Huang, Yue-Kai; Cvijetic, Milorad; Wang, Ting

    2011-11-21

    Record 1.92-Tb/s (40λ × 48 Gb/s/λ) coherent DWDM-OFDMA-PON without high-speed ONU-side ADCs/DACs/DSP/RF clock sources is demonstrated over 100 km straight SSMF with a 1:64 passive split. Novel optical-domain OFDMA sub-band selection, coherent detection, and simple RF components are exploited. As the first experimental verification of a next-generation optical platform capable of delivering 1 Gb/s to 1000(+) users over 100 km, the new architecture is promising for future optical access/metro systems. © 2011 Optical Society of America

  9. VCSEL-Based DWDM PON With 4 BIT/S/HZ Spectral Efficiency Using Carrierless Amplitude Phase Modulation

    DEFF Research Database (Denmark)

    Rodes Lopez, Roberto; Wieckowski, Marcin; Pham, Tien Thang

    2011-01-01

    We experimental demonstrate successful performance of VCSEL-based WDM link supporting advanced 16-level carrierless amplitude/phase modulation up to 1.25 Gbps, over 26 km SSMF with spectral efficiency of 4 bit/s/Hz for application in high capacity PONs.......We experimental demonstrate successful performance of VCSEL-based WDM link supporting advanced 16-level carrierless amplitude/phase modulation up to 1.25 Gbps, over 26 km SSMF with spectral efficiency of 4 bit/s/Hz for application in high capacity PONs....

  10. Scandinavian links

    DEFF Research Database (Denmark)

    Matthiessen, Christian Wichmann; Knowles, Richard D.

    2014-01-01

    centres, one joins more thinly populated regions, and the last one links peripheral areas. Two of them (The Great Belt Link and the Oresund Link) have been constructed and are in full operation. The third (the Fehmarnbelt Link) has been decided 2008 on bilateral government level. The three links...

  11. The link in Linking

    Science.gov (United States)

    Caldwell, Jane C; Chiale, Pablo A; Gonzalez, Mario D; Baranchuk, Adrian

    2013-01-01

    We present 2 cases of the slow-fast form of AVNRT with initially narrow QRS complexes followed by sudden unexpected transition to persistently wide QRS complexes due to aberrant intraventricular conduction. Introduction of a properly timed extrastimulus in one case and critical oscillations in cycle length due to short-long coupling in the second case set the stage for the initial bundle branch block. However, persistence of the aberrancy pattern once the initial event abated was maintained by the "linking" phenomenon. Delayed, retrograde concealed activation from the contralateral bundle branch perpetuated the initial bundle branch block. PMID:23840106

  12. Photonic Modulation and Demodulation techniques for Multi-Gb/s Millimetre wave Wireless Links

    OpenAIRE

    Sambaraju -, Rakesh

    2011-01-01

    Los sistemas de radio sobre fibra(Radio Over fibre ROF) ofrecen el ancho de banda y flexibilidad necesario para la generación y distribución de del señales inalámbricas del futuro en una arquitectura de red óptica, que reduce el coste de las redes centralizando el procesado y simplificando la ubicación de la antena (estación de base EB). El uso de sistemas de comunicaciones ópticas como una media de transporte de señales inalámbricas en enlaces RoF reduce el cuello de botella entre los están...

  13. Communication Links

    OpenAIRE

    2003-01-01

    This interactive tutorial helps learners to: Identify key upward, lateral, downward, and informal communication links in their organizations. , Reflect on the benefits, control, satisfaction, information filters, and feedback mechanism of various communication links in the organizations. OCL1000 Communicating Change in Complex Organizations

  14. Operative links

    DEFF Research Database (Denmark)

    Wistoft, Karen

    2010-01-01

    as networks: second, a semantic perspective on discourses and concepts of health, and, third, a health pedagogical perspective on participation, intervention, and roles. This paper argues for the importance of 'operative links' between different levels in health strategies. It is proposed that such links...

  15. Simulink models for performance analysis of high speed DQPSK modulated optical link

    Science.gov (United States)

    Sharan, Lucky; Rupanshi, Chaubey, V. K.

    2016-03-01

    This paper attempts to present the design approach for development of simulation models to study and analyze the transmission of 10 Gbps DQPSK signal over a single channel Peer to Peer link using Matlab Simulink. The simulation model considers the different optical components used in link design with their behavior represented initially by theoretical interpretation, including the transmitter topology, Mach Zehnder Modulator(MZM) module and, the propagation model for optical fibers etc. thus allowing scope for direct realization in experimental configurations. It provides the flexibility to incorporate the various photonic components as either user-defined or fixed and, can also be enhanced or removed from the model as per the design requirements. We describe the detailed operation and need of every component model and its representation in Simulink blocksets. Moreover the developed model can be extended in future to support Dense Wavelength Division Multiplexing (DWDM) system, thereby allowing high speed transmission with N × 40 Gbps systems. The various compensation techniques and their influence on system performance can be easily investigated by using such models.

  16. Simulink models for performance analysis of high speed DQPSK modulated optical link

    Energy Technology Data Exchange (ETDEWEB)

    Sharan, Lucky, E-mail: luckysharan@pilani.bits-pilani.ac.in; Rupanshi,, E-mail: f2011222@pilani.bits-pilani.ac.in; Chaubey, V. K., E-mail: vkc@pilani.bits-pilani.ac.in [EEE Department, BITS-Pilani, Rajasthan, 333031 (India)

    2016-03-09

    This paper attempts to present the design approach for development of simulation models to study and analyze the transmission of 10 Gbps DQPSK signal over a single channel Peer to Peer link using Matlab Simulink. The simulation model considers the different optical components used in link design with their behavior represented initially by theoretical interpretation, including the transmitter topology, Mach Zehnder Modulator(MZM) module and, the propagation model for optical fibers etc. thus allowing scope for direct realization in experimental configurations. It provides the flexibility to incorporate the various photonic components as either user-defined or fixed and, can also be enhanced or removed from the model as per the design requirements. We describe the detailed operation and need of every component model and its representation in Simulink blocksets. Moreover the developed model can be extended in future to support Dense Wavelength Division Multiplexing (DWDM) system, thereby allowing high speed transmission with N × 40 Gbps systems. The various compensation techniques and their influence on system performance can be easily investigated by using such models.

  17. Link Analysis

    Science.gov (United States)

    Donoho, Steve

    Link analysis is a collection of techniques that operate on data that can be represented as nodes and links. This chapter surveys a variety of techniques including subgraph matching, finding cliques and K-plexes, maximizing spread of influence, visualization, finding hubs and authorities, and combining with traditional techniques (classification, clustering, etc). It also surveys applications including social network analysis, viral marketing, Internet search, fraud detection, and crime prevention.

  18. Automated and comprehensive link engineering supporting branched, ring, and mesh network topologies

    Science.gov (United States)

    Farina, J.; Khomchenko, D.; Yevseyenko, D.; Meester, J.; Richter, A.

    2016-02-01

    Link design, while relatively easy in the past, can become quite cumbersome with complex channel plans and equipment configurations. The task of designing optical transport systems and selecting equipment is often performed by an applications or sales engineer using simple tools, such as custom Excel spreadsheets. Eventually, every individual has their own version of the spreadsheet as well as their own methodology for building the network. This approach becomes unmanageable very quickly and leads to mistakes, bending of the engineering rules and installations that do not perform as expected. We demonstrate a comprehensive planning environment, which offers an efficient approach to unify, control and expedite the design process by controlling libraries of equipment and engineering methodologies, automating the process and providing the analysis tools necessary to predict system performance throughout the system and for all channels. In addition to the placement of EDFAs and DCEs, performance analysis metrics are provided at every step of the way. Metrics that can be tracked include power, CD and OSNR, SPM, XPM, FWM and SBS. Automated routine steps assist in design aspects such as equalization, padding and gain setting for EDFAs, the placement of ROADMs and transceivers, and creating regeneration points. DWDM networks consisting of a large number of nodes and repeater huts, interconnected in linear, branched, mesh and ring network topologies, can be designed much faster when compared with conventional design methods. Using flexible templates for all major optical components, our technology-agnostic planning approach supports the constant advances in optical communications.

  19. Transatlantic link

    Science.gov (United States)

    (left) European Geophysical Society (EGS) President Rolf Meissner at AGU Headquarters with (center) Executive Director Fred Spilhaus and (right) Foreign Secretary Juan Roederer. Meissner attended the meeting of AGU's Committee on International Participation (CIP) on February 26, 1988. At that meeting, specific ways of fostering close links between AGU and EGS were discussed.A few weeks later, Roederer and AGU staff, working with EGS Secretary-General Arne Richter at the EGS meeting in Bologna, Italy, March 21-25, planned details of the establishment of an AGU office in Europe. The Copernicus Gesellschaft, a new entity located on the premises of the Max Planck Institute for Aeronomy in Lindau, Federal Republic of Germany, will provide the administrative staff and handle logistics.

  20. Dancing links

    CERN Document Server

    Knuth, Donald E

    2009-01-01

    The author presents two tricks to accelerate depth-first search algorithms for a class of combinatorial puzzle problems, such as tiling a tray by a fixed set of polyominoes. The first trick is to implement each assumption of the search with reversible local operations on doubly linked lists. By this trick, every step of the search affects the data incrementally. The second trick is to add a ghost square that represents the identity of each polyomino. Thus puts the rule that each polyomino be used once on the same footing as the rule that each square be covered once. The coding simplifies to a more abstract form which is equivalent to 0-1 integer programming. More significantly for the total computation time, the search can naturally switch between placing a fixed polyomino or covering a fixed square at different stages, according to a combined heuristic. Finally the author reports excellent performance for his algorithm for some familiar puzzles. These include tiling a hexagon by 19 hexiamonds and the N queen...

  1. DWDM Devices Based on Planar Waveguide Technologies

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A review is presented on some of our recent results for designs, simulations and fabrication of several photonic integrated devices, such as arrayed-waveguide gratings (AWGs) and etched diffraction gratings (EDGs), based on planar waveguide technologies. Some novel designs for flat-top AWGs and EDGs with flat-top spectral responses are presented.

  2. Sex-linked dominant

    Science.gov (United States)

    Inheritance - sex-linked dominant; Genetics - sex-linked dominant; X-linked dominant; Y-linked dominant ... can be either an autosomal chromosome or a sex chromosome. It also depends on whether the trait ...

  3. Linked alternating forms and linked symplectic Grassmannians

    CERN Document Server

    Osserman, Brian

    2011-01-01

    Motivated by applications to higher-rank Brill-Noether theory and the Bertram-Feinberg-Mukai conjecture, we introduce the concepts of linked alternating and linked symplectic forms on a chain of vector bundles, and show that the linked symplectic Grassmannians parametrizing chains of subbundles isotropic for a given linked symplectic form has good dimensional behavior analogous to that of the classical symplectic Grassmannian.

  4. Towards convergence of wireless and wireline signal transport in broadband access networks

    DEFF Research Database (Denmark)

    Yu, Xianbin; Prince, Kamau; Tafur Monroy, Idelfonso

    2010-01-01

    Hybrid optical wireless access networks are to play an important role in the realization of the vision of delivery of broadband services to the end-user any time, anywhere and at affordable costs. We present results of experiments conducted over a field deployed optical fibre links we successfull...... demonstrated converged wireless and wireline signal transport over a common fibre infrastructure. The type of signal used in this field deployed experiments cover WiMax, Impulse-radio ultra-wideband (UWB) and coherent transmission of baseband QPSK and radio-over-fibre signals....

  5. Linked data management

    CERN Document Server

    Hose, Katja; Schenkel, Ralf

    2014-01-01

    Linked Data Management presents techniques for querying and managing Linked Data that is available on today’s Web. The book shows how the abundance of Linked Data can serve as fertile ground for research and commercial applications. The text focuses on aspects of managing large-scale collections of Linked Data. It offers a detailed introduction to Linked Data and related standards, including the main principles distinguishing Linked Data from standard database technology. Chapters also describe how to generate links between datasets and explain the overall architecture of data integration systems based on Linked Data. A large part of the text is devoted to query processing in different setups. After presenting methods to publish relational data as Linked Data and efficient centralized processing, the book explores lookup-based, distributed, and parallel solutions. It then addresses advanced topics, such as reasoning, and discusses work related to read-write Linked Data for system interoperation. Desp...

  6. Weierstrass polynomials for links

    DEFF Research Database (Denmark)

    Hansen, Vagn Lundsgaard

    1997-01-01

    There is a natural way of identifying links in3-space with polynomial covering spaces over thecircle. Thereby any link in 3-space can be definedby a Weierstrass polynomial over the circle. Theequivalence relation for covering spaces over thecircle is, however, completely different from...... that for links in 3-space. This paper initiates a study of the connections between polynomial covering spaces over the circle and links in 3-space....

  7. The ALMA high speed optical communication link is here: an essential component for reliable present and future operations

    Science.gov (United States)

    Filippi, G.; Ibsen, J.; Jaque, S.; Liello, F.; Ovando, N.; Astudillo, A.; Parra, J.; Saldias, Christian

    2016-07-01

    Announced in 2012, started in 2013 and completed in 2015, the ALMA high bandwidth communication system has become a key factor to achieve the operational and scientific goals of ALMA. This paper summarizes the technical, organizational, and operational goals of the ALMA Optical Link Project, focused in the creation and operation of an effective and sustainable communication infrastructure to connect the ALMA Operations Support Facility and Array Operations Site, both located in the Atacama Desert in the Northern region of Chile, with the point of presence of REUNA in Antofagasta, about 400km away, and from there to the Santiago Central Office in the Chilean capital through the optical infrastructure created by the EC-funded EVALSO project and now an integral part of the REUNA backbone. This new infrastructure completed in 2014 and now operated on behalf of ALMA by REUNA, the Chilean National Research and Education Network, uses state of the art technologies, like dark fiber from newly built cables and DWDM transmission, allowing extending the reach of high capacity communication to the remote region where the Observatory is located. The paper also reports on the results obtained during the first year and a half testing and operation period, where different operational set ups have been experienced for data transfer, remote collaboration, etc. Finally, the authors will present a forward look of the impact of it to both the future scientific development of the Chajnantor Plateau, where many installations area are (and will be) located, as well as the potential Chilean scientific backbone long term development.

  8. Linking open vocabularies

    CERN Document Server

    Greifender, Elke; Seadle, Michael

    2013-01-01

    Linked Data (LD), Linked Open Data (LOD) and generating a web of data, present the new knowledge sharing frontier. In a philosophical context, LD is an evolving environment that reflects humankinds' desire to understand the world by drawing on the latest technologies and capabilities of the time. LD, while seemingly a new phenomenon did not emerge overnight; rather it represents the natural progression by which knowledge structures are developed, used, and shared. Linked Open Vocabularies is a significant trajectory of LD. Linked Open Vocabularies targets vocabularies that have traditionally b

  9. Let's "Downscale" Linked Data

    NARCIS (Netherlands)

    Gueret, Christophe; de Boer, Victor; Schlobach, Stefan

    2014-01-01

    Open data policies and linked data publication are powerful tools for increasing transparency, participatory governance, and accountability. A closer look at linked data technologies, however, proves that their design and deployment exclude the majority of the world’s population. It will take small

  10. Typed links in Webvise

    DEFF Research Database (Denmark)

    1999-01-01

    We extended the Webvise open hypermedia system with support for typed links.  The ECDL'99 paper describes these extensions.......We extended the Webvise open hypermedia system with support for typed links.  The ECDL'99 paper describes these extensions....

  11. Il progetto Linked Heritage

    Directory of Open Access Journals (Sweden)

    Marzia Piccininno

    2013-03-01

    Full Text Available ItLinked Heritage è uno dei progetti di punta finanziati dalla Commissione europea per alimentare Europeana, il portale dei contenuti culturali digitali europei. Linked Heritage raccoglie, sotto il coordinamento dell’ICCU, un consorzio molto vasto i cui partner provengono da quasi tutti i paesi dell’Unione più Russia e Israele; essi forniranno a Europeana ben 3 milioni di risorse digitali. Oltre al tema dell’aggregazione di contenuti culturali digitali, Linked Heritage sta esplorando altri temi fondamentali per Europeana come il multilinguismo, i linked data e il rapporto con possibili partner commerciali. Linked Heritage è l’ultimo in ordine di tempo di una serie di iniziative progettuali avviate da un consorzio europeo di istituzioni che opera insieme da oltre dieci anni nell’ambito del patrimonio culturale digitale.EnLinked Heritage is one of the flagship projects funded by the European commission to feed Europeana, the portal of the European digital cultural content. Linked Heritage has a very large partnership, coordinated by ICCU, whose members come from many European countries, Russia and Israel; they will supply Europeana with 3 million digital resources. Beyond the aggregation of digital cultural content, Linked Heritage is exploring other topics which are essential for Europeana, like multilingualism, linked data and the relationship with the commercial partners. Linked Heritage is the last one in time of a series of projects made up by a European consortium of institutions that has been working for over ten years in the field of digital cultural heritage.

  12. Dynamical fat link fermions

    CERN Document Server

    Kamleh, W; Williams, A G; Kamleh, Waseem; Leinweber, Derek B.; Williams, Anthony G.; 10.1016/j.nuclphysbps.2003.12.058

    2004-01-01

    The use of APE smearing or other blocking techniques in fermion actions can provide many advantages. There are many variants of these fat link actions in lattice QCD currently, such as FLIC fermions. Frequently, fat link actions make use of the APE blocking technique in combination with a projection of the blocked links back into the special unitary group. This reunitarisation is often performed using an iterative maximisation of a gauge invariant measure. This technique is not differentiable with respect to the gauge field and thus prevents the use of standard Hybrid Monte Carlo simulation algorithms. The use of an alternative projection technique circumvents this difficulty and allows the simulation of dynamical fat link fermions with standard HMC and its variants.

  13. Link to paper

    Data.gov (United States)

    U.S. Environmental Protection Agency — Link to the paper. This dataset is associated with the following publication: Naile, J., A.W. Garrison, J. Avants, and J. Washington. Isomers/enantiomers of...

  14. Latest Research: Genetic Links

    Science.gov (United States)

    ... Current Issue Past Issues Feature: Vision Latest Research: Genetic Links Past Issues / Summer 2008 Table of Contents ... inside the eye is a risk factor for glaucoma. Summer 2008 Issue: Volume 3 Number 3 Page ...

  15. Linked Ocean Data

    Science.gov (United States)

    Leadbetter, Adam; Arko, Robert; Chandler, Cynthia; Shepherd, Adam

    2014-05-01

    "Linked Data" is a term used in Computer Science to encapsulate a methodology for publishing data and metadata in a structured format so that links may be created and exploited between objects. Berners-Lee (2006) outlines the following four design principles of a Linked Data system: Use Uniform Resource Identifiers (URIs) as names for things. Use HyperText Transfer Protocol (HTTP) URIs so that people can look up those names. When someone looks up a URI, provide useful information, using the standards (Resource Description Framework [RDF] and the RDF query language [SPARQL]). Include links to other URIs so that they can discover more things. In 2010, Berners-Lee revisited his original design plan for Linked Data to encourage data owners along a path to "good Linked Data". This revision involved the creation of a five star rating system for Linked Data outlined below. One star: Available on the web (in any format). Two stars: Available as machine-readable structured data (e.g. An Excel spreadsheet instead of an image scan of a table). Three stars: As two stars plus the use of a non-proprietary format (e.g. Comma Separated Values instead of Excel). Four stars: As three stars plus the use of open standards from the World Wide Web Commission (W3C) (i.e. RDF and SPARQL) to identify things, so that people can point to your data and metadata. Five stars: All the above plus link your data to other people's data to provide context Here we present work building on the SeaDataNet common vocabularies served by the NERC Vocabulary Server, connecting projects such as the Rolling Deck to Repository (R2R) and the Biological and Chemical Oceanography Data Management Office (BCO-DMO) and other vocabularies such as the Marine Metadata Interoperability Ontology Register and Repository and the NASA Global Change Master Directory to create a Linked Ocean Data cloud. Publishing the vocabularies and metadata in standard RDF XML and exposing SPARQL endpoints renders them five-star Linked

  16. Links, Exchanges, Sharing.

    Science.gov (United States)

    Shearer, James

    1992-01-01

    Describes the international activities of the Thames Valley University's Department of Information Management, including formal academic links with overseas institutions, development of short courses for practitioners, discussion meetings, staff and student visits, and enrollment of international students. Topics addressed include personnel,…

  17. Response model parameter linking

    NARCIS (Netherlands)

    Barrett, Michelle Derbenwick

    2015-01-01

    With a few exceptions, the problem of linking item response model parameters from different item calibrations has been conceptualized as an instance of the problem of equating observed scores on different test forms. This thesis argues, however, that the use of item response models does not require

  18. Linking Literacy and Movement

    Science.gov (United States)

    Pica, Rae

    2010-01-01

    There are many links between literacy and movement. Movement and language are both forms of communication and self-expression. Rhythm is an essential component of both language and movement. While people may think of rhythm primarily in musical terms, there is a rhythm to words and sentences as well. Individuals develop an internal rhythm when…

  19. Linking place and mind

    DEFF Research Database (Denmark)

    Jensen, Marie Møller

    2016-01-01

    This paper investigates the salience of vernacular Tyneside forms on the basis of theories of enregisterment and exemplar processing. On one level, exemplar theory provides a psycholinguistic account of how the link between social value and linguistic features is possible. Conversely, integrating...

  20. Link Influence Entropy

    Science.gov (United States)

    Singh, Priti; Chakraborty, Abhishek; Manoj, B. S.

    2017-01-01

    In this paper we propose a new metric, Link Influence Entropy (LInE), which describes importance of each node based on the influence of each link present in a network. Influence of a link can neither be effectively estimated using betweenness centrality nor using degree based probability measures. The proposed LInE metric which provides an effective way to estimate the influence of a link in the network and incorporates this influence to identify nodal characteristics, performs better compared to degree based entropy. We found that LInE can differentiate various network types which degree-based or betweenness centrality based node influence metrics cannot. Our findings show that spatial wireless networks and regular grid networks, respectively, have lowest and highest LInE values. Finally, performance analysis of LInE is carried out on a real-world network as well as on a wireless mesh network testbed to study the influence of our metric as well as influence stability of nodes in dynamic networks.

  1. Secure Link Middleware

    Science.gov (United States)

    2008-08-01

    Secure Link middleware as specified by the circled ‘sld’, sld . Using a network traffic analyzer (e.g., tcpdump) at router bulldog and tiger, ARL...or nfs (remote accessing file systems) to be securely operated and used among networked computer systems without any bulldog (router3) bear (router2

  2. Volumes of chain links

    CERN Document Server

    Kaiser, James; Rollins, Clint

    2011-01-01

    Agol has conjectured that minimally twisted n-chain links are the smallest volume hyperbolic manifolds with n cusps, for n at most 10. In his thesis, Venzke mentions that these cannot be smallest volume for n at least 11, but does not provide a proof. In this paper, we give a proof of Venzke's statement. The proof for n at least 60 is completely rigorous. The proof for n between 11 and 59 uses a computer calculation, and can be made rigorous for manifolds of small enough complexity, using methods of Moser and Milley. Finally, we prove that the n-chain link with 2m or 2m+1 half-twists cannot be the minimal volume hyperbolic manifold with n cusps, provided n is at least 60 or |m| is at least 8, and we give computational data indicating this remains true for smaller n and |m|.

  3. Linking assumptions in amblyopia

    Science.gov (United States)

    LEVI, DENNIS M.

    2017-01-01

    Over the last 35 years or so, there has been substantial progress in revealing and characterizing the many interesting and sometimes mysterious sensory abnormalities that accompany amblyopia. A goal of many of the studies has been to try to make the link between the sensory losses and the underlying neural losses, resulting in several hypotheses about the site, nature, and cause of amblyopia. This article reviews some of these hypotheses, and the assumptions that link the sensory losses to specific physiological alterations in the brain. Despite intensive study, it turns out to be quite difficult to make a simple linking hypothesis, at least at the level of single neurons, and the locus of the sensory loss remains elusive. It is now clear that the simplest notion—that reduced contrast sensitivity of neurons in cortical area V1 explains the reduction in contrast sensitivity—is too simplistic. Considerations of noise, noise correlations, pooling, and the weighting of information also play a critically important role in making perceptual decisions, and our current models of amblyopia do not adequately take these into account. Indeed, although the reduction of contrast sensitivity is generally considered to reflect “early” neural changes, it seems plausible that it reflects changes at many stages of visual processing. PMID:23879956

  4. Collaboratively Patching Linked Data

    CERN Document Server

    Knuth, Magnus; Sack, Harald

    2012-01-01

    Today's Web of Data is noisy. Linked Data often needs extensive preprocessing to enable efficient use of heterogeneous resources. While consistent and valid data provides the key to efficient data processing and aggregation we are facing two main challenges: (1st) Identification of erroneous facts and tracking their origins in dynamically connected datasets is a difficult task, and (2nd) efforts in the curation of deficient facts in Linked Data are exchanged rather rarely. Since erroneous data often is duplicated and (re-)distributed by mashup applications it is not only the responsibility of a few original publishers to keep their data tidy, but progresses to be a mission for all distributers and consumers of Linked Data too. We present a new approach to expose and to reuse patches on erroneous data to enhance and to add quality information to the Web of Data. The feasibility of our approach is demonstrated by example of a collaborative game that patches statements in DBpedia data and provides notifications ...

  5. X linked mental retardation.

    Science.gov (United States)

    Rejeb, Imen; Ben Jemaa, Lamia; Chaabouni, Habiba

    2009-05-01

    Mental retardation (MR) is a group of heterogeneous clinical conditions. There are more than 900 genetic disorders associated with MR and it affects around 3% of the general population. Many MR conditions described are syndromic, fragile X syndrome being the most common clinical entity among them. X linked mental retardation (XLMR) is subdivided in two categories: syndromic XLMR (MRXS) when MR is associated with clinical features and non-syndromic XLMR (MRX) when MR is isolated. The aim of this systematic review of the literature was to join together the results of several studies related to X linked mental retardation and to present various genes implicated in this disease. In this review, focus has been given on genes implicated in mental retardation, the clinical data and on phenotype-genotype correlations. An exhaustive electronic and library research of the recent literature was carried out on the Web sites "Science Direct" and "Interscience Wiley". The key words used were "mental retardation", "X chromosome", "gene", "syndromic mental retardation", "non-syndromic mental retardation". In this review a number of X linked genes, the clinical features associated with the gene abnormality, and the prevalence of the disease gene are discussed. We classified these genes by order of their first implication in MR. A table presented on the XLMR Update Web site who list the 82 known XLMR genes is available as XLMR Genes and corresponding proteins.

  6. Knots and links

    CERN Document Server

    Rolfsen, Dale

    2003-01-01

    Rolfsen's beautiful book on knots and links can be read by anyone, from beginner to expert, who wants to learn about knot theory. Beginners with a basic background find an inviting introduction to the elements of topology, emphasizing the tools needed for understanding knots, the fundamental group and van Kampen's theorem, for example, which are then applied to concrete problems, such as computing knot groups. For experts, Rolfsen explains advanced topics, such as the connections between knot theory and surgery and how they are useful to understanding three-manifolds. Besides providing a guide

  7. The weakest link

    Energy Technology Data Exchange (ETDEWEB)

    Lumley, G. [GBI Consulting, Qld. (Australia)

    2005-08-01

    In part seven of his series on dragline productivity, the author tackles the subject of the dump rope, the weakest link in the operation of the dragline, is traded. Five factors have been identified as critical to dump life: ratio of dump block to dump rope diameter; excessive loads in dumps rope; rope abrasion against dump block; rope abrasion against bucket; dump rope construction. These factors are considered in the article. The author comments that in the drive to increase dragline productivity, rope life has been sacrificed. 4 figs., 1 tab.

  8. Linking consumer experiences

    DEFF Research Database (Denmark)

    Smed, Karina Madsen

    Consumers consume products in various ways serving a number of purposes. Much attention has been paid to experiences attached to consumption, sometimes very explicitly, e.g. in tourism, the essence of which is experiences of various sorts, but often also implicitly as internalised experiences...... become part of the individual self, worldview, and behaviour. This paper seeks to explore links between consumer experiences through the exploration of narrative sequences in travel blogs. Findings indicate that non-consumption is a central element to the bloggers and also indicative of a community...

  9. EEE Links. Volume 5

    Science.gov (United States)

    Humphrey, Robert (Editor)

    1999-01-01

    The EEE Links Newsletter is a quarterly publication produced by Code 562 in support of the NASA HQ funded NASA Electronic Parts and Packaging (NEPP) Program. The newsletter is produced as an electronic format deliverable made available via the referenced www site administered by Code 562, The newsletter publishes brief articles on topics of interest to NASA programs and projects in the area of electronic parts and packaging. The newsletter does not provide information pertaining to patented or proprietary information. The information provided is at the level of that produced by industry and university researchers and is published at national and international conferences.

  10. Single Carrier Architecture for High Data Rate Wireless PAN Communications System

    CERN Document Server

    Rakotondrainibe, Lahatra; Zaharia, Gheorghe; Grunfelder, Guy; Zein, Ghaïs El

    2010-01-01

    A 60 GHz wireless Gigabit Ethernet (G.E.) communication system is developed at IETR. As the 60 GHz radio link operates only in a single-room configuration, an additional Radio over Fibre (RoF) link is used to ensure the communications in all the rooms of a residential environment. The realized system covers 2 GHz bandwidth. Due to the hardware constraints, a symbol rate at 875 Mbps is attained using simple single carrier architecture. In the baseband (BB) processing block, an original byte/frame synchronization process is designed to provide a smaller value of the preamble missing detection and false alarm probabilities. Bit error rate (BER) measurements have been realized in a large gym for line-of-sight (LOS) conditions. A Tx-Rx distance greater than 30 meters was attained with low BER using high gain antennas and forward error correction RS (255, 239) coding.

  11. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... Projects » Learn the Link - Drugs and HIV Learn the Link - Drugs and HIV Email Facebook Twitter 2005 – ... and to help us Send the Message . Get the Facts What are HIV and AIDS? HIV (human ...

  12. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... the link between drug abuse and HIV infection. It contains information for young people, parents and teachers, ... present time. The virus (HIV) and the disease it causes (AIDS) are often linked and referred to ...

  13. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... the Link - Drugs and HIV Learn the Link - Drugs and HIV Email Facebook Twitter 2005 –Ongoing Behaviors ... GA: CDC, DHHS. Retrieved June 2012 How are Drug Abuse and HIV Related? Drug abuse and addiction ...

  14. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... the Link - Drugs and HIV Learn the Link - Drugs and HIV Email Facebook Twitter 2005 –Ongoing Behaviors ... GA: CDC, DHHS. Retrieved June 2012 How are Drug Abuse and HIV Related? Drug abuse and addiction ...

  15. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... the link between drug abuse and HIV infection. It contains information for young people, parents and teachers, ... present time. The virus (HIV) and the disease it causes (AIDS) are often linked and referred to ...

  16. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... Projects » Learn the Link - Drugs and HIV Learn the Link - Drugs and HIV Email Facebook Twitter 2005 – ... and to help us Send the Message . Get the Facts What are HIV and AIDS? HIV (human ...

  17. Monolithic DWDM Multi-channel planar waveguide laser

    DEFF Research Database (Denmark)

    Sckerl, Mads W.; Guldberg-Kjær, Søren Andreas; Laurent-Lund, Christian

    1999-01-01

    silica -on-silicon-based multi-channel waveguide laser with four outputs channel with ~ 50 GHz spacing is presented. Excellent control over channel positions and spacings is obtained by the method presented here. Remarkable temperature tuning properties have been obtained.......silica -on-silicon-based multi-channel waveguide laser with four outputs channel with ~ 50 GHz spacing is presented. Excellent control over channel positions and spacings is obtained by the method presented here. Remarkable temperature tuning properties have been obtained....

  18. Technologies for all-optical wavelength conversion in DWDM networks

    DEFF Research Database (Denmark)

    Wolfson, David; Fjelde, Tina; Kloch, Allan

    2001-01-01

    Different techniques for all-optical wavelength conversion are reviewed and the advantages and disadvantages seen from a system perspective are highlighted. All-optical wavelength conversion will play a major role in making cost-effective network nodes in future high-speed WDM networks, where fun...

  19. Experimental performance of DWDM quadruple Vernier racetrack resonators.

    Science.gov (United States)

    Boeck, Robert; Flueckiger, Jonas; Chrostowski, Lukas; Jaeger, Nicolas A F

    2013-04-08

    We demonstrate that one can meet numerous commercial requirements for filters used in dense wavelength-division multiplexing applications using quadruple Vernier racetrack resonators in the silicon-on-insulator platform. Experimental performance shows a ripple of 0.2 dB, an interstitial peak suppression of 39.7 dB, an adjacent channel isolation of 37.2 dB, an express channel isolation of 10.2 dB, and a free spectral range of 37.52 nm.

  20. Coherent DWDM technology for high speed optical communications

    Science.gov (United States)

    Saunders, Ross

    2011-10-01

    The introduction of coherent digital optical transmission enables a new generation of high speed optical data transport and fiber impairment mitigation. An initial implementation of 40 Gb/s coherent systems using Dual Polarization Quadrature Phase Shift Keying (DP-QPSK) is already being installed in carrier networks. New systems running at 100 Gb/s DP-QPSK data rate are in development and early technology lab and field trial phase. Significant investment in the 100 Gb/s ecosystem (optical components, ASICs, transponders and systems) bodes well for commercial application in 2012 and beyond. Following in the footsteps of other telecommunications fields such as wireless and DSL, we can expect coherent optical transmission to evolve from QPSK to higher order modulations schemes such as Mary PSK and/or QAM. This will be an interesting area of research in coming years and poses significant challenges in terms of electro-optic, DSP, ADC/DAC design and fiber nonlinearity mitigation to reach practical implementation ready for real network deployments.

  1. Semi-empirical system scaling rules for DWDM system design.

    Science.gov (United States)

    DeMuth, Brian; Frankel, Michael Y; Pelekhaty, Vladimir

    2012-01-30

    Recently, several theoretical papers have derived relationships for fiber-optic transmission system performance in terms of associated physical layer parameters. At the same time, a large number of detailed experiments have been and continue being performed that demonstrate increasing capacities and unregenerated reach. We use this wealth of experimental data to validate the aforementioned relationships, and to propose a set of simple scaling rules for performance. We find that, despite substantial differences in experimental configurations, overall performance in terms of spectral efficiency and unregenerated reach is well explained by scaling rules. These scaling rules will be useful to carriers seeking to understand what they should expect to see in terms of network performance using deployed or easily accessible technology, which may be radically different from hero experiment results. These rules will also be useful to design engineers seeking cost effective tradeoffs to achieving higher performance using realistic upgrade strategies, and what might be encountered as a fundamental limit.

  2. Nanoimprinted DWDM laser arrays on indium phosphide substrates

    DEFF Research Database (Denmark)

    Smistrup, Kristian; Nørregaard, Jesper; Mironov, Andrej

    2014-01-01

    shift in the grating, and are single mode with high side-mode suppression. Typically, such lasers are patterned using e-beam lithography (EBL). We present a fabrication method based on patterning by thermal nanoimprint lithography, which is potentially less costly and faster than EBL. Thermal...

  3. ITK optical links backup document

    CERN Document Server

    Huffman, B T; The ATLAS collaboration; Flick, T; Ye, J

    2013-01-01

    This document describes the proposed optical links to be used for the ITK in the phase II upgrade. The current R&D for optical links pursued in the Versatile Link group is reviewed. In particular the results demonstrating the radiation tolerance of all the on-detector components are documented. The bandwidth requirements and the resulting numerology are given.

  4. Hyperbolic semi-adequate links

    OpenAIRE

    Futer, David; Kalfagianni, Efstratia; Purcell, Jessica S.

    2013-01-01

    We provide a diagrammatic criterion for semi-adequate links to be hyperbolic. We also give a conjectural description of the satellite structures of semi-adequate links. One application of our result is that the closures of sufficiently complicated positive braids are hyperbolic links.

  5. Martel's links with USA

    Directory of Open Access Journals (Sweden)

    Trevor Shaw

    1997-01-01

    Full Text Available Of the 29% foreign members in the Société de Spéléologie, five lived in USA. They were Luella Owen (the only woman member of the Société, R. Ellsworth Cali, H.C. Hovey, E Van Epps and C. R. Blackall. E.S. Balch, though not a member, also knew Martel. These members, between them, published ten papers in Spelunca, which also reviewed their other work. The activities of these six, and their links with France, are discussed. Martel actively encouraged cave work in America, as elsewhere, and Hovey, who had been with him during the survey of Aven Armand, he knew quite well. In 1912 Martel at last visited USA himself and the barometer readings he took in Mamoth Cave to measure altitude enabled him to draw the first longitudinal section of the cave since 1835.

  6. Linking place and mind

    DEFF Research Database (Denmark)

    Jensen, Marie Møller

    2016-01-01

    This paper investigates the salience of vernacular Tyneside forms on the basis of theories of enregisterment and exemplar processing. On one level, exemplar theory provides a psycholinguistic account of how the link between social value and linguistic features is possible. Conversely, integrating...... the notion of social value into exemplar theory extends the value of this originally cognitive theory to social domains. It is suggested that the association of social value and particular local, linguistic forms may contribute to the salience of these forms among local speakers. The empirical work reported...... here takes the form of a questionnaire study, which aims to uncover Tyneside inhabitants' awareness of forms as well as their affiliation with the local community. Results showed differences in frequency perceptions between participants themselves and others which indicate that speakers can identify...

  7. Linking to the Future

    Science.gov (United States)

    Moore, John W.

    1999-09-01

    of JCE in the mail each month, and I expect you do too. I can glance at the cover to get an overview of an issue's content, and I usually am enticed inside by intriguing cover art. I can scan the table of contents to find articles I want to read, or I can just browse through the issue to see what looks interesting. Usually the editors have juxtaposed related articles so that I often find a small treasure trove. The printed Journal is quite portable and can be read in a car or airplane. It will last a long time, and until the paper deteriorates, I will never have a problem reading back issues. I have almost every issue from the first day I subscribed and have even added some older ones from collections of retired colleagues who no longer had shelf space for them. I certainly would not want to give up my printed copies, and I want to keep getting them. I find that JCE Online provides a different kind of resource that is equally valuable. It contains more information, and information that is more appropriate in electronic form. It links related ideas into a much more complex web of information than is possible in print. And it opens pathways to lots of information that is not part of JCE but resides elsewhere. Using this issue as an example, let's take a tour of what JCE Online can do. Point your Web browser to http://jchemed.chem.wisc.edu Click on Journal and then on Current Issue (unless September 1999 is no longer the current issue, in which case you will find it in Past Issues). In the table of contents, find the article "UV Catalysis, Cyanotype Photography, and Sunscreens". Click on the title. When the abstract appears, click on Full Text (PDF) to see the article, just as it appears on page 1199 in this issue. When you are prompted, enter the name and subscriber number from your address label. At the end of the article you will find that supplementary materials are available (including a procedure for testing sunscreens) and you can click on the link to view them

  8. [Hospitals as vital links].

    Science.gov (United States)

    Klink, A

    2013-01-01

    The reform of the system in 2006 aimed at reducing waiting lists in an efficient manner. Performance-linked funding and regulated competition did indeed lead to improved efficiency. The other side of the coin is overtreatment, and expensive and not infrequently damaging growth in volume. In order to control costs, three strategies have been determined: agreements with an annual cap on volume; (b) collaboration of regional health-care providers with the mission of improving results in health care (with profit-sharing if costs fall); and (c) fusions reducing the number of hospitals which reduces the burden of injuries (supply no longer creates its own demand). This article comments on these strategies. The author argues for a fourth approach: if the quality of health care improves, the number of complications will fall, overtreatment will decline and the outcome will be a decrease in burden of injuries. This requires the health care insurers to modify the way they manage their contracts and methods of payment, and stimulates competition based on quality.

  9. Use of Balanced Detection Scheme for Long Haul Optical Duobinary Links

    Directory of Open Access Journals (Sweden)

    Santosh Jagtap

    2014-03-01

    Full Text Available This paper investigates the use of balanced detection for a 32 channel duobinary modulated Dense Wavelength Division Multiplexing (DWDM system with 40Gbps per channel, that is, a total capacity of 1.28Tbps for a repeaterless transmission distance upto 1,680km. We compare the performance of the system using both direct and balanced detection schemes at the receiver and it is found that balanced detection gives higher OSNR at the receiver which leads to an improvement in Q factor of around 0.5 dB. The paper also investigates the robustness of the duobinary modulation format to chromatic dispersion and Four Wave Mixing (FWM.

  10. Protective link for superconducting coil

    Science.gov (United States)

    Umans, Stephen D.

    2009-12-08

    A superconducting coil system includes a superconducting coil and a protective link of superconducting material coupled to the superconducting coil. A rotating machine includes first and second coils and a protective link of superconducting material. The second coil is operable to rotate with respect to the first coil. One of the first and second coils is a superconducting coil. The protective link is coupled to the superconducting coil.

  11. Using ATM over SATCOM links

    Science.gov (United States)

    Comparetto, Gary M.

    1995-01-01

    The Asynchronous Transfer Mode (ATM) protocol is studied from the standpoint of determining what limitations, if any, exist in using it over satellite links. It is concluded that, while there is nothing intrinsic about ATM that would generally preclude its use over satellite links, there are, however, several intrinsic characteristics of satellite links, as well as some satellite system configuration-specific issues, that must be taken into account.

  12. "Conjectural" links in complex networks

    Science.gov (United States)

    Snarskii, A. A.; Zorinets, D. I.; Lande, D. V.

    2016-11-01

    This paper introduces the concept of Conjectural Link for Complex Networks, in particular, social networks. Conjectural Link we understand as an implicit link, not available in the network, but supposed to be present, based on the characteristics of its topology. It is possible, for example, when in the formal description of the network some connections are skipped due to errors, deliberately hidden or withdrawn (e.g. in the case of partial destruction of the network). Introduced a parameter that allows ranking the Conjectural Link. The more this parameter - the more likely that this connection should be present in the network. This paper presents a method of recovery of partially destroyed Complex Networks using Conjectural Links finding. Presented two methods of finding the node pairs that are not linked directly to one another, but have a great possibility of Conjectural Link communication among themselves: a method based on the determination of the resistance between two nodes, and method based on the computation of the lengths of routes between two nodes. Several examples of real networks are reviewed and performed a comparison to know network links prediction methods, not intended to find the missing links in already formed networks.

  13. Link Clustering with Extended Link Similarity and EQ Evaluation Division.

    Directory of Open Access Journals (Sweden)

    Lan Huang

    Full Text Available Link Clustering (LC is a relatively new method for detecting overlapping communities in networks. The basic principle of LC is to derive a transform matrix whose elements are composed of the link similarity of neighbor links based on the Jaccard distance calculation; then it applies hierarchical clustering to the transform matrix and uses a measure of partition density on the resulting dendrogram to determine the cut level for best community detection. However, the original link clustering method does not consider the link similarity of non-neighbor links, and the partition density tends to divide the communities into many small communities. In this paper, an Extended Link Clustering method (ELC for overlapping community detection is proposed. The improved method employs a new link similarity, Extended Link Similarity (ELS, to produce a denser transform matrix, and uses the maximum value of EQ (an extended measure of quality of modularity as a means to optimally cut the dendrogram for better partitioning of the original network space. Since ELS uses more link information, the resulting transform matrix provides a superior basis for clustering and analysis. Further, using the EQ value to find the best level for the hierarchical clustering dendrogram division, we obtain communities that are more sensible and reasonable than the ones obtained by the partition density evaluation. Experimentation on five real-world networks and artificially-generated networks shows that the ELC method achieves higher EQ and In-group Proportion (IGP values. Additionally, communities are more realistic than those generated by either of the original LC method or the classical CPM method.

  14. Game Changer: Linked Learning Detroit

    Science.gov (United States)

    ConnectEd: The California Center for College and Career, 2016

    2016-01-01

    JP Morgan Chase joins the Skillman Foundation, the Ford Foundation, and the Ford Motor Company Fund, whose grants total $7 million and will connect 10,000 Detroit high school students to career education and work experiences over the next three years through Linked Learning Detroit. Learn about Linked Learning Detroit through interviews with…

  15. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... NIDA : Facebook LinkedIn Twitter YouTube Flickr RSS Menu Home Drugs of Abuse Commonly Abused Drugs Charts Emerging ... Badges Other Resources Strategic Plan Search Share Print Home » News & Events » Public Education Projects » Learn the Link - ...

  16. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... Plan Search Share Print Home » News & Events » Public Education Projects » Learn the Link - Drugs and HIV Learn the Link - Drugs and HIV Email Facebook Twitter 2005 –Ongoing Behaviors associated with drug abuse are among the main factors in the spread of HIV infection in the ...

  17. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... Plus Facebook LinkedIn Twitter YouTube Flickr RSS Menu Home Drugs of Abuse Commonly Abused Drugs Charts Emerging ... Badges Other Resources Strategic Plan Search Share Print Home » News & Events » Public Education Projects » Learn the Link - ...

  18. Optimizing pointer linked data structures

    NARCIS (Netherlands)

    Holm, Carl Wilhelm Mattias

    2013-01-01

    The thesis explores different ways of optimizing pointer linked data structures, and especially restructuring them. The mechanisms are based on compiler technology, theory, computer languages and hardware architecture that are capable of optimizing the memory layout of complex pointer linked data st

  19. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... link between drug abuse and HIV. http://1.usa.gov/1z20ww6 How many of us think about ... can’t ignore. Learn the Link: http://1.usa.gov/1uSUAI3 Think you’re not at risk? ...

  20. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... Parents & Educators Children & Teens Search Connect with NIDA : Facebook LinkedIn Twitter YouTube Flickr RSS Menu Home Drugs ... HIV Learn the Link - Drugs and HIV Email Facebook Twitter 2005 –Ongoing Behaviors associated with drug abuse ...

  1. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... the Link campaign. This campaign shows teens and young adults that non-injection drug use and alcohol use can lead to poor decision making, which ... message to America's youth that using drugs and alcohol even once can have ... in the lives of young people-with the Learn the Link message. Campaign ...

  2. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... in your posts! Learn the link between drug abuse and HIV. http://1.usa.gov/1z20ww6 How many of us ... not at risk? Learn the link between drug abuse and HIV. http://1.usa.gov/VF4sGf [Tag friends, colleagues, partners] ...

  3. [Sex-linked juvenile retinoschisis].

    Science.gov (United States)

    François, P; Turut, P; Soltysik, C; Hache, J C

    1976-02-01

    About 13 observations of sexe linked juvenile retinoschisis, the authors describe the ophthalmoscopic, fluorographic and functional aspects of the disease whose caracteristics are:--its sexe linked recessive heredity; --its clinical characterestics associating: a microcystic macular degeneration, peripheral retinal lesions, vitreous body alterations, --an electroretinogram of the negative type.

  4. Linking Information for Mobile Use

    Science.gov (United States)

    2007-09-01

    interface after reading the XML. .. 30 Figure 8. Display of an item’s content with linked items one click away. ........... 31 Figure 9. Movement...related, but the user has not viewed recently. Figure 8. Display of an item’s content with linked items one click away. Figure 9 shows the

  5. Amsterdam Museum Linked Open Data

    NARCIS (Netherlands)

    Boer, V. de; Wielemaker, J.; Gent, J. van; O'Connell, J.; Oosterbroek, M; Hildebrand, M.; Isaac, A.; Ossenbruggen, J.R. van; Schreiber, G.

    2013-01-01

    In this document we describe the Amsterdam Museum Linked Open Data set. The dataset is a five-star Linked Data representation and comprises the entire collection of the Amsterdam Museum consisting of more than 70,000 object descriptions. Furthermore, the institution's thesaurus and person authority

  6. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... Children & Teens Search Connect with NIDA : Google Plus Facebook LinkedIn Twitter YouTube Flickr RSS Menu Home Drugs ... HIV Learn the Link - Drugs and HIV Email Facebook Twitter 2005 –Ongoing Behaviors associated with drug abuse ...

  7. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... site. Please link these banners back to this site at: http://www.drugabuse.gov/news-events/public-education-projects/learn-link-drugs-hiv . 120x90 460x80 486x60 Social Media Send the message to young people and ...

  8. Nullification of knots and links

    CERN Document Server

    Diao, Yuanan; Montemayor, Anthony

    2011-01-01

    In this paper, we study a geometric/topological measure of knots and links called the nullification number. The nullification of knots/links is believed to be biologically relevant. For example, in DNA topology, one can intuitively regard it as a way to measure how easily a knotted circular DNA can unknot itself through recombination of its DNA strands. It turns out that there are several different ways to define such a number. These definitions lead to nullification numbers that are related, but different. Our aim is to explore the mathematical properties of these nullification numbers. First, we give specific examples to show that the nullification numbers we defined are different. We provide detailed analysis of the nullification numbers for the well known 2-bridge knots and links. We also explore the relationships among the three nullification numbers, as well as their relationships with other knot invariants. Finally, we study a special class of links, namely those links whose general nullification numbe...

  9. Integrating Linked Data into Discovery

    Directory of Open Access Journals (Sweden)

    Götz Hatop

    2013-07-01

    Full Text Available Although the Linked Data paradigm has evolved from a research idea to a practical approach for publishing structured data on the web, the performance gap between currently available RDF data stores and the somewhat older search technologies could not be closed. The combination of Linked Data with a search engine can help to improve ad-hoc retrieval. This article presents and documents the process of building a search index for the Solr search engine from bibliographic records published as linked open data.

  10. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... Prevention Recovery Substance Use and SUDs in LGBT Populations Treatment Trends & Statistics Women and Drugs Publications Search ... the link between drug abuse and HIV/AIDS, populations most at risk, trends in HIV/AIDS, and ...

  11. Medicare and Medicaid Linked Files

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Medicare-Medicaid Linked Enrollee Analytic Data Source (MMLEADS) has been developed to allow for the examination of all Medicare and Medicaid enrollment and...

  12. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... affect anyone. Watch the “d’cisions” Videos Campaign Materials After the Party Posters: We have developed posters ... the Learn the Link message. Campaign messages and materials were tested among various groups of young people, ...

  13. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... Drugs and HIV Learn the Link - Drugs and HIV Email Facebook Twitter 2005 –Ongoing Behaviors associated with ... Send the Message . Get the Facts What are HIV and AIDS? HIV (human immunodeficiency virus) is the ...

  14. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available Skip to main content En español Researchers Medical & Health Professionals Patients & Families Parents & Educators Children & Teens Search Connect with NIDA : Facebook LinkedIn Twitter YouTube Flickr RSS Menu ...

  15. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... other organizations in your tweets to spread the word even further. Tweet About Learn the Link To ... other organizations in your tweets to spread the word even further. Share with Flickr, Pinterest or Instagram ...

  16. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... Researchers Medical & Health Professionals Patients & Families Parents & Educators Children & Teens Search Connect with NIDA : Facebook LinkedIn Twitter ... Network TV Organizations: AIDS.gov AIDS Alliance for Children, Youth and Families The American Academy of Child & ...

  17. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... Drugs and HIV Learn the Link - Drugs and HIV Email Facebook Twitter 2005 –Ongoing Behaviors associated with ... Send the Message . Get the Facts What are HIV and AIDS? HIV (human immunodeficiency virus) is the ...

  18. Decouplink: Dynamic Links for Java

    DEFF Research Database (Denmark)

    Jensen, Martin Lykke Rytter; Jørgensen, Bo Nørregaard

    2011-01-01

    -based systems: On the one hand, violating the open/closed principle by allowing for modification compromises independent extensibility. On the other hand, trying to enforce the open/closed principle by prohibiting modification precludes unanticipated dimensions of extension. Dynamic links increase the number...... of dimensions of extension that can be exploited without performing modification of existing types. Thus, dynamic links make it possible to enforce the open/closed principle in situations where it would otherwise not be possible. We present Decouplink – a library-based implementation of dynamic links for Java.......We also present experience with the use of dynamic links during the evolution of a component-based control system....

  19. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... NIDA’s "Learn the Link" campaign continues to raise awareness among this generation of the real risks of ... Collaborators Thanks to Those Who Have Helped Raise Awareness of Our Campaign! NIDA acknowledges the following television ...

  20. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... Military Opioid Overdose Reversal with Naloxone (Narcan, Evzio) Pain Prevention Recovery Treatment Trends & Statistics Women and Drugs ... to your Web site. Please link these banners back to this site at: http://www.drugabuse.gov/ ...

  1. Advanced solderless flexible thermal link

    Science.gov (United States)

    Williams, Brian G.; Jensen, Scott M.; Batty, J. Clair

    1996-10-01

    Flexible thermal links play an important role int he thermal management of cryogenically cooled components. The purpose of these links is to provide a means of transferring heat from a cooled component to a cooler reservoir with little increase in temperature. The standard soldered approach although effective proves to be time consuming and contributes to added thermal impedances which degrade the performance of the link. For system with little tolerance for temperature differences between cooled components and a cooling source this is undesirable. The authors of this paper have developed a technique by which thin metal foil or braided wire can be attached to metal end blocks without any solder using the swaging process. Swaging provides a fast, simple method for providing a low thermal impedance between the foils and blocks. This paper describes the characteristics of these thermal links in terms of length, mass, thermal resistance, flexibility, and survivability.

  2. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... the message to young people and to parents, teachers, and the media about the link between ... status updates that you can easily copy and paste to help show your support for ...

  3. Linking Ethics and Economic Growth

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul

    2012-01-01

    Hunt (2012) builds on his work concerning ethics and resource-advantage theory to link personal ethical standards, societal norms, and economic growth but offers few details concerning the precise mechanisms that link ethics and growth. This comment suggests a number of such mechanisms – for exam......Hunt (2012) builds on his work concerning ethics and resource-advantage theory to link personal ethical standards, societal norms, and economic growth but offers few details concerning the precise mechanisms that link ethics and growth. This comment suggests a number of such mechanisms...... – for example, the influence of prevailing ethical norms on the aggregate elasticity of substitution and, therefore, total factor productivity and growth....

  4. Study Links Disasters to Dementia

    Science.gov (United States)

    ... news/fullstory_161672.html Study Links Disasters to Dementia Losing home was tied to greater mental decline ... Earthquakes, floods and other natural disasters may raise dementia risk for seniors forced to leave their homes, ...

  5. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... affect anyone. Watch the “d’cisions” Videos Campaign Materials After the Party Posters: We have developed posters ... behaviors. NIDA researchers have studied and continue to study the links between drug abuse and HIV/AIDS. ...

  6. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... abuse and HIV infection. It contains information for young people, parents and teachers, and the media with links ... 177(1):355-361. How are Teens Affected? Young people are at risk for contracting HIV. In general, ...

  7. Protein Linked to Atopic Dermatitis

    Science.gov (United States)

    ... Research Matters NIH Research Matters January 14, 2013 Protein Linked to Atopic Dermatitis Normal skin from a ... in mice suggests that lack of a certain protein may trigger atopic dermatitis, the most common type ...

  8. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... patients who do not abuse drugs. In animal studies, methamphetamine has been shown to increase the amount ... behaviors. NIDA researchers have studied and continue to study the links between drug abuse and HIV/AIDS. ...

  9. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... Addiction Science Adolescent Brain Comorbidity College-Age & Young Adults Criminal Justice Drugged Driving Drug Testing Drugs and ... Link campaign. This campaign shows teens and young adults that non-injection drug use and alcohol use ...

  10. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... are at risk for contracting HIV. In general, middle and late teen years are when young people ... link between drug abuse and HIV. Post on Facebook or Twitter ; add photos to your Flickr , Pinterest , ...

  11. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... of HIV infection in the United States. Drugs can change the way the brain works, disrupting the ... linked and referred to as "HIV/AIDS." HIV can be transferred between people if an infected person's ...

  12. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... other organizations in your tweets to spread the word even further. Tweet About Learn the Link To ... other organizations in your tweets to spread the word even further. Share with Flickr, Pinterest or Instagram ...

  13. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... teens and young adults have never known a world without it. NIDA’s "Learn the Link" campaign continues ... NIDA TV PEERx Drugs & Health Blog The NIDA Science Fair Award for Addiction Science USA Science & Engineering ...

  14. Study Links Celiac Disease, Anorexia

    Science.gov (United States)

    ... medlineplus.gov/news/fullstory_164453.html Study Links Celiac Disease, Anorexia Chances of being diagnosed with eating ... April 4, 2017 (HealthDay News) -- Young women with celiac disease may face a heightened risk of being ...

  15. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... causes AIDS (acquired immune deficiency syndrome). AIDS is a disease of the immune system for which there ... causes (AIDS) are often linked and referred to as "HIV/AIDS." HIV can be transferred between people ...

  16. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... increasingly at risk for HIV infection through risky sexual behaviors. NIDA researchers have studied and continue to study the links between drug abuse and HIV/AIDS. In the early years of ...

  17. Intermediate links of line arrangements

    CERN Document Server

    Bodin, Arnaud

    2012-01-01

    We investigate several topological properties of line arrangements. The first result is that two generic complex line arrangements are equivalent. In fact for a line arrangement A we associate its defining polynomial f= prod_i (a_ix+b_iy+c_i), so that A = (f=0). We even prove that the defining polynomials of two generic line arrangements are topologically equivalent. In higher dimension the related result is that within a family of equivalent hyperplane arrangements the defining polynomials are topologically equivalent. A second type of objects associated to a line arrangement are links A cap S^3_r(0) obtained by intersecting the arrangement with some spheres. Several topics are discussed: (a) some link configurations can be realized by complex line arrangements but not by real line arrangements; (b) if we intersect the arrangements with a vertical band instead of a sphere, what link configurations can be obtained? (c) relations between link configurations obtained by bands and spheres.

  18. Linking DC together with TRSL

    DEFF Research Database (Denmark)

    Haxthausen, Anne Elisabeth; Yong, X.

    2000-01-01

    Duration Calculus (DC) is an interval-based real-time logic, which can be used in capturing and eliciting users' real-time requirements. The Timed RAISE Specification Language (TRSL) is an extension of the RAISE Specification Language with real-time features. This paper links DC and TRSL together...... approach for linking state-based real-time logics together with event-based, timed process algebra languages....

  19. Linked data and user interaction

    CERN Document Server

    Cervone, H Frank

    2015-01-01

    This collection of research papers provides extensive information on deploying services, concepts, and approaches for using open linked data from libraries and other cultural heritage institutions. With a special emphasis on how libraries and other cultural heritage institutions can create effective end user interfaces using open, linked data or other datasets. These papers are essential reading for any one interesting in user interface design or the semantic web.

  20. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... Link . Be sure to check out the NIDA Facebook page and tag us in your posts! Learn the link between drug abuse and HIV. http://1.usa.gov/1z20ww6 How many of us think about HIV/AIDS when we’re at parties or hanging out with friends? It’s a topic you can’t ignore. Learn ...

  1. Linking Ethics and Economic Growth

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul

    2012-01-01

    Hunt (2012) builds on his work concerning ethics and resource-advantage theory to link personal ethical standards, societal norms, and economic growth but offers few details concerning the precise mechanisms that link ethics and growth. This comment suggests a number of such mechanisms...... – for example, the influence of prevailing ethical norms on the aggregate elasticity of substitution and, therefore, total factor productivity and growth....

  2. LinkMind: link optimization in swarming mobile sensor networks.

    Science.gov (United States)

    Ngo, Trung Dung

    2011-01-01

    A swarming mobile sensor network is comprised of a swarm of wirelessly connected mobile robots equipped with various sensors. Such a network can be applied in an uncertain environment for services such as cooperative navigation and exploration, object identification and information gathering. One of the most advantageous properties of the swarming wireless sensor network is that mobile nodes can work cooperatively to organize an ad-hoc network and optimize the network link capacity to maximize the transmission of gathered data from a source to a target. This paper describes a new method of link optimization of swarming mobile sensor networks. The new method is based on combination of the artificial potential force guaranteeing connectivities of the mobile sensor nodes and the max-flow min-cut theorem of graph theory ensuring optimization of the network link capacity. The developed algorithm is demonstrated and evaluated in simulation.

  3. LinkMind: Link Optimization in Swarming Mobile Sensor Networks

    Directory of Open Access Journals (Sweden)

    Trung Dung Ngo

    2011-08-01

    Full Text Available A swarming mobile sensor network is comprised of a swarm of wirelessly connected mobile robots equipped with various sensors. Such a network can be applied in an uncertain environment for services such as cooperative navigation and exploration, object identification and information gathering. One of the most advantageous properties of the swarming wireless sensor network is that mobile nodes can work cooperatively to organize an ad-hoc network and optimize the network link capacity to maximize the transmission of gathered data from a source to a target. This paper describes a new method of link optimization of swarming mobile sensor networks. The new method is based on combination of the artificial potential force guaranteeing connectivities of the mobile sensor nodes and the max-flow min-cut theorem of graph theory ensuring optimization of the network link capacity. The developed algorithm is demonstrated and evaluated in simulation.

  4. Seismic link at plate boundary

    Indian Academy of Sciences (India)

    Faical Ramdani; Omar Kettani; Benaissa Tadili

    2015-06-01

    Seismic triggering at plate boundaries has a very complex nature that includes seismic events at varying distances. The spatial orientation of triggering cannot be reduced to sequences from the main shocks. Seismic waves propagate at all times in all directions, particularly in highly active zones. No direct evidence can be obtained regarding which earthquakes trigger the shocks. The first approach is to determine the potential linked zones where triggering may occur. The second step is to determine the causality between the events and their triggered shocks. The spatial orientation of the links between events is established from pre-ordered networks and the adapted dependence of the spatio-temporal occurrence of earthquakes. Based on a coefficient of synchronous seismic activity to grid couples, we derive a network link by each threshold. The links of high thresholds are tested using the coherence of time series to determine the causality and related orientation. The resulting link orientations at the plate boundary conditions indicate that causal triggering seems to be localized along a major fault, as a stress transfer between two major faults, and parallel to the geothermal area extension.

  5. Links

    OpenAIRE

    Alessandra Russo

    2006-01-01

    La lista de enlaces ofrecida a continuación tiene como objetivo la creación de una base de datos sobre los principales sitios de interés para el estudio de la imagen (en America Latina y más allá). Se ha tratado de incluir una vasta gama de instituciones (museos, colecciones, institutos), representando sin embargo también a revistas, proyectos de investigación, y catálogos en línea. Sin tener la pretensión de ser exhaustiva, esta selección es evolutiva y se pone al día continuamente. MuseosI...

  6. Links

    Directory of Open Access Journals (Sweden)

    Alessandra Russo

    2006-02-01

    Full Text Available La lista de enlaces ofrecida a continuación tiene como objetivo la creación de una base de datos sobre los principales sitios de interés para el estudio de la imagen (en America Latina y más allá. Se ha tratado de incluir una vasta gama de instituciones (museos, colecciones, institutos, representando sin embargo también a revistas, proyectos de investigación, y catálogos en línea. Sin tener la pretensión de ser exhaustiva, esta selección es evolutiva y se pone al día continuamente. MuseosI...

  7. On ω-Linked Overrings

    Institute of Scientific and Technical Information of China (English)

    Lin XIE; Fang Gui WANG; Yan TIAN

    2011-01-01

    Let R (C) T be an extension of commutative rings. T is called ω-linked over R if T as an R-module is a ω-module. In the case of R (C) T (C) Q0(R), T is called a ω-linked overring of R. As a generalization of Wang-McCsland-Park-Chang Theorem, we show that if R is a reduced ring, then R is a ω-Noetherian ring with ω-dim(R) ≤1 if and only if each ω-linked overring T of R is a ω-Noetherian ring with ω-dim(T) ≤ 1. In particular, R is a ω-Noetherian ring with ω-dim(R) = 0 if and only if R is an Artinian ring.

  8. Deformation of Linked Polymer Coils

    Institute of Scientific and Technical Information of China (English)

    董朝霞; 李明远; 吴肇亮; 林梅钦

    2003-01-01

    Linked polymer solution (LPS) is defined as the solution of linked polymer coils (LPCs) dispersed in water, composed of low concentration partially hydrolyzed polyacrylamide (HPAM) and aluminum citrate (crosslinker). In the work, the conformational changes of LPCs under different conditions were investigated by the methods of membrane filtering under low pressure, dynamic light scattering and core flooding experiments. The results showed that in some conditions the LPCs could be compressed mechanically to 1/158.5 of their original volume because of relatively lower HPAM cross-linking. The hydration property of LPCs was similar to that of normal polymer coils. The deformation of LPCs was more restricted than that of ordinary polymer coils under the flow shear stress or the shift of hydration equilibrium caused in the variation of the electrolyte concentration which is responsible for the effective plugging in the throats of porous media when LPCs are used for deep diverting.

  9. Link Prediction via Matrix Completion

    CERN Document Server

    Pech, Ratha; Pan, Liming; Cheng, Hong; Zhou, Tao

    2016-01-01

    Inspired by practical importance of social networks, economic networks, biological networks and so on, studies on large and complex networks have attracted a surge of attentions in the recent years. Link prediction is a fundamental issue to understand the mechanisms by which new links are added to the networks. We introduce the method of robust principal component analysis (robust PCA) into link prediction, and estimate the missing entries of the adjacency matrix. On one hand, our algorithm is based on the sparsity and low rank property of the matrix, on the other hand, it also performs very well when the network is dense. This is because a relatively dense real network is also sparse in comparison to the complete graph. According to extensive experiments on real networks from disparate fields, when the target network is connected and sufficiently dense, whatever it is weighted or unweighted, our method is demonstrated to be very effective and with prediction accuracy being considerably improved comparing wit...

  10. The OceanLink Project

    Science.gov (United States)

    Narock, T.; Arko, R. A.; Carbotte, S. M.; Chandler, C. L.; Cheatham, M.; Finin, T.; Hitzler, P.; Krisnadhi, A.; Raymond, L. M.; Shepherd, A.; Wiebe, P. H.

    2014-12-01

    A wide spectrum of maturing methods and tools, collectively characterized as the Semantic Web, is helping to vastly improve the dissemination of scientific research. Creating semantic integration requires input from both domain and cyberinfrastructure scientists. OceanLink, an NSF EarthCube Building Block, is demonstrating semantic technologies through the integration of geoscience data repositories, library holdings, conference abstracts, and funded research awards. Meeting project objectives involves applying semantic technologies to support data representation, discovery, sharing and integration. Our semantic cyberinfrastructure components include ontology design patterns, Linked Data collections, semantic provenance, and associated services to enhance data and knowledge discovery, interoperation, and integration. We discuss how these components are integrated, the continued automated and semi-automated creation of semantic metadata, and techniques we have developed to integrate ontologies, link resources, and preserve provenance and attribution.

  11. When He Said Linking, He Really Meant Linking

    Science.gov (United States)

    Chudnov, Daniel

    2009-01-01

    There are many reasons to improve web links, starting with their design. The author tends to think about "design" on the web in terms of two things: (1) graphic/industrial design; and (2) human usability. A nice, clean URI (uniform resource identifier) that does not change, is readable to humans, is amenable to common web behaviors such as…

  12. LinkMind: Link Optimization in Swarming Mobile Sensor Networks

    DEFF Research Database (Denmark)

    Ngo, Trung Dung

    2012-01-01

    optimization of swarming mobile sensor networks. The new method is based on combination of the artificial potential force guaranteeing connectivities of the mobile sensor nodes and the max-flow min-cut theorem of graph theory ensuring optimization of the network link capacity. The developed algorithm...

  13. Versatile Link PLUS transceiver development

    Science.gov (United States)

    Soós, C.; Détraz, S.; Olanterä, L.; Sigaud, C.; Troska, J.; Vasey, F.; Zeiler, M.

    2017-03-01

    The Versatile Link PLUS project targets the phase II upgrades of the ATLAS and CMS experiments. It will develop a radiation resistant optical link, operating at up to 10 Gb/s in the upstream and up to 5 Gb/s in the downstream directions with a smaller footprint and higher channel count than its predecessor. A low-profile package is being developed that allows volume production at reduced costs, but which nevertheless can be configured to suit the individual channel count needs of different detectors. This paper describes the development strategies and summarizes the status of the feasibility demonstration phase of the project.

  14. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... Badges Other Resources Strategic Plan Search Share Print Home » News & Events » Public Education Projects » Learn the Link - Drugs and HIV Learn ... Montgomery College Center for the Advancement of Distance Education University of ... Companies: Washington Metropolitan Area Transit Authority (WMATA) Dallas Area ...

  15. What is Linked Historical Data?

    NARCIS (Netherlands)

    Meroño-Peñuela, A.; Hoekstra, R.

    2014-01-01

    Datasets that represent historical sources are relative newcomers in the Linked Open Data (LOD) cloud. Following the standard LOD practices for publishing historical sources raises several questions: how can we distinguish between RDF graphs of primary and secondary sources? Should we treat archived

  16. What Is Linked Historical Data?

    NARCIS (Netherlands)

    Meroño-Peñuela, Albert; Hoekstra, Rinke; Janowicz, Krzysztof; Schlobach, Stefan; Lambrix, Patrick; Hyvönen, Eero

    2014-01-01

    Datasets that represent historical sources are relative new- comers in the Linked Open Data (LOD) cloud. Following the standard LOD practices for publishing historical sources raises several questions: how can we distinguish between RDF graphs of primary and secondary sources? Should we treat

  17. The intersubjective links in perversion.

    Science.gov (United States)

    Eiguer, Alberto

    2007-10-01

    The author studies the intersubjective links which the pervert maintains with analyst or partner, attempting to indicate the differences between the investments in each case. Rather than accepting that empathy towards these patients is impossible to achieve and disturbs the countertransference profoundly, it attempts to show that these difficulties may be overcome if they are reinterpreted in the light of the theory of the intersubjective link. The author examines the theories and the practice of intersubjectivity and gives a definition of his approach to the link between two subjects. He applies these ideas to the case of a sexually masochistic female patient. The countertransference is marked successively by indifference, rejection and smothering. The analysis of the analyst's dream allows the situation to evolve. Failures in primary identification can result in domination over others and utilitarianism. The author examines the place of the challenge to the 'Law' and the father (in the attempt by the patient to put a theory to the test) in order to identify the figure of the witness in the pervert's intersubjective links. The desire of the transference would be marked by the figure of the witness rather than by that of the analyst as accomplice.

  18. Property Testing on Linked Lists

    DEFF Research Database (Denmark)

    Afshani, Peyman; Matulef, Kevin; Wilkinson, Bryan Thomas

    2013-01-01

    We define a new property testing model for algorithms that do not have arbitrary query access to the input, but must instead traverse it in a manner that respects the underlying data structure in which it is stored. In particular, we consider the case when the underlying data structure is a linked...

  19. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... CDC, DHHS. Retrieved June 2012 How are Drug Abuse and HIV Related? Drug abuse and addiction have been linked with HIV/AIDS ... this regard, the role that non-injection drug abuse plays in the spread of HIV is less ...

  20. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... for contracting or transmitting HIV/AIDS or other infectious diseases. Research Reports: HIV/AIDS : Explores the link between ... Network TV Organizations: AIDS.gov AIDS Alliance for Children, Youth and Families The American Academy of Child & ...

  1. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... judgment and risky behavior. Drug abuse by any route (not just injection) can put a person at ... http://www.drugabuse.gov/news-events/public-education-projects/learn-link-drugs-hiv . 120x90 460x80 486x60 Social ...

  2. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... projects/learn-link-drugs-hiv . 120x90 460x80 486x60 Social Media Send the message to young people and ... Health Blog The NIDA Science Fair Award for Addiction Science USA Science & Engineering Festival Drug & Alcohol Chat ...

  3. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... projects/learn-link-drugs-hiv . 120x90 460x80 486x60 Social Media Send the message to young people and ... available for your use to share on your social media accounts. About the Campaign Overview The Learn ...

  4. Linking aboveground and belowground diversity

    NARCIS (Netherlands)

    Deyn, de G.B.; Putten, van der W.H.

    2005-01-01

    Aboveground and belowground species interactions drive ecosystem properties at the local scale, but it is unclear how these relationships scale-up to regional and global scales. Here, we discuss our current knowledge of aboveground and belowground diversity links from a global to a local scale. Glob

  5. Tweaking Synchronisation by Link Addition

    CERN Document Server

    Schultz, Paul; Eroglu, Deniz; Stemler, Thomas; Ávila, G Marcelo Ramírez; Rodrigues, Francisco A; Kurths, Jürgen

    2016-01-01

    Natural and man-made networks often possess locally tree-like sub-structures. Taking such tree networks as our starting point, we show how the addition of links changes the synchronization properties of the network. We focus on two different methods of link addition. The first method adds single links that create cycles of a well-defined length. Following a topological approach we introduce cycles of varying length and analyze how this feature, as well as the position in the network, alters the synchronous behaviour. We show that in particular short cycles can lead to a maximum change of the Laplacian's eigenvalue spectrum, dictating the synchronization properties of such networks. The second method connects a certain proportion of the initially unconnected nodes. We simulate dynamical systems on these network topologies, with the nodes' local dynamics being either a discrete or continuous. Here our main result is that a certain amount of additional links, with the relative position in the network being cruci...

  6. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... the News NIDA Notes Podcasts E-Newsletters Public Education Projects Contact the Press Office Meetings & Events Media ... Plan Search Share Print Home » News & Events » Public Education Projects » Learn the Link - Drugs and HIV Learn ...

  7. What is Linked Historical Data?

    NARCIS (Netherlands)

    Meroño-Peñuela, A.; Hoekstra, R.

    2014-01-01

    Datasets that represent historical sources are relative newcomers in the Linked Open Data (LOD) cloud. Following the standard LOD practices for publishing historical sources raises several questions: how can we distinguish between RDF graphs of primary and secondary sources? Should we treat archived

  8. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... Send the Message . Get the Facts What are HIV and AIDS? HIV (human immunodeficiency virus) is the virus that ... AIDS) are often linked and referred to as "HIV/AIDS." HIV can be transferred between people if an ...

  9. Is Wikipedia link structure different?

    NARCIS (Netherlands)

    Kamps, J.; Koolen, M.; Baeza-Yates, R.; Boldi, P.; Ribeiro-Neto, B.; Cambazoglu, B.B.

    2010-01-01

    In this paper, we investigate the difference between Wikipedia and Web link structure with respect to their value as indicators of the relevance of a page for a given topic of request. Our experimental evidence is from two IR test-collections: the .GOV collection used at the TREC Web tracks and the

  10. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... in the lives of young people-with the Learn the Link message. Campaign messages and materials were tested among various groups of young people, guiding the use of technology, the discussion between friends, and the importance of family. For more information, read a message ...

  11. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... projects/learn-link-drugs-hiv . 120x90 460x80 486x60 Social Media Send the message to young people and to ... available for your use to share on your social media accounts. About the Campaign Overview The Learn the ...

  12. Current Leads, Links and Buses

    CERN Document Server

    Ballarino, A

    2014-01-01

    Electrical transfer from a room temperature power source to a superconducting system is done via conventional or superconducting current leads and superconducting buses or links. The principles of optimization of these devices are presented, with emphasis on the cryogenic, electrical, and superconductor related aspects that drive choices for a system.

  13. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... HIV > Learn the Link campaign. This campaign shows teens and young adults that non-injection drug use and alcohol use can lead to poor decision making, which can result in risky sexual behaviors and HIV infection. Although the characters are fictional, ...

  14. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... learn-link-drugs-hiv . 120x90 460x80 486x60 Social Media Send the message to young people and to ... clear that injection drug abuse played a significant role in the widespread transmission of the disease. Since ...

  15. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available Skip to main content En español Researchers Medical & Health Professionals Patients & Families Parents & Educators Children & Teens Search Connect with NIDA : Facebook LinkedIn Twitter YouTube Flickr RSS Menu Home Drugs of Abuse ...

  16. What Is Linked Historical Data?

    NARCIS (Netherlands)

    Meroño-Peñuela, Albert; Hoekstra, Rinke; Janowicz, Krzysztof; Schlobach, Stefan; Lambrix, Patrick; Hyvönen, Eero

    2014-01-01

    Datasets that represent historical sources are relative new- comers in the Linked Open Data (LOD) cloud. Following the standard LOD practices for publishing historical sources raises several questions: how can we distinguish between RDF graphs of primary and secondary sources? Should we treat archiv

  17. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... HIV/AIDS, and the general public. U.S. National Library of Medicine HIV/AIDS Information : Specialized Information Services. ... link between drug abuse and HIV. Post on Facebook or Twitter ; add photos to your Flickr , Pinterest , ...

  18. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... with HIV is a key predictor of the development of AIDS. Because of their compromised immune system, ... at: http://www.drugabuse.gov/news-events/public-education-projects/learn-link-drugs-hiv . 120x90 460x80 486x60 ...

  19. Reconceptualizing the Linked Courses Model

    Science.gov (United States)

    Baxter, Mary

    2008-01-01

    To help students meet the demands of society, the University of Houston is using the framework of learning communities and constructivism to create a cross-disciplinary approach to teaching to provide media-rich thematically linked courses to engage a diverse student population. A case study investigated three semesters of thematically linked…

  20. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... projects/learn-link-drugs-hiv . 120x90 460x80 486x60 Social Media Send the message to young people and to ... available for your use to share on your social media accounts. About the Campaign Overview The Learn the ...

  1. LCSH, SKOS and Linked Data

    CERN Document Server

    Summers, Ed; Redding, Clay; Krech, Dan

    2008-01-01

    A technique for converting Library of Congress Subject Headings MARCXML to Simple Knowledge Organization System (SKOS) RDF is described. Strengths of the SKOS vocabulary are highlighted, as well as possible points for extension, and the integration of other semantic web vocabularies such as Dublin Core. An application for making the vocabulary available as linked-data on the Web is also described.

  2. New links in the family

    NARCIS (Netherlands)

    Marion Duimel; Jos de Haan

    2007-01-01

    Original title: Nieuwe links in het gezin. Virtually all families with teenagers have at least one computer with an Internet connection, often more. Teenagers spend much of their daily lives on the Internet. They use it to communicate with each other, to do their schoolwork, to meet new friends and

  3. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... Since the late 1980s, research has shown that treating drug abuse is an effective way to prevent the spread ... increasingly at risk for HIV infection through risky sexual behaviors. NIDA researchers have studied and continue to study the links between drug abuse and HIV/AIDS. In the early years of ...

  4. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... Tobacco/Nicotine and E-Cigs Other Drugs Related Topics Addiction Science Adolescent Brain Comorbidity College-Age & Young ... parties or hanging out with friends? It’s a topic you can’t ignore. Learn the Link: http:// ...

  5. Drugs + HIV, Learn the Link

    Medline Plus

    Full Text Available ... the News NIDA Notes Podcasts E-Newsletters Public Education Projects Contact the Press Office Meetings & Events Media ... Plan Search Share Print Home » News & Events » Public Education Projects » Learn the Link - Drugs and HIV Learn ...

  6. Architecture of Platonic and Archimedean polyhedral links

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A new methodology for understanding the construction of polyhedral links has been developed on the basis of the Platonic and Archimedean solids by using our method of the 'three-cross-curve and doubletwist-line covering'. There are five classes of polyhedral links that can be explored: the tetrahedral and truncated tetrahedral links; the hexahedral and truncated hexahedral links; the dodecahedral and truncated dodecahedral links; the truncated octahedral and icosahedral links. Our results show that the tetrahedral and truncated tetrahedral links have T symmetry; the hexahedral and truncated hexahedral links, as well as the truncated octahedral links, O symmetry; the dodecahedral and truncated dodecahedral links, as well as the truncated icosahedral links, I symmetry, respectively. This study provides further insight into the molecular design, as well as theoretical characterization, of the DNA and protein catenanes.

  7. Architecture of Platonic and Archimedean polyhedral links

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A new methodology for understanding the construction of polyhedral links has been developed on the basis of the Platonic and Archimedean solids by using our method of the ‘three-cross-curve and dou- ble-twist-line covering’. There are five classes of polyhedral links that can be explored: the tetrahedral and truncated tetrahedral links; the hexahedral and truncated hexahedral links; the dodecahedral and truncated dodecahedral links; the truncated octahedral and icosahedral links. Our results show that the tetrahedral and truncated tetrahedral links have T symmetry; the hexahedral and truncated hexahedral links, as well as the truncated octahedral links, O symmetry; the dodecahedral and truncated dodeca- hedral links, as well as the truncated icosahedral links, I symmetry, respectively. This study provides further insight into the molecular design, as well as theoretical characterization, of the DNA and protein catenanes.

  8. Flexible isotopy classification of flexible links

    OpenAIRE

    Björklund, Johan

    2012-01-01

    In this paper we define and study flexible links and flexible isotopy in projective space. Flexible links are meant to capture the topological properties of real algebraic links. We classify all flexible links up to flexible isotopy using Ekholms interpretation of Viros encomplexed writhe.

  9. The importance of link evidence in Wikipedia

    NARCIS (Netherlands)

    Kamps, J.; Koolen, M.

    2008-01-01

    Wikipedia is one of the most popular information sources on the Web. The free encyclopedia is densely linked. The link structure in Wikipedia differs from the Web at large: internal links in Wikipedia are typically based on words naturally occurring in a page, and link to another semantically relate

  10. Propensity to Click on Suspicious Links

    DEFF Research Database (Denmark)

    Sudzina, Frantisek; Pavlicek, Antonin

    2017-01-01

    There already exists a certain, not huge, body of knowledge about impact of personality traits on susceptibility to phishing. But there is a gap when it comes specifically to phishing with links pretending to lead to deal sites. The paper analyzes if gender, age and personality traits influence.......1. Openness to experience was linked positively linked to responsible behavior, narcissism was negatively linked....

  11. X-linked Alport syndrome

    DEFF Research Database (Denmark)

    Jais, Jean Philippe; Knebelmann, Bertrand; Giatras, Iannis

    2003-01-01

    Alport syndrome (AS) is a type IV collagen hereditary disease characterized by progressive hematuric nephritis, hearing loss, and ocular changes. Mutations in the COL4A5 collagen gene are responsible for the more common X-linked dominant form of the disease characterized by much less severe disease...... defects developed in 75%, 28%, and 15%, respectively. The probability of developing end-stage renal disease or deafness before the age of 40 yr was 12% and 10%, respectively, in girls and women versus 90 and 80%, respectively, in boys and men. The risk of progression to end-stage renal disease appears...... to increase after the age of 60 yr in women. Because of the absence of genotype-phenotype correlation and the large intrafamilial phenotypic heterogeneity, early prognosis of the disease in X-linked Alport syndrome carriers remains moot. Risk factors for developing renal failure have been identified...

  12. X-linked Alport syndrome

    DEFF Research Database (Denmark)

    Jais, Jean Philippe; Knebelmann, Bertrand; Giatras, Iannis

    2003-01-01

    Alport syndrome (AS) is a type IV collagen hereditary disease characterized by progressive hematuric nephritis, hearing loss, and ocular changes. Mutations in the COL4A5 collagen gene are responsible for the more common X-linked dominant form of the disease characterized by much less severe disease...... in girls and women. A "European Community Alport Syndrome Concerted Action" (ECASCA) group was established to delineate the Alport syndrome phenotype in each gender and to determine genotype-phenotype correlations in a large number of families. Data concerning 329 families, 250 of them with an X...... to increase after the age of 60 yr in women. Because of the absence of genotype-phenotype correlation and the large intrafamilial phenotypic heterogeneity, early prognosis of the disease in X-linked Alport syndrome carriers remains moot. Risk factors for developing renal failure have been identified...

  13. Collagen cross linking: Current perspectives

    Directory of Open Access Journals (Sweden)

    Srinivas K Rao

    2013-01-01

    Full Text Available Keratoconus is a common ectatic disorder occurring in more than 1 in 1,000 individuals. The condition typically starts in adolescence and early adulthood. It is a disease with an uncertain cause and its progression is unpredictable, but in extreme cases, vision deteriorates and can require corneal transplant surgery. Corneal collagen cross-linking (CCL with riboflavin (C3R is a recent treatment option that can enhance the rigidity of the cornea and prevent disease progression. Since its inception, the procedure has evolved with newer instrumentation, surgical techniques, and is also now performed for expanded indications other than keratoconus. With increasing experience, newer guidelines regarding optimization of patient selection, the spectrum of complications and their management, and combination procedures are being described. This article in conjunction with the others in this issue, will try and explore the uses of collagen cross-linking (CXL in its current form.

  14. The Øresund Link

    DEFF Research Database (Denmark)

    Møller, Jacob Steen

    of hydrodynamic modelling, on line monitoring and access to all environmental information through a GIS based information system. The public attitude towards the project in general and the environmental impact in particular shifted from a very sceptical one at the beginning of the project to a very positive one......-km link across the Sound could potentially impact the water exchange between the Baltic Sea and the North Sea, and the dredging activities during construction were a threat to the local marine environment. The public interest in the environmental issues together with a pro-active environmental policy...... towards the completion of the link. It is believed that the careful use of new technology both for environmental prediction and for public information has played a major role in this development....

  15. Using turbocodes on optical links

    Directory of Open Access Journals (Sweden)

    Glenn Claes

    2006-04-01

    Full Text Available The fast evolving telecommunication world is permanently in search for faster and better communication links. On one hand, turbo codes are like a dream come true. Due to their amazing performance, they have become the reference in the word of error detecting and correcting codes. On the other hand, broadband transmission channels like optical fibres can meet the need for higher transmission velocity. In this paper therefore we will bring these two elements together and thus the performance of turbocodes on optical links will be studied. First the turbocode will be optimised throughout an individual analysis of each of its design parameters. Moreover it wil be shown that turbocodes have much better performance than the well known Reed-Solomon codes. Finally we will show that the 8Bit/10Bit code, which is required to comply with the Gigabit Ethernet standard, becomes superfluous when working with turbocodes. All tests were carried out on multimode graded-index glass fibres.

  16. X-linked Alport syndrome

    DEFF Research Database (Denmark)

    Jais, J P; Knebelmann, B; Giatras, I

    2000-01-01

    Alport syndrome (AS) is a type IV collagen hereditary disease characterized by the association of progressive hematuric nephritis, hearing loss, and, frequently, ocular changes. Mutations in the COL4A5 collagen gene are responsible for the more common X-linked dominant form of the disease....... Considerable allelic heterogeneity has been observed. A "European Community Alport Syndrome Concerted Action" has been established to delineate accurately the AS phenotype and to determine genotype-phenotype correlations in a large number of families. Data concerning 329 families, 250 of them with an X...... of age was approximately 60% in patients with missense mutations, contrary to 90% for the other types of mutations. The natural history of X-linked AS and correlations with COL4A5 mutations have been established in a large cohort of male patients. These data could be used for further evaluation...

  17. Linking nutrition-health-agriculture

    OpenAIRE

    2013-01-01

    Agricultural production is intimately linked with health and nutrition as a form of income, a source of food, and a cause of disease. Citing a variety of previous studies, this presentation demonstrates the complexity of the relationships among agriculture and food consumption, food safety, infection, and stunting. The authors demonstrate that increasing agricultural production does not necessarily result in improved nutrition: Although more food may be available, this greater yield may suppl...

  18. How expensive is link utilization?

    OpenAIRE

    Stanojević, Rade; Shorten, Robert

    2007-01-01

    Understanding the relationship between queueing delays and link utilization for general traffic conditions is an important open problem in networking research. Difficulties in understanding this relationship stem from the fact that it depends on the complex nature of arriving traffic and the problems associated with modelling such traffic. Existing AQM schemes achieve a "low delay" and "high utilization" by responding early to congestion without considering the exact relationship betwee...

  19. Managing Your Team's Weakest Link.

    Science.gov (United States)

    Hills, Laura

    2015-01-01

    Do you have a poor-performing employee on your medical practice team? If so, you're not alone. Unfortunately, this is a problem that many medical practice managers face. This article describes the best strategies for managing your team's weakest link. It explores common yet very difficult circumstances that cause low employee performance and that test the patience, heart, and skills of a practice manager. It guides readers through a process of self-discovery to determine whether their negative biases or grudges may be causing employees to perform poorly. It suggests several possible other reasons for weak employee performance, including problems with the job, practice, leadership, communication, and fit between the employee and the job. This article also suggests the best strategy for communicating concerns about performance to the weakest-link employee. It offers guidance to practice managers about protecting their time and energy when handling a poor performer. It provides a simple formula for calculating the cost of a low-performing employee, 10 possible personal reasons for the employee's poor work performance, specific questions to ask to uncover the reasons for poor performance, and an eight-rule strategy for confronting poor performance effectively. Finally, this article offers practice managers a practical strategy for handling resistance from their weakest link, illustrated with a sample dialogue.

  20. The Øresund Link

    DEFF Research Database (Denmark)

    Møller, Jacob Steen

    "Øresundsbron" is the combined bridge and tunnel connecting Denmark and Sweden adjacent to Copenhagen. Øresundsbron was built and is operated by a consortium owned jointly by the Danish and Swedish states. The Link was inaugurated 1 July 2000 by the Queen of Denmark and the King of Sweden. The 16...... towards the completion of the link. It is believed that the careful use of new technology both for environmental prediction and for public information has played a major role in this development.......-km link across the Sound could potentially impact the water exchange between the Baltic Sea and the North Sea, and the dredging activities during construction were a threat to the local marine environment. The public interest in the environmental issues together with a pro-active environmental policy...... of hydrodynamic modelling, on line monitoring and access to all environmental information through a GIS based information system. The public attitude towards the project in general and the environmental impact in particular shifted from a very sceptical one at the beginning of the project to a very positive one...

  1. Linking GHG Emission Trading Systems and Markets

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    Several different types of links are possible between different GHG-mitigation systems. These include: Linking two or more emission trading schemes so that emissions trading can occur both within and between different schemes ('direct links'); and Linking emission trading systems to registries/mechanisms and systems that generate offsets from project based mechanisms or from direct purchases/transfers of AAUs ('indirect links').

  2. Linking DC together with TRSL

    DEFF Research Database (Denmark)

    Haxthausen, Anne; Yong, Xia

    1999-01-01

    of constraints on the durations of states of the system, i.e. at a high level of abstraction.However, as a state-based logic, it lacks the ability to specifysequential programs and communicating concurrent processes at a concrete level. The Timed RAISE Specification Language (TRSL) [XG99] has this ability...... (parts of) the history of the observables of the system,and then define a satisfaction relation in terms of behaviours. DC has previously been linked together with subsets of other event-based process algebra languages, but using another approach:the event-based languages were given a denotational...

  3. Zika Linked to Deformed Limbs in Newborns

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_160324.html Zika Linked to Deformed Limbs in Newborns Cause isn' ... 2016 TUESDAY, Aug. 9, 2016 (HealthDay News) -- The Zika virus has already been linked to serious birth ...

  4. Study Links Psychiatric Disorders to Stroke Risk

    Science.gov (United States)

    ... fullstory_163750.html Study Links Psychiatric Disorders to Stroke Risk Mental health woes may trigger chronic fight- ... may be linked to a higher risk of stroke in the following weeks and months, new research ...

  5. X-linked genes and mental functioning

    National Research Council Canada - National Science Library

    Skuse, David H

    2005-01-01

    ... (as indicated by the large number of X-linked mental retardation syndromes). In addition, there is evidence for relatively specific effects of X-linked genes on social-cognition and emotional regulation...

  6. Researchers Pinpoint More Genes Linked to Vitiligo

    Science.gov (United States)

    ... 161452.html Researchers Pinpoint More Genes Linked to Vitiligo Genetic clues to this autoimmune disease could lead ... identified more genes linked to the autoimmune disease vitiligo, which causes patches of white skin and hair. ...

  7. Seizures and X-linked intellectual disability

    OpenAIRE

    Stevenson, Roger E; Holden, Kenton R.; Rogers, R. Curtis; Schwartz, Charles E.

    2012-01-01

    Intellectual disability occurs as an isolated X-linked trait and as a component of recognizable X-linked syndromes in the company of somatic, metabolic, neuromuscular, or behavioral abnormalities. Seizures accompany intellectual disability in almost half of these X-linked disorders. The spectrum of seizures found in the X-linked intellectual disability syndromes is broad, varying in time of onset, type of seizure, and response to anticonvulsant therapy. The majority of the genes associated wi...

  8. Track with overlapping links for dry coal extrusion pumps

    Science.gov (United States)

    Saunders, Timothy; Brady, John D

    2014-01-21

    A chain for a particulate material extrusion pump includes a plurality of links, each of the plurality of links having a link body and a link ledge, wherein each link ledge of the plurality of links at least partially overlaps the link body of an adjacent one of the plurality of links.

  9. Production and Consumption of University Linked Data

    Science.gov (United States)

    Zablith, Fouad; Fernandez, Miriam; Rowe, Matthew

    2015-01-01

    Linked Data increases the value of an organisation's data over the web by introducing explicit and machine processable links at the data level. We have adopted this new stream of data representation to produce and expose existing data within The Open University (OU) as Linked Data. We present in this paper our approach for producing the data,…

  10. Electrospinning formaldehyde cross-linked zein solutions

    Science.gov (United States)

    In order to develop zein fibers with improved physical properties and solvent resistance, formaldehyde was used as the cross-linking reagent before spinning. The cross-linking reaction was carried out in either acetic acid or ethanolic-HCl where the amount of cross-linking reagent was between 1 and...

  11. X-linked Alport syndrome

    DEFF Research Database (Denmark)

    Jais, J P; Knebelmann, B; Giatras, I

    2000-01-01

    . Considerable allelic heterogeneity has been observed. A "European Community Alport Syndrome Concerted Action" has been established to delineate accurately the AS phenotype and to determine genotype-phenotype correlations in a large number of families. Data concerning 329 families, 250 of them with an X......-linked transmission, were collected. Characteristics of the 401 male patients belonging to the 195 families with COL4A5 mutation are presented. All male patients were hematuric, and the rate of progression to end-stage renal failure and deafness was mutation-dependent. Large deletions, non-sense mutations, or small...... mutations changing the reading frame conferred to affected male patients a 90% probability of developing end-stage renal failure before 30 yr of age, whereas the same risk was of 50 and 70%, respectively, in patients with missense or splice site mutation. The risk of developing hearing loss before 30 yr...

  12. PIPELINES AS COMMUNICATION NETWORK LINKS

    Energy Technology Data Exchange (ETDEWEB)

    Kelvin T. Erickson; Ann Miller; E. Keith Stanek; C.H. Wu; Shari Dunn-Norman

    2005-03-14

    This report presents the results of an investigation into two methods of using the natural gas pipeline as a communication medium. The work addressed the need to develop secure system monitoring and control techniques between the field and control centers and to robotic devices in the pipeline. In the first method, the pipeline was treated as a microwave waveguide. In the second method, the pipe was treated as a leaky feeder or a multi-ground neutral and the signal was directly injected onto the metal pipe. These methods were tested on existing pipeline loops at UMR and Batelle. The results reported in this report indicate the feasibility of both methods. In addition, a few suitable communication link protocols for this network were analyzed.

  13. Linking Customer Interaction and Innovation

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul; Laursen, Keld; Pedersen, Torben

    2011-01-01

    The notion that firms can improve their innovativeness by tapping users and customers for knowledge has become prominent in innovation studies. Similar arguments have been made in the marketing literature. We argue that neither literatures take sufficient account of firm organization. Specifically......, firms that attempt to leverage user and customer knowledge in the context of innovation must design an internal organization appropriate to support it. This can be achieved in particular through the use of new organizational practices, notably, intensive vertical and lateral communication, rewarding...... employees for sharing and acquiring knowledge, and high levels of delegation of decision rights. In this paper, six hypotheses were developed and tested on a data set of 169 Danish firms drawn from a 2001 survey of the 1,000 largest firms in Denmark. A key result is that the link from customer knowledge...

  14. X-linked congenital retinoschisis.

    Science.gov (United States)

    Kellner, U; Brümmer, S; Foerster, M H; Wessing, A

    1990-01-01

    The natural history and electrophysiological findings of 52 patients with X-linked congenital retinoschisis with a follow-up of up to 26 years are described. The mean visual acuity was reduced to 0.24 +/- 0.2 and remained unchanged in most patients during this time. If visual loss occurred, it usually happened in the first decennium. The complications were retinal detachments in 11% and vitreous hemorrhages in 4% of the eyes. In general, the vitreous hemorrhages resolved spontaneously. Retinal detachments were treated successfully with conventional buckling procedures. Redetachments occurred in about 40%. Prophylactic laser coagulation was of no use because it was complicated by detachment in 43% of our series. The electro-oculogram was usually normal. In addition to the known electrorentinographic findings of normal a-wave and reduced b-wave amplitudes, we found prolonged b-wave latencies and implicit times, as well as a reduced 30 Hz flicker response.

  15. Library links on medical school home pages.

    Science.gov (United States)

    Thomas, Sheila L

    2011-01-01

    The purpose of this study was to assess the websites of American Association of Medical Colleges (AAMC)-member medical schools for the presence of library links. Sixty-one percent (n = 92) of home pages of the 150 member schools of the AAMC contain library links. For the 58 home pages not offering such links, 50 provided a pathway of two or three clicks to a library link. The absence of library links on 39% of AAMC medical school home pages indicates that the designers of those pages did not consider the library to be a primary destination for their visitors.

  16. Hacking 360 Link: A hybrid approach

    Directory of Open Access Journals (Sweden)

    John Durno

    2012-10-01

    Full Text Available When the University of Victoria Libraries switched from a locally-hosted link resolver (SFX to a vendor-hosted link resolver (360Link, new strategies were required to effectively integrate the vendor-hosted link resolver with the Libraries' other systems and services. Custom javascript is used to add links to the 360Link page; these links then point at local PHP code running on UVic servers, which can then redirect to appropriate local service or display a form directly. An open source PHP OpenURL parser class is announced. Consideration is given to the importance of maintaining open protocols and standards in the transition to vendor-hosted services.

  17. Adaptive link selection algorithms for distributed estimation

    Science.gov (United States)

    Xu, Songcen; de Lamare, Rodrigo C.; Poor, H. Vincent

    2015-12-01

    This paper presents adaptive link selection algorithms for distributed estimation and considers their application to wireless sensor networks and smart grids. In particular, exhaustive search-based least mean squares (LMS) / recursive least squares (RLS) link selection algorithms and sparsity-inspired LMS / RLS link selection algorithms that can exploit the topology of networks with poor-quality links are considered. The proposed link selection algorithms are then analyzed in terms of their stability, steady-state, and tracking performance and computational complexity. In comparison with the existing centralized or distributed estimation strategies, the key features of the proposed algorithms are as follows: (1) more accurate estimates and faster convergence speed can be obtained and (2) the network is equipped with the ability of link selection that can circumvent link failures and improve the estimation performance. The performance of the proposed algorithms for distributed estimation is illustrated via simulations in applications of wireless sensor networks and smart grids.

  18. Linking Diversity and Disparity Measures

    Directory of Open Access Journals (Sweden)

    Sahadeb Sarkar

    2012-07-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} The purpose of this paper is to examine links between the diversity measures (Patil and Taillie 1982 and the disparity measures (Lindsay 1994, quantities apparently developed for somewhat different purposes. We demonstrate that numerous diversity measures satisfying all the desirable criteria mentioned by Patil and Taillie can be defined by the generating functions of certain disparities and the associated residual adjustment functions. This provides the statistician and the ecologist a wide class of flexible indices for the statistical measurement of diversity.

  19. Corneal collagen cross-linking

    Directory of Open Access Journals (Sweden)

    Jankov II Mirko

    2010-01-01

    Full Text Available Corneal collagen cross-linking (CXL with riboflavin and ultraviolet-A (UVA is a new technique of corneal tissue strengthening by using riboflavin as a photosensitizer and UVA to increase the formation of intra- and interfibrillar covalent bonds by photosensitized oxidation. Keratocyte apoptosis in the anterior segment of the corneal stroma all the way down to a depth of about 300 microns has been described and a demarcation line between the treated and untreated cornea has been clearly shown. It is important to ensure that the cytotoxic threshold for the endothelium has not been exceeded by strictly respecting the minimal corneal thickness. Confocal microscopy studies show that repopulation of keratocytes is already visible 1 month after the treatment, reaching its pre-operative quantity and quality in terms of functional morphology within 6 months after the treatment. The major indication for the use of CXL is to inhibit the progression of corneal ectasias, such as keratoconus and pellucid marginal degeneration. CXL may also be effective in the treatment and prophylaxis of iatrogenic keratectasia, resulting from excessively aggressive photoablation. This treatment has also been used to treat infectious corneal ulcers with apparent favorable results. Combination with other treatments, such as intracorneal ring segment implantation, limited topography-guided photoablation and conductive keratoplasty have been used with different levels of success.

  20. Sirtuins Link Inflammation and Metabolism

    Directory of Open Access Journals (Sweden)

    Vidula T. Vachharajani

    2016-01-01

    Full Text Available Sirtuins (SIRT, first discovered in yeast as NAD+ dependent epigenetic and metabolic regulators, have comparable activities in human physiology and disease. Mounting evidence supports that the seven-member mammalian sirtuin family (SIRT1–7 guard homeostasis by sensing bioenergy needs and responding by making alterations in the cell nutrients. Sirtuins play a critical role in restoring homeostasis during stress responses. Inflammation is designed to “defend and mend” against the invading organisms. Emerging evidence supports that metabolism and bioenergy reprogramming direct the sequential course of inflammation; failure of homeostasis retrieval results in many chronic and acute inflammatory diseases. Anabolic glycolysis quickly induced (compared to oxidative phosphorylation for ROS and ATP generation is needed for immune activation to “defend” against invading microorganisms. Lipolysis/fatty acid oxidation, essential for cellular protection/hibernation and cell survival in order to “mend,” leads to immune repression. Acute/chronic inflammations are linked to altered glycolysis and fatty acid oxidation, at least in part, by NAD+ dependent function of sirtuins. Therapeutically targeting sirtuins may provide a new class of inflammation and immune regulators. This review discusses how sirtuins integrate metabolism, bioenergetics, and immunity during inflammation and how sirtuin-directed treatment improves outcome in chronic inflammatory diseases and in the extreme stress response of sepsis.

  1. Materializing the web of linked data

    CERN Document Server

    Konstantinou, Nikolaos

    2015-01-01

    This book explains the Linked Data domain by adopting a bottom-up approach: it introduces the fundamental Semantic Web technologies and building blocks, which are then combined into methodologies and end-to-end examples for publishing datasets as Linked Data, and use cases that harness scholarly information and sensor data. It presents how Linked Data is used for web-scale data integration, information management and search. Special emphasis is given to the publication of Linked Data from relational databases as well as from real-time sensor data streams. The authors also trace the transformation from the document-based World Wide Web into a Web of Data. Materializing the Web of Linked Data is addressed to researchers and professionals studying software technologies, tools and approaches that drive the Linked Data ecosystem, and the Web in general.

  2. A new representation of Links: Butterflies

    CERN Document Server

    Hilden, H M; Tejada, D M; Toro, M M

    2012-01-01

    With the idea of an eventual classification of 3-bridge links,\\ we define a very nice class of 3-balls (called butterflies) with faces identified by pairs, such that the identification space is $S^{3},$ and the image of a prefered set of edges is a link. Several examples are given. We prove that every link can be represented in this way (butterfly representation). We define the butterfly number of a link, and we show that the butterfly number and the bridge number of a link coincide. This is done by defining a move on the butterfly diagram. We give an example of two different butterflies with minimal butterfly number representing the knot $8_{20}.$ This raises the problem of finding a set of moves on a butterfly diagram connecting diagrams representing the same link. This is left as an open problem.

  3. New Optical Link Technologies for HEP Experiments

    CERN Document Server

    Delurgio, P; Salvachua, B; Lopez, D; Stanek, R; Underwood, D

    2011-01-01

    As a concern with the reliability and mass of current optical links in LHC experiments, we are investigating CW lasers and light modulators as an alternative to VCSELs. In addition we are developing data links in air, utilizing steering by MEMS mirrors and optical feedback paths for the control loop. Laser, modulator, and lens systems used are described, as well as two different electronic systems for a free space steering feedback loop. Our prototype system currently operates at 1.25 Gb/s, but could be upgraded. This link works over distances of order meters. Such links might enable one to move communication lasers (e.g. VCSELs) and optical fibers out of tracking detectors, for reasons such as reliability and power consumption. Some applications for free space data links, such as local triggering and data readout and trigger-clock distribution and links for much longer distances are also discussed.

  4. Community Detection Based on Link Prediction Methods

    CERN Document Server

    Cheng, Hui-Min

    2016-01-01

    Community detection and link prediction are both of great significance in network analysis, which provide very valuable insights into topological structures of the network from diffrent perspectives. In this paper, we propose a novel community detection algorithm with inclusion of link prediction, motivated by the question whether link prediction can be devoted to improve the accuracy of community partition. For link prediction, we propose two novel indices to compute the similarity between each pair of nodes, one of which aims to add missing links, and the other tries to remove spurious edges. Extensive experiments are conducted on benchmark data sets, and the results of our proposed algorithm are compared with two classes of baselines. In conclusion, our proposed algorithm is competitive, revealing that link prediction does improve the precision of community detection.

  5. Cascade of links in complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Yeqian; Sun, Bihui [Department of Management Science, School of Government, Beijing Normal University, 100875 Beijing (China); Zeng, An, E-mail: anzeng@bnu.edu.cn [School of Systems Science, Beijing Normal University, 100875 Beijing (China)

    2017-01-30

    Cascading failure is an important process which has been widely used to model catastrophic events such as blackouts and financial crisis in real systems. However, so far most of the studies in the literature focus on the cascading process on nodes, leaving the possibility of link cascade overlooked. In many real cases, the catastrophic events are actually formed by the successive disappearance of links. Examples exist in the financial systems where the firms and banks (i.e. nodes) still exist but many financial trades (i.e. links) are gone during the crisis, and the air transportation systems where the airports (i.e. nodes) are still functional but many airlines (i.e. links) stop operating during bad weather. In this letter, we develop a link cascade model in complex networks. With this model, we find that both artificial and real networks tend to collapse even if a few links are initially attacked. However, the link cascading process can be effectively terminated by setting a few strong nodes in the network which do not respond to any link reduction. Finally, a simulated annealing algorithm is used to optimize the location of these strong nodes, which significantly improves the robustness of the networks against the link cascade. - Highlights: • We propose a link cascade model in complex networks. • Both artificial and real networks tend to collapse even if a few links are initially attacked. • The link cascading process can be effectively terminated by setting a few strong nodes. • A simulated annealing algorithm is used to optimize the location of these strong nodes.

  6. micromap: A Package for Linked Micromaps

    OpenAIRE

    Quinn C. Payton; Michael G. McManus; Weber, Marc H.; Anthony R. Olsen; Thomas M. Kincaid

    2015-01-01

    The R package micromap is used to create linked micromaps, which display statistical summaries associated with areal units, or polygons. Linked micromaps provide a means to simultaneously summarize and display both statistical and geographic distributions by linking statistical summaries to a series of small maps. The package contains functions dependent on the ggplot2 package to produce a row-oriented graph composed of different panels, or columns, of information. These panels at a minimum t...

  7. Counting Links and Knots in Complete Graphs

    CERN Document Server

    Abrams, Loren

    2010-01-01

    We investigate the minimal number of links and knots in complete partite graphs. We provide exact values or bounds on the minimal number of links for all complete partite graphs with all but 4 vertices in one partition, or with 9 vertices in total. In particular, we find that the minimal number of links for $K_{4,4,1}$ is 74. We also provide exact values or bounds on the minimal number of knots for all complete partite graphs with 8 vertices.

  8. Coherent band pathways between knots and links

    CERN Document Server

    Buck, Dorothy

    2014-01-01

    We categorise coherent band (aka nullification) pathways between knots and 2-component links. Additionally, we characterise the minimal coherent band pathways (with intermediates) between any two knots or 2-component links with small crossing number. We demonstrate these band surgeries for knots and links with small crossing number. We apply these results to place lower bounds on the minimum number of recombinant events separating DNA configurations, restrict the recombination pathways and determine chirality and/or orientation of the resulting recombinant DNA molecules.

  9. Robotic manipulation with flexible link fingers

    OpenAIRE

    Sur, Sudipto

    1997-01-01

    A robot manipulator is a spatial mechanism consisting essentially of a series of bodies, called "links", connected to each other at "joints". The joints can be of various types: revolute, rotary, planar, prismatic, telescopic or combinations of these. A serial connection of the links results in an open-chain manipulator. Closed-chain manipulators result from non-serial (or parallel) connections between links. Actuators at the joints of the manipulator provide power for motion. A rob...

  10. Fast Link Adaptation for MIMO-OFDM

    DEFF Research Database (Denmark)

    Jensen, Tobias Lindstrøm; Kant, Shashi; Wehinger, Joachim;

    2010-01-01

    We investigate link-quality metrics (LQMs) based on raw bit-error-rate, effective signal-to-interference-plus-noise ratio, and mutual information (MI) for the purpose of fast link adaptation (LA) in communication systems employing orthogonal frequency-division multiplexing and multiple-input–mult......We investigate link-quality metrics (LQMs) based on raw bit-error-rate, effective signal-to-interference-plus-noise ratio, and mutual information (MI) for the purpose of fast link adaptation (LA) in communication systems employing orthogonal frequency-division multiplexing and multiple...

  11. Link prediction via generalized coupled tensor factorisation

    DEFF Research Database (Denmark)

    Ermiş, Beyza; Evrim, Acar Ataman; Taylan Cemgil, A.

    2012-01-01

    This study deals with the missing link prediction problem: the problem of predicting the existence of missing connections between entities of interest. We address link prediction using coupled analysis of relational datasets represented as heterogeneous data, i.e., datasets in the form of matrices...... different loss functions. Numerical experiments demonstrate that joint analysis of data from multiple sources via coupled factorisation improves the link prediction performance and the selection of right loss function and tensor model is crucial for accurately predicting missing links....

  12. LINKING STATE, UNIVERSITY AND BUSINESS IN NICARAGUA

    Directory of Open Access Journals (Sweden)

    Máximo Andrés Rodríguez Pérez

    2015-07-01

    Full Text Available In Nicaragua levels Linking state, university and business are low, Nicaraguan universities have initiated communication strategies with the state and the private sector. The idiosyncrasies of its citizens favor this link. The entailment policies formalize the communications and information networks. Universities have a key role in building models and organizations that provide alternatives to economic development. Linking the university with the environment, generating virtuous circles, where companies achieve greater competitiveness, the state, higher taxes and public stability, universities generate new knowledge. This article analyzes the strategies linking U-E- E that can be applied in Nicaragua, to strengthen and achieve positive developments in the country.

  13. Heuristic Decision Making in Network Linking

    NARCIS (Netherlands)

    M.J.W. Harmsen - Van Hout (Marjolein); B.G.C. Dellaert (Benedict); P.J.J. Herings (Jean-Jacques)

    2015-01-01

    textabstractNetwork formation among individuals constitutes an important part of many OR processes, but relatively little is known about how individuals make their linking decisions in networks. This article provides an investigation of heuristic effects in individual linking decisions for

  14. Exploring the obesity-asthma link

    DEFF Research Database (Denmark)

    Fenger, R V; Gonzalez-Quintela, A; Vidal, C;

    2012-01-01

    Obesity and risk of asthma are linked. Different distributions of adiposity, such as visceral, subcutaneous or ectopic adiposity, may affect asthma risk differently.......Obesity and risk of asthma are linked. Different distributions of adiposity, such as visceral, subcutaneous or ectopic adiposity, may affect asthma risk differently....

  15. CTS/Comstar communications link characterization experiment

    Science.gov (United States)

    Hodge, D. B.; Taylor, R. C.

    1980-01-01

    Measurements of angle of arrival and amplitude fluctuations on millimeter wavelength Earth-space communication links are described. Measurement of rainfall attenuation and radiometric temperature statistics and the assessment of the performance of a self-phased array as a receive antenna on an Earth-space link are also included.

  16. YASGUI: Feeling the Pulse of Linked Data

    NARCIS (Netherlands)

    Rietveld, L.; Hoekstra, R.

    2014-01-01

    Existing studies of Linked Data focus on the availability of data rather than its use in practice. The number of query logs available is very much restricted to a small number of datasets. This paper proposes to track Linked Data usage at the client side. We use YASGUI, a feature rich web-based quer

  17. Using linked data in Learning Analytics

    NARCIS (Netherlands)

    Mathieu, d'Aquin; Stefan, Dietze; Eelco, Herder; Hendrik, Drachsler; Davide, Taibi

    2014-01-01

    d’Aquin, M., Dietze, S., Herder, E., Drachsler, H., & Taibi, D. (2014). Using linked data in learning analytics. eLearning Papers. Nr. 36/2. ISSN: 1887-1542. http://www.openeducationeuropa.eu/en/article/Using-linked-data-in-Learning-Analytics?paper=134810

  18. Link-Net : improving railcar fleet management

    Energy Technology Data Exchange (ETDEWEB)

    Mancini, G.; Partington, M. [Procor Limited, Oakville, ON (Canada)

    1997-12-31

    Information about Link-Net, a new rail car information facility available on Netscape, was presented. Link-Net was developed by Ontario`s Procor Limited. It can be used to find a comprehensive list of data on rail fleet management, down to details about the status of single cars. 6 figs.

  19. Glue: Linked data visualizations across multiple files

    Science.gov (United States)

    Beaumont, Chris; Robitaille, Thomas; Borkin, Michelle

    2014-02-01

    Glue, written in Python, links visualizations of scientific datasets across many files, allowing for interactive, linked statistical graphics of multiple files. It supports many file formats including common image formats (jpg, tiff, png), ASCII tables, astronomical image and table formats (FITS, VOT, IPAC), and HDF5. Custom data loaders can also be easily added. Glue is highly scriptable and extendable.

  20. Biosimilars : linking quality data to clinical outcomes

    NARCIS (Netherlands)

    Halim, L.A.

    2016-01-01

    The aim of this study was to establish a link between quality attributes of biosimilars and potential clinical outcomes with regards to safety and immunogenicity. As we have access to multiple biosimilar and copy biologic products as well to patient data, the research involved linking comparative qu

  1. micromap: A Package for Linked Micromaps

    Directory of Open Access Journals (Sweden)

    Quinn C. Payton

    2015-02-01

    Full Text Available The R package micromap is used to create linked micromaps, which display statistical summaries associated with areal units, or polygons. Linked micromaps provide a means to simultaneously summarize and display both statistical and geographic distributions by linking statistical summaries to a series of small maps. The package contains functions dependent on the ggplot2 package to produce a row-oriented graph composed of different panels, or columns, of information. These panels at a minimum typically contain maps, a legend, and statistical summaries, with the color-coded legend linking the maps and statistical summaries. We first describe the layout of linked micromaps and then the structure required for both the spatial and statistical datasets. The function create_map_table in the micromap package converts the input of an sp SpatialPolygonsDataFrame into a data frame that can be linked with the statistical dataset. Highly detailed polygons are not appropriate for display in linked micromaps so we describe how polygon boundaries can be simplified, decreasing the time required to draw the graphs, while retaining adequate detail for detection of spatial patterns. Our worked examples of linked micromaps use public health data as well as environmental data collected from spatially balanced probabilistic surveys.

  2. Biosecurity--The Bio-Link Project.

    Science.gov (United States)

    Johnson, Elaine A.

    2002-01-01

    Describes Bio-Link, the Advanced Technological Education (ATE) Center for Biotechnology established with funding from the National Science Foundation (NSF). Reports that Bio-Link, headquartered at City College of San Francisco, has created a national network and resource base for community colleges, industry, and others interested in biotechnology…

  3. Causality and Borromean linking in twistor space

    Energy Technology Data Exchange (ETDEWEB)

    Low, Robert J, E-mail: mtx014@coventry.ac.uk [Department of Mathematics, Statistics and Engineering Science, Coventry University, Coventry CV1 5FB (United Kingdom)

    2011-10-01

    We consider the notion of the Borromean triple from classical linking theory, and develop an analogue of it in the case of linking of skies in twistor space. I would like to dedicate this paper to Roger Penrose, on the occasion of his 80th birthday.

  4. OCLC's Linking Strategy: Internet and NREN.

    Science.gov (United States)

    Electronic Library, 1992

    1992-01-01

    Summarizes OCLC's linking strategy for national networks, i.e., the Internet and the National Research and Education Network (NREN). The telecommunications environment for libraries is discussed and aspects of network links are considered, including governance, performance/support, economics, and future developments. Planning strategies for…

  5. Chemical cross-linking of Chlamydia trachomatis

    DEFF Research Database (Denmark)

    Birkelund, Svend; Lundemose, AG; Christiansen, Gunna

    1988-01-01

    Purified elementary bodies (EBs) of Chlamydia trachomatis serovar L2 were analyzed by chemical cross-linking with disuccinimidyl selenodipropionate. The effect of the cross-linking was analyzed by immunoblotting sodium dodecyl sulfate-polyacrylamide gel electrophoresis-separated components which...

  6. Using linked data in Learning Analytics

    NARCIS (Netherlands)

    Mathieu, d'Aquin; Stefan, Dietze; Eelco, Herder; Hendrik, Drachsler; Davide, Taibi

    2014-01-01

    d’Aquin, M., Dietze, S., Herder, E., Drachsler, H., & Taibi, D. (2014). Using linked data in learning analytics. eLearning Papers. Nr. 36/2. ISSN: 1887-1542. http://www.openeducationeuropa.eu/en/article/Using-linked-data-in-Learning-Analytics?paper=134810

  7. The Versatile Link Demo Board (VLDB)

    Science.gov (United States)

    Martín Lesma, R.; Alessio, F.; Barbosa, J.; Baron, S.; Caplan, C.; Leitao, P.; Pecoraro, C.; Porret, D.; Wyllie, K.

    2017-02-01

    The Versatile Link Demonstrator Board (VLDB) is the evaluation kit for the radiation-hard Optical Link ecosystem, which provides a 4.8 Gbps data transfer link for communication between front-end (FE) and back-end (BE) of the High Energy Physics experiments. It gathers the Versatile link main radiation-hard custom Application-Specific Integrated Circuits (ASICs) and modules: GBTx, GBT-SCA and VTRx/VTTx plus the FeastMP, a radiation-hard in-house designed DC-DC converter. This board is the first design allowing system-level tests of the Link with a complete interconnection of the constitutive components, allowing data acquisition, control and monitoring of FE devices with the GBT-SCA pair.

  8. Propagation engineering in radio links design

    CERN Document Server

    Ghasemi, Abdollah; Ghasemi, Farshid

    2013-01-01

    Propagation Engineering in Radio Link Design covers the basic principles of radiowaves propagation in a practical manner.  This fundamental understanding enables the readers to design radio links efficiently. This book elaborates on new achievements as well as recently developed propagation models.  This is in addition to a comprehensive overview of fundamentals of propagation in various scenarios. It examines theoretical calculations, approaches and applied procedures needed for radio links design. The authors study and analysis of the main propagation phenomena and its mechanisms based on the recommendations of International Telecommunications Union, (ITU). The book has been organized in 9 chapters and examines the role of antennas and passive reflectors in radio services, propagation mechanisms related to radar, satellite, short distance, broadcasting and trans-horizon radio links, with two chapters devoted to radio noise and main  parameters of radio link design. The book presents some 278 illustration...

  9. Mapping the x-linked lymphoproliferative syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Skare, J.C.; Milunsky, A.; Byron, K.S.; Sullivan, J.L.

    1987-04-01

    The X-linked lymphoproliferative syndrome is triggered by Epstein-Barr virus infection and results in fatal mononucleosis, immunodeficiency, and lymphoproliferative disorders. This study shows that the mutation responsible for X-linked lymphoproliferative syndrome is genetically linked to a restriction fragment length polymorphism detected with the DXS42 probe (from Xq24-q27). The most likely recombination frequency between the loci is 4%, and the associated logarithm of the odds is 5.26. Haplotype analysis using flanking restriction fragment length polymorphism markers indicates that the locus for X-linked lymphoproliferative syndrome is distal to probe DXS42 but proximal to probe DXS99 (from Xq26-q27). It is now possible to predict which members of a family with X-linked lymphoproliferative syndrome are carrier females and to diagnose the syndrome prenatally.

  10. The Link Prediction Problem in Bipartite Networks

    CERN Document Server

    Kunegis, Jérôme; Albayrak, Sahin

    2010-01-01

    We define and study the link prediction problem in bipartite networks, specializing general link prediction algorithms to the bipartite case. In a graph, a link prediction function of two vertices denotes the similarity or proximity of the vertices. Common link prediction functions for general graphs are defined using paths of length two between two nodes. Since in a bipartite graph adjacency vertices can only be connected by paths of odd lengths, these functions do not apply to bipartite graphs. Instead, a certain class of graph kernels (spectral transformation kernels) can be generalized to bipartite graphs when the positive-semidefinite kernel constraint is relaxed. This generalization is realized by the odd component of the underlying spectral transformation. This construction leads to several new link prediction pseudokernels such as the matrix hyperbolic sine, which we examine for rating graphs, authorship graphs, folksonomies, document--feature networks and other types of bipartite networks.

  11. Ubiquitousness of link-density and link-pattern communities in real-world networks

    CERN Document Server

    Šubelj, Lovro

    2011-01-01

    Community structure appears to be an intrinsic property of many complex real-world networks. However, recent work shows that real-world networks reveal even more sophisticated modules than classical cohesive (link-density) communities. In particular, networks can also be naturally partitioned according to similar patterns of connectedness between the nodes, revealing link-pattern communities. We here propose a balanced propagation based algorithm that can extract both link-density and link-pattern communities, without any prior knowledge of the true structure. The algorithm was first validated on different classes of synthetic benchmark networks with community structure, and also on random networks. We have then further applied the algorithm to different social, information, technological and biological networks, where it indeed reveals meaningful (composites of) link-density and link-pattern communities. The results thus seem to imply that, similarly as link-density counterparts, link-pattern communities app...

  12. Web Applications of Bibliometrics and Link Analysis

    Directory of Open Access Journals (Sweden)

    Faribourz Droudi

    2010-04-01

    Full Text Available The present study aims to introduce and analyze bibliometric application within Web and also to expounds on the status of link analysis in order to point out its application with respect to the existing web-based information sources. Findings indicate that bibliometrics could have required application in the area of digital resources available through Net. Link analysis is a process by which one could make statistical analysis of correlation between hyperlinks and therefore understand the accuracy, veracity and efficacy of citations within a digital document. Link analysis, in effect, is counted as a part of information ranking algorithm within the web environment. The number, linkage and quality of given links to a website are of utmost importance for ranking/status in the Web. The tools applied in this topic include, page ranking strategy, link analysis algorithm, latent semantic indexing and the classical input-output model. The present study analyzes Big Web and Small Web link analysis and explains the means for utilizing web charts in order to better understand the link analysis process.

  13. Predicting Anchor Links between Heterogeneous Social Networks

    CERN Document Server

    Sajadmanesh, Sina; Khodadadi, Ali

    2016-01-01

    People usually get involved in multiple social networks to enjoy new services or to fulfill their needs. Many new social networks try to attract users of other existing networks to increase the number of their users. Once a user (called source user) of a social network (called source network) joins a new social network (called target network), a new inter-network link (called anchor link) is formed between the source and target networks. In this paper, we concentrated on predicting the formation of such anchor links between heterogeneous social networks. Unlike conventional link prediction problems in which the formation of a link between two existing users within a single network is predicted, in anchor link prediction, the target user is missing and will be added to the target network once the anchor link is created. To solve this problem, we use meta-paths as a powerful tool for utilizing heterogeneous information in both the source and target networks. To this end, we propose an effective general meta-pat...

  14. Link Characteristics and Forecast for Internet Users

    Institute of Scientific and Technical Information of China (English)

    JINZhigang; LUOYongmei

    2004-01-01

    For a user sharing Internet resources the “Weather Forecast” of the Internet is important. As a user, he has no right to access the status of routers/switches and has not enough information about the overall network. In order to give users useful information and the forecast, this paper proposes a new approach to measure and forecast Internet link status and Local area network (LAN) traffic. In this paper, the design and implementation of a user-oriented, generalized system are proposed for characterizing the links and producing short-term performance forecasts based on historical link characteristics. Pathchar, packet pair are used to measure the latency of hops along a link, and TCPdump is used to collect the traffic of the local LAN. When using these measurement tools in appropriate time scales, we can set up a set of indicators for link status and do prediction for the link characteristics in the future. To improve the accuracy of the estimate of bandwidth, the Extreme value theory (EVT) is deployed. The experimental data show the feasibility of EVT filters. The data show that the EVT resuits are more close to nominal bandwidth. The FARIMA (p,d,q) (fractional autoregressive integrated moving average) based prediction is also presented to forecast the furure status of links and the local traffic.

  15. What Makes a Link Successful on Wikipedia?

    CERN Document Server

    Dimitrov, Dimitar; Lemmerich, Florian; Strohmaier, Markus

    2016-01-01

    While a plethora of hypertext links exist on the Web, only a small amount of them are regularly clicked. Starting from this observation, we set out to study large-scale click data from Wikipedia in order to understand what makes a link successful. We systematically analyze effects of link properties on the popularity of links. By utilizing mixed-effects hurdle models supplemented with descriptive insights, we find evidence of user preference towards links leading to the periphery of the network, towards links leading to semantically similar articles, and towards links in the top and left-side of the screen. We integrate these findings as Bayesian priors into a navigational Markov chain model and by doing so successfully improve the model fits. We further adapt and improve the well-known classic PageRank algorithm that assumes random navigation by accounting for observed navigational preferences of users in a weighted variation. This work facilitates understanding navigational click behavior and thus can contr...

  16. Jamming Technique to Link 11 Data Link%Link 11数据链干扰技术

    Institute of Scientific and Technical Information of China (English)

    刘万洪; 蔡啸; 王烟青

    2007-01-01

    Link 11数据链的数学模型入手,分析其在噪声干扰、单音干扰、多音干扰等下的误码性能.仿真结论表明,对Link 11的干扰技术中,不论采用噪声干扰,或者是采用单音或多音干扰,只要掌握其工作原理,就可以采取适当方式对其进行干扰.从另一方面可以看出,Link 11由于易损性等原因,已经暴露了许多不尽人意的缺点,一种新型的数据链--Link 22产生,并对其特点作了简单分析.

  17. Novel fat-link fermion actions

    CERN Document Server

    Zanotti, J M; Bonnet, F D R; Coddington, P D; Leinweber, D B; Williams, A G; Zhang, J B; Melnitchouk, W; Lee, F X

    2002-01-01

    The hadron mass spectrum is calculated in lattice QCD using a novel fat-link clover fermion action in which only the irrelevant operators of the fermion action are constructed using smeared links. The simulations are performed on a 16^3 X 32 lattice with a lattice spacing of a=0.125 fm. We compare actions with n=4 and 12 smearing sweeps with a smearing fraction of 0.7. The n=4 Fat Link Irrelevant Clover (FLIC) action provides scaling which is superior to mean-field improvement, and offers advantages over nonperturbative O(a) improvement.

  18. The Gigabit Link Interface Board (GLIB) ecosystem

    CERN Document Server

    Vichoudis, P; Baron, S; Barros Marin, M; Bobillier, V; Chramowitz, J; Haas, S; Hansen, M; Joos, M; Lobato Pardavila, L; Petit, P; Prosser, A; Vasey, F

    2013-01-01

    The Gigabit Link Interface Board (GLIB) project is an FPGA-based platform for users of high-speed optical links in high energy physics experiments. The major hardware component of the platform is the GLIB Advanced Mezzanine Card (AMC). Additionally to the AMC, auxiliary components are developed that enhance GLIB platform's I/O bandwidth and compatibility with legacy and future triggering and/or data acquisition interfaces. This article focuses on the development of the auxiliary components that together with the GLIB AMC offer a complete solution for beam/irradiation tests of detector modules and evaluation of optical links.

  19. External Link Policy | Division of Cancer Prevention

    Science.gov (United States)

    The following graphic notice means that you are leaving the DCP Web site: (link is external)This external link provides additional information that is consistent with the intended purpose of DCP.The National Cancer Institute (NCI) cannot attest to the accuracy of a non-federal site.Linking to a non-federal site does not constitute an endorsement by HHS or any of its employees of the sponsors or the information and products presented on the site.You will be subject to the destination site |

  20. Mobile Recommendation Based on Link Community Detection

    Directory of Open Access Journals (Sweden)

    Kun Deng

    2014-01-01

    Full Text Available Since traditional mobile recommendation systems have difficulty in acquiring complete and accurate user information in mobile networks, the accuracy of recommendation is not high. In order to solve this problem, this paper proposes a novel mobile recommendation algorithm based on link community detection (MRLD. MRLD executes link label diffusion algorithm and maximal extended modularity (EQ of greedy search to obtain the link community structure, and overlapping nodes belonging analysis (ONBA is adopted to adjust the overlapping nodes in order to get the more accurate community structure. MRLD is tested on both synthetic and real-world networks, and the experimental results show that our approach is valid and feasible.

  1. Link Prediction in Complex Networks: A Survey

    CERN Document Server

    Lu, Linyuan

    2010-01-01

    Link prediction in complex networks has attracted increasing attention from both physical and computer science communities. The algorithms can be used to extract missing information, identify spurious interactions, evaluate network evolving mechanisms, and so on. This article summaries recent progress about link prediction algorithms, emphasizing on the contributions from physical perspectives and approaches, such as the random-walk-based methods and the maximum likelihood methods. We also introduce three typical applications: reconstruction of networks, evaluation of network evolving mechanism and classification of partially labelled networks. Finally, we introduce some applications and outline future challenges of link prediction algorithms.

  2. Link mining models, algorithms, and applications

    CERN Document Server

    Yu, Philip S; Faloutsos, Christos

    2010-01-01

    This book presents in-depth surveys and systematic discussions on models, algorithms and applications for link mining. Link mining is an important field of data mining. Traditional data mining focuses on 'flat' data in which each data object is represented as a fixed-length attribute vector. However, many real-world data sets are much richer in structure, involving objects of multiple types that are related to each other. Hence, recently link mining has become an emerging field of data mining, which has a high impact in various important applications such as text mining, social network analysi

  3. Best practices for publishing linked data

    OpenAIRE

    World Wide Web Consortium

    2014-01-01

    Este documento establece una serie de buenas prácticas destinadas a facilitar el desarrollo y la entrega de los datos de gobierno abierto como Linked Open Data. Linked Open Data convierte a la World Wide Web en una base de datos global, a veces denominada como "Web de datos". Utilizando los principios de Linked Data, los desarrolladores pueden consultar datos enlazados provenientes de múltiples fuentes a la vez y combinarlos sin la necesidad de un único esquema común que todos los datos compa...

  4. Covalently linked tandem lesions in DNA.

    Science.gov (United States)

    Patrzyc, Helen B; Dawidzik, Jean B; Budzinski, Edwin E; Freund, Harold G; Wilton, John H; Box, Harold C

    2012-12-01

    Reactive oxygen species (ROS) generate a type of DNA damage called tandem lesions, two adjacent nucleotides both modified. A subcategory of tandem lesions consists of adjacent nucleotides linked by a covalent bond. Covalently linked tandem lesions generate highly characteristic liquid chromotography-tandem mass spectrometry (LC-MS/MS) elution profiles. We have used this property to comprehensively survey X-irradiated DNA for covalently linked tandem lesions. A total of 15 tandem lesions were detected in DNA irradiated in deoxygenated aqueous solution, five tandem lesions were detected in DNA that was irradiated in oxygenated solution.

  5. Service Migration Protocol for NFC Links

    DEFF Research Database (Denmark)

    Nickelsen, Anders; Schwefel, Hans-Peter; Martin, Miquel

    2010-01-01

    of use while preserving state. This paper focuses on the scenario of migration between two devices in which the actual migration procedure is executed over near-field communication (NFC) ad-hoc links. The NFC link is interesting as it gives the user the perception of trust and enables service continuity...... in cases where mid- or long-range wireless connectivity is unavailable. Based on an experimental performance analysis of a specific NFC platform, the paper presents a migration orchestration protocol with low overhead and low delays to be used with NFC links. Experimental results allow to conclude...

  6. The effect of cross-link distributions in axially-ordered, cross-linked networks

    Science.gov (United States)

    Bennett, C. Brad; Kruczek, James; Rabson, D. A.; Matthews, W. Garrett; Pandit, Sagar A.

    2013-07-01

    Cross-linking between the constituent chains of biopolymers has a marked effect on their materials’ properties. In certain of these materials, such as fibrillar collagen, increases in cross-linking lead to an increase in the melting temperature. Fibrillar collagen is an axially-ordered network of cross-linked polymer chains exhibiting a broadened denaturation transition, which has been explained in terms of the successive denaturation with temperature of multiple species. We model axially-ordered, cross-linked materials as stiff chains with distinct arrangements of cross-link-forming sites. Simulations suggest that systems composed of chains with identical arrangements of cross-link-forming sites exhibit critical behavior. In contrast, systems composed of non-identical chains undergo a crossover. This model suggests that the arrangement of cross-link-forming sites may contribute to the broadening of the denaturation transition in fibrillar collagen.

  7. Discriminative Link Prediction using Local Links, Node Features and Community Structure

    CERN Document Server

    De, Abir; Chakrabarti, Soumen

    2013-01-01

    A link prediction (LP) algorithm is given a graph, and has to rank, for each node, other nodes that are candidates for new linkage. LP is strongly motivated by social search and recommendation applications. LP techniques often focus on global properties (graph conductance, hitting or commute times, Katz score) or local properties (Adamic-Adar and many variations, or node feature vectors), but rarely combine these signals. Furthermore, neither of these extremes exploit link densities at the intermediate level of communities. In this paper we describe a discriminative LP algorithm that exploits two new signals. First, a co-clustering algorithm provides community level link density estimates, which are used to qualify observed links with a surprise value. Second, links in the immediate neighborhood of the link to be predicted are not interpreted at face value, but through a local model of node feature similarities. These signals are combined into a discriminative link predictor. We evaluate the new predictor usi...

  8. Linked-OWL: A new approach for dynamic linked data service workflow composition

    Directory of Open Access Journals (Sweden)

    Hussien Ahmad

    2013-06-01

    Full Text Available The shift from Web of Document into Web of Data based on Linked Data principles defined by Tim Berners-Lee posed a big challenge to build and develop applications to work in Web of Data environment. There are several attempts to build service and application models for Linked Data Cloud. In this paper, we propose a new service model for linked data "Linked-OWL" which is based on RESTful services and OWL-S and copes with linked data principles. This new model shifts the service concept from functions into linked data things and opens the road for Linked Oriented Architecture (LOA and Web of Services as part and on top of Web of Data. This model also provides high level of dynamic service composition capabilities for more accurate dynamic composition and execution of complex business processes in Web of Data environment.

  9. Prenatal Inflammation Linked to Autism Risk

    Science.gov (United States)

    ... Thursday, January 24, 2013 Prenatal inflammation linked to autism risk Maternal inflammation during early pregnancy may be related to an increased risk of autism in children, according to new findings supported by ...

  10. Gallstones Linked to Higher Heart Disease Risk

    Science.gov (United States)

    ... news/fullstory_160497.html Gallstones Linked to Higher Heart Disease Risk Researcher says study highlights a connection between ... may have a slightly increased risk of developing heart disease down the road, a large new study suggests. ...

  11. Linking Medicare, Medicaid, and Cancer Registry Data...

    Data.gov (United States)

    U.S. Department of Health & Human Services — Linking Medicare, Medicaid, and Cancer Registry Data to Study the Burden of Cancers in West Virginia In the United States, the elderly carry an unequal burden of...

  12. Mercury Poisoning Linked to Skin Products

    Science.gov (United States)

    ... Products For Consumers Home For Consumers Consumer Updates Mercury Poisoning Linked to Skin Products Share Tweet Linkedin ... situations, criminal prosecution. back to top Dangers of Mercury Exposure to mercury can have serious health consequences. ...

  13. Linking Medicare, Medicaid, and Cancer Registry Data...

    Data.gov (United States)

    U.S. Department of Health & Human Services — Linking Medicare, Medicaid, and Cancer Registry Data to Study the Burden of Cancers in West Virginia In the United States, the elderly carry an unequal burden of...

  14. Many Chronic Illnesses Linked to Suicide Risk

    Science.gov (United States)

    ... fullstory_166776.html Many Chronic Illnesses Linked to Suicide Risk Odds 9 times higher for people with ... problems seem to have a higher risk of suicide, a new study suggests. And, for certain conditions -- ...

  15. More Evidence Linking Obesity to Liver Cancer

    Science.gov (United States)

    ... fullstory_161494.html More Evidence Linking Obesity to Liver Cancer And type 2 diabetes more than doubles the ... type 2 diabetes, may raise your risk for liver cancer, a new study suggests. "We found that each ...

  16. Predicting missing links via correlation between nodes

    CERN Document Server

    Liao, Hao; Zhang, Yi-Cheng

    2014-01-01

    As a fundamental problem in many different fields, link prediction aims to estimate the likelihood of an existing link between two nodes based on the observed information. Since this problem is related to many applications ranging from uncovering missing data to predicting the evolution of networks, link prediction has been intensively investigated recently and many methods have been proposed so far. The essential challenge of link prediction is to estimate the similarity between nodes. Most of the existing methods are based on the common neighbor index and its variants. In this paper, we propose to calculate the similarity between nodes by the correlation coefficient. This method is found to be very effective when applied to calculate similarity based on high order paths. We finally fuse the correlation-based method with the resource allocation method, and find that the combined method can substantially outperform the existing methods, especially in sparse networks.

  17. Tackling the Limits of Optical Fiber Links

    CERN Document Server

    Stefani, Fabio; Bercy, Anthony; Lee, Won-Kyu; Chardonnet, Christian; Santarelli, Giorgio; Pottie, Paul-Eric; Amy-Klein, Anne

    2014-01-01

    We theoretically and experimentally investigate relevant noise processes arising in optical fiber links, which fundamentally limit their relative stability. We derive the unsuppressed delay noise for three configurations of optical links: two-way method, Sagnac interferometry, and actively compensated link, respectively designed for frequency comparison, rotation sensing, and frequency transfer. We also consider an alternative two-way setup allowing real-time frequency comparison and demonstrate its effectiveness on a proof-of-principle experiment with a 25-km fiber spool. For these three configurations, we analyze the noise arising from uncommon fiber paths in the interferometric ensemble and design optimized interferometers. We demonstrate interferometers with very low temperature sensitivity of respectively -2.2, -0.03 and 1 fs/K. We use one of these optimized interferometers on a long haul compensated fiber link of 540km. We obtain a relative frequency stability of 3E-20 after 10,000 s of integration time...

  18. Cellular Defect May Be Linked to Parkinson's

    Science.gov (United States)

    ... 160862.html Cellular Defect May Be Linked to Parkinson's: Study Abnormality might apply to all forms of ... that may be common to all forms of Parkinson's disease. The defect plays a major role in ...

  19. Heart Disease Linked to Anxiety, Negative Feelings

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_163702.html Heart Disease Linked to Anxiety, Negative Feelings And that's especially ... Feb. 21, 2017 (HealthDay News) -- People with mild heart disease are more likely to say they have poorer ...

  20. Link Seen Between Concussions and Alzheimer's

    Science.gov (United States)

    ... fullstory_163025.html Link Seen Between Concussions and Alzheimer's But study didn't prove head injuries cause ... mental decline of people already at risk for Alzheimer's disease? In a new study, researchers examined 160 ...

  1. Using Linked Data in Learning Analytics

    NARCIS (Netherlands)

    d'Aquin, Mathieu; Dietze, Stefan; Drachsler, Hendrik; Herder, Eelco

    2013-01-01

    d'Aquin, M., Dietze, S., Drachsler, H., & Herder, E. (2013, April). Using Linked Data in Learning Analytics. Tutorial given at LAK 2013, the Third Conference on Learning Analytics and Knowledge, Leuven, Belgium.

  2. Bounded link prediction in very large networks

    Science.gov (United States)

    Cui, Wei; Pu, Cunlai; Xu, Zhongqi; Cai, Shimin; Yang, Jian; Michaelson, Andrew

    2016-09-01

    Evaluating link prediction methods is a hard task in very large complex networks due to the prohibitive computational cost. However, if we consider the lower bound of node pairs' similarity scores, this task can be greatly optimized. In this paper, we study CN index in the bounded link prediction framework, which is applicable to enormous heterogeneous networks. Specifically, we propose a fast algorithm based on the parallel computing scheme to obtain all node pairs with CN values larger than the lower bound. Furthermore, we propose a general measurement, called self-predictability, to quantify the performance of similarity indices in link prediction, which can also indicate the link predictability of networks with respect to given similarity indices.

  3. Too Much Iron Linked to Gestational Diabetes

    Science.gov (United States)

    ... fullstory_161946.html Too Much Iron Linked to Gestational Diabetes Supplements should only be given to pregnant women ... an increased risk of developing diabetes during pregnancy (gestational diabetes), begging the question whether routine recommendations of iron ...

  4. Development Issues on Linked Data Weblog Enrichment

    Science.gov (United States)

    Ruiz-Rube, Iván; Cornejo, Carlos M.; Dodero, Juan Manuel; García, Vicente M.

    In this paper, we describe the issues found during the development of LinkedBlog, a Linked Data extension for WordPress blogs. This extension enables to enrich text-based and video information contained in blog entries with RDF triples that are suitable to be stored, managed and exploited by other web-based applications. The issues have to do with the generality, usability, tracking, depth, security, trustiness and performance of the linked data enrichment process. The presented annotation approach aims at maintaining web-based contents independent from the underlying ontological model, by providing a loosely coupled RDFa-based approach in the linked data application. Finally, we detail how the performance of annotations can be improved through a semantic reasoner.

  5. A Robust Parsing Algorithm For Link Grammars

    CERN Document Server

    Grinberg, D; Sleator, D; Grinberg, Dennis; Lafferty, John; Sleator, Daniel

    1995-01-01

    In this paper we present a robust parsing algorithm based on the link grammar formalism for parsing natural languages. Our algorithm is a natural extension of the original dynamic programming recognition algorithm which recursively counts the number of linkages between two words in the input sentence. The modified algorithm uses the notion of a null link in order to allow a connection between any pair of adjacent words, regardless of their dictionary definitions. The algorithm proceeds by making three dynamic programming passes. In the first pass, the input is parsed using the original algorithm which enforces the constraints on links to ensure grammaticality. In the second pass, the total cost of each substring of words is computed, where cost is determined by the number of null links necessary to parse the substring. The final pass counts the total number of parses with minimal cost. All of the original pruning techniques have natural counterparts in the robust algorithm. When used together with memoization...

  6. Using Linked Data in Learning Analytics

    NARCIS (Netherlands)

    d'Aquin, Mathieu; Dietze, Stefan; Drachsler, Hendrik; Herder, Eelco

    2013-01-01

    d'Aquin, M., Dietze, S., Drachsler, H., & Herder, E. (2013, April). Using Linked Data in Learning Analytics. Tutorial given at LAK 2013, the Third Conference on Learning Analytics and Knowledge, Leuven, Belgium.

  7. Diabetes and gastric cancer: The potential links

    OpenAIRE

    Tseng, Chin-Hsiao; Tseng, Farn-Hsuan

    2014-01-01

    This article reviews the epidemiological evidence linking diabetes and gastric cancer and discusses some of the potential mechanisms, confounders and biases in the evaluation of such an association. Findings from four meta-analyses published from 2011 to 2013 suggest a positive link, which may be more remarkable in females and in the Asian populations. Putative mechanisms may involve shared risk factors, hyperglycemia, Helicobacter pylori (H. pylori) infection, high salt intake, medications a...

  8. Negative Link Prediction in Social Media

    OpenAIRE

    Tang, Jiliang; Chang, Shiyu; Aggarwal, Charu; Liu, Huan

    2014-01-01

    Signed network analysis has attracted increasing attention in recent years. This is in part because research on signed network analysis suggests that negative links have added value in the analytical process. A major impediment in their effective use is that most social media sites do not enable users to specify them explicitly. In other words, a gap exists between the importance of negative links and their availability in real data sets. Therefore, it is natural to explore whether one can pr...

  9. Star repeaters for fiber optic links.

    Science.gov (United States)

    McMahon, D H; Gravel, R L

    1977-02-01

    A star repeater combines the functions of a passive star coupler and a signal regenerating amplifier. By more effectively utilizing the light power radiated by a light emitting diode, the star repeater can, when used with small diameter channels, couple as much power to all receivers of a multiterminal link as would be coupled to the single receiver of a simple point-to-point link.

  10. Microwaves photonic links components and circuits

    CERN Document Server

    Rumelhard, Christian; Billabert, Anne-Laure

    2013-01-01

    This book presents the electrical models for the different elements of a photonic microwave link like lasers, external modulators, optical fibers, photodiodes and phototransistors. The future trends of these components are also introduced: lasers to VCSEL, external modulators to electro-absorption modulators, glass optical fibers to plastic optical fibers, photodiodes to UTC photodiodes or phototransistors. It also describes an original methodology to evaluate the performance of a microwave photonic link, based on the developed elcetrical models, that can be easily incorporated in

  11. Network Communication by Optical Directional Link

    Directory of Open Access Journals (Sweden)

    V. Biolkova

    1999-04-01

    Full Text Available In this article, infrared point-to-point technologies (optical directional links are discussed which are designed for digital transmissions. Optical directional links (ODLs are transparent for the SDH/ATM, FDDI-II, Ethernet, and Token Ring protocols. Depending on type, ODL ranges are 300 m, 500 m, 1000 m and 2000 m. Steady and statistical models of ODL are presented as well as the measuring ODL arrangement and the graphs concerning the fluctuations of the received signal.

  12. The missing link between values and behaviour

    DEFF Research Database (Denmark)

    Brunsø, Karen

    For a long time human values have been perceived as abstrat cognitions representing desired goals or end-states which motivate humnan behaviour. A number of studies have tried to explore the link between values and behaviour, but often different constructs are included as intermediate links betwe...... and lifestyle and behaviour. Based on this appraoch we collected data covering values, lifestyle and behaviour, and estimated the cogntiive hierarchy from values to lifestyle to behaviour by structural equation models....

  13. Energy: The Link between GDP and Emissions

    OpenAIRE

    Jan-Erik Lane

    2013-01-01

    The global energy-environment conundrum unfolds now with more and more evidence confirming the climate change hypothesis. The accumulation of greenhouses gases in the atmosphere is strongly linked with economic production, the GDP indicator. Here we give the exact relationships between GDP, energy consumption and greenhouse gases emissions, over time and cross-sectionally for the entire globe. The intermediating link between total GDP and total emissions is, it must be emphasized, the energy ...

  14. Polybinary modulation for bandwidth limited optical links

    DEFF Research Database (Denmark)

    Vegas Olmos, Juan José; Jurado-Navas, Antonio

    2015-01-01

    Optical links using traditional modulation formats are reaching a plateau in terms of capacity, mainly due to bandwidth limitations in the devices employed at the transmitter and receivers. Advanced modulation formats, which boost the spectral efficiency, provide a smooth migration path towards...... the recent results on poly binary modulation, comprising both binary and multilevel signals as seed signals. The results will show how poly binary modulation effectively reduces the bandwidth requirements on optical links while providing high spectral efficiency....

  15. Khovanov homology of links and graphs

    Science.gov (United States)

    Stosic, Marko

    2006-05-01

    In this thesis we work with Khovanov homology of links and its generalizations, as well as with the homology of graphs. Khovanov homology of links consists of graded chain complexes which are link invariants, up to chain homotopy, with graded Euler characteristic equal to the Jones polynomial of the link. Hence, it can be regarded as the "categorification" of the Jones polynomial. We prove that the first homology group of positive braid knots is trivial. Futhermore, we prove that non-alternating torus knots are homologically thick. In addition, we show that we can decrease the number of full twists of torus knots without changing low-degree homology and consequently that there exists stable homology for torus knots. We also prove most of the above properties for Khovanov-Rozansky homology. Concerning graph homology, we categorify the dichromatic (and consequently Tutte) polynomial for graphs, by categorifying an infinite set of its one-variable specializations. We categorify explicitly the one-variable specialization that is an analog of the Jones polynomial of an alternating link corresponding to the initial graph. Also, we categorify explicitly the whole two-variable dichromatic polynomial of graphs by using Koszul complexes. textbf{Key-words:} Khovanov homology, Jones polynomial, link, torus knot, graph, dichromatic polynomial

  16. Emerging semantics to link phenotype and environment

    Directory of Open Access Journals (Sweden)

    Anne E. Thessen

    2015-12-01

    Full Text Available Understanding the interplay between environmental conditions and phenotypes is a fundamental goal of biology. Unfortunately, data that include observations on phenotype and environment are highly heterogeneous and thus difficult to find and integrate. One approach that is likely to improve the status quo involves the use of ontologies to standardize and link data about phenotypes and environments. Specifying and linking data through ontologies will allow researchers to increase the scope and flexibility of large-scale analyses aided by modern computing methods. Investments in this area would advance diverse fields such as ecology, phylogenetics, and conservation biology. While several biological ontologies are well-developed, using them to link phenotypes and environments is rare because of gaps in ontological coverage and limits to interoperability among ontologies and disciplines. In this manuscript, we present (1 use cases from diverse disciplines to illustrate questions that could be answered more efficiently using a robust linkage between phenotypes and environments, (2 two proof-of-concept analyses that show the value of linking phenotypes to environments in fishes and amphibians, and (3 two proposed example data models for linking phenotypes and environments using the extensible observation ontology (OBOE and the Biological Collections Ontology (BCO; these provide a starting point for the development of a data model linking phenotypes and environments.

  17. Effect of Link Flexibility on tip position of a single link robotic arm

    Science.gov (United States)

    Madhusudan Raju, E.; Siva Rama Krishna, L.; Mouli, Y. Sharath Chandra; Nageswara Rao, V.

    2015-12-01

    The flexible robots are widely used in space applications due to their quick response, lower energy consumption, lower overall mass and operation at high speed compared to conventional industrial rigid link robots. These robots are inherently flexible, so that the kinematics of flexible robots can't be solved with rigid body assumptions. The flexibility in links and joints affects end-point positioning accuracy of the robot. It is important to model the link kinematics with precision which in turn simplifies modelling of dynamics of flexible robots. The main objective of this paper is to evaluate the effect of link flexibility on a tip position of a single link robotic arm for a given motion. The joint is assumed to be rigid and only link flexibility is considered. The kinematics of flexible link problem is evaluated by Assumed Modes Method (AMM) using MAT LAB Programming. To evaluate the effect of link flexibility (with and without payload) of robotic arm, the normalized tip deviation is found for flexible link with respect to a rigid link. Finally, the limiting inertia for payload mass is found if the allowable tip deviation is 5%.

  18. Link Analysis in the Mission Planning Lab

    Science.gov (United States)

    McCarthy, Jessica A.; Cervantes, Benjamin W.; Daugherty, Sarah C.; Arroyo, Felipe; Mago, Divyang

    2011-01-01

    The legacy communications link analysis software currently used at Wallops Flight Facility involves processes that are different for command destruct, radar, and telemetry. There is a clear advantage to developing an easy-to-use tool that combines all the processes in one application. Link Analysis in the Mission Planning Lab (MPL) uses custom software and algorithms integrated with Analytical Graphics Inc. Satellite Toolkit (AGI STK). The MPL link analysis tool uses pre/post-mission data to conduct a dynamic link analysis between ground assets and the launch vehicle. Just as the legacy methods do, the MPL link analysis tool calculates signal strength and signal- to-noise according to the accepted processes for command destruct, radar, and telemetry assets. Graphs and other custom data are generated rapidly in formats for reports and presentations. STK is used for analysis as well as to depict plume angles and antenna gain patterns in 3D. The MPL has developed two interfaces with the STK software (see figure). The first interface is an HTML utility, which was developed in Visual Basic to enhance analysis for plume modeling and to offer a more user friendly, flexible tool. A graphical user interface (GUI) written in MATLAB (see figure upper right-hand corner) is also used to quickly depict link budget information for multiple ground assets. This new method yields a dramatic decrease in the time it takes to provide launch managers with the required link budgets to make critical pre-mission decisions. The software code used for these two custom utilities is a product of NASA's MPL.

  19. Link!: Potential Field Guidance Algorithm for In-Flight Linking of Multi-Rotor Aircraft

    Science.gov (United States)

    Cooper, John R.; Rothhaar, Paul M.

    2017-01-01

    Link! is a multi-center NASA e ort to study the feasibility of multi-aircraft aerial docking systems. In these systems, a group of vehicles physically link to each other during flight to form a larger ensemble vehicle with increased aerodynamic performance and mission utility. This paper presents a potential field guidance algorithm for a group of multi-rotor vehicles to link to each other during flight. The linking is done in pairs. Each vehicle first selects a mate. Then the potential field is constructed with three rules: move towards the mate, avoid collisions with non-mates, and stay close to the rest of the group. Once a pair links, they are then considered to be a single vehicle. After each pair is linked, the process repeats until there is only one vehicle left. The paper contains simulation results for a system of 16 vehicles.

  20. A novel time series link prediction method: Learning automata approach

    Science.gov (United States)

    Moradabadi, Behnaz; Meybodi, Mohammad Reza

    2017-09-01

    Link prediction is a main social network challenge that uses the network structure to predict future links. The common link prediction approaches to predict hidden links use a static graph representation where a snapshot of the network is analyzed to find hidden or future links. For example, similarity metric based link predictions are a common traditional approach that calculates the similarity metric for each non-connected link and sort the links based on their similarity metrics and label the links with higher similarity scores as the future links. Because people activities in social networks are dynamic and uncertainty, and the structure of the networks changes over time, using deterministic graphs for modeling and analysis of the social network may not be appropriate. In the time-series link prediction problem, the time series link occurrences are used to predict the future links In this paper, we propose a new time series link prediction based on learning automata. In the proposed algorithm for each link that must be predicted there is one learning automaton and each learning automaton tries to predict the existence or non-existence of the corresponding link. To predict the link occurrence in time T, there is a chain consists of stages 1 through T - 1 and the learning automaton passes from these stages to learn the existence or non-existence of the corresponding link. Our preliminary link prediction experiments with co-authorship and email networks have provided satisfactory results when time series link occurrences are considered.

  1. Publishing Data on Physical Samples Using the GeoLink Ontology and Linked Data Platforms

    Science.gov (United States)

    Ji, P.; Arko, R. A.; Lehnert, K. A.; Song, L.; Carter, M. R.; Hsu, L.

    2015-12-01

    Interdisciplinary Earth Data Alliance (IEDA), one of partners in EarthCube GeoLink project, seeks to explore the extent to which the use of GeoLink reusable Ontology Design Patterns (ODPs) and linked data platforms in IEDA data infrastructure can make research data more easily accessible and valuable. Linked data for the System for Earth Sample Registration (SESAR) is the first effort of IEDA to show how linked data enhance the presentation of IEDA data system architecture. SESAR Linked Data maps each table and column in SESAR database to RDF class and property based on GeoLink view, which build on the top of GeoLink ODPs. Then, uses D2RQ dumping the contents of SESAR database into RDF triples on the basis of mapping results. And, the dumped RDF triples is loaded into GRAPHDB, an RDF graph database, as permanent data in the form of atomic facts expressed as subjects, predicates and objects which provide support for semantic interoperability between IEDA and other GeoLink partners. Finally, an integrated browsing and searching interface build on Callimachus, a highly scalable platform for publishing linked data, is introduced to make sense of data stored in triplestore. Drill down and through features are built in the interface to help users locating content efficiently. The drill down feature enables users to explore beyond the summary information in the instance list of a specific class and into the detail from the specific instance page. The drill through feature enables users to jump from one instance to another one by simply clicking the link of the latter nested in the former region. Additionally, OpenLayers map is embedded into the interface to enhance the attractiveness of the presentation of instance which has geospatial information. Furthermore, by linking instances in the SESAR datasets to matching or corresponding instances in external sets, the presentation has been enriched with additional information about related classes like person, cruise, etc.

  2. Age differences in search of web pages: the effects of link size, link number, and clutter.

    Science.gov (United States)

    Grahame, Michael; Laberge, Jason; Scialfa, Charles T

    2004-01-01

    Reaction time, eye movements, and errors were measured during visual search of Web pages to determine age-related differences in performance as a function of link size, link number, link location, and clutter. Participants (15 young adults, M = 23 years; 14 older adults, M = 57 years) searched Web pages for target links that varied from trial to trial. During one half of the trials, links were enlarged from 10-point to 12-point font. Target location was distributed among the left, center, and bottom portions of the screen. Clutter was manipulated according to the percentage of used space, including graphics and text, and the number of potentially distracting nontarget links was varied. Increased link size improved performance, whereas increased clutter and links hampered search, especially for older adults. Results also showed that links located in the left region of the page were found most easily. Actual or potential applications of this research include Web site design to increase usability, particularly for older adults.

  3. A generalized theory of preferential linking

    Science.gov (United States)

    Hu, Haibo; Guo, Jinli; Liu, Xuan; Wang, Xiaofan

    2014-12-01

    There are diverse mechanisms driving the evolution of social networks. A key open question dealing with understanding their evolution is: How do various preferential linking mechanisms produce networks with different features? In this paper we first empirically study preferential linking phenomena in an evolving online social network, find and validate the linear preference. We propose an analyzable model which captures the real growth process of the network and reveals the underlying mechanism dominating its evolution. Furthermore based on preferential linking we propose a generalized model reproducing the evolution of online social networks, and present unified analytical results describing network characteristics for 27 preference scenarios. We study the mathematical structure of degree distributions and find that within the framework of preferential linking analytical degree distributions can only be the combinations of finite kinds of functions which are related to rational, logarithmic and inverse tangent functions, and extremely complex network structure will emerge even for very simple sublinear preferential linking. This work not only provides a verifiable origin for the emergence of various network characteristics in social networks, but bridges the micro individuals' behaviors and the global organization of social networks.

  4. Local Type Checking for Linked Data Consumers

    Directory of Open Access Journals (Sweden)

    Gabriel Ciobanu

    2013-07-01

    Full Text Available The Web of Linked Data is the cumulation of over a decade of work by the Web standards community in their effort to make data more Web-like. We provide an introduction to the Web of Linked Data from the perspective of a Web developer that would like to build an application using Linked Data. We identify a weakness in the development stack as being a lack of domain specific scripting languages for designing background processes that consume Linked Data. To address this weakness, we design a scripting language with a simple but appropriate type system. In our proposed architecture some data is consumed from sources outside of the control of the system and some data is held locally. Stronger type assumptions can be made about the local data than external data, hence our type system mixes static and dynamic typing. Throughout, we relate our work to the W3C recommendations that drive Linked Data, so our syntax is accessible to Web developers.

  5. Novel Link Adaptation Schemes for OFDM System

    Institute of Scientific and Technical Information of China (English)

    LEI Ming; CAI Peng; XU Yue-shan; ZHANG Ping

    2003-01-01

    Orthogonal Frequency Division Multiplexing (OFDM) is the most promising technique supporting the high data rate transmission. The combination of the link adaptation and OFDM can further increase the spectral efficiency. In this paper, we put forward two link adaptation schemes for OFDM system which have the advantages of both flexibility and practicability. Both of the two novel link adaptation schemes are based on the iterative mechanism to allocate the bit and power to subcarriers according to their channel gains and noisy levels which are assumed to be already known at the transmitter. The candidate modulation modes are determined freely before the link adaptation schemes are performed. The distinction between the two novel link adaptation schemes is that in the novel scheme A, the modulation mode is upgraded to the neighboring higher-order mode, while in the novel scheme B the modulation is upgraded to the genuine optimal mode. Therefore, the novel scheme A has the advantage of lower complexity and the novel scheme B has the advantage of higher spectral efficiency.

  6. Cross-linking chemistry of squid beak.

    Science.gov (United States)

    Miserez, Ali; Rubin, Daniel; Waite, J Herbert

    2010-12-03

    In stark contrast to most aggressive predators, Dosidicus gigas (jumbo squids) do not use minerals in their powerful mouthparts known as beaks. Their beaks instead consist of a highly sclerotized chitinous composite with incremental hydration from the tip to the base. We previously reported l-3,4-dihydroxyphenylalanine (dopa)-histidine (dopa-His) as an important covalent cross-link providing mechanical strengthening to the beak material. Here, we present a more complete characterization of the sclerotization chemistry and describe additional cross-links from D. gigas beak. All cross-links presented in this report share common building blocks, a family of di-, tri-, and tetra-histidine-catecholic adducts, that were separated by affinity chromatography and high performance liquid chromatography (HPLC) and identified by tandem mass spectroscopy and proton nuclear magnetic resonance ((1)H NMR). The data provide additional insights into the unusually high cross-link density found in mature beaks. Furthermore, we propose both a low molecular weight catechol, and peptidyl-dopa, to be sclerotization agents of squid beak. This appears to represent a new strategy for forming hard tissue in animals. The interplay between covalent cross-linking and dehydration on the graded properties of the beaks is discussed.

  7. Equipment selection heuristics for microwave fixed links

    Science.gov (United States)

    Flood, I. D.; Allen, S. M.

    2014-08-01

    Microwave fixed links use highly standardized radio equipment and, in the radio equipment standard referenced in this paper, there is a choice between exactly two radio systems when the assigner wishes to resolve a specific data rate exactly: one using a relatively lower-order modulation scheme and one a relatively higher-order scheme. Although the higher-order equipment requires less bandwidth for an isolated link, these systems radiate at higher powers and require larger protection ratios in the radio interference environment which lead to well-established trade-offs between modulation, bandwidth, equivalent isotropic radiated power, and frequency assignment criteria. Our earlier research showed that by extending the Frequency Assignment Problem to include equipment selection and using lower-order modulation equipment on selected links, we can actually reduce the overall span of frequencies required for a network frequency assignment. This work focused on the development of integer programming formulations and analyzed the exact solutions obtained. Exact solutions are impractical for real world problems; hence, here we focus on the development of heuristics for equipment selection. We can model the fixed link network as a complete graph where the vertices represent fixed link frequency assignment requests and the edges represent interference between pairs of vertices. Using a graph theoretic analysis of the interference problem, we propose heuristic techniques and discuss the relative success of our approach in this article.

  8. Why should we publish Linked Data?

    Science.gov (United States)

    Blower, Jon; Riechert, Maik; Koubarakis, Manolis; Pace, Nino

    2016-04-01

    We use the Web every day to access information from all kinds of different sources. But the complexity and diversity of scientific data mean that discovering accessing and interpreting data remains a large challenge to researchers, decision-makers and other users. Different sources of useful information on data, algorithms, instruments and publications are scattered around the Web. How can we link all these things together to help users to better understand and exploit earth science data? How can we combine scientific data with other relevant data sources, when standards for describing and sharing data vary so widely between communities? "Linked Data" is a term that describes a set of standards and "best practices" for sharing data on the Web (http://www.w3.org/standards/semanticweb/data). These principles can be summarised as follows: 1. Create unique and persistent identifiers for the important "things" in a community (e.g. datasets, publications, algorithms, instruments). 2. Allow users to "look up" these identifiers on the web to find out more information about them. 3. Make this information machine-readable in a community-neutral format (such as RDF, Resource Description Framework). 4. Within this information, embed links to other things and concepts and say how these are related. 5. Optionally, provide web service interfaces to allow the user to perform sophisticated queries over this information (using a language such as SPARQL). The promise of Linked Data is that, through these techniques, data will be more discoverable, more comprehensible and more usable by different communities, not just the community that produced the data. As a result, many data providers (particularly public-sector institutions) are now publishing data in this way. However, this area is still in its infancy in terms of real-world applications. Data users need guidance and tools to help them use Linked Data. Data providers need reassurance that the investments they are making in

  9. Quantitative linking hypotheses for infant eye movements.

    Directory of Open Access Journals (Sweden)

    Daniel Yurovsky

    Full Text Available The study of cognitive development hinges, largely, on the analysis of infant looking. But analyses of eye gaze data require the adoption of linking hypotheses: assumptions about the relationship between observed eye movements and underlying cognitive processes. We develop a general framework for constructing, testing, and comparing these hypotheses, and thus for producing new insights into early cognitive development. We first introduce the general framework--applicable to any infant gaze experiment--and then demonstrate its utility by analyzing data from a set of experiments investigating the role of attentional cues in infant learning. The new analysis uncovers significantly more structure in these data, finding evidence of learning that was not found in standard analyses and showing an unexpected relationship between cue use and learning rate. Finally, we discuss general implications for the construction and testing of quantitative linking hypotheses. MATLAB code for sample linking hypotheses can be found on the first author's website.

  10. Improving personalized link prediction by hybrid diffusion

    CERN Document Server

    Liu, Jin-Hu; Zhou, Tao

    2016-01-01

    Inspired by traditional link prediction and to solve the problem of recommending friends in social networks, we introduce the personalized link prediction in this paper, in which each individual will get equal number of diversiform predictions. While the performances of many classical algorithms are not satisfactory under this framework, thus new algorithms are in urgent need. Motivated by previous researches in other fields, we generalize heat conduction process to the framework of personalized link prediction and find that this method outperforms many classical similarity-based algorithms, especially in the performance of diversity. In addition, we demonstrate that adding one ground node who is supposed to connect all the nodes in the system will greatly benefit the performance of heat conduction. Finally, better hybrid algorithms composed of local random walk and heat conduction have been proposed. Numerical results show that the hybrid algorithms can outperform other algorithms simultaneously in all four ...

  11. Predicting missing links via significant paths

    CERN Document Server

    Zhu, Xuzhen; Cai, Shimin; Huang, Junming; Zhou, Tao

    2014-01-01

    Link prediction plays an important role in understanding intrinsic evolving mechanisms of networks. With the belief that the likelihood of the existence of a link between two nodes is strongly related with their similarity, many methods have been proposed to calculate node similarity based on node attributes and/or topological structures. Among a large variety of methods that take into account paths connecting the target pair of nodes, most of which neglect the heterogeneity of those paths. Our hypothesis is that a path consisting of small-degree nodes provides a strong evidence of similarity between two ends, accordingly, we propose a so-called sig- nificant path index in this Letter to leverage intermediate nodes' degrees in similarity calculation. Empirical experiments on twelve disparate real networks demonstrate that the proposed index outperforms the mainstream link prediction baselines.

  12. Discovering and Mining Links for Protein Databases

    Directory of Open Access Journals (Sweden)

    A.Immaculate Mercy

    2014-01-01

    Full Text Available This work introduces a link analysis procedure for discovering relationships in a protein database or a relational database generalizing simple correspondence analysis. It is based on extracting the links to the rela ted protein database and malfunctioned protein database. The datasets are trained in order to find out missing interactions and the sequences related to them. Further the analysis of links proceeds by performing a random walk defining a Markov chain. The e lements of interest are analysed through stochastic complementation which gives a reduced Markov chain. This reduced map is then analysed by projecting the elements of interest through Principal component analysis. Several Protein datasets are analysed using the proposed methodology, showing the usefulness of the technique for extracting relationships in relational databases or graphs.

  13. Discovering and Mining Links for Protein Databases

    Directory of Open Access Journals (Sweden)

    A. Immaculate Mercy

    2015-10-01

    Full Text Available link analysis procedure for discovering relationships in a protein database or a relational database generalizing simple correspondence analysis. It is based on extracting the links to the related protein database and malfunctioned protein database. The datasets are trained in order to find out missing interactions and the sequences related to them. Further the analysis of links proceeds by performing a random walk defining a Markov chain. The elements of interest are analysed through stochastic complementation which gives a reduced Markov chain. This reduced map is then analysed by projecting the elements of interest through Principal component analysis. Several Protein datasets are analysed using the proposed methodology, showing the usefulness of the technique for extracting relationships in relational databases or graphs.

  14. Service Migration Protocol for NFC Links

    DEFF Research Database (Denmark)

    Nickelsen, Anders; Schwefel, Hans-Peter; Martin, Miquel

    2010-01-01

    of use while preserving state. This paper focuses on the scenario of migration between two devices in which the actual migration procedure is executed over near-field communication (NFC) ad-hoc links. The NFC link is interesting as it gives the user the perception of trust and enables service continuity...... in cases where mid- or long-range wireless connectivity is unavailable. Based on an experimental performance analysis of a specific NFC platform, the paper presents a migration orchestration protocol with low overhead and low delays to be used with NFC links. Experimental results allow to conclude...... on the sizes of application state that can be expected to be feasible for such ad-hoc NFC migration....

  15. Editorial: Link Spam and Search Engines

    Directory of Open Access Journals (Sweden)

    Alireza Noruzi

    2006-03-01

    Full Text Available The growing number of blogs has caused problems for search engines, problems such as the highly frequent blog spam. Spammers use blogs to promote their websites. Spammers are trying to win the attention of search engines, not of bloggers or their readers. Link spam dishonestly and deliberately manipulates link-based ranking algorithms of search engines like Google's PageRank to increase the rank of a web site or page so that it is placed as close to the top of search results as possible. A link-based ranking algorithm gives a higher ranking to a site that has many backlinks, especially from highly-ranked sites/pages.

  16. Mining Electronic Health Records using Linked Data.

    Science.gov (United States)

    Odgers, David J; Dumontier, Michel

    2015-01-01

    Meaningful Use guidelines have pushed the United States Healthcare System to adopt electronic health record systems (EHRs) at an unprecedented rate. Hospitals and medical centers are providing access to clinical data via clinical data warehouses such as i2b2, or Stanford's STRIDE database. In order to realize the potential of using these data for translational research, clinical data warehouses must be interoperable with standardized health terminologies, biomedical ontologies, and growing networks of Linked Open Data such as Bio2RDF. Applying the principles of Linked Data, we transformed a de-identified version of the STRIDE into a semantic clinical data warehouse containing visits, labs, diagnoses, prescriptions, and annotated clinical notes. We demonstrate the utility of this system though basic cohort selection, phenotypic profiling, and identification of disease genes. This work is significant in that it demonstrates the feasibility of using semantic web technologies to directly exploit existing biomedical ontologies and Linked Open Data.

  17. Urban rainfall estimation employing commercial microwave links

    Science.gov (United States)

    Overeem, Aart; Leijnse, Hidde; Uijlenhoet, Remko; ten Veldhuis, Marie-claire

    2015-04-01

    Urban areas often lack rainfall information. To increase the number of rainfall observations in cities, microwave links from operational cellular telecommunication networks may be employed. Although this new potential source of rainfall information has been shown to be promising, its quality needs to be demonstrated more extensively. In the Rain Sense kickstart project of the Amsterdam Institute for Advanced Metropolitan Solutions (AMS), sensors and citizens are preparing Amsterdam for future weather. Part of this project is rainfall estimation using new measurement techniques. Innovative sensing techniques will be utilized such as rainfall estimation from microwave links, umbrellas for weather sensing, low-cost sensors at lamp posts and in drainage pipes for water level observation. These will be combined with information provided by citizens in an active way through smartphone apps and in a passive way through social media posts (Twitter, Flickr etc.). Sensor information will be integrated, visualized and made accessible to citizens to help raise citizen awareness of urban water management challenges and promote resilience by providing information on how citizens can contribute in addressing these. Moreover, citizens and businesses can benefit from reliable weather information in planning their social and commercial activities. In the end city-wide high-resolution rainfall maps will be derived, blending rainfall information from microwave links and weather radars. This information will be used for urban water management. This presentation focuses on rainfall estimation from commercial microwave links. Received signal levels from tens of microwave links within the Amsterdam region (roughly 1 million inhabitants) in the Netherlands are utilized to estimate rainfall with high spatial and temporal resolution. Rainfall maps will be presented and compared to a gauge-adjusted radar rainfall data set. Rainfall time series from gauge(s), radars and links will be compared.

  18. LinkMF: Collaborative Filtering Recommendation Algorithm with Linked Data%LinkMF:结合Linked Data的协同过滤推荐算法

    Institute of Scientific and Technical Information of China (English)

    黄山山; 马军; 郭磊; 王帅强

    2016-01-01

    协同过滤(CF)是推荐系统中应用最为广泛的推荐算法之一,然而数据稀疏性和冷启动问题是协同过滤方法的两个主要挑战.由于Linked Data整合了关于实体的丰富且结构化的特征,可以作为额外的信息源来缓解以上两种挑战.该文中我们首次提出了结合Linked Data改进CF推荐算法,基于矩阵分解提出了一种新的CF模型——LinkMF,在保证推荐准确度的基础上利用Linked Data缓解数据稀疏性和冷启动问题.首先,我们从Linked Data中抽取项目的特征表示并为项目建模;然后提出新的相似度度量方法计算项目相似度;最后利用项目相似度约束和指导MF分解过程产生推荐.在MovielLens和YAGO标准数据集上的大量实验结果表明,LinkMF优于现有的一些CF方法,特别在缓解数据稀疏性和冷启动问题上取得很好地效果.

  19. Genetics Home Reference: X-linked dilated cardiomyopathy

    Science.gov (United States)

    ... Conditions X-linked dilated cardiomyopathy X-linked dilated cardiomyopathy Printable PDF Open All Close All Enable Javascript ... the expand/collapse boxes. Description X-linked dilated cardiomyopathy is a form of heart disease. Dilated cardiomyopathy ...

  20. Genetics Home Reference: X-linked sideroblastic anemia and ataxia

    Science.gov (United States)

    ... linked sideroblastic anemia and ataxia X-linked sideroblastic anemia and ataxia Printable PDF Open All Close All ... the expand/collapse boxes. Description X-linked sideroblastic anemia and ataxia is a rare condition characterized by ...

  1. Genetics Home Reference: X-linked sideroblastic anemia

    Science.gov (United States)

    ... Conditions X-linked sideroblastic anemia X-linked sideroblastic anemia Printable PDF Open All Close All Enable Javascript ... the expand/collapse boxes. Description X-linked sideroblastic anemia is an inherited disorder that prevents developing red ...

  2. Genetics Home Reference: X-linked adrenal hypoplasia congenita

    Science.gov (United States)

    ... X-linked adrenal hypoplasia congenita X-linked adrenal hypoplasia congenita Enable Javascript to view the expand/collapse ... Open All Close All Description X-linked adrenal hypoplasia congenita is a disorder that mainly affects males. ...

  3. Link prediction based on path entropy

    CERN Document Server

    Xu, Zhongqi; Yang, Jian

    2015-01-01

    Information theory has been taken as a prospective tool for quantifying the complexity of complex networks. In this paper, we first study the information entropy or uncertainty of a path using the information theory. Then we apply the path entropy to the link prediction problem in real-world networks. Specifically, we propose a new similarity index, namely Path Entropy (PE) index, which considers the information entropies of shortest paths between node pairs with penalization to long paths. Empirical experiments demonstrate that PE index outperforms the mainstream link predictors.

  4. Enterprise Linked Data as Core Business Infrastructure

    Science.gov (United States)

    Harris, Steve; Ilube, Tom; Tuffield, Mischa

    This chapter describes Garlik's motivation, interest, and experiences of using Linked Data technologies in its online services. It describes the methodologies and approaches that were taken in order to deploy online services to hundreds of thousands of users, and describes the trade-offs inherent in our choice of these technologies for our production systems. In order to help illustrate and aid the arguments for the adoption of SemanticWeb technologies this chapter will focus on two of our customer facing products, DataPatrol, a consumer-centric personal information protection product, and QDOS a Linked Data service that is used to measure peoples' online activity

  5. The political dimension of "linking social capital"

    DEFF Research Database (Denmark)

    Rubin, Olivier

    2016-01-01

    . Through an analysis of existing analytical practices, the article concludes that linking social capital is often subordinated to the two related social capital concepts of bonding and bridging, and that linking social capital is often exclusively defined and operationalized based on expressions...... of organizational trust and participation. The article proposes a recalibration to encompass the political dynamics, and political survival theory is recommended as a way to address the hitherto underexplored governance dimension. Rather than using trust as the analytical pivot, this analytical entry point may...

  6. Microwave line of sight link engineering

    CERN Document Server

    Angueira, Pablo

    2012-01-01

    A comprehensive guide to the design, implementation, and operation of line of sight microwave link systems The microwave Line of Sight (LOS) transport network of any cellular operator requires at least as much planning effort as the cellular infrastructure itself. The knowledge behind this design has been kept private by most companies and has not been easy to find. Microwave Line of Sight Link Engineering solves this dilemma. It provides the latest revisions to ITU reports and recommendations, which are not only key to successful design but have changed dramatically in

  7. Link prediction via generalized coupled tensor factorisation

    DEFF Research Database (Denmark)

    Ermiş, Beyza; Evrim, Acar Ataman; Taylan Cemgil, A.

    2012-01-01

    and higher-order tensors. We propose to use an approach based on probabilistic interpretation of tensor factorisation models, i.e., Generalised Coupled Tensor Factorisation, which can simultaneously fit a large class of tensor models to higher-order tensors/matrices with com- mon latent factors using...... different loss functions. Numerical experiments demonstrate that joint analysis of data from multiple sources via coupled factorisation improves the link prediction performance and the selection of right loss function and tensor model is crucial for accurately predicting missing links....

  8. HTS 20 M 600 a link assembled

    CERN Document Server

    Ballarino, A

    2013-01-01

    The final deliverable of the EuCARD Task 7.5 activity is a 20 m long Superconducting Link made of HTS (High Temperature Superconducting) cables of the type and in quantity as required for the powering of the LHC superconducting circuits fed from LHC P7 (50 cables rated at 600 A). Following an intense R&D activity, which included the study of novel concepts of cables made from HTS tape conductor and the development and test of prototype units, the final deliverable was successfully assembled at CERN in May 2013. This document reports on the activity that culminated with the assembly of the 20 m long HTS Superconducting Link.

  9. Combinatorics of Link Diagrams and Volume

    OpenAIRE

    Giambrone, Adam

    2013-01-01

    We show that the volumes of certain hyperbolic A-adequate links can be bounded (above and) below in terms of two diagrammatic quantities: the twist number and the number of certain alternating tangles in an A-adequate diagram. We then restrict our attention to plat closures of certain braids, a rich family of links whose volumes can be bounded in terms of the twist number alone. Furthermore, in the absence of special tangles, our volume bounds can be expressed in terms of a single stable coef...

  10. FormLink/FeynCalcFormLink : Embedding FORM in Mathematica and FeynCalc

    CERN Document Server

    Feng, Feng

    2012-01-01

    FORM, a symbolic manipulation system, has been widely used in a lot of calculations for High Energy Physics due to its high performance and fficient design. Mathematica, another computational software program, has also widely been used, but more for reasons of generality and user-friendliness than for speed. Especially calculations involving tensors and noncommutative operations like calculating Dirac traces can be rather slow in Mathematica, compared to FORM. In this article we describe FormLink and FeynCalcFormLink, two Mathematica packages to link Mathematica and FeynCalc with FORM. FormLink can be used without FeynCalc and FeynCalcFormLink, which is an extension loading FormLink and FeynCalc automatically. With these two packages the impressive speed and other special features of FORM get embedded into the generality of Mathematica and FeynCalc in a simple manner. FeynCalcFormLink provides a FORM-based turbo for FeynCalc, making it much more efficient. FormLink turns Mathematica into an editor and code or...

  11. Use of link to mammography screening information and link sharing strategies

    DEFF Research Database (Denmark)

    Mukai, Thomas; Bro, Flemming; Olesen, Frede

    2011-01-01

    Introduction: The Internet is increasingly being used for disseminating knowledge in health care. Often this is done through a ‘Uniform Resource Locator’ (URL), better known as a link. There are three ways of sharing a link: verbally, in print or electronically. Furthermore, timing and exposure...

  12. Inheritance of most X-linked traits is not dominant or recessive, just X-linked

    NARCIS (Netherlands)

    Dobyns, WB; Filauro, A; Tomson, BN; Chan, AS; Ho, AW; Ting, NT; Oosterwijk, JC; Ober, C

    2004-01-01

    The existence of X-linked disorders in humans has been recognized for many centuries, based on lessons in religious texts and observations of specific human families (e.g., color blindness or Daltonism). Our modern concepts of Mendelian (including X-linked) inheritance originated just after the turn

  13. Inheritance of most X-linked traits is not dominant or recessive, just X-linked

    NARCIS (Netherlands)

    Dobyns, WB; Filauro, A; Tomson, BN; Chan, AS; Ho, AW; Ting, NT; Oosterwijk, JC; Ober, C

    2004-01-01

    The existence of X-linked disorders in humans has been recognized for many centuries, based on lessons in religious texts and observations of specific human families (e.g., color blindness or Daltonism). Our modern concepts of Mendelian (including X-linked) inheritance originated just after the turn

  14. W-Band Real-Time Transmission Utilizing a Reconfigurable RAU for NG-PON Networks

    DEFF Research Database (Denmark)

    Chorchos, Łukasz; Turkiewicz, Jarosław P.; Rommel, Simon;

    2016-01-01

    In this article, we propose and test a reconfigurable Remote Access Unit (RAU) to interface optical and W-band wireless communication links (75–110 GHz), utilizing optical heterodyne signal upconversion. The RAU is composed of a tunable local oscillator, narrow optical filter and a control unit....... The RAU can be software-reconfigured to select a specific dense wavelength division multiplexed (DWDM) channel. Real-time tests with 100 GHz spaced DWDM signals have been performed. Real-time 2.5 Gbit/s error free radio transmission in the 75 GHz to 95 GHz range of the W-band was achieved after 15 km...

  15. Linked data for libraries, archives and museums how to clean, link and publish your metadata

    CERN Document Server

    Hooland, Seth van

    2014-01-01

    This highly practical handbook teaches you how to unlock the value of your existing metadata through cleaning, reconciliation, enrichment and linking and how to streamline the process of new metadata creation. Libraries, archives and museums are facing up to the challenge of providing access to fast growing collections whilst managing cuts to budgets. Key to this is the creation, linking and publishing of good quality metadata as Linked Data that will allow their collections to be discovered, accessed and disseminated in a sustainable manner. This highly practical handbook teaches you how to unlock the value of your existing metadata through cleaning, reconciliation, enrichment and linking and how to streamline the process of new metadata creation. Metadata experts Seth van Hooland and Ruben Verborgh introduce the key concepts of metadata standards and Linked Data and how they can be practically applied to existing metadata, giving readers the tools and understanding to achieve maximum results with limited re...

  16. Link Margin Optimization of Free Space Optical Link under the Impact of Varying Meteorological Conditions

    Directory of Open Access Journals (Sweden)

    Amandeep Kaur Virk

    2012-03-01

    Full Text Available FSO is a free space optical technology synonymous to optical wireless communication and often called as openair photonics or infrared broadband. In free space optical communication, data is transmitted from point-to-point and multipoint using low-powered infrared lasers. FSO allows transmitting and receiving of voice, video, and data information. High speed and license free installation are the key features of this technology. The performance of FSO link is significantly affected by meteorological conditions viz. rain, scintillation, geometric attenuation and snow etc. In this paper we have formulated the link margin equation for the performanceevaluation of FSO link under varying meteorological conditions. Performance of the considered FSO link has been optimized on the basis of signal wavelength, link length and launched power level.

  17. Mechanically linked polyrotaxanes : A stepwise approach

    NARCIS (Netherlands)

    Werts, MPL; van den Boogaard, M; Tsivgoulis, GM; Hadziioannou, G

    2003-01-01

    A new synthetic approach for the preparation of mechanically linked polyrotaxanes was developed. Two variations of rotaxane monomers were synthesized, based on diphenylmethane and tetraphenylmethane blocking groups. Both rotaxanes bear a protected phenol functionality in the dumbbell-shaped part and

  18. Cross-linked structure of network evolution

    Science.gov (United States)

    Bassett, Danielle S.; Wymbs, Nicholas F.; Porter, Mason A.; Mucha, Peter J.; Grafton, Scott T.

    2014-03-01

    We study the temporal co-variation of network co-evolution via the cross-link structure of networks, for which we take advantage of the formalism of hypergraphs to map cross-link structures back to network nodes. We investigate two sets of temporal network data in detail. In a network of coupled nonlinear oscillators, hyperedges that consist of network edges with temporally co-varying weights uncover the driving co-evolution patterns of edge weight dynamics both within and between oscillator communities. In the human brain, networks that represent temporal changes in brain activity during learning exhibit early co-evolution that then settles down with practice. Subsequent decreases in hyperedge size are consistent with emergence of an autonomous subgraph whose dynamics no longer depends on other parts of the network. Our results on real and synthetic networks give a poignant demonstration of the ability of cross-link structure to uncover unexpected co-evolution attributes in both real and synthetic dynamical systems. This, in turn, illustrates the utility of analyzing cross-links for investigating the structure of temporal networks.

  19. Gut Microbes Linked to Rheumatoid Arthritis

    Science.gov (United States)

    ... of microorganisms that live in and on the human body. These microbes outnumber the body’s cells by 10 ... this is indeed the case.” — by Carol Torgan, Ph.D. Related Links Feeling Out of ... Autoimmune Diseases Rheumatoid Arthritis References: Expansion ...

  20. Improving personalized link prediction by hybrid diffusion

    Science.gov (United States)

    Liu, Jin-Hu; Zhu, Yu-Xiao; Zhou, Tao

    2016-04-01

    Inspired by traditional link prediction and to solve the problem of recommending friends in social networks, we introduce the personalized link prediction in this paper, in which each individual will get equal number of diversiform predictions. While the performances of many classical algorithms are not satisfactory under this framework, thus new algorithms are in urgent need. Motivated by previous researches in other fields, we generalize heat conduction process to the framework of personalized link prediction and find that this method outperforms many classical similarity-based algorithms, especially in the performance of diversity. In addition, we demonstrate that adding one ground node that is supposed to connect all the nodes in the system will greatly benefit the performance of heat conduction. Finally, better hybrid algorithms composed of local random walk and heat conduction have been proposed. Numerical results show that the hybrid algorithms can outperform other algorithms simultaneously in all four adopted metrics: AUC, precision, recall and hamming distance. In a word, this work may shed some light on the in-depth understanding of the effect of physical processes in personalized link prediction.

  1. Using Linked Data in Learning Analytics

    NARCIS (Netherlands)

    d'Aquin, Mathieu; Dietze, Stefan; Herder, Eelco; Drachsler, Hendrik; Taibi, David

    2014-01-01

    Learning Analytics has a lot to do with data, and the way to make sense of raw data in terms of the learner’s experience, behaviour and knowledge. In this article, we argue about the need for a closer relationship between the field of Learning Analytics and the one of Linked Data, which in our view

  2. Mapping markers linked to porcine salmonellosis susceptibility

    NARCIS (Netherlands)

    Galina-Pantoja, L.; Siggens, K.; Schriek, M.G.; Heuven, H.C.M.

    2009-01-01

    Anim Genet. 2009 Jun 3. [Epub ahead of print] Mapping markers linked to porcine salmonellosis susceptibility. Galina-Pantoja L, Siggens K, van Schriek MG, Heuven HC. PIC/Genus, 100 Bluegrass Commons Blvd, Hendersonville, TN 37075, USA. The goal of this study was to identify pig chromosomal regions a

  3. Sharp Connection: Linking Competitive Intelligence and Intranets

    NARCIS (Netherlands)

    Hendriks, P.H.J.; Jacobs, W.H.

    2003-01-01

    Assessing the value of ICT to support Competitive Intelligence presumes an understanding of the relationship between the two. The chapter argues that starting from either the ICT or CI side to this relationship and linking to the other, as most studies do, cannot secure a fully adequate conception o

  4. Auditing dynamic links to online information resources.

    Science.gov (United States)

    Li, Jianhua; Cimino, James J

    2007-10-11

    The Columbia University Infobutton Manager (IM) is a system that provides dynamically generated, context-specific links between clinical information systems and online information resources. The resources range from local documents, to commercially available document sets and search engines. The links provided by the IM can be reliably created, but there is no guarantee that they will function reliably, since the resources to which they point are subject to unannounced changes and failures. We have developed a set of tools to audit the links periodically to determine if the resources are available and if the IM has sufficient information to generate all the links needed by its users. These tools have been in use since February, 2006 and have provided timely warnings on many occasions. These warnings have allowed us to correct problems with resource access before they became apparent to our users and often before the resource maintainers were aware of the problems. The tools have thus helped us provide clinicians with a dependable level of service.

  5. Link prediction in multiplex online social networks.

    Science.gov (United States)

    Jalili, Mahdi; Orouskhani, Yasin; Asgari, Milad; Alipourfard, Nazanin; Perc, Matjaž

    2017-02-01

    Online social networks play a major role in modern societies, and they have shaped the way social relationships evolve. Link prediction in social networks has many potential applications such as recommending new items to users, friendship suggestion and discovering spurious connections. Many real social networks evolve the connections in multiple layers (e.g. multiple social networking platforms). In this article, we study the link prediction problem in multiplex networks. As an example, we consider a multiplex network of Twitter (as a microblogging service) and Foursquare (as a location-based social network). We consider social networks of the same users in these two platforms and develop a meta-path-based algorithm for predicting the links. The connectivity information of the two layers is used to predict the links in Foursquare network. Three classical classifiers (naive Bayes, support vector machines (SVM) and K-nearest neighbour) are used for the classification task. Although the networks are not highly correlated in the layers, our experiments show that including the cross-layer information significantly improves the prediction performance. The SVM classifier results in the best performance with an average accuracy of 89%.

  6. Cross-linked structure of network evolution

    Energy Technology Data Exchange (ETDEWEB)

    Bassett, Danielle S., E-mail: dsb@seas.upenn.edu [Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Department of Physics, University of California, Santa Barbara, California 93106 (United States); Sage Center for the Study of the Mind, University of California, Santa Barbara, California 93106 (United States); Wymbs, Nicholas F.; Grafton, Scott T. [Department of Psychology and UCSB Brain Imaging Center, University of California, Santa Barbara, California 93106 (United States); Porter, Mason A. [Oxford Centre for Industrial and Applied Mathematics, Mathematical Institute, University of Oxford, Oxford OX2 6GG (United Kingdom); CABDyN Complexity Centre, University of Oxford, Oxford, OX1 1HP (United Kingdom); Mucha, Peter J. [Carolina Center for Interdisciplinary Applied Mathematics, Department of Mathematics, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Department of Applied Physical Sciences, University of North Carolina, Chapel Hill, North Carolina 27599 (United States)

    2014-03-15

    We study the temporal co-variation of network co-evolution via the cross-link structure of networks, for which we take advantage of the formalism of hypergraphs to map cross-link structures back to network nodes. We investigate two sets of temporal network data in detail. In a network of coupled nonlinear oscillators, hyperedges that consist of network edges with temporally co-varying weights uncover the driving co-evolution patterns of edge weight dynamics both within and between oscillator communities. In the human brain, networks that represent temporal changes in brain activity during learning exhibit early co-evolution that then settles down with practice. Subsequent decreases in hyperedge size are consistent with emergence of an autonomous subgraph whose dynamics no longer depends on other parts of the network. Our results on real and synthetic networks give a poignant demonstration of the ability of cross-link structure to uncover unexpected co-evolution attributes in both real and synthetic dynamical systems. This, in turn, illustrates the utility of analyzing cross-links for investigating the structure of temporal networks.

  7. Testing a missing spectral link in turbulence

    NARCIS (Netherlands)

    Kellay, H.; Tran, A.T.; Goldburg, W.; Goldenfeld, N.; Gioia, G.; Chakraborty, P.

    2012-01-01

    Although the cardinal attribute of turbulence is the velocity fluctuations, these fluctuations have been ignored in theories of the frictional drag of turbulent flows. Our goal is to test a new theory that links the frictional drag to the spectral exponent , a property of the velocity fluctuations i

  8. Linking online news and social media

    NARCIS (Netherlands)

    Tsagkias, M.; de Rijke, M.; Weerkamp, W.

    2011-01-01

    Much of what is discussed in social media is inspired by events in the news and, vice versa, social media provide us with a handle on the impact of news events. We address the following linking task: given a news article, find social media utterances that implicitly reference it. We follow a three-s

  9. Link Enhancer for Vehicular Wireless ATM Communications

    CERN Document Server

    Arun Kumar, S P; Kumar, Amrendra

    2008-01-01

    Majority of the applications used in defense are voice, video and data oriented and has strict QoS requirements. One of the technologies that enabled this is Asynchronous Transfer Mode (ATM) networking. Traditional ATM networks are wired networks. But Tactical networks are meant to be mobile and this necessitates the use of radio relays for Vehicle-to-Infrastructure (V2I) and Vehicle-to-Vehicle (V2V) communications. ATM networks assume a physical link layer BER of 10^-9 or better because of the availability of reliable media like optical fiber links. But this assumption is no longer valid when ATM switches are connected through radio relay where error rates are in the rage of 10^-3. This paper presents the architecture of a Link Enhancer meant to improve the Bit Error Rate of the Wireless links used for V2I and V2V communications from 1 in 10^4 to 1 in 10^8

  10. Analysis Links Zoning Policies and Disparities

    Science.gov (United States)

    Shah, Nirvi

    2012-01-01

    Location, location, location. This mantra of real estate agents and their clients alike is now the target of a new report from the Brookings Institution linking housing prices and zoning practices to effectively depriving low-income students of high-quality schools. Using test scores from schools in the 100 largest metropolitan areas in the…

  11. The Missing Link: Research on Teacher Education

    Science.gov (United States)

    Wiens, Peter D.

    2012-01-01

    Teacher education has recently come under attack for its perceived lack of efficacy in preparing teachers for classroom duty. A lack of comprehensive research in teacher education makes it difficult to understand the effects of teacher education programs on student learning. There is a missing link between what happens in teacher education…

  12. Eponyms in dermatology literature linked to Otorhinolaryngology

    Directory of Open Access Journals (Sweden)

    Ahed Aqeel

    2017-01-01

    Full Text Available In some disorders, there are symptoms or signs shared by dermatology and ears, nose and throat (ENT specialty. It is also known that there are eponyms in dermatology and ENT. The aim in this short communication is to shed some lights on the eponyms in dermatology literature linked to ENT.

  13. Inter-satellite links for cubesats

    NARCIS (Netherlands)

    Budianu, A.; Castro, T.J.W.; Meijerink, Arjan; Bentum, Marinus Jan

    2013-01-01

    Realizing inter-satellite links is a must for ensuring the success of cubesat swarm missions. Nevertheless, it has hardly been considered until now. The communication systems for cubesats have to deal with a few peculiar demands regarding consumed power, geometry and throughput. Depending on the typ

  14. Self-assembly of knots and links

    Science.gov (United States)

    Orlandini, Enzo; Polles, Guido; Marenduzzo, Davide; Micheletti, Cristian

    2017-03-01

    Guiding the self-assembly of identical building blocks towards complex three-dimensional structures with a set of desired properties is a major goal in material science, chemistry and physics. A particularly challenging problem, especially explored in synthetic chemistry, is that of self-assembling closed structures with a target topology starting by simple geometrical templates. Here we overview and revisit recent advancements, based on stochastic simulations, where the geometry of rigid helical templates with functionalised sticky ends has been designed for self-assembling efficiently and reproducibly into a wide range of three-dimensional closed structures. Notably, these include non trivial topologies of links and knots, including the 819 knot that we had predicted to be highly encodable and that has only recently been obtained experimentally. By appropriately tuning the parameters that define the template shape, we show that, for fixed concentration of templates, the assembly process can be directed towards the formation of specific knotted and linked structures such as the trefoils, pentafoil knots, Hopf and Solomon links. More exotic and unexpected knots and links are also found. Our results should be relevant to the design of new protocols that can both increase and broaden the population of synthetise molecular knots and catenanes.

  15. The missing link between values and behaviour

    DEFF Research Database (Denmark)

    Brunsø, Karen

    For a long time human values have been perceived as abstrat cognitions representing desired goals or end-states which motivate humnan behaviour. A number of studies have tried to explore the link between values and behaviour, but often different constructs are included as intermediate links betwe...... and lifestyle and behaviour. Based on this appraoch we collected data covering values, lifestyle and behaviour, and estimated the cogntiive hierarchy from values to lifestyle to behaviour by structural equation models.......For a long time human values have been perceived as abstrat cognitions representing desired goals or end-states which motivate humnan behaviour. A number of studies have tried to explore the link between values and behaviour, but often different constructs are included as intermediate links between...... values and specific behaviour, since values may be too abstract to influence behaviour directly. We propose the concept of lifestyle as a mediator between values and behaviour, and present our approach to lifestyle based on principles from cognitive psychology, where we distinguish between values...

  16. Extracting Macroscopic Information from Web Links.

    Science.gov (United States)

    Thelwall, Mike

    2001-01-01

    Discussion of Web-based link analysis focuses on an evaluation of Ingversen's proposed external Web Impact Factor for the original use of the Web, namely the interlinking of academic research. Studies relationships between academic hyperlinks and research activities for British universities and discusses the use of search engines for Web link…

  17. A Verified Algebra for Linked Data

    Directory of Open Access Journals (Sweden)

    Ross Horne

    2011-07-01

    Full Text Available A foundation is investigated for the application of loosely structured data on the Web. This area is often referred to as Linked Data, due to the use of URIs in data to establish links. This work focuses on emerging W3C standards which specify query languages for Linked Data. The approach is to provide an abstract syntax to capture Linked Data structures and queries, which are then internalised in a process calculus. An operational semantics for the calculus specifies how queries, data and processes interact. A labelled transition system is shown to be sound with respect to the operational semantics. Bisimulation over the labelled transition system is used to verify an algebra over queries. The derived algebra is a contribution to the application domain. For instance, the algebra may be used to rewrite a query to optimise its distribution across a cluster of servers. The framework used to provide the operational semantics is powerful enough to model related calculi for the Web.

  18. Linking brain imaging signals to visual perception.

    Science.gov (United States)

    Welchman, Andrew E; Kourtzi, Zoe

    2013-11-01

    The rapid advances in brain imaging technology over the past 20 years are affording new insights into cortical processing hierarchies in the human brain. These new data provide a complementary front in seeking to understand the links between perceptual and physiological states. Here we review some of the challenges associated with incorporating brain imaging data into such "linking hypotheses," highlighting some of the considerations needed in brain imaging data acquisition and analysis. We discuss work that has sought to link human brain imaging signals to existing electrophysiological data and opened up new opportunities in studying the neural basis of complex perceptual judgments. We consider a range of approaches when using human functional magnetic resonance imaging to identify brain circuits whose activity changes in a similar manner to perceptual judgments and illustrate these approaches by discussing work that has studied the neural basis of 3D perception and perceptual learning. Finally, we describe approaches that have sought to understand the information content of brain imaging data using machine learning and work that has integrated multimodal data to overcome the limitations associated with individual brain imaging approaches. Together these approaches provide an important route in seeking to understand the links between physiological and psychological states.

  19. Linking Individual Creativity to Organizational Innovation

    Science.gov (United States)

    Litchfield, Robert C.; Ford, Cameron M.; Gentry, Richard J.

    2015-01-01

    We draw on 146 employee-co-worker-supervisor triads from 146 organizations to examine the role of individual perspective-taking and team creative environment in the association between individual creativity and organizational innovation. Adopting an interactionist perspective, we find that the link between individual creativity and organizational…

  20. Regulatory mechanisms link phenotypic plasticity to evolvability

    NARCIS (Netherlands)

    van Gestel, Jordi; Weissing, Franz J

    2016-01-01

    Organisms have a remarkable capacity to respond to environmental change. They can either respond directly, by means of phenotypic plasticity, or they can slowly adapt through evolution. Yet, how phenotypic plasticity links to evolutionary adaptability is largely unknown. Current studies of plasticit

  1. Link-space formalism for network analysis.

    Science.gov (United States)

    Smith, David M D; Lee, Chiu Fan; Onnela, Jukka-Pekka; Johnson, Neil F

    2008-03-01

    We introduce the link-space formalism for analyzing network models with degree-degree correlations. The formalism is based on a statistical description of the fraction of links l(i,j) connecting nodes of degrees i and j. To demonstrate its use, we apply the framework to some pedagogical network models, namely, random attachment, Barabási-Albert preferential attachment, and the classical Erdos and Rényi random graph. For these three models the link-space matrix can be solved analytically. We apply the formalism to a simple one-parameter growing network model whose numerical solution exemplifies the effect of degree-degree correlations for the resulting degree distribution. We also employ the formalism to derive the degree distributions of two very simple network decay models, more specifically, that of random link deletion and random node deletion. The formalism allows detailed analysis of the correlations within networks and we also employ it to derive the form of a perfectly nonassortative network for arbitrary degree distribution.

  2. Linking Estrogens, Prostatitis and Prostate Cancer

    Science.gov (United States)

    2009-03-01

    provide the first direct evidence linking phy siologic estr ogen up- regulation an d pr ostate ma lignancy via inflammation. Ellem, Stuart J...inflammation and malignancy in the prostate. The identification of estr ogen as a cause of prostatitis, as well as a fac tor in the development of

  3. Inter-satellite links for cubesats

    NARCIS (Netherlands)

    Budianu, A.; Castro, T.J.W.; Meijerink, A.; Bentum, M.J.

    2013-01-01

    Realizing inter-satellite links is a must for ensuring the success of cubesat swarm missions. Nevertheless, it has hardly been considered until now. The communication systems for cubesats have to deal with a few peculiar demands regarding consumed power, geometry and throughput. Depending on the typ

  4. Link prediction in multiplex online social networks

    Science.gov (United States)

    Jalili, Mahdi; Orouskhani, Yasin; Asgari, Milad; Alipourfard, Nazanin; Perc, Matjaž

    2017-02-01

    Online social networks play a major role in modern societies, and they have shaped the way social relationships evolve. Link prediction in social networks has many potential applications such as recommending new items to users, friendship suggestion and discovering spurious connections. Many real social networks evolve the connections in multiple layers (e.g. multiple social networking platforms). In this article, we study the link prediction problem in multiplex networks. As an example, we consider a multiplex network of Twitter (as a microblogging service) and Foursquare (as a location-based social network). We consider social networks of the same users in these two platforms and develop a meta-path-based algorithm for predicting the links. The connectivity information of the two layers is used to predict the links in Foursquare network. Three classical classifiers (naive Bayes, support vector machines (SVM) and K-nearest neighbour) are used for the classification task. Although the networks are not highly correlated in the layers, our experiments show that including the cross-layer information significantly improves the prediction performance. The SVM classifier results in the best performance with an average accuracy of 89%.

  5. One-Way Temperature Compensated Fiber Link

    Science.gov (United States)

    2011-05-01

    individual compensated links. [1] R. Wynands and S. Weyers, “Atomic Fountain Clocks,” Metrologia , vol. 42, pp. S64-S79, 2005. [2] A. D. Ludlow...3] A. Bauch, et al. ,”Comparison Between Frequency Standards oin Europe and the USA at the 10-15 Uncertainty Level,” Metrologia , vol. 43, pp.109

  6. Linking Individual Creativity to Organizational Innovation

    Science.gov (United States)

    Litchfield, Robert C.; Ford, Cameron M.; Gentry, Richard J.

    2015-01-01

    We draw on 146 employee-co-worker-supervisor triads from 146 organizations to examine the role of individual perspective-taking and team creative environment in the association between individual creativity and organizational innovation. Adopting an interactionist perspective, we find that the link between individual creativity and organizational…

  7. Using Linked Data in Learning Analytics

    NARCIS (Netherlands)

    d'Aquin, Mathieu; Dietze, Stefan; Herder, Eelco; Drachsler, Hendrik; Taibi, David

    2014-01-01

    Learning Analytics has a lot to do with data, and the way to make sense of raw data in terms of the learner’s experience, behaviour and knowledge. In this article, we argue about the need for a closer relationship between the field of Learning Analytics and the one of Linked Data, which in our view

  8. The benefits of convergence.

    Science.gov (United States)

    Chang, Gee-Kung; Cheng, Lin

    2016-03-06

    A multi-tier radio access network (RAN) combining the strength of fibre-optic and radio access technologies employing adaptive microwave photonics interfaces and radio-over-fibre (RoF) techniques is envisioned for future heterogeneous wireless communications. All-band radio spectrum from 0.1 to 100 GHz will be used to deliver wireless services with high capacity, high link speed and low latency. The multi-tier RAN will improve the cell-edge performance in an integrated heterogeneous environment enabled by fibre-wireless integration and networking for mobile fronthaul/backhaul, resource sharing and all-layer centralization of multiple standards with different frequency bands and modulation formats. In essence, this is a 'no-more-cells' architecture in which carrier aggregation among multiple frequency bands can be easily achieved with seamless handover between cells. In this way, current and future mobile network standards such as 4G and 5G can coexist with optimized and continuous cell coverage using multi-tier RoF regardless of the underlying network topology or protocol. In terms of users' experience, the future-proof approach achieves the goals of system capacity, link speed, latency and continuous heterogeneous cell coverage while overcoming the bandwidth crunch in next-generation communication networks. © 2016 The Author(s).

  9. High speed radiation tolerant data links

    Energy Technology Data Exchange (ETDEWEB)

    Brewer, Forrest [Univ. of California, Santa Barbara, CA (United States); Incandela, Joseph [Univ. of California, Santa Barbara, CA (United States)

    2016-04-01

    This project was slated to design and develop Rad-Hard IP components for 1Gb/s links and supporting hardware designs such as PLL, SER/DES, pad drivers and receivers and custom protocol hardware for the 1Gb/s channel. Also included in the proposal was a study of a hardened memory to be used as a packet buffer for channel and data concentrator components to meet the 1 Gb/s specification. Over the course of the proposal, technology change and innovation of hardware designs lead us away from the 1 Gb/s goal to contemplate much higher performance link IP which, we believed better met the goals of physics experiments. Note that CERN microelectronics had managed to create a 4.7 Gb/s link designed to drive optical fibers and containing infrastructure for connecting much lower bandwidth front-end devices. Our own work to that point had shown the possibility of constructing a link with much lower power, lower physical overhead but of equivalent performance that could be designed to integrate directly onto the front-end ASIC (ADC and data encoding) designs. Substantial overall power savings and experimental simplicity could be achieved by eliminating data transmission to data concentrators and data concentrators and related hardened buffering themselves, with conversion to optical media at a removed distance from the experiment core. We had already developed and tested Rad-Hard SER/DES components (1Gb in 130nm standard cells) and redundant Pad Drivers/Receivers (3+ Gb/s designed and measured performance), and had a viable 1Gb/s link design based on redundant a stuttered clock receiver and classical PLL, so the basic goals of the proposal had been achieved. Below, in chronological order, are the products and tools we constructed, as well as our tests and publications.

  10. DWDM系统中的光滤波技术%Optical filter technology in DWDM systems

    Institute of Scientific and Technical Information of China (English)

    刘俭辉; 鲍风雨

    2003-01-01

    @@ 密集波分复用光网络的不断演进带动节点器件技术飞速发展,光滤波技术作为其中的关键之一已不仅仅是原来狭义的复用/解复用器的概念,其涵盖的范畴越来越多,包括光分插复用(OADM)、光交叉连接(OXC)、增益平坦滤波(GFF)、色散补偿(DC)、泵浦合波器(PBC)、动态增益均衡器(DGE)、波长锁定器(Wave 1ocker)等.

  11. DWDM VSB modulation-format optical transmission: Effects of optical filtering and electrical equalization

    Science.gov (United States)

    Binh, Le Nguyen

    2008-10-01

    The transmission of 40 Gb/s wavelength multiplexed channels under vestigial single side band modulation format is transmitted over long haul optically amplified fiber systems. Bit-error-rate (BER) of 10 -12 or better can be achieved across all channels. Optical filters are designed with asymmetric roll-off bands. Simulations of the transmission performance, BER versus receiver sensitivity are demonstrated with wavelength channel spacing of 20-40 GHz. An optical filter, whose passband is 28 GHz and 20 dB cut-off band, performs best for 40 Gb/s bit rate due to optimum filtering and minimum noise contribution. Furthermore the single-sideband property of VSB format can assist linear equalization by electronic processing. The transmission performance is accurately evaluated based on the eye opening using a fast statistical method based on an equivalent Gaussian probability density distribution (pdf) which is derived from multiple peaks pdf of distorted eye diagram.

  12. Hybrid Optical Comb Filter with Multi-Port Fiber Coupler for DWDM Optical Network

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Optical comb filters based on multi-port fused fiber couplers are proposed and numerically analyzed, 3-arm MZI composed by 1×7 fiber splitter and 3×3 fiber coupler, and 2-stage cascaded FIR type MZI interleave filter.

  13. Physical Frame Time-Slot Switching- A New Switching Technique over DWDM

    Institute of Scientific and Technical Information of China (English)

    XU Deng-yuan; DOU Jun; TU Jian-ping

    2005-01-01

    A novel technique called physical frame time-slot switching (PFTS) is discussed and its technical and application aspects are analyzed. The format of the ethernet media access control (MAC)frame is borrowed in defining the physical frame for PFTS and the transmission time for the maximum size of the MAC frame is defined as a physical frame time-slot (PFT). Consequently, user data can be fed into PFTS and switched in a single layer sub-network in an asynchronous mode.

  14. Photonic crystal channel drop filter based on ring-shaped defects for DWDM systems

    Science.gov (United States)

    Dideban, Ali; Habibiyan, Hamidreza; Ghafoorifard, Hassan

    2017-03-01

    This paper presents a novel configuration of channel drop filters based on two-dimensional photonic crystal slabs in silicon-on-insulator platforms. The structure is composed of two photonic crystal line-defect waveguides as input and output ports, along with an L3 cavity with ring-shaped border holes. The effects of structural parameters and fabrication errors on resonance frequency and drop efficiency are investigated. Band structure and propagation of electromagnetic field through device are calculated by plane wave expansion and finite-difference time-domain methods. The results show that the quality factor and line-width of output signal are 5690 and 0.27 nm, respectively, indicating that the proposed filter can be properly used in dense wavelength division multiplexing systems with 0.8 nm channel spacing.

  15. DC-Link Compensation Method for Slim DC Link Drives Fed by Soft Grid

    DEFF Research Database (Denmark)

    Mathe, Laszlo; Rosendahl Andersen, Henrik; Lazar, Radu

    2010-01-01

    harmonic distortion (PWHD) of the line current are degraded, if resonance between the line impedance and the DC-link capacitance occurs. Likewise, the motor performance is affected negatively giving extra torque ripple, vibration and acoustic-noise emission. This paper proposes a novel DC-link compensation...... method, which ensures the stability of the slim DC-link on a soft grid. The proposed compensation method may be used for open- and closedloop control schemes, requiring a small overhead in the digital implementation....

  16. Weighting links based on edge centrality for community detection

    Science.gov (United States)

    Sun, Peng Gang

    2014-01-01

    Link weights have the equally important position as links in complex networks, and they are closely associated with each other for the emergence of communities. How to assign link weights to make a clear distinction between internal links of communities and external links connecting communities is of vital importance for community detection. Edge centralities provide a powerful approach for distinguishing internal links from external ones. Here, we first use edge centralities such as betweenness, information centrality and edge clustering coefficient to weight links of networks respectively to transform unweighted networks into weighted ones, and then a weighted function that both considers links and link weights is adopted on the weighted networks for community detection. We evaluate the performance of our approach on random networks as well as real-world networks. Better results are achieved on weighted networks with stronger weights of internal links of communities, and the results on unweighted networks outperform that of weighted networks with weaker weights of internal links of communities. The availability of our findings is also well-supported by the study of Granovetter that the weak links maintain the global integrity of the network while the strong links maintain the communities. Especially in the Karate club network, all the nodes are correctly classified when we weight links by edge betweenness. The results also give us a more comprehensive understanding on the correlation between links and link weights for community detection.

  17. Method of preparing cross-linked enzyme particles

    NARCIS (Netherlands)

    Mateo, C.; Van Langen, L.M.; Van Rantwijk, F.

    2004-01-01

    The invention relates to a method of preparing cross-linked enzyme particles using a cross-linking agent. According to the invention, the enzyme particles are formed and subsequently cross-linked using a cross-linking agent having at least n reactive groups where N>=3 and a molecular weight of

  18. On the classification of links up to finite type

    DEFF Research Database (Denmark)

    Habegger, Nathan; Meilhan, Jean-Baptiste

    We use an action, of 2l-component string links on l-component string links, defined by the first author and Xiao-Song Lin, to lift the indeterminacy of finite type link invariants. The set of links up to this new indeterminacy is in bijection with the orbit space of the restriction of this action...

  19. Method of preparing cross-linked enzyme particles

    NARCIS (Netherlands)

    Mateo, C.; Van Langen, L.M.; Van Rantwijk, F.

    2004-01-01

    The invention relates to a method of preparing cross-linked enzyme particles using a cross-linking agent. According to the invention, the enzyme particles are formed and subsequently cross-linked using a cross-linking agent having at least n reactive groups where N>=3 and a molecular weight of >2,00

  20. The cross linking of EPDM and NBR rubber

    Directory of Open Access Journals (Sweden)

    Samardžija-Jovanović Suzana

    2005-01-01

    Full Text Available In the process of macromolecule cross linking, the choice of type and quantity of the components and the experimental conditions are important to obtain the new cross linked materials with better mechanical and chemical characteristics. The cross linking method depends on the rubber type and structure. Intermolecular cross linking results in the formation elastomer network. The basis of the cross linking process, between ethylene propylene diene rubber (EPDM and acrylonitrile butadiene rubber (NBR, is a chemical reaction. Fillers and other additives are present in different mass ratios in the material. The exploitation properties of the cross linked materials depend on the quantity of additive in the cross linked systems.

  1. Semantic analysis of links in the musical Wikipedia

    DEFF Research Database (Denmark)

    Mølgaard, Lasse Lohilahti; Hansen, Lars Kai; Larsen, Jan

    2008-01-01

    Wikipedia has significant potential in music information retrieval research. In this work we analyze the of the link structure in the musical Wikipedia. Wikipedia links differ in certain ways from links on the Web at large. There are an over-abundance of internal links in Wikipedia, links...... are generated automatically, and they may even maliciously be used to promote certain topics. Wikipedia has been analyzed recently using methods fromWeb and text mining, however, the fact the link structure is different from the Web’s makes this approach questionable. To better understand the link structure...

  2. [Leptin: a link between obesity and osteoarthritis?].

    Science.gov (United States)

    Terlain, Bernard; Presle, Nathalie; Pottie, Pascale; Mainard, Didier; Netter, Patrick

    2006-10-01

    In addition to aging, obesity is one of the most common underlying causes of osteoarthritis (OA). Mechanical loading, together with biochemical and systemic factors linked to altered lipid metabolism, are thought to contribute to the onset of OA. It has been suggested that OA is a systemic metabolic disease associated with lipid disorders affecting joint homeostasis. These gradual changes may be due to the local effect of adipokines, and especially leptin. Indeed, their relative levels in joints differ from that found in plasma. In particular, leptin levels are increased and adiponectin and resistin levels are reduced This hypothesis is supported by--leptin overexpression in OA cartilage and its correlation with the degree of cartilage destruction,--abundant leptin synthesis by osteophytes, and--the high leptin levels found in OA joints from female patients. This link between OA and adipokines provides new leads regarding the prevention of OA and the identification of new drug targets.

  3. Dimensional enrichment of statistical linked open data

    DEFF Research Database (Denmark)

    Varga, Jovan; Vaisman, Alejandro; Romero, Oscar

    2016-01-01

    On-Line Analytical Processing (OLAP) is a data analysis technique typically used for local and well-prepared data. However, initiatives like Open Data and Open Government bring new and publicly available data on the web that are to be analyzed in the same way. The use of semantic web technologies...... for this context is especially encouraged by the Linked Data initiative. There is already a considerable amount of statistical linked open data sets published using the RDF Data Cube Vocabulary (QB) which is designed for these purposes. However, QB lacks some essential schema constructs (e.g., dimension levels......) to support OLAP. Thus, the QB4OLAP vocabulary has been proposed to extend QB with the necessary constructs and be fully compliant with OLAP. In this paper, we focus on the enrichment of an existing QB data set with QB4OLAP semantics. We first thoroughly compare the two vocabularies and outline the benefits...

  4. Stabilized Optical Fiber Links for the XFEL

    CERN Document Server

    Winter, Axel; Grawert, Felix J; Ilday, Fatih O; Kaertner, Franz X; Kim, Jung-Won; Schlarb, Holger; Schmidt, Bernhard

    2005-01-01

    The timing synchronization scheme for the European X-Ray free electron laser facility (XFEL) is based on the generation and distribution of sub-picosecond laser pulses with actively stabilized repetition rate which are used to synchronize local RF oscillators. An integral part of the scheme is the distribution of the optical pulse stream to parts of the facility via optical fiber links. The optical path length of the fiber has to be stabilized against short-term and long-term timing jitter due to environmental effects, such as temperature drifts and acoustic vibrations, to better than 10 fs for distances ranging from tens of meters to several kilometers. In this paper, we present first experimental results for signal transmission through a km-long fiber link with femtosecond stability.

  5. A neural link between generosity and happiness

    Science.gov (United States)

    Park, Soyoung Q.; Kahnt, Thorsten; Dogan, Azade; Strang, Sabrina; Fehr, Ernst; Tobler, Philippe N.

    2017-01-01

    Generous behaviour is known to increase happiness, which could thereby motivate generosity. In this study, we use functional magnetic resonance imaging and a public pledge for future generosity to investigate the brain mechanisms that link generous behaviour with increases in happiness. Participants promised to spend money over the next 4 weeks either on others (experimental group) or on themselves (control group). Here, we report that, compared to controls, participants in the experimental group make more generous choices in an independent decision-making task and show stronger increases in self-reported happiness. Generous decisions engage the temporo-parietal junction (TPJ) in the experimental more than in the control group and differentially modulate the connectivity between TPJ and ventral striatum. Importantly, striatal activity during generous decisions is directly related to changes in happiness. These results demonstrate that top–down control of striatal activity plays a fundamental role in linking commitment-induced generosity with happiness. PMID:28696410

  6. Computational intelligence, medicine and biology selected links

    CERN Document Server

    Zaitseva, Elena

    2015-01-01

    This book contains an interesting and state-of the art collection of chapters presenting several examples of attempts to developing modern tools utilizing computational intelligence in different real life problems encountered by humans. Reasoning, prediction, modeling, optimization, decision making, etc. need modern, soft and intelligent algorithms, methods and methodologies to solve, in the efficient ways, problems appearing in human activity. The contents of the book is divided into two parts. Part I, consisting of four chapters, is devoted to selected links of computational intelligence, medicine, health care and biomechanics. Several problems are considered: estimation of healthcare system reliability, classification of ultrasound thyroid images, application of fuzzy logic to measure weight status and central fatness, and deriving kinematics directly from video records. Part II, also consisting of four chapters, is devoted to selected links of computational intelligence and biology. The common denominato...

  7. Depression And The Link With Cardiovascular Disease

    Directory of Open Access Journals (Sweden)

    Arup Kumar Dhar

    2016-03-01

    Full Text Available This review provides an outline of the association between major depressive disorder (MDD and coronary heart disease (CHD. Much is known about the two individual clinical conditions; however it is not until recently, that biological mechanisms have been uncovered that link both MDD and CHD. The activation of stress pathways have been implicated as a neurochemical mechanism that links MDD and CHD. Depression is known to be associated with poorer outcomes of CHD. Psychological factors such as major depression and stress are now known as risk factors for developing CHD which is as important and is independent of classic risk factors such as hypertension, diabetes mellitus and cigarette smoking. Both conditions have great socioeconomic importance given that depression and CHD are likely to be two of the three leading causes of global burden of disease. Better understanding of the common causal pathways will help us delineate more appropriate treatments.

  8. Performance measurements of a data link protocol

    Science.gov (United States)

    Kanakia, Hemant; Tobagi, Fouad

    The end-to-end performance of a program implementing IEEE Std 802.2 logical link control protocol, which provides virtual circuit and datagram service and which constitutes the top sublayer of the data link layer of the reference model for Local Area Networks is studied. The measurements of relative execution times of various functions required in transferring data, over virtual circuits or as datagrams, showed that most of the program execution time is spent in a few relatively low-level functions. One of these functions performs block movement of data in memory, and two other functions provide access to various queues. Based on this result, two alternative versions of the program which move data efficiently were written and measured. In this paper the results of the study are reported and their impact on designing hardware and software systems for a network interface are discussed.

  9. IVOA recommendation: IVOA DataLink

    CERN Document Server

    Dowler, Patrick; Michel, Laurent; Demleitner, Markus

    2015-01-01

    This document describes the linking of data discovery metadata to access to the data itself, further detailed metadata, related resources, and to services that perform operations on the data. The web service capability supports a drill-down into the details of a specific dataset and provides a set of links to the dataset file(s) and related resources. This specification also includes a VOTable-specific method of providing descriptions of one or more services and their input(s), usually using parameter values from elsewhere in the VOTable document. Providers are able to describe services that are relevant to the records (usually datasets with identifiers) by including service descriptors in a result document.

  10. kpath: integration of metabolic pathway linked data.

    Science.gov (United States)

    Navas-Delgado, Ismael; García-Godoy, María Jesús; López-Camacho, Esteban; Rybinski, Maciej; Reyes-Palomares, Armando; Medina, Miguel Ángel; Aldana-Montes, José F

    2015-01-01

    In the last few years, the Life Sciences domain has experienced a rapid growth in the amount of available biological databases. The heterogeneity of these databases makes data integration a challenging issue. Some integration challenges are locating resources, relationships, data formats, synonyms or ambiguity. The Linked Data approach partially solves the heterogeneity problems by introducing a uniform data representation model. Linked Data refers to a set of best practices for publishing and connecting structured data on the Web. This article introduces kpath, a database that integrates information related to metabolic pathways. kpath also provides a navigational interface that enables not only the browsing, but also the deep use of the integrated data to build metabolic networks based on existing disperse knowledge. This user interface has been used to showcase relationships that can be inferred from the information available in several public databases.

  11. [Corneal collagen cross-linking for keratoconus].

    Science.gov (United States)

    Zotov, V V; Pashtaev, N P; Pozdeeva, N A

    2015-01-01

    Over the last decade, corneal collagen cross-linking (CXL) has become a conventional treatment method for progressive keratoconus. Laboratory studies have shown that CXL increases the diameter of collagen fibers and also the number of intra- and interfibrillar cross-links, thus, increasing biomechanical strength of the irradiated cornea. As confirmed by a series of clinical and randomized controlled trials, CXL is able to slow down and, perhaps, to stop the progression of keratoconus. In most post-CXL patients visual acuity improves, while keratometric readings, spherical equivalent, and higher order aberrations reduce. Although published results prove CXL effective in the treatment of progressive keratoconus, its late consequences are yet unknown. This article reviews the stages of CXL development and results of published experimental and clinical studies. Prospects for CXL modifications that do not require epithelial debridement are discussed.

  12. Link failure detection in a parallel computer

    Science.gov (United States)

    Archer, Charles J.; Blocksome, Michael A.; Megerian, Mark G.; Smith, Brian E.

    2010-11-09

    Methods, apparatus, and products are disclosed for link failure detection in a parallel computer including compute nodes connected in a rectangular mesh network, each pair of adjacent compute nodes in the rectangular mesh network connected together using a pair of links, that includes: assigning each compute node to either a first group or a second group such that adjacent compute nodes in the rectangular mesh network are assigned to different groups; sending, by each of the compute nodes assigned to the first group, a first test message to each adjacent compute node assigned to the second group; determining, by each of the compute nodes assigned to the second group, whether the first test message was received from each adjacent compute node assigned to the first group; and notifying a user, by each of the compute nodes assigned to the second group, whether the first test message was received.

  13. Link Graph Analysis for Adult Images Classification

    CERN Document Server

    Kharitonov, Evgeny; Muchnik, Ilya; Romanenko, Fedor; Belyaev, Dmitry; Kotlyarov, Dmitry

    2010-01-01

    In order to protect an image search engine's users from undesirable results adult images' classifier should be built. The information about links from websites to images is employed to create such a classifier. These links are represented as a bipartite website-image graph. Each vertex is equipped with scores of adultness and decentness. The scores for image vertexes are initialized with zero, those for website vertexes are initialized according to a text-based website classifier. An iterative algorithm that propagates scores within a website-image graph is described. The scores obtained are used to classify images by choosing an appropriate threshold. The experiments on Internet-scale data have shown that the algorithm under consideration increases classification recall by 17% in comparison with a simple algorithm which classifies an image as adult if it is connected with at least one adult site (at the same precision level).

  14. Regulatory mechanisms link phenotypic plasticity to evolvability.

    Science.gov (United States)

    van Gestel, Jordi; Weissing, Franz J

    2016-04-18

    Organisms have a remarkable capacity to respond to environmental change. They can either respond directly, by means of phenotypic plasticity, or they can slowly adapt through evolution. Yet, how phenotypic plasticity links to evolutionary adaptability is largely unknown. Current studies of plasticity tend to adopt a phenomenological reaction norm (RN) approach, which neglects the mechanisms underlying plasticity. Focusing on a concrete question - the optimal timing of bacterial sporulation - we here also consider a mechanistic approach, the evolution of a gene regulatory network (GRN) underlying plasticity. Using individual-based simulations, we compare the RN and GRN approach and find a number of striking differences. Most importantly, the GRN model results in a much higher diversity of responsive strategies than the RN model. We show that each of the evolved strategies is pre-adapted to a unique set of unseen environmental conditions. The regulatory mechanisms that control plasticity therefore critically link phenotypic plasticity to the adaptive potential of biological populations.

  15. Classification of Framed Links in 3-Manifolds

    Indian Academy of Sciences (India)

    Matija Cencelj; Dušan Repovš; Mikhail B Skopenkov

    2007-08-01

    We present a short and complete proof of the following Pontryagin theorem, whose original proof was complicated and has never been published in detail. Let be a connected oriented closed smooth 3-manifold, $L_1(M)$ be the set of framed links in up to a framed cobordism, and $\\deg: L_1(M)→ H_1(M;\\mathbb{Z})$ be the map taking a framed link to its homology class. Then for each $\\in H_1(M;\\mathbb{Z})$ there is a one-to-one correspondence between the set $\\deg^{-1}$ and the group $\\mathbb{Z}_{2d()}$, where () is the divisibility of the projection of to the free part of $H_1(M;\\mathbb{Z})$.

  16. Phase slips in superconducting weak links

    Energy Technology Data Exchange (ETDEWEB)

    Kimmel, Gregory; Glatz, Andreas; Aranson, Igor S.

    2017-01-01

    Superconducting vortices and phase slips are primary mechanisms of dissipation in superconducting, superfluid, and cold-atom systems. While the dynamics of vortices is fairly well described, phase slips occurring in quasi-one- dimensional superconducting wires still elude understanding. The main reason is that phase slips are strongly nonlinear time-dependent phenomena that cannot be cast in terms of small perturbations of the superconducting state. Here we study phase slips occurring in superconducting weak links. Thanks to partial suppression of superconductivity in weak links, we employ a weakly nonlinear approximation for dynamic phase slips. This approximation is not valid for homogeneous superconducting wires and slabs. Using the numerical solution of the time-dependent Ginzburg-Landau equation and bifurcation analysis of stationary solutions, we show that the onset of phase slips occurs via an infinite period bifurcation, which is manifested in a specific voltage-current dependence. Our analytical results are in good agreement with simulations.

  17. An Accurate Link Correlation Estimator for Improving Wireless Protocol Performance

    Directory of Open Access Journals (Sweden)

    Zhiwei Zhao

    2015-02-01

    Full Text Available Wireless link correlation has shown significant impact on the performance of various sensor network protocols. Many works have been devoted to exploiting link correlation for protocol improvements. However, the effectiveness of these designs heavily relies on the accuracy of link correlation measurement. In this paper, we investigate state-of-the-art link correlation measurement and analyze the limitations of existing works. We then propose a novel lightweight and accurate link correlation estimation (LACE approach based on the reasoning of link correlation formation. LACE combines both long-term and short-term link behaviors for link correlation estimation. We implement LACE as a stand-alone interface in TinyOS and incorporate it into both routing and flooding protocols. Simulation and testbed results show that LACE: (1 achieves more accurate and lightweight link correlation measurements than the state-of-the-art work; and (2 greatly improves the performance of protocols exploiting link correlation.

  18. An Accurate Link Correlation Estimator for Improving Wireless Protocol Performance

    Science.gov (United States)

    Zhao, Zhiwei; Xu, Xianghua; Dong, Wei; Bu, Jiajun

    2015-01-01

    Wireless link correlation has shown significant impact on the performance of various sensor network protocols. Many works have been devoted to exploiting link correlation for protocol improvements. However, the effectiveness of these designs heavily relies on the accuracy of link correlation measurement. In this paper, we investigate state-of-the-art link correlation measurement and analyze the limitations of existing works. We then propose a novel lightweight and accurate link correlation estimation (LACE) approach based on the reasoning of link correlation formation. LACE combines both long-term and short-term link behaviors for link correlation estimation. We implement LACE as a stand-alone interface in TinyOS and incorporate it into both routing and flooding protocols. Simulation and testbed results show that LACE: (1) achieves more accurate and lightweight link correlation measurements than the state-of-the-art work; and (2) greatly improves the performance of protocols exploiting link correlation. PMID:25686314

  19. Link between chips and cutting moments evolution

    CERN Document Server

    Cahuc, Olivier; Gérard, Alain; 10.4028/WWW.scientific.net/AMR.423.89

    2012-01-01

    The better understanding of the material cutting process has been shown with the benefit of the forces and moments measurement since some years ago. In paper, simultaneous six mechanical components and chip orientation measurements were realized during turning tests. During these tests, the influence of the depth of cut or feed rate has been observed and a link between the chip orientation and the moment vector orientation or the central axis characteristics has been shown.

  20. Link Biased Strategies in Network Formation Games

    OpenAIRE

    Lichter, Shaun; Griffin, Christopher; Friesz, Terry

    2011-01-01

    We show a simple method for constructing an infinite family of graph formation games with link bias so that the resulting games admits, as a \\textit{pairwise stable} solution, a graph with an arbitrarily specified degree distribution. Pairwise stability is used as the equilibrium condition over the more commonly used Nash equilibrium to prevent the occurrence of ill-behaved equilibrium strategies that do not occur in ordinary play. We construct this family of games by solving an integer progr...

  1. Characterization of Cross-Linked Lipase Aggregates

    DEFF Research Database (Denmark)

    Prabhavathi Devi, Bethala Lakshmi Anu; Guo, Zheng; Xu, Xuebing

    2009-01-01

    Commercially available microbial lipases from different sources were immobilized as cross-linked enzyme aggregates (CLEAs) using different precipitants and glutaraldehyde as cross-linkers. These CLEAs were assayed based on esterification between lauric acid and n-propanol in solvent-free systems...... change upon CLEA formation. This work presents a characterization of CLEAs based on an esterification activity assay, which is useful for exploring the synthetic application potential of CLEA technology with favorable perspectives....

  2. DeckLink SDI采集卡

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Blackmagic Design的DeckLink SDI采集卡,具有高质量10b高/标清SDI采集和回放能力。它还配有广播级SDI,能够在SD—SDI和HD—SDI格式之间即时转换,非常适合连接HDCAM、HD—D5和Digital Betacam等录机。

  3. Sexuality and occupational therapy: Exploring the link

    OpenAIRE

    Simó i Algado, Salvador; Sakellariou, Dikaios

    2006-01-01

    Holism is perceived to be one of the major tenets of occupational therapy. This article discusses the relevance of sexuality to holistic health care and contributes to the continuing discussion regarding the legitimacy of sexuality as an area of concern for occupational therapists. Sexuality is an important part of the human experience and is linked closely with spirituality. However, it is often neglected by occupational therapists. The article explores the occupational nat...

  4. Linking Virus Genomes with Host Taxonomy.

    Science.gov (United States)

    Mihara, Tomoko; Nishimura, Yosuke; Shimizu, Yugo; Nishiyama, Hiroki; Yoshikawa, Genki; Uehara, Hideya; Hingamp, Pascal; Goto, Susumu; Ogata, Hiroyuki

    2016-03-01

    Environmental genomics can describe all forms of organisms--cellular and viral--present in a community. The analysis of such eco-systems biology data relies heavily on reference databases, e.g., taxonomy or gene function databases. Reference databases of symbiosis sensu lato, although essential for the analysis of organism interaction networks, are lacking. By mining existing databases and literature, we here provide a comprehensive and manually curated database of taxonomic links between viruses and their cellular hosts.

  5. Nanophotonics: The link between nanotechnology and photonics

    CSIR Research Space (South Africa)

    Sinha Ray, S

    2012-10-01

    Full Text Available and importance ? CSIR 2012 www.csir.co.za/nano Slide 2 ? Birth and definition of nanotechnology ? Benefits of nanotechnology ? The link between nanotechnology and photonics: Nanophotonics ? Importance and future of nanophotonics... of maneuvering things atom by atom. It is not an attempt to violate any laws; it is something, in principle, that can be done; but in practice, it has not been done because we are too big ? Richard Feynman, 1959 Birth of Nanoscience and Nanotechnology 1980...

  6. Personalized Federated Search at LinkedIn

    OpenAIRE

    Arya, Dhruv; Ha-Thuc, Viet; Sinha, Shakti

    2016-01-01

    LinkedIn has grown to become a platform hosting diverse sources of information ranging from member profiles, jobs, professional groups, slideshows etc. Given the existence of multiple sources, when a member issues a query like "software engineer", the member could look for software engineer profiles, jobs or professional groups. To tackle this problem, we exploit a data-driven approach that extracts searcher intents from their profile data and recent activities at a large scale. The intents s...

  7. Non-specific X linked mental retardation.

    OpenAIRE

    Kerr, B.; Turner, G; Mulley, J.; Gedeon, A; PARTINGTON, M.

    1991-01-01

    Non-specific X linked mental retardation (MRX) is mental retardation in persons of normal physical appearance who have no recognisable features apart from a characteristic pedigree. Review of published reports shows that there is clinical variability in the degree of mental retardation within families and genetic heterogeneity, based on gene localisation, between families. We propose a classification based on genetic localisation and a set of minimal clinical features that should be recorded ...

  8. Hypercubic smeared links for dynamical fermions

    Energy Technology Data Exchange (ETDEWEB)

    Hasenfratz, A.; Hoffmann, R. [Colorado Univ., Boulder, CO (United States). Dept. of Physics; Schaefer, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC

    2007-02-15

    We investigate a variant of hypercubic gauge link smearing where the SU(3) projection is replaced with a normalization to the corresponding unitary group. This smearing is differentiable and thus suitable for use in dynamical fermion simulations using molecular dynamics type algorithms. We show that this smearing is as efficient as projected hypercubic smearing in removing ultraviolet noise from the gauge fields. We test the normalized hypercubic smearing in dynamical improved (clover) Wilson and valence overlap simulations. (orig.)

  9. Linking obesogenic dysregulation to prostate cancer progression

    OpenAIRE

    Taylor, Renea A.; Lo, Jennifer; Ascui, Natasha; Watt, Matthew J.

    2015-01-01

    The global epidemic of obesity is closely linked to the development of serious co-morbidities, including many forms of cancer. Epidemiological evidence consistently shows that obesity is associated with a similar or mildly increased incidence of prostate cancer but, more prominently, an increased risk for aggressive prostate cancer and prostate cancer-specific mortality. Studies in mice demonstrate that obesity induced by high-fat feeding increases prostate cancer progression; however, the me...

  10. Thermal Analyse sof Cross-Linked Polyethylene

    Directory of Open Access Journals (Sweden)

    Radek Polansky

    2007-01-01

    Full Text Available The paper summarizes results obtained during the structural analyses measurements (Differential Scanning Calorimetry DSC, Thermogravimetry TG, Thermomechanical analysis TMA and Fourier transform infrared spectroscopy FT-IR. The samples of cross-linked polyethylene cable insulation were tested via these analyses. The DSC and TG were carried out using simultaneous thermal analyzer TA Instruments SDT Q600 with connection of Fourier transform infrared spectrometer Nicolet 380. Thermomechanical analysis was carried out by TMA Q400EM TA Instruments apparatus.

  11. The BREMSAT Phase-Modulated Communications Link

    OpenAIRE

    Lefevre, Don

    1990-01-01

    BREMSAT is a small scientific satellite being constructed by the west German Zentrum fur angewandte Raumfahrttechnologie und Mikrogravitation (ZARM), at Bremen University. BREMSAT's payload consists of five scientific experiment packages. The satellite is scheduled for Get-Away-Special (GAS) Canister launch during the German D-2 shuttle mission in March 1992. Cynetics Corporation is constructing the TT&C link for the satellite, using its standard CMX9600 modem. This modem is the result of Cyn...

  12. A New Approach to the Link Budget Concept for an OAM Communication Link

    CERN Document Server

    Cagliero, Andrea; Gaffoglio, Rossella; Sacco, Bruno

    2015-01-01

    Following on from the increasing interest for electromagnetic waves carrying Orbital Angular Momentum (OAM), different configurations of antenna systems able to generate such beams have been proposed. However, in our opinion, a traditional radiation pattern approach does not provide the right picture of an OAM-based communication link. For this reason we propose a new general concept, the "OAM-link pattern", which takes into account the peculiar phase structure characterizing these waves. Focusing on OAM transmissions between antenna arrays, we introduce a formula for the link budget evaluation which describes the whole communication link and directly leads to a "classically shaped" main lobe pattern for a proper rephased reception in the case of uniform circular arrays.

  13. Blind links, a big challenge in the linked data idea: Analysis of Persian Subject Headings

    Directory of Open Access Journals (Sweden)

    Atefeh Sharif

    2014-12-01

    Full Text Available In this survey, Linked data concept as exposing, sharing, and connecting pieces of data, information, and knowledge on the Semantic Web and some potential problems in converting Persian subject headings (PSHs Records into linked data were discussed. A data set (11233 records of PSHs was searched in three information retrieval systems including National Library of Iran (NLI online catalog, Library of Congress (LC online catalog and NOSA books. Correct links between Persian and English subject headings in the 9519 common records of two catalogs were recorded. The results indicate that the links between Persian and English subjects in 20% of records were failed. The maximum error was associated with the anonymous databases (6/7 % in NLI online catalog. It is recommended to preprocess the PSHs records before any conversion projects. It seems that, during the preprocessing, the potential errors could be identified and corrected.

  14. Linked Health Data: how linked data can help provide better health decisions.

    Science.gov (United States)

    Farinelli, Fernanda; Barcellos de Almeida, Maurício; Linhares de Souza, Yóris

    2015-01-01

    This paper provides a brief survey about the use of linked data in healthcare to foster better health decisions and increase health knowledge. We present real cases from the Brazilian experience and emphasize some issues in research. This paper is not intending to be fully comprehensive, we discuss some open issues and research challenges in linked data and the technologies involved. We conclude that even though linked data has been adopted in many countries, some challenges have to be overcome, for example, interoperability between different standards. A defined solution able to foster the semantic interoperability between different standards must be developed. Benefits contributed through linked health data involve better decision making on diagnostics, assertive treatments, knowledge acquisition, improvements in quality healthcare service to citizens.

  15. Chloroacetamide-Linked Nucleotides and DNA for Cross-Linking with Peptides and Proteins.

    Science.gov (United States)

    Olszewska, Agata; Pohl, Radek; Brázdová, Marie; Fojta, Miroslav; Hocek, Michal

    2016-09-21

    Nucleotides, 2'-deoxyribonucleoside triphosphates (dNTPs), and DNA probes bearing reactive chloroacetamido group linked to nucleobase (cytosine or 7-deazadaenine) through a propargyl tether were prepared and tested in cross-linking with cysteine- or histidine-containing peptides and proteins. The chloroacetamide-modifed dNTPs proved to be good substrates for DNA polymerases in the enzymatic synthesis of modified DNA probes. Modified nucleotides and DNA reacted efficiently with cysteine and cysteine-containing peptides, whereas the reaction with histidine was sluggish and low yielding. The modified DNA efficiently cross-linked with p53 protein through alkylation of cysteine and showed potential for cross-linking with histidine (in C277H mutant of p53).

  16. The linked medical data access control framework.

    Science.gov (United States)

    Kamateri, Eleni; Kalampokis, Evangelos; Tambouris, Efthimios; Tarabanis, Konstantinos

    2014-08-01

    The integration of medical data coming from multiple sources is important in clinical research. Amongst others, it enables the discovery of appropriate subjects in patient-oriented research and the identification of innovative results in epidemiological studies. At the same time, the integration of medical data faces significant ethical and legal challenges that impose access constraints. Some of these issues can be addressed by making available aggregated instead of raw record-level data. In many cases however, there is still a need for controlling access even to the resulting aggregated data, e.g., due to data provider's policies. In this paper we present the Linked Medical Data Access Control (LiMDAC) framework that capitalizes on Linked Data technologies to enable controlling access to medical data across distributed sources with diverse access constraints. The LiMDAC framework consists of three Linked Data models, namely the LiMDAC metadata model, the LiMDAC user profile model, and the LiMDAC access policy model. It also includes an architecture that exploits these models. Based on the framework, a proof-of-concept platform is developed and its performance and functionality are evaluated by employing two usage scenarios.

  17. Arthritis and X-linked agammaglobulinemia.

    Science.gov (United States)

    Machado, Pedro; Santos, Alexandra; Faria, Emília; Silva, Jorge; Malcata, Armando; Chieira, Celso

    2008-01-01

    Primary immunodeficiencies are defined as genetically determined functional and/or quantitative abnormalities in one or more of the components of the immune system. Immunodeficiency and arthritis can be related, although the mechanisms are not always clear. Different causes for immunodeficiency can secondarily be found in patients with arthritis; on the other hand, arthritis can be a manifestation of primary immunodeficiency. Arthritis occurs chiefly in humoral primary immunodeficiencies, namely in X-linked agammaglobulinemia and common variable immunodeficiency, and may be one of the warning signs for primary immunodeficiency. We report a case of arthritis as the presenting feature of X-linked agammaglobulinemia. In X-linked agammaglobulinemia, arthritis may be a consequence of infection, most notably by Mycoplasma, or of immune dysfunction itself. In children, and occasionally in young adults, a combination of arthritis and hypogammaglobulinemia should suggest primary immunodeficiency, although other causes of hypogammaglobulinemia must be excluded. Physicians evaluating patients with arthritis should be aware of this fact so that an early diagnosis can be pursued as it is of extreme importance in the optimal management and prognosis of these patients.

  18. Collagen cross-linking in thin corneas

    Directory of Open Access Journals (Sweden)

    Prema Padmanabhan

    2013-01-01

    Full Text Available Collagen cross-linking (CXL has become the standard of care for progressive keratoconus, after numerous clinical studies have established its efficacy and safety in suitably selected eyes. The standard protocol is applicable in eyes which have a minimum corneal thickness of 400 μm after epithelial debridement. This prerequisite was stipulated to protect the corneal endothelium and intraocular tissues from the deleterious effect of ultraviolet-A (UVA radiation. However, patients with keratoconus often present with corneal thickness of less than 400 μm and could have otherwise benefited from this procedure. A few modifications of the standard procedure have been suggested to benefit these patients without a compromise in safety. Transepithelial cross-linking, pachymetry-guided epithelial debridement before cross-linking, and the use of hypoosmolar riboflavin are some of the techniques that have been attempted. Although clinical data is limited at the present time, these techniques are worth considering in patients with thin corneas. Further studies are needed to scientifically establish their efficacy and safety.

  19. DOIs Should Not Link to Data

    Science.gov (United States)

    Hourcle, J. A.

    2013-12-01

    In August of 2011, the National Academy of Science's Board of Research Data and Information (BRDI) had a meeting on the topic of "Developing Data Attribution and Citation Practices and Standards". As part of that meeting were various breakout groups to discuss issues that still remained regarding technical, scientific, and socio-cultural issues, the roles and actors that needed to be involved, and how to get additional feedback from the community. The technical breakout group decided that the majority of the technical problems with citing data revolved around establishing the identity of what it was that we were attempting to cite. As such, our recommendations were to push some of the work back onto the data publishers to tell us how scientists should cite their data (to avoid different disciplines applying different rules), establish 'data landing pages' to describe, document and link to the data, and to provide those pages with persistent identifiers such as a DOI. We present here some of the reasons that were discussed about why not to link directly to data, including: * recalibration, reaccessioning and other data impermanence, * setting context and providing for links to documentation, and * allowing selection of different packaging formats

  20. Local Community Detection Using Link Similarity

    Institute of Scientific and Technical Information of China (English)

    Ying-Jun Wu; Han Huang; Zhi-Feng Hao; Feng Chen

    2012-01-01

    Exploring local community structure is an appealing problem that has drawn much recent attention in the area of social network analysis.As the complete information of network is often difficult to obtain,such as networks of web pages,research papers and Facebook users,people can only detect community structure from a certain source vertex with limited knowledge of the entire graph.The existing approaches do well in measuring the community quality,but they are largely dependent on source vertex and putting too strict policy in agglomerating new vertices.Moreover,they have predefined parameters which are difficult to obtain.This paper proposes a method to find local community structure by analyzing link similarity between the community and the vertex.Inspired by the fact that elements in the same community are more likely to share common links,we explore community structure heuristically by giving priority to vertices which have a high link similarity with the community.A three-phase process is also used for the sake of improving quality of community structure.Experimental results prove that our method performs effectively not only in computer-generated graphs but also in real-world graphs.

  1. Radio link quality estimation in low-power wireless networks

    CERN Document Server

    2013-01-01

    This book provides a comprehensive survey on related work for radio link quality estimation, which covers the characteristics of low-power links, the fundamental concepts of link quality estimation in wireless sensor networks, a taxonomy of existing link quality estimators and their performance analysis. It then shows how link quality estimation can be used for designing protocols and mechanisms such as routing and hand-off. The final part is dedicated to radio interference estimation, generation and mitigation.

  2. Active semi-supervised community detection based on must-link and cannot-link constraints.

    Directory of Open Access Journals (Sweden)

    Jianjun Cheng

    Full Text Available Community structure detection is of great importance because it can help in discovering the relationship between the function and the topology structure of a network. Many community detection algorithms have been proposed, but how to incorporate the prior knowledge in the detection process remains a challenging problem. In this paper, we propose a semi-supervised community detection algorithm, which makes full utilization of the must-link and cannot-link constraints to guide the process of community detection and thereby extracts high-quality community structures from networks. To acquire the high-quality must-link and cannot-link constraints, we also propose a semi-supervised component generation algorithm based on active learning, which actively selects nodes with maximum utility for the proposed semi-supervised community detection algorithm step by step, and then generates the must-link and cannot-link constraints by accessing a noiseless oracle. Extensive experiments were carried out, and the experimental results show that the introduction of active learning into the problem of community detection makes a success. Our proposed method can extract high-quality community structures from networks, and significantly outperforms other comparison methods.

  3. Challenges and Usage of Link Mining to Semantic Web

    Directory of Open Access Journals (Sweden)

    Zaved Akhtar

    2012-03-01

    Full Text Available - It is an emerging challenge for data mining is the problem of mining richly structures datasets, where the objects are linked in some way. Links among the objects may demonstrate certain patterns, which can be helpful for many data mining tasks and are usually hard to capture with traditional statistical models. Many datasets of interest today are best described as a linked collection of interrelated objects. These may represent homogeneous networks, in which there is a single-object type and link type (eg. people connected by friendship links, or the WWW, a collection of linked web pages or richer, heterogeneous networks, in which there may be multiple object and link types (and possibly other semantic information. Examples of heterogeneous networks include those in medical domains describing patients, diseases, treatments and contacts, or in bibliographic domains describing publications, authors, and venues. Link mining refers to data mining techniques that explicitly consider these links when building predictive or descriptive models of the linked data. Commonly addressed link mining tasks include object ranking, group detection, collective classification, link prediction and subgraph discovery. This is an exciting and rapidly expanding area. In this article we review some of the common emerging themes and discuss ongoing link mining challenges; open issues and suggest ideas that could be opportunities for solutions. The most conclusion of this article is that providing an idea to usage link mining techniques from link mining to help to construct the Semantic Web.

  4. Simulation of Link-16 Data Link Signal%Link-16数据链信号模拟

    Institute of Scientific and Technical Information of China (English)

    张允

    2013-01-01

    分析了Link-16数据链信号的特点,描述了数据链的时隙结构、信号时序以及跳频、跳时、信息编码、扩频等实现过程,结合工程实际阐述了信号的产生方法,模拟产生了数据链终端发送的射频信号.

  5. Hybrid UWB and WiMAX radio-over-multi-mode fibre for in-building optical networks

    Science.gov (United States)

    Perez, J.; Llorente, R.

    2014-01-01

    In this paper the use of hybrid WiMedia-defined ultra-wideband (UWB) and IEEE 802.16d WiMAX radio-over-fibre is proposed and experimentally demonstrated for multi-mode based in-building optical networks with the advantage of great immunity to optical transmission impairments. In the proposed approach, spectral coexistence of both signals must be achieved with negligible mutual interference. The experimental study performed addressed an indoor configuration with 50 μm multi-mode fibres (MMF) and 850 nm vertical-cavity surface-emitting laser (VCSEL) transmitters. The results indicate that the impact of the wireless convergence in radio-over-multi-mode fibre (RoMMF) is significant for UWB transmissions, mainly due to MMF dispersion and electrooptical (EO) devices with limited bandwidth. On the other hand, WiMAX transmission is feasible for a 300 m MMF and 30 m wireless link in the presence of UWB, with -31 dBm WiMAX EVM.

  6. Laser links for mobile airborne nodes

    Science.gov (United States)

    Griethe, Wolfgang; Knapek, Markus; Horwath, Joachim

    2015-05-01

    Remotely Piloted Aircrafts (RPA's) and especially Medium Altitude Long Endurance (MALE) and High Altitude Long Endurance (HALE) are currently operated over long distances, often across several continents. This is only made possible by maintaining Beyond Line Of Side (BLOS) radio links between ground control stations and unmanned vehicles via geostationary (GEO) satellites. The radio links are usually operated in the Ku-frequency band and used for both, vehicle command & control (C2) - it also refers to Command and Non-Payload Communication (CNPC) - as well as transmission of intelligence data - the associated communication stream also refers to Payload Link (PL). Even though this scheme of communication is common practice today, various other issues are raised thereby. The paper shows that the current existing problems can be solved by using the latest technologies combined with altered intuitive communication strategies. In this context laser communication is discussed as a promising technology for airborne applications. It is clearly seen that for tactical reasons, as for instance RPA cooperative flying, Air-to-Air communications (A2A) is more advantageous than GEO satellite communications (SatCom). Hence, together with in-flight test results the paper presents a design for a lightweight airborne laser terminal, suitable for use onboard manned or unmanned airborne nodes. The advantages of LaserCom in combination with Intelligence, Surveillance and Reconnaissance (ISR) technologies particularly for Persistent Wide Area Surveillance (PWAS) are highlighted. Technical challenges for flying LaserCom terminals aboard RPA's are outlined. The paper leads to the conclusion that by combining both, LaserCom and ISR, a new quality for an overall system arises which is more than just the sum of two separate key technologies.

  7. Optical links in handheld multimedia devices

    Science.gov (United States)

    van Geffen, S.; Duis, J.; Miller, R.

    2008-04-01

    Ever emerging applications in handheld multimedia devices such as mobile phones, laptop computers, portable video games and digital cameras requiring increased screen resolutions are driving higher aggregate bitrates between host processor and display(s) enabling services such as mobile video conferencing, video on demand and TV broadcasting. Larger displays and smaller phones require complex mechanical 3D hinge configurations striving to combine maximum functionality with compact building volumes. Conventional galvanic interconnections such as Micro-Coax and FPC carrying parallel digital data between host processor and display module may produce Electromagnetic Interference (EMI) and bandwidth limitations caused by small cable size and tight cable bends. To reduce the number of signals through a hinge, the mobile phone industry, organized in the MIPI (Mobile Industry Processor Interface) alliance, is currently defining an electrical interface transmitting serialized digital data at speeds >1Gbps. This interface allows for electrical or optical interconnects. Above 1Gbps optical links may offer a cost effective alternative because of their flexibility, increased bandwidth and immunity to EMI. This paper describes the development of optical links for handheld communication devices. A cable assembly based on a special Plastic Optical Fiber (POF) selected for its mechanical durability is terminated with a small form factor molded lens assembly which interfaces between an 850nm VCSEL transmitter and a receiving device on the printed circuit board of the display module. A statistical approach based on a Lean Design For Six Sigma (LDFSS) roadmap for new product development tries to find an optimum link definition which will be robust and low cost meeting the power consumption requirements appropriate for battery operated systems.

  8. Musical Preferences are Linked to Cognitive Styles.

    Science.gov (United States)

    Greenberg, David M; Baron-Cohen, Simon; Stillwell, David J; Kosinski, Michal; Rentfrow, Peter J

    2015-01-01

    Why do we like the music we do? Research has shown that musical preferences and personality are linked, yet little is known about other influences on preferences such as cognitive styles. To address this gap, we investigated how individual differences in musical preferences are explained by the empathizing-systemizing (E-S) theory. Study 1 examined the links between empathy and musical preferences across four samples. By reporting their preferential reactions to musical stimuli, samples 1 and 2 (Ns = 2,178 and 891) indicated their preferences for music from 26 different genres, and samples 3 and 4 (Ns = 747 and 320) indicated their preferences for music from only a single genre (rock or jazz). Results across samples showed that empathy levels are linked to preferences even within genres and account for significant proportions of variance in preferences over and above personality traits for various music-preference dimensions. Study 2 (N = 353) replicated and extended these findings by investigating how musical preferences are differentiated by E-S cognitive styles (i.e., 'brain types'). Those who are type E (bias towards empathizing) preferred music on the Mellow dimension (R&B/soul, adult contemporary, soft rock genres) compared to type S (bias towards systemizing) who preferred music on the Intense dimension (punk, heavy metal, and hard rock). Analyses of fine-grained psychological and sonic attributes in the music revealed that type E individuals preferred music that featured low arousal (gentle, warm, and sensual attributes), negative valence (depressing and sad), and emotional depth (poetic, relaxing, and thoughtful), while type S preferred music that featured high arousal (strong, tense, and thrilling), and aspects of positive valence (animated) and cerebral depth (complexity). The application of these findings for clinicians, interventions, and those on the autism spectrum (largely type S or extreme type S) are discussed.

  9. Musical Preferences are Linked to Cognitive Styles

    Science.gov (United States)

    Greenberg, David M.; Baron-Cohen, Simon; Stillwell, David J.; Kosinski, Michal; Rentfrow, Peter J.

    2015-01-01

    Why do we like the music we do? Research has shown that musical preferences and personality are linked, yet little is known about other influences on preferences such as cognitive styles. To address this gap, we investigated how individual differences in musical preferences are explained by the empathizing-systemizing (E-S) theory. Study 1 examined the links between empathy and musical preferences across four samples. By reporting their preferential reactions to musical stimuli, samples 1 and 2 (Ns = 2,178 and 891) indicated their preferences for music from 26 different genres, and samples 3 and 4 (Ns = 747 and 320) indicated their preferences for music from only a single genre (rock or jazz). Results across samples showed that empathy levels are linked to preferences even within genres and account for significant proportions of variance in preferences over and above personality traits for various music-preference dimensions. Study 2 (N = 353) replicated and extended these findings by investigating how musical preferences are differentiated by E-S cognitive styles (i.e., ‘brain types’). Those who are type E (bias towards empathizing) preferred music on the Mellow dimension (R&B/soul, adult contemporary, soft rock genres) compared to type S (bias towards systemizing) who preferred music on the Intense dimension (punk, heavy metal, and hard rock). Analyses of fine-grained psychological and sonic attributes in the music revealed that type E individuals preferred music that featured low arousal (gentle, warm, and sensual attributes), negative valence (depressing and sad), and emotional depth (poetic, relaxing, and thoughtful), while type S preferred music that featured high arousal (strong, tense, and thrilling), and aspects of positive valence (animated) and cerebral depth (complexity). The application of these findings for clinicians, interventions, and those on the autism spectrum (largely type S or extreme type S) are discussed. PMID:26200656

  10. Musical Preferences are Linked to Cognitive Styles.

    Directory of Open Access Journals (Sweden)

    David M Greenberg

    Full Text Available Why do we like the music we do? Research has shown that musical preferences and personality are linked, yet little is known about other influences on preferences such as cognitive styles. To address this gap, we investigated how individual differences in musical preferences are explained by the empathizing-systemizing (E-S theory. Study 1 examined the links between empathy and musical preferences across four samples. By reporting their preferential reactions to musical stimuli, samples 1 and 2 (Ns = 2,178 and 891 indicated their preferences for music from 26 different genres, and samples 3 and 4 (Ns = 747 and 320 indicated their preferences for music from only a single genre (rock or jazz. Results across samples showed that empathy levels are linked to preferences even within genres and account for significant proportions of variance in preferences over and above personality traits for various music-preference dimensions. Study 2 (N = 353 replicated and extended these findings by investigating how musical preferences are differentiated by E-S cognitive styles (i.e., 'brain types'. Those who are type E (bias towards empathizing preferred music on the Mellow dimension (R&B/soul, adult contemporary, soft rock genres compared to type S (bias towards systemizing who preferred music on the Intense dimension (punk, heavy metal, and hard rock. Analyses of fine-grained psychological and sonic attributes in the music revealed that type E individuals preferred music that featured low arousal (gentle, warm, and sensual attributes, negative valence (depressing and sad, and emotional depth (poetic, relaxing, and thoughtful, while type S preferred music that featured high arousal (strong, tense, and thrilling, and aspects of positive valence (animated and cerebral depth (complexity. The application of these findings for clinicians, interventions, and those on the autism spectrum (largely type S or extreme type S are discussed.

  11. Linking microarray reporters with protein functions

    Directory of Open Access Journals (Sweden)

    Gaj Stan

    2007-09-01

    Full Text Available Abstract Background The analysis of microarray experiments requires accurate and up-to-date functional annotation of the microarray reporters to optimize the interpretation of the biological processes involved. Pathway visualization tools are used to connect gene expression data with existing biological pathways by using specific database identifiers that link reporters with elements in the pathways. Results This paper proposes a novel method that aims to improve microarray reporter annotation by BLASTing the original reporter sequences against a species-specific EMBL subset, that was derived from and crosslinked back to the highly curated UniProt database. The resulting alignments were filtered using high quality alignment criteria and further compared with the outcome of a more traditional approach, where reporter sequences were BLASTed against EnsEMBL followed by locating the corresponding protein (UniProt entry for the high quality hits. Combining the results of both methods resulted in successful annotation of > 58% of all reporter sequences with UniProt IDs on two commercial array platforms, increasing the amount of Incyte reporters that could be coupled to Gene Ontology terms from 32.7% to 58.3% and to a local GenMAPP pathway from 9.6% to 16.7%. For Agilent, 35.3% of the total reporters are now linked towards GO nodes and 7.1% on local pathways. Conclusion Our methods increased the annotation quality of microarray reporter sequences and allowed us to visualize more reporters using pathway visualization tools. Even in cases where the original reporter annotation showed the correct description the new identifiers often allowed improved pathway and Gene Ontology linking. These methods are freely available at http://www.bigcat.unimaas.nl/public/publications/Gaj_Annotation/.

  12. 45 Km Horizontal Path Optical Link Experiment

    Science.gov (United States)

    Biswas, A.; Ceniceros, J.; Novak, M.; Jeganathan, M.; Portillo, A.; Erickson, D.; Depew, J.; Sanii, B.; Lesh, J. R.

    2000-01-01

    Mountain-top to mountain-top optical link experiments have been initiated at JPL, in order to perform a systems level evaluation of optical communications. Progress made so far is reported. ne NASA, JPL developed optical communications demonstrator (OCD) is used to transmit a laser signal from Strawberry Peak (SP), located in the San Bernadino mountains of California. This laser beam is received by a 0.6 m aperture telescope at JPL's Table Mountain Facility (TMF), located in Wrightwood, California. The optical link is bi-directional with the TMF telescope transmitting a continuous 4-wave (cw) 780 run beacon and the OCD sending back a 840 nm, 100 - 500 Mbps pseudo noise (PN) modulated, laser beam. The optical link path is at an average altitude of 2 km above sea level, covers a range of 46.8 km and provides an atmospheric channel equivalent to approx. 4 air masses. Average received power measured at either end fall well within the uncertainties predicted by link analysis. The reduction in normalized intensity variance (sigma(sup 2, sub I)) for the 4-beam beacon, compared to each individual beam, at SP, was from approx. 0.68 to 0.22. With some allowance for intra-beam mis-alignment, this is consistent with incoherent averaging. The sigma(sup2, sub I) measured at TMF approx. 0.43 +/- 0.22 exceeded the expected aperture averaged value of less than 0.1, probably because of beam wander. The focused spot sizes of approx. 162 +/- 6 microns at the TMF Coude and approx. 64 +/- 3 microns on the OCD compare to the predicted size range of 52 - 172 microns and 57 - 93 microns, respectively. This is consistent with 4 - 5 arcsec of atmospheric "seeing". The preliminary evaluation of OCD's fine tracking indicates that the uncompensated tracking error is approx. 3.3 micro rad compared to approx. 1.7 micro rad observed in the laboratory. Fine tracking performance was intermittent, primarily due to beacon fades on the OCD tracking sensor. The best bit error rates observed while

  13. Linking algal growth inhibition to chemical activity

    DEFF Research Database (Denmark)

    Schmidt, Stine N.; Mayer, Philipp

    to chemical activity, as opposed to e.g. the total concentration. Baseline toxicity (narcosis) for neutral hydrophobic organic compounds has been shown to initiate in the narrow chemical activity range of 0.01 to 0.1. This presentation focuses on linking algal growth inhibition to chemical activity....... High-quality toxicity data are carefully selected from peer-reviewed scientific literature and QSAR databases. This presentation shows how the chemical activity concept can be used to compare and combine toxicity data across compounds and species in order to characterize toxicity – and further how...

  14. Bidirectional ROF Links with Dynamic Capacity Allocation

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar Chandan , Dharmendra Singh

    2013-10-01

    Full Text Available : Radio over fiber (ROF technology is an integration of wireless and fiber optic network. It plays vital role for broad band wireless communication. The well known advantages of optical as a transmission medium such as low loss, light weight, large bandwidth characteristics, small size and low cable cost make it the ideal and most flexible solution for efficiently transporting radio signals to remotely located antenna site in a wireless network. The joint venture of radio signal and optical fiber technology provides dynamic capacity allocation in radio over fiber links.

  15. Link Label Prediction in Signed Citation Network

    KAUST Repository

    Akujuobi, Uchenna

    2016-04-12

    Link label prediction is the problem of predicting the missing labels or signs of all the unlabeled edges in a network. For signed networks, these labels can either be positive or negative. In recent years, different algorithms have been proposed such as using regression, trust propagation and matrix factorization. These approaches have tried to solve the problem of link label prediction by using ideas from social theories, where most of them predict a single missing label given that labels of other edges are known. However, in most real-world social graphs, the number of labeled edges is usually less than that of unlabeled edges. Therefore, predicting a single edge label at a time would require multiple runs and is more computationally demanding. In this thesis, we look at link label prediction problem on a signed citation network with missing edge labels. Our citation network consists of papers from three major machine learning and data mining conferences together with their references, and edges showing the relationship between them. An edge in our network is labeled either positive (dataset relevant) if the reference is based on the dataset used in the paper or negative otherwise. We present three approaches to predict the missing labels. The first approach converts the label prediction problem into a standard classification problem. We then, generate a set of features for each edge and then adopt Support Vector Machines in solving the classification problem. For the second approach, we formalize the graph such that the edges are represented as nodes with links showing similarities between them. We then adopt a label propagation method to propagate the labels on known nodes to those with unknown labels. In the third approach, we adopt a PageRank approach where we rank the nodes according to the number of incoming positive and negative edges, after which we set a threshold. Based on the ranks, we can infer an edge would be positive if it goes a node above the

  16. Growing Networks with Positive and Negative Links

    Science.gov (United States)

    Dech, Corynne; Antwi, Shadrack; Shaw, Leah

    Scale-free networks grown via preferential attachment have been used to model real-world networks such as the Internet, citation networks, and social networks. Here we investigate signed scale-free networks where an edge represents a positive or negative connection. We present analytic results and simulation for a growing signed network model. We compare the signed network to an unsigned scale-free network. We discuss several options for preferential attachment in a signed network that could be further adapted to model the accumulation of links over time in real-world signed networks.

  17. Cross-linking for microbial keratitis

    Directory of Open Access Journals (Sweden)

    Jayesh Vazirani

    2013-01-01

    Full Text Available The success of collagen cross-linking as a clinical modality to modify the clinical course in keratoconus seems to have fueled the search for alternative applications for this treatment. Current clinical data on its efficacy is limited and laboratory data seems to indicate that it performs poorly against resistant strains of bacteria and against slow growing organisms. However, the biological plausibility of crosslinking and the lack of effective strategies in managing infections with these organisms continue to focus attention on this potential treatment. Well-conducted experimental and clinical studies with controls are required to answer the questions of its efficacy in future.

  18. Singularity links with exotic Stein fillings

    OpenAIRE

    Özbağcı, Burak; Akhmedov, Anar

    2012-01-01

    arXiv:1206.2468v3 [math.GT] 14 May 2014 SINGULARITY LINKS WITH EXOTIC STEIN FILLINGS ANAR AKHMEDOV AND BURAK OZBAGCI ABSTRACT. In [4], it was shown that there exist infinitely many contact Seifert fibered 3-manifolds each of which admits infinitely many exotic (homeomorphic but pairwise non-diffeomorphic) simply-connected Stein fillings. Here we extend this result to a larger set of contact Seifert fibered 3-manifolds with many singular fibers and observe that these 3- ma...

  19. Linked Ocean Data 2.0

    Science.gov (United States)

    Shepherd, Adam; Leadbetter, Adam; Cheatham, Michelle; Thomas, Rob

    2016-04-01

    When considering sustainable development of the oceans, it is not desirable to either have data siloed in one location where it cannot be reused for purposes beyond which it was originally collected, or in a state where it cannot be integrated into an holistic view of the marine environment. As such, the links between datasets should be formally documented and exploited as best as possible. Given this, the use of Semantic Web technology and information modelling patterns are explored with reference to the marine domain. Further, new strategies for adding semantic annotation to data in real-time are discussed and prototyped.

  20. Design and implementation of a fiber optic RS232 link

    Science.gov (United States)

    Ryan, James W.

    1987-09-01

    This thesis investigates the feasibility of using a bi-directional fiber optic link to implement a RS232 data link. The results showed that a fiber optic link is a viable replacement. It offers a bandwidth up to 5 MHz, 250 times that of a RS232 data link. This fiber optic link was tested over a distance of 1.5 kilometers, nearly 100 times that of the present RS232 link. It also offers the benefits of space and weight savings and is comparable to devices produced commercially but at a substantial cost savings.

  1. Crafting Linked Open Data for Cultural Heritage: Mapping and Curation Tools for the Linked Jazz Project

    Directory of Open Access Journals (Sweden)

    M. Cristina Pattuelli

    2013-07-01

    Full Text Available This paper describes tools and methods developed as part of Linked Jazz, a project that uses Linked Open Data (LOD to reveal personal and professional relationships among jazz musicians based on interviews from jazz archives. The overarching aim of Linked Jazz is to explore the possibilities offered by LOD to enhance the visibility of cultural heritage materials and enrich the semantics that describe them. While the full Linked Jazz dataset is still under development, this paper presents two applications that have laid the foundation for the creation of this dataset: the Mapping and Curator Tool, and the Transcript Analyzer. These applications have served primarily for data preparation, analysis, and curation and are representative of the types of tools and methods needed to craft linked data from digital content available on the web. This paper discusses these two domain-agnostic tools developed to create LOD from digital textual documents and offers insight into the process behind the creation of LOD in general.

  2. Characterization of a 450-km Baseline GPS Carrier-Phase Link using an Optical Fiber Link

    CERN Document Server

    Droste, Stefan; Leute, Julia; Raupach, Sebastian M F; Matveev, Arthur; Hänsch, Theodor W; Bauch, Andreas; Holzwarth, Ronald; Grosche, Gesine

    2015-01-01

    A GPS carrier-phase frequency transfer link along a baseline of 450 km has been established and is characterized by comparing it to a phase-stabilized optical fiber link of 920 km length, established between the two endpoints, the Max-Planck-Institut f\\"ur Quantenoptik in Garching and the Physikalisch-Technische Bundesanstalt in Braunschweig. The characterization is accomplished by comparing two active hydrogen masers operated at both institutes. The masers serve as local oscillators and cancel out when the double differences are calculated, such that they do not constitute a limitation for the GPS link characterization. We achieve a frequency instability of 3 x 10^(-13) in 30 s and 5 x 10^(-16) for long averaging times. Frequency comparison results obtained via both links show no deviation larger than the statistical uncertainty of 6 x 10^(-16). These results can be interpreted as a successful cross-check of the measurement uncertainty of a truly remote end fiber link.

  3. Research on common issues for relationship between mechanism degree of freedom, driving link and executive link

    Institute of Scientific and Technical Information of China (English)

    WANG AiLun

    2009-01-01

    During engineering practice and theoretical research, the mechanism degree of freedom is sometimes unequal to the number of the driving link, which is unable to be explained according to the classic theory of the mechanism degree of freedom. To solve this problem, the duality description for operating laws of mechanism is introduced based on the concepts of duality. The Junction-Structure Equation is established for the port descriptions of general ideal mechanism and the functional description for the mechanism degree of freedom is described by utilization of bond graph theory. The force-transfer degree of freedom, i.e. the antithesis concept of movement-transfer degree of freedom, is introduced and defined based on the analysis of energy transfer as well as the analysis of signal causality. By utilization of structural description, functional description and duality description for the equation of degree of freedom, the relationship between the movement-transfer degree of freedom and force-transfer degree of freedom is further explored and analyzed. Thus, the relationship between the mechanism degree of freedom upon the driving link and the executive link is described generally. Finally, some typical relationships between the mechanism degree of freedom, the driving link and the executive link are analyzed.

  4. Porting Initiation and Failure into Linked CHEETAH

    Science.gov (United States)

    Souers, Clark; Vitello, Peter

    2007-06-01

    Linked CHEETAH is a thermo-chemical code coupled to a 2-D hydrocode. Initially, a quadratic-pressure dependent kinetic rate was used, which worked well in modeling prompt detonation of explosives of large size, but does not work on other aspects of explosive behavior. The variable-pressure Tarantula reactive flow rate model was developed with JWL++ in order to also describe failure and initiation, and we have moved this model into Linked CHEETAH. The model works by turning on only above a pressure threshold, where a slow turn-on creates initiation. At a higher pressure, the rate suddenly leaps to a large value over a small pressure range. A slowly failing cylinder will see a rapidly declining rate, which pushes it quickly into failure. At a high pressure, the detonation rate is constant. A sequential validation procedure is used, which includes metal-confined cylinders, rate-sticks, corner-turning, initiation and threshold, gap tests and air gaps. The size (diameter) effect is central to the calibration. This work was performed under the auspices of the U.S. Department of Energy by the University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48.

  5. Parkinson's Disease: The Mitochondria-Iron Link.

    Science.gov (United States)

    Muñoz, Yorka; Carrasco, Carlos M; Campos, Joaquín D; Aguirre, Pabla; Núñez, Marco T

    2016-01-01

    Mitochondrial dysfunction, iron accumulation, and oxidative damage are conditions often found in damaged brain areas of Parkinson's disease. We propose that a causal link exists between these three events. Mitochondrial dysfunction results not only in increased reactive oxygen species production but also in decreased iron-sulfur cluster synthesis and unorthodox activation of Iron Regulatory Protein 1 (IRP1), a key regulator of cell iron homeostasis. In turn, IRP1 activation results in iron accumulation and hydroxyl radical-mediated damage. These three occurrences-mitochondrial dysfunction, iron accumulation, and oxidative damage-generate a positive feedback loop of increased iron accumulation and oxidative stress. Here, we review the evidence that points to a link between mitochondrial dysfunction and iron accumulation as early events in the development of sporadic and genetic cases of Parkinson's disease. Finally, an attempt is done to contextualize the possible relationship between mitochondria dysfunction and iron dyshomeostasis. Based on published evidence, we propose that iron chelation-by decreasing iron-associated oxidative damage and by inducing cell survival and cell-rescue pathways-is a viable therapy for retarding this cycle.

  6. Legendrian links, causality, and the Low conjecture

    CERN Document Server

    Chernov, Vladimir

    2008-01-01

    Let $(X^{m+1}, g)$ be a globally hyperbolic spacetime with Cauchy surface diffeomorphic to an open subset of $\\mathbb R^m$. The Legendrian Low conjecture formulated by Nat\\'ario and Tod says that two events $x,y\\in X$ are causally related if and only if the Legendrian link of spheres $\\mathfrak S_x, \\mathfrak S_y$ whose points are light geodesics passing through $x$ and $y$ is non-trivial in the contact manifold of all light geodesics in $X$. The Low conjecture says that for $m=2$ the events $x,y$ are causally related if and only if $\\mathfrak S_x, \\mathfrak S_y$ is non-trivial as a topological link. We prove the Low and the Legendrian Low conjectures. We also show that similar statements hold for any globally hyperbolic $(X, g)$ such that the universal cover of its Cauchy surface is diffeomorphic to an open domain of $\\mathbb R^m.$

  7. Porting Inition and Failure to Linked Cheetah

    Energy Technology Data Exchange (ETDEWEB)

    Vitello, P; Souers, P C

    2007-07-18

    Linked CHEETAH is a thermo-chemical code coupled to a 2-D hydrocode. Initially, a quadratic-pressure dependent kinetic rate was used, which worked well in modeling prompt detonation of explosives of large size, but does not work on other aspects of explosive behavior. The variable-pressure Tarantula reactive flow rate model was developed with JWL++ in order to also describe failure and initiation, and we have moved this model into Linked CHEETAH. The model works by turning on only above a pressure threshold, where a slow turn-on creates initiation. At a higher pressure, the rate suddenly leaps to a large value over a small pressure range. A slowly failing cylinder will see a rapidly declining rate, which pushes it quickly into failure. At a high pressure, the detonation rate is constant. A sequential validation procedure is used, which includes metal-confined cylinders, rate-sticks, corner-turning, initiation and threshold, gap tests and air gaps. The size (diameter) effect is central to the calibration.

  8. [The link between obesity and cancer].

    Science.gov (United States)

    Sánchez R, César; Ibáñez, Carolina; Klaassen, Julieta

    2014-02-01

    While some genetic factors may explain the development of cancer, its main causes are related to environmental exposure to carcinogenic agents as well as to the effect of determined lifestyles and habits. Several epidemiological studies have shown a consistent relation between obesity and cancer. In non smokers, obesity is the most relevant risk factor in the development of malignant tumors. There is a clear association between obesity and endometrial cancer, breast cancer in postmenopausal women, pancreatic, esophageal and colon cancer. Sexual steroids, insulin like growth factor axis and adipokines are the three main models to explain the biological basis for the obesity-cancer relationship. However, these models do not explain all the biological mechanisms that link obesity to cancer. There are other factors in play such as chronic inflammation, hypoxia and oxidative stress. Obesity may hamper the screening, diagnosis and treatment of some tumors, increasing mortality rates. Obesity prevention and management, therefore, may be the most important modifiable factor in reducing both incidence and mortality in cancer. New studies are required to quantify the effect of intentional weight reduction on the incidence and relapse of cancer. Considering the efficacy of bariatric surgery for weight reduction, it is an attractive model to study this link.

  9. Polychlorinated biphenyls and links to cardiovascular disease.

    Science.gov (United States)

    Perkins, Jordan T; Petriello, Michael C; Newsome, Bradley J; Hennig, Bernhard

    2016-02-01

    The pathology of cardiovascular disease is multi-faceted, with links to many modifiable and non-modifiable risk factors. Epidemiological evidence now implicates exposure to persistent organic pollutants, such as polychlorinated biphenyls (PCBs), with an increased risk of developing diabetes, hypertension, and obesity; all of which are clinically relevant to the onset and progression of cardiovascular disease. PCBs exert their cardiovascular toxicity either directly or indirectly via multiple mechanisms, which are highly dependent on the type and concentration of PCBs present. However, many PCBs may modulate cellular signaling pathways leading to common detrimental outcomes including induction of chronic oxidative stress, inflammation, and endocrine disruption. With the abundance of potential toxic pollutants increasing globally, it is critical to identify sensible means of decreasing associated disease risks. Emerging evidence now implicates a protective role of lifestyle modifications such as increased exercise and/or nutritional modulation via anti-inflammatory foods, which may help to decrease the vascular toxicity of PCBs. This review will outline the current state of knowledge linking coplanar and non-coplanar PCBs to cardiovascular disease and describe the possible molecular mechanism of this association.

  10. Linking obesogenic dysregulation to prostate cancer progression

    Science.gov (United States)

    Taylor, Renea A; Lo, Jennifer; Ascui, Natasha; Watt, Matthew J

    2015-01-01

    The global epidemic of obesity is closely linked to the development of serious co-morbidities, including many forms of cancer. Epidemiological evidence consistently shows that obesity is associated with a similar or mildly increased incidence of prostate cancer but, more prominently, an increased risk for aggressive prostate cancer and prostate cancer-specific mortality. Studies in mice demonstrate that obesity induced by high-fat feeding increases prostate cancer progression; however, the mechanisms underpinning this relationship remain incompletely understood. Adipose tissue expansion in obesity leads to local tissue dysfunction and is associated with low-grade inflammation, alterations in endocrine function and changes in lipolysis that result in increased delivery of fatty acids to tissues of the body. The human prostate gland is covered anteriorly by the prominent peri-prostatic adipose tissue and laterally by smaller adipose tissue depots that lie directly adjacent to the prostatic surface. We discuss how the close association between dysfunctional adipose tissue and prostate epithelial cells might result in bi-directional communication to cause increased prostate cancer aggressiveness and progression. However, the literature indicates that several ‘mainstream’ hypotheses regarding obesity-related drivers of prostate cancer progression are not yet supported by a solid evidence base and, in particular, are not supported by experiments using human tissue. Understanding the links between obesity and prostate cancer will have major implications for the health policy for men with prostate cancer and the development of new therapeutic or preventative strategies. PMID:26581226

  11. Nutrition education: linking research, theory, and practice.

    Science.gov (United States)

    Contento, Isobel R

    2008-01-01

    The increase in obesity and chronic diseases such as diabetes and heart disease worldwide reflects the complex interactions of biology, personal behaviour and environment. Consequently there has been a greater recognition of the importance of nutrition education. An analysis of the evidence from 300+ studies shows that nutrition education is more likely to be effective when it focuses on behaviour/ action (rather than knowledge only) and systematically links theory, research and practice. There are three essential components to nutrition education: 1. A motivational component, where the goal is to increase awareness and enhance motivation by addressing beliefs, attitudes through effective communication strategies. 2. An action component, where the goal is to facilitate people's ability to take action through goal setting and cognitive self-regulation skills. 3. An environmental component, where nutrition educators work with policymakers and others to promote environmental supports for action. Each component needs to be based on appropriate theory and research. The procedure for program design can use the logic model: Inputs are the resources needed as well as the needs analysis process. The outputs are the activities within the three components of nutrition education described above. Here the behavioural focus is selected and theory and research are used to design appropriate educational strategies to achieve the targeted behaviours. The outcomes are the short, medium or long-term impacts of the nutrition program. These are evaluated through the use of appropriate designs and instruments. Nutrition education programs that link research, theory, and practice are more likely to be effective.

  12. Perceptual asymmetries and handedness: A neglected link?

    Directory of Open Access Journals (Sweden)

    Daniele eMarzoli

    2014-02-01

    Full Text Available Healthy individuals tend to weigh in more the left than the right side of visual space in a variety of contexts, ranging from pseudoneglect to perceptual asymmetries for faces. Among the common explanations proposed for the attentional and perceptual advantages of the left visual field, a link with the prevalence of right-handedness in humans has never been suggested, although some evidence seems to converge in favor of a bias of spatial attention towards the region most likely coincident with another person’s right hand during a face-to-face interaction. Such a bias might imply an increased efficiency in monitoring both communicative and aggressive acts, the right limb being more used than the left in both types of behaviour. Although attentional and perceptual asymmetries could be linked to right-handedness at the level of phylogeny because of the evolutionarily advantage of directing attention towards the region where others’ dominant hand usually operates, it is also legitimate to question whether, at the ontogenetic level, frequent exposure to right-handed individuals may foster leftward biases. These views are discussed in the light of extant literature, and a number of tests are proposed in order to assess our hypotheses.

  13. Functional links and robustness in food webs.

    Science.gov (United States)

    Allesina, Stefano; Bodini, Antonio; Pascual, Mercedes

    2009-06-27

    The robustness of ecosystems to species losses is a central question in ecology, given the current pace of extinctions and the many species threatened by human impacts, including habitat destruction and climate change. Robustness from the perspective of secondary extinctions has been addressed in the context of food webs to consider the complex network of species interactions that underlie responses to perturbations. In-silico removal experiments have examined the structural properties of food webs that enhance or hamper the robustness of ecosystems to species losses, with a focus on the role of hubs, the most connected species. Here we take a different approach and focus on the role of the connections themselves. We show that trophic links can be divided into functional and redundant based on their contribution to robustness. The analysis of empirical webs shows that hubs are not necessarily the most important species as they may hold many redundant links. Furthermore, the fraction of functional connections is high and constant across systems regardless of size and interconnectedness. The main consequence of this scaling pattern is that ecosystem robustness can be considerably reduced by species extinctions even when these do not result in any secondary extinctions. This introduces the possibility of tipping points in the collapse of ecosystems.

  14. Linking ecosystem processes to sustainable wetland management

    Science.gov (United States)

    Euliss, Ned H.; Smith, Loren M.; Wilcox, Douglas A.; Browne, Bryant A.

    2009-01-01

    As a result of concern over problems associated with the future of managed wetlands in North America, nearly two dozen wetland scientists and managers met in February 2006 at Bosque del Apache National Wildlife Refuge in New Mexico and discussed a sustainable approach to wetland management. This approach links science with management by focusing on underlying wetland processes. From that meeting, several papers were developed and published in Wetlands to address these concerns (Euliss et al. 2008, Smith et al. 2008, Wilcox 2008). This article summarizes our first paper, Euliss et al. (2008), and a future Newsletter article will summarize Smith et al. (2008). Realization of the role that complex interactions play in maintaining ecosystems, coupled with increasing demands of humans for ecosystem services, has prompted much interest in ecosystem management. Not surprisingly, sustainability of ecosystems has become an explicitly stated goal of many natural resource agencies and, in some cases, has been legislatively mandated to ensure provision of resources for future generations. However, examples of sustainable ecosystem management are uncommon because management goals often focus on specific deliverables rather than processes that sustain ecosystems. This paper has three sections: (1) perspectives in which we provide a bit of history, (2), ecological consequences of a static view, and (3) suggestions to aid wetland managers link management goals with critical ecosystem processes responsible for provision of wetland services.

  15. Links between circadian rhythms and psychiatric disease

    Directory of Open Access Journals (Sweden)

    Ilia N Karatsoreos

    2014-05-01

    Full Text Available Determining the cause of psychiatric disorders is a goal of modern neuroscience, and will hopefully lead to the discovery of treatments to either prevent or alleviate the suffering caused by these diseases. One roadblock to attaining this goal is the realization that neuropsychiatric diseases are rarely due to a single gene polymorphism, environmental exposure, or developmental insult. Rather, it is a complex interaction between these various influences that likely leads to the development of clinically relevant syndromes. Our lab is exploring the links between environmental exposures and neurobehavioral function by investigating how disruption of the circadian (daily clock alters the structure and function of neural circuits, with the hypothesis that disrupting this crucial homeostatic system can directly contribute to altered vulnerability of the organism to other factors that interact to produce psychiatric illness. This review explores some historical and more recent findings that link disrupted circadian clocks to neuropsychiatric disorders, particularly depression, mania, and schizophrenia. We take a comparative approach by exploring the effects observed in human populations, as well as some experimental models used in the laboratory to unravel mechanistic and causal relationships between disruption of the circadian clock and behavioral abnormalities. This is a rich area of research that we predict will contribute greatly to our understanding of how genes, environment, and development interact to modulate an individual’s vulnerability to psychiatric disorders.

  16. Channelopathies linked to plasma membrane phosphoinositides.

    Science.gov (United States)

    Logothetis, Diomedes E; Petrou, Vasileios I; Adney, Scott K; Mahajan, Rahul

    2010-07-01

    The plasma membrane phosphoinositide phosphatidylinositol 4,5-bisphosphate (PIP2) controls the activity of most ion channels tested thus far through direct electrostatic interactions. Mutations in channel proteins that change their apparent affinity to PIP2 can lead to channelopathies. Given the fundamental role that membrane phosphoinositides play in regulating channel activity, it is surprising that only a small number of channelopathies have been linked to phosphoinositides. This review proposes that for channels whose activity is PIP2-dependent and for which mutations can lead to channelopathies, the possibility that the mutations alter channel-PIP2 interactions ought to be tested. Similarly, diseases that are linked to disorders of the phosphoinositide pathway result in altered PIP2 levels. In such cases, it is proposed that the possibility for a concomitant dysregulation of channel activity also ought to be tested. The ever-growing list of ion channels whose activity depends on interactions with PIP2 promises to provide a mechanism by which defects on either the channel protein or the phosphoinositide levels can lead to disease.

  17. Preparing for a Linked Data Enterprise

    Science.gov (United States)

    Hyland, Bernadette

    The cost of building a business application in the early 1990's that was both resilient and could handle additional data sources, let alone third party content, was many times the cost of building a simple application. The use of Web tools and techniques has changed that. The use of Web architecture within enterprises started in the mid-1990's and continues today. The introduction ofWeb architecture within the enterprise has had many benefits which include shortened development cycles, improved product innovation and increased product and service quality. The Semantic Web, a concept introduced in 2000, introduced the concept of machineunderstandable content. The benefit of having computers (or computer programs) understand content is to retrieve and present more relevant information to people. LinkedData, a concept introduced in 2006, is the next evolution and uses the Semantic Web to link related but previously unconnected content in new and meaningful ways. Later chapters in this book discuss both early and current efforts to showcase enterprise data and drive new value and insights.

  18. General relativistic treatment of LISA optical links

    CERN Document Server

    Dhurandhar, S V; Nayak, K Rajesh

    2008-01-01

    LISA is a joint space mission of the NASA and the ESA for detecting low frequency gravitational waves in the band $10^{-5} - 1$ Hz. In order to attain the requisite sensitivity for LISA, the laser frequency noise must be suppressed below the other secondary noises such as the optical path noise, acceleration noise etc. This is achieved by combining time-delayed data for which precise knowledge of time-delays is required. The gravitational field, mainly that of the Sun and the motion of LISA affect the time-delays and the optical links. Further, the effect of the gravitational field of the Earth on the orbits of spacecraft is included. This leads to additional flexing over and above that of the Sun. We have written a numerical code which computes the optical links, that is, the time-delays with great accuracy $\\sim 10^{-2}$ metres - more than what is required for time delay interferometry (TDI) - for most of the orbit and with sufficient accuracy within $\\sim 10$ metres for an integrated time window of about s...

  19. Alpha thalassaemia-mental retardation, X linked

    Directory of Open Access Journals (Sweden)

    Gibbons Richard

    2006-05-01

    Full Text Available Abstract X-linked alpha thalassaemia mental retardation (ATR-X syndrome in males is associated with profound developmental delay, facial dysmorphism, genital abnormalities and alpha thalassaemia. Female carriers are usually physically and intellectually normal. So far, 168 patients have been reported. Language is usually very limited. Seizures occur in about one third of the cases. While many patients are affectionate with their caregivers, some exhibit autistic-like behaviour. Patients present with facial hypotonia and a characteristic mouth. Genital abnormalities are observed in 80% of children and range from undescended testes to ambiguous genitalia. Alpha-thalassaemia is not always present. This syndrome is X-linked recessive and results from mutations in the ATRX gene. This gene encodes the widely expressed ATRX protein. ATRX mutations cause diverse changes in the pattern of DNA methylation at heterochromatic loci but it is not yet known whether this is responsible for the clinical phenotype. The diagnosis can be established by detection of alpha thalassaemia, identification of ATRX gene mutations, ATRX protein studies and X-inactivation studies. Genetic counselling can be offered to families. Management is multidisciplinary: young children must be carefully monitored for gastro-oesophageal reflux as it may cause death. A number of individuals with ATR-X are fit and well in their 30s and 40s.

  20. Simultaneous optical carrier and radio frequency re-modulation in radio-over-fiber systems employing reflective SOA modulators

    DEFF Research Database (Denmark)

    Kassar, Carvalho; Calabretta, Nicola; Tafur Monroy, Idelfonso

    2007-01-01

    We demonstrate an innovative full-duplex radio-over-fibre transmission system employing a reflective SOA to perform simultaneous reusing of the optical carrier and data re-modulation, thus avoiding the use of local radiofrequency oscillator at the station sites.......We demonstrate an innovative full-duplex radio-over-fibre transmission system employing a reflective SOA to perform simultaneous reusing of the optical carrier and data re-modulation, thus avoiding the use of local radiofrequency oscillator at the station sites....