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Sample records for network emulator mne

  1. Introduction to network emulation

    CERN Document Server

    Beuran, Razvan

    2012-01-01

    ""Since network emulation permits investigation of how higher-level protocols interact with the underlying network behaviour, it will be of particular interest to anyone tasked with designing and rolling out new applications and services, especially those aimed at wireless transport. This book represents a comprehensive survey of the current state of the art. It will give the readers a good sense of the various techniques available, allowing them to make an informed decision as to which are appropriate to their particular problem.""-Dr. Neil Davies - Predictable Network Solutions, UK""The Inte

  2. Versatile emulator for automatically switched optical networks

    Science.gov (United States)

    Stilling, Bernd; Nathansen, Martin

    2001-10-01

    Development, testing and deployment of routing and signaling protocols for automatically switched optical networks (ASON) are considerably simplified by using an emulation tool. In this paper we present an emulator that supports OSPF routing and (G)MPLS based signaling. Currently the emulator supports the signaling protocol CR-LDP but we are working on the integration of RSVP-TE. Running complete protocol stacks for each emulated node enables the emulator to fill the gap between a network simulation and a real network. To allow the emulation of very large networks which can not be done on a single workstation the network can be emulated using a set of workstation. By adding additional workstations the number of emulated nodes is almost unlimited. The architecture and the functionality of the emulator are described and an example of an emulation is given. The example network with 16 nodes is investigated regarding the behavior in case of network failures.

  3. The Private and Common Benefits of Spanning Structural Holes within the MNE Network

    DEFF Research Database (Denmark)

    Gärber, Lisa Katarina; Pedersen, Torben; Rogbeer, Shalini

    2012-01-01

    It is well established that spanning structural holes creates private benefits through innovation. However, the extent to which other network members profit from spanning structural holes remains unclear. This research considers how subunits that span structural holes within the MNE network reap...... private benefits in terms of innovation, as well as contribute to the common network benefits through knowledge outflows. Acknowledging that a direct relationship between knowledge sharing and innovation exists, we use a 3SLS model to elucidate the various individual and simultaneous links among brokerage......, innovation and knowledge outflows. In this way, we decompose some of the ways in which brokerage simultaneously affects knowledge outflows and innovation to map out the private and common benefits of brokering within the MNE network. We find that brokerage is indeed positively related to innovation...

  4. Termite: Emulation Testbed for Encounter Networks

    Directory of Open Access Journals (Sweden)

    Rodrigo Bruno

    2015-08-01

    Full Text Available Cutting-edge mobile devices like smartphones and tablets are equipped with various infrastructureless wireless interfaces, such as WiFi Direct and Bluetooth. Such technologies allow for novel mobile applications that take advantage of casual encounters between co-located users. However, the need to mimic the behavior of real-world encounter networks makes testing and debugging of such applications hard tasks. We present Termite, an emulation testbed for encounter networks. Our system allows developers to run their applications on a virtual encounter network emulated by software. Developers can model arbitrary encounter networks and specify user interactions on the emulated virtual devices. To facilitate testing and debugging, developers can place breakpoints, inspect the runtime state of virtual nodes, and run experiments in a stepwise fashion. Termite defines its own Petri Net variant to model the dynamically changing topology and synthesize user interactions with virtual devices. The system is designed to efficiently multiplex an underlying emulation hosting infrastructure across multiple developers, and to support heterogeneous mobile platforms. Our current system implementation supports virtual Android devices communicating over WiFi Direct networks and runs on top of a local cloud infrastructure. We evaluated our system using emulator network traces, and found that Termite is expressive and performs well.

  5. Emulating Wired Backhaul with Wireless Network Coding

    DEFF Research Database (Denmark)

    Thomsen, Henning; De Carvalho, Elisabeth; Popovski, Petar

    2014-01-01

    , the uplink traffic to the user, remains identical to the one performed in a wired system. In the broadcast phase, the decoding of the downlink traffic can also be guaranteed to remain identical. Hence, our solution claims an emulation of a wired backhaul with wireless network coding with same performance. We...

  6. The design of a network emulation and simulation laboratory

    CSIR Research Space (South Africa)

    Von Solms, S

    2015-07-01

    Full Text Available The development of the Network Emulation and Simulation Laboratory is motivated by the drive to contribute to the enhancement of the security and resilience of South Africa's critical information infrastructure. The goal of the Network Emulation...

  7. Emulating Opportunistic Networks with KauNet Triggers

    Directory of Open Access Journals (Sweden)

    Brunstrom Anna

    2011-01-01

    Full Text Available In opportunistic networks, the availability of an end-to-end path is no longer required. Instead opportunistic networks may take advantage of temporary connectivity opportunities. Opportunistic networks present a demanding environment for network emulation as the traditional emulation setup, where application/transport endpoints only send and receive packets from the network following a black box approach, is no longer applicable. Opportunistic networking protocols and applications additionally need to react to the dynamics of the underlying network beyond what is conveyed through the exchange of packets. In order to support IP-level emulation evaluations of applications and protocols that react to lower layer events, we have proposed the use of emulation triggers. Emulation triggers can emulate arbitrary cross-layer feedback and can be synchronized with other emulation effects. After introducing the design and implementation of triggers in the KauNet emulator, we describe the integration of triggers with the DTN2 reference implementation and illustrate how the functionality can be used to emulate a classical DTN data-mule scenario.

  8. On Emulation-Based Network Intrusion Detection Systems

    NARCIS (Netherlands)

    Abbasi, Ali; Wetzel, Jos; Bokslag, Wouter; Zambon, Emmanuele; Etalle, Sandro

    2014-01-01

    Emulation-based network intrusion detection systems have been devised to detect the presence of shellcode in network traffic by trying to execute (portions of) the network packet payloads in an in- strumented environment and checking the execution traces for signs of shellcode activity.

  9. SONEP: A Software-Defined Optical Network Emulation Platform

    DEFF Research Database (Denmark)

    Azodolmolky, Siamak; Petersen, Martin Nordal; Fagertun, Anna Manolova

    2014-01-01

    the lightweight system virtualization, which is recently supported in modern operating systems, in this work we present the architecture of a Software-Defined Network (SDN) emulation platform for transport optical networks and investigate its usage in a use-case scenario. To the best of our knowledge......, this is for the first time that an SDN-based emulation platform is proposed for modeling and performance evaluation of optical networks. Coupled with recent trend of extension of SDN towards transport (optical) networks, the presented tool can facilitate the evaluation of innovative idea before actual implementations...

  10. An overview of Linux container based network emulation

    CSIR Research Space (South Africa)

    Peach, Schalk

    2016-07-01

    Full Text Available Linkletter, 2015 provides reviews of most of the Container-Based Emulators discussed in this paper. The reviews provided are however focused on installation and usage. In contrast, this paper focuses on technical aspects of Container-Based Emulators..., a remote procedure call (RPC) application programming interface (API), a Python library and various user interface (UI) enhancements. Additional goals of the CORE project are to allow wireless network experiments through the Extendable Mobile Ad...

  11. Integration of a network aware traffic generation device into a computer network emulation platform

    CSIR Research Space (South Africa)

    Von Solms, S

    2014-07-01

    Full Text Available Flexible, open source network emulation tools can provide network researchers with significant benefits regarding network behaviour and performance. The evaluation of these networks can benefit greatly from the integration of realistic, network...

  12. Low Cost Network Emulator with Ethernet and E1 Interfaces

    Directory of Open Access Journals (Sweden)

    Zbynek Kocur

    2010-01-01

    Full Text Available Contemporary Next Generation Networks (NGN are mainly built on the Internet Protocol (IP and Ethernet. Major challenge for emerging types of wired and wireless IP-based networks is to provide an adequate Quality of Service (QoS for different services. The quality of evaluation requires a detailed knowledge of the performance requirements for particular services and applications. The paper is primarily oriented to the end-to-end testing for the Ethernet-based terminal equipment. The low cost Ethernet network emulator was developed on the Department of Telecommunication Technology of the Faculty of Electrical Engineering of the Czech Technical University in Prague. The extension for emulation network with the E1 interfaces and TDM over IP transmission can be used with external converters.

  13. Simulated, Emulated, and Physical Investigative Analysis (SEPIA) of networked systems.

    Energy Technology Data Exchange (ETDEWEB)

    Burton, David P.; Van Leeuwen, Brian P.; McDonald, Michael James; Onunkwo, Uzoma A.; Tarman, Thomas David; Urias, Vincent E.

    2009-09-01

    This report describes recent progress made in developing and utilizing hybrid Simulated, Emulated, and Physical Investigative Analysis (SEPIA) environments. Many organizations require advanced tools to analyze their information system's security, reliability, and resilience against cyber attack. Today's security analysis utilize real systems such as computers, network routers and other network equipment, computer emulations (e.g., virtual machines) and simulation models separately to analyze interplay between threats and safeguards. In contrast, this work developed new methods to combine these three approaches to provide integrated hybrid SEPIA environments. Our SEPIA environments enable an analyst to rapidly configure hybrid environments to pass network traffic and perform, from the outside, like real networks. This provides higher fidelity representations of key network nodes while still leveraging the scalability and cost advantages of simulation tools. The result is to rapidly produce large yet relatively low-cost multi-fidelity SEPIA networks of computers and routers that let analysts quickly investigate threats and test protection approaches.

  14. Emulation Platform for Cyber Analysis of Wireless Communication Network Protocols

    Energy Technology Data Exchange (ETDEWEB)

    Van Leeuwen, Brian P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Eldridge, John M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-11-01

    Wireless networking and mobile communications is increasing around the world and in all sectors of our lives. With increasing use, the density and complexity of the systems increase with more base stations and advanced protocols to enable higher data throughputs. The security of data transported over wireless networks must also evolve with the advances in technologies enabling more capable wireless networks. However, means for analysis of the effectiveness of security approaches and implementations used on wireless networks are lacking. More specifically a capability to analyze the lower-layer protocols (i.e., Link and Physical layers) is a major challenge. An analysis approach that incorporates protocol implementations without the need for RF emissions is necessary. In this research paper several emulation tools and custom extensions that enable an analysis platform to perform cyber security analysis of lower layer wireless networks is presented. A use case of a published exploit in the 802.11 (i.e., WiFi) protocol family is provided to demonstrate the effectiveness of the described emulation platform.

  15. On-line Configuration of Network Emulator for Intelligent Energy System Testbed Applications

    DEFF Research Database (Denmark)

    Kemal, Mohammed Seifu; Iov, Florin; Olsen, Rasmus Løvenstein

    2015-01-01

    interface for visualizing, configuring and monitoring of the emulated scenarios and a network socket linking the graphic server and network emulation server on-line. Specifically, our focus area is to build a model that gives us ability to look at some of the challenges on implementing inter...... a mechanism for on-line configuration and monitoring of heterogeneous communication technologies implemented at smart energy system testbed of Aal-borg university. It proposes a model with three main components, a network emulator used to emulate the communication scenarios using KauNet, graphical user...

  16. EmuStack: An OpenStack-Based DTN Network Emulation Platform (Extended Version

    Directory of Open Access Journals (Sweden)

    Haifeng Li

    2016-01-01

    Full Text Available With the advancement of computing and network virtualization technology, the networking research community shows great interest in network emulation. Compared with network simulation, network emulation can provide more relevant and comprehensive details. In this paper, EmuStack, a large-scale real-time emulation platform for Delay Tolerant Network (DTN, is proposed. EmuStack aims at empowering network emulation to become as simple as network simulation. Based on OpenStack, distributed synchronous emulation modules are developed to enable EmuStack to implement synchronous and dynamic, precise, and real-time network emulation. Meanwhile, the lightweight approach of using Docker container technology and network namespaces allows EmuStack to support a (up to hundreds of nodes large-scale topology with only several physical nodes. In addition, EmuStack integrates the Linux Traffic Control (TC tools with OpenStack for managing and emulating the virtual link characteristics which include variable bandwidth, delay, loss, jitter, reordering, and duplication. Finally, experiences with our initial implementation suggest the ability to run and debug experimental network protocol in real time. EmuStack environment would bring qualitative change in network research works.

  17. Simulation Of Networking Protocols On Software Emulated Network Stack

    Directory of Open Access Journals (Sweden)

    Hrushikesh Nimkar

    2015-08-01

    Full Text Available With the increasing number and complexity of network based applications the need to easy configuration development and integration of network applications has taken a high precedence. Trivial activities such as configuration can be carried out efficiently if network services are software based rather than hardware based. Project aims at enabling the network engineers to easily include network functionalities into hisher configuration and define hisher own network stack without using the kernel network stack. Having thought of this we have implemented two functionalities UPNP and MDNS. The multicast Domain Name System MDNS resolves host names to IP addresses within small ad-hoc networks and without having need of special DNS server and its configuration. MDNS application provides every host with functionality to register itself to the router make a multicast DNS request and its resolution. To make adding network devices and networked programs to a network as easy as it is to plug in a piece of hardware into a PC we make use of UPnP. The devices and programs find out about the network setup and other networked devices and programs through discovery and advertisements of services and configure themselves accordingly. UPNP application provides every host with functionality of discovering services of other hosts and serving requests on demand. To implement these applications we have used snabbswitch framework which an open source virtualized ethernet networking stack.

  18. Emulation of realistic network traffic patterns on an eight-node data vortex interconnection network subsystem

    Science.gov (United States)

    Small, Benjamin A.; Shacham, Assaf; Bergman, Keren; Athikulwongse, Krit; Hawkins, Cory; Wills, D. Scott

    2004-11-01

    e demonstrate the feasibility of the data vortex interconnection network architecture for use in supercomputing by emulating realistic network traffic on an eight-node subnetwork. The evaluation workload uses memory accesses from the Barnes-Hut application in the SLPASH-2 parallel computing benchmark suite, which was extracted by using the M5 multiprocessor system simulator. We confirm that traffic is routed correctly and efficiently.

  19. Real Time Emulation of Dynamic Tariff for Congestion Management in Distribution Networks

    DEFF Research Database (Denmark)

    Rasmussen, Theis Bo; Wu, Qiuwei; Huang, Shaojun

    2016-01-01

    This paper presents the real time evaluation of the dynamic tariff (DT) method for alleviating congestion in a distribution networks with high penetration of distributed energy resources (DERs). The DT method is implemented in a real time digital testing platform that emulates a real distribution...

  20. Emulation of the Active Immune Response in a Computer Network

    Science.gov (United States)

    2009-01-15

    there exist a number of methods connected to processes of optimization intended to solve several problems including immunotherapy and immuno ...researchers and security analysts to respond faster in order to keep up with these attacks. New approaches for network security analysis, reactive and

  1. Wireless Visual Sensor Network Robots- Based for the Emulation of Collective Behavior

    Directory of Open Access Journals (Sweden)

    Fredy Hernán Martinez Sarmiento

    2012-03-01

    Full Text Available We consider the problem of bacterial quorum sensing emulate on small mobile robots. Robots that reflect the behavior of bacteria are designed as mobile wireless camera nodes. They are able to structure a dynamic wireless sensor network. Emulated behavior corresponds to a simplification of bacterial quorum sensing, where the action of a network node is conditioned by the population density of robots(nodes in a given area. The population density reading is done visually using a camera. The robot makes an estimate of the population density of the images, and acts according to this information. The operation of the camera is done with a custom firmware, reducing the complexity of the node without loss of performance. It was noted the route planning and the collective behavior of robots without the use of any other external or local communication. Neither was it necessary to develop a model system, precise state estimation or state feedback.

  2. Emulation of reionization simulations for Bayesian inference of astrophysics parameters using neural networks

    Science.gov (United States)

    Schmit, C. J.; Pritchard, J. R.

    2018-03-01

    Next generation radio experiments such as LOFAR, HERA, and SKA are expected to probe the Epoch of Reionization (EoR) and claim a first direct detection of the cosmic 21cm signal within the next decade. Data volumes will be enormous and can thus potentially revolutionize our understanding of the early Universe and galaxy formation. However, numerical modelling of the EoR can be prohibitively expensive for Bayesian parameter inference and how to optimally extract information from incoming data is currently unclear. Emulation techniques for fast model evaluations have recently been proposed as a way to bypass costly simulations. We consider the use of artificial neural networks as a blind emulation technique. We study the impact of training duration and training set size on the quality of the network prediction and the resulting best-fitting values of a parameter search. A direct comparison is drawn between our emulation technique and an equivalent analysis using 21CMMC. We find good predictive capabilities of our network using training sets of as low as 100 model evaluations, which is within the capabilities of fully numerical radiative transfer codes.

  3. Space Link Extension (SLE) Emulation for High-Throughput Network Communication

    Science.gov (United States)

    Murawski, Robert W.; Tchorowski, Nicole; Golden, Bert

    2014-01-01

    As the data rate requirements for space communications increases, significant stress is placed not only on the wireless satellite communication links, but also on the ground networks which forward data from end-users to remote ground stations. These wide area network (WAN) connections add delay and jitter to the end-to-end satellite communication link, effects which can have significant impacts on the wireless communication link. It is imperative that any ground communication protocol can react to these effects such that the ground network does not become a bottleneck in the communication path to the satellite. In this paper, we present our SCENIC Emulation Lab testbed which was developed to test the CCSDS SLE protocol implementations proposed for use on future NASA communication networks. Our results show that in the presence of realistic levels of network delay, high-throughput SLE communication links can experience significant data rate throttling. Based on our observations, we present some insight into why this data throttling happens, and trace the probable issue back to non-optimal blocking communication which is sup-ported by the CCSDS SLE API recommended practices. These issues were presented as well to the SLE implementation developers which, based on our reports, developed a new release for SLE which we show fixes the SLE blocking issue and greatly improves the protocol throughput. In this paper, we also discuss future developments for our end-to-end emulation lab and how these improvements can be used to develop and test future space communication technologies.

  4. Synchronous digital implementation of the AER communication scheme for emulating large-scale spiking neural networks models

    OpenAIRE

    Moreno Aróstegui, Juan Manuel; Madrenas Boadas, Jordi; Kotynia, L.

    2009-01-01

    In this paper we shall present a fully synchronous digital implementation of the Address Event Representation (AER) communication scheme that has been used in the PERPLEXUS chip in order to permit the emulation of large-scale biologically inspired spiking neural networks models. By introducing specific commands in the AER protocol it is possible to distribute the AER bus among a large number of chips where the functionality of the spiking neurons is being emulated. A c...

  5. Application of the dynamically allocated virtual clustering management system to emulated tactical network experimentation

    Science.gov (United States)

    Marcus, Kelvin

    2014-06-01

    The U.S Army Research Laboratory (ARL) has built a "Network Science Research Lab" to support research that aims to improve their ability to analyze, predict, design, and govern complex systems that interweave the social/cognitive, information, and communication network genres. Researchers at ARL and the Network Science Collaborative Technology Alliance (NS-CTA), a collaborative research alliance funded by ARL, conducted experimentation to determine if automated network monitoring tools and task-aware agents deployed within an emulated tactical wireless network could potentially increase the retrieval of relevant data from heterogeneous distributed information nodes. ARL and NS-CTA required the capability to perform this experimentation over clusters of heterogeneous nodes with emulated wireless tactical networks where each node could contain different operating systems, application sets, and physical hardware attributes. Researchers utilized the Dynamically Allocated Virtual Clustering Management System (DAVC) to address each of the infrastructure support requirements necessary in conducting their experimentation. The DAVC is an experimentation infrastructure that provides the means to dynamically create, deploy, and manage virtual clusters of heterogeneous nodes within a cloud computing environment based upon resource utilization such as CPU load, available RAM and hard disk space. The DAVC uses 802.1Q Virtual LANs (VLANs) to prevent experimentation crosstalk and to allow for complex private networks. Clusters created by the DAVC system can be utilized for software development, experimentation, and integration with existing hardware and software. The goal of this paper is to explore how ARL and the NS-CTA leveraged the DAVC to create, deploy and manage multiple experimentation clusters to support their experimentation goals.

  6. Mobi-Sim: An Emulation and Prototyping Platform for Protocols Validation of Mobile Wireless Sensors Networks

    Directory of Open Access Journals (Sweden)

    Omina Mezghani

    2017-01-01

    Full Text Available The objective of this paper is to provide a new simulator framework for mobile WSN that emulate a sensor node at a laptop i.e. the laptop will model and replace a sensor node within a network. This platform can implement different WSN routing protocols to simulate and validate new developed protocols in terms of energy consumption, loss packets rate, delivery ratio, mobility support, connectivity and exchanged messages number in real time. To evaluate the performance of Mobi-Sim, we implement into it two popular protocols (LEACH-M and LEACH sink-mobile and compare its results to TOSSIM. Then, we propose another routing protocol based on clustering that we compare it to LEACH-M.

  7. Programmable chemical reaction networks: emulating regulatory functions in living cells using a bottom-up approach.

    Science.gov (United States)

    van Roekel, Hendrik W H; Rosier, Bas J H M; Meijer, Lenny H H; Hilbers, Peter A J; Markvoort, Albert J; Huck, Wilhelm T S; de Greef, Tom F A

    2015-11-07

    Living cells are able to produce a wide variety of biological responses when subjected to biochemical stimuli. It has become apparent that these biological responses are regulated by complex chemical reaction networks (CRNs). Unravelling the function of these circuits is a key topic of both systems biology and synthetic biology. Recent progress at the interface of chemistry and biology together with the realisation that current experimental tools are insufficient to quantitatively understand the molecular logic of pathways inside living cells has triggered renewed interest in the bottom-up development of CRNs. This builds upon earlier work of physical chemists who extensively studied inorganic CRNs and showed how a system of chemical reactions can give rise to complex spatiotemporal responses such as oscillations and pattern formation. Using purified biochemical components, in vitro synthetic biologists have started to engineer simplified model systems with the goal of mimicking biological responses of intracellular circuits. Emulation and reconstruction of system-level properties of intracellular networks using simplified circuits are able to reveal key design principles and molecular programs that underlie the biological function of interest. In this Tutorial Review, we present an accessible overview of this emerging field starting with key studies on inorganic CRNs followed by a discussion of recent work involving purified biochemical components. Finally, we review recent work showing the versatility of programmable biochemical reaction networks (BRNs) in analytical and diagnostic applications.

  8. Building a multi-FPGA-based emulation framework to support networks-on-chip design and verification

    Science.gov (United States)

    Liu, Yangfan; Liu, Peng; Jiang, Yingtao; Yang, Mei; Wu, Kejun; Wang, Weidong; Yao, Qingdong

    2010-10-01

    In this article, we present a highly scalable, flexible hardware-based network-on-chip (NoC) emulation framework, through which NoCs built upon various types of network topologies, routing algorithms, switching protocols and flow control schemes can be explored, compared, and validated with injected or self-generated traffic from both real-life and synthetic applications. This high degree of scalability and flexibility is achieved due to the field programmable gate array (FPGA) design choices made at both functional and physical levels. At the functional level, a NoC system to be emulated can be partitioned into two parts: (i) the processing cores and (ii) the network. Each part is mapped onto a different FPGA so that when there is any change to be made to any one of these parts, only the corresponding FPGA needs to be reconfigured and the rest of the FPGAs will be left untouched. At the physical level, two levels of interconnects are adopted to mimic NoC on-chip communications: high bandwidth and low latency parallel on-board wires, and high-speed serial multigigabit transceivers available in FPGAs. The latter is particularly important as it helps the proposed NoC emulation platform scale well with the size increase of the NoCs.

  9. Real-Time Emulation of Heterogeneous Wireless Networks with End-to-Edge Quality of Service Guarantees: The AROMA Testbed

    Directory of Open Access Journals (Sweden)

    Anna Umbert

    2010-01-01

    Full Text Available This work presents and describes the real-time testbed for all-IP Beyond 3G (B3G heterogeneous wireless networks that has been developed in the framework of the European IST AROMA project. The main objective of the AROMA testbed is to provide a highly accurate and realistic framework where the performance of algorithms, policies, protocols, services, and applications for a complete heterogeneous wireless network can be fully assessed and evaluated before bringing them to a real system. The complexity of the interaction between all-IP B3G systems and user applications, while dealing with the Quality of Service (QoS concept, motivates the development of this kind of emulation platform where different solutions can be tested in realistic conditions that could not be achieved by means of simple offline simulations. This work provides an in-depth description of the AROMA testbed, emphasizing many interesting implementation details and lessons learned during the development of the tool that may result helpful to other researchers and system engineers in the development of similar emulation platforms. Several case studies are also presented in order to illustrate the full potential and capabilities of the presented emulation platform.

  10. MEG and EEG data analysis with MNE-Python

    National Research Council Canada - National Science Library

    Gramfort, Alexandre; Luessi, Martin; Larson, Eric; Engemann, Denis A; Strohmeier, Daniel; Brodbeck, Christian; Goj, Roman; Jas, Mainak; Brooks, Teon; Parkkonen, Lauri; Hämäläinen, Matti

    2013-01-01

    .... As part of the MNE software suite, MNE-Python is an open-source software package that addresses this challenge by providing state-of-the-art algorithms implemented in Python that cover multiple...

  11. MNE Entrepreneurial Capabilities at Intermediate Levels

    DEFF Research Database (Denmark)

    Hoenen, Anne K.; Nell, Phillip Christopher; Ambos, Björn

    2014-01-01

    This study investigates the entrepreneurial capabilities of MNE units at intermediate geographical levels, between the local subsidiary level and global corporate headquarters. In our conceptual development, we build on the entrepreneurship and MNE embeddedness literature to explain how MNE units...... at intermediate geographical levels differ from local subsidiaries and global corporate headquarters, and why those differences are important. We illustrate our arguments using data on European regional headquarters (RHQs). We find that RHQs' entrepreneurial capabilities depend on their external embeddedness...... and on the heterogeneous information that is generated through dissimilar markets within the region. Our study opens up for an interesting discussion of the independence of these mechanisms. In sum, we contribute to the understanding of the entrepreneurial role of intermediate units in general and RHQs in particular....

  12. Evaluating the Limits of Network Topology Inference Via Virtualized Network Emulation

    Science.gov (United States)

    2015-06-01

    activities from identifying Internet censorship under oppressive regimes and tracking the Internet’s penetration into previously unserved countries and...AVAILABILITY STATEMENT Approved for public release; distribution is unlimited 12b. DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) The Internet ...ability to induce link failures within the network. In addition, this thesis reexamines previous work in sampling Autonomous System-level Internet

  13. Reference Architecture for MNE 5 Technical System

    Science.gov (United States)

    2007-05-30

    Service Definitions Security Authentication Web Service An MNE5 specific service to provide external authentication possibilities. Based on the...Swedish NBD design (FMLS2010). (Ref to doc) LDAP Standard protocol (RFC XXXX) for authentication and authorization. Primarily used for integration... SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18. NUMBER OF PAGES 21 19a. NAME OF RESPONSIBLE PERSON a. REPORT unclassified b

  14. QoS Parameters Evaluation in a VPN-MPLS Diffserv Network under a Complete Free Software Emulation Environment

    Directory of Open Access Journals (Sweden)

    Miroslava Aracely Zapata Rodríguez

    2017-12-01

    Full Text Available The use of Virtual Private Network – Multi Protocol Label Switching (VPN-MPLS networks has become very common inside enterprises thanks to their multiple advantages; such as, the private communication across a public network infrastructure between geographically diverse sites. This leads to a need for an efficient network in terms of Quality of Service (QoS to guarantee reliability and security of information. However, the implementation of a VPN-MPLS network is neither easy nor cheap for small and medium companies; hence, in most cases, it is required the use of emulators that are not free either. In this paper, we analyze a VPN-MPLS network in terms of QoS metrics: delay, jitter and packet loss. This evaluation was performed in a virtual environment using only free software tools under two test scenarios, with and without Differentiated Services (DiffServ. The results showed that a VPN-MPLS DiffServ network reduces the delay by approximately 96.78% in VoIP, 39.21% in Data and 66.83% in Streaming; furthermore, the jitter was reduced by approximately 27.88% in VoIP and 41.09% in Data.

  15. Proposal for an All-Spin Artificial Neural Network: Emulating Neural and Synaptic Functionalities Through Domain Wall Motion in Ferromagnets.

    Science.gov (United States)

    Sengupta, Abhronil; Shim, Yong; Roy, Kaushik

    2016-12-01

    Non-Boolean computing based on emerging post-CMOS technologies can potentially pave the way for low-power neural computing platforms. However, existing work on such emerging neuromorphic architectures have either focused on solely mimicking the neuron, or the synapse functionality. While memristive devices have been proposed to emulate biological synapses, spintronic devices have proved to be efficient at performing the thresholding operation of the neuron at ultra-low currents. In this work, we propose an All-Spin Artificial Neural Network where a single spintronic device acts as the basic building block of the system. The device offers a direct mapping to synapse and neuron functionalities in the brain while inter-layer network communication is accomplished via CMOS transistors. To the best of our knowledge, this is the first demonstration of a neural architecture where a single nanoelectronic device is able to mimic both neurons and synapses. The ultra-low voltage operation of low resistance magneto-metallic neurons enables the low-voltage operation of the array of spintronic synapses, thereby leading to ultra-low power neural architectures. Device-level simulations, calibrated to experimental results, was used to drive the circuit and system level simulations of the neural network for a standard pattern recognition problem. Simulation studies indicate energy savings by  ∼  100× in comparison to a corresponding digital/analog CMOS neuron implementation.

  16. Fractional diffusion emulates a human mobility network during a simulated disease outbreak

    OpenAIRE

    Gustafson, Kyle B; Bayati, Basil S.; Eckhoff, Philip A.

    2016-01-01

    Mobility networks facilitate the growth of populations, the success of invasive species, and the spread of communicable diseases among social animals, including humans. Disease control and elimination efforts, especially during an outbreak, can be optimized by numerical modeling of disease dynamics on transport networks. This is especially true when incidence data from an emerging epidemic is sparse and unreliable. However, mobility networks can be complex, challenging to characterize, and ex...

  17. Neural network emulation of the integral equation model with multiple scattering.

    Science.gov (United States)

    Pulvirenti, Luca; Ticconi, Francesca; Pierdicca, Nazzareno

    2009-01-01

    The Integral Equation Model with multiple scattering (IEMM) represents a well-established method that provides a theoretical framework for the scattering of electromagnetic waves from rough surfaces. A critical aspect is the long computational time required to run such a complex model. To deal with this problem, a neural network technique is proposed in this work. In particular, we have adopted neural networks to reproduce the backscattering coefficients predicted by IEMM at L- and C-bands, thus making reference to presently operative satellite radar sensors, i.e., that aboard ERS-2, ASAR on board ENVISAT (C-band), and PALSAR aboard ALOS (L-band). The neural network-based model has been designed for radar observations of both flat and tilted surfaces, in order to make it applicable for hilly terrains too. The assessment of the proposed approach has been carried out by comparing neural network-derived backscattering coefficients with IEMM-derived ones. Different databases with respect to those employed to train the networks have been used for this purpose. The outcomes seem to prove the feasibility of relying on a neural network approach to efficiently and reliably approximate an electromagnetic model of surface scattering.

  18. Fractional Diffusion Emulates a Human Mobility Network during a Simulated Disease Outbreak

    Directory of Open Access Journals (Sweden)

    Kyle B. Gustafson

    2017-04-01

    Full Text Available Mobility networks facilitate the growth of populations, the success of invasive species, and the spread of communicable diseases among social animals, including humans. Disease control and elimination efforts, especially during an outbreak, can be optimized by numerical modeling of disease dynamics on transport networks. This is especially true when incidence data from an emerging epidemic is sparse and unreliable. However, mobility networks can be complex, challenging to characterize, and expensive to simulate with agent-based models. We therefore studied a parsimonious model for spatiotemporal disease dynamics based on a fractional diffusion equation. We implemented new stochastic simulations of a prototypical influenza-like infection spreading through the United States' highly-connected air travel network. We found that the national-averaged infected fraction during an outbreak is accurately reproduced by a space-fractional diffusion equation consistent with the connectivity of airports. Fractional diffusion therefore seems to be a better model of network outbreak dynamics than a diffusive model. Our fractional reaction-diffusion method and the result could be extended to other mobility networks in a variety of applications for population dynamics.

  19. Wireless Emulation Laboratory

    Data.gov (United States)

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

  20. MEG and EEG data analysis with MNE-Python

    Directory of Open Access Journals (Sweden)

    Alexandre eGramfort

    2013-12-01

    Full Text Available Magnetoencephalography and electroencephalography (M/EEG measure the weakelectromagnetic signals generated by neuronal activity in the brain. Using thesesignals to characterize and locate neural activation in the brain is achallenge that requires expertise in physics, signalprocessing, statistics, and numerical methods. As part of the MNE softwaresuite, MNE-Python is an open-sourcesoftware package that addresses this challenge by providingstate-of-the-art algorithms implemented in Python that cover multiple methods of data preprocessing, source localization, statistical analysis, and estimation offunctional connectivity between distributed brain regions.All algorithms and utility functions are implemented in a consistent manner with well-documented interfaces, enabling users to create M/EEG data analysispipelines by writing Python scripts.Moreover, MNE-Python is tightly integrated with the core Python libraries for scientificcomptutation (Numpy, Scipy and visualization (matplotlib and Mayavi, as wellas the greater neuroimaging ecosystem in Python via the Nibabel package. The code is provided under the new BSD licenseallowing code reuse, even in commercial products. Although MNE-Python has onlybeen under heavy development for a couple of years, it has rapidly evolved withexpanded analysis capabilities and pedagogical tutorials because multiple labs have collaborated during code development to help share best practices.MNE-Python also gives easy access to preprocessed datasets,helping users to get started quickly and facilitating reproducibility ofmethods by other researchers. Full documentation, including dozens ofexamples, is available at http://martinos.org/mne.

  1. Quantum Computer Emulator

    OpenAIRE

    De Raedt, H. A.; Hams, A. H.; Michielsen, K. F. L.; De Raedt, K.

    2000-01-01

    We describe a quantum computer emulator for a generic, general purpose quantum computer. This emulator consists of a simulator of the physical realization of the quantum computer and a graphical user interface to program and control the simulator. We illustrate the use of the quantum computer emulator through various implementations of the Deutsch-Jozsa and Grover's database search algorithm.

  2. MNE Subsidiaries’ Outsourcing and Insourcing of R&D

    DEFF Research Database (Denmark)

    Santangelo, Grazia D.; Meyer, Klaus E.; Jindra, Björn

    2016-01-01

    The rules for business vary not only between countries, but within countries. Subsidiaries of multinational enterprises (MNEs), thus, have to consider both the national level and the local context when designing their business practices. To examine this impact, we study R&D outsourcing in four...... Eastern member states of the European Union and find that local R&D outsourcing is used more frequently where local institutions are strong. However, this local impact depends on the MNE's overall knowledge sourcing practice and is weaker when MNE subsidiaries’ knowledge management prioritizes external...

  3. An advanced real-time digital signal processing system for linear systems emulation, with special emphasis on network and acoustic response characterization

    Science.gov (United States)

    Gaydecki, Patrick; Fernandes, Bosco

    2003-11-01

    A fast digital signal processing (DSP) system is described that can perform real-time emulation of a wide variety of linear audio-bandwidth systems and networks, such as reverberant spaces, musical instrument bodies and very high order filter networks. The hardware design is based upon a Motorola DSP56309 operating at 110 million multiplication-accumulations per second and a dual-channel 24 bit codec with a maximum sampling frequency of 192 kHz. High level software has been developed to express complex vector frequency responses as both infinite impulse response (IIR) and finite impulse response (FIR) coefficients, in a form suitable for real-time convolution by the firmware installed in the DSP system memory. An algorithm has also been devised to express IIR filters as equivalent FIR structures, thereby obviating the potential instabilities associated with recursive equations and negating the traditional deficiencies of FIR filters respecting equivalent analogue designs. The speed and dynamic range of the system is such that, when sampling at 48 kHz, the frequency response can be specified to a spectral precision of 22 Hz when sampling at 10 kHz, this resolution increases to 0.9 Hz. Moreover, it is also possible to control the phase of any frequency band with a theoretical precision of 10-5 degrees in all cases. The system has been applied in the study of analogue filter networks, real-time Hilbert transformation, phase-shift systems and musical instrument body emulation, where it is providing valuable new insights into the understanding of psychoacoustic mechanisms.

  4. A Prolog Emulator

    Science.gov (United States)

    Tick, Evan

    1987-01-01

    This note describes an efficient software emulator for the Warren Abstract Machine (WAM) Prolog architecture. The version of the WAM implemented is called Lcode. The Lcode emulator, written in C, executes the 'naive reverse' benchmark at 3900 LIPS. The emulator is one of a set of tools used to measure the memory-referencing characteristics and performance of Prolog programs. These tools include a compiler, assembler, and memory simulators. An overview of the Lcode architecture is given here, followed by a description and listing of the emulator code implementing each Lcode instruction. This note will be of special interest to those studying the WAM and its performance characteristics. In general, this note will be of interest to those creating efficient software emulators for abstract machine architectures.

  5. Is Brain Emulation Dangerous?

    Science.gov (United States)

    Eckersley, Peter; Sandberg, Anders

    2013-12-01

    Brain emulation is a hypothetical but extremely transformative technology which has a non-zero chance of appearing during the next century. This paper investigates whether such a technology would also have any predictable characteristics that give it a chance of being catastrophically dangerous, and whether there are any policy levers which might be used to make it safer. We conclude that the riskiness of brain emulation probably depends on the order of the preceding research trajectory. Broadly speaking, it appears safer for brain emulation to happen sooner, because slower CPUs would make the technology`s impact more gradual. It may also be safer if brains are scanned before they are fully understood from a neuroscience perspective, thereby increasing the initial population of emulations, although this prediction is weaker and more scenario-dependent. The risks posed by brain emulation also seem strongly connected to questions about the balance of power between attackers and defenders in computer security contests. If economic property rights in CPU cycles1 are essentially enforceable, emulation appears to be comparatively safe; if CPU cycles are ultimately easy to steal, the appearance of brain emulation is more likely to be a destabilizing development for human geopolitics. Furthermore, if the computers used to run emulations can be kept secure, then it appears that making brain emulation technologies ―open‖ would make them safer. If, however, computer insecurity is deep and unavoidable, openness may actually be more dangerous. We point to some arguments that suggest the former may be true, tentatively implying that it would be good policy to work towards brain emulation using open scientific methodology and free/open source software codebases

  6. Emulating I - biomed 2010.

    Science.gov (United States)

    Frenger, Paul

    2010-01-01

    A resting state of consciousness exists in which neural activity, energy consumption and cerebral blood flow are minimized. The author refers to this as i, or little I. In this basal state, there is no internal visual or verbal mental activity, sensory-motor functions are blocked, the executive function is in standby mode and the EEG exhibits theta-alpha band activity. As background, the author describes his experiences as a US Air Force test subject in the 1970s in unpublished training experiments using biofeedback and meditative techniques to control autonomic nervous system functions. The author used this information to extend his computerized human nervous system function emulator (HNSFE), a multitasking IEEE 1275 / Forth language program which imitates the major neural-cognitive operations of the human brain, artificial intelligence, synthetic emotions and somatic control. This program runs on a PC/104 multiprocessor network which includes 8-core 32-bit microprocessors and analog circuit boards to support artificial neural networks, neural membrane substrate-receptor binding simulation, emotional responses and high-level behaviors. The author now moves the executive function i to a separate ARM-based processor board. A waveform generator integrated circuit was also added to create a synthetic EEG signal, whose frequency was varied by a voltage produced by the ARM processor board. The result is a facsimile of the resting state of the conscious brain, instantiated in its own CPU board, generating a simulated EEG, in which the full range of brain functions may be reactivated by voluntary means or by incoming sensory alert.

  7. Immediate response to financial crises : A focus on US MNE subsidiaries

    NARCIS (Netherlands)

    Dikova, D.; Smeets, R.A.; Garretsen, J.H.; van Ees, H.

    2013-01-01

    This paper provides evidence for the immediate or short-term responses to financial crises of US multinational firm (MNE) subsidiaries. Using a real options perspective, we hypothesize that financial crises change the relative value of 'within-country' versus 'across-country' options for MNE

  8. Transnational Diaspora and Civil Society Actors Driving MNE Internationalisation

    DEFF Research Database (Denmark)

    Rana, Mohammad Bakhtiar; Elo, Maria

    2016-01-01

    process. While emerging markets tend to feature complex institutional contexts and idiographic entry challenges, our study with a focus on emerging market presents two under-examined types of stakeholders as distinct social actors’ that affect internationalisation process: the transnational diaspora...... and civil society actors. It provides evidence of the reactive internationalisation of an MNE, showing how the transnational diaspora drove the MNE’s internationalisation and how a civil society actor, in conjunction with a diaspora member, facilitated the creation of an international joint venture (IJV...... that supported this emerging-market IJV development. The study contributes to research on international joint ventures, transnational diaspora entrepreneurship and civil society actors and the internationalisation of MNEs....

  9. MNE subsidiaries' adoption of gender equality and women empowerment goal: a conceptual framework

    National Research Council Canada - National Science Library

    Terpstra-Tong, Jane Lai Yee

    2017-01-01

    This article explores the possible response types of multinational enterprise (MNE) subsidiaries in adopting the gender equality and women empowerment goal, number 5 of the 17 United Nations Sustainable Development Goals...

  10. Nonlinear Source Emulator

    DEFF Research Database (Denmark)

    Nguyen-Duy, Khiem

    and remains the prime source of energy in non-terrestrial applications such as those in sky-explorers. However, a renewable energy source is expensive, bulky, and its performance is weather dependent, which make testing of downstream converters very difficult. As a result, a nonlinear source emulator (NSE...... generator unit. Because nonlinear energy sources come in different sizes and power rating, a single NSE may not be sufficient to simulate a wide selection of nonlinear sources. For this reason, the proposed NSE system is realized as modules. Stacking or connecting multiple modules in parallel will allow...

  11. The concept of radio channel emulator for MANET tests

    Science.gov (United States)

    Kryk, Michał; Łopatka, Jerzy

    2017-04-01

    To provide reliable communications, mobile wireless networks should contain link quality monitoring, adaptive routing and interference avoidance mechanisms. Their efficiency is one of the most critical parameters of the network, so these elements should be robustly designed and thoroughly tested. To minimize time and costs, tests should be performed using a laboratory-based wire test-bed, which would contain devices emulating wireless channels and ensure reproducibility of results. This article presents a concept of an analog and digital radio channel emulator. For the analog radio channel emulator, a method for calculating and setting the attenuation matrix is presented, together with results of the attenuation settings accuracy. For the digital radio channel emulator, the concept of device is presented, along with the calculation method, device control, and preliminary results.

  12. Hardware and Software Integration to Support Real-Time Space-Link Emulation

    Science.gov (United States)

    Murawski, Robert; Bhasin, Kul; Bittner, David

    2012-01-01

    Prior to operational use, communications hardware and software must be thoroughly tested and verified. In space-link communications, field testing equipment can be prohibitively expensive and cannot test to non-ideal situations. In this paper, we show how software and hardware emulation tools can be used to accurately model the characteristics of a satellite communication channel in a lab environment. We describe some of the challenges associated with developing an emulation lab and present results to demonstrate the channel modeling. We then show how network emulation software can be used to extend a hardware emulation model without requiring additional network and channel simulation hardware.

  13. Hardware and Software Integration to Support Real-Time Space Link Emulation

    Science.gov (United States)

    Murawski, Robert; Bhasin, Kul; Bittner, David; Sweet, Aaron; Coulter, Rachel; Schwab, Devin

    2012-01-01

    Prior to operational use, communications hardware and software must be thoroughly tested and verified. In space-link communications, field testing equipment can be prohibitively expensive and cannot test to non-ideal situations. In this paper, we show how software and hardware emulation tools can be used to accurately model the characteristics of a satellite communication channel in a lab environment. We describe some of the challenges associated with developing an emulation lab and present results to demonstrate the channel modeling. We then show how network emulation software can be used to extend a hardware emulation model without requiring additional network and channel simulation hardware.

  14. Photovoltaic sources modeling and emulation

    CERN Document Server

    Piazza, Maria Carmela Di

    2012-01-01

    This book offers an extensive introduction to the modeling of photovoltaic generators and their emulation by means of power electronic converters will aid in understanding and improving design and setup of new PV plants.

  15. Fire Emulator/Detector Evaluator

    Data.gov (United States)

    Federal Laboratory Consortium — Description:The fire emulator/detector evaluator (FE/DE) is a computer-controlled flow tunnel used to re-create the environments surrounding detectors in the early...

  16. RF Emulator Network Channel Emulator for Aeronautical Telemetry Testing

    Science.gov (United States)

    2013-02-20

    SVT e e EMANE N e t w I n t e r Q u e u e P H Y Transport o Q u e u e Q u e u e o o o M A C   /   P NEM NEM Instrumentation R a d i o R a d i o R a...Node CORE a n a g e m e n t Real Node Real Ghost Real Ghost Real Node M a w o r k   r f a c e e SVR SVT e e EMANE Position updates N e t w I n t e r Q...to R Packets N e t w o r k   I n t e r f a c

  17. Evaluating Emulation-based Models of Distributed Computing Systems

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Stephen T. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Cyber Initiatives; Gabert, Kasimir G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Cyber Initiatives; Tarman, Thomas D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Emulytics Initiatives

    2017-08-01

    Emulation-based models of distributed computing systems are collections of virtual ma- chines, virtual networks, and other emulation components configured to stand in for oper- ational systems when performing experimental science, training, analysis of design alterna- tives, test and evaluation, or idea generation. As with any tool, we should carefully evaluate whether our uses of emulation-based models are appropriate and justified. Otherwise, we run the risk of using a model incorrectly and creating meaningless results. The variety of uses of emulation-based models each have their own goals and deserve thoughtful evaluation. In this paper, we enumerate some of these uses and describe approaches that one can take to build an evidence-based case that a use of an emulation-based model is credible. Predictive uses of emulation-based models, where we expect a model to tell us something true about the real world, set the bar especially high and the principal evaluation method, called validation , is comensurately rigorous. We spend the majority of our time describing and demonstrating the validation of a simple predictive model using a well-established methodology inherited from decades of development in the compuational science and engineering community.

  18. Why and how FDI stocks are a biased measure of MNE affiliate activity

    NARCIS (Netherlands)

    Beugelsdijk, S.; Hennart, J.-F.; Slangen, A.; Smeets, R.

    2010-01-01

    Many international business (IB) studies have used foreign direct investment (FDI) stocks to measure the aggregate value-adding activity of multinational enterprises (MNE) affiliates in host countries. We argue that FDI stocks are a biased measure of that activity, because the degree to which they

  19. Why and how FDI stocks are a biased measure of MNE affiliate activity

    NARCIS (Netherlands)

    Beugelsdijk, Sjoerd; Hennart, Jean-Francois; Slangen, Arjen; Smeets, Roger

    2010-01-01

    Many international business (IB) studies have used foreign direct investment (FDI) stocks to measure the aggregate value adding activity of multinational enterprises (MNE) affiliates in host countries We argue that FDI stocks are a biased measure of that activity, because the degree to which they

  20. Intellectual Property Rights and the productivity effects of MNE affiliates on host-country firms

    NARCIS (Netherlands)

    Smeets, R.A.L.M.; Vaal, A. de

    2016-01-01

    In this paper we investigate the impact of increased Intellectual Property Rights (IPR) protection on the productivity effects that MNE affiliates exert on local host-country firms. Conceptually, we argue that IPR protection has two opposing effects: On the one hand, it weakens the productivity

  1. LTE HetNet Mobility Performance Through Emulation with Commercial Smartphones

    DEFF Research Database (Denmark)

    Jensen, Anders Riis; Pedersen, Klaus I.; Lauridsen, Mads

    2014-01-01

    In this paper we introduce a laboratory emulation setup for evaluation of Long Term Evolution (LTE) mobility performance in a co-channel heterogeneous network (HetNet). The setup consists of two eNodeB emulators, signal faders and release 9 LTE User Equipment (UE). It is shown how the LTE HetNet ...

  2. ATM LAN Emulation: Getting from Here to There.

    Science.gov (United States)

    Learn, Larry L., Ed.

    1995-01-01

    Discusses current LAN (local area network) configuration and explains ATM (asynchronous transfer mode) as the future telecommunications transport. Highlights include LAN emulation, which enables the interconnection of legacy LANs and the new ATM environment; virtual LANs; broadcast servers; and standards. (LRW)

  3. A Voltage Mode Memristor Bridge Synaptic Circuit with Memristor Emulators

    Directory of Open Access Journals (Sweden)

    Leon Chua

    2012-03-01

    Full Text Available A memristor bridge neural circuit which is able to perform signed synaptic weighting was proposed in our previous study, where the synaptic operation was verified via software simulation of the mathematical model of the HP memristor. This study is an extension of the previous work advancing toward the circuit implementation where the architecture of the memristor bridge synapse is built with memristor emulator circuits. In addition, a simple neural network which performs both synaptic weighting and summation is built by combining memristor emulators-based synapses and differential amplifier circuits. The feasibility of the memristor bridge neural circuit is verified via SPICE simulations.

  4. W-NINE: A Two-Stage Emulation Platform for Mobile and Wireless Systems

    Directory of Open Access Journals (Sweden)

    Emmanuel Conchon

    2010-01-01

    Full Text Available More and more applications and protocols are now running on wireless networks. Testing the implementation of such applications and protocols is a real challenge as the position of the mobile terminals and environmental effects strongly affect the overall performance. Network emulation is often perceived as a good trade-off between experiments on operational wireless networks and discrete-event simulations on Opnet or ns-2. However, ensuring repeatability and realism in network emulation while taking into account mobility in a wireless environment is very difficult. This paper proposes a network emulation platform, called W-NINE, based on off-line computations preceding online pattern-based traffic shaping. The underlying concepts of repeatability, dynamicity, accuracy, and realism are defined in the emulation context. Two different simple case studies illustrate the validity of our approach with respect to these concepts.

  5. Quantum Emulation of Gravitational Waves.

    Science.gov (United States)

    Fernandez-Corbaton, Ivan; Cirio, Mauro; Büse, Alexander; Lamata, Lucas; Solano, Enrique; Molina-Terriza, Gabriel

    2015-07-14

    Gravitational waves, as predicted by Einstein's general relativity theory, appear as ripples in the fabric of spacetime traveling at the speed of light. We prove that the propagation of small amplitude gravitational waves in a curved spacetime is equivalent to the propagation of a subspace of electromagnetic states. We use this result to propose the use of entangled photons to emulate the evolution of gravitational waves in curved spacetimes by means of experimental electromagnetic setups featuring metamaterials.

  6. Measuring Team Collaboration in a Distributed Coalition Network

    National Research Council Canada - National Science Library

    Bowman, Elizabeth K

    2007-01-01

    ...). Multinational Experiment 4 (MNE 4) provided researchers an opportunity to evaluate how distributed teams interact in a collaborative, networked environment to conduct the Effects Based Approach to Operations (EBAO...

  7. Distributed Emulation in Support of Large Networks

    Science.gov (United States)

    2016-06-01

    series of scripts which can be run automatically as part of the software flow. For example, if DERIK is deploying a topology to a Linux server , it will...ES) Naval Postgraduate School Monterey, CA 93943 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES...Department of Homeland Security 245 Murray Lane SW, Washington, DC 20528 10. SPONSORING / MONITORING AGENCY REPORT NUMBER 11. SUPPLEMENTARY NOTES The

  8. Thermoelectric Generator Emulator for MPPT Testing

    DEFF Research Database (Denmark)

    Man, Elena Anamaria; Sera, Dezso; Máthé, Lászlo

    2015-01-01

    This paper presents a novel approach to use a DC power supply as a thermoelectric generator (TEG) emulator to perform static and dynamic maximum power point tracking (MPPT). First, the electrical characterization of a calcium-manganese-oxide module is performed on a TEG test rig. Afterwards......, the experimentally obtained I-V characteristics of the TEG are emulated using a programmable solar array simulator (SAS). The detailed implementation procedure of the TEG emulator is described. In this work, the SAS has been successfully used to test static and dynamic efficiencies of the MPPT algorithm. For dynamic...

  9. Global Sensitivity analysis of atmospheric chemistry models using emulator-based and emulator-free methods

    Science.gov (United States)

    Ryan, Edmund; Wild, Oliver; O'Connor, Fiona; Voulgarakis, Apostolos; Lee, Lindsay

    2017-04-01

    Carrying out global sensitivity analysis (GSA) for a numerical model is critical in determining which inputs (e.g. parameters, driving data) most affect the model output. This informs us of which inputs to include: (i) for model calibration; (ii) when quantifying the uncertainty in the output given the uncertainty in the inputs. It is also used to diagnose differences in outputs between models. GSA quantifies the sensitivity index (SI) of a particular input - the percentage of the total variability in the output attributed to the changes in that input - by averaging over the other inputs, rather than fixing the other inputs at particular values as done in one-at-a-time sensitivity analysis. Traditional means of computing the SIs involve running the model thousands of times, but this becomes infeasible when the computational cost is high. GSA methods which use a surrogate of the model, called an emulator, are popular as they typically require far fewer runs of the model. Here we consider methods that would further reduce the computational burden of sensitivity analysis. When the output of a model is non-scalar, it is standard practice with an emulator-based GSA method to build a separate emulator for each dimension of the output space. An alternative is to apply principal component analysis (PCA) to reduce the output dimension and then build an emulator for each of the transformed outputs. We consider here a global map of methane lifetimes from our chemistry models. This requires 2000 emulators for the emulator-based GSA methods, but only 10-50 emulators for the PCA-emulator hybrid approach, reducing the computation of the SIs from 1 hour to 3 minutes on a desktop computer. The other benefit of PCA is that the transformed outputs are orthogonal, and thus building separate emulators is appropriate. Results show that very similar maps of SIs are produced whether the emulator-only or emulator-PCA hybrid approach is used. Another avenue to reducing the computational

  10. MNE SPECIFIC FACTORS OF CORPORATE CAPITAL STRUCTURE: COMPARATIVE ANALYSIS IN TERMS OF FINANCIAL RESOURCES DEMAND AND SUPPLY

    Directory of Open Access Journals (Sweden)

    Sergiy Tsyganov

    2015-11-01

    Full Text Available This paper investigates corporate capital structure of multinational enterprises. Its core subject is focused on corporate capital structure defining factors that are specific for MNE rather than for domestic corporations. Substantial part of scientific literature concentrates on country specific and firm specific factors of corporate capital structure with most research devoted to domestic corporations. The main goal of our paper is to discover among plenty of corporate capital structure factors those that are specific for MNE and to develop a new approach for analyzing these factors in terms of financial resources demand and supply. There are some corporate capital structure factors that influence directly and some that have indirect influence while there is also another set of factors having both direct and indirect influence on indebtedness. Different theoretical and empirical research confirm different directions. Methodology of our study is based on analysis of two fundamental market driving forces that are demand and supply. Their influence on corporate capital structure is of a primary origin and that is why the suggested approach is to our mind theoretically significant and practically important. Demand factors imply that a corporation creates demand for financial resources and its capital structure is defined internally. Supply factors imply an external capital structure since it is created by external investors’ supply of financial resources. On empirical level, we use the primary data of corporate financial statements to analyze the leverage of MNE based in different countries and representing different industries. The key results of our study show that the main MNE specific factors of capital structure include such demand factors as multinationality level, assets tangibility and political risk. The first two are firm specific factors that can influence corporate capital structure either directly or indirectly according to

  11. Emulation of Leaf, Canopy and Atmosphere Radiative Transfer Models for Fast Global Sensitivity Analysis

    Directory of Open Access Journals (Sweden)

    Jochem Verrelst

    2016-08-01

    Full Text Available Physically-based radiative transfer models (RTMs help understand the interactions of radiation with vegetation and atmosphere. However, advanced RTMs can be computationally burdensome, which makes them impractical in many real applications, especially when many state conditions and model couplings need to be studied. To overcome this problem, it is proposed to substitute RTMs through surrogate meta-models also named emulators. Emulators approximate the functioning of RTMs through statistical learning regression methods, and can open many new applications because of their computational efficiency and outstanding accuracy. Emulators allow fast global sensitivity analysis (GSA studies on advanced, computationally expensive RTMs. As a proof-of-concept, three machine learning regression algorithms (MLRAs were tested to function as emulators for the leaf RTM PROSPECT-4, the canopy RTM PROSAIL, and the computationally expensive atmospheric RTM MODTRAN5. Selected MLRAs were: kernel ridge regression (KRR, neural networks (NN and Gaussian processes regression (GPR. For each RTM, 500 simulations were generated for training and validation. The majority of MLRAs were excellently validated to function as emulators with relative errors well below 0.2%. The emulators were then put into a GSA scheme and compared against GSA results as generated by original PROSPECT-4 and PROSAIL runs. NN and GPR emulators delivered identical GSA results, while processing speed compared to the original RTMs doubled for PROSPECT-4 and tripled for PROSAIL. Having the emulator-GSA concept successfully tested, for six MODTRAN5 atmospheric transfer functions (outputs, i.e., direct and diffuse at-surface solar irradiance ( E d i f , E d i r , direct and diffuse upward transmittance ( T d i r , T d i f , spherical albedo (S and path radiance ( L 0 , the most accurate MLRA’s were subsequently applied as emulator into the GSA scheme. The sensitivity analysis along the 400–2500 nm

  12. Linking big models to big data: efficient ecosystem model calibration through Bayesian model emulation

    Science.gov (United States)

    Fer, I.; Kelly, R.; Andrews, T.; Dietze, M.; Richardson, A. D.

    2016-12-01

    Our ability to forecast ecosystems is limited by how well we parameterize ecosystem models. Direct measurements for all model parameters are not always possible and inverse estimation of these parameters through Bayesian methods is computationally costly. A solution to computational challenges of Bayesian calibration is to approximate the posterior probability surface using a Gaussian Process that emulates the complex process-based model. Here we report the integration of this method within an ecoinformatics toolbox, Predictive Ecosystem Analyzer (PEcAn), and its application with two ecosystem models: SIPNET and ED2.1. SIPNET is a simple model, allowing application of MCMC methods both to the model itself and to its emulator. We used both approaches to assimilate flux (CO2 and latent heat), soil respiration, and soil carbon data from Bartlett Experimental Forest. This comparison showed that emulator is reliable in terms of convergence to the posterior distribution. A 10000-iteration MCMC analysis with SIPNET itself required more than two orders of magnitude greater computation time than an MCMC run of same length with its emulator. This difference would be greater for a more computationally demanding model. Validation of the emulator-calibrated SIPNET against both the assimilated data and out-of-sample data showed improved fit and reduced uncertainty around model predictions. We next applied the validated emulator method to the ED2, whose complexity precludes standard Bayesian data assimilation. We used the ED2 emulator to assimilate demographic data from a network of inventory plots. For validation of the calibrated ED2, we compared the model to results from Empirical Succession Mapping (ESM), a novel synthesis of successional patterns in Forest Inventory and Analysis data. Our results revealed that while the pre-assimilation ED2 formulation cannot capture the emergent demographic patterns from ESM analysis, constrained model parameters controlling demographic

  13. A Mobile Augmented Reality Emulator for Android

    Directory of Open Access Journals (Sweden)

    Donald Munro

    2017-07-01

    Full Text Available Augmented Reality (AR provides a fusion of the real and virtual worlds by superimposing virtual objects on real world scenery. The implementation of AR on mobile devices is known as Mobile Augmented Reality (MAR. MAR is in its infancy and MAR development software is in the process of maturing. Dating back to the origin of Computer Science as an independent field, software development tools have been an integral part of the process of software creation. MAR, being a relatively new technology, is still lacking such related software development tools. With the rapid progression of mobile devices, the development of MAR applications fusing advanced Computer Vision techniques with mobile device sensors have become increasingly feasible. However, testing and debugging of MAR applications present a new challenge in that they require the developer be at the location that is being augmented at some point during the development process. In this research study, a MAR recorder application was developed as well as emulation class libraries for Android devices that allows the recording and off-site playback of video, location and motion sensor data. The research objective was to provide a software emulator which provides debugging, testing and prototyping capabilities for a MAR application including the ability to emulate the combination of computer vision with locational and motion sensors using previously recorded data. The emulator was evaluated using different mobile technologies. The results indicate that this research could assist developers of MAR applications to implement applications more rapidly, without being at the location.

  14. Hardware Emulation of Wireless Communication Fading Channels

    Science.gov (United States)

    2011-01-01

    2009. [6] Elektrobit, “EB Propsim F8-advanced RF channel emulator,” Online: http://www.elektrobit.com, Jun. 2009. [7] A. Anastasopoulos and K.M. Chugg...digital transmission over WS- SUS channels,” IEEE Trans. Commun., vol. 43, no. 12, pp. 2907-2913, Dec. 1995. [15] A. Anastasopoulos and K.M. Chugg, “An

  15. Dynamic climate emulators for solar geoengineering

    Energy Technology Data Exchange (ETDEWEB)

    MacMartin, Douglas G.; Kravitz, Ben

    2016-12-22

    Climate emulators trained on existing simulations can be used to project project the climate effects that result from different possible future pathways of anthropogenic forcing, without further relying on general circulation model (GCM) simulations. We extend this idea to include different amounts of solar geoengineering in addition to different pathways of greenhouse gas concentrations, by training emulators from a multi-model ensemble of simulations from the Geoengineering Model Intercomparison Project (GeoMIP). The emulator is trained on the abrupt 4 × CO2 and a compensating solar reduction simulation (G1), and evaluated by comparing predictions against a simulated 1 % per year CO2 increase and a similarly smaller solar reduction (G2). We find reasonable agreement in most models for predicting changes in temperature and precipitation (including regional effects), and annual-mean Northern Hemisphere sea ice extent, with the difference between simulation and prediction typically being smaller than natural variability. This verifies that the linearity assumption used in constructing the emulator is sufficient for these variables over the range of forcing considered. Annual-minimum Northern Hemisphere sea ice extent is less well predicted, indicating a limit to the linearity assumption.

  16. Loudspeaker impedance emulator for multi resonant systems

    DEFF Research Database (Denmark)

    Iversen, Niels Elkjær; Knott, Arnold

    2015-01-01

    Specifying the performance of audio amplifiers is typically done by playing sine waves into a pure ohmic load. However real loudspeaker impedances are not purely ohmic but characterised by its electrical, mechanical and acoustical properties. Therefore a loudspeaker emulator capable of adjusting...

  17. Improved photomask metrology through exposure emulation

    Science.gov (United States)

    Potzick, James E.

    1995-07-01

    The ultimate purpose of the photomask in IC manufacture is to define the image to be printed on a silicon wafer. Of the many factors which affect this aerial image in the wafer stepper, some are properties of the stepper projection system and some are properties of the photomask. The purpose of photomask metrology is to help optimize photomask properties to produce the desired aerial image in the stepper. Those factors attributable to the photomask include chrome feature size, phase shifter accuracy (if used), chrome edge roughness and runout, defects, etc. Most of these are usually imaged differently in the exposure tool and the metrology tool because these tools' optical systems are different. Two ways to predict the stepper aerial image from photomask measurements are simulation (modeling) and emulation. In the first, the values of the relevant photomask measurements and properties (if they are known) can be inserted into the models for both tools, and then the stepper aerial image can be predicted from the photomask measurements. Or, the stepper's aerial image of the photomask can be emulated in the metrology tool and magnified for the purpose of measurement. Present mask metrology tools, when used in transmission, duplicate the optical morphology of the projection tool. The projected stepper aerial image can be emulated by adjusting the few major generic optical parameters of the metrology tool to match those of the wafer stepper to be used. Then the measured image in the metrology tool emulates the image in the stepper, and photomask properties affect both images in the same ways. Diverse measurements of photomask characteristics can be made accurately and fast by emulating photomask performance instead of measuring the chrome geometry. All of the significant optical performance parameters of the photomask can be measured with a single tool, at the small expense of shifting to a more appropriate philosophy of mask measurement.

  18. 3D channel emulation in a multi-probe setup

    DEFF Research Database (Denmark)

    Fan, Wei; Sun, Fan; Kyösti, Pekka

    2013-01-01

    A technique to emulate 3D geometry-based channel models in a multiprobe over the air test setup is presented. The proposed technique provides a general emulation framework for any spherical incoming power spectrum. The emulation method results in two optimization objectives, which are both convex...

  19. Emulation tool of dynamic systems via internet

    Directory of Open Access Journals (Sweden)

    Daniel Ruiz Olaya

    2015-11-01

    Full Text Available The experimentation laboratories for the studies of control system courses can become expensive, either in its acquisition, operation or maintenance. An alternative resource have been the remote laboratories. However, not always is possible to get complex systems. A solution to this matter are the remote emulation laboratories. In this paper describes the development of a Web application for the emulation of dynamic systems using a free-distribution software tool of rapid control prototyping based on Linux/RTAI. This application is focused especially for the experimentation with dynamic systems that are not available easily in a laboratory where the model have been configured by the user. The design of the front-end and the back-end are presented. The latency times of the real-time operating system and the ability of the system to reproduce similar signals to a real system from an emulated model were verified. An example, to test the functionality of the application the model of an evaporator was used. One of the advantages of the application is the work methodology which is based on the development of blocks in Scicos. This allows the user to reuse those parameters and the code that was implemented to build a block on the Scicos toolbox with the Linux/RTAI/ScicosLab environment. Moreover, only a web-browser and the Java Virtual Machine are required.

  20. A Novel Floating Memristor Emulator with Minimal Components

    Directory of Open Access Journals (Sweden)

    Zhijun Li

    2017-01-01

    Full Text Available A new floating emulator for the flux-controlled memristor is introduced in this paper. The proposed emulator circuit is very simple and consists of only two current feedback operational amplifiers (CFOAs, two analog multipliers, three resistors, and two capacitors. The emulator can be configured as an incremental or decremental type memristor by using an additional switch. The mathematical model of the emulator is derived to characterize its behavior. The hysteresis behavior of the emulator is discussed in detail, showing that the pinched hysteresis loops in v-i plane depend not only on the amplitude-to-frequency ratio of the exciting signal but also on the time constant of the emulator circuit itself. Experimental tests are provided to validate the emulator’s workability.

  1. Evaluation of Electromechanical Systems Dynamically Emulating a Candidate Hydrokinetic Turbine

    OpenAIRE

    Cavagnaro, R.J.; Neely, J.C.; Faÿ, F.-X.; Lopez-Mendia, J.; Rea, J.A.

    2016-01-01

    Implications of conducting hardware-in-the-loop testing of a specific hydrokinetic turbine on controllable motor-generator sets or electromechanical emulation machines (EEMs)are explored. The emulator control dynamic equations are presented, methods for scaling turbine parameters are developed and evaluated, and experimental results are presented from three EEMs programmed to emulate the same vertical-axis fixed-pitch turbine. Although hardware platforms and control implementations varied, re...

  2. High fidelity imager emulator of measured systems

    Science.gov (United States)

    Haefner, David P.; Teaney, Brian P.

    2017-05-01

    Characterizing an imaging system through the use of linear transfer functions allows prediction of the output for an arbitrary input. Through careful measurement of the systems transfer function, imaging effects can then be applied to desired imagery in order to conduct subjective comparison, image based analysis, or evaluate algorithm performance. The Night Vision Integrated Performance Model (NV-IPM) currently utilizes a two-dimensional linear model of the systems transfer function to emulate the systems response and additive signal independent noise. In this correspondence, we describe how a two-dimensional MTF can be obtained through correct interpolation of one-dimensional measurements. We also present a model for the signal dependent noise (additive and multiplicative) and the details of its calculation from measurement. Through modeling of the experimental setup, we demonstrate how the emulated sensor replicates the observed objective performance in resolution, sampling, and noise. In support of the reproducible research effort, many of the Matlab functions associated with this work can be found on the Mathworks file exchange [1].

  3. An Emulator Toolbox to Approximate Radiative Transfer Models with Statistical Learning

    Directory of Open Access Journals (Sweden)

    Juan Pablo Rivera

    2015-07-01

    Full Text Available Physically-based radiative transfer models (RTMs help in understanding the processes occurring on the Earth’s surface and their interactions with vegetation and atmosphere. When it comes to studying vegetation properties, RTMs allows us to study light interception by plant canopies and are used in the retrieval of biophysical variables through model inversion. However, advanced RTMs can take a long computational time, which makes them unfeasible in many real applications. To overcome this problem, it has been proposed to substitute RTMs through so-called emulators. Emulators are statistical models that approximate the functioning of RTMs. Emulators are advantageous in real practice because of the computational efficiency and excellent accuracy and flexibility for extrapolation. We hereby present an “Emulator toolbox” that enables analysing multi-output machine learning regression algorithms (MO-MLRAs on their ability to approximate an RTM. The toolbox is included in the free-access ARTMO’s MATLAB suite for parameter retrieval and model inversion and currently contains both linear and non-linear MO-MLRAs, namely partial least squares regression (PLSR, kernel ridge regression (KRR and neural networks (NN. These MO-MLRAs have been evaluated on their precision and speed to approximate the soil vegetation atmosphere transfer model SCOPE (Soil Canopy Observation, Photochemistry and Energy balance. SCOPE generates, amongst others, sun-induced chlorophyll fluorescence as the output signal. KRR and NN were evaluated as capable of reconstructing fluorescence spectra with great precision. Relative errors fell below 0.5% when trained with 500 or more samples using cross-validation and principal component analysis to alleviate the underdetermination problem. Moreover, NN reconstructed fluorescence spectra about 50-times faster and KRR about 800-times faster than SCOPE. The Emulator toolbox is foreseen to open new opportunities in the use of advanced

  4. High Dynamic Performance Nonlinear Source Emulator

    DEFF Research Database (Denmark)

    Nguyen-Duy, Khiem; Knott, Arnold; Andersen, Michael A. E.

    2016-01-01

    As research and development of renewable and clean energy based systems is advancing rapidly, the nonlinear source emulator (NSE) is becoming very essential for testing of maximum power point trackers or downstream converters. Renewable and clean energy sources play important roles in both...... terrestrial and nonterrestrial applications. However, most existing NSEs have only been concerned with simulating energy sources in terrestrial applications, which may not be fast enough for testing of nonterrestrial applications. In this paper, a high-bandwidth NSE is developed that is able to simulate...... the behaviors of a typical nonlinear source under different critical conditions that can happen during their operations. The proposed 200-W NSE, which consists of a fourth-order output filter buck converter and a novel nonlinear small-signal reference generator, can quickly react not only to an instantaneous...

  5. An Induction Motor Based Wind Turbine Emulator

    Science.gov (United States)

    Sokolovs, A.; Grigans, L.; Kamolins, E.; Voitkans, J.

    2014-04-01

    The authors present a small-scale wind turbine emulator based on the AC drive system and discuss the methods for power coefficient calculation. In the work, the experimental set-up consisting of an AC induction motor, a frequency converter, a synchronous permanent magnet generator, a DC-DC boost converter and DC load was simulated and tested using real-life equipment. The experimentally obtained wind turbine power and torque diagrams using the emulator are in a good agreement with the theoretical ones. Šajā rakstā parādīta mazas jaudas vēja turbīnas emulatora izveide ar maiņstrāvas piedziņas sistēmu, kā arī analizētas vairākas turbīnas jaudas koeficienta analītiskās aprēķina metodes. Vēja turbīnas emulatora eksperimentālais stends, kas sastāv no asinhronā elektromotora, frekvenču pārveidotāja, sinhronā pastāvīgo magnētu ģeneratora, līdzstrāvas paaugstinošā pārveidotāja un slodzes, tika pārbaudīts gan simulēšanas vidē, gan uz reālām iekārtām. Eksperimentāli iegūtās vēja turbīnas emulatora jaudas un momenta diagrammas ir salīdzinātas ar teorētiskajām.

  6. Quantum emulation of molecular force fields: A blueprint for a superconducting architecture

    Science.gov (United States)

    Olivares, Diego G.; Peropadre, Borja; Huh, Joonsuk; García-Ripoll, Juan José

    We propose a flexible architecture of microwave resonators with tuneable couplings to perform quantum simulations of molecular chemistry problems. The architecture builds on the experience of the D-Wave design, working with nearly harmonic circuits instead of with qubits. This architecture, or modifications of it, can be used to emulate molecular processes such as vibronic transitions. Furthermore, we discuss several aspects of these emulations, such as dynamical ranges of the physical parameters, quenching times necessary for diabaticity and finally the possibility of implementing anharmonic corrections to the force fields by exploiting certain nonlinear features of superconducting devices. Funded by Spanish MINECO Project FIS2015-70856-P, CAM Research Network QUITEMAD+, MINECO FPI Grant BES-2013-066486, Air Force of Scientific Research award FA9550-12-1-0046, NRF of Korea ational Research Foundation of Korea Grant NRF-2015R1A6A3A04059773.

  7. Applying emulators for improved flood risk analysis

    Directory of Open Access Journals (Sweden)

    Malde Sajni

    2016-01-01

    Full Text Available Flood risk analysis often involves the integration of multivariate probability distributions over a domain defined by a consequence function. Often, solutions of this risk integral involves Monte-Carlo sampling techniques, whereby 1000’s of potential flood events are generated. It is necessary to evaluate the consequence of flooding for each sampled event. A significant computational time is required in running flood related physical process models, making it computationally impractical to evaluate flood risk using this approach. To overcome the computational challenges, this paper focusses on the Gaussian Process Emulator (GPE meta-modelling approach. Traditionally, a “look-up table” method is used when a large number of simulations from a numerical model are required. This approach typically involves simulating conditions defined across a regular matrix, and then linearly interpolating intermediate conditions. In this paper we compare a traditional “look-up table” approach to the GPE and analyse their performance in approximating SWAN wave transformation model. In both cases, selecting an appropriate training design set is important and is taken into consideration in the analysis. The analysis shows that the GPE approach requires significantly fewer SWAN runs to obtain similar (or better accuracies, enabling a substantial reduction in computation time, hence aiding the practicality of Monte-Carlo sampling techniques in advanced flood risk modelling.

  8. A Review on the Implementation of Nonlinear Source Emulators

    DEFF Research Database (Denmark)

    Nguyen-Duy, Khiem; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    Renewable energy sources are playing an important role in industry as green sources of energy to reduce carbon dioxide emissions . They possess electrically non linear voltage - current characteristics. In the test and development of the downstream converters that utilize these renewable types...... of energy , the practice of using non linear source emulators instead of the real non linear sources has gained a lot of interest. Differ ent methods of implementing non linear source emulators have been reported in the literature, but no paper exists reviewing and assessing them from different technical...... points of view . This paper provides a review of the implementation of existing non linear source emulators. Their configurations are redrawn as block diagrams and their circuit operations are discussed. Different industrial emulators are also briefly reviewed concerning their features....

  9. RF power consumption emulation optimized with interval valued homotopies

    DEFF Research Database (Denmark)

    Musiige, Deogratius; Anton, François; Yatskevich, Vital

    2011-01-01

    This paper presents a methodology towards the emulation of the electrical power consumption of the RF device during the cellular phone/handset transmission mode using the LTE technology. The emulation methodology takes the physical environmental variables and the logical interface between...... consumption of the RF device operating at 5MHz using homotopy between 2 continuous power consumptions of the RF device operating at the bandwidths 3MHz and 10MHz....

  10. Multiprocessor Priority Ceiling Emulation for Safety-Critical Java

    DEFF Research Database (Denmark)

    Strøm, Torur Biskopstø; Schoeberl, Martin

    2015-01-01

    Priority ceiling emulation has preferable properties on uniprocessor systems, such as avoiding priority inversion and being deadlock free. This has made it a popular locking protocol. According to the safety-critical Java specication, priority ceiling emulation is a requirement for implementations....... However, implementing the protocol for multiprocessor systemsis more complex so implementations might perform worse than non-preemptive implementations. In this paper we compare two multiprocessor lock implementations with hardware support for the Java optimized processor: non-preemptive locking...

  11. Efficient and robust gradient enhanced Kriging emulators.

    Energy Technology Data Exchange (ETDEWEB)

    Dalbey, Keith R.

    2013-08-01

    %E2%80%9CNaive%E2%80%9D or straight-forward Kriging implementations can often perform poorly in practice. The relevant features of the robustly accurate and efficient Kriging and Gradient Enhanced Kriging (GEK) implementations in the DAKOTA software package are detailed herein. The principal contribution is a novel, effective, and efficient approach to handle ill-conditioning of GEK's %E2%80%9Ccorrelation%E2%80%9D matrix, RN%CC%83, based on a pivoted Cholesky factorization of Kriging's (not GEK's) correlation matrix, R, which is a small sub-matrix within GEK's RN%CC%83 matrix. The approach discards sample points/equations that contribute the least %E2%80%9Cnew%E2%80%9D information to RN%CC%83. Since these points contain the least new information, they are the ones which when discarded are both the easiest to predict and provide maximum improvement of RN%CC%83's conditioning. Prior to this work, handling ill-conditioned correlation matrices was a major, perhaps the principal, unsolved challenge necessary for robust and efficient GEK emulators. Numerical results demonstrate that GEK predictions can be significantly more accurate when GEK is allowed to discard points by the presented method. Numerical results also indicate that GEK can be used to break the curse of dimensionality by exploiting inexpensive derivatives (such as those provided by automatic differentiation or adjoint techniques), smoothness in the response being modeled, and adaptive sampling. Development of a suitable adaptive sampling algorithm was beyond the scope of this work; instead adaptive sampling was approximated by omitting the cost of samples discarded by the presented pivoted Cholesky approach.

  12. Case-based reasoning emulation of persons for wheelchair navigation.

    Science.gov (United States)

    Peula, Jose Manuel; Urdiales, Cristina; Herrero, Ignacio; Fernandez-Carmona, Manuel; Sandoval, Francisco

    2012-10-01

    Testing is a key stage in system development, particularly in systems such as a wheelchair, in which the final user is typically a disabled person. These systems have stringent safety requirements, requiring major testing with many different individuals. The best would be to have the wheelchair tested by many different end users, as each disability affects driving skills in a different way. Unfortunately, from a practical point of view it is difficult to engage end users as beta testers. Hence, testing often relies on simulations. Naturally, these simulations need to be as realistic as possible to make the system robust and safe before real tests can be accomplished. This work presents a tool to automatically test wheelchairs through realistic emulation of different wheelchair users. Our approach is based on extracting meaningful data from real users driving a power wheelchair autonomously. This data is then used to train a case-based reasoning (CBR) system that captures the specifics of the driver via learning. The resulting case-base is then used to emulate the driving behavior of that specific person in more complex situations or when a new assistive algorithm needs to be tested. CBR returns user's motion commands appropriate for each specific situation to add the human component to shared control systems. The proposed system has been used to emulate several power wheelchair users presenting different disabilities. Data to create this emulation was obtained from previous wheelchair navigation experiments with 35 volunteer in-patients presenting different degrees of disability. CBR was trained with a limited number of scenarios for each volunteer. Results proved that: (i) emulated and real users returned similar paths in the same scenario (maximum and mean path deviations are equal to 23 and 10cm, respectively) and similar efficiency; (ii) we established the generality of our approach taking a new path not present in the training traces; (iii) the emulated user

  13. The effects of spatial and contextual factors on headquarters resource allocation to MNE subsidiaries

    OpenAIRE

    Henrik Dellestrand; Philip Kappen

    2012-01-01

    Subsidiaries of multinational enterprises are located in a range of environments, in which they are exposed to organizational, national, and sub-national characteristics. Instead of being distributed equally, economic resources are agglomerated in specific countries, or even regions, and the subsidiaries located in these different environments have a heterogeneous resource configuration. This implies that dimensions of space related to geography and subsidiary network relationships may affect...

  14. Automatic Configuration of Programmable Logic Controller Emulators

    Science.gov (United States)

    2015-03-01

    you for your passionate teaching , advice, and mentorship. I would also like to thank the other members in my committee, LTC Mason Rice and Mr. Juan...of words must be built. Second, appropriate grammar must be learned to group and order the words correctly. For network protocols, the equivalent...respective constructs are messages formats (vocabulary) and state machines ( grammar ). Both are required in order for a network protocol to be completely

  15. Emulation: From Digital Artefact to Remotely Rendered Environments

    Directory of Open Access Journals (Sweden)

    Dirk von Suchodoletz

    2009-12-01

    Full Text Available Emulation used as a long-term preservation strategy offers the potential to keep digital objects in their original condition and experience them within their original computer environment. However, having just an emulator in place is not enough. To apply emulation as a fully fledged strategy, an automated and user-friendly approach is required. This cannot be done without knowledge and contextual information of the original software. This paper combines the existing concept of a view path, which captures the contextual information of software, together with new insights into improving the concept with extra metadata. It provides regularly updated instructions for archival management to preserve and access its artefacts. The view-path model requires extensions to the metadata set of the primary object of interest and depends on additionally stored secondary objects for environment recreation like applications or operating systems. This article also addresses a strategy of rendering digital objects by running emulation processes remotely. The advantage of this strategy is that it improves user convenience while maximizing emulation capability.

  16. Emulation with Organic Memristive Devices of Impairment of LTP Mechanism in Neurodegenerative Disease Pathology

    Directory of Open Access Journals (Sweden)

    Silvia Battistoni

    2017-01-01

    Full Text Available We explore and demonstrate the extension of the synapse-mimicking properties of memristive devices to a dysfunctional synapse as it occurs in the Alzheimer’s disease (AD pathology. The ability of memristive devices to reproduce synapse properties such as LTP, LTD, and STDP has been already widely demonstrated, and moreover, they were used for developing artificial neuron networks (perceptrons able to simulate the information transmission in a cell network. However, a major progress would be to extend the common sense of neuromorphic device even to the case of dysfunction of natural synapses. Can memristors efficiently simulate them? We provide here evidences of the ability of emulating the dysfunctional synaptic behavior typical of the AD pathology with organic memristive devices considering the effect of the disease not only on a single synapse but also in the case of a neural network, composed by numerous synapses.

  17. Fast emulation of track reconstruction in the CMS simulation

    CERN Document Server

    Komm, Matthias

    2017-01-01

    Simulated samples of various physics processes are a key ingredient within analyses to unlock the physics behind LHC collision data. Samples with more and more statistics are required to keep up with the increasing amounts of recorded data. During sample generation, significant computing time is spent on the reconstruction of charged particle tracks from energy deposits which additionally scales with the pileup conditions. In CMS, the FastSimulation package is developed for providing a fast alternative to the standard simulation and reconstruction workflow. It employs various techniques to emulate track reconstruction effects in particle collision events. Several analysis groups in CMS are utilizing the package, in particular those requiring many samples to scan the parameter space of physics models (e.g. SUSY) or for the purpose of estimating systematic uncertainties. The strategies for and recent developments in this emulation are presented, including a novel, flexible implementation of tracking emulation w...

  18. Testing Applications in MANET Environments through Emulation

    Directory of Open Access Journals (Sweden)

    Hortelano Jorge

    2009-01-01

    Full Text Available Mobile Ad Hoc Network solution testing is typically done using simulation. The simulated code is generally a simplified version of the real code, and thus code porting to actual operating systems lacks a strong validation. In this work we present Castadiva, a test-bed architecture that allows validating software solutions for real ad hoc network environments using low-cost, off-the-shelf devices and open source software. Castadiva is also compatible with the ns-2 simulator, allowing a combined and more complete evaluation. In this work we present our tool and the results obtained when evaluating videocalls in different scenarios, both static and dynamic.

  19. RF subsystem power consumption and induced radiation emulation

    DEFF Research Database (Denmark)

    Musiige, Deogratius; Anton, François; Mioc, Darka

    the study of the RF subsystem architectures revealed numerous architectures with different impacts on power consumption, we have decided to consider the RF subsystem as a black box. The RF subsystem power emulation has been studied for the telecommunication technology Long Term Evolusion (LTE). Given...

  20. Comparison of Channel Emulation Techniques in Multiprobe Anechoic Chamber Setups

    DEFF Research Database (Denmark)

    Llorente, Ines Carton; Fan, Wei; Nielsen, Jesper Ødum

    2015-01-01

    This paper compares two different techniques for channel emulation in multiprobe anechoic chamber based setups, which is a candidate solution for the standardization of MIMO OTA performance testing of mobile devices. The comparison is performed via simulations of the field distribution, temporal...

  1. Emulating Realistic Bidirectional Spatial Channels for MIMO OTA Testing

    DEFF Research Database (Denmark)

    Fan, Wei; Kyösti, Pekka; Nielsen, Jesper Ødum

    2015-01-01

    This paper discusses over the air (OTA) testing for multiple input multiple output (MIMO) capable terminals with emphasis on modeling bidirectional spatial channel models in multiprobe anechoic chamber (MPAC) setups. In the literature, work on this topic has been mainly focused on how to emulate...

  2. LTE modem power consumption, SAR and RF signal strength emulation

    DEFF Research Database (Denmark)

    Musiige, Deogratius; Vincent, Laulagnet; Anton, François

    2012-01-01

    This paper presents a new methodology for emulating the LTE modem power consumption, emitted SAR and RF signal strength when transmitting an LTE signal. The inputs of the methodology are: modem logical/protocol commands, time advance, near-field specifier, and antenna characteristics. The power...

  3. Physics-based vicinity emulation for enhanced perception in ...

    Indian Academy of Sciences (India)

    A workspace modelling technique, that achieves real-time detection of closeness of robot to workspace object, has been developed by additional physics attribute attachment to workspace. Physics phenomena suiting the realistic work conditions have been identified and a computational model for emulating the ...

  4. Emulating Realistic Bidirectional Spatial Channels for MIMO OTA Testing

    Directory of Open Access Journals (Sweden)

    Wei Fan

    2015-01-01

    Full Text Available This paper discusses over the air (OTA testing for multiple input multiple output (MIMO capable terminals with emphasis on modeling bidirectional spatial channel models in multiprobe anechoic chamber (MPAC setups. In the literature, work on this topic has been mainly focused on how to emulate downlink channel models, whereas uplink channel is often modeled as free space line-of-sight channel without fading. Modeling realistic bidirectional (i.e., both uplink and downlink propagation environments is essential to evaluate any bidirectional communication systems. There have been works stressing the importance of emulating full bidirectional channel and proposing possible directions to implement uplink channels in the literature. Nevertheless, there is no currently published work reporting an experimental validation of such concepts. In this paper, a general framework to emulate bidirectional channels for time division duplexing (TDD and frequency division duplexing (FDD communication systems is proposed. The proposed technique works for MPAC setups with arbitrary uplink and downlink probe configurations, that is, possibly different probe configurations (e.g., number of probes or their configurations in the uplink and downlink. The simulation results are further supported by measurements in a practical MPAC setup. The proposed algorithm is shown to be a valid method to emulate bidirectional spatial channel models.

  5. Single-step emulation of nonlinear fiber-optic link with gaussian mixture model

    DEFF Research Database (Denmark)

    Borkowski, Robert; Doberstein, Andy; Haisch, Hansjörg

    2015-01-01

    We use a fast and low-complexity statistical signal processing method to emulate nonlinear noise in fiber links. The proposed emulation technique stands in good agreement with the numerical NLSE simulation for 32 Gbaud DP-16QAM nonlinear transmission....

  6. Mapping Nordic MNE activities

    DEFF Research Database (Denmark)

    Hansen, Annegrethe; Pedersen, Jørgen Lindgaard

    2006-01-01

    This project has investigated outward foreign direct investments from the Nordic economies, and analysed the role domestic multinational companies play in their respective Nordic home economies. The project consisted of a desktop study of existing research, a quantitative study of FDI flows and t...... activities of such companies provide valuable knowledge inputs into the domestic innovation systems of the Nordic...

  7. Developing a real-time emulation of multiresolutional control architectures for complex, discrete-event systems

    Energy Technology Data Exchange (ETDEWEB)

    Davis, W.J.; Macro, J.G.; Brook, A.L. [Univ. of Illinois, Urbana, IL (United States)] [and others

    1996-12-31

    This paper first discusses an object-oriented, control architecture and then applies the architecture to produce a real-time software emulator for the Rapid Acquisition of Manufactured Parts (RAMP) flexible manufacturing system (FMS). In specifying the control architecture, the coordinated object is first defined as the primary modeling element. These coordinated objects are then integrated into a Recursive, Object-Oriented Coordination Hierarchy. A new simulation methodology, the Hierarchical Object-Oriented Programmable Logic Simulator, is then employed to model the interactions among the coordinated objects. The final step in implementing the emulator is to distribute the models of the coordinated objects over a network of computers and to synchronize their operation to a real-time clock. The paper then introduces the Hierarchical Subsystem Controller as an intelligent controller for the coordinated object. The proposed approach to intelligent control is then compared to the concept of multiresolutional semiosis that has been developed by Dr. Alex Meystel. Finally, the plans for implementing an intelligent controller for the RAMP FMS are discussed.

  8. Hardware emulation of Memristor based Ternary Content Addressable Memory

    KAUST Repository

    Bahloul, Mohamed A.

    2017-12-13

    MTCAM (Memristor Ternary Content Addressable Memory) is a special purpose storage medium in which data could be retrieved based on the stored content. Using Memristors as the main storage element provides the potential of achieving higher density and more efficient solutions than conventional methods. A key missing item in the validation of such approaches is the wide spread availability of hardware emulation platforms that can provide reliable and repeatable performance statistics. In this paper, we present a hardware MTCAM emulation based on 2-Transistors-2Memristors (2T2M) bit-cell. It builds on a bipolar memristor model with storing and fetching capabilities based on the actual current-voltage behaviour. The proposed design offers a flexible verification environment with quick design revisions, high execution speeds and powerful debugging techniques. The proposed design is modeled using VHDL and prototyped on Xilinx Virtex® FPGA.

  9. Simple Floating Voltage-Controlled Memductor Emulator for Analog Applications

    Directory of Open Access Journals (Sweden)

    M. E. Fouda

    2014-09-01

    Full Text Available The topic of memristive circuits is a novel topic in circuit theory that has become of great importance due to its unique behavior which is useful in different applications. But since there is a lack of memristor samples, a memristor emulator is used instead of a solid state memristor. In this paper, a new simple floating voltage-controlled memductor emulator is introduced which is implemented using commercial off the shelf (COTS realization. The mathematical modeling of the proposed circuit is derived to match the theoretical model. The proposed circuit is tested experimentally using different excitation signals such as sinusoidal, square, and triangular waves showing an excellent matching with previously reported simulations.

  10. Memristors with diffusive dynamics as synaptic emulators for neuromorphic computing

    Science.gov (United States)

    Wang, Zhongrui; Joshi, Saumil; Savel'Ev, Sergey E.; Jiang, Hao; Midya, Rivu; Lin, Peng; Hu, Miao; Ge, Ning; Strachan, John Paul; Li, Zhiyong; Wu, Qing; Barnell, Mark; Li, Geng-Lin; Xin, Huolin L.; Williams, R. Stanley; Xia, Qiangfei; Yang, J. Joshua

    2017-01-01

    The accumulation and extrusion of Ca2+ in the pre- and postsynaptic compartments play a critical role in initiating plastic changes in biological synapses. To emulate this fundamental process in electronic devices, we developed diffusive Ag-in-oxide memristors with a temporal response during and after stimulation similar to that of the synaptic Ca2+ dynamics. In situ high-resolution transmission electron microscopy and nanoparticle dynamics simulations both demonstrate that Ag atoms disperse under electrical bias and regroup spontaneously under zero bias because of interfacial energy minimization, closely resembling synaptic influx and extrusion of Ca2+, respectively. The diffusive memristor and its dynamics enable a direct emulation of both short- and long-term plasticity of biological synapses, representing an advance in hardware implementation of neuromorphic functionalities.

  11. COMPUTER EMULATORS AND SIMULATORS OFMEASURING INSTRUMENTS ON THE PHYSICS LESSONS

    Directory of Open Access Journals (Sweden)

    Yaroslav Yu. Dyma

    2010-10-01

    Full Text Available Prominent feature of educational physical experiment at the present stage is applications of computer equipment and special software – virtual measuring instruments. The purpose of this article – to explain, when by means of virtual instruments it is possible to lead real experience (they are emulators, and when – virtual (they are simulators. For the best understanding implementation of one laboratory experimentation with usage of the software of both types is given. As at learning physics advantage should be given to carrying out of natural experiment with learning the real phenomena and measuring of real physical quantities the most perspective examination of programs-emulators of measuring instruments for their further implantation in educational process sees.

  12. Emulation of NFC student card in smart phone

    OpenAIRE

    BEDIČ, MATEJ

    2015-01-01

    In this thesis, we present the implementation of the identification card in a smartphone. We have developed a mobile application that allows emulation of a student card with NFC chip. Thus, instead of plastic NFC card, which is currently in use at the University of Ljubljana, student could use his smartphone for authentication on lectures or tutorials, borrow a book in the library or have access to certain premises of the Faculty. The thesis describes conceptual design and implementation of a...

  13. Real-time high speed generator system emulation with hardware-in-the-loop application

    Science.gov (United States)

    Stroupe, Nicholas

    The emerging emphasis and benefits of distributed generation on smaller scale networks has prompted much attention and focus to research in this field. Much of the research that has grown in distributed generation has also stimulated the development of simulation software and techniques. Testing and verification of these distributed power networks is a complex task and real hardware testing is often desired. This is where simulation methods such as hardware-in-the-loop become important in which an actual hardware unit can be interfaced with a software simulated environment to verify proper functionality. In this thesis, a simulation technique is taken one step further by utilizing a hardware-in-the-loop technique to emulate the output voltage of a generator system interfaced to a scaled hardware distributed power system for testing. The purpose of this thesis is to demonstrate a new method of testing a virtually simulated generation system supplying a scaled distributed power system in hardware. This task is performed by using the Non-Linear Loads Test Bed developed by the Energy Conversion and Integration Thrust at the Center for Advanced Power Systems. This test bed consists of a series of real hardware developed converters consistent with the Navy's All-Electric-Ship proposed power system to perform various tests on controls and stability under the expected non-linear load environment of the Navy weaponry. This test bed can also explore other distributed power system research topics and serves as a flexible hardware unit for a variety of tests. In this thesis, the test bed will be utilized to perform and validate this newly developed method of generator system emulation. In this thesis, the dynamics of a high speed permanent magnet generator directly coupled with a micro turbine are virtually simulated on an FPGA in real-time. The calculated output stator voltage will then serve as a reference for a controllable three phase inverter at the input of the test bed

  14. The Mira-Titan Universe. II. Matter Power Spectrum Emulation

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, Earl; Heitmann, Katrin; Kwan, Juliana; Upadhye, Amol; Bingham, Derek; Habib, Salman; Higdon, David; Pope, Adrian; Finkel, Hal; Frontiere, Nicholas

    2017-09-20

    We introduce a new cosmic emulator for the matter power spectrum covering eight cosmological parameters. Targeted at optical surveys, the emulator provides accurate predictions out to a wavenumber k similar to 5 Mpc(-1) and redshift z <= 2. In addition to covering the standard set of Lambda CDM parameters, massive neutrinos and a dynamical dark energy of state are included. The emulator is built on a sample set of 36 cosmological models, carefully chosen to provide accurate predictions over the wide and large parameter space. For each model, we have performed a high-resolution simulation, augmented with 16 medium-resolution simulations and TimeRG perturbation theory results to provide accurate coverage over a wide k-range; the data set generated as part of this project is more than 1.2Pbytes. With the current set of simulated models, we achieve an accuracy of approximately 4%. Because the sampling approach used here has established convergence and error-control properties, follow-up results with more than a hundred cosmological models will soon achieve similar to 1% accuracy. We compare our approach with other prediction schemes that are based on halo model ideas and remapping approaches.

  15. Approaches for scalable modeling and emulation of cyber systems : LDRD final report.

    Energy Technology Data Exchange (ETDEWEB)

    Mayo, Jackson R.; Minnich, Ronald G.; Armstrong, Robert C.; Rudish, Don W.

    2009-09-01

    The goal of this research was to combine theoretical and computational approaches to better understand the potential emergent behaviors of large-scale cyber systems, such as networks of {approx} 10{sup 6} computers. The scale and sophistication of modern computer software, hardware, and deployed networked systems have significantly exceeded the computational research community's ability to understand, model, and predict current and future behaviors. This predictive understanding, however, is critical to the development of new approaches for proactively designing new systems or enhancing existing systems with robustness to current and future cyber threats, including distributed malware such as botnets. We have developed preliminary theoretical and modeling capabilities that can ultimately answer questions such as: How would we reboot the Internet if it were taken down? Can we change network protocols to make them more secure without disrupting existing Internet connectivity and traffic flow? We have begun to address these issues by developing new capabilities for understanding and modeling Internet systems at scale. Specifically, we have addressed the need for scalable network simulation by carrying out emulations of a network with {approx} 10{sup 6} virtualized operating system instances on a high-performance computing cluster - a 'virtual Internet'. We have also explored mappings between previously studied emergent behaviors of complex systems and their potential cyber counterparts. Our results provide foundational capabilities for further research toward understanding the effects of complexity in cyber systems, to allow anticipating and thwarting hackers.

  16. The emulation theory of representation: motor control, imagery, and perception.

    Science.gov (United States)

    Grush, Rick

    2004-06-01

    The emulation theory of representation is developed and explored as a framework that can revealingly synthesize a wide variety of representational functions of the brain. The framework is based on constructs from control theory (forward models) and signal processing (Kalman filters). The idea is that in addition to simply engaging with the body and environment, the brain constructs neural circuits that act as models of the body and environment. During overt sensorimotor engagement, these models are driven by efference copies in parallel with the body and environment, in order to provide expectations of the sensory feedback, and to enhance and process sensory information. These models can also be run off-line in order to produce imagery, estimate outcomes of different actions, and evaluate and develop motor plans. The framework is initially developed within the context of motor control, where it has been shown that inner models running in parallel with the body can reduce the effects of feedback delay problems. The same mechanisms can account for motor imagery as the off-line driving of the emulator via efference copies. The framework is extended to account for visual imagery as the off-line driving of an emulator of the motor-visual loop. I also show how such systems can provide for amodal spatial imagery. Perception, including visual perception, results from such models being used to form expectations of, and to interpret, sensory input. I close by briefly outlining other cognitive functions that might also be synthesized within this framework, including reasoning, theory of mind phenomena, and language.

  17. Photovoltaic System Test Platform with Integrated Battery Energy Storage Emulator

    DEFF Research Database (Denmark)

    Spataru, Sergiu; Sera, Dezso; Stroe, Daniel-Ioan

    2017-01-01

    In this work, we present a hybrid simulation and a real-time test platform for developing control systems for photovoltaic (PV) inverters with integrated battery energy storage (BES). The platform consists of a dual-stage single-phase PV inverter system, DC coupled with a full-bridge grid connected...... or directly to a physical PV array. The platform enables real-time testing of PV+BES control systems, including battery (BMS) and energy management systems (EMS), for a variety of battery technologies, which can be modelled in detail and emulated by the full-bridge grid connected inverter. Such flexibility...

  18. MCCx C3I Control Center Interface Emulator

    Science.gov (United States)

    Mireles, James R.

    2010-01-01

    This slide presentation reviews the project to develop and demonstrate alternate Information Technologies and systems for new Mission Control Centers that will reduce the cost of facility development, maintenance and operational costs and will enable more efficient cost and effective operations concepts for ground support operations. The development of a emulator for the Control Center capability will enable the facilities to conduct the simulation requiring interactivity with the Control Center when it is off line or unavailable, and it will support testing of C3I interfaces for both command and telemetry data exchange messages (DEMs).

  19. Bayesian sensitivity analysis of a 1D vascular model with Gaussian process emulators.

    Science.gov (United States)

    Melis, Alessandro; Clayton, Richard H; Marzo, Alberto

    2017-12-01

    One-dimensional models of the cardiovascular system can capture the physics of pulse waves but involve many parameters. Since these may vary among individuals, patient-specific models are difficult to construct. Sensitivity analysis can be used to rank model parameters by their effect on outputs and to quantify how uncertainty in parameters influences output uncertainty. This type of analysis is often conducted with a Monte Carlo method, where large numbers of model runs are used to assess input-output relations. The aim of this study was to demonstrate the computational efficiency of variance-based sensitivity analysis of 1D vascular models using Gaussian process emulators, compared to a standard Monte Carlo approach. The methodology was tested on four vascular networks of increasing complexity to analyse its scalability. The computational time needed to perform the sensitivity analysis with an emulator was reduced by the 99.96% compared to a Monte Carlo approach. Despite the reduced computational time, sensitivity indices obtained using the two approaches were comparable. The scalability study showed that the number of mechanistic simulations needed to train a Gaussian process for sensitivity analysis was of the order O(d), rather than O(d×103) needed for Monte Carlo analysis (where d is the number of parameters in the model). The efficiency of this approach, combined with capacity to estimate the impact of uncertain parameters on model outputs, will enable development of patient-specific models of the vascular system, and has the potential to produce results with clinical relevance. © 2017 The Authors International Journal for Numerical Methods in Biomedical Engineering Published by John Wiley & Sons Ltd.

  20. Emulation of a prototype FPGA track finder for the CMS Phase-2 upgrade with the CIDAF emulation framework.

    CERN Document Server

    Amstutz, Christian; Balzer, Matthias Norbert; Brooke, James John; Calligaris, Luigi; Cieri, Davide; Clement, Emyr John; Hall, Geoffrey; Harbaum, Tanja Renate; Harder, Kristian; Hobson, Peter; Iles, Gregory Michiel; James, Thomas Owen; Manolopoulos, Konstantinos; Matsushita, Takashi; Morton, Alexander; Newbold, David; Paramesvaran, Sudarshan; Pesaresi, Mark Franco; Reid, Ivan; Rose, A. W; Sander, Oliver; Schuh, Thomas; Shepherd-Themistocleous, Claire; Shtipliyski, Antoni; Summers, Sioni Paris; Tapper, Alexander; Tomalin, Ian; Uchida, Kirika; Vichoudis, Paschalis; Weber, M

    2016-01-01

    The CMS collaboration is preparing a major upgrade of its detector, so it can operate during the high luminosity run of the LHC from 2026. The upgraded tracker electronics will reconstruct the trajectories of charged particles within a latency of a few microseconds, so that they can be used by the level-1 trigger. An emulation framework, CIDAF, has been developed to provide a reference for a proposed FPGA-based implementation of this track finder, which employs a Time-Multiplexed (TM) technique for data processing.

  1. Dynamical analysis of Parkinsonian state emulated by hybrid Izhikevich neuron models

    Science.gov (United States)

    Liu, Chen; Wang, Jiang; Yu, Haitao; Deng, Bin; Wei, Xile; Li, Huiyan; Loparo, Kenneth A.; Fietkiewicz, Chris

    2015-11-01

    Computational models play a significant role in exploring novel theories to complement the findings of physiological experiments. Various computational models have been developed to reveal the mechanisms underlying brain functions. Particularly, in the development of therapies to modulate behavioral and pathological abnormalities, computational models provide the basic foundations to exhibit transitions between physiological and pathological conditions. Considering the significant roles of the intrinsic properties of the globus pallidus and the coupling connections between neurons in determining the firing patterns and the dynamical activities of the basal ganglia neuronal network, we propose a hypothesis that pathological behaviors under the Parkinsonian state may originate from combined effects of intrinsic properties of globus pallidus neurons and synaptic conductances in the whole neuronal network. In order to establish a computational efficient network model, hybrid Izhikevich neuron model is used due to its capacity of capturing the dynamical characteristics of the biological neuronal activities. Detailed analysis of the individual Izhikevich neuron model can assist in understanding the roles of model parameters, which then facilitates the establishment of the basal ganglia-thalamic network model, and contributes to a further exploration of the underlying mechanisms of the Parkinsonian state. Simulation results show that the hybrid Izhikevich neuron model is capable of capturing many of the dynamical properties of the basal ganglia-thalamic neuronal network, such as variations of the firing rates and emergence of synchronous oscillations under the Parkinsonian condition, despite the simplicity of the two-dimensional neuronal model. It may suggest that the computational efficient hybrid Izhikevich neuron model can be used to explore basal ganglia normal and abnormal functions. Especially it provides an efficient way of emulating the large-scale neuron network

  2. DESIGN AND IMPLEMENTATION OF POTENTIOMETER-BASED NONLINEAR TRANSDUCER EMULATOR

    Directory of Open Access Journals (Sweden)

    Sheroz Khan

    2011-05-01

    Full Text Available This work attempts to design and implement in hardware a transducer with a nonlinear response using potentiometer. Potentiometer is regarded as a linear transducer, while a the response of a nonlinear transducer can be treated as a concatenation of linear segments made out of the response curve of an actual nonlinear transducer at the points of inflections being exhibited by the nonlinear curve. Each straight line segment is characterized by its slope and a constant, called the y-intercept, which is ultimately realized by a corresponding electronic circuit. The complete circuit diagram is made of three stages: (i the input stage for range selection, (ii a digital logic to make appropriate selection, (iii a conditioning circuit for realizing a given straight-line segment identified by its relevant slope and reference voltage. The simulation of the circuit is carried using MULTISIM, and the designed circuit is afterward tested to verify that variations of the input voltage give us an output voltage very close to the response pattern envisaged in the analytical stage of the design. The utility of this work lies in its applications in emulating purpose built transducers that could be used to nicely emulate a transducer in a real world system that is to be controlled by a programmable digital system.

  3. Connecting the Brain to Itself through an Emulation

    Directory of Open Access Journals (Sweden)

    Mijail D. Serruya

    2017-06-01

    Full Text Available Pilot clinical trials of human patients implanted with devices that can chronically record and stimulate ensembles of hundreds to thousands of individual neurons offer the possibility of expanding the substrate of cognition. Parallel trains of firing rate activity can be delivered in real-time to an array of intermediate external modules that in turn can trigger parallel trains of stimulation back into the brain. These modules may be built in software, VLSI firmware, or biological tissue as in vitro culture preparations or in vivo ectopic construct organoids. Arrays of modules can be constructed as early stage whole brain emulators, following canonical intra- and inter-regional circuits. By using machine learning algorithms and classic tasks known to activate quasi-orthogonal functional connectivity patterns, bedside testing can rapidly identify ensemble tuning properties and in turn cycle through a sequence of external module architectures to explore which can causatively alter perception and behavior. Whole brain emulation both (1 serves to augment human neural function, compensating for disease and injury as an auxiliary parallel system, and (2 has its independent operation bootstrapped by a human-in-the-loop to identify optimal micro- and macro-architectures, update synaptic weights, and entrain behaviors. In this manner, closed-loop brain-computer interface pilot clinical trials can advance strong artificial intelligence development and forge new therapies to restore independence in children and adults with neurological conditions.

  4. Connecting the Brain to Itself through an Emulation.

    Science.gov (United States)

    Serruya, Mijail D

    2017-01-01

    Pilot clinical trials of human patients implanted with devices that can chronically record and stimulate ensembles of hundreds to thousands of individual neurons offer the possibility of expanding the substrate of cognition. Parallel trains of firing rate activity can be delivered in real-time to an array of intermediate external modules that in turn can trigger parallel trains of stimulation back into the brain. These modules may be built in software, VLSI firmware, or biological tissue as in vitro culture preparations or in vivo ectopic construct organoids. Arrays of modules can be constructed as early stage whole brain emulators, following canonical intra- and inter-regional circuits. By using machine learning algorithms and classic tasks known to activate quasi-orthogonal functional connectivity patterns, bedside testing can rapidly identify ensemble tuning properties and in turn cycle through a sequence of external module architectures to explore which can causatively alter perception and behavior. Whole brain emulation both (1) serves to augment human neural function, compensating for disease and injury as an auxiliary parallel system, and (2) has its independent operation bootstrapped by a human-in-the-loop to identify optimal micro- and macro-architectures, update synaptic weights, and entrain behaviors. In this manner, closed-loop brain-computer interface pilot clinical trials can advance strong artificial intelligence development and forge new therapies to restore independence in children and adults with neurological conditions.

  5. The Ghost Condition: Imitation Versus Emulation in Young Children's Observational Learning.

    Science.gov (United States)

    Thompson, Doreen E.; Russell, James

    2004-01-01

    Although observational learning by children may occur through imitating a modeler's actions, it can also occur through learning about an object's dynamic affordances- a process that M. Tomasello (1996) calls "emulation." The relative contributions of imitation and emulation within observational learning were examined in a study with 14- to…

  6. A Device to Emulate Diffusion and Thermal Conductivity Using Water Flow

    Science.gov (United States)

    Blanck, Harvey F.

    2005-01-01

    A device designed to emulate diffusion and thermal conductivity using flowing water is reviewed. Water flowing through a series of cells connected by a small tube in each partition in this plastic model is capable of emulating diffusion and thermal conductivity that occurs in variety of systems described by several mathematical equations.

  7. Biorobotics: using robots to emulate and investigate agile locomotion.

    Science.gov (United States)

    Ijspeert, Auke J

    2014-10-10

    The graceful and agile movements of animals are difficult to analyze and emulate because locomotion is the result of a complex interplay of many components: the central and peripheral nervous systems, the musculoskeletal system, and the environment. The goals of biorobotics are to take inspiration from biological principles to design robots that match the agility of animals, and to use robots as scientific tools to investigate animal adaptive behavior. Used as physical models, biorobots contribute to hypothesis testing in fields such as hydrodynamics, biomechanics, neuroscience, and prosthetics. Their use may contribute to the design of prosthetic devices that more closely take human locomotion principles into account. Copyright © 2014, American Association for the Advancement of Science.

  8. Programming a Detector Emulator on NI's FlexRIO Platform

    Science.gov (United States)

    Gervais, Michelle; Crawford, Christopher; Sprow, Aaron; Nab Collaboration

    2017-09-01

    Recently digital detector emulators have been on the rise as a means to test data acquisition systems and analysis toolkits from a well understood data set. National Instruments' PXIe-7962R FPGA module and Active Technologies AT-1212 DAC module provide a customizable platform for analog output. Using a graphical programming language, we have developed a system capable of producing two time-correlated channels of analog output which sample unique amplitude spectra to mimic nuclear physics experiments. This system will be used to model the Nab experiment, in which a prompt beta decay electron is followed by a slow proton according to a defined time distribution. We will present the results of our work and discuss further development potential. DOE under Contract DE-SC0008107.

  9. Brexit and Euroscepticism: Will 'Leaving Europe' be Emulated Elsewhere?

    DEFF Research Database (Denmark)

    Wind, Marlene

    2017-01-01

    Centerleder og professor på Center for Europæisk Politik Marlene Wind har bidraget til den nye udgivelse ”The Law & Politics of Brexit”, der er redigeret af professor Federico Fabbrini.Kapitlet i bogen, som Marlene Wind har bidraget med, bærer titlen: ”Brexit and Euroscepticism: Will 'Leaving...... Europe' be Emulated Elsewhere?” Kapitet giver sig således i kast med, at undersøge mekanismerne i den påståede bølge af euroskeptisme, som historikeren Anne Applebaum forudsagde ville ødelægge det europæiske samarbejde. Bidraget konkluderer, at det er svært at se tegn på, at brexit-effekten sker andre...

  10. An FPGA-Based Quantum Computing Emulation Framework Based on Serial-Parallel Architecture

    Directory of Open Access Journals (Sweden)

    Y. H. Lee

    2016-01-01

    Full Text Available Hardware emulation of quantum systems can mimic more efficiently the parallel behaviour of quantum computations, thus allowing higher processing speed-up than software simulations. In this paper, an efficient hardware emulation method that employs a serial-parallel hardware architecture targeted for field programmable gate array (FPGA is proposed. Quantum Fourier transform and Grover’s search are chosen as case studies in this work since they are the core of many useful quantum algorithms. Experimental work shows that, with the proposed emulation architecture, a linear reduction in resource utilization is attained against the pipeline implementations proposed in prior works. The proposed work contributes to the formulation of a proof-of-concept baseline FPGA emulation framework with optimization on datapath designs that can be extended to emulate practical large-scale quantum circuits.

  11. Emulation of recharge and evapotranspiration processes in shallow groundwater systems

    Science.gov (United States)

    Doble, Rebecca C.; Pickett, Trevor; Crosbie, Russell S.; Morgan, Leanne K.; Turnadge, Chris; Davies, Phil J.

    2017-12-01

    In shallow groundwater systems, recharge and evapotranspiration are highly sensitive to changes in the depth to water table. To effectively model these fluxes, complex functions that include soil and vegetation properties are often required. Model emulation (surrogate modelling or meta-modelling) can provide a means of incorporating detailed conceptualisation of recharge and evapotranspiration processes, while maintaining the numerical tractability and computational performance required for regional scale groundwater models and uncertainty analysis. A method for emulating recharge and evapotranspiration processes in groundwater flow models was developed, and applied to the South East region of South Australia and western Victoria, which is characterised by shallow groundwater, wetlands and coastal lakes. The soil-vegetation-atmosphere transfer (SVAT) model WAVES was used to generate relationships between net recharge (diffuse recharge minus evapotranspiration from groundwater) and depth to water table for different combinations of climate, soil and land cover types. These relationships, which mimicked previously described soil, vegetation and groundwater behaviour, were combined into a net recharge lookup table. The segmented evapotranspiration package in MODFLOW was adapted to select values of net recharge from the lookup table depending on groundwater depth, and the climate, soil and land use characteristics of each cell. The model was found to be numerically robust in steady state testing, had no major increase in run time, and would be more efficient than tightly-coupled modelling approaches. It made reasonable predictions of net recharge and groundwater head compared with remotely sensed estimates of net recharge and a standard MODFLOW comparison model. In particular, the method was better able to predict net recharge and groundwater head in areas with steep hydraulic gradients.

  12. Emulation-Based Virtual Laboratories: A Low-Cost Alternative to Physical Experiments in Control Engineering Education

    Science.gov (United States)

    Goodwin, G. C.; Medioli, A. M.; Sher, W.; Vlacic, L. B.; Welsh, J. S.

    2011-01-01

    This paper argues the case for emulation-based virtual laboratories in control engineering education. It demonstrates that such emulation experiments can give students an industrially relevant educational experience at relatively low cost. The paper also describes a particular emulation-based system that has been developed with the aim of giving…

  13. Demonstration of Emulator-Based Bayesian Calibration of Safety Analysis Codes: Theory and Formulation

    Directory of Open Access Journals (Sweden)

    Joseph P. Yurko

    2015-01-01

    Full Text Available System codes for simulation of safety performance of nuclear plants may contain parameters whose values are not known very accurately. New information from tests or operating experience is incorporated into safety codes by a process known as calibration, which reduces uncertainty in the output of the code and thereby improves its support for decision-making. The work reported here implements several improvements on classic calibration techniques afforded by modern analysis techniques. The key innovation has come from development of code surrogate model (or code emulator construction and prediction algorithms. Use of a fast emulator makes the calibration processes used here with Markov Chain Monte Carlo (MCMC sampling feasible. This work uses Gaussian Process (GP based emulators, which have been used previously to emulate computer codes in the nuclear field. The present work describes the formulation of an emulator that incorporates GPs into a factor analysis-type or pattern recognition-type model. This “function factorization” Gaussian Process (FFGP model allows overcoming limitations present in standard GP emulators, thereby improving both accuracy and speed of the emulator-based calibration process. Calibration of a friction-factor example using a Method of Manufactured Solution is performed to illustrate key properties of the FFGP based process.

  14. Feasibility of neuro-morphic computing to emulate error-conflict based decision making.

    Energy Technology Data Exchange (ETDEWEB)

    Branch, Darren W.

    2009-09-01

    A key aspect of decision making is determining when errors or conflicts exist in information and knowing whether to continue or terminate an action. Understanding the error-conflict processing is crucial in order to emulate higher brain functions in hardware and software systems. Specific brain regions, most notably the anterior cingulate cortex (ACC) are known to respond to the presence of conflicts in information by assigning a value to an action. Essentially, this conflict signal triggers strategic adjustments in cognitive control, which serve to prevent further conflict. The most probable mechanism is the ACC reports and discriminates different types of feedback, both positive and negative, that relate to different adaptations. Unique cells called spindle neurons that are primarily found in the ACC (layer Vb) are known to be responsible for cognitive dissonance (disambiguation between alternatives). Thus, the ACC through a specific set of cells likely plays a central role in the ability of humans to make difficult decisions and solve challenging problems in the midst of conflicting information. In addition to dealing with cognitive dissonance, decision making in high consequence scenarios also relies on the integration of multiple sets of information (sensory, reward, emotion, etc.). Thus, a second area of interest for this proposal lies in the corticostriatal networks that serve as an integration region for multiple cognitive inputs. In order to engineer neurological decision making processes in silicon devices, we will determine the key cells, inputs, and outputs of conflict/error detection in the ACC region. The second goal is understand in vitro models of corticostriatal networks and the impact of physical deficits on decision making, specifically in stressful scenarios with conflicting streams of data from multiple inputs. We will elucidate the mechanisms of cognitive data integration in order to implement a future corticostriatal-like network in silicon

  15. Hardware Locks with Priority Ceiling Emulation for a Java Chip-Multiprocessor

    DEFF Research Database (Denmark)

    Strøm, Torur Biskopstø; Schoeberl, Martin

    2015-01-01

    According to the safety-critical Java specification, priority ceiling emulation is a requirement for implementations, as it has preferable properties, such as avoiding priority inversion and being deadlock free on uni-core systems. In this paper we explore our hardware supported implementation...... of priority ceiling emulation on the multicore Java optimized processor, and compare it to the existing hardware locks on the Java optimized processor. We find that the additional overhead for priority ceiling emulation on a multicore processor is several times higher than simpler, non-premptive locks, mainly...

  16. Automatic Generation of Machine Emulators: Efficient Synthesis of Robust Virtual Machines for Legacy Software Migration

    DEFF Research Database (Denmark)

    Franz, Michael; Gal, Andreas; Probst, Christian

    2006-01-01

    As older mainframe architectures become obsolete, the corresponding le- gacy software is increasingly executed via platform emulators running on top of more modern commodity hardware. These emulators are virtual machines that often include a combination of interpreters and just-in-time compilers....... Implementing interpreters and compilers for each combination of emulated and target platform independently of each other is a redundant and error-prone task. We describe an alternative approach that automatically synthesizes specialized virtual-machine interpreters and just-in-time compilers, which...... then execute on top of an existing software portability platform such as Java. The result is a considerably reduced implementation effort....

  17. Experimental verification of on-chip CMOS fractional-order capacitor emulators

    KAUST Repository

    Tsirimokou, G.

    2016-06-13

    The experimental results from a fabricated integrated circuit of fractional-order capacitor emulators are reported. The chip contains emulators of capacitors of orders 0.3, 0.4, 0.5, 0.6 and 0.7 with nano-Farad pseudo-capacitances that can be adjusted through a bias current. Two off-chip capacitors are used to set the bandwidth of each emulator independently. The chip was designed in Austria microsystems (AMS) 0.35μ CMOS. © 2016 The Institution of Engineering and Technology.

  18. Emulating human microcapillaries in a multi-organ-chip platform.

    Science.gov (United States)

    Hasenberg, Tobias; Mühleder, Severin; Dotzler, Andrea; Bauer, Sophie; Labuda, Krystyna; Holnthoner, Wolfgang; Redl, Heinz; Lauster, Roland; Marx, Uwe

    2015-12-20

    Current microfluidic chip-based tissue culture systems lack a capillary endothelial vessel system, which would enable perfusion with blood. We utilise spatial cell cultures to populate a perfused multi-organ-chip platform-a microfluidic device recently introduced for substance testing. Complete biological vascularization of such culture systems is vital to properly emulate physiological tissue behaviour. In this study, we incorporated a fibrin scaffold into the two-organ-chip design. Herein, adipose-derived stromal cells (ASCs) directed human umbilical vein endothelial cells (HUVECs) to organise into tube-like structures. The ASCs induced tube formation of HUVECs in static and dynamic conditions. The replacement of full medium enriched with growth factors and foetal calf serum with basal medium resulted in viable cells with similar gene expression profiles. We regard this as a prerequisite for studies with organ constructs that have a need for a different medium formulation. Furthermore, we here address stability issues of the fibrin gel and fibrin composition for optimal microvessel formation. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Emulation of Colonic Oxygen Gradients in a Microdevice.

    Science.gov (United States)

    Walsh, David I; Dydek, E Victoria; Lock, Jaclyn Y; Carlson, Taylor L; Carrier, Rebecca L; Kong, David S; Cabrera, Catherine R; Thorsen, Todd

    2017-11-01

    Gut-on-a-chip in vitro modeling is an emerging field, as the human gut epithelium and gut microbiome have been recently identified as novel drug targets for a wide variety of diseases. Realistic in vitro gut models require a variety of precise environmental cues, such as chemical and gas gradients, in combination with substrates like mucus that support the growth of microbial communities. This technical brief describes a microfluidic architecture capable of developing a physiologically relevant oxygen gradient that emulates the oxygen profile proximal to the epithelial inner lining of the human colon. The device generates stable and repeatable defined oxygen gradients from 0% to 4 % partial pressure O2 over a length scale of hundreds of microns, and was applied to study the effects of oxygenation on the structure of native mucus that lines the colon wall. Using simulation as a design tool for hybrid gas-liquid microfluidic devices enables on-chip creation of defined, physiologically oxygen gradients. These microfluidic architectures have powerful potential applications for gut physiology, including providing optimal oxygenation conditions for the culture of mammalian epithelial cells in the gut lining, as well as creating a realistic mimic of the oxygen gradient found in the intestinal lumen for complex microbiome cultures.

  20. Hardware-in-the-Loop emulator for a hydrokinetic turbine

    Science.gov (United States)

    Rat, C. L.; Prostean, O.; Filip, I.

    2018-01-01

    Hydroelectric power has proven to be an efficient and reliable form of renewable energy, but its impact on the environment has long been a source of concern. Hydrokinetic turbines are an emerging class of renewable energy technology designed for deployment in small rivers and streams with minimal environmental impact on the local ecosystem. Hydrokinetic technology represents a truly clean source of energy, having the potential to become a highly efficient method of harvesting renewable energy. However, in order to achieve this goal, extensive research is necessary. This paper presents a Hardware-in-the-Loop emulator for a run-of-the-river type hydrokinetic turbine. The HIL system uses an ABB ACS800 drive to control an induction machine as a significant means of replicating the behavior of the real turbine. The induction machine is coupled to a permanent magnet synchronous generator and the corresponding load. The ACS800 drive is controlled through the software system, which comprises of the hydrokinetic turbine real-time simulation through mathematical modeling in the LabVIEW programming environment running on a NI CompactRIO (cRIO) platform. The advantages of this method are that it can provide a means for testing many control configurations without requiring the presence of the real turbine. This paper contains the basic principles of a hydrokinetic turbine, particularly the run-of-the-river configurations along with the experimental results obtained from the HIL system.

  1. Insightful problem solving and emulation in brown capuchin monkeys.

    Science.gov (United States)

    Renner, Elizabeth; Abramo, Allison M; Karen Hambright, M; Phillips, Kimberley A

    2017-05-01

    We investigated problem solving abilities of capuchin monkeys via the "floating object problem," a task in which the subject must use creative problem solving to retrieve a favored food item from the bottom of a clear tube. Some great apes have solved this problem by adding water to raise the object to a level at which it can be easily grabbed. We presented seven capuchins with the task over eight trials (four "dry" and four "wet"). None of the subjects solved the task, indicating that no capuchin demonstrated insightful problem solving under these experimental conditions. We then investigated whether capuchins would emulate a solution to the task. Seven subjects observed a human model solve the problem by pouring water from a cup into the tube, which brought the object to the top of the tube, allowing the subject to retrieve it. Subjects were then allowed to interact freely with an unfilled tube containing the object in the presence of water and objects that could be used to solve the task. While most subjects were unable to solve the task after viewing a demonstrator solve it, one subject did so, but in a unique way. Our results are consistent with some previous results in great ape species and indicate that capuchins do not spontaneously solve the floating object problem via insight.

  2. Mining data from hemodynamic simulations via Bayesian emulation

    Directory of Open Access Journals (Sweden)

    Nair Prasanth B

    2007-12-01

    Full Text Available Abstract Background: Arterial geometry variability is inevitable both within and across individuals. To ensure realistic prediction of cardiovascular flows, there is a need for efficient numerical methods that can systematically account for geometric uncertainty. Methods and results: A statistical framework based on Bayesian Gaussian process modeling was proposed for mining data generated from computer simulations. The proposed approach was applied to analyze the influence of geometric parameters on hemodynamics in the human carotid artery bifurcation. A parametric model in conjunction with a design of computer experiments strategy was used for generating a set of observational data that contains the maximum wall shear stress values for a range of probable arterial geometries. The dataset was mined via a Bayesian Gaussian process emulator to estimate: (a the influence of key parameters on the output via sensitivity analysis, (b uncertainty in output as a function of uncertainty in input, and (c which settings of the input parameters result in maximum and minimum values of the output. Finally, potential diagnostic indicators were proposed that can be used to aid the assessment of stroke risk for a given patient's geometry.

  3. Six Networks on a Universal Neuromorphic Computing Substrate

    Science.gov (United States)

    Pfeil, Thomas; Grübl, Andreas; Jeltsch, Sebastian; Müller, Eric; Müller, Paul; Petrovici, Mihai A.; Schmuker, Michael; Brüderle, Daniel; Schemmel, Johannes; Meier, Karlheinz

    2013-01-01

    In this study, we present a highly configurable neuromorphic computing substrate and use it for emulating several types of neural networks. At the heart of this system lies a mixed-signal chip, with analog implementations of neurons and synapses and digital transmission of action potentials. Major advantages of this emulation device, which has been explicitly designed as a universal neural network emulator, are its inherent parallelism and high acceleration factor compared to conventional computers. Its configurability allows the realization of almost arbitrary network topologies and the use of widely varied neuronal and synaptic parameters. Fixed-pattern noise inherent to analog circuitry is reduced by calibration routines. An integrated development environment allows neuroscientists to operate the device without any prior knowledge of neuromorphic circuit design. As a showcase for the capabilities of the system, we describe the successful emulation of six different neural networks which cover a broad spectrum of both structure and functionality. PMID:23423583

  4. Statistical emulation of a tsunami model for sensitivity analysis and uncertainty quantification

    Directory of Open Access Journals (Sweden)

    A. Sarri

    2012-06-01

    Full Text Available Due to the catastrophic consequences of tsunamis, early warnings need to be issued quickly in order to mitigate the hazard. Additionally, there is a need to represent the uncertainty in the predictions of tsunami characteristics corresponding to the uncertain trigger features (e.g. either position, shape and speed of a landslide, or sea floor deformation associated with an earthquake. Unfortunately, computer models are expensive to run. This leads to significant delays in predictions and makes the uncertainty quantification impractical. Statistical emulators run almost instantaneously and may represent well the outputs of the computer model. In this paper, we use the outer product emulator to build a fast statistical surrogate of a landslide-generated tsunami computer model. This Bayesian framework enables us to build the emulator by combining prior knowledge of the computer model properties with a few carefully chosen model evaluations. The good performance of the emulator is validated using the leave-one-out method.

  5. Design and implementation of HMI and SCADA applied to a didactic emulation of a packing process

    Directory of Open Access Journals (Sweden)

    Manuel Alejandro Bohórquez-Dallos

    2013-07-01

    The supervision and control of the signals are performed with the CANopen protocol. The developed system allows the user to interact directly with the emulation of the process, triggering elements of it in the computer remotely and locally using the touch screen. The SCADA and HMI are embedded in a CoDeSys® function that the user can use as a learning tool for automating the process emulation.

  6. Just Imagine! Learning to Emulate and Infer Actions with a Stochastic Generative Architecture

    Directory of Open Access Journals (Sweden)

    Fabian eSchrodt

    2016-03-01

    Full Text Available Theories on embodied cognition emphasize that our mind develops by processing and inferring structures given the encountered bodily experiences. Here we propose a distributed neural network architecture that learns a stochastic generative model from experiencing bodily actions. Our modular system learns from various manifolds of action perceptions in the form of (i relative positional motion of the individual body parts, (ii angular motion of joints, as well as (iii relatively stable top-down action identities. By Hebbian learning, this information is spatially segmented in separate neural modules that provide embodied state codes as well as temporal predictions of the state progression inside and across the modules. The network is generative in space and time, thus, being able to predict both, missing sensory information as well as next sensory information. We link the developing encodings to visuo-motor and multimodal representations that appear to be involved in action observation. Our results show that the system learns to infer action types as well as motor codes from partial sensory information by emulating observed actions with the own developing body model. We further evaluate the generative capabilities by showing that the system is able to generate internal imaginations of the learned types of actions without sensory stimulation, including visual images of the actions. The model highlights the important roles of motor cognition and embodied simulation for bootstrapping action understanding capabilities. We conclude that stochastic generative models appear very suitable for both, generating goal-directed actions, as well as predicting observed visuo-motor trajectories and action goals.

  7. Retinal Circuit Emulator With Spatiotemporal Spike Outputs at Millisecond Resolution in Response to Visual Events.

    Science.gov (United States)

    Hayashida, Yuki; Kudo, Yuka; Ishida, Ryoya; Okuno, Hirotsugu; Yagi, Tetsuya

    2017-06-01

    To gain insights on how visual information of the real world is filtered, compressed, and encoded by the vertebrate retinas, emulating in silico the spatiotemporal patterns of the graded and action potentials of neuronal responses to natural visual scenes on biological time scale is a feasible approach. As a basic platform for such an emulation, we here developed a compact hardware system comprising an analog silicon retina and a field-programmable gate array module. With utilizing the Izhikevich formalism, a retinal circuit model that emulates spiking of ganglion cells was implemented in this system. The emulated spike timing had the resolution of about 2 ms relative to the stimulus onset and was little affected by timings of the synchronous frame sampling in the silicon retina. Thus, the emulator can mimic the event-driven spike outputs of biological retinas. The system was useful for simultaneously visualizing neural images of both the graded potentials and the spikes in response to real live visual scenes. Since our emulator system is reconfigurable, it provides a flexible platform for investigating visual functions of retinal circuits under natural visual environment.

  8. Efficient Emulation of Radiative Transfer Codes Using Gaussian Processes and Application to Land Surface Parameter Inferences

    Directory of Open Access Journals (Sweden)

    José Luis Gómez-Dans

    2016-02-01

    Full Text Available There is an increasing need to consistently combine observations from different sensors to monitor the state of the land surface. In order to achieve this, robust methods based on the inversion of radiative transfer (RT models can be used to interpret the satellite observations. This typically results in an inverse problem, but a major drawback of these methods is the computational complexity. We introduce the concept of Gaussian Process (GP emulators: surrogate functions that accurately approximate RT models using a small set of input (e.g., leaf area index, leaf chlorophyll, etc. and output (e.g., top-of-canopy reflectances or at sensor radiances pairs. The emulators quantify the uncertainty of their approximation, and provide a fast and easy route to estimating the Jacobian of the original model, enabling the use of e.g., efficient gradient descent methods. We demonstrate the emulation of widely used RT models (PROSAIL and SEMIDISCRETE and the coupling of vegetation and atmospheric (6S RT models targetting particular sensor bands. A comparison with the full original model outputs shows that the emulators are a viable option to replace the original model, with negligible bias and discrepancies which are much smaller than the typical uncertainty in the observations. We also extend the theory of GP to cope with models with multivariate outputs (e.g., over the full solar reflective domain, and apply this to the emulation of PROSAIL, coupled 6S and PROSAIL and to the emulation of individual spectral components of 6S. In all cases, emulators successfully predict the full model output as well as accurately predict the gradient of the model calculated by finite differences, and produce speed ups between 10,000 and 50,000 times that of the original model. Finally, we use emulators to invert leaf area index ( L A I , leaf chlorophyll content ( C a b and equivalent leaf water thickness ( C w from a time series of observations from Sentinel-2/MSI

  9. OpenFlow Extensions for Programmable Quantum Networks

    Science.gov (United States)

    2017-06-19

    systems connected via classical communication channels. These networks differ from standard classical networks by their use of quantum physical phenomena...apply our framework to a physical multinode quantum network after more testing is completed in our emulated environment. Approved for public...ARL-TR-8043 JUN 2017 US Army Research Laboratory OpenFlow Extensions for Programmable Quantum Networks by Venkat Dasari

  10. How to Party Like it’s 1999: Emulation for Everyone

    Directory of Open Access Journals (Sweden)

    Dianne Dietrich

    2016-04-01

    Full Text Available Emulated access of complex media has long been discussed, but there are very few instances in which complex, interactive, born-digital emulations are available to researchers. New York Public Library has made 1980-90's era video games from 5.25" floppy disks in the Timothy Leary Papers accessible via a DosBox emulator. These games appear in various stages of development and display the work of at least four of Leary's collaborators on the games. 56 disk images from the Leary Papers are currently emulated in the reading room. New York University has made late 1990s-mid 2000's era Photoshop files from the Jeremy Blake Papers accessible to researchers. The Blake Papers include over 300 pieces of media. Cornell University Library was awarded a grant from the NEH to analyze approximately 100 born-digital artworks created for CD-ROM from the Rose Goldsen Archive of New Media Art to develop preservation workflows, access strategies, and metadata frameworks. Rhizome has undertaken a number of emulation projects as a major part of its preservation strategy for born-digital artworks. In cooperation with the University of Freiburg in Germany, Rhizome recently restored several digital artworks for public access using a cloud-based emulation framework. This framework (bwFLA has been designed to facilitate the reenactments of software on a large scale, for internal use or public access. This paper will guide readers through how to implement emulation. Each of the institutions weigh in on oddities and idiosyncrasies they encountered throughout the process — from accession to access.

  11. Touch-Based Interaction Approach for Network Science Research and Visualization

    Science.gov (United States)

    2016-01-01

    wireless networks. The primary emulation tools used by ARL are the Extendable Mobile Ad hoc Network Emulator (EMANE)1 and the Common Open Research...messages containing data of interest. This data can range from network metrics collected in an experiment to server CPU statistics. VizDaemons consume only...visualization server , is required to distribute interaction notifications to multiple subscribed systems in the NSRL. Fig. 3 MultiTaction display device

  12. Statistical emulation of landslide-induced tsunamis at the Rockall Bank, NE Atlantic.

    Science.gov (United States)

    Salmanidou, D M; Guillas, S; Georgiopoulou, A; Dias, F

    2017-04-01

    Statistical methods constitute a useful approach to understand and quantify the uncertainty that governs complex tsunami mechanisms. Numerical experiments may often have a high computational cost. This forms a limiting factor for performing uncertainty and sensitivity analyses, where numerous simulations are required. Statistical emulators, as surrogates of these simulators, can provide predictions of the physical process in a much faster and computationally inexpensive way. They can form a prominent solution to explore thousands of scenarios that would be otherwise numerically expensive and difficult to achieve. In this work, we build a statistical emulator of the deterministic codes used to simulate submarine sliding and tsunami generation at the Rockall Bank, NE Atlantic Ocean, in two stages. First we calibrate, against observations of the landslide deposits, the parameters used in the landslide simulations. This calibration is performed under a Bayesian framework using Gaussian Process (GP) emulators to approximate the landslide model, and the discrepancy function between model and observations. Distributions of the calibrated input parameters are obtained as a result of the calibration. In a second step, a GP emulator is built to mimic the coupled landslide-tsunami numerical process. The emulator propagates the uncertainties in the distributions of the calibrated input parameters inferred from the first step to the outputs. As a result, a quantification of the uncertainty of the maximum free surface elevation at specified locations is obtained.

  13. Statistical evaluation of metal fill widths for emulated metal fill in parasitic extraction methodology

    Science.gov (United States)

    J-Me, Teh; Noh, Norlaili Mohd.; Aziz, Zalina Abdul

    2015-05-01

    In the chip industry today, the key goal of a chip development organization is to develop and market chips within a short time frame to gain foothold on market share. This paper proposes a design flow around the area of parasitic extraction to improve the design cycle time. The proposed design flow utilizes the usage of metal fill emulation as opposed to the current flow which performs metal fill insertion directly. By replacing metal fill structures with an emulation methodology in earlier iterations of the design flow, this is targeted to help reduce runtime in fill insertion stage. Statistical design of experiments methodology utilizing the randomized complete block design was used to select an appropriate emulated metal fill width to improve emulation accuracy. The experiment was conducted on test cases of different sizes, ranging from 1000 gates to 21000 gates. The metal width was varied from 1 x minimum metal width to 6 x minimum metal width. Two-way analysis of variance and Fisher's least significant difference test were used to analyze the interconnect net capacitance values of the different test cases. This paper presents the results of the statistical analysis for the 45 nm process technology. The recommended emulated metal fill width was found to be 4 x the minimum metal width.

  14. Copy of Using Emulation and Simulation to Understand the Large-Scale Behavior of the Internet.

    Energy Technology Data Exchange (ETDEWEB)

    Adalsteinsson, Helgi; Armstrong, Robert C.; Chiang, Ken; Gentile, Ann C.; Lloyd, Levi; Minnich, Ronald G.; Vanderveen, Keith; Van Randwyk, Jamie A; Rudish, Don W.

    2008-10-01

    We report on the work done in the late-start LDRDUsing Emulation and Simulation toUnderstand the Large-Scale Behavior of the Internet. We describe the creation of a researchplatform that emulates many thousands of machines to be used for the study of large-scale inter-net behavior. We describe a proof-of-concept simple attack we performed in this environment.We describe the successful capture of a Storm bot and, from the study of the bot and furtherliterature search, establish large-scale aspects we seek to understand via emulation of Storm onour research platform in possible follow-on work. Finally, we discuss possible future work.3

  15. Development of a Photovoltaic Array Emulator System in Real Time Considering Climatic Conditions Variations

    Directory of Open Access Journals (Sweden)

    Camilo E. Ardila-Franco

    2013-11-01

    Full Text Available This paper presents the development of an emulator that has the ability to replicate, in real time, the behavior of photovoltaic panels (PV arrays considering different conditions of irradiation and temperature for each one. The emulator consists of a data acquisition card, a programmable source and a computer. It is based on the bypass diode model that provides a better approximation to real operating conditions. The solution is computed by a simplified equation that uses the Lambert W function, which reduces the computation time. After that, it generates a solution table of values of current as a function of voltage on terminals, temperature and irradiation. Real-time emulation is performed by means of a search algorithm in the solutions table of the closest value to the voltage imposed on the terminals.

  16. Mission profile emulator for the power electronics systems of motor drive applications

    DEFF Research Database (Denmark)

    Vernica, Ionut; Blaabjerg, Frede; Ma, Ke

    2017-01-01

    Due to the adverse temperature swings which normally occur in the power semiconductor devices during the start-up and deceleration periods of the motor drive system, the thermal design and control, as well as the reliability analysis of the power devices becomes crucial. In order to facilitate...... testing and access the loading and lifetime performances, a novel stress emulator for power semiconductor devices based on the mission profile of a motor drive system is proposed and designed. The control algorithm for the stress emulator setup is introduced, and the issues concerning the Orthogonal...... Signal Generator (OSG) are addressed by means of adaptive Notch filter implementation. Finally, experimental results are provided in order to validate the effectiveness of the proposed emulation technique....

  17. Quantum Emulation of Extreme Non-Equilibrium Phenomena with Trapped Atoms

    Science.gov (United States)

    Rajagopal, Shankari V.; Fujiwara, Kurt M.; Senaratne, Ruwan; Singh, Kevin; Geiger, Zachary A.; Weld, David M.

    2017-08-01

    Ultracold atomic physics experiments offer a nearly ideal context for the investigation of quantum systems far from equilibrium. We describe three related emerging directions of research into extreme non-equilibrium phenomena in atom traps: quantum emulation of ultrafast atom-light interactions, coherent phasonic spectroscopy in tunable quasicrystals, and realization of Floquet matter in strongly-driven lattice systems. We show that all three should enable quantum emulation in parameter regimes inaccessible in solid-state experiments, facilitating a complementary approach to open problems in non-equilibrium condensed matter.

  18. Implementation in a FPGA of a configurable emulator of the LHCb Upgrade front end electronics

    CERN Document Server

    Pena Colaiocco, Diego Leonardo

    2016-01-01

    The LHCb collaboration at CERN is working towards the upgrade of the experiment, to be performed in 2019. As a part of that effort the electronics of the detector are being redesigned. There exist, already, prototypes of the back end boards. Extensive testing is required in order to check that they behave in the proper way. This work consisted in the implementation of an emulator of the front end electronics in order to test the back end prototypes. A C++ library that generates the same data as the emulator was also designed with the aim of doing, in the future, real time checking of the behaviour of the prototype.

  19. A Synthesizable VHDL Behavioral Model of A DSP On Chip Emulation Unit

    OpenAIRE

    Li, Qingsen

    2003-01-01

    This thesis describes the VHDL behavioral model design of a DSP On Chip Emulation Unit. The prototype of this design is the OnCE port of the Motorola DSP56002. Capabilities of this On Chip Emulation Unit are accessible through four pins, which allows the user to step through a program, to set the breakpoint that stop program execution at a specific address, and to examine the contents of registers, memory, and pipeline information. The detailed design that includes input/output signals and s...

  20. Computer network defense system

    Science.gov (United States)

    Urias, Vincent; Stout, William M. S.; Loverro, Caleb

    2017-08-22

    A method and apparatus for protecting virtual machines. A computer system creates a copy of a group of the virtual machines in an operating network in a deception network to form a group of cloned virtual machines in the deception network when the group of the virtual machines is accessed by an adversary. The computer system creates an emulation of components from the operating network in the deception network. The components are accessible by the group of the cloned virtual machines as if the group of the cloned virtual machines was in the operating network. The computer system moves network connections for the group of the virtual machines in the operating network used by the adversary from the group of the virtual machines in the operating network to the group of the cloned virtual machines, enabling protecting the group of the virtual machines from actions performed by the adversary.

  1. Effectiveness of a fading emulator in evaluating the performance of MIMO systems by comparison with a propagation test

    DEFF Research Database (Denmark)

    Yamamoto, Atsushi; Sakata, T.; Hayashi, T.

    2010-01-01

    This paper presents a MIMO spatial fading emulator, used to represent a street microcell environment. The fading emulator can reproduce a multipath radio propagation environment with either a uniform or non-uniform angular power spectrum (APS) in the horizontal plane. In this paper, we used...

  2. Emulating Industrial Control System Field Devices Using Gumstix Technology

    Science.gov (United States)

    2012-06-01

    get a description of an exploit or to launch an automated attack. Once the attacker has access they use a Trojan Horse or add a backdoor on the...security have resulted in numerous failures, both targeted and un-targeted. In 2003, the Sobig virus infected computers at the Amtrak dispatching...Stuxnet virus targeted specific operating characteristics to create direct physical consequences [22]. 1.1 Problem Definition Attacks on networking

  3. A state space approach to the emulator-based GPC design

    DEFF Research Database (Denmark)

    Jensen, Morten Rostgaard; Lauritsen, Morten Bach; Poulsen, Niels Kjølstad

    1996-01-01

    in models and designs based on the delta-operator. The GPC controller is interesting since it is a controller that successfully has been applied to many industrial process during the last decade. The present paper discusses an emulator-based GPC, a controller design intended for fast sampled adaptive...

  4. Integration of drinking water treatment plant process models and emulated process automation software

    NARCIS (Netherlands)

    Worm, G.I.M.

    2012-01-01

    The objective of this research is to limit the risks of fully automated operation of drinking water treatment plants and to improve their operation by using an integrated system of process models and emulated process automation software. This thesis contains the design of such an integrated system.

  5. Using Student Group Work in Higher Education to Emulate Professional Communities of Practice

    Science.gov (United States)

    Fearon, Colm; McLaughlin, Heather; Eng, Tan Yoke

    2012-01-01

    Purpose: The purpose of this paper is to discuss the value of social learning from group work that emulates a professional community of practice. Design/methodology/approach: A thought piece that first, examines the role of group-work projects as part of social learning, then outlines key arguments for social learning based upon applying a…

  6. Gradations of Emulation Learning in Infants' Imitation of Actions on Objects

    Science.gov (United States)

    Huang, Chi-Tai.; Charman, Tony

    2005-01-01

    This study explored different gradations of emulation in the imitation of actions on objects by 17-month-olds. Experiment 1 established levels of behavioral reproduction following prerecorded video demonstrations similar to those levels following live demonstrations. In Experiment 2, two digitally modified videos, where object movements or body…

  7. Emulation, imitation, over-imitation and the scope of culture for child and chimpanzee.

    Science.gov (United States)

    Whiten, Andrew; McGuigan, Nicola; Marshall-Pescini, Sarah; Hopper, Lydia M

    2009-08-27

    We describe our recent studies of imitation and cultural transmission in chimpanzees and children, which question late twentieth-century characterizations of children as imitators, but chimpanzees as emulators. As emulation entails learning only about the results of others' actions, it has been thought to curtail any capacity to sustain cultures. Recent chimpanzee diffusion experiments have by contrast documented a significant capacity for copying local behavioural traditions. Additionally, in recent 'ghost' experiments with no model visible, chimpanzees failed to replicate the object movements on which emulation is supposed to focus. We conclude that chimpanzees rely more on imitation and have greater cultural capacities than previously acknowledged. However, we also find that they selectively apply a range of social learning processes that include emulation. Recent studies demonstrating surprisingly unselective 'over-imitation' in children suggest that children's propensity to imitate has been underestimated too. We discuss the implications of these developments for the nature of social learning and culture in the two species. Finally, our new experiments directly address cumulative cultural learning. Initial results demonstrate a relative conservatism and conformity in chimpanzees' learning, contrasting with cumulative cultural learning in young children. This difference may contribute much to the contrast in these species' capacities for cultural evolution.

  8. A physics informed emulator for laser-driven radiating shock simulations

    KAUST Repository

    McClarren, Ryan G.

    2011-09-01

    This work discusses the uncertainty quantification aspect of quantification of margin and uncertainty (QMU) in the context of two linked computer codes. Specifically, we present a physics based reduction technique to deal with functional data from the first code and then develop an emulator for this reduced data. Our particular application deals with conditions created by laser deposition in a radiating shock experiment modeled using the Lagrangian, radiation-hydrodynamics code Hyades. Our goal is to construct an emulator and perform a sensitivity analysis of the functional output from Hyades to be used as an initial condition for a three-dimensional code that will compute the evolution of the radiating shock at later times. Initial attempts at purely statistical data reduction techniques, were not successful at reducing the number of parameters required to describe the Hyades output. We decided on an alternate approach using physical arguments to decide what features/locations of the output were relevant (e.g., the location of the shock front or the location of the maximum pressure) and then used a piecewise linear fit between these locations. This reduced the number of outputs needed from the emulator to 40, down from the O(1000) points in the Hyades output. Then, using Bayesian MARS and Gaussian process regression, we were able to build emulators for Hyades and study sensitivities to input parameters. © 2011 Elsevier Ltd. All rights reserved.

  9. User authentication based on the NFC host-card-emulation technology

    Science.gov (United States)

    Kološ, Jan; Kotyrba, Martin

    2017-11-01

    This paper deals with implementation of algorithms for data exchange between mobile devices supporting NFC HCE (Host-Card-Emulation) and a contactless NFC reader communicating in a read/write mode. This solution provides multiplatform architecture for data exchange between devices with a focus on safe and simple user authentication.

  10. Study on FPGA-Based Emulator for the Diagnosis of Gradual Degradation in Reciprocating Pump

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Sang Sun; Kim, Wooshik [Sejong Univ., Seoul (Korea, Republic of); Kim, Tae Yun; Chai, Jang Bom [Ajou Univ., Suwon (Korea, Republic of)

    2017-01-15

    The purpose of this study is to develop a method for diagnosing the degree of gradual degradation of a reciprocating pump caused by continuous use as a water supply pump in a nuclear power plant. Normally, the progress of such degradation is too slow to be noticed. Hence, it is difficult to determine the degree of degradation using the existing diagnostic methods. In this paper, we propose a new method by which the normal state and the degraded state of the pump can be differentiated, so that the degree of degradation can be identified. First, an emulator was developed using FPGA by providing the parameters of the pump under normal state, so that the emulator generates the information of the pump in the healthy state. Then, by comparing this information with the parameters received from various output sensors of the emulator during the current state, it is possible to identify and measure the degree of gradual degradation. This paper presents some of the results obtained during the development process, and results that show how the emulator operates, by comparing the data collected from an actual pump.

  11. Using Texas Instruments Emulators as Teaching Tools in Quantitative Chemical Analysis

    Science.gov (United States)

    Young, Vaneica Y.

    2011-01-01

    This technology report alerts upper-division undergraduate chemistry faculty and lecturers to the use of Texas Instruments emulators as virtual graphing calculators. These may be used in multimedia lectures to instruct students on the use of their graphing calculators to obtain solutions to complex chemical problems. (Contains 1 figure.)

  12. Identifying Admired Models to Increase Emulation: Development of a Multidimensional Admiration Scale

    Science.gov (United States)

    Sarapin, Susan H.; Christy, Katheryn; Lareau, Louise; Krakow, Melinda; Jensen, Jakob D.

    2015-01-01

    According to social cognitive theory, people are most likely to emulate the behaviors of admired models. Though potentially valuable to researchers and practitioners, this postulate remains untested, as there is no validated measure of admiration. To facilitate research on admiration, a 14-item measure was constructed and the resulting scores were…

  13. The Outline of Personhood Law Regarding Artificial Intelligences and Emulated Human Entities

    Science.gov (United States)

    Muzyka, Kamil

    2013-12-01

    On the verge of technological breakthroughs, which define and revolutionize our understanding of intelligence, cognition, and personhood, especially when speaking of artificial intelligences and mind uploads, one must consider the legal implications of granting personhood rights to artificial intelligences or emulated human entities

  14. Runtime Performance and Virtual Network Control Alternatives in VM-Based High-Fidelity Network Simulations

    Science.gov (United States)

    2012-12-01

    network emulation systems have been proposed, such as V-eM (Apostolopoulos and Hasapis 2006), DieCast (Gupta et al. 2008), VENICE (Liu, Raju, and...Proceedings of the 2006 3rd Symposium on Networked Systems Design and Implementation (NSDI’06), San Jose, CA, USA. Gupta, D., et al. 2008. “ DieCast

  15. Quantification of uncertainties in the tsunami hazard for Cascadia using statistical emulation

    Science.gov (United States)

    Guillas, S.; Day, S. J.; Joakim, B.

    2016-12-01

    We present new high resolution tsunami wave propagation and coastal inundation for the Cascadia region in the Pacific Northwest. The coseismic representation in this analysis is novel, and more realistic than in previous studies, as we jointly parametrize multiple aspects of the seabed deformation. Due to the large computational cost of such simulators, statistical emulation is required in order to carry out uncertainty quantification tasks, as emulators efficiently approximate simulators. The emulator replaces the tsunami model VOLNA by a fast surrogate, so we are able to efficiently propagate uncertainties from the source characteristics to wave heights, in order to probabilistically assess tsunami hazard for Cascadia. We employ a new method for the design of the computer experiments in order to reduce the number of runs while maintaining good approximations properties of the emulator. Out of the initial nine parameters, mostly describing the geometry and time variation of the seabed deformation, we drop two parameters since these turn out to not have an influence on the resulting tsunami waves at the coast. We model the impact of another parameter linearly as its influence on the wave heights is identified as linear. We combine this screening approach with the sequential design algorithm MICE (Mutual Information for Computer Experiments), that adaptively selects the input values at which to run the computer simulator, in order to maximize the expected information gain (mutual information) over the input space. As a result, the emulation is made possible and accurate. Starting from distributions of the source parameters that encapsulate geophysical knowledge of the possible source characteristics, we derive distributions of the tsunami wave heights along the coastline.

  16. Evidence for emulation in chimpanzees in social settings using the floating peanut task.

    Directory of Open Access Journals (Sweden)

    Claudio Tennie

    Full Text Available BACKGROUND: It is still unclear which observational learning mechanisms underlie the transmission of difficult problem-solving skills in chimpanzees. In particular, two different mechanisms have been proposed: imitation and emulation. Previous studies have largely failed to control for social factors when these mechanisms were targeted. METHODS: In an attempt to resolve the existing discrepancies, we adopted the 'floating peanut task', in which subjects need to spit water into a tube until it is sufficiently full for floating peanuts to be grasped. In a previous study only a few chimpanzees were able to invent the necessary solution (and they either did so in their first trials or never. Here we compared success levels in baseline tests with two experimental conditions that followed: 1 A full model condition to test whether social demonstrations would be effective, and 2 A social emulation control condition, in which a human experimenter poured water from a bottle into the tube, to test whether results information alone (present in both experimental conditions would also induce successes. Crucially, we controlled for social factors in both experimental conditions. Both types of demonstrations significantly increased successful spitting, with no differences between demonstration types. We also found that younger subjects were more likely to succeed than older ones. Our analysis showed that mere order effects could not explain our results. CONCLUSION: The full demonstration condition (which potentially offers additional information to observers, in the form of actions, induced no more successes than the emulation condition. Hence, emulation learning could explain the success in both conditions. This finding has broad implications for the interpretation of chimpanzee traditions, for which emulation learning may perhaps suffice.

  17. High fidelity wireless network evaluation for heterogeneous cognitive radio networks

    Science.gov (United States)

    Ding, Lei; Sagduyu, Yalin; Yackoski, Justin; Azimi-Sadjadi, Babak; Li, Jason; Levy, Renato; Melodia, Tammaso

    2012-06-01

    We present a high fidelity cognitive radio (CR) network emulation platform for wireless system tests, measure- ments, and validation. This versatile platform provides the configurable functionalities to control and repeat realistic physical channel effects in integrated space, air, and ground networks. We combine the advantages of scalable simulation environment with reliable hardware performance for high fidelity and repeatable evaluation of heterogeneous CR networks. This approach extends CR design only at device (software-defined-radio) or lower-level protocol (dynamic spectrum access) level to end-to-end cognitive networking, and facilitates low-cost deployment, development, and experimentation of new wireless network protocols and applications on frequency- agile programmable radios. Going beyond the channel emulator paradigm for point-to-point communications, we can support simultaneous transmissions by network-level emulation that allows realistic physical-layer inter- actions between diverse user classes, including secondary users, primary users, and adversarial jammers in CR networks. In particular, we can replay field tests in a lab environment with real radios perceiving and learning the dynamic environment thereby adapting for end-to-end goals over distributed spectrum coordination channels that replace the common control channel as a single point of failure. CR networks offer several dimensions of tunable actions including channel, power, rate, and route selection. The proposed network evaluation platform is fully programmable and can reliably evaluate the necessary cross-layer design solutions with configurable op- timization space by leveraging the hardware experiments to represent the realistic effects of physical channel, topology, mobility, and jamming on spectrum agility, situational awareness, and network resiliency. We also provide the flexibility to scale up the test environment by introducing virtual radios and establishing seamless signal

  18. Full Duplex Emulation via Spatial Separation of Half Duplex Nodes in a Planar Cellular Network

    DEFF Research Database (Denmark)

    Thomsen, Henning; Kim, Dong Min; Popovski, Petar

    2016-01-01

    (HD-BSs), which is a scheme termed CoMPflex (CoMP for In-Band Wireless Full Duplex). A FD-BS can be seen as a special case of CoMPflex with separation distance zero. In this paper we study the performance of CoMPflex in a two-dimensional cellular scenario using stochastic geometry and compare......A Full Duplex Base Station (FD-BS) can be used to serve simultaneously two Half-Duplex (HD) Mobile Stations (MSs), one working in the uplink and one in the downlink, respectively. The same functionality can be realized by having two interconnected and spatially separated Half Duplex Base Stations...

  19. LHCb: Dynamically Adaptive Header Generator and Front-End Source Emulator for a 100 Gbps FPGA Based DAQ

    CERN Multimedia

    Srikanth, S

    2014-01-01

    The proposed upgrade for the LHCb experiment envisages a system of 500 Data sources each generating data at 100 Gbps, the acquisition and processing of which is a big challenge even for the current state of the art FPGAs. This requires an FPGA DAQ module that not only handles the data generated by the experiment but also is versatile enough to dynamically adapt to potential inadequacies of other components like the network and PCs. Such a module needs to maintain real time operation while at the same time maintaining system stability and overall data integrity. This also creates a need for a Front-end source Emulator capable of generating the various data patterns, that acts as a testbed to validate the functionality and performance of the Header Generator. The rest of the abstract briefly describes these modules and their implementation. The Header Generator is used to packetize the streaming data from the detectors before it is sent to the PCs for further processing. This is achieved by continuously scannin...

  20. Performance emulation and parameter estimation for nonlinear fibre-optic links

    DEFF Research Database (Denmark)

    Piels, Molly; Porto da Silva, Edson; Zibar, Darko

    2016-01-01

    Fibre-optic communication systems, especially when operating in the nonlinear regime, generally do not perform exactly as theory would predict. A number of methods for data-based evaluation of nonlinear fibre-optic link parameters, both for accurate performance emulation and optimization, are rev......Fibre-optic communication systems, especially when operating in the nonlinear regime, generally do not perform exactly as theory would predict. A number of methods for data-based evaluation of nonlinear fibre-optic link parameters, both for accurate performance emulation and optimization......, are reviewed. In particular, single-step nonlinear impairment based on the Gaussian mixture model, adaptive digital backpropagation, and extension to higher-dimensional spaces using Monte Carlo Markov chains are discussed....

  1. Computational Complexity Reduction in Nonuniform Compressed Sensing by Multi-Coset Emulation

    DEFF Research Database (Denmark)

    Grigoryan, Ruben; Jensen, Tobias Lindstrøm; Larsen, Torben

    2017-01-01

    performance–complexity tradeoffs due to the difference of the \\{SNS\\} and \\{MCS\\} models. We investigate these tradeoffs with numerical simulations and theoretical assessments of the reconstruction complexity in multi-band signal scenarios. These scenarios include different numbers, different widths......Abstract Single-channel Nonuniform Sampling (SNS) is a Compressed Sensing (CS) approach that allows sub-Nyquist sampling of frequency sparse signals. The relatively simple architecture, comprising one wide-band sampling channel, makes it an attractive solution for applications such as signal...... analyzers and telecommunications. However, a high computational cost of the \\{SNS\\} signal reconstruction is an obstacle for real-time applications. This paper proposes to emulate Multi-Coset Sampling (MCS) in \\{SNS\\} acquisition as a means to decrease the computational costs. Such an emulation introduces...

  2. Statistical Emulation of Climate Model Projections Based on Precomputed GCM Runs*

    KAUST Repository

    Castruccio, Stefano

    2014-03-01

    The authors describe a new approach for emulating the output of a fully coupled climate model under arbitrary forcing scenarios that is based on a small set of precomputed runs from the model. Temperature and precipitation are expressed as simple functions of the past trajectory of atmospheric CO2 concentrations, and a statistical model is fit using a limited set of training runs. The approach is demonstrated to be a useful and computationally efficient alternative to pattern scaling and captures the nonlinear evolution of spatial patterns of climate anomalies inherent in transient climates. The approach does as well as pattern scaling in all circumstances and substantially better in many; it is not computationally demanding; and, once the statistical model is fit, it produces emulated climate output effectively instantaneously. It may therefore find wide application in climate impacts assessments and other policy analyses requiring rapid climate projections.

  3. A Simple Cache Emulator for Evaluating Cache Behavior for SMP Systems

    Directory of Open Access Journals (Sweden)

    I. Šimeček

    2006-01-01

    Full Text Available Every modern CPU uses a complex memory hierarchy, which consists of multiple cache memory levels. It is very difficult to predict the behavior of this hierarchy for a given program (for details see [1, 2]. The situation is even worse for systems with a shared memory. The most important example is the case of SMP (symmetric multiprocessing systems [3]. The importance of these systems is growing due to the multi-core feature of the newest CPUs.The Cache Emulator (CE can simulate the behavior of caches inside an SMP system and compute the number of cache misses during a computation. All measurements are done in the “off-line” mode on a single CPU. The CE uses its own emulated cache memory for an exact simulation. This means that no other CPU activity influences the behavior of the CE. This work extends the Cache Analyzer introduced in [4]. 

  4. Emulation and design of terahertz reflection-mode confocal scanning microscopy based on virtual pinhole

    Science.gov (United States)

    Yang, Yong-fa; Li, Qi

    2014-12-01

    In the practical application of terahertz reflection-mode confocal scanning microscopy, the size of detector pinhole is an important factor that determines the performance of spatial resolution characteristic of the microscopic system. However, the use of physical pinhole brings some inconvenience to the experiment and the adjustment error has a great influence on the experiment result. Through reasonably selecting the parameter of matrix detector virtual pinhole (VPH), it can efficiently approximate the physical pinhole. By using this approach, the difficulty of experimental calibration is reduced significantly. In this article, an imaging scheme of terahertz reflection-mode confocal scanning microscopy that is based on the matrix detector VPH is put forward. The influence of detector pinhole size on the axial resolution of confocal scanning microscopy is emulated and analyzed. Then, the parameter of VPH is emulated when the best axial imaging performance is reached.

  5. Integration of drinking water treatment plant process models and emulated process automation software

    OpenAIRE

    Worm, G.I.M.

    2012-01-01

    The objective of this research is to limit the risks of fully automated operation of drinking water treatment plants and to improve their operation by using an integrated system of process models and emulated process automation software. This thesis contains the design of such an integrated system. The use of the system is investigated in the three identified applications, i) optimization of process control, ii) training of operation supervisors and iii) virtual commissioning of process autom...

  6. The Coyote Universe Extended: Precision Emulation of the Matter Power Spectrum

    Science.gov (United States)

    Heitmann, Katrin; Lawrence, Earl; Kwan, Juliana; Habib, Salman; Higdon, David

    2014-01-01

    Modern sky surveys are returning precision measurements of cosmological statistics such as weak lensing shear correlations, the distribution of galaxies, and cluster abundance. To fully exploit these observations, theorists must provide predictions that are at least as accurate as the measurements, as well as robust estimates of systematic errors that are inherent to the modeling process. In the nonlinear regime of structure formation, this challenge can only be overcome by developing a large-scale, multi-physics simulation capability covering a range of cosmological models and astrophysical processes. As a first step to achieving this goal, we have recently developed a prediction scheme for the matter power spectrum (a so-called emulator), accurate at the 1% level out to k ~ 1 Mpc-1 and z = 1 for wCDM cosmologies based on a set of high-accuracy N-body simulations. It is highly desirable to increase the range in both redshift and wavenumber and to extend the reach in cosmological parameter space. To make progress in this direction, while minimizing computational cost, we present a strategy that maximally reuses the original simulations. We demonstrate improvement over the original spatial dynamic range by an order of magnitude, reaching k ~ 10 h Mpc-1, a four-fold increase in redshift coverage, to z = 4, and now include the Hubble parameter as a new independent variable. To further the range in k and z, a new set of nested simulations run at modest cost is added to the original set. The extension in h is performed by including perturbation theory results within a multi-scale procedure for building the emulator. This economical methodology still gives excellent error control, ~5% near the edges of the domain of applicability of the emulator. A public domain code for the new emulator is released as part of the work presented in this paper.

  7. Toward Automating Web Protocol Configuration for a Programmable Logic Controller Emulator

    Science.gov (United States)

    2014-06-19

    of a PLC using an automated configuration process. The resulting automatically-configured emulator (ACE) should respond with a goal of 100% accuracy...which could then be used to log activity in the system . Another potential use is in academic settings. In order to educate people on the PLCs 2...pieces of SCADA systems [Lev11]. This is a problem because PLCs control the major functions of an ICS. Infrastructure and manufacturing began using

  8. A physics informed emulator for laser-driven radiating shock simulations

    Energy Technology Data Exchange (ETDEWEB)

    McClarren, Ryan G., E-mail: rgm@tamu.edu [Department of Nuclear Engineering, Texas A and M University, College Station, TX 77843-3133 (United States); Ryu, D. [Department of Statistics, Texas A and M University, College Station, TX 77843-3143 (United States); Paul Drake, R.; Grosskopf, Michael [Atmospheric Oceanic and Space Sciences, Space Physics Research Laboratory, University of Michigan, Ann Arbor, MI 48109 (United States); Bingham, Derek [Department of Statistics and Actuarial Science, Simon Fraser University, Burnaby, BC (Canada); Chou, Chuan-Chih; Fryxell, Bruce; Holst, Bart van der [Atmospheric Oceanic and Space Sciences, Space Physics Research Laboratory, University of Michigan, Ann Arbor, MI 48109 (United States); Paul Holloway, James [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Kuranz, Carolyn C. [Atmospheric Oceanic and Space Sciences, Space Physics Research Laboratory, University of Michigan, Ann Arbor, MI 48109 (United States); Mallick, Bani [Department of Statistics, Texas A and M University, College Station, TX 77843-3143 (United States); Rutter, Erica [Atmospheric Oceanic and Space Sciences, Space Physics Research Laboratory, University of Michigan, Ann Arbor, MI 48109 (United States); Torralva, Ben R. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI 48109 (United States)

    2011-09-15

    This work discusses the uncertainty quantification aspect of quantification of margin and uncertainty (QMU) in the context of two linked computer codes. Specifically, we present a physics based reduction technique to deal with functional data from the first code and then develop an emulator for this reduced data. Our particular application deals with conditions created by laser deposition in a radiating shock experiment modeled using the Lagrangian, radiation-hydrodynamics code Hyades. Our goal is to construct an emulator and perform a sensitivity analysis of the functional output from Hyades to be used as an initial condition for a three-dimensional code that will compute the evolution of the radiating shock at later times. Initial attempts at purely statistical data reduction techniques, were not successful at reducing the number of parameters required to describe the Hyades output. We decided on an alternate approach using physical arguments to decide what features/locations of the output were relevant (e.g., the location of the shock front or the location of the maximum pressure) and then used a piecewise linear fit between these locations. This reduced the number of outputs needed from the emulator to 40, down from the O(1000) points in the Hyades output. Then, using Bayesian MARS and Gaussian process regression, we were able to build emulators for Hyades and study sensitivities to input parameters. - Highlights: > Uncertainty quantification for two linked computer codes is investigated. > We perform physics-based dimension reduction on the code output. > This reduces the uncertain degrees of freedom from hundreds to tens.

  9. Development of adaptive core emulator for PMS-XRBP of CE type plant

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jae Seung; Zee, Sung Quun; Lee, Chung Chan; Lee, Ki Bog; Rhy, Hyo Sang; Chang, Jong Hwa; Lee, Young Ouk; Baek, Seung Min; Seo, Ho Joon

    1996-12-01

    The purpose of this report is to develop ONED-based adaptive core emulator (ACE) for Korean Standard Nuclear Power Plant. This report is first year report and includes (1) augmentation of ONED94 I/O system (2) non-equilibrium xenon initialization for core transient simulation (3) ONED94 verification via plant measurements (4) automatic data link system from PMS and personal computer. (author). 4 tabs., 4 figs., 8 refs.

  10. Experimental realization of the Furuta pendulum to emulate the Segway motion

    OpenAIRE

    Pujol, Gisela; Acho, Leonardo; Nápoles, Amelia; Pérez-García, Vega

    2014-01-01

    A Laboratory device is designed to emulate the Segway motion, modifying the Furuta pendulum experiment. To copy the person on the Segway transportation unit to the Furuta pendulum, a second pendulum is added to the main one. Using LMI theory, the control objective consists to manipulate the base of the Furuta pendulum according to the inclination of the added pendulum whereas the coupled pendulums are maintained near to theirs upright positions. According to the inclination of the second pend...

  11. Sentient networks

    Energy Technology Data Exchange (ETDEWEB)

    Chapline, G.

    1998-03-01

    The engineering problems of constructing autonomous networks of sensors and data processors that can provide alerts for dangerous situations provide a new context for debating the question whether man-made systems can emulate the cognitive capabilities of the mammalian brain. In this paper we consider the question whether a distributed network of sensors and data processors can form ``perceptions`` based on sensory data. Because sensory data can have exponentially many explanations, the use of a central data processor to analyze the outputs from a large ensemble of sensors will in general introduce unacceptable latencies for responding to dangerous situations. A better idea is to use a distributed ``Helmholtz machine`` architecture in which the sensors are connected to a network of simple processors, and the collective state of the network as a whole provides an explanation for the sensory data. In general communication within such a network will require time division multiplexing, which opens the door to the possibility that with certain refinements to the Helmholtz machine architecture it may be possible to build sensor networks that exhibit a form of artificial consciousness.

  12. Microwave emulations and tight-binding calculations of transport in polyacetylene

    Energy Technology Data Exchange (ETDEWEB)

    Stegmann, Thomas, E-mail: stegmann@icf.unam.mx [Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, 62210 Cuernavaca (Mexico); Franco-Villafañe, John A., E-mail: jofravil@fis.unam.mx [Instituto de Física, Benemérita Universidad Autónoma de Puebla, Apartado Postal J-48, 72570 Puebla (Mexico); Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, 62210 Cuernavaca (Mexico); Ortiz, Yenni P. [Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, 62210 Cuernavaca (Mexico); Kuhl, Ulrich [Université de Nice – Sophia Antipolis, Laboratoire de la Physique de la Matière Condensée, CNRS, Parc Valrose, 06108 Nice (France); Mortessagne, Fabrice, E-mail: fabrice.mortessagne@unice.fr [Université de Nice – Sophia Antipolis, Laboratoire de la Physique de la Matière Condensée, CNRS, Parc Valrose, 06108 Nice (France); Seligman, Thomas H. [Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Avenida Universidad s/n, 62210 Cuernavaca (Mexico); Centro Internacional de Ciencias, 62210 Cuernavaca (Mexico)

    2017-01-05

    A novel approach to investigate the electron transport of cis- and trans-polyacetylene chains in the single-electron approximation is presented by using microwave emulation measurements and tight-binding calculations. In the emulation we take into account the different electronic couplings due to the double bonds leading to coupled dimer chains. The relative coupling constants are adjusted by DFT calculations. For sufficiently long chains a transport band gap is observed if the double bonds are present, whereas for identical couplings no band gap opens. The band gap can be observed also in relatively short chains, if additional edge atoms are absent, which cause strong resonance peaks within the band gap. The experimental results are in agreement with our tight-binding calculations using the nonequilibrium Green's function method. The tight-binding calculations show that it is crucial to include third nearest neighbor couplings to obtain the gap in the cis-polyacetylene. - Highlights: • Electronic transport in individual polyacetylene chains is studied. • Microwave emulation experiments and tight-binding calculations agree well. • In long chains a band-gap opens due the dimerization of the chain. • In short chains edge atoms cause strong resonance peaks in the center of the band-gap.

  13. The Coyote Universe. III. Simulation Suite and Precision Emulator for the Nonlinear Matter Power Spectrum

    Science.gov (United States)

    Lawrence, Earl; Heitmann, Katrin; White, Martin; Higdon, David; Wagner, Christian; Habib, Salman; Williams, Brian

    2010-04-01

    Many of the most exciting questions in astrophysics and cosmology, including the majority of observational probes of dark energy, rely on an understanding of the nonlinear regime of structure formation. In order to fully exploit the information available from this regime and to extract cosmological constraints, accurate theoretical predictions are needed. Currently, such predictions can only be obtained from costly, precision numerical simulations. This paper is the third in a series aimed at constructing an accurate calibration of the nonlinear mass power spectrum on Mpc scales for a wide range of currently viable cosmological models, including dark energy models with w ≠ -1. The first two papers addressed the numerical challenges and the scheme by which an interpolator was built from a carefully chosen set of cosmological models. In this paper, we introduce the "Coyote Universe" simulation suite which comprises nearly 1000 N-body simulations at different force and mass resolutions, spanning 38 w CDM cosmologies. This large simulation suite enables us to construct a prediction scheme, or emulator, for the nonlinear matter power spectrum accurate at the percent level out to k ~= 1 h Mpc-1. We describe the construction of the emulator, explain the tests performed to ensure its accuracy, and discuss how the central ideas may be extended to a wider range of cosmological models and applications. A power spectrum emulator code is released publicly as part of this paper.

  14. An orbital emulator for pursuit-evasion game theoretic sensor management

    Science.gov (United States)

    Shen, Dan; Wang, Tao; Wang, Gang; Jia, Bin; Wang, Zhonghai; Chen, Genshe; Blasch, Erik; Pham, Khanh

    2017-05-01

    This paper develops and evaluates an orbital emulator (OE) for space situational awareness (SSA). The OE can produce 3D satellite movements using capabilities generated from omni-wheeled robot and robotic arm motion methods. The 3D motion of a satellite is partitioned into the movements in the equatorial plane and the up-down motions in the vertical plane. The 3D actions are emulated by omni-wheeled robot models while the up-down motions are performed by a stepped-motor-controlled-ball along a rod (robotic arm), which is attached to the robot. For multiple satellites, a fast map-merging algorithm is integrated into the robot operating system (ROS) and simultaneous localization and mapping (SLAM) routines to locate the multiple robots in the scene. The OE is used to demonstrate a pursuit-evasion (PE) game theoretic sensor management algorithm, which models conflicts between a space-based-visible (SBV) satellite (as pursuer) and a geosynchronous (GEO) satellite (as evader). The cost function of the PE game is based on the informational entropy of the SBV-tracking-GEO scenario. GEO can maneuver using a continuous and low thruster. The hard-in-loop space emulator visually illustrates the SSA problem solution based PE game.

  15. Performance tests of a power-electronics converter for multi-megawatt wind turbines using a grid emulator

    Science.gov (United States)

    Rizqy Averous, Nurhan; Berthold, Anica; Schneider, Alexander; Schwimmbeck, Franz; Monti, Antonello; De Doncker, Rik W.

    2016-09-01

    A vast increase of wind turbines (WT) contribution in the modern electrical grids have led to the development of grid connection requirements. In contrast to the conventional test method, testing power-electronics converters for WT using a grid emulator at Center for Wind Power Drives (CWD) RWTH Aachen University offers more flexibility for conducting test scenarios. Further analysis on the performance of the device under test (DUT) is however required when testing with grid emulator since the characteristic of the grid emulator might influence the performance of the DUT. This paper focuses on the performance analysis of the DUT when tested using grid emulator. Beside the issue regarding the current harmonics, the performance during Fault Ride-Through (FRT) is discussed in detail. A power hardware in the loop setup is an attractive solution to conduct a comprehensive study on the interaction between the power-electronics converters and the electrical grids.

  16. Synesthesia, sensory-motor contingency, and semantic emulation: how swimming style-color synesthesia challenges the traditional view of synesthesia

    National Research Council Canada - National Science Library

    Mroczko-Wąsowicz, Aleksandra; Werning, Markus

    2012-01-01

    .... In the present proposal we try to link the empirically grounded theory of sensory-motor contingency and mirror system based embodied simulation/emulation to newly discovered cases of swimming style-color synesthesia...

  17. Performance Evaluation, Emulation, and Control of Cross-Flow Hydrokinetic Turbines

    Science.gov (United States)

    Cavagnaro, Robert J.

    power, and electrical power output of a complete power take-off (PTO) system are utilized to determine the rotor hydrodynamic efficiency (maximum of 17%) and total system efficiency (maximum of 9%). A lab-based dynamometry method yields individual component and total PTO efficiencies, shown to have high variability and strong influence on total system efficiency. Dynamic efficiencies of PTO components can effect the overall efficiency of a turbine system, a result from field characterization. Thus, the ability to evaluate such components and their potential effects on turbine performance prior to field deployment is desirable. Before attempting control experiments with actual turbines, hardware-in-the-loop testing on controllable motor-generator sets or electromechanical emulation machines (EEMs) are explored to better understand power take-off response. The emulator control dynamic equations are presented, methods for scaling turbine parameters are developed and evaluated, and experimental results are presented from three EEMs programmed to emulate the same cross-flow turbine. Although hardware platforms and control implementations varied, results show that each EEM is successful in emulating the turbine model at different power levels, thus demonstrating the general feasibility of the approach. However, performance of motor control under torque command, current command, or speed command differed; torque methods required accurate characterization of the motors while speed methods utilized encoder feedback and more accurately tracked turbine dynamics. In a demonstration of an EEM for evaluating a hydrokinetic turbine implementation, a controller is used to track the maximum power-point of the turbine in response to turbulence. Utilizing realistic inflow conditions and control laws, the emulator dynamic speed response is shown to agree well at low frequencies with simulation but to deviate at high frequencies. The efficacy of an electromechanical emulator as an accurate

  18. Emulation of long-term changes in global climate: application to the late Pliocene and future

    Directory of Open Access Journals (Sweden)

    N. S. Lord

    2017-11-01

    Full Text Available Multi-millennial transient simulations of climate changes have a range of important applications, such as for investigating key geologic events and transitions for which high-resolution palaeoenvironmental proxy data are available, or for projecting the long-term impacts of future climate evolution on the performance of geological repositories for the disposal of radioactive wastes. However, due to the high computational requirements of current fully coupled general circulation models (GCMs, long-term simulations can generally only be performed with less complex models and/or at lower spatial resolution. In this study, we present novel long-term continuous projections of climate evolution based on the output from GCMs, via the use of a statistical emulator. The emulator is calibrated using ensembles of GCM simulations, which have varying orbital configurations and atmospheric CO2 concentrations and enables a variety of investigations of long-term climate change to be conducted, which would not be possible with other modelling techniques on the same temporal and spatial scales. To illustrate the potential applications, we apply the emulator to the late Pliocene (by modelling surface air temperature – SAT, comparing its results with palaeo-proxy data for a number of global sites, and to the next 200 kyr (thousand years (by modelling SAT and precipitation. A range of CO2 scenarios are prescribed for each period. During the late Pliocene, we find that emulated SAT varies on an approximately precessional timescale, with evidence of increased obliquity response at times. A comparison of atmospheric CO2 concentration for this period, estimated using the proxy sea surface temperature (SST data from different sites and emulator results, finds that relatively similar CO2 concentrations are estimated based on sites at lower latitudes, whereas higher-latitude sites show larger discrepancies. In our second illustrative application, spanning the next

  19. Network testbed creation and validation

    Energy Technology Data Exchange (ETDEWEB)

    Thai, Tan Q.; Urias, Vincent; Van Leeuwen, Brian P.; Watts, Kristopher K.; Sweeney, Andrew John

    2017-03-21

    Embodiments of network testbed creation and validation processes are described herein. A "network testbed" is a replicated environment used to validate a target network or an aspect of its design. Embodiments describe a network testbed that comprises virtual testbed nodes executed via a plurality of physical infrastructure nodes. The virtual testbed nodes utilize these hardware resources as a network "fabric," thereby enabling rapid configuration and reconfiguration of the virtual testbed nodes without requiring reconfiguration of the physical infrastructure nodes. Thus, in contrast to prior art solutions which require a tester manually build an emulated environment of physically connected network devices, embodiments receive or derive a target network description and build out a replica of this description using virtual testbed nodes executed via the physical infrastructure nodes. This process allows for the creation of very large (e.g., tens of thousands of network elements) and/or very topologically complex test networks.

  20. Network testbed creation and validation

    Science.gov (United States)

    Thai, Tan Q.; Urias, Vincent; Van Leeuwen, Brian P.; Watts, Kristopher K.; Sweeney, Andrew John

    2017-04-18

    Embodiments of network testbed creation and validation processes are described herein. A "network testbed" is a replicated environment used to validate a target network or an aspect of its design. Embodiments describe a network testbed that comprises virtual testbed nodes executed via a plurality of physical infrastructure nodes. The virtual testbed nodes utilize these hardware resources as a network "fabric," thereby enabling rapid configuration and reconfiguration of the virtual testbed nodes without requiring reconfiguration of the physical infrastructure nodes. Thus, in contrast to prior art solutions which require a tester manually build an emulated environment of physically connected network devices, embodiments receive or derive a target network description and build out a replica of this description using virtual testbed nodes executed via the physical infrastructure nodes. This process allows for the creation of very large (e.g., tens of thousands of network elements) and/or very topologically complex test networks.

  1. ORF73 LANA homologs of RRV and MneRV2 contain an extended RGG/RG-rich nuclear and nucleolar localization signal that interacts directly with importin β1 for non-classical nuclear import.

    Science.gov (United States)

    Howard, Kellie; Cherezova, Lidia; DeMaster, Laura K; Rose, Timothy M

    2017-11-01

    The latency-associated nuclear antigens (LANA) of KSHV and macaque RFHVMn, members of the RV1 rhadinovirus lineage, are closely related with conservation of complex nuclear localization signals (NLS) containing bipartite KR-rich motifs and RG-rich domains, which interact distinctly with importins α and ß1 for nuclear import via classical and non-classical pathways, respectively. RV1 LANAs are expressed in the nucleus of latently-infected cells where they inhibit replication and establish a dominant RV1 latency. Here we show that LANA homologs of macaque RRV and MneRV2 from the more distantly-related RV2 lineage, lack the KR-rich NLS, and instead have a large RG-rich NLS with multiple RG dipeptides and a conserved RGG motif. The RG-NLS interacts uniquely with importin β1, which mediates nuclear import and accumulation of RV2 LANA in the nucleolus. The alternative nuclear import and localization of RV2 LANA homologs may contribute to the dominant RV2 lytic replication phenotype. Copyright © 2017. Published by Elsevier Inc.

  2. CMOS-based Stochastically Spiking Neural Network for Optimization under Uncertainties

    Science.gov (United States)

    2017-03-01

    uncertainties. We discuss a ‘scenario generation’ circuit to non- parametrically estimate/emulate statistics of uncertain cost/constraints...are explored: (1) We discuss a ‘scenario generation’ circuit to non- parametrically estimate and emulate statistics of uncertain cost/constraints...uncertainties. The discussed mixed-signal, CMOS-based architecture of stochastically spiking neural network minimizes area/power of each cell and

  3. Uncertainty-based simulation-optimization using Gaussian process emulation: Application to coastal groundwater management

    Science.gov (United States)

    Rajabi, Mohammad Mahdi; Ketabchi, Hamed

    2017-12-01

    Combined simulation-optimization (S/O) schemes have long been recognized as a valuable tool in coastal groundwater management (CGM). However, previous applications have mostly relied on deterministic seawater intrusion (SWI) simulations. This is a questionable simplification, knowing that SWI models are inevitably prone to epistemic and aleatory uncertainty, and hence a management strategy obtained through S/O without consideration of uncertainty may result in significantly different real-world outcomes than expected. However, two key issues have hindered the use of uncertainty-based S/O schemes in CGM, which are addressed in this paper. The first issue is how to solve the computational challenges resulting from the need to perform massive numbers of simulations. The second issue is how the management problem is formulated in presence of uncertainty. We propose the use of Gaussian process (GP) emulation as a valuable tool in solving the computational challenges of uncertainty-based S/O in CGM. We apply GP emulation to the case study of Kish Island (located in the Persian Gulf) using an uncertainty-based S/O algorithm which relies on continuous ant colony optimization and Monte Carlo simulation. In doing so, we show that GP emulation can provide an acceptable level of accuracy, with no bias and low statistical dispersion, while tremendously reducing the computational time. Moreover, five new formulations for uncertainty-based S/O are presented based on concepts such as energy distances, prediction intervals and probabilities of SWI occurrence. We analyze the proposed formulations with respect to their resulting optimized solutions, the sensitivity of the solutions to the intended reliability levels, and the variations resulting from repeated optimization runs.

  4. Emulation Based Performance Investigation of FTP File Downloads over UMTS Dedicated Channels

    DEFF Research Database (Denmark)

    Teyeb, Oumer; Boussif, Malek; Sørensen, Troels Bundgaard

    2005-01-01

    The Radio Link Control (RLC) protocol of Universal Mobile Telecommunication System (UMTS) provides a link layer reliability that could mitigate the effects of the hostile radio propagation channel on packet data transmission. The RLC standard provides several mechanisms and associated parameters...... that determine the workings of this reliability scheme. In this paper, the impact of some of these schemes and parameters on the performance of FTP file downloads is investigated. The investigations are carried out using a real time emulation platform, which makes the results from this study more realistic than...

  5. Towards Emulation-as-a-Service: Cloud Services for Versatile Digital Object Access

    Directory of Open Access Journals (Sweden)

    Dirk von Suchodoletz

    2013-06-01

    Full Text Available The changing world of IT services opens the chance to more tightly integrate digital long-term preservation into systems, both for commercial and end users. The emergence of cloud offerings re-centralizes services, and end users interact with them remotely through standardized (web-client applications on their various devices. This offers the chance to use partially the same concepts and methods to access obsolete computer environments and allows for more sustainable business processes. In order to provide a large variety of user-friendly remote emulation services, especially in combination with authentic performance and user experience, a distributed system model and architecture is required, suitable to run as a cloud service, allowing for the specialization both of memory institutions and third party service providers.The shift of the usually non-trivial task of the emulation of obsolete software environments from the end user to specialized providers can help to simplify digital preservation and access strategies. Besides offering their users better access to their holdings, libraries and archives may gain new business opportunities to offer services to a third party, such as businesses requiring authentic reproduction of digital objects and processes for legal reasons. This paper discusses cloud concepts as the next logical step for accessing original digital material. Emulation-as-a-Service (EaaS fills the gap between the successful demonstration of emulation strategies as a long term access strategy and it’s perceived availability and usability. EaaS can build upon the ground of research and prototypical implementations of previous projects, and reuse well established remote access technology.In this article we develop requirements and a system model, suitable for a distributed environment. We will discuss the building blocks of the core services as well as requirements regarding access management. Finally, we will try to present a

  6. Emulating Spherical Wave Channel Models in Multi-probe Anechoic Chamber Setups

    DEFF Research Database (Denmark)

    Fan, Wei; Carreño, Xavier; Nielsen, Jesper Ødum

    2015-01-01

    Spherical wave channel modeling has attracted huge research attention for massive multiple-input multiple-output (MIMO) and short-distance MIMO systems. Current research work in multi-probe anechoic chamber systems is limited to reproduce radio channels assuming planar wavefronts. There is a need...... to emulate spherical wave channel models in multi-probe anechoic chamber setups. In this paper, a technique based on the field synthesis principle is proposed to approximate spherical waves emitted from arbitrarily located point sources with arbitrary polarizations. Simulation results show that static...

  7. A Memristor-Based Hyperchaotic System with Hidden Attractors: Dynamics, Synchronization and Circuital Emulating

    Directory of Open Access Journals (Sweden)

    V.-T. Pham

    2014-11-01

    Full Text Available Memristor-based systems and their potential applications, in which memristor is both a nonlinear element and a memory element, have been received significant attention recently. A memristor-based hyperchaotic system with hidden attractor is studied in this paper. The dynamics properties of this hyperchaotic system are discovered through equilibria, Lyapunov exponents, bifurcation diagram, Poincaré map and limit cycles. In addition, its anti-synchronization scheme via adaptive control method is also designed and MATLAB simulations are shown. Finally, an electronic circuit emulating the memristor-based hyperchaotic system has been designed using off-the-shelf components.

  8. Flexible Rechargeable Zinc-Air Batteries through Morphological Emulation of Human Hair Array.

    Science.gov (United States)

    Fu, Jing; Hassan, Fathy Mohamed; Li, Jingde; Lee, Dong Un; Ghannoum, Abdul Rahman; Lui, Gregory; Hoque, Md Ariful; Chen, Zhongwei

    2016-08-01

    An electrically rechargeable, nanoarchitectured air electrode that morphologically emulates a human hair array is demonstrated in a zinc-air battery. The hair-like array of mesoporous cobalt oxide nanopetals in nitrogen-doped carbon nanotubes is grown directly on a stainless-steel mesh. This electrode produces both flexibility and improved battery performance, and thus fully manifests the advantages of flexible rechargeable zinc-air batteries in practical applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. FPGAs Emulate Microprocessors-A Successful Case for HFC NPP Digital I and C Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Allen; Crow, Ivan; Reese, Carl; Kim, Jong; Yang, Steve [Doosan HF Controls Corp, Carrollton (United States)

    2014-08-15

    Field Programmable Gate Arrays (FPGAs), as programmable logic devices (PLDs) have gained a great deal of interests for implementing safety I and C applications in nuclear power plants (NPPs) largely owing to the FPGAs'potential advantage over the currently more common microprocessor-based digital I and C applications. First of all, FPGAs have adequate capabilities for most digital I and C applications in NPPs. Secondly, FPGAs provide products with longer lifetime, improve testability, and reduce the drift which occurs in analog-based systems, from hardware perspective. Thirdly, FPGAs, from software perspective, can be made simpler, less reliant on complex software such as operating systems, which should make FPGAs easier to qualify for nuclear safety applications. Fourthly, FPGAs are less vulnerable to cyber attacks when FPGAs implement the I and C systems that do not contain high-level, general purpose software that may be easily subjected to malicious modifications. Finally, FPGAs can bring cost reduction in an I and C digital upgrade because FPGAs can provide simpler licensing process than microprocessor-based digital I and C, and FPGAs can be implemented more efficiently. This paper will present one successful case for YGN Unit I and C upgrade using FPGA-based components to replace the obsolete Intel 8085 Microprocessor-based controllers. In this case, FPGAs emulated the process of the existing microprocessors and interpreted the execution of CPU processing. More than 160 of the FPGA-based SBC-01 controllers replacing the Intel 8085 Microprocessor-based Printed Circuit Boards have been installed and running successfully for safety I and C applications over the last five years. In this upgrade, the new FPGA-based controller board SBC-01 emulated the functions of Intel 8085 microprocessor correctly. It is a successful and cost-effective upgrade.vIn this paper, lifecycle design and implementation process and rigorous V and V activities that were used in the

  10. MEMBRAIN NEURAL NETWORK FOR VISUAL PATTERN RECOGNITION

    Directory of Open Access Journals (Sweden)

    Artur Popko

    2013-06-01

    Full Text Available Recognition of visual patterns is one of significant applications of Artificial Neural Networks, which partially emulate human thinking in the domain of artificial intelligence. In the paper, a simplified neural approach to recognition of visual patterns is portrayed and discussed. This paper is dedicated for investigators in visual patterns recognition, Artificial Neural Networking and related disciplines. The document describes also MemBrain application environment as a powerful and easy to use neural networks’ editor and simulator supporting ANN.

  11. rpe v5: an emulator for reduced floating-point precision in large numerical simulations

    Science.gov (United States)

    Dawson, Andrew; Düben, Peter D.

    2017-06-01

    This paper describes the rpe (reduced-precision emulator) library which has the capability to emulate the use of arbitrary reduced floating-point precision within large numerical models written in Fortran. The rpe software allows model developers to test how reduced floating-point precision affects the result of their simulations without having to make extensive code changes or port the model onto specialized hardware. The software can be used to identify parts of a program that are problematic for numerical precision and to guide changes to the program to allow a stronger reduction in precision.The development of rpe was motivated by the strong demand for more computing power. If numerical precision can be reduced for an application under consideration while still achieving results of acceptable quality, computational cost can be reduced, since a reduction in numerical precision may allow an increase in performance or a reduction in power consumption. For simulations with weather and climate models, savings due to a reduction in precision could be reinvested to allow model simulations at higher spatial resolution or complexity, or to increase the number of ensemble members to improve predictions. rpe was developed with a particular focus on the community of weather and climate modelling, but the software could be used with numerical simulations from other domains.

  12. rpe v5: an emulator for reduced floating-point precision in large numerical simulations

    Directory of Open Access Journals (Sweden)

    A. Dawson

    2017-06-01

    Full Text Available This paper describes the rpe (reduced-precision emulator library which has the capability to emulate the use of arbitrary reduced floating-point precision within large numerical models written in Fortran. The rpe software allows model developers to test how reduced floating-point precision affects the result of their simulations without having to make extensive code changes or port the model onto specialized hardware. The software can be used to identify parts of a program that are problematic for numerical precision and to guide changes to the program to allow a stronger reduction in precision.The development of rpe was motivated by the strong demand for more computing power. If numerical precision can be reduced for an application under consideration while still achieving results of acceptable quality, computational cost can be reduced, since a reduction in numerical precision may allow an increase in performance or a reduction in power consumption. For simulations with weather and climate models, savings due to a reduction in precision could be reinvested to allow model simulations at higher spatial resolution or complexity, or to increase the number of ensemble members to improve predictions. rpe was developed with a particular focus on the community of weather and climate modelling, but the software could be used with numerical simulations from other domains.

  13. Dependency Analysis of Legacy Digital Materials to Support Emulation Based Preservation

    Directory of Open Access Journals (Sweden)

    Aaron Hsu

    2011-03-01

    Full Text Available Emulation has been widely discussed as a preservation strategy for digital documents that depend upon proprietary executables, as well as for legacy programs. The fundamental assumption of this strategy is that an artifact (document or program will be bundled with any required contemporaneous software in an archival information package (AIP which can be loaded and executed in an emulation environment by patrons wishing to access the preserved artifact, yet little has been written about how to identify the required components for such an AIP. Even where a digital document was distributed with a binary viewer, there may be dependencies on other software libraries. In this paper we discuss a pilot study that performed dependency analysis for digital materials originally distributed on CD-ROM. In particular, we show how to utilize a small number of existing off-the-shelf libraries to build a tool that can analyze executables within ISO (CD-ROM images, and then examine the results of applying this tool to a body of archived images.

  14. Energy efficiency and color quality limits in artificial light sources emulating natural illumination.

    Science.gov (United States)

    Hertog, Wim; Llenas, Aleix; Quintero, Jesús M; Hunt, Charles E; Carreras, Josep

    2014-12-15

    We present in this work a calculation of the theoretical limits attainable for natural light emulation with regard to the joint optimization of the Luminous Efficacy of Radiation and color fidelity by using multiple reflectance spectra datasets, along with an implementation of a physical device that approaches these limits. A reduced visible spectrum of blackbody radiators is introduced and demonstrated which allows lamps designed to emulate natural light to operate with excellent color fidelity and higher efficiency as compared to full visible spectrum sources. It is shown that even though 3,000K and 5,500K blackbody sources have maximum efficacies of 21 lm/W and 89 lm/W, respectively, reduced-spectrum artificial light sources can exceed those values up to 363 lm/W and 313 lm/W, respectively, while retaining excellent color fidelity. Experimental demonstration approaching these values is accomplished through the design and implementation of a 12-channel light engine which emits arbitrarily-tunable spectra. The color fidelity of the designed spectra is assessed through Color Rendering Maps, showing that color fidelity is preserved uniformly over a large spectral reflectance dataset, unlike other approaches to generate white light.

  15. Characterization of a Prototype Radio Frequency Space Environment Path Emulator for Evaluating Spacecraft Ranging Hardware

    Science.gov (United States)

    Mitchell, Jason W.; Baldwin, Philip J.; Kurichh, Rishi; Naasz, Bo J.; Luquette, Richard J.

    2007-01-01

    The Formation Flying Testbed (FFTB) at the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) provides a hardware-in-the-loop test environment for formation navigation and control. The facility is evolving as a modular, hybrid, dynamic simulation facility for end-to-end guidance, navigation and control (GN&C) design and analysis of formation flying spacecraft. The core capabilities of the FFTB, as a platform for testing critical hardware and software algorithms in-the-loop, have expanded to include S-band Radio Frequency (RF) modems for interspacecraft communication and ranging. To enable realistic simulations that require RF ranging sensors for relative navigation, a mechanism is needed to buffer the RF signals exchanged between spacecraft that accurately emulates the dynamic environment through which the RF signals travel, including the effects of the medium, moving platforms, and radiated power. The Path Emulator for Radio Frequency Signals (PERFS), currently under development at NASA GSFC, provides this capability. The function and performance of a prototype device are presented.

  16. Development of a Radio Frequency Space Environment Path Emulator for Evaluating Spacecraft Ranging Hardware

    Science.gov (United States)

    Mitchell, Jason W.; Baldwin, Philip J.; Kurichh, Rishi; Naasz, Bo J.; Luquette, Richard J.

    2007-01-01

    The Formation Flying Testbed (FFTB) at the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) provides a hardware-in-the-loop test environment for formation navigation and control. The facility is evolving as a modular, hybrid, dynamic simulation facility for end-to-end guidance, navigation and. control (GN&C) design and analysis of formation flying spacecraft. The core capabilities of the FFTB, as a platform for testing critical hardware and software algorithms in-the-loop, have expanded to include S-band Radio Frequency (RF) modems for inter-spacecraft communication and ranging. To enable realistic simulations that require RF ranging sensors for relative navigation, a mechanism is needed to buffer the RF signals exchanged between spacecraft that accurately emulates the dynamic environment through which the RF signals travel, including the effects of medium, moving platforms, and radiated power. The Path Emulator for RF Signals (PERFS), currently under development at NASA GSFC, provides this capability. The function and performance of a prototype device are presented.

  17. Brain-Inspired Photonic Signal Processor for Generating Periodic Patterns and Emulating Chaotic Systems

    Science.gov (United States)

    Antonik, Piotr; Haelterman, Marc; Massar, Serge

    2017-05-01

    Reservoir computing is a bioinspired computing paradigm for processing time-dependent signals. Its hardware implementations have received much attention because of their simplicity and remarkable performance on a series of benchmark tasks. In previous experiments, the output was uncoupled from the system and, in most cases, simply computed off-line on a postprocessing computer. However, numerical investigations have shown that feeding the output back into the reservoir opens the possibility of long-horizon time-series forecasting. Here, we present a photonic reservoir computer with output feedback, and we demonstrate its capacity to generate periodic time series and to emulate chaotic systems. We study in detail the effect of experimental noise on system performance. In the case of chaotic systems, we introduce several metrics, based on standard signal-processing techniques, to evaluate the quality of the emulation. Our work significantly enlarges the range of tasks that can be solved by hardware reservoir computers and, therefore, the range of applications they could potentially tackle. It also raises interesting questions in nonlinear dynamics and chaos theory.

  18. The introspective may achieve more: Enhancing existing Geoscientific models with native-language emulated structural reflection

    Science.gov (United States)

    Ji, Xinye; Shen, Chaopeng

    2018-01-01

    Geoscientific models manage myriad and increasingly complex data structures as trans-disciplinary models are integrated. They often incur significant redundancy with cross-cutting tasks. Reflection, the ability of a program to inspect and modify its structure and behavior at runtime, is known as a powerful tool to improve code reusability, abstraction, and separation of concerns. Reflection is rarely adopted in high-performance Geoscientific models, especially with Fortran, where it was previously deemed implausible. Practical constraints of language and legacy often limit us to feather-weight, native-language solutions. We demonstrate the usefulness of a structural-reflection-emulating, dynamically-linked metaObjects, gd. We show real-world examples including data structure self-assembly, effortless input/output (IO) and upgrade to parallel I/O, recursive actions and batch operations. We share gd and a derived module that reproduces MATLAB-like structure in Fortran and C++. We suggest that both a gd representation and a Fortran-native representation are maintained to access the data, each for separate purposes. Embracing emulated reflection allows generically-written codes that are highly re-usable across projects.

  19. Manufacture and characterization of breast tissue phantoms for emulating benign lesions

    Science.gov (United States)

    Villamarín, J. A.; Rojas, M. A.; Potosi, O. M.; Narváez-Semanate, J. L.; Gaviria, C.

    2017-11-01

    Phantoms elaboration has turned a very important field of study during the last decades due to its applications in medicine. These objects are capable of emulating or mimicking acoustically biological tissues in which parameters like speed of sound (SOS) and attenuation are successfully attained. However, these materials are expensive depending on their characteristics (USD 460.00 - 6000.00) and is difficult to have precise measurements because of their composition. This paper presents the elaboration and characterization of low cost ( USD $25.00) breast phantoms which emulate histological normality and pathological conditions in order to support algorithm calibration procedures in imaging diagnosis. Quantitative ultrasound (QUS) was applied to estimate SOS and attenuation values for breast tissue (background) and benign lesions (fibroadenoma and cysts). Results showed values of the SOS and attenuation for the background between 1410 - 1450 m/s and 0.40 - 0.55 dB/cm at 1 MHz sampling frequency, respectively. On the other hand, the SOS obtained for the lesions ranges from 1350 to 1700 m/s and attenuation values between 0.50 - 1.80 dB/cm at 1 MHz. Finally, the fabricated phantoms allowed for obtaining ultrasonograms comparable with real ones whose acoustic parameters are in agree with those reported in the literature.

  20. Neurokernel: An Open Source Platform for Emulating the Fruit Fly Brain.

    Directory of Open Access Journals (Sweden)

    Lev E Givon

    Full Text Available We have developed an open software platform called Neurokernel for collaborative development of comprehensive models of the brain of the fruit fly Drosophila melanogaster and their execution and testing on multiple Graphics Processing Units (GPUs. Neurokernel provides a programming model that capitalizes upon the structural organization of the fly brain into a fixed number of functional modules to distinguish between these modules' local information processing capabilities and the connectivity patterns that link them. By defining mandatory communication interfaces that specify how data is transmitted between models of each of these modules regardless of their internal design, Neurokernel explicitly enables multiple researchers to collaboratively model the fruit fly's entire brain by integration of their independently developed models of its constituent processing units. We demonstrate the power of Neurokernel's model integration by combining independently developed models of the retina and lamina neuropils in the fly's visual system and by demonstrating their neuroinformation processing capability. We also illustrate Neurokernel's ability to take advantage of direct GPU-to-GPU data transfers with benchmarks that demonstrate scaling of Neurokernel's communication performance both over the number of interface ports exposed by an emulation's constituent modules and the total number of modules comprised by an emulation.

  1. On-line use of the 168/E emulator at the CERN ISR SFM detector

    CERN Document Server

    Bertuzzi, C; Frehse, H; Gavillet, P; Gokieli, R; Innocenti, Pier Giorgio; Messerli, R; Mornacchi, G; Norton, A; Porte, J P

    1981-01-01

    The Split Field Magnet Detector at the CERN ISR has been used to study events with a high transverse momentum charged particle. As a first- level computer-based trigger, a linear estimate of the track momentum by fixed point arithmetic was calculated on-line using a minicomputer. Appreciable further rejection was obtained by off-line filtering on an IBM-370/168, using pattern recognition and a fit of the triggering particle in the magnetic field. The availability of the 168/E emulator makes it possible to transfer the proven methods, used off-line, to real time data reduction. Preliminary results of filter efficiency and speed for an experiment triggering on a high P/sub T/ hadron at 10 to 20 degrees with respect to the outgoing beam are given. Possible improvements and extensions are discussed. (9 refs).

  2. Modular microfluidic system for emulation of human phase I/phase II metabolism.

    Science.gov (United States)

    Kampe, Thomas; König, Anna; Schroeder, Hendrik; Hengstler, Jan G; Niemeyer, Christof M

    2014-03-18

    We present a microfluidic device for coupled phase I/phase II metabolic reactions in vitro. The chip consists of microchannels, which are used as packed bed reactor compartments, filled with superparamagnetic microparticles bearing recombinant microsomal phase I cytochrome P450 or phase II conjugating enzymes (UDP-glucuronosyltransferase). Online coupling of the microfluidic device with LC/MS enabled the quantitative assessment of coupled phase I/phase II transformations, as demonstrated for two different substrates, 7-benzyloxy-4-trifluoromethylcoumarin (BFC) and dextromethorphan (DEX). In contrast, conventional sequential one-pot incubations did not generate measurable amounts of phase II metabolites. Because the microfluidic device is readily assembled from standard parts and can be equipped with a variety of recombinant enzymes, it provides a modular platform to emulate and investigate hepatic metabolism processes, with particular potential for targeted small-scale synthesis and identification of metabolites formed by sequential action of specific enzymes.

  3. Critical Clearing Time and Wind Power in Small Isolated Power Systems Considering Inertia Emulation

    Directory of Open Access Journals (Sweden)

    Elías Jesús Medina-Domínguez

    2015-11-01

    Full Text Available The stability and security of small and isolated power systems can be compromised when large amounts of wind power enter them. Wind power integration depends on such factors as power generation capacity, conventional generation technology or grid topology. Another issue that can be considered is critical clearing time (CCT. In this paper, wind power and CCT are studied in a small isolated power system. Two types of wind turbines are considered: a squirrel cage induction generator (SCIG and a full converter. Moreover, the full converter wind turbine’s inertia emulation capability is considered, and its impact on CCT is discussed. Voltage is taken into account because of its importance in power systems of this kind. The study focuses on the small, isolated Lanzarote-Fuerteventura power system, which is expected to be in operation by 2020.

  4. History matching of a complex epidemiological model of human immunodeficiency virus transmission by using variance emulation.

    Science.gov (United States)

    Andrianakis, I; Vernon, I; McCreesh, N; McKinley, T J; Oakley, J E; Nsubuga, R N; Goldstein, M; White, R G

    2017-08-01

    Complex stochastic models are commonplace in epidemiology, but their utility depends on their calibration to empirical data. History matching is a (pre)calibration method that has been applied successfully to complex deterministic models. In this work, we adapt history matching to stochastic models, by emulating the variance in the model outputs, and therefore accounting for its dependence on the model's input values. The method proposed is applied to a real complex epidemiological model of human immunodeficiency virus in Uganda with 22 inputs and 18 outputs, and is found to increase the efficiency of history matching, requiring 70% of the time and 43% fewer simulator evaluations compared with a previous variant of the method. The insight gained into the structure of the human immunodeficiency virus model, and the constraints placed on it, are then discussed.

  5. MIMO Fading Emulator Development with FPGA and Its Application to Performance Evaluation of Mobile Radio Systems

    Directory of Open Access Journals (Sweden)

    Yoshio Karasawa

    2017-01-01

    Full Text Available We present four new developments for a multiple-input multiple-output (MIMO over-the-air measurement system based on our previous studies. The first two developments relate to the channel model for multipath environment generation. One is a further simplification of the circuit configuration without performance degradation by reducing the number of delay generation units, which dominate the performance limit when implementing the circuit on a field-programmable gate array (FPGA. The other is to realize spatial correlation characteristics among the input ports on the transmission side, whereas the previously proposed channel model did not consider this correlation. The third development involves the details of implementing the MIMO fading emulator on an FPGA as a two-stage scheme. The fourth is the demonstration of application examples of the developed system.

  6. Emulation of Physician Tasks in Eye-Tracked Virtual Reality for Remote Diagnosis of Neurodegenerative Disease.

    Science.gov (United States)

    Orlosky, Jason; Itoh, Yuta; Ranchet, Maud; Kiyokawa, Kiyoshi; Morgan, John; Devos, Hannes

    2017-04-01

    For neurodegenerative conditions like Parkinson's disease, early and accurate diagnosis is still a difficult task. Evaluations can be time consuming, patients must often travel to metropolitan areas or different cities to see experts, and misdiagnosis can result in improper treatment. To date, only a handful of assistive or remote methods exist to help physicians evaluate patients with suspected neurological disease in a convenient and consistent way. In this paper, we present a low-cost VR interface designed to support evaluation and diagnosis of neurodegenerative disease and test its use in a clinical setting. Using a commercially available VR display with an infrared camera integrated into the lens, we have constructed a 3D virtual environment designed to emulate common tasks used to evaluate patients, such as fixating on a point, conducting smooth pursuit of an object, or executing saccades. These virtual tasks are designed to elicit eye movements commonly associated with neurodegenerative disease, such as abnormal saccades, square wave jerks, and ocular tremor. Next, we conducted experiments with 9 patients with a diagnosis of Parkinson's disease and 7 healthy controls to test the system's potential to emulate tasks for clinical diagnosis. We then applied eye tracking algorithms and image enhancement to the eye recordings taken during the experiment and conducted a short follow-up study with two physicians for evaluation. Results showed that our VR interface was able to elicit five common types of movements usable for evaluation, physicians were able to confirm three out of four abnormalities, and visualizations were rated as potentially useful for diagnosis.

  7. Aerodynamic consequences of wing morphing during emulated take-off and gliding in birds.

    Science.gov (United States)

    Klaassen van Oorschot, Brett; Mistick, Emily A; Tobalske, Bret W

    2016-10-01

    Birds morph their wings during a single wingbeat, across flight speeds and among flight modes. Such morphing may allow them to maximize aerodynamic performance, but this assumption remains largely untested. We tested the aerodynamic performance of swept and extended wing postures of 13 raptor species in three families (Accipitridae, Falconidae and Strigidae) using a propeller model to emulate mid-downstroke of flapping during take-off and a wind tunnel to emulate gliding. Based on previous research, we hypothesized that (1) during flapping, wing posture would not affect maximum ratios of vertical and horizontal force coefficients (C V :C H ), and that (2) extended wings would have higher maximum C V :C H when gliding. Contrary to each hypothesis, during flapping, extended wings had, on average, 31% higher maximum C V :C H ratios and 23% higher C V than swept wings across all biologically relevant attack angles (α), and, during gliding, maximum C V :C H ratios were similar for the two postures. Swept wings had 11% higher C V than extended wings in gliding flight, suggesting flow conditions around these flexed raptor wings may be different from those in previous studies of swifts (Apodidae). Phylogenetic affiliation was a poor predictor of wing performance, due in part to high intrafamilial variation. Mass was only significantly correlated with extended wing performance during gliding. We conclude that wing shape has a greater effect on force per unit wing area during flapping at low advance ratio, such as take-off, than during gliding. © 2016. Published by The Company of Biologists Ltd.

  8. Generic inertia emulation controller for multi-terminal voltage-source-converter high voltage direct current systems

    DEFF Research Database (Denmark)

    Zhu, Jiebei; Guerrero, Josep M.; Hung, William

    2014-01-01

    A generic Inertia Emulation Controller (INEC) scheme for Multi-Terminal Voltage-Source-Converter based HVDC (VSC-MTDC) systems is proposed and presented in this paper. The proposed INEC can be incorporated in any Grid-side Voltage-Source-Converter (GVSC) station, allowing the MTDC terminal to con...

  9. Emulating Simulations of Cosmic Dawn for 21 cm Power Spectrum Constraints on Cosmology, Reionization, and X-Ray Heating

    Science.gov (United States)

    Kern, Nicholas S.; Liu, Adrian; Parsons, Aaron R.; Mesinger, Andrei; Greig, Bradley

    2017-10-01

    Current and upcoming radio interferometric experiments are aiming to make a statistical characterization of the high-redshift 21 cm fluctuation signal spanning the hydrogen reionization and X-ray heating epochs of the universe. However, connecting 21 cm statistics to the underlying physical parameters is complicated by the theoretical challenge of modeling the relevant physics at computational speeds quick enough to enable exploration of the high-dimensional and weakly constrained parameter space. In this work, we use machine learning algorithms to build a fast emulator that can accurately mimic an expensive simulation of the 21 cm signal across a wide parameter space. We embed our emulator within a Markov Chain Monte Carlo framework in order to perform Bayesian parameter constraints over a large number of model parameters, including those that govern the Epoch of Reionization, the Epoch of X-ray Heating, and cosmology. As a worked example, we use our emulator to present an updated parameter constraint forecast for the Hydrogen Epoch of Reionization Array experiment, showing that its characterization of a fiducial 21 cm power spectrum will considerably narrow the allowed parameter space of reionization and heating parameters, and could help strengthen Planck's constraints on {σ }8. We provide both our generalized emulator code and its implementation specifically for 21 cm parameter constraints as publicly available software.

  10. Emulated Muscle Spindle and Spiking Afferents Validates VLSI Neuromorphic Hardware as a Testbed for Sensorimotor Function and Disease

    Directory of Open Access Journals (Sweden)

    Chuanxin M. Niu

    2014-12-01

    Full Text Available The lack of multi-scale empirical measurements (e.g. recording simultaneously from neurons, muscles, whole body, etc. complicates understanding of sensorimotor function in humans. This is particularly true for the understanding of development during childhood, which requires evaluation of measurements over many years. We have developed a synthetic platform for emulating multi-scale activity of the vertebrate sensorimotor system. Our design benefits from Very Large Scale Integrated-circuit (VLSI technology to provide considerable scalability and high-speed, as much as 365x faster than real-time. An essential component of our design is the proprioceptive sensor, or muscle spindle. Here we demonstrate an accurate and extremely fast emulation of a muscle spindle and its spiking afferents, which are computationally expensive but fundamental for reflex functions. We implemented a well-known rate-based model of the spindle (Mileusnic et al., 2006 and a simplified spiking sensory neuron model using the Izhikevich approximation to the Hodgkin-Huxley model. The resulting behavior of our afferent sensory system is qualitatively compatible with classic cat soleus recording (Matthews, 1964; 1972; Crowe and Matthews, 1964b. Our results suggest that this simplified structure of the spindle and afferent neuron is sufficient to produce physiologically-realistic behavior. The VLSI technology allows us to accelerate this behavior beyond 365x real-time. Our goal is to use this testbed for predicting years of disease progression with only a few days of emulation. This is the first hardware emulation of the spindle afferent system, and it may have application not only for emulation of human health and disease, but also for the construction of compliant neuromorphic robotic systems.

  11. Emulated muscle spindle and spiking afferents validates VLSI neuromorphic hardware as a testbed for sensorimotor function and disease.

    Science.gov (United States)

    Niu, Chuanxin M; Nandyala, Sirish K; Sanger, Terence D

    2014-01-01

    The lack of multi-scale empirical measurements (e.g., recording simultaneously from neurons, muscles, whole body, etc.) complicates understanding of sensorimotor function in humans. This is particularly true for the understanding of development during childhood, which requires evaluation of measurements over many years. We have developed a synthetic platform for emulating multi-scale activity of the vertebrate sensorimotor system. Our design benefits from Very Large Scale Integrated-circuit (VLSI) technology to provide considerable scalability and high-speed, as much as 365× faster than real-time. An essential component of our design is the proprioceptive sensor, or muscle spindle. Here we demonstrate an accurate and extremely fast emulation of a muscle spindle and its spiking afferents, which are computationally expensive but fundamental for reflex functions. We implemented a well-known rate-based model of the spindle (Mileusnic et al., 2006) and a simplified spiking sensory neuron model using the Izhikevich approximation to the Hodgkin-Huxley model. The resulting behavior of our afferent sensory system is qualitatively compatible with classic cat soleus recording (Crowe and Matthews, 1964b; Matthews, 1964, 1972). Our results suggest that this simplified structure of the spindle and afferent neuron is sufficient to produce physiologically-realistic behavior. The VLSI technology allows us to accelerate this behavior beyond 365× real-time. Our goal is to use this testbed for predicting years of disease progression with only a few days of emulation. This is the first hardware emulation of the spindle afferent system, and it may have application not only for emulation of human health and disease, but also for the construction of compliant neuromorphic robotic systems.

  12. Programmable multimode quantum networks

    Science.gov (United States)

    Armstrong, Seiji; Morizur, Jean-François; Janousek, Jiri; Hage, Boris; Treps, Nicolas; Lam, Ping Koy; Bachor, Hans-A.

    2012-08-01

    Entanglement between large numbers of quantum modes is the quintessential resource for future technologies such as the quantum internet. Conventionally, the generation of multimode entanglement in optics requires complex layouts of beamsplitters and phase shifters in order to transform the input modes into entangled modes. Here we report the highly versatile and efficient generation of various multimode entangled states with the ability to switch between different linear optics networks in real time. By defining our modes to be combinations of different spatial regions of one beam, we may use just one pair of multi-pixel detectors in order to measure multiple entangled modes. We programme virtual networks that are fully equivalent to the physical linear optics networks they are emulating. We present results for N=2 up to N=8 entangled modes here, including N=2, 3, 4 cluster states. Our approach introduces the highly sought after attributes of flexibility and scalability to multimode entanglement.

  13. Optimizing Neighbor Discovery for Ad hoc Networks based on the Bluetooth PAN Profile

    DEFF Research Database (Denmark)

    Kuijpers, Gerben; Nielsen, Thomas Toftegaard; Prasad, Ramjee

    2002-01-01

    IP layer neighbor discovery mechanisms rely highly on broadcast/multicast capabilities of the underlying link layer. The Bluetooth personal area network (PAN) profile has no native link layer broadcast/multicast capabilities and can only emulate this by repeatedly unicast link layer frames....... This paper introduces a neighbor discovery mechanism that utilizes the resources in the Bluetooth PAN profile more efficient. The performance of the new mechanism is investigated using a IPv6 network simulator and compared with emulated broadcasting. It is shown that the signaling overhead can...... be significantly reduced at the cost of a slight increase of processing complexity at the Bluetooth master device....

  14. Technology Developments Integrating a Space Network Communications Testbed

    Science.gov (United States)

    Kwong, Winston; Jennings, Esther; Clare, Loren; Leang, Dee

    2006-01-01

    As future manned and robotic space explorations missions involve more complex systems, it is essential to verify, validate, and optimize such systems through simulation and emulation in a low cost testbed environment. The goal of such a testbed is to perform detailed testing of advanced space and ground communications networks, technologies, and client applications that are essential for future space exploration missions. We describe the development of new technologies enhancing our Multi-mission Advanced Communications Hybrid Environment for Test and Evaluation (MACHETE) that enable its integration in a distributed space communications testbed. MACHETE combines orbital modeling, link analysis, and protocol and service modeling to quantify system performance based on comprehensive considerations of different aspects of space missions. It can simulate entire networks and can interface with external (testbed) systems. The key technology developments enabling the integration of MACHETE into a distributed testbed are the Monitor and Control module and the QualNet IP Network Emulator module. Specifically, the Monitor and Control module establishes a standard interface mechanism to centralize the management of each testbed component. The QualNet IP Network Emulator module allows externally generated network traffic to be passed through MACHETE to experience simulated network behaviors such as propagation delay, data loss, orbital effects and other communications characteristics, including entire network behaviors. We report a successful integration of MACHETE with a space communication testbed modeling a lunar exploration scenario. This document is the viewgraph slides of the presentation.

  15. The Home Country of the MNE

    DEFF Research Database (Denmark)

    Hobdari, Bersant; Gammeltoft, Peter; Li, Jing

    2017-01-01

    Research on multinational enterprises that originate from emerging economies has highlighted the importance of the home country for firms’ strategies of internationalization. In this paper, we outline a simple analytical framework linking institutions and resource munificence in the home country...... with each other, but share resources, coordinate actions and serve as each other’s role model. Strategies of outward investment thus reflect the competition and collaboration in their home country business eco-system....

  16. Ognjami mne sverknul vokzal... / Lev Livshits

    Index Scriptorium Estoniae

    Лившиц, Лев, 1924-2013

    2006-01-01

    Kunstimetseenidest Venemaal. Neist parun Alexander Stieglitzi elu oli seotud Narvaga. Tema asutatud A. Stieglitzi kunsttööstuskoolis Peterburis õppis 15 eesti kunstnikku. Raudtee rajamisest Eestis ja Reveli vaksalihoone ning seda ümbritsevate alade ajaloost

  17. mne kriitiku portreed / Andres Kurg

    Index Scriptorium Estoniae

    Kurg, Andres, 1975-

    2001-01-01

    Raamatust: 10 x 10 : 10 critics, 100 architects / autorid: Haig Beck, Jackie Cooper, Aaron Betsky, Roger Connah, Kristin Feireiss, Jorge Glusberg, Tom Heneghan, Mohsen Mostafavi, Terence Riley, Jaime Salazar, Neil Spiller. London : Phaidon, 2001

  18. Experimental Emulation of Air Fluorescence and Study of its Yield at Low Pressure Electrical Discharges

    Science.gov (United States)

    Maltezos, S.; Drakakis, E.; Fokitis, E.; Geranios, A.; Gika, V.; Karabourniotis, D.; Antonakakis Spyropoylos, N.

    Having high-resolution UV spectra produced from EAS fluorescence, one can determine in a more accurate way the effects of atmospheric attenuation of these signals by including Rayleigh, Mie-scattering as well as resonance absorption inside the atmosphere. For this reason, we developed an experimental setup for emulating the air-fluorescence using high-resolution spectroscopy in the UV range from 300 to 400 nm. We used low pressure electrical discharges in air , as light source, and registered the spectra with high resolution spectrometers of 0.25, 1, 2 and 3 m focal lengths. These pressure and temperature conditions, existing in the low pressure lamp used, are far from the ones existing during EAS fluorescence but such data might be useful for better understanding of the fluorescence emission, and also in allowing to adapt such spectrometers in dedicated fluorescence yield experiments in accelerators, since in the relevant literature there are not available data with such high resolution. In addition, there are very few experimental data taking into account the parameter temperature in space and thus we designed a monochromator for measurements of air-fluorescence yield as a function of pressure and temperature, using spectral lamps in which the above parameters can be controlled, which is presented in this work.

  19. Emulating proton-induced conformational changes in the vesicular monoamine transporter VMAT2 by mutagenesis.

    Science.gov (United States)

    Yaffe, Dana; Vergara-Jaque, Ariela; Forrest, Lucy R; Schuldiner, Shimon

    2016-11-22

    Neurotransporters located in synaptic vesicles are essential for communication between nerve cells in a process mediated by neurotransmitters. Vesicular monoamine transporter (VMAT), a member of the largest superfamily of transporters, mediates transport of monoamines to synaptic vesicles and storage organelles in a process that involves exchange of two H(+) per substrate. VMAT transport is inhibited by the competitive inhibitor reserpine, a second-line agent to treat hypertension, and by the noncompetitive inhibitor tetrabenazine, presently in use for symptomatic treatment of hyperkinetic disorders. During the transport cycle, VMAT is expected to occupy at least three different conformations: cytoplasm-facing, occluded, and lumen-facing. The lumen- to cytoplasm-facing transition, facilitated by protonation of at least one of the essential membrane-embedded carboxyls, generates a binding site for reserpine. Here we have identified residues in the cytoplasmic gate and show that mutations that disrupt the interactions in this gate also shift the equilibrium toward the cytoplasm-facing conformation, emulating the effect of protonation. These experiments provide significant insight into the role of proton translocation in the conformational dynamics of a mammalian H(+)-coupled antiporter, and also identify key aspects of the mode of action and binding of two potent inhibitors of VMAT2: reserpine binds the cytoplasm-facing conformation, and tetrabenazine binds the lumen-facing conformation.

  20. CHARACTERIZING THE FORMATION HISTORY OF MILKY WAY LIKE STELLAR HALOS WITH MODEL EMULATORS

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Facundo A.; O' Shea, Brian W. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Coleman-Smith, Christopher E. [Department of Physics, Duke University, Durham, NC 27708 (United States); Tumlinson, Jason [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Wolpert, Robert L. [Department of Statistical Science, Duke University, Durham, NC 27708-0251 (United States)

    2012-12-01

    We use the semi-analytic model ChemTreeN, coupled to cosmological N-body simulations, to explore how different galaxy formation histories can affect observational properties of Milky Way like galaxies' stellar halos and their satellite populations. Gaussian processes are used to generate model emulators that allow one to statistically estimate a desired set of model outputs at any location of a p-dimensional input parameter space. This enables one to explore the full input parameter space orders of magnitude faster than could be done otherwise. Using mock observational data sets generated by ChemTreeN itself, we show that it is possible to successfully recover the input parameter vectors used to generate the mock observables if the merger history of the host halo is known. However, our results indicate that for a given observational data set, the determination of 'best-fit' parameters is highly susceptible to the particular merger history of the host. Very different halo merger histories can reproduce the same observational data set, if the 'best-fit' parameters are allowed to vary from history to history. Thus, attempts to characterize the formation history of the Milky Way using these kind of techniques must be performed statistically, analyzing large samples of high-resolution N-body simulations.

  1. Gaussian process emulators for quantifying uncertainty in CO2 spreading predictions in heterogeneous media

    Science.gov (United States)

    Tian, Liang; Wilkinson, Richard; Yang, Zhibing; Power, Henry; Fagerlund, Fritjof; Niemi, Auli

    2017-08-01

    We explore the use of Gaussian process emulators (GPE) in the numerical simulation of CO2 injection into a deep heterogeneous aquifer. The model domain is a two-dimensional, log-normally distributed stochastic permeability field. We first estimate the cumulative distribution functions (CDFs) of the CO2 breakthrough time and the total CO2 mass using a computationally expensive Monte Carlo (MC) simulation. We then show that we can accurately reproduce these CDF estimates with a GPE, using only a small fraction of the computational cost required by traditional MC simulation. In order to build a GPE that can predict the simulator output from a permeability field consisting of 1000s of values, we use a truncated Karhunen-Loève (K-L) expansion of the permeability field, which enables the application of the Bayesian functional regression approach. We perform a cross-validation exercise to give an insight of the optimization of the experiment design for selected scenarios: we find that it is sufficient to use 100s values for the size of training set and that it is adequate to use as few as 15 K-L components. Our work demonstrates that GPE with truncated K-L expansion can be effectively applied to uncertainty analysis associated with modelling of multiphase flow and transport processes in heterogeneous media.

  2. Emulation of petroleum well-logging D-T2 correlations on a standard benchtop spectrometer.

    Science.gov (United States)

    Mitchell, J; Fordham, E J

    2011-10-01

    An experimental protocol is described that allows two-dimensional (2D) nuclear magnetic resonance (NMR) correlations of apparent diffusion coefficient D(app) and effective transverse relaxation time T(2,eff) to be acquired on a bench-top spectrometer using pulsed field gradients (PFG) in such a manner as to emulate D(app)-T(2,eff) correlations acquired using a well-logging tool with a fixed field gradient (FFG). This technique allows laboratory-scale NMR measurements of liquid-saturated cored rock to be compared directly to logging data obtained from the well by virtue of providing a comparable acquisition protocol and data format, and hence consistent data processing. This direct comparison supports the interpretation of the well-logging data, including a quantitative determination of the oil/brine saturation. The D-T(2) pulse sequence described here uses two spin echoes (2SE) with a variable echo time to encode for diffusion. The diffusion and relaxation contributions to the signal decay are then deconvolved using a 2D numerical inversion. This measurement allows shorter relaxation time components to be probed than in conventional diffusion measurements. A brief discussion of the numerical inversion algorithms available for inverting these non-rectangular data is included. The PFG-2SE sequence described is well suited to laboratory-scale studies of porous media and short T(2) samples in general. Copyright © 2011 Elsevier Inc. All rights reserved.

  3. Meta-modelling, visualization and emulation of multi-dimensional data for virtual production intelligence

    Science.gov (United States)

    Schulz, Wolfgang; Hermanns, Torsten; Al Khawli, Toufik

    2017-07-01

    Decision making for competitive production in high-wage countries is a daily challenge where rational and irrational methods are used. The design of decision making processes is an intriguing, discipline spanning science. However, there are gaps in understanding the impact of the known mathematical and procedural methods on the usage of rational choice theory. Following Benjamin Franklin's rule for decision making formulated in London 1772, he called "Prudential Algebra" with the meaning of prudential reasons, one of the major ingredients of Meta-Modelling can be identified finally leading to one algebraic value labelling the results (criteria settings) of alternative decisions (parameter settings). This work describes the advances in Meta-Modelling techniques applied to multi-dimensional and multi-criterial optimization by identifying the persistence level of the corresponding Morse-Smale Complex. Implementations for laser cutting and laser drilling are presented, including the generation of fast and frugal Meta-Models with controlled error based on mathematical model reduction Reduced Models are derived to avoid any unnecessary complexity. Both, model reduction and analysis of multi-dimensional parameter space are used to enable interactive communication between Discovery Finders and Invention Makers. Emulators and visualizations of a metamodel are introduced as components of Virtual Production Intelligence making applicable the methods of Scientific Design Thinking and getting the developer as well as the operator more skilled.

  4. Emulation of computer mouse control with a noninvasive brain computer interface

    Science.gov (United States)

    McFarland, Dennis J.; Krusienski, Dean J.; Sarnacki, William A.; Wolpaw, Jonathan R.

    2008-06-01

    Brain-computer interface (BCI) technology can provide nonmuscular communication and control to people who are severely paralyzed. BCIs can use noninvasive or invasive techniques for recording the brain signals that convey the user's commands. Although noninvasive BCIs are used for simple applications, it has frequently been assumed that only invasive BCIs, which use electrodes implanted in the brain, will be able to provide multidimensional sequential control of a robotic arm or a neuroprosthesis. The present study shows that a noninvasive BCI using scalp-recorded electroencephalographic (EEG) activity and an adaptive algorithm can provide people, including people with spinal cord injuries, with two-dimensional cursor movement and target selection. Multiple targets were presented around the periphery of a computer screen, with one designated as the correct target. The user's task was to use EEG to move a cursor from the center of the screen to the correct target and then to use an additional EEG feature to select the target. If the cursor reached an incorrect target, the user was instructed not to select it. Thus, this task emulated the key features of mouse operation. The results indicate that people with severe motor disabilities could use brain signals for sequential multidimensional movement and selection.

  5. Towards Optimization of a Novel Trileaflet Polymeric Prosthetic Heart Valve Via Device Thrombogenicity Emulation (DTE)

    Science.gov (United States)

    Claiborne, Thomas E.; Xenos, Michalis; Sheriff, Jawaad; Chiu, Wei-Che; Soares, Joao; Alemu, Yared; Gupta, Shikha; Judex, Stefan; Slepian, Marvin J.; Bluestein, Danny

    2013-01-01

    Aortic stenosis the is most prevalent and life threatening form of valvular heart disease. It is primarily treated via open-heart surgical valve replacement with either a tissue or mechanical prosthetic heart valve (PHV), each prone to degradation and thrombosis, respectively. Polymeric PHVs may be optimized to eliminate these complications, and they may be more suitable for the new transcatheter aortic valve replacement (TAVR) procedure and in devices like the Total Artificial Heart. However, the development of polymer PHVs has been hampered by persistent in vivo calcification, degradation, and thrombosis. To address these issues, we have developed a novel surgically implantable polymer PHV comprised of a new thermoset polyolefin called xSIBS, in which key parameters were optimized for superior functionality via our Device Thrombogenicity Emulation (DTE) methodology. In this parametric study, we compared our homogeneous optimized polymer PHV to a prior composite polymer PHV and to a benchmark tissue valve. Our results show significantly improved hemodynamics and reduced thrombogenicity in the optimized polymer PHV compared to the other valves. These results indicate that our new design may not require anticoagulants and may be more durable than its predecessor, and validates the improvement, towards optimization, of this novel polymeric PHV design. PMID:23644615

  6. Retrieval of Spatial Join Pattern Instances from Sensor Networks

    DEFF Research Database (Denmark)

    Yiu, Man Lung; Mamoulis, Nikos; Bakiras, Spiridon

    2009-01-01

    We study the continuous evaluation of spatial join queries and extensions thereof, defined by interesting combinations of sensor readings (events) that co-occur in a spatial neighborhood. An example of such a pattern is "a high temperature reading in the vicinity of at least four high...... for sensing, and network topology. Finally, we experimentally compare the effectiveness of the proposed solutions on an experimental platform that emulates real sensor networks....

  7. Bayesian history matching of complex infectious disease models using emulation: a tutorial and a case study on HIV in Uganda.

    Directory of Open Access Journals (Sweden)

    Ioannis Andrianakis

    2015-01-01

    Full Text Available Advances in scientific computing have allowed the development of complex models that are being routinely applied to problems in disease epidemiology, public health and decision making. The utility of these models depends in part on how well they can reproduce empirical data. However, fitting such models to real world data is greatly hindered both by large numbers of input and output parameters, and by long run times, such that many modelling studies lack a formal calibration methodology. We present a novel method that has the potential to improve the calibration of complex infectious disease models (hereafter called simulators. We present this in the form of a tutorial and a case study where we history match a dynamic, event-driven, individual-based stochastic HIV simulator, using extensive demographic, behavioural and epidemiological data available from Uganda. The tutorial describes history matching and emulation. History matching is an iterative procedure that reduces the simulator's input space by identifying and discarding areas that are unlikely to provide a good match to the empirical data. History matching relies on the computational efficiency of a Bayesian representation of the simulator, known as an emulator. Emulators mimic the simulator's behaviour, but are often several orders of magnitude faster to evaluate. In the case study, we use a 22 input simulator, fitting its 18 outputs simultaneously. After 9 iterations of history matching, a non-implausible region of the simulator input space was identified that was 10(11 times smaller than the original input space. Simulator evaluations made within this region were found to have a 65% probability of fitting all 18 outputs. History matching and emulation are useful additions to the toolbox of infectious disease modellers. Further research is required to explicitly address the stochastic nature of the simulator as well as to account for correlations between outputs.

  8. Extending the Coyote emulator to dark energy models with standard w0-wa parametrization of the equation of state

    Science.gov (United States)

    Casarini, L.; Bonometto, S. A.; Tessarotto, E.; Corasaniti, P.-S.

    2016-08-01

    We discuss an extension of the Coyote emulator to predict non-linear matter power spectra of dark energy (DE) models with a scale factor dependent equation of state of the form w = w0+(1-a)wa. The extension is based on the mapping rule between non-linear spectra of DE models with constant equation of state and those with time varying one originally introduced in ref. [40]. Using a series of N-body simulations we show that the spectral equivalence is accurate to sub-percent level across the same range of modes and redshift covered by the Coyote suite. Thus, the extended emulator provides a very efficient and accurate tool to predict non-linear power spectra for DE models with w0-wa parametrization. According to the same criteria we have developed a numerical code that we have implemented in a dedicated module for the CAMB code, that can be used in combination with the Coyote Emulator in likelihood analyses of non-linear matter power spectrum measurements. All codes can be found at https://github.com/luciano-casarini/pkequal.

  9. Modeling and Experimental Test of Grid-Tied Photovoltaic Cell Emulating System in the Stand-alone Mode

    Directory of Open Access Journals (Sweden)

    Vu Minh Phap

    2017-06-01

    Full Text Available In recent decades, generation of electricity from solar arrays has been increased to meet the world's growing energy demand. However, the utilization rate of the power conditioner in the grid-tied solar power system is low because the operation of solar panels is dependent on sunlight. Thus, we studied the method that the small scale wind power generating system in size from a few hundred watts to two or three kilowatts can be connected to the grid-tied power conditioner of the solar power system for residential applications with low power ratings (single phase, size is limited to 10kW by emulating characteristic of the solar panel. In this paper, we introduce the application of the grid-tied PV cell emulating system in the stand-alone mode to improve the utilization rate of the power conditioner. The simulation and experimental test results verify that the PV cell emulating system can operate the power conditioner of the gridtied solar power system.

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

    Directory of Open Access Journals (Sweden)

    Dongkyun Kim

    2017-12-01

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

  11. Online intravenous pump emulator: As effective as face-to-face simulation for training nursing students.

    Science.gov (United States)

    Terry, Victoria R; Moloney, Clint; Bowtell, Leslie; Terry, Peter C

    2016-05-01

    The expansion of online education for nursing students has created the challenge of finding innovative ways to teach clinical skills. An online intravenous pump emulator (IVPE) modelled on actual IV pumps used in clinical healthcare settings was developed to facilitate online education delivery. The objectives of the study were to implement the online IVPE and evaluate student learning outcomes and perceptions of device use. A mixed method, quasi-experimental design was used. The study was conducted in the School of Nursing and Midwifery at a regional university in Queensland, Australia. Participants were 179 first year nursing students enrolled in a medications course, ranging in age from 18 to 44years, of whom 150 were female. Participants were assigned to one of three groups and trained in the use of IV infusion pumps. Group 1 (n=57) were trained online using the IVPE (ONL); Group 2 (n=73) were trained on-campus using an actual IV pump (ONC); Group 3 (n=49) were trained both on-campus using the actual IV pump and online using the IVPE (ONL+ONC). Competence in using the actual IV pump was assessed for all participants at the conclusion of the training period. No significant differences in learning outcomes, measured by assessment scores out of 80 points, were found between the ONL (M=65.5±9.2) and ONC (M=62.0±14.8; p>.05) groups. Significantly better learning outcomes were evident for the ONL+ONC group (M=68.7±4.9) compared to the ONC group (pstudents became more competent in the skill of preparing and administrating IV infusions when face-to-face and online learning were combined. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Varying assay geometry to emulate connective tissue planes in an in vitro model of acupuncture needling.

    Science.gov (United States)

    Julias, Margaret; Buettner, Helen M; Shreiber, David I

    2011-02-01

    During traditional acupuncture, fine needles are inserted subcutaneously and rotated, which causes loose fascial tissue to wind around the needle. This coupling is stronger at acupuncture points, which tend to fall above intermuscular fascial planes, than control points, which lay above skeletal muscle. These different anatomical constraints may affect the mechanical coupling. Fascia at acupuncture points is bounded on two sides by skeletal muscle, but at control points is essentially unbounded. These differences were approximated in simple in vitro models. To emulate the narrower boundary within the intermuscular plane, type I collagen was cast in circular gels of different radii. To model the channel-like nature of these planes, collagen was cast in elliptical gels with major and minor axes matching the large and small circular gels, respectively, and in planar gels constrained on two sides. Acupuncture needles were inserted into the gels and rotated via a computer-controlled motor while capturing the evolution of fiber alignment under cross-polarization. Small circular gels aligned faster, but failed earlier than large circular gels. Rotation in elliptical and planar gels generated more alignment-per-revolution than circular gels. Planar gels were particularly resistant to failure. Fiber alignment in circular gels was isotropic, but was stronger in the direction of the minor axis in elliptical and planar gels. In fibroblast-populated gels, cells followed the alignment of the collagen fibers, and also became denser in regions of stronger alignment. These results suggest that the anatomy at acupuncture points provides unique boundaries that accentuate the mechanical response to needle manipulation. 2010 Wiley-Liss, Inc.

  13. Flexible body control using neural networks

    Science.gov (United States)

    Mccullough, Claire L.

    1992-01-01

    Progress is reported on the control of Control Structures Interaction suitcase demonstrator (a flexible structure) using neural networks and fuzzy logic. It is concluded that while control by neural nets alone (i.e., allowing the net to design a controller with no human intervention) has yielded less than optimal results, the neural net trained to emulate the existing fuzzy logic controller does produce acceptible system responses for the initial conditions examined. Also, a neural net was found to be very successful in performing the emulation step necessary for the anticipatory fuzzy controller for the CSI suitcase demonstrator. The fuzzy neural hybrid, which exhibits good robustness and noise rejection properties, shows promise as a controller for practical flexible systems, and should be further evaluated.

  14. Using Wireless Network Coding to Replace a Wired with Wireless Backhaul

    DEFF Research Database (Denmark)

    Thomsen, Henning; De Carvalho, Elisabeth; Popovski, Petar

    2014-01-01

    of wireless emulated wire (WEW), based on two-way relaying and network coding. This setup leads to a new type of broadcast problem, with decoding conditions that are specific to the requirement for equivalence to the wired backhaul. We formulate and solve the associated optimization problems. The proposed...

  15. Reforging the Wedding Ring: Exploring a Semi-Artificial Model of Population for the United Kingdom with Gaussian process emulators

    Directory of Open Access Journals (Sweden)

    Viet Dung Cao

    2013-10-01

    Full Text Available Background: We extend the "Wedding Ring‟ agent-based model of marriage formation to include some empirical information on the natural population change for the United Kingdom together with behavioural explanations that drive the observed nuptiality trends. Objective: We propose a method to explore statistical properties of agent-based demographic models. By coupling rule-based explanations driving the agent-based model with observed data we wish to bring agent-based modelling and demographic analysis closer together. Methods: We present a Semi-Artificial Model of Population, which aims to bridge demographic micro-simulation and agent-based traditions. We then utilise a Gaussian process emulator - a statistical model of the base model - to analyse the impact of selected model parameters on two key model outputs: population size and share of married agents. A sensitivity analysis is attempted, aiming to assess the relative importance of different inputs. Results: The resulting multi-state model of population dynamics has enhanced predictive capacity as compared to the original specification of the Wedding Ring, but there are some trade-offs between the outputs considered. The sensitivity analysis allows identification of the most important parameters in the modelled marriage formation process. Conclusions: The proposed methods allow for generating coherent, multi-level agent-based scenarios aligned with some aspects of empirical demographic reality. Emulators permit a statistical analysis of their properties and help select plausible parameter values. Comments: Given non-linearities in agent-based models such as the Wedding Ring, and the presence of feedback loops, the uncertainty in the model may not be directly computable by using traditional statistical methods. The use of statistical emulators offers a way forward.

  16. Conjunctively optimizing flash flood control and water quality in urban water reservoirs by model predictive control and dynamic emulation

    Science.gov (United States)

    Galelli, Stefano; Goedbloed, Albert; Schmitter, Petra; Castelletti, Andrea

    2014-05-01

    Urban water reservoirs are a viable adaptation option to account for increasing drinking water demand of urbanized areas as they allow storage and re-use of water that is normally lost. In addition, the direct availability of freshwater reduces pumping costs and diversifies the portfolios of drinking water supply. Yet, these benefits have an associated twofold cost. Firstly, the presence of large, impervious areas increases the hydraulic efficiency of urban catchments, with short time of concentration, increased runoff rates, losses of infiltration and baseflow, and higher risk of flash floods. Secondly, the high concentration of nutrients and sediments characterizing urban discharges is likely to cause water quality problems. In this study we propose a new control scheme combining Model Predictive Control (MPC), hydro-meteorological forecasts and dynamic model emulation to design real-time operating policies that conjunctively optimize water quantity and quality targets. The main advantage of this scheme stands in its capability of exploiting real-time hydro-meteorological forecasts, which are crucial in such fast-varying systems. In addition, the reduced computational requests of the MPC scheme allows coupling it with dynamic emulators of water quality processes. The approach is demonstrated on Marina Reservoir, a multi-purpose reservoir located in the heart of Singapore and characterized by a large, highly urbanized catchment with a short (i.e. approximately one hour) time of concentration. Results show that the MPC scheme, coupled with a water quality emulator, provides a good compromise between different operating objectives, namely flood risk reduction, drinking water supply and salinity control. Finally, the scheme is used to assess the effect of source control measures (e.g. green roofs) aimed at restoring the natural hydrological regime of Marina Reservoir catchment.

  17. Multi-level emulation of a volcanic ash transport and dispersion model to quantify sensitivity to uncertain parameters

    Science.gov (United States)

    Harvey, Natalie J.; Huntley, Nathan; Dacre, Helen F.; Goldstein, Michael; Thomson, David; Webster, Helen

    2018-01-01

    Following the disruption to European airspace caused by the eruption of Eyjafjallajökull in 2010 there has been a move towards producing quantitative predictions of volcanic ash concentration using volcanic ash transport and dispersion simulators. However, there is no formal framework for determining the uncertainties of these predictions and performing many simulations using these complex models is computationally expensive. In this paper a Bayesian linear emulation approach is applied to the Numerical Atmospheric-dispersion Modelling Environment (NAME) to better understand the influence of source and internal model parameters on the simulator output. Emulation is a statistical method for predicting the output of a computer simulator at new parameter choices without actually running the simulator. A multi-level emulation approach is applied using two configurations of NAME with different numbers of model particles. Information from many evaluations of the computationally faster configuration is combined with results from relatively few evaluations of the slower, more accurate, configuration. This approach is effective when it is not possible to run the accurate simulator many times and when there is also little prior knowledge about the influence of parameters. The approach is applied to the mean ash column loading in 75 geographical regions on 14 May 2010. Through this analysis it has been found that the parameters that contribute the most to the output uncertainty are initial plume rise height, mass eruption rate, free tropospheric turbulence levels and precipitation threshold for wet deposition. This information can be used to inform future model development and observational campaigns and routine monitoring. The analysis presented here suggests the need for further observational and theoretical research into parameterisation of atmospheric turbulence. Furthermore it can also be used to inform the most important parameter perturbations for a small operational

  18. Multi-level emulation of a volcanic ash transport and dispersion model to quantify sensitivity to uncertain parameters

    Directory of Open Access Journals (Sweden)

    N. J. Harvey

    2018-01-01

    Full Text Available Following the disruption to European airspace caused by the eruption of Eyjafjallajökull in 2010 there has been a move towards producing quantitative predictions of volcanic ash concentration using volcanic ash transport and dispersion simulators. However, there is no formal framework for determining the uncertainties of these predictions and performing many simulations using these complex models is computationally expensive. In this paper a Bayesian linear emulation approach is applied to the Numerical Atmospheric-dispersion Modelling Environment (NAME to better understand the influence of source and internal model parameters on the simulator output. Emulation is a statistical method for predicting the output of a computer simulator at new parameter choices without actually running the simulator. A multi-level emulation approach is applied using two configurations of NAME with different numbers of model particles. Information from many evaluations of the computationally faster configuration is combined with results from relatively few evaluations of the slower, more accurate, configuration. This approach is effective when it is not possible to run the accurate simulator many times and when there is also little prior knowledge about the influence of parameters. The approach is applied to the mean ash column loading in 75 geographical regions on 14 May 2010. Through this analysis it has been found that the parameters that contribute the most to the output uncertainty are initial plume rise height, mass eruption rate, free tropospheric turbulence levels and precipitation threshold for wet deposition. This information can be used to inform future model development and observational campaigns and routine monitoring. The analysis presented here suggests the need for further observational and theoretical research into parameterisation of atmospheric turbulence. Furthermore it can also be used to inform the most important parameter perturbations

  19. Subspace projection method for unstructured searches with noisy quantum oracles using a signal-based quantum emulation device

    Science.gov (United States)

    La Cour, Brian R.; Ostrove, Corey I.

    2017-01-01

    This paper describes a novel approach to solving unstructured search problems using a classical, signal-based emulation of a quantum computer. The classical nature of the representation allows one to perform subspace projections in addition to the usual unitary gate operations. Although bandwidth requirements will limit the scale of problems that can be solved by this method, it can nevertheless provide a significant computational advantage for problems of limited size. In particular, we find that, for the same number of noisy oracle calls, the proposed subspace projection method provides a higher probability of success for finding a solution than does an single application of Grover's algorithm on the same device.

  20. Emulsões múltiplas: formação e aplicação em microencapsulamento de componentes bioativos

    Directory of Open Access Journals (Sweden)

    Luciano José Barreto Pereira

    2015-01-01

    Full Text Available Emulsões múltiplas têm sido reconhecidas como uma nova tecnologia para as indústrias de alimentos. Devido a sua estrutura diferenciada dos demais sistemas coloidais, ou seja, existência de duas fases dispersas, esse grupo de emulsão apresenta vantagens em relação às emulsões convencionais, principalmente, no que se refere ao encapsulamento, à proteção e à liberação controlada de componentes bioativos. Assim, a estabilidade e a biodisponibilidade dos encapsulados podem ser aumentadas ou otimizadas, fato que possibilita o planejamento de melhores resultados pela indústria, por meio da produção de novos alimentos. Ainda, com a perspectiva de aumentar o valor nutricional de muitos alimentos industrializados, infere-se uma maior contribuição deles para a promoção da saúde e para prevenção e tratamento de certas doenças crônico-degenerativas. A presente revisão apresenta as bases da tecnologia usual de elaboração de emulsão múltipla, os principais processos de instabilidade a que esse sistema está susceptível, e a aplicação de emulsões múltiplas como sistemas encapsuladores e transportadores de componentes bioativos.

  1. Produção de cerâmicas celulares por emulsão seguida de gelificação Production of cellular ceramics by gel casting ceramic emulsions

    Directory of Open Access Journals (Sweden)

    E. de Sousa

    2011-03-01

    Full Text Available As cerâmicas celulares têm sido produzidas por diferentes métodos, resultando em uma ampla faixa de estruturas e propriedades. Este trabalho descreve uma nova rota para a produção de cerâmicas celulares, a qual se baseia na gelificação de emulsões constituídas de suspensões cerâmicas aquosas contendo monômeros orgânicos solúveis em água e uma fase líquida apolar emulsificada (querosene. Os efeitos do teor de sólidos e da fração de querosene nas propriedades reológicas das emulsões foram avaliados. A estrutura celular foi analisada por microscopia eletrônica de varredura e revelou poros isolados nas amostras de baixa porosidade, os quais mudaram para uma rede interconectada de poros com o aumento da porosidade. Compressão diametral foi usada para avaliar a resistência mecânica das amostras sinterizadas, a qual variou entre 2,0 e 48 MPa, dependendo da porosidade.Cellular ceramics have been produced by several methods, resulting in a wide range of structures and properties. This work describes a novel route to produce cellular ceramics based on the gel casting of emulsions consisting of an aqueous ceramic suspension containing water-soluble organic monomers and an emulsified insoluble liquid phase (kerosene. The effects of solids loading and kerosene content on the rheological properties of emulsions were evaluated. SEM of the cellular structure revealed isolated pores for samples with low porosity, which changed to an interconnected network of pores as the porosity increased. Diametrical compression was used to evaluate the strength of sintered samples, which varied in the range of 2.0 and 48 MPa, depending on the porosity.

  2. FPGA-Based Vehicular Channel Emulator for Real-Time Performance Evaluation of IEEE 802.11p Transceivers

    Directory of Open Access Journals (Sweden)

    Fernández-Caramés TM

    2010-01-01

    Full Text Available IEEE 802.11p is one of the most promising future wireless standards due to the increasing demand of vehicular communication applications. At the time of writing, the document of the standard is in draft and much research is still required to study and improve the performance of transceivers in common vehicular scenarios. In this paper, we present a framework to evaluate the PHY layer of IEEE 802.11p systems in realistic situations. We detail the design and implementation of an FPGA-based real-time vehicular channel emulator. Contrarily to commercial emulators, ours is cheap, very flexible, and reconfigurable. We show its capabilities by evaluating performance in different high-speed scenarios. We also study the importance of coding and the benefits of using IEEE 802.11p instead of IEEE 802.11a in vehicular environments. Towards this aim, we developed a reference IEEE 802.11p PHY transceiver software model that can be taken as a convenient starting point for transceiver design.

  3. AC Transmission Emulation Control Strategies for the BTB VSC HVDC System in the Metropolitan Area of Seoul

    Directory of Open Access Journals (Sweden)

    Sungyoon Song

    2017-08-01

    Full Text Available In the Korean power system, growing power loads have recently created the problems of voltage instability and fault current in the Seoul Capital Area (SCA. Accordingly, the back-to-back (BTB voltage source converter (VSC high-voltage direct-current (HVDC system is emerging to resolve such problems with grid segmentation. However, non-convergence problems occur in this metropolitan area, due to the large change of power flow in some contingencies. Therefore, this paper proposes two kinds of AC transmission emulation control (ATEC strategies to improve the metropolitan transient stability, and to resolve the non-convergence problem. The proposed ATEC strategies are able to mitigate possible overloading of adjacent AC transmission, and maintain power balance between metropolitan regions. The first ATEC strategy uses a monitoring system that permits the reverse power flow of AC transmission, and thus effectively improves the grid stability based on the power transfer equation. The second ATEC strategy emulates AC transmission with DC link capacitors in a permissible DC-link voltage range according to angle difference, and securely improves the gird stability, without requiring grid operator schedule decisions. This paper compares two kinds of ATEC schemes: it demonstrates the first ATEC strategy with specific fault scenario with PSS/E (Power Transmission System Planning Software, and evaluates the second ATEC strategy with internal controller performance with PSCAD/EMTDC (Power System Electromagnetic Transients Simulation Software.

  4. Enabling software defined networking experiments in networked critical infrastructures

    Directory of Open Access Journals (Sweden)

    Béla Genge

    2014-05-01

    Full Text Available Nowadays, the fact that Networked Critical Infrastructures (NCI, e.g., power plants, water plants, oil and gas distribution infrastructures, and electricity grids, are targeted by significant cyber threats is well known. Nevertheless, recent research has shown that specific characteristics of NCI can be exploited in the enabling of more efficient mitigation techniques, while novel techniques from the field of IP networks can bring significant advantages. In this paper we explore the interconnection of NCI communication infrastructures with Software Defined Networking (SDN-enabled network topologies. SDN provides the means to create virtual networking services and to implement global networking decisions. It relies on OpenFlow to enable communication with remote devices and has been recently categorized as the “Next Big Technology”, which will revolutionize the way decisions are implemented in switches and routers. Therefore, the paper documents the first steps towards enabling an SDN-NCI and presents the impact of a Denial of Service experiment over traffic resulting from an XBee sensor network which is routed across an emulated SDN network.

  5. Development of a Universal Networked Timer at NSTX

    Energy Technology Data Exchange (ETDEWEB)

    Sichta, P.; Dong, J.; Lawson, J. E.; Oliaro, G.; Wertenbaker, J.

    2005-09-23

    A new Timing and Synchronization System component, the Universal Networked Timer (UNT), is under development at the National Spherical Torus Experiment (NSTX). The UNT is a second-generation multifunction timing device that emulates the timing functionality and electrical interfaces originally provided by various CAMAC modules. Using Field Programmable Gate Array (FPGA) technology, each of the UNT's eight channels can be dynamically programmed to emulate a specific CAMAC module type. The timer is compatible with the existing NSTX timing and synchronization system and will also support a (future) clock system with extended performance. To assist system designers and collaborators, software will be written to integrate the UNT with EPICS, MDSplus, and LabVIEW. This paper will describe the timing capabilities, hardware design, programming/software support, and the current status of the Universal Networked Timer at NSTX.

  6. Neuromorphic atomic switch networks.

    Directory of Open Access Journals (Sweden)

    Audrius V Avizienis

    Full Text Available Efforts to emulate the formidable information processing capabilities of the brain through neuromorphic engineering have been bolstered by recent progress in the fabrication of nonlinear, nanoscale circuit elements that exhibit synapse-like operational characteristics. However, conventional fabrication techniques are unable to efficiently generate structures with the highly complex interconnectivity found in biological neuronal networks. Here we demonstrate the physical realization of a self-assembled neuromorphic device which implements basic concepts of systems neuroscience through a hardware-based platform comprised of over a billion interconnected atomic-switch inorganic synapses embedded in a complex network of silver nanowires. Observations of network activation and passive harmonic generation demonstrate a collective response to input stimulus in agreement with recent theoretical predictions. Further, emergent behaviors unique to the complex network of atomic switches and akin to brain function are observed, namely spatially distributed memory, recurrent dynamics and the activation of feedforward subnetworks. These devices display the functional characteristics required for implementing unconventional, biologically and neurally inspired computational methodologies in a synthetic experimental system.

  7. Experimental demonstration of an improved EPON architecture using OFDMA for bandwidth scalable LAN emulation

    DEFF Research Database (Denmark)

    Deng, Lei; Zhao, Ying; Yu, Xianbin

    2011-01-01

    , there is no need to change the existing EPON architecture. Only one receiver at each optical network unit (ONU) is required to detect both LAN traffic and EPON downstream traffic, which makes the proposed system simple and cost-effective. Moreover, flexible assignment of LAN traffic bandwidth is realized...

  8. A generic inertia emulation controller for multi-terminal VSC-HVDC systems

    DEFF Research Database (Denmark)

    Zhu, Jiebei; Guerrero, Josep M.; Booth, Campbell

    2013-01-01

    implementation to the conventional VSC control system are presented, and the impact of total DC capacitance of the MTDC network on DC voltage variations is discussed. The proposed INEC for MTDC systems are validated by Matlab/Simulink under demand changes in a simulated multi-machine power system with a MTDC...

  9. Intra and Inter-PON ONU to ONU Virtual Private Networking using OFDMA in a Ring Topology

    DEFF Research Database (Denmark)

    Deng, Lei; Zhao, Ying; Pang, Xiaodan

    2011-01-01

    Abstract—In this paper, we propose a novel WDM-PON architecture to support efficient and bandwidth-scalable virtual private network (VPN) emulation over both inter-PON and intra- PON. The virtual ring link for the VPN communications among ONUs is realized by using additionally low-cost optical...

  10. Simulation and Modeling of a New Medium Access Control Scheme for Multi-Beam Directional Networking

    Science.gov (United States)

    2017-03-03

    implement our protocol in both simula- tion and a new Extendable Mobile Ad -hoc Network Emula- tor (EMANE) model that allows for real-time, high fidelity...issues, where the amount of data passed between the servers is too high, and 2) computation issues, where calculating the interference on the packets...developed a custom discrete event simulator in C++, and a new Ex- tendable Mobile Ad -hoc Network Emulator (EMANE) [10] model. These tools are used to both

  11. Emulating atmosphere-ocean and carbon cycle models with a simpler model, MAGICC6 – Part 2: Applications

    Directory of Open Access Journals (Sweden)

    M. Meinshausen

    2011-02-01

    Full Text Available Intercomparisons of coupled atmosphere-ocean general circulation models (AOGCMs and carbon cycle models are important for galvanizing our current scientific knowledge to project future climate. Interpreting such intercomparisons faces major challenges, not least because different models have been forced with different sets of forcing agents. Here, we show how an emulation approach with MAGICC6 can address such problems. In a companion paper (Meinshausen et al., 2011a, we show how the lower complexity carbon cycle-climate model MAGICC6 can be calibrated to emulate, with considerable accuracy, globally aggregated characteristics of these more complex models. Building on that, we examine here the Coupled Model Intercomparison Project's Phase 3 results (CMIP3. If forcing agents missed by individual AOGCMs in CMIP3 are considered, this reduces ensemble average temperature change from pre-industrial times to 2100 under SRES A1B by 0.4 °C. Differences in the results from the 1980 to 1999 base period (as reported in IPCC AR4 to 2100 are negligible, however, although there are some differences in the trajectories over the 21st century. In a second part of this study, we consider the new RCP scenarios that are to be investigated under the forthcoming CMIP5 intercomparison for the IPCC Fifth Assessment Report. For the highest scenario, RCP8.5, relative to pre-industrial levels, we project a median warming of around 4.6 °C by 2100 and more than 7 °C by 2300. For the lowest RCP scenario, RCP3-PD, the corresponding warming is around 1.5 °C by 2100, decreasing to around 1.1 °C by 2300 based on our AOGCM and carbon cycle model emulations. Implied cumulative CO2 emissions over the 21st century for RCP8.5 and RCP3-PD are 1881 GtC (1697 to 2034 GtC, 80% uncertainty range and 381 GtC (334 to 488 GtC, when prescribing CO2 concentrations and accounting for uncertainty in the carbon cycle. Lastly, we assess the reasons why a previous MAGICC

  12. Estudo experimental e modelagem do escoamento de emulsão inversa em tubulações

    OpenAIRE

    Iara Hernandez Rodriguez

    2014-01-01

    O escoamento líquido-líquido, em especial o escoamento óleo-água, vem atraindo a atenção de pesquisadores devido à alta demanda pelo combustível fóssil no atual cenário petrolífero mundial e nacional. Os desafios tecnológicos colocados pelas descobertas de reservas de óleos pesados e altamente viscosos consideram, em especial, a preocupação por minimizar as perdas energéticas nas linhas. Emulsões inversas ou dispersões óleo-em-água, na qual o óleo se encontra disperso de maneira uniforme em á...

  13. Emulating the Level-1 Electromagnetic Trigger Response Using an Offline Database. Procedure for Populating This Database from the Online Information.

    CERN Document Server

    Becheva, Emilia

    2010-01-01

    The Level-1 Trigger plays a major role in the CMS experiment allowing to reduce the raw event rate at the Large Hadron Collider. Its decision is based on information from the electromagnetic and hadronic calorimeters as well as the muon detectors. The electronics of the electromagnetic calorimeter generate and deliver basic quantities called "Trigger Primitives" which correspond to local energy deposits created by electromagnetic showers. In order to ensure the correct generation of the trigger primitives by the electronics, a special software (emulator) has been implemented. It is able to reproduce the ECAL trigger functionalities at the bit level using the same inputs and identical output format. It is configured in exactly the same way as the hardware. The configuration of the electromagnetic hardware trigger requires 5 million parameters stored into an Online Master Data Storage database (OMDS). This poster will present the procedure used to transfer the parameters from the OMDS to the Offline datab...

  14. Increased long-latency reflex activity as a sufficient explanation for childhood hypertonic dystonia: a neuromorphic emulation study

    Science.gov (United States)

    Sohn, Won J.; Niu, Chuanxin M.; Sanger, Terence D.

    2015-06-01

    Objective. Childhood dystonia is a movement disorder that interferes with daily movements and can have a devastating effect on quality of life for children and their families. Although injury to basal ganglia is associated with dystonia, the neurophysiological mechanisms leading to the clinical manifestations of dystonia are not understood. Previous work suggested that long-latency stretch reflex (LLSR) is hyperactive in children with hypertonia due to secondary dystonia. We hypothesize that abnormal activity in motor cortices may cause an increase in the LLSR leading to hypertonia. Approach. We modeled two possibilities of hyperactive LLSR by either creating a tonic involuntary drive to cortex, or increasing the synaptic gain in cortical neurons. Both models are emulated using programmable very-large-scale-integrated-circuit hardware to test their sufficiency for producing dystonic symptoms. The emulation includes a joint with two Hill-type muscles, realistic muscle spindles, and 2,304 Izhikevich-type spiking neurons. The muscles are regulated by a monosynaptic spinal pathway with 32 ms delay and a long-latency pathway with 64 ms loop-delay representing transcortical/supra-spinal connections. Main results. When the limb is passively stretched, both models produce involuntary resistance with increased antagonist EMG responses similar to human data; also the muscle relaxation is delayed similar to human data. Both models predict reduced range of motion in voluntary movements. Significance. Although our model is a highly simplified and limited representation of reflex pathways, it shows that increased activity of the LLSR is by itself sufficient to cause many of the features of hypertonic dystonia.

  15. Bayesian uncertainty analysis for complex systems biology models: emulation, global parameter searches and evaluation of gene functions.

    Science.gov (United States)

    Vernon, Ian; Liu, Junli; Goldstein, Michael; Rowe, James; Topping, Jen; Lindsey, Keith

    2018-01-02

    Many mathematical models have now been employed across every area of systems biology. These models increasingly involve large numbers of unknown parameters, have complex structure which can result in substantial evaluation time relative to the needs of the analysis, and need to be compared to observed data of various forms. The correct analysis of such models usually requires a global parameter search, over a high dimensional parameter space, that incorporates and respects the most important sources of uncertainty. This can be an extremely difficult task, but it is essential for any meaningful inference or prediction to be made about any biological system. It hence represents a fundamental challenge for the whole of systems biology. Bayesian statistical methodology for the uncertainty analysis of complex models is introduced, which is designed to address the high dimensional global parameter search problem. Bayesian emulators that mimic the systems biology model but which are extremely fast to evaluate are embeded within an iterative history match: an efficient method to search high dimensional spaces within a more formal statistical setting, while incorporating major sources of uncertainty. The approach is demonstrated via application to a model of hormonal crosstalk in Arabidopsis root development, which has 32 rate parameters, for which we identify the sets of rate parameter values that lead to acceptable matches between model output and observed trend data. The multiple insights into the model's structure that this analysis provides are discussed. The methodology is applied to a second related model, and the biological consequences of the resulting comparison, including the evaluation of gene functions, are described. Bayesian uncertainty analysis for complex models using both emulators and history matching is shown to be a powerful technique that can greatly aid the study of a large class of systems biology models. It both provides insight into model behaviour

  16. Emulating natural disturbances for declining late-successional species: A case study of the consequences for Cerulean Warblers (Setophaga cerulea)

    Science.gov (United States)

    Boves, Than J.; Buehler, David A.; Sheehan, James; Wood, Petra Bohall; Rodewald, Amanda D.; Larkin, Jeffrey L.; Keyser, Patrick D.; Newell, Felicity L.; George, Gregory A.; Bakermans, Marja H.; Evans, Andrea; Beachy, Tiffany A.; McDermott, Molly E.; Perkins, Kelly A.; White, Matthew; Wigley, T. Bently

    2013-01-01

    Forest cover in the eastern United States has increased over the past century and while some late-successional species have benefited from this process as expected, others have experienced population declines. These declines may be in part related to contemporary reductions in small-scale forest interior disturbances such as fire, windthrow, and treefalls. To mitigate the negative impacts of disturbance alteration and suppression on some late-successional species, strategies that emulate natural disturbance regimes are often advocated, but large-scale evaluations of these practices are rare. Here, we assessed the consequences of experimental disturbance (using partial timber harvest) on a severely declining late-successional species, the cerulean warbler (Setophaga cerulea), across the core of its breeding range in the Appalachian Mountains. We measured numerical (density), physiological (body condition), and demographic (age structure and reproduction) responses to three levels of disturbance and explored the potential impacts of disturbance on source-sink dynamics. Breeding densities of warblers increased one to four years after all canopy disturbances (vs. controls) and males occupying territories on treatment plots were in better condition than those on control plots. However, these beneficial effects of disturbance did not correspond to improvements in reproduction; nest success was lower on all treatment plots than on control plots in the southern region and marginally lower on light disturbance plots in the northern region. Our data suggest that only habitats in the southern region acted as sources, and interior disturbances in this region have the potential to create ecological traps at a local scale, but sources when viewed at broader scales. Thus, cerulean warblers would likely benefit from management that strikes a landscape-level balance between emulating natural disturbances in order to attract individuals into areas where current structure is

  17. Synesthesia, sensory-motor contingency, and semantic emulation: how swimming style-color synesthesia challenges the traditional view of synesthesia.

    Science.gov (United States)

    Mroczko-Wąsowicz, Aleksandra; Werning, Markus

    2012-01-01

    Synesthesia is traditionally regarded as a phenomenon in which an additional non-standard phenomenal experience occurs consistently in response to ordinary stimulation applied to the same or another modality. Recent studies suggest an important role of semantic representations in the induction of synesthesia. In the present proposal we try to link the empirically grounded theory of sensory-motor contingency and mirror system based embodied simulation/emulation to newly discovered cases of swimming style-color synesthesia. In the latter color experiences are evoked only by showing the synesthetes a picture of a swimming person or asking them to think about a given swimming style. Neural mechanisms of mirror systems seem to be involved here. It has been shown that for mirror-sensory synesthesia, such as mirror-touch or mirror-pain synesthesia (when visually presented tactile or noxious stimulation of others results in the projection of the tactile or pain experience onto oneself), concurrent experiences are caused by overactivity in the mirror neuron system responding to the specific observation. The comparison of different forms of synesthesia has the potential of challenging conventional thinking on this phenomenon and providing a more general, sensory-motor account of synesthesia encompassing cases driven by semantic or emulational rather than pure sensory or motor representations. Such an interpretation could include top-down associations, questioning the explanation in terms of hard-wired structural connectivity. In the paper the hypothesis is developed that the wide-ranging phenomenon of synesthesia might result from a process of hyperbinding between "too many" semantic attribute domains. This hypothesis is supplemented by some suggestions for an underlying neural mechanism.

  18. Evolutionary Algorithms For Neural Networks Binary And Real Data Classification

    Directory of Open Access Journals (Sweden)

    Dr. Hanan A.R. Akkar

    2015-08-01

    Full Text Available Artificial neural networks are complex networks emulating the way human rational neurons process data. They have been widely used generally in prediction clustering classification and association. The training algorithms that used to determine the network weights are almost the most important factor that influence the neural networks performance. Recently many meta-heuristic and Evolutionary algorithms are employed to optimize neural networks weights to achieve better neural performance. This paper aims to use recently proposed algorithms for optimizing neural networks weights comparing these algorithms performance with other classical meta-heuristic algorithms used for the same purpose. However to evaluate the performance of such algorithms for training neural networks we examine such algorithms to classify four opposite binary XOR clusters and classification of continuous real data sets such as Iris and Ecoli.

  19. Information communication on complex networks

    Science.gov (United States)

    Igarashi, Akito; Kawamoto, Hiroki; Maruyama, Takahiro; Morioka, Atsushi; Naganuma, Yuki

    2013-02-01

    Since communication networks such as the Internet, which is regarded as a complex network, have recently become a huge scale and a lot of data pass through them, the improvement of packet routing strategies for transport is one of the most significant themes in the study of computer networks. It is especially important to find routing strategies which can bear as many traffic as possible without congestion in complex networks. First, using neural networks, we introduce a strategy for packet routing on complex networks, where path lengths and queue lengths in nodes are taken into account within a framework of statistical physics. Secondly, instead of using shortest paths, we propose efficient paths which avoid hubs, nodes with a great many degrees, on scale-free networks with a weight of each node. We improve the heuristic algorithm proposed by Danila et. al. which optimizes step by step routing properties on congestion by using the information of betweenness, the probability of paths passing through a node in all optimal paths which are defined according to a rule, and mitigates the congestion. We confirm the new heuristic algorithm which balances traffic on networks by achieving minimization of the maximum betweenness in much smaller number of iteration steps. Finally, We model virus spreading and data transfer on peer-to-peer (P2P) networks. Using mean-field approximation, we obtain an analytical formulation and emulate virus spreading on the network and compare the results with those of simulation. Moreover, we investigate the mitigation of information traffic congestion in the P2P networks.

  20. Network Science Research Laboratory (NSRL) Telemetry Warehouse

    Science.gov (United States)

    2016-06-01

    Collection, Storage, and Retrieval 3 3.2 Comparative Analysis 4 3.3 Data Processing 4 4. Architecture 4 4.1 NTW Database 6 4.2 NTW Server 6 4.4...efforts between ARL and the US Naval Research Laboratory (NRL). The primary emulation tools used by ARL are the Extendable Mobile Ad -Hoc Network...procedure call (gRPC) system. The gRPC system uses the Google protocol buffers compiler to generate the code for the server . gRPC handles many of the basic

  1. A Network Traffic Generator Model for Fast Network-on-Chip Simulation

    DEFF Research Database (Denmark)

    Mahadevan, Shankar; Angiolini, Frederico; Storgaard, Michael

    2005-01-01

    and effective Network-on-Chip (NoC) development and debugging environment. By capturing the type and the timestamp of communication events at the boundary of an IP core in a reference environment, the TG can subsequently emulate the core's communication behavior in different environments. Access patterns......For Systems-on-Chip (SoCs) development, a predominant part of the design time is the simulation time. Performance evaluation and design space exploration of such systems in bit- and cycle-true fashion is becoming prohibitive. We propose a traffic generation (TG) model that provides a fast...

  2. Network Traffic Generator Model for Fast Network-on-Chip Simulation

    DEFF Research Database (Denmark)

    Mahadevan, Shankar; Ang, Frederico; Olsen, Rasmus G.

    2008-01-01

    and effective Network-on-Chip (NoC) development and debugging environment. By capturing the type and the timestamp of communication events at the boundary of an IP core in a reference environment, the TG can subsequently emulate the core's communication behavior in different environments. Access patterns......For Systems-on-Chip (SoCs) development, a predominant part of the design time is the simulation time. Performance evaluation and design space exploration of such systems in bit- and cycle-true fashion is becoming prohibitive. We propose a traffic generation (TG) model that provides a fast...

  3. New evaluation concept of the Athena WFI camera system by emulation of X-ray DEPFET detectors

    Science.gov (United States)

    Ott, S.; Bähr, A.; Brand, T.; Dauser, T.; Meidinger, N.; Plattner, M.; Stechele, W.

    2016-01-01

    The Wide Field Imager (WFI) is an X-ray camera for the future observatory Athena as the next ESA L-class mission. The signal processing chain of the WFI reaches from the sensing of incoming photons to the telemetry transmission to the spacecraft. Up to now the signal processing chain is verified with measurements of real X-ray sources, thus only limited test scenarios are possible. This paper presents a new concept for evaluating the X-ray camera system. Therefore a new end-to-end evaluation is proposed, which makes use of a programmable real-time emulator of the WFI DEPFET detector system including front-end electronics. With a complete variation of all available input parameters significant characteristics of the camera system can be studied and evaluated. This end-to-end evaluation method is a powerful tool to support the development of the WFI camera setup not only in the early stage, but also to improve characteristics and complex processing algorithms of the WFI when it will be in orbit.

  4. SolEmuls-novel technology for the formulation of i.v. emulsions with poorly soluble drugs.

    Science.gov (United States)

    Müller, R H; Schmidt, S; Buttle, I; Akkar, A; Schmitt, J; Brömer, S

    2004-01-28

    Intravenously injectable o/w emulsions of drugs being poorly soluble in water and simultaneously in oils need to be produced by locating the drug in the interfacial lecithin layer, e.g. amphotericin B. For achieving this, up to now organic solvents were required. The objective was to develop a solvent-free production method for such emulsions. Drug and the pre-formed parenteral emulsion Lipofundin were mixed and subjected to high pressure homogenisation. Drug powder and emulsions were characterised regarding size and physical stability by photon correlation spectroscopy (PCS), laser diffractometry (LD) and zeta potential measurements. Drug incorporation was studied using light microscopy, electron microscopy (EM) and a centrifugation test to separate non-dissolved drug. Amphotericin B and carbamazepine were used as model drugs. The high streaming velocities lead to accelerated drug dissolution and partitioning into the interfacial layer (so-called "solubilisation by emulsification", SolEmuls Technology). The interfacial layer could incorporate (solubilise) a certain amount of drug, revealed by EM pictures. Exceeding this concentration, hybrid dispersions were formed consisting of drug-loaded oil droplets and drug nanocrystals of similar size (approximately 200 nm). Both dispersion types are i.v. injectable opening the opportunity to deliver the drug in a concentrated form at desired low injection volume, e.g. 10 mg/ml.

  5. Synesthesia, sensory-motor contingency and semantic emulation: How swimming style-color synesthesia challenges the traditional view of synesthesia

    Directory of Open Access Journals (Sweden)

    Aleksandra eMroczko-Wąsowicz

    2012-08-01

    Full Text Available Synesthesia is a phenomenon in which an additional nonstandard perceptual experience occurs consistently in response to ordinary stimulation applied to the same or another modality. Recent studies suggest an important role of semantic representations in the induction of synesthesia. In the present proposal we try to link the empirically grounded theory of sensory-motor contingency and mirror system based embodied simulation to newly discovered cases of swimming-style color synesthesia. In the latter color experiences are evoked only by showing the synesthetes a picture of a swimming person or asking them to think about a given swimming style. Neural mechanisms of mirror systems seem to be involved here. It has been shown that for mirror-sensory synesthesia, such as mirror-touch or mirror-pain synesthesia, concurrent experiences are caused by the overactivity in the mirror neuron system responding to the specific observation. The comparison of different forms of synesthesia has the potential of challenging conventional thinking on this phenomenon and providing a more general, sensory-motor account of synesthesia encompassing cases driven by semantic or emulational rather than pure sensory or motor representations.

  6. Produção de cerâmicas celulares por emulsão seguida de gelificação

    OpenAIRE

    Sousa, E; M. Dellú Jr; Pandolfelli,V. C.; F. S. Ortega

    2011-01-01

    As cerâmicas celulares têm sido produzidas por diferentes métodos, resultando em uma ampla faixa de estruturas e propriedades. Este trabalho descreve uma nova rota para a produção de cerâmicas celulares, a qual se baseia na gelificação de emulsões constituídas de suspensões cerâmicas aquosas contendo monômeros orgânicos solúveis em água e uma fase líquida apolar emulsificada (querosene). Os efeitos do teor de sólidos e da fração de querosene nas propriedades reológicas das emulsões foram aval...

  7. Desenvolvimento de emulsões óleo de oliva/água: avaliação da estabilidade física

    Directory of Open Access Journals (Sweden)

    R. C.C. FRANGE

    2010-06-01

    Full Text Available

    Emulsões óleo de oliva/água, na presença de agentes emulsionantes não-iônicos, foram avaliadas quanto à estabilidade física. Assim, prepararam-se emulsões fazendo uso de diferentes emulsionantes, sendo um hidrofílico e o outro lipofílico, nas diferentes proporções. Às emulsões mais estáveis, adicionaram-se agentes auxiliares da emulsificação, visando otimizar a estabilidade; e estudos de estabilidade foram conduzidos, submetendo as amostras em condições e períodos diversos de armazenamento. Para caracterização da estabilidade, as amostras foram examinadas macroscopicamente e submetidas às análises de pH, centrifugação, viscosidade, potencial zeta e distribuição de tamanho de partícula. Os resultados demonstraram que as emulsões óleo de oliva/água não apresentaram alteração, ou seja mantiveram-se estáveis, quanto às propriedades organolépticas, bem como físico-químicas, quando armazenadas à temperatura ambiente e protegidas da luz. Das emulsões obtidas, as que apresentaram maior estabilidade provêm da associação de agentes emulsionantes que resultaram em equilíbrio hidrofílico-lipofílico (EHL equivalente a 12. As emulsões provenientes da associação de agentes emulsionantes que possuem cadeias de ácidos graxos insaturados similares ao óleo de oliva produziram estabilidade máxima, demonstrando que a similaridade estrutural entre os componentes da fase oleosa e os agentes emulsionantes é essencial para a estabilidade da emulsão. Palavras-chave: Emulsão O/A. Estabilidade. Óleo de Oliva. EHL. Emulsionante não-iônico. ABSTRACT Development of olive oil-in-water emulsions: assessment of physical stability Olive oil-in-water emulsions, developed with non-ionic emulsifiers, were assessed with regard to physical stability. Emulsions were prepared with two different emulsifiers, one of which was hydrophilic and the other lipophilic, in various proportions. To improve

  8. Appendices to the user's manual for a computer program for the emulation/simulation of a space station environmental control and life support system

    Science.gov (United States)

    Yanosy, James L.

    1988-01-01

    A user's Manual for the Emulation Simulation Computer Model was published previously. The model consisted of a detailed model (emulation) of a SAWD CO2 removal subsystem which operated with much less detailed (simulation) models of a cabin, crew, and condensing and sensible heat exchangers. The purpose was to explore the utility of such an emulation/simulation combination in the design, development, and test of a piece of ARS hardware - SAWD. Extensions to this original effort are presented. The first extension is an update of the model to reflect changes in the SAWD control logic which resulted from the test. In addition, slight changes were also made to the SAWD model to permit restarting and to improve the iteration technique. The second extension is the development of simulation models for more pieces of air and water processing equipment. Models are presented for: EDC, Molecular Sieve, Bosch, Sabatier, a new condensing heat exchanger, SPE, SFWES, Catalytic Oxidizer, and multifiltration. The third extension is to create two system simulations using these models. The first system presented consists of one air and one water processing system, the second a potential Space Station air revitalization system.

  9. Methods, Devices and Computer Program Products Providing for Establishing a Model for Emulating a Physical Quantity Which Depends on at Least One Input Parameter, and Use Thereof

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention proposes methods, devices and computer program products. To this extent, there is defined a set X including N distinct parameter values x_i for at least one input parameter x, N being an integer greater than or equal to 1, first measured the physical quantity Pm1 for each...... of the N distinct parameter values x_i of the at least one input parameter x, while keeping all other input parameters fixed, constructed a Vandermonde matrix VM using the set of N parameter values x_i of the at least one input parameter x, and computed the model W for emulating the physical quantity P...... based on the Vandermonde matrix and the first measured physical quantity according to the equation W=(VMT*VM)-1*VMT*Pm1. The model is iteratively refined so as to obtained a desired emulation precision.; The model can later be used to emulate the physical quantity based on input parameters or logs taken...

  10. Realistic computer network simulation for network intrusion detection dataset generation

    Science.gov (United States)

    Payer, Garrett

    2015-05-01

    The KDD-99 Cup dataset is dead. While it can continue to be used as a toy example, the age of this dataset makes it all but useless for intrusion detection research and data mining. Many of the attacks used within the dataset are obsolete and do not reflect the features important for intrusion detection in today's networks. Creating a new dataset encompassing a large cross section of the attacks found on the Internet today could be useful, but would eventually fall to the same problem as the KDD-99 Cup; its usefulness would diminish after a period of time. To continue research into intrusion detection, the generation of new datasets needs to be as dynamic and as quick as the attacker. Simply examining existing network traffic and using domain experts such as intrusion analysts to label traffic is inefficient, expensive, and not scalable. The only viable methodology is simulation using technologies including virtualization, attack-toolsets such as Metasploit and Armitage, and sophisticated emulation of threat and user behavior. Simulating actual user behavior and network intrusion events dynamically not only allows researchers to vary scenarios quickly, but enables online testing of intrusion detection mechanisms by interacting with data as it is generated. As new threat behaviors are identified, they can be added to the simulation to make quicker determinations as to the effectiveness of existing and ongoing network intrusion technology, methodology and models.

  11. Fuzzy neural networks: theory and applications

    Science.gov (United States)

    Gupta, Madan M.

    1994-10-01

    During recent years, significant advances have been made in two distinct technological areas: fuzzy logic and computational neural networks. The theory of fuzzy logic provides a mathematical framework to capture the uncertainties associated with human cognitive processes, such as thinking and reasoning. It also provides a mathematical morphology to emulate certain perceptual and linguistic attributes associated with human cognition. On the other hand, the computational neural network paradigms have evolved in the process of understanding the incredible learning and adaptive features of neuronal mechanisms inherent in certain biological species. Computational neural networks replicate, on a small scale, some of the computational operations observed in biological learning and adaptation. The integration of these two fields, fuzzy logic and neural networks, have given birth to an emerging technological field -- fuzzy neural networks. Fuzzy neural networks, have the potential to capture the benefits of these two fascinating fields, fuzzy logic and neural networks, into a single framework. The intent of this tutorial paper is to describe the basic notions of biological and computational neuronal morphologies, and to describe the principles and architectures of fuzzy neural networks. Towards this goal, we develop a fuzzy neural architecture based upon the notion of T-norm and T-conorm connectives. An error-based learning scheme is described for this neural structure.

  12. Distributed controller clustering in software defined networks.

    Directory of Open Access Journals (Sweden)

    Ahmed Abdelaziz

    Full Text Available Software Defined Networking (SDN is an emerging promising paradigm for network management because of its centralized network intelligence. However, the centralized control architecture of the software-defined networks (SDNs brings novel challenges of reliability, scalability, fault tolerance and interoperability. In this paper, we proposed a novel clustered distributed controller architecture in the real setting of SDNs. The distributed cluster implementation comprises of multiple popular SDN controllers. The proposed mechanism is evaluated using a real world network topology running on top of an emulated SDN environment. The result shows that the proposed distributed controller clustering mechanism is able to significantly reduce the average latency from 8.1% to 1.6%, the packet loss from 5.22% to 4.15%, compared to distributed controller without clustering running on HP Virtual Application Network (VAN SDN and Open Network Operating System (ONOS controllers respectively. Moreover, proposed method also shows reasonable CPU utilization results. Furthermore, the proposed mechanism makes possible to handle unexpected load fluctuations while maintaining a continuous network operation, even when there is a controller failure. The paper is a potential contribution stepping towards addressing the issues of reliability, scalability, fault tolerance, and inter-operability.

  13. Distributed controller clustering in software defined networks.

    Science.gov (United States)

    Abdelaziz, Ahmed; Fong, Ang Tan; Gani, Abdullah; Garba, Usman; Khan, Suleman; Akhunzada, Adnan; Talebian, Hamid; Choo, Kim-Kwang Raymond

    2017-01-01

    Software Defined Networking (SDN) is an emerging promising paradigm for network management because of its centralized network intelligence. However, the centralized control architecture of the software-defined networks (SDNs) brings novel challenges of reliability, scalability, fault tolerance and interoperability. In this paper, we proposed a novel clustered distributed controller architecture in the real setting of SDNs. The distributed cluster implementation comprises of multiple popular SDN controllers. The proposed mechanism is evaluated using a real world network topology running on top of an emulated SDN environment. The result shows that the proposed distributed controller clustering mechanism is able to significantly reduce the average latency from 8.1% to 1.6%, the packet loss from 5.22% to 4.15%, compared to distributed controller without clustering running on HP Virtual Application Network (VAN) SDN and Open Network Operating System (ONOS) controllers respectively. Moreover, proposed method also shows reasonable CPU utilization results. Furthermore, the proposed mechanism makes possible to handle unexpected load fluctuations while maintaining a continuous network operation, even when there is a controller failure. The paper is a potential contribution stepping towards addressing the issues of reliability, scalability, fault tolerance, and inter-operability.

  14. Bridging groundwater models and decision support with a Bayesian network

    Science.gov (United States)

    Fienen, Michael N.; Masterson, John P.; Plant, Nathaniel G.; Gutierrez, Benjamin T.; Thieler, E. Robert

    2013-01-01

    Resource managers need to make decisions to plan for future environmental conditions, particularly sea level rise, in the face of substantial uncertainty. Many interacting processes factor in to the decisions they face. Advances in process models and the quantification of uncertainty have made models a valuable tool for this purpose. Long-simulation runtimes and, often, numerical instability make linking process models impractical in many cases. A method for emulating the important connections between model input and forecasts, while propagating uncertainty, has the potential to provide a bridge between complicated numerical process models and the efficiency and stability needed for decision making. We explore this using a Bayesian network (BN) to emulate a groundwater flow model. We expand on previous approaches to validating a BN by calculating forecasting skill using cross validation of a groundwater model of Assateague Island in Virginia and Maryland, USA. This BN emulation was shown to capture the important groundwater-flow characteristics and uncertainty of the groundwater system because of its connection to island morphology and sea level. Forecast power metrics associated with the validation of multiple alternative BN designs guided the selection of an optimal level of BN complexity. Assateague island is an ideal test case for exploring a forecasting tool based on current conditions because the unique hydrogeomorphological variability of the island includes a range of settings indicative of past, current, and future conditions. The resulting BN is a valuable tool for exploring the response of groundwater conditions to sea level rise in decision support.

  15. High Fidelity Simulations of Large-Scale Wireless Networks

    Energy Technology Data Exchange (ETDEWEB)

    Onunkwo, Uzoma [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Benz, Zachary [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-11-01

    The worldwide proliferation of wireless connected devices continues to accelerate. There are 10s of billions of wireless links across the planet with an additional explosion of new wireless usage anticipated as the Internet of Things develops. Wireless technologies do not only provide convenience for mobile applications, but are also extremely cost-effective to deploy. Thus, this trend towards wireless connectivity will only continue and Sandia must develop the necessary simulation technology to proactively analyze the associated emerging vulnerabilities. Wireless networks are marked by mobility and proximity-based connectivity. The de facto standard for exploratory studies of wireless networks is discrete event simulations (DES). However, the simulation of large-scale wireless networks is extremely difficult due to prohibitively large turnaround time. A path forward is to expedite simulations with parallel discrete event simulation (PDES) techniques. The mobility and distance-based connectivity associated with wireless simulations, however, typically doom PDES and fail to scale (e.g., OPNET and ns-3 simulators). We propose a PDES-based tool aimed at reducing the communication overhead between processors. The proposed solution will use light-weight processes to dynamically distribute computation workload while mitigating communication overhead associated with synchronizations. This work is vital to the analytics and validation capabilities of simulation and emulation at Sandia. We have years of experience in Sandia’s simulation and emulation projects (e.g., MINIMEGA and FIREWHEEL). Sandia’s current highly-regarded capabilities in large-scale emulations have focused on wired networks, where two assumptions prevent scalable wireless studies: (a) the connections between objects are mostly static and (b) the nodes have fixed locations.

  16. Emulating a target trial of antiretroviral therapy regimens started before conception and risk of adverse birth outcomes.

    Science.gov (United States)

    Caniglia, Ellen C; Zash, Rebecca; Jacobson, Denise L; Diseko, Modiegi; Mayondi, Gloria; Lockman, Shahin; Chen, Jennifer; Mmalane, Mompati; Makhema, Joseph; Hernán, Miguel A; Shapiro, Roger L

    2017-11-02

    To compare the effect of pre-conception initiation of zidovudine, lamivudine, nevirapine (ZDV/3TC/NVP) versus tenofovir, emtricitabine, efavirenz (TDF/FTC/EFV) on adverse birth outcomes. Emulation of a hypothetical (target) trial using a birth surveillance study in Botswana during an era of CD4-based antiretroviral therapy (ART) initiation. In women who initiated ART EFV. We conducted a historical comparison in women who initiated TDF/FTC/EFV in 2012-2015 and ZDV/3TC/NVP in 2004-2011, and a contemporaneous comparison in an era of overlapping use from 2009-2013. In the historical comparison, 1108 women initiated TDF/FTC/EFV and 637 initiated ZDV/3TC/NVP. In the contemporaneous comparison, 1052 initiated TDF/FTC/EFV and 298 initiated ZDV/3TC/NVP. TDF/FTC/EFV initiators were younger and more likely to be nulliparous than ZDV/3TC/NVP initiators in both comparisons. In the historical comparison, the adjusted risk ratios (95% CI) comparing ZDV/3TC/NVP with TDF/FTC/EFV were 2.95 (1.76, 4.96) for stillbirth, 1.40 (1.17, 1.67) for preterm delivery, 2.58 (1.70, 3.91) for very preterm delivery, 1.96 (1.64, 2.34) for SGA, 2.32 (1.73, 3.09) for very SGA, 1.54 (1.38, 1.72) for any adverse birth outcome, and 2.20 (1.76, 2.75) for any severe birth outcome, and were similar in the contemporaneous comparison. Pre-conception initiation of ZDV/3TC/NVP compared with TDF/FTC/EFV may increase the risk of adverse birth outcomes.

  17. Emulation of the laparoscopic environment for image-guided liver surgery via an abdominal phantom system with anatomical ligamenture

    Science.gov (United States)

    Heiselman, Jon S.; Collins, Jarrod A.; Clements, Logan W.; Weis, Jared A.; Simpson, Amber L.; Geevarghese, Sunil K.; Jarnagin, William R.; Miga, Michael I.

    2017-03-01

    In order to rigorously validate techniques for image-guided liver surgery (IGLS), an accurate mock representation of the intraoperative surgical scene with quantifiable localization of subsurface targets would be highly desirable. However, many attempts to reproduce the laparoscopic environment have encountered limited success due to neglect of several crucial design aspects. The laparoscopic setting is complicated by factors such as gas insufflation of the abdomen, changes in patient orientation, incomplete organ mobilization from ligaments, and limited access to organ surface data. The ability to accurately represent the influences of anatomical changes and procedural limitations is critical for appropriate evaluation of IGLS methodologies such as registration and deformation correction. However, these influences have not yet been comprehensively integrated into a platform usable for assessment of methods in laparoscopic IGLS. In this work, a mock laparoscopic liver simulator was created with realistic ligamenture to emulate the complexities of this constrained surgical environment for the realization of laparoscopic IGLS. The mock surgical system reproduces an insufflated abdominal cavity with dissectible ligaments, variable levels of incline matching intraoperative patient positioning, and port locations in accordance with surgical protocol. True positions of targets embedded in a tissue-mimicking phantom are measured from CT images. Using this setup, image-to-physical registration accuracy was evaluated for simulations of laparoscopic right and left lobe mobilization to assess rigid registration performance under more realistic laparoscopic conditions. Preliminary results suggest that non-rigid organ deformations and the region of organ surface data collected affect the ability to attain highly accurate registrations in laparoscopic applications.

  18. Emulating Atlantic overturning strength for low emission scenarios: consequences for sea-level rise along the North American east coast

    Directory of Open Access Journals (Sweden)

    C. F. Schleussner

    2011-09-01

    Full Text Available In order to provide probabilistic projections of the future evolution of the Atlantic Meridional Overturning Circulation (AMOC, we calibrated a simple Stommel-type box model to emulate the output of fully coupled three-dimensional atmosphere-ocean general circulation models (AOGCMs of the Coupled Model Intercomparison Project (CMIP. Based on this calibration to idealised global warming scenarios with and without interactive atmosphere-ocean fluxes and freshwater perturbation simulations, we project the future evolution of the AMOC mean strength within the covered calibration range for the lower two Representative Concentration Pathways (RCPs until 2100 obtained from the reduced complexity carbon cycle-climate model MAGICC 6. For RCP3-PD with a global mean temperature median below 1.0 °C warming relative to the year 2000, we project an ensemble median weakening of up to 11% compared to 22% under RCP4.5 with a warming median up to 1.9 °C over the 21st century. Additional Greenland meltwater of 10 and 20 cm of global sea-level rise equivalent further weakens the AMOC by about 4.5 and 10%, respectively. By combining our outcome with a multi-model sea-level rise study we project a dynamic sea-level rise along the New York City coastline of 4 cm for the RCP3-PD and of 8 cm for the RCP4.5 scenario over the 21st century. We estimate the total steric and dynamic sea-level rise for New York City to be about 24 cm until 2100 for the RCP3-PD scenario, which can hold as a lower bound for sea-level rise projections in this region, as it does not include ice sheet and mountain glacier contributions.

  19. High-speed and high-fidelity system and method for collecting network traffic

    Science.gov (United States)

    Weigle, Eric H [Los Alamos, NM

    2010-08-24

    A system is provided for the high-speed and high-fidelity collection of network traffic. The system can collect traffic at gigabit-per-second (Gbps) speeds, scale to terabit-per-second (Tbps) speeds, and support additional functions such as real-time network intrusion detection. The present system uses a dedicated operating system for traffic collection to maximize efficiency, scalability, and performance. A scalable infrastructure and apparatus for the present system is provided by splitting the work performed on one host onto multiple hosts. The present system simultaneously addresses the issues of scalability, performance, cost, and adaptability with respect to network monitoring, collection, and other network tasks. In addition to high-speed and high-fidelity network collection, the present system provides a flexible infrastructure to perform virtually any function at high speeds such as real-time network intrusion detection and wide-area network emulation for research purposes.

  20. DIMACS Workshop on Interconnection Networks and Mapping, and Scheduling Parallel Computations

    CERN Document Server

    Rosenberg, Arnold L; Sotteau, Dominique; NSF Science and Technology Center in Discrete Mathematics and Theoretical Computer Science; Interconnection networks and mapping and scheduling parallel computations

    1995-01-01

    The interconnection network is one of the most basic components of a massively parallel computer system. Such systems consist of hundreds or thousands of processors interconnected to work cooperatively on computations. One of the central problems in parallel computing is the task of mapping a collection of processes onto the processors and routing network of a parallel machine. Once this mapping is done, it is critical to schedule computations within and communication among processor from universities and laboratories, as well as practitioners involved in the design, implementation, and application of massively parallel systems. Focusing on interconnection networks of parallel architectures of today and of the near future , the book includes topics such as network topologies,network properties, message routing, network embeddings, network emulation, mappings, and efficient scheduling. inputs for a process are available where and when the process is scheduled to be computed. This book contains the refereed pro...

  1. Broken symmetries in a location-invariant word recognition network.

    Science.gov (United States)

    Hannagan, Thomas; Dandurand, Frédéric; Grainger, Jonathan

    2011-01-01

    We studied the feedforward network proposed by Dandurand et al. (2010), which maps location-specific letter inputs to location-invariant word outputs, probing the hidden layer to determine the nature of the code. Hidden patterns for words were densely distributed, and K-means clustering on single letter patterns produced evidence that the network had formed semi-location-invariant letter representations during training. The possible confound with superseding bigram representations was ruled out, and linear regressions showed that any word pattern was well approximated by a linear combination of its constituent letter patterns. Emulating this code using overlapping holographic representations (Plate, 1995) uncovered a surprisingly acute and useful correspondence with the network, stemming from a broken symmetry in the connection weight matrix and related to the group-invariance theorem (Minsky & Papert, 1969). These results also explain how the network can reproduce relative and transposition priming effects found in humans.

  2. The SICStus emulator

    OpenAIRE

    Carlsson, Mats

    1991-01-01

    This report documents internal details of Industrial SICStus Prolog, developed at the Logic Programming Laboratory of SICS. The development was funded by Ericsson Telecomm AB, NobelTech Systems AB, Infologics AB and Televerket under the IT4-program. The Implementation was done on Sun-3 and Sun-4 workstations. It has proved portable to a wide range of byte-addressed 32-bit computers running Berkeley Unix.

  3. Avaliação da estabilidade e atividade antioxidante de uma emulsão base não-iônica contendo resveratrol

    Directory of Open Access Journals (Sweden)

    Marcela Kist Lange

    2009-03-01

    Full Text Available Vários são os fatores que podem ocasionar a instabilidade de uma emulsão, destacando-se a oxidação, reação prevenida pelo emprego de antioxidantes. O butil-hidróxi-tolueno (BHT tem sido um dos antioxidantes sintéticos mais utilizados em formulações cosméticas, porém, a busca da indústria farmacêutica e cosmética pelo emprego de produtos de origem natural tem sido cada vez maior. Visto isso, o objetivo do presente trabalho foi a incorporação do resveratrol, um composto fenólico encontrado principalmente em uvas bem como em vinhos tintos, em uma emulsão base não-iônica para avaliação do perfil de estabilidade e atividade antioxidante em comparação a uma emulsão base não-iônica contendo o BHT. O perfil de estabilidade foi analisado pela observação das características organolépticas, determinação do pH e espalhabilidade, e atividade antioxidante através do teste com o radical livre 2,2-difenil-1-picrilhidrazila (DPPH. Em relação à estabilidade, a altas temperaturas, a emulsão contendo BHT mostrou-se superior à emulsão contendo resveratrol. Pela análise da atividade antioxidante, o resveratrol tanto na sua forma de extrato seco, como quando incorporado na emulsão, demonstrou significativa superioridade em relação ao BHT, podendo ser sua utilização uma alternativa viável em preparações cosméticas, devido ao seu grande potencial antioxidante.There are several factors that can lead to the instability of an emulsion, highlighting the oxidation, a reaction prevented by the use of antioxidants. The butylated hydroxytoluene (BHT has been one of the most used synthetic antioxidants in cosmetic formulations; however, pharmaceutical and cosmetic industries have shown considerable interest regarding the search for the use of natural products. Based on this, the objective of this work was the incorporation of resveratrol, a natural phenolic compound found mainly in grapes as well as in red wines, into a non

  4. Learning Networks, Networked Learning

    NARCIS (Netherlands)

    Sloep, Peter; Berlanga, Adriana

    2010-01-01

    Sloep, P. B., & Berlanga, A. J. (2011). Learning Networks, Networked Learning [Redes de Aprendizaje, Aprendizaje en Red]. Comunicar, XIX(37), 55-63. Retrieved from http://dx.doi.org/10.3916/C37-2011-02-05

  5. O papel levedura saccharomyces cerevisiae na estabilização de emulsões envolvendo hexadecano e uma fase aquosa

    OpenAIRE

    Aureliano Agostinho Dias

    2016-01-01

    Resumo: Os biocombustíveis têm sido objeto de crescente interesse nos últimos anos, uma vez que sua utilização contribui para reduzir a emissão de gases ligados ao efeito estufa. O farnesano apresenta potencial para substituir o diesel de petróleo, podendo ser obtido por processos biotecnológicos. Entretanto, durante as etapas de purificação deste composto (após a fermentação), ocorre a formação de uma emulsão relativamente estável composta por gotas de óleo, microrganismos, meio fermentativo...

  6. A network of networks.

    Science.gov (United States)

    Iedema, Rick; Verma, Raj; Wutzke, Sonia; Lyons, Nigel; McCaughan, Brian

    2017-04-10

    Purpose To further our insight into the role of networks in health system reform, the purpose of this paper is to investigate how one agency, the NSW Agency for Clinical Innovation (ACI), and the multiple networks and enabling resources that it encompasses, govern, manage and extend the potential of networks for healthcare practice improvement. Design/methodology/approach This is a case study investigation which took place over ten months through the first author's participation in network activities and discussions with the agency's staff about their main objectives, challenges and achievements, and with selected services around the state of New South Wales to understand the agency's implementation and large system transformation activities. Findings The paper demonstrates that ACI accommodates multiple networks whose oversight structures, self-organisation and systems change approaches combined in dynamic ways, effectively yield a diversity of network governances. Further, ACI bears out a paradox of "centralised decentralisation", co-locating agents of innovation with networks of implementation and evaluation expertise. This arrangement strengthens and legitimates the role of the strategic hybrid - the healthcare professional in pursuit of change and improvement, and enhances their influence and impact on the wider system. Research limitations/implications While focussing the case study on one agency only, this study is unique as it highlights inter-network connections. Contributing to the literature on network governance, this paper identifies ACI as a "network of networks" through which resources, expectations and stakeholder dynamics are dynamically and flexibly mediated and enhanced. Practical implications The co-location of and dynamic interaction among clinical networks may create synergies among networks, nurture "strategic hybrids", and enhance the impact of network activities on health system reform. Social implications Network governance requires more

  7. Intra and Inter-PON ONU to ONU Virtual Private Networking using OFDMA in a Ring Topology

    OpenAIRE

    Deng, Lei; Zhao, Ying; Pang, Xiaodan; Yu, Xianbin; Liu, Deming; Tafur Monroy, Idelfonso

    2011-01-01

    Abstract—In this paper, we propose a novel WDM-PON architecture to support efficient and bandwidth-scalable virtual private network (VPN) emulation over both inter-PON and intra- PON. The virtual ring link for the VPN communications among ONUs is realized by using additionally low-cost optical passive components and OFDMA technology. Moreover, the downstream traffic wavelength is reused for the upstream traffic signal by using re-modulation technology. We report on a successful transmission o...

  8. Co-evolutionary behaviour selection in adaptive social networks predicts clustered marginalization of minorities

    CERN Document Server

    Schleussner, Carl-Friedrich; Engemann, Denis A; Levermann, Anders

    2015-01-01

    Human behaviour is largely shaped by local social interactions and depends on the structure of connections between individuals in social networks. These two dimensions of behaviour selection are commonly studied in isolation by different disciplines and are often treated as independent processes. To the contrary, empirical findings on spread of behaviour in social networks suggest that local interactions between individuals and network evolution are interdependent. Empirical evidence, however, remains inconclusive as social network studies often suffer from limited sample sizes or are prohibitive on ethical grounds. Here we introduce a co-evolutionary adaptive network model of social behaviour selection that provides insights into generative mechanisms by resolving both these aspects through computer simulations. We considered four complementary models and evaluated them with regard to emulating empirical behaviour dynamics in social networks. For this purpose we modelled the prevalence of smoking and and the...

  9. Estabilidade de emulsões de d-limoneno em quitosana modificada Stability of d-limonene emulsions in modified chitosan

    Directory of Open Access Journals (Sweden)

    Camila Figueiredo Borgognoni

    2006-09-01

    Full Text Available A quitosana é um biopolímero produzido a partir da quitina, presente na casca de crustáceos. Atualmente, o estudo de suas propriedades se deve às suas diversas utilizações nas áreas farmacêutica e alimentícia. A quitosana utilizada neste estudo foi quimicamente modificada para tornar-se solúvel em água (quitosana succinilada. Estudou-se a estabilidade de emulsões com d-limoneno para que estes dados sejam úteis na sua posterior utilização como agente de encapsulação de d-limoneno por liofilização. Sua estabilidade foi analisada por espectrofotometria, em diferentes temperaturas, e por cromatografia gasosa associada à técnica da análise do espaço livre, à temperatura ambiente. Sua caracterização foi feita por microscopia óptica. Emulsões de maltodextrina com d-limoneno foram utilizadas para comparação já que maltodextrinas são muito usadas como agentes de encapsulação de aromas. Observou-se boa estabilidade de emulsões de quitosana succinilada com d-limoneno ao longo do tempo e características muito distintas em relação às observadas em emulsões de maltodextrina com d-limoneno. Pode-se concluir neste estudo que emulsões de quitosana succinilada com d-limoneno apresentaram características favoráveis à encapsulação de aromas.Chitosan is a biopolymer derived from chitin, a component of the shells of crustaceans. Recently, special attention has been given to the study of chitosan properties as a consequence of their wide application in pharmaceutical and food areas. In this study, the chitosan used was chemically modified in order to become water soluble (succinyl chitosan. The stability of succinyl chitosan emulsion with d-limonene was studied so that these results could be useful in a subsequent use of succinyl chitosan as a d-limonene encapsulating agent by lyophilization. The stability of the emulsion was analyzed using a spectrophotometer in different temperatures and by the headspace

  10. Subjective Evaluation of Packet Service Performance in UMTS and Heterogeneous Networks

    DEFF Research Database (Denmark)

    Teyeb, Oumer Mohammed; Sørensen, Troels Bundgaard; Mogensen, Preben

    2006-01-01

    Quality of Service (QoS) in mobile telecommunication systems is usually identified by some basic performance metrics such as delay, throughput and jitter. However, the main impact of service quality is on the end user, and as such a detailed study of service performance should involve the end user....... In this paper, such an approach is taken where subjective performance evaluation is undertaken for web browsing and video streaming services in Universal Mobile Telecommunication System (UMTS) and a heterogeneous network comprised of UMTS and Wireless LAN (WLAN). Using a real-time network emulation testbed...

  11. Real-Time Radio Wave Propagation for Mobile Ad-Hoc Network Emulation and Simulation Using General Purpose Graphics Processing Units (GPGPUs)

    Science.gov (United States)

    2014-05-01

    real-time calculations with stochastic models (3). When calculations are performed off-line it is assumed that the node mobility is known apriori . This...these capabilities with GPUs the wireless node mobility and path loss needed to either be computed apriori or use a large number of (i.e., 10,000) CPU

  12. "Mne povezlo v zhizni..." / Margarita Ostroumova ; interv. Svetlana Loginova

    Index Scriptorium Estoniae

    Ostroumova, Margarita

    2006-01-01

    Jõhvi kunstikooli endise direktori ja kunstniku Margarita Ostroumovaga tema saatusest, õpingutest, loomingust ja ühiskondlikust tööst. Margarita Ostroumova on kasvanud ja hariduse saanud Valgevenes. Ta on Valgevene kultuuriühingu esinaine, Baltimaade valgevene kunstnike ühenduse "Maju gonar" esimehe asetäitja

  13. "Mne hotshetsja vsjo uspet!" / Renata Piotrovski ; interv. Ella Agranovskaja

    Index Scriptorium Estoniae

    Piotrovski, Renata

    2006-01-01

    Moskva Kunstiteatri koolstuudio Eesti kursuse üks lõpetajatest, Renata Piotrovski oma elust Moskvas, rollist teleseriaalis "Tütarlaps Põhjamaalt". Neil päevi sõlmib Vene Teater koolstuudio lõpetajatega töölepingu

  14. Mne nravitsja vljubljatsja v talant / Renata Litvinova ; interv. Nikolai Hrustaljov

    Index Scriptorium Estoniae

    Litvinova, Renata

    2007-01-01

    Viiburis (Võborg) toimunud vene kino festivalil "Aken Euroopasse" peetud pressikonverentsil tutvustas näitleja ja režissöör oma uusimat projekti, muusikalist filmi lauljanna Zemfirast, esialgse pealkirjaga "Zeljonõi teatr v Zemfire"

  15. Sourcing Team Behavior in Project-Based MNE's

    DEFF Research Database (Denmark)

    Hansen, Anders Peder Lysholm

    2014-01-01

    This paper presents and discusses a multiple case study of three cross-functional category teams responsible for sourcing critical components within multi-national, project-based enterprises. The study focused on behaviour and management of the sourcing teams and found that the sourcing process a...

  16. Prantsusmaa president peab aastakümne kohtulahingut / Hendrik Vosman

    Index Scriptorium Estoniae

    Vosman, Hendrik

    2009-01-01

    Pariisis alanud kohtuprotsessil tehakse kindlaks, kas ekspeaminister Dominique de Villepin kavandas Nicolas Sarkozy vastu laimukampaaniat takistamaks viimase presidendiks saamist. Prantsuse vaatlejad leiavad, et protsess on eelkõige kahe poliitiku omavaheline arveteklaarimine

  17. mne aasta tõsiseim kriis / Sirje Rank

    Index Scriptorium Estoniae

    Rank, Sirje, 1966-

    2008-01-01

    Venemaa investeerimisfirma KIT Finance pankrotiohtu sattumine käivitas paanika Vene börsil. Suurfirmade juhid ootavad valitsuselt otsustavamaid samme olukorra pidurdamiseks. Vt. samas: KIT Finance; Hannes Sarv. Esimene kukkuja

  18. Carbon Nanotube Synaptic Transistor Network for Pattern Recognition.

    Science.gov (United States)

    Kim, Sungho; Yoon, Jinsu; Kim, Hee-Dong; Choi, Sung-Jin

    2015-11-18

    Inspired by the human brain, a neuromorphic system combining complementary metal-oxide semiconductor (CMOS) and adjustable synaptic devices may offer new computing paradigms by enabling massive neural-network parallelism. In particular, synaptic devices, which are capable of emulating the functions of biological synapses, are used as the essential building blocks for an information storage and processing system. However, previous synaptic devices based on two-terminal resistive devices remain challenging because of their variability and specific physical mechanisms of resistance change, which lead to a bottleneck in the implementation of a high-density synaptic device network. Here we report that a three-terminal synaptic transistor based on carbon nanotubes can provide reliable synaptic functions that encode relative timing and regulate weight change. In addition, using system-level simulations, the developed synaptic transistor network associated with CMOS circuits can perform unsupervised learning for pattern recognition using a simplified spike-timing-dependent plasticity scheme.

  19. Schedule-based sequential localization in asynchronous wireless networks

    Science.gov (United States)

    Zachariah, Dave; De Angelis, Alessio; Dwivedi, Satyam; Händel, Peter

    2014-12-01

    In this paper, we consider the schedule-based network localization concept, which does not require synchronization among nodes and does not involve communication overhead. The concept makes use of a common transmission sequence, which enables each node to perform self-localization and to localize the entire network, based on noisy propagation-time measurements. We formulate the schedule-based localization problem as an estimation problem in a Bayesian framework. This provides robustness with respect to uncertainty in such system parameters as anchor locations and timing devices. Moreover, we derive a sequential approximate maximum a posteriori (AMAP) estimator. The estimator is fully decentralized and copes with varying noise levels. By studying the fundamental constraints given by the considered measurement model, we provide a system design methodology which enables a scalable solution. Finally, we evaluate the performance of the proposed AMAP estimator by numerical simulations emulating an impulse-radio ultra-wideband (IR-UWB) wireless network.

  20. A Neuron Model for FPGA Spiking Neuronal Network Implementation

    Directory of Open Access Journals (Sweden)

    BONTEANU, G.

    2011-11-01

    Full Text Available We propose a neuron model, able to reproduce the basic elements of the neuronal dynamics, optimized for digital implementation of Spiking Neural Networks. Its architecture is structured in two major blocks, a datapath and a control unit. The datapath consists of a membrane potential circuit, which emulates the neuronal dynamics at the soma level, and a synaptic circuit used to update the synaptic weight according to the spike timing dependent plasticity (STDP mechanism. The proposed model is implemented into a Cyclone II-Altera FPGA device. Our results indicate the neuron model can be used to build up 1K Spiking Neural Networks on reconfigurable logic suport, to explore various network topologies.

  1. Enhancing Hohlraum Design with Artificial Neural Networks

    Science.gov (United States)

    Peterson, J. L.; Berzak Hopkins, L. F.; Humbird, K. D.; Brandon, S. T.; Field, J. E.; Langer, S. H.; Nora, R. C.; Spears, B. K.

    2017-10-01

    A primary goal of hohlraum design is to efficiently convert available laser power and energy to capsule drive, compression and ultimately fusion neutron yield. However, a major challenge of this multi-dimensional optimization problem is the relative computational expense of hohlraum simulations. In this work, we explore overcoming this obstacle with the use of artificial neural networks built off ensembles of hohlraum simulations. These machine learning systems emulate the behavior of full simulations in a fraction of the time, thereby enabling the rapid exploration of design parameters. We will demonstrate this technology with a search for modifications to existing high-yield designs that can maximize neutron production within NIF's current laser power and energy constraints. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-734401.

  2. Evaluation of Deployment Challenges of Wireless Sensor Networks at Signalized Intersections

    Directory of Open Access Journals (Sweden)

    Leyre Azpilicueta

    2016-07-01

    Full Text Available With the growing demand of Intelligent Transportation Systems (ITS for safer and more efficient transportation, research on and development of such vehicular communication systems have increased considerably in the last years. The use of wireless networks in vehicular environments has grown exponentially. However, it is highly important to analyze radio propagation prior to the deployment of a wireless sensor network in such complex scenarios. In this work, the radio wave characterization for ISM 2.4 GHz and 5 GHz Wireless Sensor Networks (WSNs deployed taking advantage of the existence of traffic light infrastructure has been assessed. By means of an in-house developed 3D ray launching algorithm, the impact of topology as well as urban morphology of the environment has been analyzed, emulating the realistic operation in the framework of the scenario. The complexity of the scenario, which is an intersection city area with traffic lights, vehicles, people, buildings, vegetation and urban environment, makes necessary the channel characterization with accurate models before the deployment of wireless networks. A measurement campaign has been conducted emulating the interaction of the system, in the vicinity of pedestrians as well as nearby vehicles. A real time interactive application has been developed and tested in order to visualize and monitor traffic as well as pedestrian user location and behavior. Results show that the use of deterministic tools in WSN deployment can aid in providing optimal layouts in terms of coverage, capacity and energy efficiency of the network.

  3. Evaluation of Deployment Challenges of Wireless Sensor Networks at Signalized Intersections.

    Science.gov (United States)

    Azpilicueta, Leyre; López-Iturri, Peio; Aguirre, Erik; Martínez, Carlos; Astrain, José Javier; Villadangos, Jesús; Falcone, Francisco

    2016-07-22

    With the growing demand of Intelligent Transportation Systems (ITS) for safer and more efficient transportation, research on and development of such vehicular communication systems have increased considerably in the last years. The use of wireless networks in vehicular environments has grown exponentially. However, it is highly important to analyze radio propagation prior to the deployment of a wireless sensor network in such complex scenarios. In this work, the radio wave characterization for ISM 2.4 GHz and 5 GHz Wireless Sensor Networks (WSNs) deployed taking advantage of the existence of traffic light infrastructure has been assessed. By means of an in-house developed 3D ray launching algorithm, the impact of topology as well as urban morphology of the environment has been analyzed, emulating the realistic operation in the framework of the scenario. The complexity of the scenario, which is an intersection city area with traffic lights, vehicles, people, buildings, vegetation and urban environment, makes necessary the channel characterization with accurate models before the deployment of wireless networks. A measurement campaign has been conducted emulating the interaction of the system, in the vicinity of pedestrians as well as nearby vehicles. A real time interactive application has been developed and tested in order to visualize and monitor traffic as well as pedestrian user location and behavior. Results show that the use of deterministic tools in WSN deployment can aid in providing optimal layouts in terms of coverage, capacity and energy efficiency of the network.

  4. Evaluation of Deployment Challenges of Wireless Sensor Networks at Signalized Intersections

    Science.gov (United States)

    Azpilicueta, Leyre; López-Iturri, Peio; Aguirre, Erik; Martínez, Carlos; Astrain, José Javier; Villadangos, Jesús; Falcone, Francisco

    2016-01-01

    With the growing demand of Intelligent Transportation Systems (ITS) for safer and more efficient transportation, research on and development of such vehicular communication systems have increased considerably in the last years. The use of wireless networks in vehicular environments has grown exponentially. However, it is highly important to analyze radio propagation prior to the deployment of a wireless sensor network in such complex scenarios. In this work, the radio wave characterization for ISM 2.4 GHz and 5 GHz Wireless Sensor Networks (WSNs) deployed taking advantage of the existence of traffic light infrastructure has been assessed. By means of an in-house developed 3D ray launching algorithm, the impact of topology as well as urban morphology of the environment has been analyzed, emulating the realistic operation in the framework of the scenario. The complexity of the scenario, which is an intersection city area with traffic lights, vehicles, people, buildings, vegetation and urban environment, makes necessary the channel characterization with accurate models before the deployment of wireless networks. A measurement campaign has been conducted emulating the interaction of the system, in the vicinity of pedestrians as well as nearby vehicles. A real time interactive application has been developed and tested in order to visualize and monitor traffic as well as pedestrian user location and behavior. Results show that the use of deterministic tools in WSN deployment can aid in providing optimal layouts in terms of coverage, capacity and energy efficiency of the network. PMID:27455270

  5. A Particle Swarm Optimization Algorithm for Neural Networks in Recognition of Maize Leaf Diseases

    Directory of Open Access Journals (Sweden)

    Zhiyong ZHANG

    2014-03-01

    Full Text Available The neural networks have significance on recognition of crops disease diagnosis? but it has disadvantage of slow convergent speed and shortcoming of local optimum. In order to identify the maize leaf diseases by using machine vision more accurately, we propose an improved particle swarm optimization algorithm for neural networks. With the algorithm, the neural network property is improved. It reasonably confirms threshold and connection weight of neural network, and improves capability of solving problems in the image recognition. At last, an example of the emulation shows that neural network model based on recognizes significantly better than without optimization. Model accuracy has been improved to a certain extent to meet the actual needs of maize leaf diseases recognition.

  6. Experiments on Hybrid Precast Concrete Shear Walls Emulating Monolithic Construction with Different Amounts of Posttensioned Strands and Different Debond Lengths of Grouted Reinforcements

    Directory of Open Access Journals (Sweden)

    Zhangfeng Zhu

    2016-01-01

    Full Text Available This paper proposed a hybrid precast concrete shear wall emulating monolithic construction (HPWEM that utilized grouted vertical connecting reinforcements and unbonded posttensioned high-strength strands across the horizontal joint for the lateral resistance. The grouted reinforcements with predetermined debond length were used to provide strength by tension and energy dissipation by yielding. The posttensioned strands were mainly employed to offer the restoring force to reduce the residual displacement by elastic extension. The overlapping welded closed stirrups improved the confinement property of the restrained concrete, avoiding the brittle failure. Six HPWEM specimens, considering variables including the amounts of strands and the debond lengths of grouted reinforcements, as well as one referenced cast-in-place monolithic wall specimen, were tested under the low-cycle reversed lateral load. The HPWEM specimens were capable of providing strength, stiffness, ductility, and energy dissipation equivalent to that of the monolithic wall specimen under certain variable condition.

  7. Aplicação de ferramentas estatísticas para avaliação de filmes de emulsões estireno acrílicas

    OpenAIRE

    Marcelo Beck Graziani

    2010-01-01

    Esta dissertação de Mestrado Profissional tem como objetivo a utilização de ferramentas estatísticas, tais como planejamento de experimentos (DOE) e análise de componentes principais (PCA), para a avaliação da formação de filme de emulsões estireno acrílicas (látex). A parte experimental foi realizada nos laboratórios da Dow Brasil em São Paulo. As amostras (látex + coalescente) foram caracterizadas em triplicata pelos seguintes testes: resistência à abrasão úmida, temperatura mínima de forma...

  8. Declarative Networking

    CERN Document Server

    Loo, Boon Thau

    2012-01-01

    Declarative Networking is a programming methodology that enables developers to concisely specify network protocols and services, which are directly compiled to a dataflow framework that executes the specifications. Declarative networking proposes the use of a declarative query language for specifying and implementing network protocols, and employs a dataflow framework at runtime for communication and maintenance of network state. The primary goal of declarative networking is to greatly simplify the process of specifying, implementing, deploying and evolving a network design. In addition, decla

  9. Sustainable Energy Solutions Task 1.0: Networked Monitoring and Control of Small Interconnected Wind Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    edu, Janet. twomey@wichita. [Wichita State Univ., KS (United States)

    2010-04-30

    This report presents accomplishments, results, and future work for one task of five in the Wichita State University Sustainable Energy Solutions Project: To develop a scale model laboratory distribution system for research into questions that arise from networked control and monitoring of low-wind energy systems connected to the AC distribution system. The lab models developed under this task are located in the Electric Power Quality Lab in the Engineering Research Building on the Wichita State University campus. The lab system consists of four parts: 1. A doubly-fed induction generator 2. A wind turbine emulator 3. A solar photovoltaic emulator, with battery energy storage 4. Distribution transformers, lines, and other components, and wireless and wired communications and control These lab elements will be interconnected and will function together to form a complete testbed for distributed resource monitoring and control strategies and smart grid applications testing. Development of the lab system will continue beyond this project.

  10. The optical antenna system design research on earth integrative network laser link in the future

    Science.gov (United States)

    Liu, Xianzhu; Fu, Qiang; He, Jingyi

    2014-11-01

    Earth integrated information network can be real-time acquisition, transmission and processing the spatial information with the carrier based on space platforms, such as geostationary satellites or in low-orbit satellites, stratospheric balloons or unmanned and manned aircraft, etc. It is an essential infrastructure for China to constructed earth integrated information network. Earth integrated information network can not only support the highly dynamic and the real-time transmission of broadband down to earth observation, but the reliable transmission of the ultra remote and the large delay up to the deep space exploration, as well as provide services for the significant application of the ocean voyage, emergency rescue, navigation and positioning, air transportation, aerospace measurement or control and other fields.Thus the earth integrated information network can expand the human science, culture and productive activities to the space, ocean and even deep space, so it is the global research focus. The network of the laser communication link is an important component and the mean of communication in the earth integrated information network. Optimize the structure and design the system of the optical antenna is considered one of the difficulty key technologies for the space laser communication link network. Therefore, this paper presents an optical antenna system that it can be used in space laser communication link network.The antenna system was consisted by the plurality mirrors stitched with the rotational paraboloid as a substrate. The optical system structure of the multi-mirror stitched was simulated and emulated by the light tools software. Cassegrain form to be used in a relay optical system. The structural parameters of the relay optical system was optimized and designed by the optical design software of zemax. The results of the optimal design and simulation or emulation indicated that the antenna system had a good optical performance and a certain

  11. Memristor-based neural networks: Synaptic versus neuronal stochasticity

    Directory of Open Access Journals (Sweden)

    Rawan Naous

    2016-11-01

    Full Text Available In neuromorphic circuits, stochasticity in the cortex can be mapped into the synaptic or neuronal components. The hardware emulation of these stochastic neural networks are currently being extensively studied using resistive memories or memristors. The ionic process involved in the underlying switching behavior of the memristive elements is considered as the main source of stochasticity of its operation. Building on its inherent variability, the memristor is incorporated into abstract models of stochastic neurons and synapses. Two approaches of stochastic neural networks are investigated. Aside from the size and area perspective, the impact on the system performance, in terms of accuracy, recognition rates, and learning, among these two approaches and where the memristor would fall into place are the main comparison points to be considered.

  12. Memristor-based neural networks: Synaptic versus neuronal stochasticity

    KAUST Repository

    Naous, Rawan

    2016-11-02

    In neuromorphic circuits, stochasticity in the cortex can be mapped into the synaptic or neuronal components. The hardware emulation of these stochastic neural networks are currently being extensively studied using resistive memories or memristors. The ionic process involved in the underlying switching behavior of the memristive elements is considered as the main source of stochasticity of its operation. Building on its inherent variability, the memristor is incorporated into abstract models of stochastic neurons and synapses. Two approaches of stochastic neural networks are investigated. Aside from the size and area perspective, the impact on the system performance, in terms of accuracy, recognition rates, and learning, among these two approaches and where the memristor would fall into place are the main comparison points to be considered.

  13. The network researchers' network

    DEFF Research Database (Denmark)

    Henneberg, Stephan C.; Jiang, Zhizhong; Naudé, Peter

    2009-01-01

    The Industrial Marketing and Purchasing (IMP) Group is a network of academic researchers working in the area of business-to-business marketing. The group meets every year to discuss and exchange ideas, with a conference having been held every year since 1984 (there was no meeting in 1987). In thi......The Industrial Marketing and Purchasing (IMP) Group is a network of academic researchers working in the area of business-to-business marketing. The group meets every year to discuss and exchange ideas, with a conference having been held every year since 1984 (there was no meeting in 1987......). In this paper, based upon the papers presented at the 22 conferences held to date, we undertake a Social Network Analysis in order to examine the degree of co-publishing that has taken place between this group of researchers. We identify the different components in this database, and examine the large main...

  14. Detecting community structure in networks via consensus dynamics and spatial transformation

    Science.gov (United States)

    Yang, Bo; He, He; Hu, Xiaoming

    2017-10-01

    We present a novel clustering algorithm for community detection, based on the dynamics towards consensus and spatial transformation. The community detection problem is translated to a clustering problem in the N-dimensional Euclidean space by three stages: (1) the dynamics running on a network is emulated to a procedure of gas diffusion in a finite space; (2) the pressure distribution vectors are used to describe the influence that each node exerts on the whole network; (3) the similarity measures between two nodes are quantified in the N-dimensional Euclidean space by k-Nearest Neighbors method. After such steps, we could merge clusters according to their similarity distances and show the community structure of a network by a hierarchical clustering tree. Tests on several benchmark networks are presented and the results show the effectiveness and reliability of our algorithm.

  15. Design of a stateless low-latency router architecture for green software-defined networking

    Science.gov (United States)

    Saldaña Cercós, Silvia; Ramos, Ramon M.; Ewald Eller, Ana C.; Martinello, Magnos; Ribeiro, Moisés. R. N.; Manolova Fagertun, Anna; Tafur Monroy, Idelfonso

    2015-01-01

    Expanding software defined networking (SDN) to transport networks requires new strategies to deal with the large number of flows that future core networks will have to face. New south-bound protocols within SDN have been proposed to benefit from having control plane detached from the data plane offering a cost- and energy-efficient forwarding engine. This paper presents an overview of a new approach named KeyFlow to simultaneously reduce latency, jitter, and power consumption in core network nodes. Results on an emulation platform indicate that round trip time (RTT) can be reduced above 50% compared to the reference protocol OpenFlow, specially when flow tables are densely populated. Jitter reduction has been demonstrated experimentally on a NetFPGA-based platform, and 57.3% power consumption reduction has been achieved.

  16. Network cosmology.

    Science.gov (United States)

    Krioukov, Dmitri; Kitsak, Maksim; Sinkovits, Robert S; Rideout, David; Meyer, David; Boguñá, Marián

    2012-01-01

    Prediction and control of the dynamics of complex networks is a central problem in network science. Structural and dynamical similarities of different real networks suggest that some universal laws might accurately describe the dynamics of these networks, albeit the nature and common origin of such laws remain elusive. Here we show that the causal network representing the large-scale structure of spacetime in our accelerating universe is a power-law graph with strong clustering, similar to many complex networks such as the Internet, social, or biological networks. We prove that this structural similarity is a consequence of the asymptotic equivalence between the large-scale growth dynamics of complex networks and causal networks. This equivalence suggests that unexpectedly similar laws govern the dynamics of complex networks and spacetime in the universe, with implications to network science and cosmology.

  17. Network Cosmology

    Science.gov (United States)

    Krioukov, Dmitri; Kitsak, Maksim; Sinkovits, Robert S.; Rideout, David; Meyer, David; Boguñá, Marián

    2012-01-01

    Prediction and control of the dynamics of complex networks is a central problem in network science. Structural and dynamical similarities of different real networks suggest that some universal laws might accurately describe the dynamics of these networks, albeit the nature and common origin of such laws remain elusive. Here we show that the causal network representing the large-scale structure of spacetime in our accelerating universe is a power-law graph with strong clustering, similar to many complex networks such as the Internet, social, or biological networks. We prove that this structural similarity is a consequence of the asymptotic equivalence between the large-scale growth dynamics of complex networks and causal networks. This equivalence suggests that unexpectedly similar laws govern the dynamics of complex networks and spacetime in the universe, with implications to network science and cosmology. PMID:23162688

  18. Interfacing Space Communications and Navigation Network Simulation with Distributed System Integration Laboratories (DSIL)

    Science.gov (United States)

    Jennings, Esther H.; Nguyen, Sam P.; Wang, Shin-Ywan; Woo, Simon S.

    2008-01-01

    NASA's planned Lunar missions will involve multiple NASA centers where each participating center has a specific role and specialization. In this vision, the Constellation program (CxP)'s Distributed System Integration Laboratories (DSIL) architecture consist of multiple System Integration Labs (SILs), with simulators, emulators, testlabs and control centers interacting with each other over a broadband network to perform test and verification for mission scenarios. To support the end-to-end simulation and emulation effort of NASA' exploration initiatives, different NASA centers are interconnected to participate in distributed simulations. Currently, DSIL has interconnections among the following NASA centers: Johnson Space Center (JSC), Kennedy Space Center (KSC), Marshall Space Flight Center (MSFC) and Jet Propulsion Laboratory (JPL). Through interconnections and interactions among different NASA centers, critical resources and data can be shared, while independent simulations can be performed simultaneously at different NASA locations, to effectively utilize the simulation and emulation capabilities at each center. Furthermore, the development of DSIL can maximally leverage the existing project simulation and testing plans. In this work, we describe the specific role and development activities at JPL for Space Communications and Navigation Network (SCaN) simulator using the Multi-mission Advanced Communications Hybrid Environment for Test and Evaluation (MACHETE) tool to simulate communications effects among mission assets. Using MACHETE, different space network configurations among spacecrafts and ground systems of various parameter sets can be simulated. Data that is necessary for tracking, navigation, and guidance of spacecrafts such as Crew Exploration Vehicle (CEV), Crew Launch Vehicle (CLV), and Lunar Relay Satellite (LRS) and orbit calculation data are disseminated to different NASA centers and updated periodically using the High Level Architecture (HLA). In

  19. Increased Intrinsic Connectivity of the Default Mode Network in Temporal Lobe Epilepsy: Evidence from Resting-State MEG Recordings.

    Directory of Open Access Journals (Sweden)

    Fu-Jung Hsiao

    Full Text Available The electrophysiological signature of resting state oscillatory functional connectivity within the default mode network (DMN during spike-free periods in temporal lobe epilepsy (TLE remains unclear. Using magnetoencephalographic (MEG recordings, this study investigated how the connectivity within the DMN was altered in TLE, and we examined the effect of lateralized TLE on functional connectivity. Sixteen medically intractable TLE patients and 22 controls participated in this study. Whole-scalp 306-channel MEG epochs without interictal spikes generated from both MEG and EEG data were analyzed using a minimum norm estimate (MNE and source-based imaginary coherence analysis. With this processing, we obtained the cortical activation and functional connectivity within the DMN. The functional connectivity was increased between DMN and the right medial temporal (MT region at the delta band and between DMN and the bilateral anterior cingulate cortex (ACC regions at the theta band. The functional change was associated with the lateralization of TLE. The right TLE showed enhanced DMN connectivity with the right MT while the left TLE demonstrated increased DMN connectivity with the bilateral MT. There was no lateralization effect of TLE upon the DMN connectivity with ACC. These findings suggest that the resting-state functional connectivity within the DMN is reinforced in temporal lobe epilepsy during spike-free periods. Future studies are needed to examine if the altered functional connectivity can be used as a biomarker for treatment responses, cognitive dysfunction and prognosis in patients with TLE.

  20. First trimester trophoblasts forming endothelial-like tubes in vitro emulate a 'blood vessel development' gene expression profile.

    Science.gov (United States)

    Highet, Amanda R; Buckberry, Sam; Mayne, Benjamin T; Khoda, Sultana M; Bianco-Miotto, Tina; Roberts, Claire T

    2016-07-01

    Extravillous cytotrophoblasts isolated from first trimester placenta, and immortalised cell lines derived from them, have the intrinsic ability to form endothelial-like tubes when cultured on Matrigel™ extracellular matrix. This in vitro tube formation may model placental angiogenesis and/or endovascular differentiation by trophoblasts. To interpret the relevance of this phenomenon to placental development, we used a gene expression microarray approach to identify which genes and pathways are associated with the tube-forming phenotype of HTR8/SVneo first trimester trophoblasts (HTR8-M), compared with HTR8/SVneo not forming tubes on plastic culture surface (HTR8-P). Furthermore, we used weighted gene co-expression network analysis (WGCNA) of microarray data to identify modules of co-expressed genes underlying the biological processes. There were 481 genes differentially expressed between HTR8-M and HTR8-P and these were significantly enriched for blood vessel development and related gene ontologies. WGCNA clustered the genes into 9 co-expression modules. One module was significantly associated with HTR8-M (p = 1.15E-05) and contained genes involved in actin cytoskeleton organization, cell migration and blood vessel development, consistent with tube formation on Matrigel. Another module was significantly associated with HTR8-P (p = 1.94E-05) and was enriched for genes involved in mitosis, consistent with proliferation by cells on plastic which do not differentiate. Up-regulation of angiogenesis and vascular development pathways in endovascular trophoblasts in vivo could underpin spiral artery remodelling processes, which are defective in preeclamptic pregnancies. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Telecommunication networks

    CERN Document Server

    Iannone, Eugenio

    2011-01-01

    Many argue that telecommunications network infrastructure is the most impressive and important technology ever developed. Analyzing the telecom market's constantly evolving trends, research directions, infrastructure, and vital needs, Telecommunication Networks responds with revolutionized engineering strategies to optimize network construction. Omnipresent in society, telecom networks integrate a wide range of technologies. These include quantum field theory for the study of optical amplifiers, software architectures for network control, abstract algebra required to design error correction co

  2. Bayesian model-emulation of stochastic gravitational-wave spectra for probes of the final-parsec problem with pulsar-timing arrays

    Science.gov (United States)

    Taylor, Stephen; Simon, Joseph; Sampson, Laura

    2017-01-01

    The final parsec of supermassive black-hole binary evolution is subject to the complex interplay of stellar loss-cone scattering, circumbinary disk accretion, and gravitational-wave emission, with binary eccentricity affected by all of these. The strain spectrum of gravitational-waves in the pulsar-timing band thus encodes rich information about the binary population's response to these various environmental mechanisms. Current spectral models have heretofore followed basic analytic prescriptions, and attempt to investigate these final-parsec mechanisms in an indirect fashion. Here we describe a new technique to directly probe the environmental properties of supermassive black-hole binaries through ``Bayesian model-emulation''. We perform black-hole binary population synthesis simulations at a restricted set of environmental parameter combinations, compute the strain spectra from these, then train a Gaussian process to learn the shape of spectrum at any point in parameter space. We describe this technique, demonstrate its efficacy with a program of simulated datasets, then illustrate its power by directly constraining final-parsec physics in a Bayesian analysis of the NANOGrav 5-year dataset. The technique is fast, flexible, and robust.

  3. Congestion control in satellite networks

    Science.gov (United States)

    Byun, Do Jun

    Due to exponential increases in internet traffic, Active Queue Management (AQM) has been heavily studied by numerous researchers. However, little is known about AQM in satellite networks. A microscopic examination of queueing behavior in satellite networks is conducted to identify problems with applying existing AQM methods. A new AQM method is proposed to overcome the problems and it is validated using a realistic emulation environment and a mathematical model. Three problems that were discovered during the research are discussed in this dissertation. The first problem is oscillatory queueing, which is caused by high buffering due to Performance Enhancing Proxy (PEP) in satellite networks where congestion control after the PEP buffering does not effectively control traffic senders. Existing AQMs that can solve this problem have tail drop queueing that results in consecutive packet drops (global synchronization). A new AQM method called Adaptive Virtual Queue Random Early Detection (AVQRED) is proposed to solve this problem. The second problem is unfair bandwidth sharing caused by inaccurate measurements of per-flow bandwidth usage. AVQRED is enhanced to accurately measure per-flow bandwidth usage to solve this problem without adding much complexity to the algorithm. The third problem is queueing instability caused by buffer flow control where TCP receive windows are adjusted to flow control traffic senders instead of dropping received packets during congestion. Although buffer flow control is quite attractive to satellite networks, queueing becomes unstable because accepting packets instead of dropping them aggravates the congestion level. Furthermore, buffer flow control has abrupt reductions in the TCP receive window size due to high PEP buffering causing more instability. AVQRED with packet drop is proposed to solve this problem. Networks with scarce bandwidth and high propagation delays can not afford to have an unstable AQM. In this research, three problems

  4. Book Review Emulation real estate values ​​and territorial dynamics / Reseña del libro Emulación del valor inmobiliario y dinámica territorial

    Directory of Open Access Journals (Sweden)

    Adolfo Benito Narváez Tijerina

    2011-09-01

    Full Text Available Reseña del libro: "Emulación del valor inmobiliario y dinámica territorial", de Jesús Manuel Fitch Osuna, Monterrey, Universidad Autónoma de Nuevo León-UPC, 2010. Book Review: "Emulation real estate values ​​and territorial dynamics," Jesus Manuel Fitch Osuna, Monterrey, Universidad Autonoma de Nuevo Leon-UPC, 2010.

  5. Interconnected networks

    CERN Document Server

    2016-01-01

    This volume provides an introduction to and overview of the emerging field of interconnected networks which include multi layer or multiplex networks, as well as networks of networks. Such networks present structural and dynamical features quite different from those observed in isolated networks. The presence of links between different networks or layers of a network typically alters the way such interconnected networks behave – understanding the role of interconnecting links is therefore a crucial step towards a more accurate description of real-world systems. While examples of such dissimilar properties are becoming more abundant – for example regarding diffusion, robustness and competition – the root of such differences remains to be elucidated. Each chapter in this topical collection is self-contained and can be read on its own, thus making it also suitable as reference for experienced researchers wishing to focus on a particular topic.

  6. Hybrid regression trees applied to the monitoring of dynamic safety of isolated networks with large eolic production contribution; Utilizacao de arvores de regressao hibridas na monitorizacao da seguranca dinamica de redes isoladas com grande producao eolica

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, J.A Pecas; Vasconcelos, Maria Helena O.P. de [Instituto de Engenharia de Sistemas e Computadores (INESC), Porto (Portugal). E-mail: jpl@riff.fe.up.pt; hvasconcelos@inescn.pt

    1999-07-01

    This paper describes in a synthetic manner the technology adopted to define structures used in the fast evaluation of dynamic safety of isolated network with high level of eolic production contribution. This methodology uses hybrid regression trees, which allows the quantification the endurance connected to the dynamic behavior of these networks by emulating the frequency minimum deviation that will be experienced by the system when submitted toa pre-defined perturbation. Also, new procedures for data automatic generation are presented, which will be used for construction and measurements of the evaluation structures performance. The paper describes the Terceira island - Acores archipelago network study case.

  7. Network maintenance

    CERN Multimedia

    IT Department

    2009-01-01

    A site wide network maintenance has been scheduled for Saturday 28 February. Most of the network devices of the General Purpose network will be upgraded to a newer software version, in order to improve our network monitoring capabilities. This will result in a series of short (2-5 minutes) random interruptions everywhere on the CERN sites along this day. This upgrade will not affect: the Computer centre itself, building 613, the Technical Network and the LHC experiments dedicated networks at the pits. Should you need more details on this intervention, please contact Netops by phone 74927 or email mailto:Netops@cern.ch. IT/CS Group

  8. Network maintenance

    CERN Multimedia

    GS Department

    2009-01-01

    A site-wide network maintenance operation has been scheduled for Saturday 28 February. Most of the network devices of the general purpose network will be upgraded to a newer software version, in order to improve our network monitoring capabilities. This will result in a series of short (2-5 minutes) random interruptions everywhere on the CERN sites throughout the day. This upgrade will not affect the Computer Centre itself, Building 613, the Technical Network and the LHC experiments, dedicated networks at the pits. For further details of this intervention, please contact Netops by phone 74927 or e-mail mailto:Netops@cern.ch. IT/CS Group

  9. Network Ambivalence

    Directory of Open Access Journals (Sweden)

    Patrick Jagoda

    2015-08-01

    Full Text Available The language of networks now describes everything from the Internet to the economy to terrorist organizations. In distinction to a common view of networks as a universal, originary, or necessary form that promises to explain everything from neural structures to online traffic, this essay emphasizes the contingency of the network imaginary. Network form, in its role as our current cultural dominant, makes scarcely imaginable the possibility of an alternative or an outside uninflected by networks. If so many things and relationships are figured as networks, however, then what is not a network? If a network points towards particular logics and qualities of relation in our historical present, what others might we envision in the future? In  many ways, these questions are unanswerable from within the contemporary moment. Instead of seeking an avant-garde approach (to move beyond networks or opting out of networks (in some cases, to recover elements of pre-networked existence, this essay proposes a third orientation: one of ambivalence that operates as a mode of extreme presence. I propose the concept of "network aesthetics," which can be tracked across artistic media and cultural forms, as a model, style, and pedagogy for approaching interconnection in the twenty-first century. The following essay is excerpted from Network Ambivalence (Forthcoming from University of Chicago Press. 

  10. Network neuroscience.

    Science.gov (United States)

    Bassett, Danielle S; Sporns, Olaf

    2017-02-23

    Despite substantial recent progress, our understanding of the principles and mechanisms underlying complex brain function and cognition remains incomplete. Network neuroscience proposes to tackle these enduring challenges. Approaching brain structure and function from an explicitly integrative perspective, network neuroscience pursues new ways to map, record, analyze and model the elements and interactions of neurobiological systems. Two parallel trends drive the approach: the availability of new empirical tools to create comprehensive maps and record dynamic patterns among molecules, neurons, brain areas and social systems; and the theoretical framework and computational tools of modern network science. The convergence of empirical and computational advances opens new frontiers of scientific inquiry, including network dynamics, manipulation and control of brain networks, and integration of network processes across spatiotemporal domains. We review emerging trends in network neuroscience and attempt to chart a path toward a better understanding of the brain as a multiscale networked system.

  11. Organizational Networks

    DEFF Research Database (Denmark)

    Grande, Bård; Sørensen, Ole Henning

    1998-01-01

    The paper focuses on the concept of organizational networks. Four different uses of the concept of organizational network are identified and critically discussed. Special focus is placed on how information and communication technologies as communication mediators and cognitive pictures influence...

  12. Network workshop

    DEFF Research Database (Denmark)

    Bruun, Jesper; Evans, Robert Harry

    2014-01-01

    This paper describes the background for, realisation of and author reflections on a network workshop held at ESERA2013. As a new research area in science education, networks offer a unique opportunity to visualise and find patterns and relationships in complicated social or academic network data...... research community. With this workshop, participants were offered a way into network science based on authentic educational research data. The workshop was constructed as an inquiry lesson with emphasis on user autonomy. Learning activities had participants choose to work with one of two cases of networks...... network methodology in one’s research might supersede the perceived benefits of doing so. As a response to that problem, we argue that workshops can act as a road towards meaningful engagement with networks and highlight that network methodology promises new ways of interpreting data to answer questions...

  13. Mechanistic site-based emulation of a global ocean biogeochemical model (MEDUSA 1.0 for parametric analysis and calibration: an application of the Marine Model Optimization Testbed (MarMOT 1.1

    Directory of Open Access Journals (Sweden)

    J. C. P. Hemmings

    2015-03-01

    Full Text Available Biogeochemical ocean circulation models used to investigate the role of plankton ecosystems in global change rely on adjustable parameters to capture the dominant biogeochemical dynamics of a complex biological system. In principle, optimal parameter values can be estimated by fitting models to observational data, including satellite ocean colour products such as chlorophyll that achieve good spatial and temporal coverage of the surface ocean. However, comprehensive parametric analyses require large ensemble experiments that are computationally infeasible with global 3-D simulations. Site-based simulations provide an efficient alternative but can only be used to make reliable inferences about global model performance if robust quantitative descriptions of their relationships with the corresponding 3-D simulations can be established. The feasibility of establishing such a relationship is investigated for an intermediate complexity biogeochemistry model (MEDUSA coupled with a widely used global ocean model (NEMO. A site-based mechanistic emulator is constructed for surface chlorophyll output from this target model as a function of model parameters. The emulator comprises an array of 1-D simulators and a statistical quantification of the uncertainty in their predictions. The unknown parameter-dependent biogeochemical environment, in terms of initial tracer concentrations and lateral flux information required by the simulators, is a significant source of uncertainty. It is approximated by a mean environment derived from a small ensemble of 3-D simulations representing variability of the target model behaviour over the parameter space of interest. The performance of two alternative uncertainty quantification schemes is examined: a direct method based on comparisons between simulator output and a sample of known target model "truths" and an indirect method that is only partially reliant on knowledge of the target model output. In general, chlorophyll

  14. An efficient query mechanism base on P2P networks

    Science.gov (United States)

    Wang, Xiaohua; Mu, Aiqin; Zhao, Defang

    2013-07-01

    How to implement the efficient query is the key problem deployed on P2P networks. This paper analyses the shortage of several query algorithm, and presents a new algorithm DDI, which means distributed searching with double indices. It discusses the popularity of documents and the linking status of the networks, and calculates the availability of the nodes in whole network, determines the route of the query process. It compares the items of time using, the quantity of requests and update information by the emulate experiments. Along with the rapid development of computer network technology, peer-to-peer (referred to as P2P) network research has gradually become mature, and it is widely used in different fields, some large P2P computing project has entered the implementation stage. At present, many more popular software systems such as Gnutella, Freenet, Napster are deployed based on P2P technology. How to achieve effective information query has become one of the key problems of P2P research.

  15. Social Networks

    OpenAIRE

    Martí, Joan; Zenou, Yves

    2009-01-01

    We survey the literature on social networks by putting together the economics, sociological and physics/applied mathematics approaches, showing their similarities and differences. We expose, in particular, the two main ways of modeling network formation. While the physics/applied mathematics approach is capable of reproducing most observed networks, it does not explain why they emerge. On the contrary, the economics approach is very precise in explaining why networks emerge but does a poor jo...

  16. Network Coding

    Indian Academy of Sciences (India)

    Network coding is a technique to increase the amount of information °ow in a network by mak- ing the key observation that information °ow is fundamentally different from commodity °ow. Whereas, under traditional methods of opera- tion of data networks, intermediate nodes are restricted to simply forwarding their incoming.

  17. The vulnerability of the global container shipping network to targeted link disruption

    Science.gov (United States)

    Viljoen, Nadia M.; Joubert, Johan W.

    2016-11-01

    Using complex network theory to describe the relational geography of maritime networks has provided great insights regarding their hierarchy and evolution over the past two decades. Unlike applications in other transport fields, notably air transport, complex network theory has had limited application in studying the vulnerability of maritime networks. This study uses targeted link disruption to investigate the strategy specific vulnerability of the network. Although nodal infrastructure such as ports can render a network vulnerable as a result of labour strikes, trade embargoes or natural disasters, it is the shipping lines connecting the ports that are more probably disrupted, either from within the industry, or outside. In this paper, we apply and evaluate two link-based disruption strategies on the global container shipping network, one based on link betweenness, and the other on link salience, to emulate the impact of large-scale service reconfiguration affecting priority links. The results show that the network is by and large robust to such reconfiguration. Meanwhile the flexibility of the network is reduced by both strategies, but to a greater degree by betweenness, resulting in a reduction of transshipment and dynamic rerouting potential amongst the busiest port regions. The results further show that the salience strategy is highly effective in reducing the commonality of shortest path sets, thereby diminishing opportunities for freight consolidation and scale economies.

  18. Estudo da hidratação da pele por emulsões cosméticas para xerose e sua estabilidade por reologia Study of hydration skin by the cosmetics emulsions for xerosis and their stability by rheology

    Directory of Open Access Journals (Sweden)

    Ana Lúcia Koff Milan

    2007-12-01

    Full Text Available Foram desenvolvidas as emulsões NI (não-iônica e CL (cristal líquido e avaliados os parâmetros reológicos, assim como o efeito hidratante das emulsões NI e CL em mulheres, com faixa etária de 20 ± 2 anos e da emulsão NI em mulheres com faixa etária de 70 ± 7 anos. Os resultados demonstraram adequada estabilidade das emulsões e comportamento pseudoplástico, além de tixotropia aparente. Para a emulsão NI, foi alcançado o melhor perfil reológico com menor ponto de fluidez (13,57 ± 3,19 Pa e maior espalhabilidade (4,99 ± 0,54 mm²/g. Não houve diferença significativa de hidratação dos produtos em mulheres com faixa etária de 20 ± 2 anos da emulsão NI e CL (16,0 ± 5,1%, 14,2 ± 5,5%. No entanto, a hidratação do grupo de mulheres com faixa etária de 70 ± 7 anos foi de 13,1 ± 5,6% para a emulsão NI. Esse resultado demonstra hidratação significativamente menor nesse grupo, quando comparada ao grupo com menor faixa etária. Dessa forma, foi comprovada para esse estudo a importância da avaliação reológica como fator de seleção entre formulações cosméticas semelhantes. Além disso, observou-se a relevância da seleção etária para a avaliação da hidratação cutânea de cosméticos.NI (nonionic and LC (liquid crystal emulsions were developed, and their rheological parameters were evaluated. Also, the hydrating effect of NI and LC emulsions was tested among women with 20 ± 2 years, as well as NI emulsions among women with 70 ± 7 years of age. The results showed that the emulsions were stable and they had a pseudoplastic behavior and apparent thixotropy. The data revealed the best rheological profile of the NI emulsion with the lowest pour point (13.57 ± 3.19 Pa and the highest spreadability (4.99 ± 0.54 mm²/g. There was no significant difference in hydration between NI and LC emulsions (16.0 ± 5.1%; 14.2 ± 5.5% among younger women. However, hydration among elderly women was of 13.1 ± 5.6% for NI

  19. Technical Network

    CERN Multimedia

    2007-01-01

    In order to optimise the management of the Technical Network (TN), to facilitate understanding of the purpose of devices connected to the TN and to improve security incident handling, the Technical Network Administrators and the CNIC WG have asked IT/CS to verify the "description" and "tag" fields of devices connected to the TN. Therefore, persons responsible for systems connected to the TN will receive e-mails from IT/CS asking them to add the corresponding information in the network database at "network-cern-ch". Thank you very much for your cooperation. The Technical Network Administrators & the CNIC WG

  20. Network science

    CERN Document Server

    Barabasi, Albert-Laszlo

    2016-01-01

    Networks are everywhere, from the Internet, to social networks, and the genetic networks that determine our biological existence. Illustrated throughout in full colour, this pioneering textbook, spanning a wide range of topics from physics to computer science, engineering, economics and the social sciences, introduces network science to an interdisciplinary audience. From the origins of the six degrees of separation to explaining why networks are robust to random failures, the author explores how viruses like Ebola and H1N1 spread, and why it is that our friends have more friends than we do. Using numerous real-world examples, this innovatively designed text includes clear delineation between undergraduate and graduate level material. The mathematical formulas and derivations are included within Advanced Topics sections, enabling use at a range of levels. Extensive online resources, including films and software for network analysis, make this a multifaceted companion for anyone with an interest in network sci...

  1. Vulnerability of network of networks

    Science.gov (United States)

    Havlin, S.; Kenett, D. Y.; Bashan, A.; Gao, J.; Stanley, H. E.

    2014-10-01

    Our dependence on networks - be they infrastructure, economic, social or others - leaves us prone to crises caused by the vulnerabilities of these networks. There is a great need to develop new methods to protect infrastructure networks and prevent cascade of failures (especially in cases of coupled networks). Terrorist attacks on transportation networks have traumatized modern societies. With a single blast, it has become possible to paralyze airline traffic, electric power supply, ground transportation or Internet communication. How, and at which cost can one restructure the network such that it will become more robust against malicious attacks? The gradual increase in attacks on the networks society depends on - Internet, mobile phone, transportation, air travel, banking, etc. - emphasize the need to develop new strategies to protect and defend these crucial networks of communication and infrastructure networks. One example is the threat of liquid explosives a few years ago, which completely shut down air travel for days, and has created extreme changes in regulations. Such threats and dangers warrant the need for new tools and strategies to defend critical infrastructure. In this paper we review recent advances in the theoretical understanding of the vulnerabilities of interdependent networks with and without spatial embedding, attack strategies and their affect on such networks of networks as well as recently developed strategies to optimize and repair failures caused by such attacks.

  2. Altered oscillation and synchronization of default-mode network activity in mild Alzheimer's disease compared to mild cognitive impairment: an electrophysiological study.

    Directory of Open Access Journals (Sweden)

    Fu-Jung Hsiao

    Full Text Available Some researchers have suggested that the default mode network (DMN plays an important role in the pathological mechanisms of Alzheimer's disease (AD. To examine whether the cortical activities in DMN regions show significant difference between mild AD from mild cognitive impairment (MCI, electrophysiological responses were analyzed from 21 mild Alzheimer's disease (AD and 21 mild cognitive impairment (MCI patients during an eyes closed, resting-state condition. The spectral power and functional connectivity of the DMN were estimated using a minimum norm estimate (MNE combined with fast Fourier transform and imaginary coherence analysis. Our results indicated that source-based EEG maps of resting-state activity showed alterations of cortical spectral power in mild AD when compared to MCI. These alterations are characteristic of attenuated alpha or beta activities in the DMN, as are enhanced delta or theta activities in the medial temporal, inferior parietal, posterior cingulate cortex and precuneus. With regard to altered synchronization in AD, altered functional interconnections were observed as specific connectivity patterns of connection hubs in the precuneus, posterior cingulate cortex, anterior cingulate cortex and medial temporal regions. Moreover, posterior theta and alpha power and altered connectivity in the medial temporal lobe correlated significantly with scores obtained on the Mini-Mental State Examination (MMSE. In conclusion, EEG is a useful tool for investigating the DMN in the brain and differentiating early stage AD and MCI patients. This is a promising finding; however, further large-scale studies are needed.

  3. Altered oscillation and synchronization of default-mode network activity in mild Alzheimer's disease compared to mild cognitive impairment: an electrophysiological study.

    Science.gov (United States)

    Hsiao, Fu-Jung; Wang, Yuh-Jen; Yan, Sui-Hing; Chen, Wei-Ta; Lin, Yung-Yang

    2013-01-01

    Some researchers have suggested that the default mode network (DMN) plays an important role in the pathological mechanisms of Alzheimer's disease (AD). To examine whether the cortical activities in DMN regions show significant difference between mild AD from mild cognitive impairment (MCI), electrophysiological responses were analyzed from 21 mild Alzheimer's disease (AD) and 21 mild cognitive impairment (MCI) patients during an eyes closed, resting-state condition. The spectral power and functional connectivity of the DMN were estimated using a minimum norm estimate (MNE) combined with fast Fourier transform and imaginary coherence analysis. Our results indicated that source-based EEG maps of resting-state activity showed alterations of cortical spectral power in mild AD when compared to MCI. These alterations are characteristic of attenuated alpha or beta activities in the DMN, as are enhanced delta or theta activities in the medial temporal, inferior parietal, posterior cingulate cortex and precuneus. With regard to altered synchronization in AD, altered functional interconnections were observed as specific connectivity patterns of connection hubs in the precuneus, posterior cingulate cortex, anterior cingulate cortex and medial temporal regions. Moreover, posterior theta and alpha power and altered connectivity in the medial temporal lobe correlated significantly with scores obtained on the Mini-Mental State Examination (MMSE). In conclusion, EEG is a useful tool for investigating the DMN in the brain and differentiating early stage AD and MCI patients. This is a promising finding; however, further large-scale studies are needed.

  4. Network Coded Software Defined Networking

    DEFF Research Database (Denmark)

    Hansen, Jonas; Roetter, Daniel Enrique Lucani; Krigslund, Jeppe

    2015-01-01

    . The inherent flexibility of both SDN and NC provides fertile ground to envision more efficient, robust, and secure networking designs, which may also incorporate content caching and storage, all of which are key challenges of the upcoming 5G networks. This article not only proposes the fundamentals......Software defined networking has garnered large attention due to its potential to virtualize services in the Internet, introducing flexibility in the buffering, scheduling, processing, and routing of data in network routers. SDN breaks the deadlock that has kept Internet network protocols stagnant...... for decades, while applications and physical links have evolved. This article advocates for the use of SDN to bring about 5G network services by incorporating network coding (NC) functionalities. The latter constitutes a major leap forward compared to the state-of-the- art store and forward Internet paradigm...

  5. Network Coded Software Defined Networking

    DEFF Research Database (Denmark)

    Krigslund, Jeppe; Hansen, Jonas; Roetter, Daniel Enrique Lucani

    2015-01-01

    Software Defined Networking (SDN) and Network Coding (NC) are two key concepts in networking that have garnered a large attention in recent years. On the one hand, SDN's potential to virtualize services in the Internet allows a large flexibility not only for routing data, but also to manage....... This paper advocates for the use of SDN to bring about future Internet and 5G network services by incorporating network coding (NC) functionalities. The inherent flexibility of both SDN and NC provides a fertile ground to envision more efficient, robust, and secure networking designs, that may also...... incorporate content caching and storage, all of which are key challenges of the future Internet and the upcoming 5G networks. This paper proposes some of the keys behind this intersection and supports it with use cases as well as a an implementation that integrated the Kodo library (NC) into OpenFlow (SDN...

  6. Advancing interconnect density for spiking neural network hardware implementations using traffic-aware adaptive network-on-chip routers.

    Science.gov (United States)

    Carrillo, Snaider; Harkin, Jim; McDaid, Liam; Pande, Sandeep; Cawley, Seamus; McGinley, Brian; Morgan, Fearghal

    2012-09-01

    The brain is highly efficient in how it processes information and tolerates faults. Arguably, the basic processing units are neurons and synapses that are interconnected in a complex pattern. Computer scientists and engineers aim to harness this efficiency and build artificial neural systems that can emulate the key information processing principles of the brain. However, existing approaches cannot provide the dense interconnect for the billions of neurons and synapses that are required. Recently a reconfigurable and biologically inspired paradigm based on network-on-chip (NoC) and spiking neural networks (SNNs) has been proposed as a new method of realising an efficient, robust computing platform. However, the use of the NoC as an interconnection fabric for large-scale SNNs demands a good trade-off between scalability, throughput, neuron/synapse ratio and power consumption. This paper presents a novel traffic-aware, adaptive NoC router, which forms part of a proposed embedded mixed-signal SNN architecture called EMBRACE (EMulating Biologically-inspiRed ArChitectures in hardwarE). The proposed adaptive NoC router provides the inter-neuron connectivity for EMBRACE, maintaining router communication and avoiding dropped router packets by adapting to router traffic congestion. Results are presented on throughput, power and area performance analysis of the adaptive router using a 90 nm CMOS technology which outperforms existing NoCs in this domain. The adaptive behaviour of the router is also verified on a Stratix II FPGA implementation of a 4 × 2 router array with real-time traffic congestion. The presented results demonstrate the feasibility of using the proposed adaptive NoC router within the EMBRACE architecture to realise large-scale SNNs on embedded hardware. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Geometric indicators of population persistence in branching continuous-space networks.

    Science.gov (United States)

    Sarhad, Jonathan; Manifold, Scott; Anderson, Kurt E

    2017-03-01

    We study population persistence in branching tree networks emulating systems such as river basins, cave systems, organisms on vegetation surfaces, and vascular networks. Population dynamics are modeled using a reaction-diffusion-advection equation on a metric graph which provides a continuous, spatially explicit model of network habitat. A metric graph, in contrast to a standard graph, allows for population dynamics to occur within edges rather than just at graph vertices, subsequently adding a significant level of realism. Within this framework, we stochastically generate branching tree networks with a variety of geometric features and explore the effects of network geometry on the persistence of a population which advects toward a lethal outflow boundary. We identify a metric (CM), the distance from the lethal outflow point at which half of the habitable volume of the network lies upstream of, as a promising indicator of population persistence. This metric outperforms other metrics such as the maximum and minimum distances from the lethal outflow to an upstream boundary and the total habitable volume of the network. The strength of CM as a predictor of persistence suggests that it is a proper "system length" for the branching networks we examine here that generalizes the concept of habitat length in the classical linear space models.

  8. Small Signal Loudspeaker Impedance Emulator

    DEFF Research Database (Denmark)

    Iversen, Niels Elkjær; Knott, Arnold

    2014-01-01

    Specifying the performance of audio amplifiers is typically done by playing sine waves into a pure ohmic load. However real loudspeaker impedances are not purely ohmic but characterized by the mechanical resonance between the mass of the diaphragm and the compliance of its suspension which vary...

  9. Telecommunication Networks

    DEFF Research Database (Denmark)

    Olsen, Rasmus Løvenstein; Balachandran, Kartheepan; Hald, Sara Ligaard

    2014-01-01

    In this chapter, we look into the role of telecommunication networks and their capability of supporting critical infrastructure systems and applications. The focus is on smart grids as the key driving example, bearing in mind that other such systems do exist, e.g., water management, traffic control......, etc. First, the role of basic communication is examined with a focus on critical infrastructures. We look at heterogenic networks and standards for smart grids, to give some insight into what has been done to ensure inter-operability in this direction. We then go to the physical network, and look...... at the deployment of the physical layout of the communication network and the related costs. This is an important aspect as one option to use existing networks is to deploy dedicated networks. Following this, we look at some generic models that describe reliability for accessing dynamic information. This part...

  10. Networked Identities

    DEFF Research Database (Denmark)

    Ryberg, Thomas; Larsen, Malene Charlotte

    2008-01-01

    In this article we take up a critique of the concept of Communities of Practice (CoP) voiced by several authors, who suggest that networks may provide a better metaphor to understand social forms of organisation and learning. Through a discussion of the notion of networked learning and the critique...... of CoPs we shall argue that the metaphor or theory of networked learning is itself confronted with some central tensions and challenges that need to be addressed. We then explore these theoretical and analytic challenges to the network metaphor, through an analysis of a Danish social networking site. We...... argue that understanding meaning-making and ‘networked identities’ may be relevant analytic entry points in navigating the challenges....

  11. Decentralized Consistent Network Updates in SDN with ez-Segway

    KAUST Repository

    Nguyen, Thanh Dang

    2017-03-06

    We present ez-Segway, a decentralized mechanism to consistently and quickly update the network state while preventing forwarding anomalies (loops and black-holes) and avoiding link congestion. In our design, the centralized SDN controller only pre-computes information needed by the switches during the update execution. This information is distributed to the switches, which use partial knowledge and direct message passing to efficiently realize the update. This separation of concerns has the key benefit of improving update performance as the communication and computation bottlenecks at the controller are removed. Our evaluations via network emulations and large-scale simulations demonstrate the efficiency of ez-Segway, which compared to a centralized approach, improves network update times by up to 45% and 57% at the median and the 99th percentile, respectively. A deployment of a system prototype in a real OpenFlow switch and an implementation in P4 demonstrate the feasibility and low overhead of implementing simple network update functionality within switches.

  12. Proceedings of the Neural Network Workshop for the Hanford Community

    Energy Technology Data Exchange (ETDEWEB)

    Keller, P.E.

    1994-01-01

    These proceedings were generated from a series of presentations made at the Neural Network Workshop for the Hanford Community. The abstracts and viewgraphs of each presentation are reproduced in these proceedings. This workshop was sponsored by the Computing and Information Sciences Department in the Molecular Science Research Center (MSRC) at the Pacific Northwest Laboratory (PNL). Artificial neural networks constitute a new information processing technology that is destined within the next few years, to provide the world with a vast array of new products. A major reason for this is that artificial neural networks are able to provide solutions to a wide variety of complex problems in a much simpler fashion than is possible using existing techniques. In recognition of these capabilities, many scientists and engineers are exploring the potential application of this new technology to their fields of study. An artificial neural network (ANN) can be a software simulation, an electronic circuit, optical system, or even an electro-chemical system designed to emulate some of the brain`s rudimentary structure as well as some of the learning processes that are believed to take place in the brain. For a very wide range of applications in science, engineering, and information technology, ANNs offer a complementary and potentially superior approach to that provided by conventional computing and conventional artificial intelligence. This is because, unlike conventional computers, which have to be programmed, ANNs essentially learn from experience and can be trained in a straightforward fashion to carry out tasks ranging from the simple to the highly complex.

  13. Chemical reaction network approaches to Biochemical Systems Theory.

    Science.gov (United States)

    Arceo, Carlene Perpetua P; Jose, Editha C; Marin-Sanguino, Alberto; Mendoza, Eduardo R

    2015-11-01

    This paper provides a framework to represent a Biochemical Systems Theory (BST) model (in either GMA or S-system form) as a chemical reaction network with power law kinetics. Using this representation, some basic properties and the application of recent results of Chemical Reaction Network Theory regarding steady states of such systems are shown. In particular, Injectivity Theory, including network concordance [36] and the Jacobian Determinant Criterion [43], a "Lifting Theorem" for steady states [26] and the comprehensive results of Müller and Regensburger [31] on complex balanced equilibria are discussed. A partial extension of a recent Emulation Theorem of Cardelli for mass action systems [3] is derived for a subclass of power law kinetic systems. However, it is also shown that the GMA and S-system models of human purine metabolism [10] do not display the reactant-determined kinetics assumed by Müller and Regensburger and hence only a subset of BST models can be handled with their approach. Moreover, since the reaction networks underlying many BST models are not weakly reversible, results for non-complex balanced equilibria are also needed. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Wireless Networks

    OpenAIRE

    Samaka, Mohammed; Khan, Khaled M.D.

    2007-01-01

    Wireless communication is the fastest-growing field in the telecommunication industry. Wireless networks have grown significantly as an important segment of the communications industry. They have become popular networks with the potential to provide high-speed, high-quality information exchange between two or more portable devices without any wire or conductors. Wireless networks can simply be characterized as the technology that provides seamless access to information, anywhere, anyplace, an...

  15. Enterpreneurial network

    OpenAIRE

    Thoma, Antonela; Nguyen, Lien; Kupsyte, Valdone

    2014-01-01

    Network has become more and more indispensable in the entrepreneurial world. Especially in startup businesses, network is crucial for new entrepreneurs. This project looks at how entrepreneurs in different sectors use network to become successful. We chose to work with three entrepreneurs from three companies that have been operational for a few years and conducted face to face interviews with them. Through the data from the interviews, we analyzed firstly what type of entrepreneurs they are,...

  16. Network security

    CERN Document Server

    Perez, André

    2014-01-01

    This book introduces the security mechanisms deployed in Ethernet, Wireless-Fidelity (Wi-Fi), Internet Protocol (IP) and MultiProtocol Label Switching (MPLS) networks. These mechanisms are grouped throughout the book according to the following four functions: data protection, access control, network isolation, and data monitoring. Data protection is supplied by data confidentiality and integrity control services. Access control is provided by a third-party authentication service. Network isolation is supplied by the Virtual Private Network (VPN) service. Data monitoring consists of applying

  17. Networking Japan

    DEFF Research Database (Denmark)

    Hansen, Annette Skovsted

    HIDA). Many of these alumni have and will in the future exchange ideas and keep contact not only to Japan, but also to fellow alumni around the globe and, thereby, practice south-south exchanges, which are made possible and traceable by their established alumni network and the World Network of Friends...... (WNF). Through the alumni network, Japan continues to infuse ideas to participants and alumni, who interpret and disseminate these ideas through alumni society networks and activities, but their discussions nationally and regionally also get reported back to Japan and affect future policies...

  18. Technical Network

    CERN Multimedia

    2007-01-01

    In order to optimize the management of the Technical Network (TN), to ease the understanding and purpose of devices connected to the TN, and to improve security incident handling, the Technical Network Administrators and the CNIC WG have asked IT/CS to verify the "description" and "tag" fields of devices connected to the TN. Therefore, persons responsible for systems connected to the TN will receive email notifications from IT/CS asking them to add the corresponding information in the network database. Thank you very much for your cooperation. The Technical Network Administrators & the CNIC WG

  19. Modelagem da polimerização simultânea de estireno em suspensão e emulsão Modeling styrene simultaneous suspension and emulsion polymerization systems

    Directory of Open Access Journals (Sweden)

    Marcelo K. Lenzi

    2004-06-01

    Full Text Available Apesar dos processos de polimerização em suspensão e emulsão serem processos heterogêneos, cada um origina características peculiares para a distribuição de tamanho de partículas, distribuição de pesos moleculares, taxa de nucleação das partículas de polímero, taxa de polimerização, entre outras. Neste trabalho, são realizadas polimerizações de estireno simultaneamente em suspensão e emulsão. A carga inicial do reator equivale à receita de uma polimerização em suspensão tradicional, enquanto os constituintes da emulsão são adicionados ao longo da batelada. Analisa-se como as propriedades finais do polímero e o curso da polimerização dependem do momento em que a carga característica da emulsão é adicionada à polimerização em suspensão. Apresenta-se, também, um modelo matemático para a descrição do sistema, sendo que o modelo proposto possui boa concordância com dados experimentais de conversão, pesos moleculares médios e curva de distribuição de pesos moleculares. A morfologia da partícula de polímero e os pesos moleculares médios mudam significativamente, dependendo do momento da adição da emulsão, podendo até mesmo ser obtidas curvas de distribuição de pesos moleculares bimodais. Verificou-se que as partículas apresentam características do tipo núcleo/casca, sendo o núcleo formado pelas partículas obtidas pela polimerização em suspensão e a casca formada pelas partículas do processo em emulsão.Although both emulsion and suspension polymerization processes are performed in heterogeneous media, each process presents its own typical characteristics, such as the particle size distribution, molecular weight distribution, polymer particle nucleation rates, rates of polymerization, and so on. In this work styrene polymerizations are carried out in suspension and emulsion processes simultaneously. The initial reactor charge resembles the recipe of standard styrene suspension

  20. High-Performance Integrated Control of water quality and quantity in urban water reservoirs by dynamic emulation and model predictive control

    Science.gov (United States)

    Castelletti, A.; Galelli, S.; Goedbloed, A.

    2015-12-01

    Retention basins and urban reservoirs are increasingly used to support drinking water supply in large metropolitan contexts, since they make use of a resource, i.e., stormwater, that would be otherwise wasted, thus limiting the amount of water extracted from natural systems or produced with energy-intensive techniques. Yet, the operation of these infrastructures faces a twofold challenge. First, the presence of large impervious areas in urban catchments results in high discharge peaks and runoff volumes and a fast runoff response to rainfall, with consequent very short times of concentration. Second, stormwater transports large amount of pollutants to the receiving water bodies. This paper contributes a novel High-Performance Integrated Control framework to support the real-time operation of urban water supply storages affected by water quality problems. We use a 3D hydrodynamic, high-fidelity, simulation model to predict the main water quality dynamics and inform a real-time controller based on Model Predictive Control. We integrate the simulation model into the control scheme by a model reduction process, where the high-fidelity simulator is first used to identify and then replaced by a low-order dynamic emulator, which runs orders of magnitude faster. The framework is used to design the hourly operation of Marina Reservoir, a 3.2 Mm3 stormwater-fed reservoir located in the centre of Singapore operated for drinking water supply and flood control. Because of its recent formation from a former estuary, the reservoir suffers from high salinity levels, whose dynamics is modelled with Delft3D-FLOW. Results show that the real-time operation designed by our framework drops the minimum salinity levels of nearly 30% while reducing the average annual deficit of drinking water supply by about two times the active storage of the reservoir. Such a win-win solution is obtained by means of a model reduction process that reduced the dimensionality of Delft3D-FLOW by three orders

  1. Towards a Multi-scale Montecarlo Climate Emulator for Coastal Flooding and Long-Term Coastal Change Modeling: The Beautiful Problem

    Science.gov (United States)

    Rueda, A.; Alvarez Antolinez, J. A.; Hegermiller, C.; Serafin, K.; Anderson, D. L.; Ruggiero, P.; Barnard, P.; Erikson, L. H.; Vitousek, S.; Camus, P.; Tomas, A.; Gonzalez, M.; Mendez, F. J.

    2016-02-01

    Long-term coastal evolution and coastal flooding hazards are the result of the non-linear interaction of multiple oceanographic, hydrological, geological and meteorological forcings (e.g., astronomical tide, monthly mean sea level, large-scale storm surge, dynamic wave set-up, shoreline evolution, backshore erosion). Additionally, interannual variability and trends in storminess and sea level rise are climate drivers that must be considered. Moreover, the chronology of the hydraulic boundary conditions plays an important role since a collection of consecutive minor storm events can have more impact than the 100-yr return level event. Therefore, proper modeling of shoreline erosion, beach recovery and coastal flooding should consider the sequence of storms, the multivariate nature of the hydrodynamic forcings, and the different time scales of interest (seasonality, interannual and decadal variability). To address this `beautiful problem', we propose a hybrid approach that combines: (a) numerical hydrodynamic and morphodynamic models (SWAN for wave transformation, a shoreline change model, X-Beach for modeling infragravity waves and erosion of the backshore during extreme events and RFSM-EDA (Jamieson et al, 2012) for high resolution flooding of the coastal hinterland); (b) long-term data bases (observational and hindcast) of sea state parameters, astronomical tides and non-tidal residuals; and (c) statistical downscaling techniques, non-linear data mining, and extreme value models. The statistical downscaling approaches for multivariate variables are based on circulation patterns (Espejo et al., 2014), the chronology of the circulation patterns (Guanche et al, 2013) and the event hydrographs of multivariate extremes, resulting in a time-dependent climate emulator of hydraulic boundary conditions for coupled simulations of the coastal change and flooding models. ReferencesEspejo et al (2014) Spectral ocean wave climate variability based on circulation patterns, J

  2. Emulsion of systems containing egg yolk, polysaccharides and vegetable oil Emulsão de sistemas contendo gema de ovo, polissacarídeos e óleo vegetal

    Directory of Open Access Journals (Sweden)

    Clitor Junior Fernandes de Souza

    2012-10-01

    Full Text Available This work characterizes the emulsifying properties of systems containing egg yolk (0.1; 1.0 and 2.5 % w/v and polysaccharides (xanthan gum, carrageen, pectin and carboxymethylcellulose and three different vegetable oils (sunflower, canola, and palm oils. Emulsifying activity and emulsion stability were measured of each combination and it was found the effect of the oil on emulsion stability correlated to the amount of monounsaturated fatty acid. Additionally, increased egg yolk concentration increased emulsifying activity by reducing coalescence of oil droplets. Lastly, 2.5% egg yolk and 0.2% polysaccharide generated emulsions with high emulsifying activity, excellent stability, and droplet size of 4.32 µm.Neste trabalho, caracterizam-se as propriedades emulsificantes de sistemas contendo gema de ovo (0,1; 1,0 e 2,5% m/v, polissacarídeos (goma xantana, carragena, pectina e carboximetilcelulose e três diferentes óleos vegetais (óleos de palma, canola e girassol. Atividade emulsificante e estabilidade da emulsão foram medidas para cada combinação e verificou-se o efeito do óleo sobre a estabilidade da emulsão correlacionada com a quantidade de ácido graxo monoinsaturado. Além disso, a concentração de gema de ovo aumentou a atividade emulsificante, reduzindo a coalescência das gotículas de óleo. Por último, 2,5 % de gema de ovo e 0,2% de polissacarídeo formaram emulsões com alta atividade emulsificante, excelente estabilidade e tamanho de gota de 4,32 µm.

  3. Overlay networks toward information networking

    CERN Document Server

    Tarkoma, Sasu

    2010-01-01

    With their ability to solve problems in massive information distribution and processing, while keeping scaling costs low, overlay systems represent a rapidly growing area of R&D with important implications for the evolution of Internet architecture. Inspired by the author's articles on content based routing, Overlay Networks: Toward Information Networking provides a complete introduction to overlay networks. Examining what they are and what kind of structures they require, the text covers the key structures, protocols, and algorithms used in overlay networks. It reviews the current state of th

  4. Heterodox networks

    DEFF Research Database (Denmark)

    Lala, Purnima; Kumar, Ambuj

    2016-01-01

    It is imperative for the service providers to bring innovation in the network design to meet the exponential growth of mobile subscribers for multi-technology future wireless networks. As a matter of research, studies on providing services to moving subscriber groups aka ‘Place Time Capacity (PTC...

  5. Sensor networks

    NARCIS (Netherlands)

    Chatterjea, Supriyo; Thurston, J.; Kininmonth, S.; Havinga, Paul J.M.

    2006-01-01

    This article describes the details of a sensor network that is currently being deployed at the Great Barrier Reef in Australia. The sensor network allows scientists to retrieve sensor data that has a high spatial and temporal resolution. We give an overview of the energy-efficient data aggregation

  6. Network Protocols

    NARCIS (Netherlands)

    Tanenbaum, A.S.

    1981-01-01

    Dunng the last ten years, many computer networks have been designed, implemented, and put into service in the United States, Canada, Europe, Japan, and elsewhere. From the experience obtamed with these networks, certain key design principles have begun to emerge, principles that can be used to

  7. Probabilistic Networks

    DEFF Research Database (Denmark)

    Jensen, Finn Verner; Lauritzen, Steffen Lilholt

    2001-01-01

    This article describes the basic ideas and algorithms behind specification and inference in probabilistic networks based on directed acyclic graphs, undirected graphs, and chain graphs.......This article describes the basic ideas and algorithms behind specification and inference in probabilistic networks based on directed acyclic graphs, undirected graphs, and chain graphs....

  8. Organizational Networks

    DEFF Research Database (Denmark)

    Sørensen, Ole Henning; Grande, Bård

    1996-01-01

    The paper focuses on the concept of organizational networks. Four different uses of the concept are identified and critically discussed.......The paper focuses on the concept of organizational networks. Four different uses of the concept are identified and critically discussed....

  9. Affective Networks

    OpenAIRE

    Jodi Dean

    2010-01-01

    This article sets out the idea of affective networks as a constitutive feature of communicative capitalism. It explores the circulation of intensities in contemporary information and communication networks, arguing that this circulation should be theorized in terms of the psychoanalytic notion of the drive. The article includes critical engagements with theorists such as Guy Debord, Jacques Lacan, Tiziana Terranova, and Slavoj Zizek.

  10. Network chemistry, network toxicology, network informatics, and network behavioristics: A scientific outline

    OpenAIRE

    WenJun Zhang

    2016-01-01

    In present study, I proposed some new sciences: network chemistry, network toxicology, network informatics, and network behavioristics. The aims, scope and scientific foundation of these sciences are outlined.

  11. Network Affordances

    DEFF Research Database (Denmark)

    Samson, Audrey; Soon, Winnie

    2015-01-01

    This paper examines the notion of network affordance within the context of network art. Building on Gibson's theory (Gibson, 1979) we understand affordance as the perceived and actual parameters of a thing. We expand on Gaver's affordance of predictability (Gaver, 1996) to include ecological...... and computational parameters of unpredictability. We illustrate the notion of unpredictability by considering four specific works that were included in a network art exhibiton, SPEED SHOW [2.0] Hong Kong. The paper discusses how the artworks are contingent upon the parameteric relations (Parisi, 2013......), of the network. We introduce network affordance as a dynamic framework that could articulate the experienced tension arising from the (visible) symbolic representation of computational processes and its hidden occurrences. We base our proposal on the experience of both organising the SPEED SHOW and participating...

  12. A miniature protein stabilized by a cation-π interaction network core

    Science.gov (United States)

    Craven, Timothy W.; Cho, Min-Kyu; Traaseth, Nathaniel J.; Bonneau, Richard; Kirshenbaum, Kent

    2016-01-01

    The design of folded miniature proteins is predicated on establishing non-covalent interactions that direct the self-assembly of discrete thermo-stable tertiary structures. In this work, we describe how a network of cation-π interactions present in proteins containing “WSXWS motifs” can be emulated to stabilize the core of a miniature protein. This 19-residue protein sequence recapitulates a set of interdigitated arginine and tryptophan residues that stabilize a distinctive β-strand:loop:PPII-helix topology. Validation of the compact fold determined by NMR was carried out by mutagenesis of the cation-π network and by comparison to the corresponding disulfide-bridged structure. These results support the involvement of a coordinated set of cation-π interactions that stabilize the tertiary structure. PMID:26812069

  13. Training a multilayer neural network for the Euro-dollar (EUR/ USD exchange rate

    Directory of Open Access Journals (Sweden)

    Jaime Alberto Villamil Torres

    2010-04-01

    Full Text Available A mathematical tool or model for predicting how an economic variable like the exchange rate (relative price between two currencies will respond is a very important need for investors and policy-makers. Most current techniques are based on statistics, particularly linear time series theory. Artificial neural networks (ANNs are mathematical models which try to emulate biological neural networks’ parallelism and nonlinearity; these models have been successfully applied in Economics and Engineering since the 1980s. ANNs appear to be an alternative for modelling the behaviour of financial variables which resemble (as first approximation a random walk. This paper reports the results of using ANNs for Euro/USD exchange rate trading and the usefulness of the algorithm for chemotaxis leading to training networks thereby maximising an objective function re predicting a trader’s profits. JEL: F310, C450.

  14. Control Strategy Based on Wavelet Transform and Neural Network for Hybrid Power System

    Directory of Open Access Journals (Sweden)

    Y. D. Song

    2013-01-01

    Full Text Available This paper deals with an energy management of a hybrid power generation system. The proposed control strategy for the energy management is based on the combination of wavelet transform and neural network arithmetic. The hybrid system in this paper consists of an emulated wind turbine generator, PV panels, DC and AC loads, lithium ion battery, and super capacitor, which are all connected on a DC bus with unified DC voltage. The control strategy is responsible for compensating the difference between the generated power from the wind and solar generators and the demanded power by the loads. Wavelet transform decomposes the power difference into smoothed component and fast fluctuated component. In consideration of battery protection, the neural network is introduced to calculate the reference power of battery. Super capacitor (SC is controlled to regulate the DC bus voltage. The model of the hybrid system is developed in detail under Matlab/Simulink software environment.

  15. System identification and adaptive control theory and applications of the neurofuzzy and fuzzy cognitive network models

    CERN Document Server

    Boutalis, Yiannis; Kottas, Theodore; Christodoulou, Manolis A

    2014-01-01

    Presenting current trends in the development and applications of intelligent systems in engineering, this monograph focuses on recent research results in system identification and control. The recurrent neurofuzzy and the fuzzy cognitive network (FCN) models are presented.  Both models are suitable for partially-known or unknown complex time-varying systems. Neurofuzzy Adaptive Control contains rigorous proofs of its statements which result in concrete conclusions for the selection of the design parameters of the algorithms presented. The neurofuzzy model combines concepts from fuzzy systems and recurrent high-order neural networks to produce powerful system approximations that are used for adaptive control. The FCN model  stems  from fuzzy cognitive maps and uses the notion of “concepts” and their causal relationships to capture the behavior of complex systems. The book shows how, with the benefit of proper training algorithms, these models are potent system emulators suitable for use in engineering s...

  16. The Study of Indoor and Field Trials on 2×8 MIMO Architecture in TD-LTE Network

    Directory of Open Access Journals (Sweden)

    Xiang Zhang

    2013-01-01

    the networks are based on frequency division duplexing (FDD. In this paper, measurement methods of four MIMO transmission modes (TMs in time division-LTE (TD-LTE are studied and analyzed. Link level simulation is carried out to evaluate the downlink throughput for different signal-to-noise ratios and parameter settings. Furthermore, indoor and field tests are also presented in the paper to investigate how real-world propagation affects the capacity and the error performance of MIMO transmission scheme. For the indoor test, radio channel emulators are applied to generate realistic wireless fading channel, while in the field trials, a live TD-LTE experiment cellular network is built, which contains several evolved nodeBs (eNBs and a precommercial user equipment (UE. It is shown from both simulation and tests results that MIMO deployment gives a substantial performance improvement compared with the third generation wireless networks.

  17. Social networks

    CERN Document Server

    Etaner-Uyar, A Sima

    2014-01-01

    The present volume provides a comprehensive resource for practitioners and researchers alike-both those new to the field as well as those who already have some experience. The work covers Social Network Analysis theory and methods with a focus on current applications and case studies applied in various domains such as mobile networks, security, machine learning and health. With the increasing popularity of Web 2.0, social media has become a widely used communication platform. Parallel to this development, Social Network Analysis gained in importance as a research field, while opening up many

  18. Network Warrior

    CERN Document Server

    Donahue, Gary

    2011-01-01

    Pick up where certification exams leave off. With this practical, in-depth guide to the entire network infrastructure, you'll learn how to deal with real Cisco networks, rather than the hypothetical situations presented on exams like the CCNA. Network Warrior takes you step by step through the world of routers, switches, firewalls, and other technologies based on the author's extensive field experience. You'll find new content for MPLS, IPv6, VoIP, and wireless in this completely revised second edition, along with examples of Cisco Nexus 5000 and 7000 switches throughout. Topics include: An

  19. Determinação do fator de proteção solar (FPS in vitro e in vivo de emulsões com óleo de andiroba (Carapa guianensis

    Directory of Open Access Journals (Sweden)

    Márcio Ferrari

    Full Text Available O óleo de andiroba extraído da Carapa guianensis tem apresentado considerável interesse pelas indústrias farmacêutica e cosmética devido a suas propriedades antiinflamatória e repelente de insetos. Esta pesquisa teve como objetivo avaliar a atividade fotoprotetora in vitro e in vivo do óleo de andiroba. Emulsões estáveis do tipo O/A foram preparadas com o metoxicinamato de etilhexila aditivadas ou não com óleo de andiroba. As características organolépticas foram avaliadas através de análises macroscópicas e o tipo de emulsão pelo teste de diluição. O FPS in vitro foi determinado pelo método espectrofotométrico desenvolvido por Mansur, e o teste in vivo de acordo com a metodologia padronizada pela Food and Drug Administration (FDA. Não houve diferença estatística entre as formulações, demonstrando que o óleo de andiroba não apresentou atividade fotoprotetora.

  20. Quantitative analysis of digital outcrop data obtained from stereo-imagery using an emulator for the PanCam camera system for the ExoMars 2020 rover

    Science.gov (United States)

    Barnes, Robert; Gupta, Sanjeev; Gunn, Matt; Paar, Gerhard; Balme, Matt; Huber, Ben; Bauer, Arnold; Furya, Komyo; Caballo-Perucha, Maria del Pilar; Traxler, Chris; Hesina, Gerd; Ortner, Thomas; Banham, Steven; Harris, Jennifer; Muller, Jan-Peter; Tao, Yu

    2017-04-01

    A key focus of planetary rover missions is to use panoramic camera systems to image outcrops along rover traverses, in order to characterise their geology in search of ancient life. This data can be processed to create 3D point clouds of rock outcrops to be quantitatively analysed. The Mars Utah Rover Field Investigation (MURFI 2016) is a Mars Rover field analogue mission run by the UK Space Agency (UKSA) in collaboration with the Canadian Space Agency (CSA). It took place between 22nd October and 13th November 2016 and consisted of a science team based in Harwell, UK, and a field team including an instrumented Rover platform at the field site near Hanksville (Utah, USA). The Aberystwyth University PanCam Emulator 3 (AUPE3) camera system was used to collect stereo panoramas of the terrain the rover encountered during the field trials. Stereo-imagery processed in PRoViP is rendered as Ordered Point Clouds (OPCs) in PRo3D, enabling the user to zoom, rotate and translate the 3D outcrop model. Interpretations can be digitised directly onto the 3D surface, and simple measurements can be taken of the dimensions of the outcrop and sedimentary features, including grain size. Dip and strike of bedding planes, stratigraphic and sedimentological boundaries and fractures is calculated within PRo3D from mapped bedding contacts and fracture traces. Merging of rover-derived imagery with UAV and orbital datasets, to build semi-regional multi-resolution 3D models of the area of operations for immersive analysis and contextual understanding. In-simulation, AUPE3 was mounted onto the rover mast, collecting 16 stereo panoramas over 9 'sols'. 5 out-of-simulation datasets were collected in the Hanksville-Burpee Quarry. Stereo panoramas were processed using an automated pipeline and data transfer through an ftp server. PRo3D has been used for visualisation and analysis of this stereo data. Features of interest in the area could be annotated, and their distances between to the rover

  1. Uso do óleo de pequi (Caryocar brasiliense) em emulsões cosméticas: desenvolvimento e avaliação da estabilidade física Use of pequi oil (Caryocar brasiliense) in cosmetics emulsions: development and evaluate of physical stability

    OpenAIRE

    Aline Rocha Pianovski; Adrea Fernanda Gonçalves Vilela; Alex Antonio Serafim da Silva; Cleide Garbelini Lima; Ketlyn Konageski da Silva; Vanessa Franco Marcelo Carvalho; Carlo Ralph de Musis; Silvia Regina Pengo Machado; Márcio Ferrari

    2008-01-01

    Os objetivos deste trabalho foram desenvolver e avaliar a estabilidade física de emulsões O/A contendo óleo de pequi (Caryocar brasiliense). Emulsões O/A contendo 10,0% (p/p) de óleo de pequi foram preparadas e, para promover a estabilidade, a adição de carbomer, magnesium sulfate, sodium chloride e sorbitan oleate, foram estudadas. O tipo de emulsão foi verificado pelo método de diluição e o aspecto, homogeneidade e características organolépticas avaliadas através de análises macroscópicas. ...

  2. Managing Networks

    DEFF Research Database (Denmark)

    Jørgensen, Heidi; Vintergaard, Christian

    Logically it seems that companies pursuing different business strategies wouldalso manage their relationships with other firms accordingly. Nevertheless, due tothe lack of research in the field of network strategies, this link still remainsinadequately examined. Based on the well-known framework...... isprovided, that the relation between a company's strategy, structure and processesin fact have a considerable influence on its pattern of network behaviour. Threecase studies from the Danish biotech industry exemplify and illustrate how acompany's strategy is directly correlated with how it manages its...... of organisationalbehaviour developed by Miles and Snow (1978), this paper argues that thepatterns of network behaviour practiced by firms greatly depend on the businesstypology of the company. That is, a company's business typology will to a certaindegree dictate the network identity of the company. In this paper evidence...

  3. Heterodox networks

    DEFF Research Database (Denmark)

    Lala, Purnima; Kumar, Ambuj

    2016-01-01

    architecture of ‘Hovering Ad-hoc Network (HANET)’ for the latter will be deployed to assist and manage the overloaded primary base stations enhancing the on-demand coverage and capacity of the entire system. Proposed modes can either operate independently or as a cascaded architecture to form a Heterodox......It is imperative for the service providers to bring innovation in the network design to meet the exponential growth of mobile subscribers for multi-technology future wireless networks. As a matter of research, studies on providing services to moving subscriber groups aka ‘Place Time Capacity (PTC......)’ have not been considered much in the literature. In this article we present Heterodox networks as an innovative and alternate approach to handle the PTC congestion. We describe two different approaches to combat the PTC congestion where the traditional terrestrial infrastructure fails to provide...

  4. Exchange Network

    Science.gov (United States)

    The Environmental Information Exchange Network (EIEN) is an Internet-based system used by state, tribal and territorial partners to securely share environmental and health information with one another and EPA.

  5. Sentinel Network

    Science.gov (United States)

    The Sentinel Network is an integrated, electronic, national medical product safety initiative that compiles information about the safe and effective use of medical products accessible to patients and healthcare practitioners.

  6. computer networks

    Directory of Open Access Journals (Sweden)

    N. U. Ahmed

    2002-01-01

    Full Text Available In this paper, we construct a new dynamic model for the Token Bucket (TB algorithm used in computer networks and use systems approach for its analysis. This model is then augmented by adding a dynamic model for a multiplexor at an access node where the TB exercises a policing function. In the model, traffic policing, multiplexing and network utilization are formally defined. Based on the model, we study such issues as (quality of service QoS, traffic sizing and network dimensioning. Also we propose an algorithm using feedback control to improve QoS and network utilization. Applying MPEG video traces as the input traffic to the model, we verify the usefulness and effectiveness of our model.

  7. DVB-S2 Experiment over NASA's Space Network

    Science.gov (United States)

    Downey, Joseph A.; Evans, Michael A.; Tollis, Nicholas S.

    2017-01-01

    The commercial DVB-S2 standard was successfully demonstrated over NASAs Space Network (SN) and the Tracking Data and Relay Satellite System (TDRSS) during testing conducted September 20-22nd, 2016. This test was a joint effort between NASA Glenn Research Center (GRC) and Goddard Space Flight Center (GSFC) to evaluate the performance of DVB-S2 as an alternative to traditional NASA SN waveforms. Two distinct sets of tests were conducted: one was sourced from the Space Communication and Navigation (SCaN) Testbed, an external payload on the International Space Station, and the other was sourced from GRCs S-band ground station to emulate a Space Network user through TDRSS. In both cases, a commercial off-the-shelf (COTS) receiver made by Newtec was used to receive the signal at White Sands Complex. Using SCaN Testbed, peak data rates of 5.7 Mbps were demonstrated. Peak data rates of 33 Mbps were demonstrated over the GRC S-band ground station through a 10MHz channel over TDRSS, using 32-amplitude phase shift keying (APSK) and a rate 89 low density parity check (LDPC) code. Advanced features of the DVB-S2 standard were evaluated, including variable and adaptive coding and modulation (VCMACM), as well as an adaptive digital pre-distortion (DPD) algorithm. These features provided additional data throughput and increased link performance reliability. This testing has shown that commercial standards are a viable, low-cost alternative for future Space Network users.

  8. Affective Networks

    Directory of Open Access Journals (Sweden)

    Jodi Dean

    2010-02-01

    Full Text Available This article sets out the idea of affective networks as a constitutive feature of communicative capitalism. It explores the circulation of intensities in contemporary information and communication networks, arguing that this circulation should be theorized in terms of the psychoanalytic notion of the drive. The article includes critical engagements with theorists such as Guy Debord, Jacques Lacan, Tiziana Terranova, and Slavoj Zizek.

  9. Friendship Networks

    OpenAIRE

    Jan K. Brueckner

    2004-01-01

    Building upon a long tradition in sociology, economists have recently turned their attention to the analysis of social networks. The present paper adds to this emerging literature by proposing a different approach to social-network formation. As in the model of Jackson and Wolinsky (1996), formation of a link between two individuals requires two-sided investments in the present framework. But in contrast to their approach, where the required investments are exogenously specified and link form...

  10. Developer Network

    Energy Technology Data Exchange (ETDEWEB)

    2012-08-21

    NREL's Developer Network, developer.nrel.gov, provides data that users can access to provide data to their own analyses, mobile and web applications. Developers can retrieve the data through a Web services API (application programming interface). The Developer Network handles overhead of serving up web services such as key management, authentication, analytics, reporting, documentation standards, and throttling in a common architecture, while allowing web services and APIs to be maintained and managed independently.

  11. Network Power Fault Detection

    OpenAIRE

    Siviero, Claudio

    2013-01-01

    Network power fault detection. At least one first network device is instructed to temporarily disconnect from a power supply path of a network, and at least one characteristic of the power supply path of the network is measured at a second network device connected to the network while the at least one first network device is temporarily disconnected from the network

  12. Complex Networks

    CERN Document Server

    Evsukoff, Alexandre; González, Marta

    2013-01-01

    In the last decade we have seen the emergence of a new inter-disciplinary field focusing on the understanding of networks which are dynamic, large, open, and have a structure sometimes called random-biased. The field of Complex Networks is helping us better understand many complex phenomena such as the spread of  deseases, protein interactions, social relationships, to name but a few. Studies in Complex Networks are gaining attention due to some major scientific breakthroughs proposed by network scientists helping us understand and model interactions contained in large datasets. In fact, if we could point to one event leading to the widespread use of complex network analysis is the availability of online databases. Theories of Random Graphs from Erdös and Rényi from the late 1950s led us to believe that most networks had random characteristics. The work on large online datasets told us otherwise. Starting with the work of Barabási and Albert as well as Watts and Strogatz in the late 1990s, we now know th...

  13. Effect of Heterogeneity on Decorrelation Mechanisms in Spiking Neural Networks: A Neuromorphic-Hardware Study

    Directory of Open Access Journals (Sweden)

    Thomas Pfeil

    2016-05-01

    Full Text Available High-level brain function, such as memory, classification, or reasoning, can be realized by means of recurrent networks of simplified model neurons. Analog neuromorphic hardware constitutes a fast and energy-efficient substrate for the implementation of such neural computing architectures in technical applications and neuroscientific research. The functional performance of neural networks is often critically dependent on the level of correlations in the neural activity. In finite networks, correlations are typically inevitable due to shared presynaptic input. Recent theoretical studies have shown that inhibitory feedback, abundant in biological neural networks, can actively suppress these shared-input correlations and thereby enable neurons to fire nearly independently. For networks of spiking neurons, the decorrelating effect of inhibitory feedback has so far been explicitly demonstrated only for homogeneous networks of neurons with linear subthreshold dynamics. Theory, however, suggests that the effect is a general phenomenon, present in any system with sufficient inhibitory feedback, irrespective of the details of the network structure or the neuronal and synaptic properties. Here, we investigate the effect of network heterogeneity on correlations in sparse, random networks of inhibitory neurons with nonlinear, conductance-based synapses. Emulations of these networks on the analog neuromorphic-hardware system Spikey allow us to test the efficiency of decorrelation by inhibitory feedback in the presence of hardware-specific heterogeneities. The configurability of the hardware substrate enables us to modulate the extent of heterogeneity in a systematic manner. We selectively study the effects of shared input and recurrent connections on correlations in membrane potentials and spike trains. Our results confirm that shared-input correlations are actively suppressed by inhibitory feedback also in highly heterogeneous networks exhibiting broad

  14. A Flexible Experimental Laboratory for Distributed Generation Networks Based on Power Inverters

    Directory of Open Access Journals (Sweden)

    Jaume Miret

    2017-10-01

    Full Text Available In the recently deregulated electricity market, distributed generation based on renewable sources is becoming more and more relevant. In this area, two main distributed scenarios are focusing the attention of recent research: grid-connected mode, where the generation sources are connected to a grid mainly supplied by big power plants, and islanded mode, where the distributed sources, energy storage devices, and loads compose an autonomous entity that in its general form can be named a microgrid. To conduct a successful research in these two scenarios, it is essential to have a flexible experimental setup. This work deals with the description of a real laboratory setup composed of four nodes that can emulate both scenarios of a distributed generation network. A comprehensive description of the hardware and software setup will be done, focusing especially in the dual-core DSP used for control purposes, which is next to the industry standards and able to emulate real complexities. A complete experimental section will show the main features of the system.

  15. Coexisting Behaviors of Asymmetric Attractors in Hyperbolic-Type Memristor based Hopfield Neural Network

    Directory of Open Access Journals (Sweden)

    Bocheng Bao

    2017-08-01

    Full Text Available A new hyperbolic-type memristor emulator is presented and its frequency-dependent pinched hysteresis loops are analyzed by numerical simulations and confirmed by hardware experiments. Based on the emulator, a novel hyperbolic-type memristor based 3-neuron Hopfield neural network (HNN is proposed, which is achieved through substituting one coupling-connection weight with a memristive synaptic weight. It is numerically shown that the memristive HNN has a dynamical transition from chaotic, to periodic, and further to stable point behaviors with the variations of the memristor inner parameter, implying the stabilization effect of the hyperbolic-type memristor on the chaotic HNN. Of particular interest, it should be highly stressed that for different memristor inner parameters, different coexisting behaviors of asymmetric attractors are emerged under different initial conditions, leading to the existence of multistable oscillation states in the memristive HNN. Furthermore, by using commercial discrete components, a nonlinear circuit is designed and PSPICE circuit simulations and hardware experiments are performed. The results simulated and captured from the realization circuit are consistent with numerical simulations, which well verify the facticity of coexisting asymmetric attractors' behaviors.

  16. 802.11s based multi-radio multi-channel mesh networking for fractionated spacecraft

    Science.gov (United States)

    Michel, Tony; Thapa, Bishal; Taylor, Steve

    802.11s is a new IEEE standard for mesh networking. It defines the protocols needed to build mobile ad hoc networks that operate over 802.11a, b, g and n waveforms running on inexpensive, and high performance commercial WiFi stations. We have developed a new capability to add to the 802.11s that uses multiple directional radio links that can operate simultaneously within a single mesh node. This is the basis of our multi-channel multi-radio mesh network used in the DARPA F6 program called F6Net. We have developed an analysis and emulation facility that lets us model the F6Net and evaluate the performance in a real world experimentation setup. This paper presents an “ Over-the-Air” experimentation testbed that uses standard Commercial Off-The-Shelf (COTS) 2.4GHz WiFi dongles in an indoor environment, and a shared-code simulation testbed that uses hardware simulated drivers within NS3's channel simulation facility to test 80211s network. To the best of our knowledge, this is the first work that provides a comprehensive evaluation platform with a full-fledged COTS hardware/software prototype to evaluate 802.11s network. Furthermore, we explain the design and development of multi-radio mesh extension for 802.11s that yields a robust and scalable mesh network suitable for clusters of LEO satellites.

  17. Probabilistic Inference in General Graphical Models through Sampling in Stochastic Networks of Spiking Neurons

    Science.gov (United States)

    Pecevski, Dejan; Buesing, Lars; Maass, Wolfgang

    2011-01-01

    An important open problem of computational neuroscience is the generic organization of computations in networks of neurons in the brain. We show here through rigorous theoretical analysis that inherent stochastic features of spiking neurons, in combination with simple nonlinear computational operations in specific network motifs and dendritic arbors, enable networks of spiking neurons to carry out probabilistic inference through sampling in general graphical models. In particular, it enables them to carry out probabilistic inference in Bayesian networks with converging arrows (“explaining away”) and with undirected loops, that occur in many real-world tasks. Ubiquitous stochastic features of networks of spiking neurons, such as trial-to-trial variability and spontaneous activity, are necessary ingredients of the underlying computational organization. We demonstrate through computer simulations that this approach can be scaled up to neural emulations of probabilistic inference in fairly large graphical models, yielding some of the most complex computations that have been carried out so far in networks of spiking neurons. PMID:22219717

  18. Probabilistic inference in general graphical models through sampling in stochastic networks of spiking neurons.

    Directory of Open Access Journals (Sweden)

    Dejan Pecevski

    2011-12-01

    Full Text Available An important open problem of computational neuroscience is the generic organization of computations in networks of neurons in the brain. We show here through rigorous theoretical analysis that inherent stochastic features of spiking neurons, in combination with simple nonlinear computational operations in specific network motifs and dendritic arbors, enable networks of spiking neurons to carry out probabilistic inference through sampling in general graphical models. In particular, it enables them to carry out probabilistic inference in Bayesian networks with converging arrows ("explaining away" and with undirected loops, that occur in many real-world tasks. Ubiquitous stochastic features of networks of spiking neurons, such as trial-to-trial variability and spontaneous activity, are necessary ingredients of the underlying computational organization. We demonstrate through computer simulations that this approach can be scaled up to neural emulations of probabilistic inference in fairly large graphical models, yielding some of the most complex computations that have been carried out so far in networks of spiking neurons.

  19. Desenvolvimento e estudos de estabilidade preliminares de emulsões O/A contendo Cetoconazol 2,0% = Development and Preliminary Stability Evaluations of O/W emulsion containing Ketoconazole 2.0%

    Directory of Open Access Journals (Sweden)

    Vanessa Catalá Casteli

    2008-07-01

    Full Text Available O objetivo deste trabalho foi desenvolver emulsões O/A contendo Cetoconazol 2,0% e avaliar sua estabilidade preliminar por meio da análise de suas características físicoquímicas, tais como homogeneidade, formação de agregados, floculação, cremeação ecoalescência. As emulsões foram formuladas utilizando diferentes bases autoemulsionantes, compostas por álcool cetoestearílico, álcool etoxilado, álcool graxos superiores, ácido esteárico, lanolina e outros. As emulsões foram submetidas aos testes de centrifugação,estresse térmico e ciclo gela-degela, e suas características organolépticas e físico-químicas foram avaliadas no início e no final de cada ensaio. Todas as amostras mantiveram sua homogeneidade após o teste de centrifugação, mas somente os sistemas preparados comceras autoemulsionáveis constituídas por álcool graxos superiores (Polawax NF® e Copolímero de Amônio Acriloil dimetiltaurato VP, Trilauril 4 fosfato, Sesquisosterato de metil glicose, Óleo de flores de verão e Tetradibutil pentaeritritil hidroxihidrocinamato deGlicerina (Hostacerin NCB® mantiveram sua estabilidade após testes de estresse térmico e ciclo gela-degela.The objective of this work was the development of O/W emulsions containing Ketoconazole 2.0% and to evaluate their preliminary stability by analyzing physical-chemical characteristics such as homogeneity, aggregation formation, flocculation, creaming and coalescence. The emulsions were formulated using different self-emulsifying bases, composed of cetearyl alcohol, ethoxylalcohol, higher fatty alcohol, stearic acid, lanolin and others. The O/W emulsions were evaluated by centrifugation test, thermal stress test, and freezing/defrosting cycles, and its organoleptic and physical-chemistry characteristics were analyzed before and after eachassay. All samples maintained their homogeneity after the centrifugation test, but only the systems prepared with self emulsifying composed of

  20. Indução anestésica com nanoemulsão ou emulsão lipídica de propofol durante dias consecutivos em gatas

    Directory of Open Access Journals (Sweden)

    Gabriela Oliveira Gall

    2013-11-01

    Full Text Available O objetivo deste estudo foi comparar os efeitos clínicos da indução com propofol em nanoemulsão e em emulsão lipídica em gatas, após repetidas administrações. Utilizaram-se 12 gatas, hígidas, SRD, com peso médio de 2,9±0,6kg, distribuídas aleatoriamente em dois grupos: NANO (n=6 e EMU (n=6, que receberam propofol em nanoemulsão na dose de 9,5mg kg-1 e em emulsão lipídica na dose de 10mg kg-1, respectivamente, ambos pela via intravenosa, durante cinco dias consecutivos. Hemograma e função renal e hepática foram realizados a cada 24 horas e até 168 horas após a primeira indução. Os parâmetros clínicos de frequência cardíaca (FC e respiratória (f e temperatura retal (TR foram avaliados antes dos tratamentos e 5, 10, 20 e 30 minutos após a administração de propofol. Em relação aos valores basais, observou-se diminuição da FC no EMU até o 3° dia e da f e TR em ambos os grupos até o último dia, sem diferença entre os dias. As enzimas ALT e FA diminuíram após 24 a 96 horas e 48 a 144 horas, respectivamente, no grupo EMU. Os valores de eritrograma diminuíram até o quinto dia em ambos os grupos. Os tempos para hipnose, extubação e para decúbito esternal não diferiram entre grupos e entre os dias. O tempo para recuperação total do grupo EMU foi maior no 4° e 5° dias em relação ao 1°. Conclui-se que a indução com propofol é segura e que o propofol em emulsão lipídica apresenta maior efeito cumulativo após repetidas administrações em gatas.

  1. Network interruptions

    CERN Document Server

    2005-01-01

    On Sunday 12 June 2005, a site-wide security software upgrade will be performed on all CERN network equipment. This maintenance operation will cause at least 2 short network interruptions of 2 minutes on each equipment item. There are hundreds of such items across the CERN site (Meyrin, Prévessin and all SPS and LHC pits), and it will thus take the whole day to treat them all. All network users and services will be affected. Central batch computing services will be interrupted during this period, expected to last from 8 a.m. until late evening. Job submission will still be possible but no jobs will actually be run. It is hoped to complete the computer centre upgrades in the morning so that stable access can be restored to lxplus, afs and nice services as soon as possible; this cannot be guaranteed, however. The opportunity will be used to interrupt and perform upgrades on the CERN Document Servers.

  2. Network Survivability

    DEFF Research Database (Denmark)

    Marzo, José L.; Stidsen, Thomas Riis; Ruepp, Sarah Renée

    2010-01-01

    – are vital to modern services such as mobile telephony, online banking and VoIP. This book examines communication networking from a mathematical viewpoint. The contributing authors took part in the European COST action 293 – a four-year program of multidisciplinary research on this subject. In this book...... they offer introductory overviews and state-of-the-art assessments of current and future research in the fields of broadband, optical, wireless and ad hoc networks. Particular topics of interest are design, optimization, robustness and energy consumption. The book will be of interest to graduate students......, researchers and practitioners in the areas of networking, theoretical computer science, operations research, distributed computing and mathematics....

  3. Nuclear networking.

    Science.gov (United States)

    Xie, Wei; Burke, Brian

    2017-07-04

    Nuclear lamins are intermediate filament proteins that represent important structural components of metazoan nuclear envelopes (NEs). By combining proteomics and superresolution microscopy, we recently reported that both A- and B-type nuclear lamins form spatially distinct filament networks at the nuclear periphery of mouse fibroblasts. In particular, A-type lamins exhibit differential association with nuclear pore complexes (NPCs). Our studies reveal that the nuclear lamina network in mammalian somatic cells is less ordered and more complex than that of amphibian oocytes, the only other system in which the lamina has been visualized at high resolution. In addition, the NPC component Tpr likely links NPCs to the A-type lamin network, an association that appears to be regulated by C-terminal modification of various A-type lamin isoforms. Many questions remain, however, concerning the structure and assembly of lamin filaments, as well as with their mode of association with other nuclear components such as peripheral chromatin.

  4. Influence of the formulation type (o/w, w/o/w emulsions and ointment on the topical delivery of paromomycin Influência da forma farmacêutica (emulsão múltipla A/O/A, emulsão O/A e pomada sobre a permeação e retenção cutânea da paromomicina

    Directory of Open Access Journals (Sweden)

    Sérgio Fernandes de Oliveira Gomes

    2004-09-01

    Full Text Available Ointments containing paromomycin (PA have been used for topical treatment of cutaneous leishmaniasis. Although influence of the vehicle on skin permeation is crucial for optimization of formulations containing PA, this aspect has not been investigated experimentally. In this study, we have evaluated the influence of the formulation type [oil-in-water (o/w, water-in-oil-in-water (w/o/w emulsions and ointment] on in vitro release and skin permeation of PA and experiments were carried out on cellulose acetate membrane and skin biopsies from hairless mice, respectively. PA release from o/w emulsion (51.7% ± 0.9 of dose applied was faster than that observed for w/o/w emulsion (3.0% ± 0.5. PA absorption from o/w emulsion (87.1% ± 3.9 through stripped skin was 5 to 6 times higher than that observed for w/o/w multiple emulsion (14.7% ± 0.5 and ointment (16.6% ± 0.1. PA permeation through intact (normal skin was negligible for all tested formulations. Skin uptake from o/w emulsion (0.9% ± 0.1 was greater than that observed for w/o/w multiple emulsion (0.3% ± 0.1 and ointment (0.1% ± 0.1. These results suggest that a hydrophilic vehicle (o/w emulsion could be an interesting alternative to improve topical delivery of PA.Pomadas contendo paromomicina (PA são utilizadas no tratamento tópico da leishmaniose cutânea. Embora a influência do veículo seja crucial para otimização de formulações contendo PA, este aspecto não tem sido investigado experimentalmente. Neste estudo, nós avaliamos a influência do tipo de formulação [emulsões óleo-em-água (o/a, múltipla água-em-óleo-em-água (a/o/a e pomadas] sobre a liberação e permeação cutânea in vitro da PA e os experimentos foram conduzidos sobre membranas de acetato de celulose e biópsias de pele de camundongos glabros, respectivamente. A liberação de PA a partir da emulsão o/a (51,7% da dose aplicada foi mais rápida do que aquela observada a partir da emulsão múltipla a

  5. Industrial Networks

    DEFF Research Database (Denmark)

    Karlsson, Christer

    2015-01-01

    the focus of operations management from managing the own organization to continuously developing and managing a network of external and internal resources forming a production system. This perspective may be called managing an “extraprise” rather than an “enterprise.” It should be noted that “an industrial...... network” should not be seen as an organizational form but as a perspective that can be used to enrich one's understanding of organizations. The industrial network perspective has three basic building blocks: actors, resources, and activities. The three building blocks and their relations constitute...

  6. Simulation of Attacks for Security in Wireless Sensor Network.

    Science.gov (United States)

    Diaz, Alvaro; Sanchez, Pablo

    2016-11-18

    The increasing complexity and low-power constraints of current Wireless Sensor Networks (WSN) require efficient methodologies for network simulation and embedded software performance analysis of nodes. In addition, security is also a very important feature that has to be addressed in most WSNs, since they may work with sensitive data and operate in hostile unattended environments. In this paper, a methodology for security analysis of Wireless Sensor Networks is presented. The methodology allows designing attack-aware embedded software/firmware or attack countermeasures to provide security in WSNs. The proposed methodology includes attacker modeling and attack simulation with performance analysis (node's software execution time and power consumption estimation). After an analysis of different WSN attack types, an attacker model is proposed. This model defines three different types of attackers that can emulate most WSN attacks. In addition, this paper presents a virtual platform that is able to model the node hardware, embedded software and basic wireless channel features. This virtual simulation analyzes the embedded software behavior and node power consumption while it takes into account the network deployment and topology. Additionally, this simulator integrates the previously mentioned attacker model. Thus, the impact of attacks on power consumption and software behavior/execution-time can be analyzed. This provides developers with essential information about the effects that one or multiple attacks could have on the network, helping them to develop more secure WSN systems. This WSN attack simulator is an essential element of the attack-aware embedded software development methodology that is also introduced in this work.

  7. Apparatus and method for modifying the operation of a robotic vehicle in a real environment, to emulate the operation of the robotic vehicle operating in a mixed reality environment

    Science.gov (United States)

    Garretson, Justin R [Albuquerque, NM; Parker, Eric P [Albuquerque, NM; Gladwell, T Scott [Albuquerque, NM; Rigdon, J Brian [Edgewood, NM; Oppel, III, Fred J.

    2012-05-29

    Apparatus and methods for modifying the operation of a robotic vehicle in a real environment to emulate the operation of the robotic vehicle in a mixed reality environment include a vehicle sensing system having a communications module attached to the robotic vehicle for communicating operating parameters related to the robotic vehicle in a real environment to a simulation controller for simulating the operation of the robotic vehicle in a mixed (live, virtual and constructive) environment wherein the affects of virtual and constructive entities on the operation of the robotic vehicle (and vice versa) are simulated. These effects are communicated to the vehicle sensing system which generates a modified control command for the robotic vehicle including the effects of virtual and constructive entities, causing the robot in the real environment to behave as if virtual and constructive entities existed in the real environment.

  8. Photo-induced valence change of the sulfur atom in an L-cysteine thin film grown on a silver metal substrate in a saliva-emulated aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Tsujibayashi, Toru [Department of Physics, Osaka Dental University, 8-1 Kuzuha-hanazono, Hirakata, Osaka 573-1121 (Japan); Azuma, Junpei; Yamamoto, Isamu; Takahashi, Kazutoshi; Kamada, Masao [Synchrotron Light Application Center, Saga University, 1 Honjo, Saga, Saga 840-8502 (Japan)

    2015-04-27

    A thin film of L-cysteine (HSCH{sub 2}CH(NH{sub 2})COOH) is grown on a silver substrate in saliva-emulated aqueous solution. X-ray photoemission spectroscopic measurements have revealed that the sulfur atom shows valence change under IR laser irradiation at 825 nm. The valence change maintains for about a minute at room temperature and more than an hour between 110 and 250 K after stopping the laser irradiation. It is not observed at all at temperatures lower than 110 K. This temperature-dependent behavior indicates that the photo-excited electronic change should be accompanied by a conformational change in the L-cysteine molecule. It is strongly suggested that the reversible valence change of the sulfur atom is applicable to a memory used around room temperature.

  9. Nepal Networking

    DEFF Research Database (Denmark)

    Hansen, Annette Skovsted

    that their personal networks engage not only their families, but also their home communities and by extension Nepal. The two women constitute weak links between their country and other countries and as such they function as bridges or channels for transmission of practices, ideas, knowledge, and artefacts. However...

  10. Network Society

    DEFF Research Database (Denmark)

    Clausen, Lars; Tække, Jesper

    2018-01-01

    the five strands of theory on the network society. Each theoretical position has its specific implications for acting toward strategic goals. In its entirety, the five perspectives give a thorough understanding of the conditions for successful strategic communication in the 21st century....

  11. Network Coding

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 7. Network Coding. K V Rashmi Nihar B Shah P Vijay Kumar. General Article Volume 15 Issue 7 July 2010 pp 604-621. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/015/07/0604-0621. Keywords.

  12. Network Society

    DEFF Research Database (Denmark)

    Clausen, Lars; Tække, Jesper

    2017-01-01

    the five strands of theory on the network society. Each theoretical position has its specific implications for acting toward strategic goals. In its entirety, the five perspectives give a thorough understanding of the conditions for successful strategic communication in the 21st century....

  13. distribution network

    African Journals Online (AJOL)

    user

    This paper examined the acidic properties of distribution transformer oil insulation in service at Jericho distribution network Ibadan, Nigeria. Five oil samples each from six distribution transformers (DT1, DT2, DT3, DT4 and DT5) making a total of thirty samples were taken from different installed distribution transformers all ...

  14. LEA: An Algorithm to Estimate the Level of Location Exposure in Infrastructure-Based Wireless Networks

    Directory of Open Access Journals (Sweden)

    Francisco Garcia

    2017-01-01

    Full Text Available Location privacy in wireless networks is nowadays a major concern. This is due to the fact that the mere fact of transmitting may allow a network to pinpoint a mobile node. We consider that a first step to protect a mobile node in this situation is to provide it with the means to quantify how accurately a network establishes its position. To achieve this end, we introduce the location-exposure algorithm (LEA, which runs on the mobile terminal only and whose operation consists of two steps. In the first step, LEA discovers the positions of nearby network nodes and uses this information to emulate how they estimate the position of the mobile node. In the second step, it quantifies the level of exposure by computing the distance between the position estimated in the first step and its true position. We refer to these steps as a location-exposure problem. We tested our proposal with simulations and testbed experiments. These results show the ability of LEA to reproduce the location of the mobile node, as seen by the network, and to quantify the level of exposure. This knowledge can help the mobile user decide which actions should be performed before transmitting.

  15. A Passive Testing Approach for Protocols in Wireless Sensor Networks.

    Science.gov (United States)

    Che, Xiaoping; Maag, Stephane; Tan, Hwee-Xian; Tan, Hwee-Pink; Zhou, Zhangbing

    2015-11-19

    Smart systems are today increasingly developed with the number of wireless sensor devices drastically increasing. They are implemented within several contexts throughout our environment. Thus, sensed data transported in ubiquitous systems are important, and the way to carry them must be efficient and reliable. For that purpose, several routing protocols have been proposed for wireless sensor networks (WSN). However, one stage that is often neglected before their deployment is the conformance testing process, a crucial and challenging step. Compared to active testing techniques commonly used in wired networks, passive approaches are more suitable to the WSN environment. While some works propose to specify the protocol with state models or to analyze them with simulators and emulators, we here propose a logic-based approach for formally specifying some functional requirements of a novel WSN routing protocol. We provide an algorithm to evaluate these properties on collected protocol execution traces. Further, we demonstrate the efficiency and suitability of our approach by its application into common WSN functional properties, as well as specific ones designed from our own routing protocol. We provide relevant testing verdicts through a real indoor testbed and the implementation of our protocol. Furthermore, the flexibility, genericity and practicability of our approach have been proven by the experimental results.

  16. Network Performance and Quality of Experience of Remote Access Laboratories

    Directory of Open Access Journals (Sweden)

    Alexander A. Kist

    2012-11-01

    Full Text Available Remote Access Laboratories (RAL have become important learning and teaching tools. This paper presents a performance study that targets a specific remote access architecture implemented within a universities operational environment. This particular RAL system provides globally authenticated and arbitrated remote access to virtualized computers as well as computer controlled hardware experiments. This paper presents system performance results that have been obtained utilizing both a set of automated and human subject tests. Principle objectives of the study were: To gain a better understanding of the nature of network traffic caused by experimental activity usage; to obtain an indication of user expectations of activity performance; and to develop a measure to predict Quality of Experience, based on easily measurable Quality of Service parameters. The study emulates network layer variation of access-bandwidth and round-trip-time of typical usage scenarios and contrasts against user perception results that allow classifying expected user performance. It demonstrates that failure rate is excellent measure of usability, and that round-trip-time predominantly affects user experience. Thin-client and remote desktop architectures are popular to separate the location of users and the actual data processing and use similar structures, hence results of this study to be applied in these application areas as well.

  17. Adaptive Gain Scheduled Semiactive Vibration Control Using a Neural Network

    Directory of Open Access Journals (Sweden)

    Kazuhiko Hiramoto

    2018-01-01

    Full Text Available We propose an adaptive gain scheduled semiactive control method using an artificial neural network for structural systems subject to earthquake disturbance. In order to design a semiactive control system with high control performance against earthquakes with different time and/or frequency properties, multiple semiactive control laws with high performance for each of multiple earthquake disturbances are scheduled with an adaptive manner. Each semiactive control law to be scheduled is designed based on the output emulation approach that has been proposed by the authors. As the adaptive gain scheduling mechanism, we introduce an artificial neural network (ANN. Input signals of the ANN are the measured earthquake disturbance itself, for example, the acceleration, velocity, and displacement. The output of the ANN is the parameter for the scheduling of multiple semiactive control laws each of which has been optimized for a single disturbance. Parameters such as weight and bias in the ANN are optimized by the genetic algorithm (GA. The proposed design method is applied to semiactive control design of a base-isolated building with a semiactive damper. With simulation study, the proposed adaptive gain scheduling method realizes control performance exceeding single semiactive control optimizing the average of the control performance subject to various earthquake disturbances.

  18. A Passive Testing Approach for Protocols in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Xiaoping Che

    2015-11-01

    Full Text Available Smart systems are today increasingly developed with the number of wireless sensor devices drastically increasing. They are implemented within several contexts throughout our environment. Thus, sensed data transported in ubiquitous systems are important, and the way to carry them must be efficient and reliable. For that purpose, several routing protocols have been proposed for wireless sensor networks (WSN. However, one stage that is often neglected before their deployment is the conformance testing process, a crucial and challenging step. Compared to active testing techniques commonly used in wired networks, passive approaches are more suitable to the WSN environment. While some works propose to specify the protocol with state models or to analyze them with simulators and emulators, we here propose a logic-based approach for formally specifying some functional requirements of a novel WSN routing protocol. We provide an algorithm to evaluate these properties on collected protocol execution traces. Further, we demonstrate the efficiency and suitability of our approach by its application into common WSN functional properties, as well as specific ones designed from our own routing protocol. We provide relevant testing verdicts through a real indoor testbed and the implementation of our protocol. Furthermore, the flexibility, genericity and practicability of our approach have been proven by the experimental results.

  19. Social Networks and Network Structures

    Science.gov (United States)

    2006-11-01

    Research in Command & Control • Latent Semantic Analysis – Team communication – Emergent team dynamics – Shared situation awareness • Dynamic Network...requirements – Information technology requirements 28 LSA Essentials of Latent Semantic Analysis 29 Communication Analysis • Goal: Automatically monitor and

  20. Introduction to neural networks

    CERN Document Server

    James, Frederick E

    1994-02-02

    1. Introduction and overview of Artificial Neural Networks. 2,3. The Feed-forward Network as an inverse Problem, and results on the computational complexity of network training. 4.Physics applications of neural networks.

  1. Network gravity

    Science.gov (United States)

    Lombard, John

    2017-01-01

    We introduce the construction of a new framework for probing discrete emergent geometry and boundary-boundary observables based on a fundamentally a-dimensional underlying network structure. Using a gravitationally motivated action with Forman weighted combinatorial curvatures and simplicial volumes relying on a decomposition of an abstract simplicial complex into realized embeddings of proper skeletons, we demonstrate properties such as a minimal volume-scale cutoff, the necessity of a term playing the role of a positive definite cosmological constant as a regulator for nondegenerate geometries, and naturally emergent simplicial structures from Metropolis network evolution simulations with no restrictions on attachment rules or regular building blocks. We see emergent properties which echo results from both the spinfoam formalism and causal dynamical triangulations in quantum gravity, and provide analytical and numerical results to support the analogy. We conclude with a summary of open questions and intent for future work in developing the program.

  2. Neural Networks

    Directory of Open Access Journals (Sweden)

    Schwindling Jerome

    2010-04-01

    Full Text Available This course presents an overview of the concepts of the neural networks and their aplication in the framework of High energy physics analyses. After a brief introduction on the concept of neural networks, the concept is explained in the frame of neuro-biology, introducing the concept of multi-layer perceptron, learning and their use as data classifer. The concept is then presented in a second part using in more details the mathematical approach focussing on typical use cases faced in particle physics. Finally, the last part presents the best way to use such statistical tools in view of event classifers, putting the emphasis on the setup of the multi-layer perceptron. The full article (15 p. corresponding to this lecture is written in french and is provided in the proceedings of the book SOS 2008.

  3. Network Frontier Workshop 2013

    Science.gov (United States)

    2014-11-11

    networks, biological networks, cognitive and semantic networks and social networks. This field has received a major boost caused by the availability of huge...networks, which require new ways of thinking about the world. Part of the new cognition is provided by the fractional calculus description of temporal...structures in a wide range of examples—including road networks in large urban areas, a rabbit warren, a dolphin social network, a European interbank network

  4. Linear network theory

    CERN Document Server

    Sander, K F

    1964-01-01

    Linear Network Theory covers the significant algebraic aspect of network theory, with minimal reference to practical circuits. The book begins the presentation of network analysis with the exposition of networks containing resistances only, and follows it up with a discussion of networks involving inductance and capacity by way of the differential equations. Classification and description of certain networks, equivalent networks, filter circuits, and network functions are also covered. Electrical engineers, technicians, electronics engineers, electricians, and students learning the intricacies

  5. Surface Networks

    OpenAIRE

    Kostrikov, Ilya; Bruna, Joan; Panozzo, Daniele; Zorin, Denis

    2017-01-01

    We study data-driven representations for three-dimensional triangle meshes, which are one of the prevalent objects used to represent 3D geometry. Recent works have developed models that exploit the intrinsic geometry of manifolds and graphs, namely the Graph Neural Networks (GNNs) and its spectral variants, which learn from the local metric tensor via the Laplacian operator. Despite offering excellent sample complexity and built-in invariances, intrinsic geometry alone is invariant to isometr...

  6. Loss Networks

    OpenAIRE

    Kelly, F. P.

    1991-01-01

    This paper describes work on the stochastic modelling of loss networks. Such systems have long been of interest to telephone engineers and are becoming increasingly important as models of computer and information systems. Throughout the century problems from this field have provided an impetus to the development of probability theory, pure and applied. This paper provides an introduction to the area and a review of recent work.

  7. Modeling the citation network by network cosmology.

    Science.gov (United States)

    Xie, Zheng; Ouyang, Zhenzheng; Zhang, Pengyuan; Yi, Dongyun; Kong, Dexing

    2015-01-01

    Citation between papers can be treated as a causal relationship. In addition, some citation networks have a number of similarities to the causal networks in network cosmology, e.g., the similar in-and out-degree distributions. Hence, it is possible to model the citation network using network cosmology. The casual network models built on homogenous spacetimes have some restrictions when describing some phenomena in citation networks, e.g., the hot papers receive more citations than other simultaneously published papers. We propose an inhomogenous causal network model to model the citation network, the connection mechanism of which well expresses some features of citation. The node growth trend and degree distributions of the generated networks also fit those of some citation networks well.

  8. Modeling the citation network by network cosmology.

    Directory of Open Access Journals (Sweden)

    Zheng Xie

    Full Text Available Citation between papers can be treated as a causal relationship. In addition, some citation networks have a number of similarities to the causal networks in network cosmology, e.g., the similar in-and out-degree distributions. Hence, it is possible to model the citation network using network cosmology. The casual network models built on homogenous spacetimes have some restrictions when describing some phenomena in citation networks, e.g., the hot papers receive more citations than other simultaneously published papers. We propose an inhomogenous causal network model to model the citation network, the connection mechanism of which well expresses some features of citation. The node growth trend and degree distributions of the generated networks also fit those of some citation networks well.

  9. Risky Behaviors and Social Networking Sites: How Is YouTube Influencing Our Youth?

    Science.gov (United States)

    Ahern, Nancy R; Sauer, Penny; Thacker, Paige

    2015-10-01

    Choking, cutting, and setting oneself on fire are just a few of the risky behaviors that the YouTube video sharing website has allowed youth around the world to view, emulate, and comment on. Some researchers contend that the viewing of videos may normalize these behaviors for youth. Disturbing current trends are explored to illustrate the darker side of YouTube. Psychiatric-mental health nurses (PMHNs) are in key positions to help parents and youth better understand the benefits and risks of social networking sites, including YouTube, and to encourage healthy and safe use of the Internet. Nursing implications are offered for PMHNs, educators, health care providers, and parents who have contact with this population. Copyright 2015, SLACK Incorporated.

  10. Using Weightless Neural Networks for Vergence Control in an Artificial Vision System

    Directory of Open Access Journals (Sweden)

    Karin S. Komati

    2003-01-01

    Full Text Available This paper presents a methodology we have developed and used to implement an artificial binocular vision system capable of emulating the vergence of eye movements. This methodology involves using weightless neural networks (WNNs as building blocks of artificial vision systems. Using the proposed methodology, we have designed several architectures of WNN-based artificial vision systems, in which images captured by virtual cameras are used for controlling the position of the ‘foveae’ of these cameras (high-resolution region of the images captured. Our best architecture is able to control the foveae vergence movements with average error of only 3.58 image pixels, which is equivalent to an angular error of approximately 0.629°.

  11. Short-term load forecasting using neural network for future smart grid application

    Science.gov (United States)

    Zennamo, Joseph Anthony, III

    Short-term load forecasting of power system has been a classic problem for a long time. Not merely it has been researched extensively and intensively, but also a variety of forecasting methods has been raised. This thesis outlines some aspects and functions of smart meter. It also presents different policies and current statuses as well as future projects and objectives of SG development in several countries. Then the thesis compares main aspects about latest products of smart meter from different companies. Lastly, three types of prediction models are established in MATLAB to emulate the functions of smart grid in the short-term load forecasting, and then their results are compared and analyzed in terms of accuracy. For this thesis, more variables such as dew point temperature are used in the Neural Network model to achieve more accuracy for better short-term load forecasting results.

  12. Growing adaptive machines combining development and learning in artificial neural networks

    CERN Document Server

    Bredeche, Nicolas; Doursat, René

    2014-01-01

    The pursuit of artificial intelligence has been a highly active domain of research for decades, yielding exciting scientific insights and productive new technologies. In terms of generating intelligence, however, this pursuit has yielded only limited success. This book explores the hypothesis that adaptive growth is a means of moving forward. By emulating the biological process of development, we can incorporate desirable characteristics of natural neural systems into engineered designs, and thus move closer towards the creation of brain-like systems. The particular focus is on how to design artificial neural networks for engineering tasks. The book consists of contributions from 18 researchers, ranging from detailed reviews of recent domains by senior scientists, to exciting new contributions representing the state of the art in machine learning research. The book begins with broad overviews of artificial neurogenesis and bio-inspired machine learning, suitable both as an introduction to the domains and as a...

  13. Biofabricated soft network composites for cartilage tissue engineering.

    Science.gov (United States)

    Bas, Onur; De-Juan-Pardo, Elena M; Meinert, Christoph; D'Angella, Davide; Baldwin, Jeremy G; Bray, Laura J; Wellard, R Mark; Kollmannsberger, Stefan; Rank, Ernst; Werner, Carsten; Klein, Travis J; Catelas, Isabelle; Hutmacher, Dietmar W

    2017-05-12

    Articular cartilage from a material science point of view is a soft network composite that plays a critical role in load-bearing joints during dynamic loading. Its composite structure, consisting of a collagen fiber network and a hydrated proteoglycan matrix, gives rise to the complex mechanical properties of the tissue including viscoelasticity and stress relaxation. Melt electrospinning writing allows the design and fabrication of medical grade polycaprolactone (mPCL) fibrous networks for the reinforcement of soft hydrogel matrices for cartilage tissue engineering. However, these fiber-reinforced constructs underperformed under dynamic and prolonged loading conditions, suggesting that more targeted design approaches and material selection are required to fully exploit the potential of fibers as reinforcing agents for cartilage tissue engineering. In the present study, we emulated the proteoglycan matrix of articular cartilage by using highly negatively charged star-shaped poly(ethylene glycol)/heparin hydrogel (sPEG/Hep) as the soft matrix. These soft hydrogels combined with mPCL melt electrospun fibrous networks exhibited mechanical anisotropy, nonlinearity, viscoelasticity and morphology analogous to those of their native counterpart, and provided a suitable microenvironment for in vitro human chondrocyte culture and neocartilage formation. In addition, a numerical model using the p-version of the finite element method (p-FEM) was developed in order to gain further insights into the deformation mechanisms of the constructs in silico, as well as to predict compressive moduli. To our knowledge, this is the first study presenting cartilage tissue-engineered constructs that capture the overall transient, equilibrium and dynamic biomechanical properties of human articular cartilage.

  14. Open innovation in networks

    DEFF Research Database (Denmark)

    Hu, Yimei

    Open innovation in networks has been a popular topic for long, this paper rethinks the concepts of innovation network and network organization, and clarifies the differences between them based on the network perspective. Network perspective means that: network is the context of firms; market...... and hierarchy can be analyzed from a network approach. Within a network perspective, there are different levels of network, and a firm may not always has the power to “manage” innovation networks due to different levels of power. Based on the strength of a firm’s power, its role may varies from manager...

  15. Neural coordination can be enhanced by occasional interruption of normal firing patterns: a self-optimizing spiking neural network model.

    Science.gov (United States)

    Woodward, Alexander; Froese, Tom; Ikegami, Takashi

    2015-02-01

    The state space of a conventional Hopfield network typically exhibits many different attractors of which only a small subset satisfies constraints between neurons in a globally optimal fashion. It has recently been demonstrated that combining Hebbian learning with occasional alterations of normal neural states avoids this problem by means of self-organized enlargement of the best basins of attraction. However, so far it is not clear to what extent this process of self-optimization is also operative in real brains. Here we demonstrate that it can be transferred to more biologically plausible neural networks by implementing a self-optimizing spiking neural network model. In addition, by using this spiking neural network to emulate a Hopfield network with Hebbian learning, we attempt to make a connection between rate-based and temporal coding based neural systems. Although further work is required to make this model more realistic, it already suggests that the efficacy of the self-optimizing process is independent from the simplifying assumptions of a conventional Hopfield network. We also discuss natural and cultural processes that could be responsible for occasional alteration of neural firing patterns in actual brains. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Bayesian network modeling applied to coastal geomorphology: lessons learned from a decade of experimentation and application

    Science.gov (United States)

    Plant, N. G.; Thieler, E. R.; Gutierrez, B.; Lentz, E. E.; Zeigler, S. L.; Van Dongeren, A.; Fienen, M. N.

    2016-12-01

    We evaluate the strengths and weaknesses of Bayesian networks that have been used to address scientific and decision-support questions related to coastal geomorphology. We will provide an overview of coastal geomorphology research that has used Bayesian networks and describe what this approach can do and when it works (or fails to work). Over the past decade, Bayesian networks have been formulated to analyze the multi-variate structure and evolution of coastal morphology and associated human and ecological impacts. The approach relates observable system variables to each other by estimating discrete correlations. The resulting Bayesian-networks make predictions that propagate errors, conduct inference via Bayes rule, or both. In scientific applications, the model results are useful for hypothesis testing, using confidence estimates to gage the strength of tests while applications to coastal resource management are aimed at decision-support, where the probabilities of desired ecosystems outcomes are evaluated. The range of Bayesian-network applications to coastal morphology includes emulation of high-resolution wave transformation models to make oceanographic predictions, morphologic response to storms and/or sea-level rise, groundwater response to sea-level rise and morphologic variability, habitat suitability for endangered species, and assessment of monetary or human-life risk associated with storms. All of these examples are based on vast observational data sets, numerical model output, or both. We will discuss the progression of our experiments, which has included testing whether the Bayesian-network approach can be implemented and is appropriate for addressing basic and applied scientific problems and evaluating the hindcast and forecast skill of these implementations. We will present and discuss calibration/validation tests that are used to assess the robustness of Bayesian-network models and we will compare these results to tests of other models. This will

  17. ENLIGHT Network

    CERN Multimedia

    Ballantine, A; Dixon-Altaber, H; Dosanjh, M; Kuchina, L

    2011-01-01

    State-of-the-art techniques borrowed from particle accelerators and detectors are a key element in hadrontherapy and several European projects are actively fostering the collaboration amongst the various disciplines and countries. ENLIGHT was established in 2002 to coordinate these European efforts in hadron therapy. The ENLIGHT network is formed by the European hadrontherapy Community, with more than 300 participants from twenty European countries. A major achievement of ENLIGHT has been the blending of traditionally separate communities so that clinicians, physicists, biologists and engineers with experience and interest in particle therapy are working together.

  18. Local Social Networks

    OpenAIRE

    Sapuppo, Antonio; Sørensen, Lene Tolstrup

    2011-01-01

    Online social networks have become essential for many users in their daily communication. Through a combination of the online social networks with opportunistic networks, a new concept arises: Local Social Networks. The target of local social networks is to promote social networking benefits in physical environment in order to leverage personal affinities in the users' surroundings. The purpose of this paper is to present and discuss the concept of local social networks as a new social commun...

  19. A biochemical network can control formation of a synthetic material by sensing numerous specific stimuli.

    Science.gov (United States)

    Hun Yeon, Ju; Chan, Karen Y T; Wong, Ting-Chia; Chan, Kelvin; Sutherland, Michael R; Ismagilov, Rustem F; Pryzdial, Edward L G; Kastrup, Christian J

    2015-05-15

    Developing bio-compatible smart materials that assemble in response to environmental cues requires strategies that can discriminate multiple specific stimuli in a complex milieu. Synthetic materials have yet to achieve this level of sensitivity, which would emulate the highly evolved and tailored reaction networks of complex biological systems. Here we show that the output of a naturally occurring network can be replaced with a synthetic material. Exploiting the blood coagulation system as an exquisite biological sensor, the fibrin clot end-product was replaced with a synthetic material under the biological control of a precisely regulated cross-linking enzyme. The functions of the coagulation network remained intact when the material was incorporated. Clot-like polymerization was induced in indirect response to distinct small molecules, phospholipids, enzymes, cells, viruses, an inorganic solid, a polyphenol, a polysaccharide, and a membrane protein. This strategy demonstrates for the first time that an existing stimulus-responsive biological network can be used to control the formation of a synthetic material by diverse classes of physiological triggers.

  20. High Fidelity Simulations of Large-Scale Wireless Networks (Plus-Up)

    Energy Technology Data Exchange (ETDEWEB)

    Onunkwo, Uzoma [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-11-01

    Sandia has built a strong reputation in scalable network simulation and emulation for cyber security studies to protect our nation’s critical information infrastructures. Georgia Tech has preeminent reputation in academia for excellence in scalable discrete event simulations, with strong emphasis on simulating cyber networks. Many of the experts in this field, such as Dr. Richard Fujimoto, Dr. George Riley, and Dr. Chris Carothers, have strong affiliations with Georgia Tech. The collaborative relationship that we intend to immediately pursue is in high fidelity simulations of practical large-scale wireless networks using ns-3 simulator via Dr. George Riley. This project will have mutual benefits in bolstering both institutions’ expertise and reputation in the field of scalable simulation for cyber-security studies. This project promises to address high fidelity simulations of large-scale wireless networks. This proposed collaboration is directly in line with Georgia Tech’s goals for developing and expanding the Communications Systems Center, the Georgia Tech Broadband Institute, and Georgia Tech Information Security Center along with its yearly Emerging Cyber Threats Report. At Sandia, this work benefits the defense systems and assessment area with promise for large-scale assessment of cyber security needs and vulnerabilities of our nation’s critical cyber infrastructures exposed to wireless communications.

  1. Integrated RF/Optical Interplanetary Networking Preliminary Explorations and Empirical Results

    Science.gov (United States)

    Raible, Daniel E.; Hylton, Alan G.

    2012-01-01

    Over the last decade interplanetary telecommunication capabilities have been significantly expanded--specifically in support of the Mars exploration rover and lander missions. NASA is continuing to drive advances in new, high payoff optical communications technologies to enhance the network to Gbps performance from Mars, and the transition from technology demonstration to operational system is examined through a hybrid RF/optical approach. Such a system combines the best features of RF and optical communications considering availability and performance to realize a dual band trunk line operating within characteristic constraints. Disconnection due to planetary obscuration and solar conjunction, link delays, timing, ground terminal mission congestion and scheduling policy along with space and atmospheric weather disruptions all imply the need for network protocol solutions to ultimately manage the physical layer in a transparent manner to the end user. Delay Tolerant Networking (DTN) is an approach under evaluation which addresses these challenges. A multi-hop multi-path hybrid RF and optical test bed has been constructed to emulate the integrated deep space network and to support protocol and hardware refinement. Initial experimental results characterize several of these challenges and evaluate the effectiveness of DTN as a solution to mitigate them.

  2. Avaliação da estabilidade da emulsão óleo/água proveniente dos resíduos de uma indústria beneficiadora de gemas frente ao uso de diferentes surfactantes

    Directory of Open Access Journals (Sweden)

    Simone Stülp

    2013-01-01

    Full Text Available A reutilização dos resíduos gerados pelos diversos setores industriais é uma prática que cada dia é mais utilizado, devido ao comprometimento das indústrias com sua responsabilidade social (proteção ao ambiente ou a exigências dos órgãos de proteção ambiental, já que muitos resíduos não possuem o devido descarte. Na indústria de beneficiamento de gemas a busca pelo reaproveitamento dos resíduos também tem se tornado uma realidade. O presente trabalho tem como objetivo avaliar o reaproveitamento do óleo utilizado como lubrificante na indústria de beneficiamento de gemas, juntamente com água, surfactantes e anticorrosivos. Para preparo das emulsões foram utilizadas amostras de óleo diesel utilizado como lubrificante no setor de corte deste tipo de indústria, mais os seguintes surfactantes: Tween 20, Tween 80, Lauril Éter Sulfato de Sódio (SLES e Cetiol HE. Depois de realizadas análises de pH, viscosidade, densidade e separação de fases nestas emulsões, chegou-se a conclusão que o surfactante Lauril Éter Sulfato de Sódio proporcionava a melhor formulação. Utilizando-se deste resultado, foram preparadas novas emulsões com o surfactante Lauril Éter Sulfato de Sódio e um anticorrosivo, neste caso, o molibdato de sódio. Nestas soluções contendo molibdato de sódio mais óleo e surfactante foram realizadas análises de resistência à corrosão deste sistema, utilizando-se de placas de aço SAE 1020, pela análise de perda de massa. Após estas análises, verificou-se que a adição de um anticorrosivo pode reduzir ou inibir a oxidação, mas em outros casos, como neste estudo, pode promover uma oxidação ainda maiorAbstract The reuse of waste generated by various industrial sectors is a practice that has been increasingly used due to impairment of industries with their social responsibility (environmental protection or the requirements of the protection of the environment, since many residues do not have

  3. Multinational Corporation as a Regional Economic Security Network

    Directory of Open Access Journals (Sweden)

    Aliona DANILIUC

    2016-12-01

    Full Text Available This paper is about multinational enterprises and regional security economic, summarizes and synthesizes different strands of literature, to present conclusions on the potential role of multinational enterprises in regional economic security in the EU, Ukraine, Moldova. The circumstances under which 'developmental' MNE subsidiaries may emerge in host regions are reviewed and possible routes to cluster formation and the generation of dynamic comparative advantage are explored. Policy issues are discussed, emphasizing the importance of investment in infrastructure, education and other public goods.

  4. Connectivity of communication networks

    CERN Document Server

    Mao, Guoqiang

    2017-01-01

    This book introduces a number of recent developments on connectivity of communication networks, ranging from connectivity of large static networks and connectivity of highly dynamic networks to connectivity of small to medium sized networks. This book also introduces some applications of connectivity studies in network optimization, in network localization, and in estimating distances between nodes. The book starts with an overview of the fundamental concepts, models, tools, and methodologies used for connectivity studies. The rest of the chapters are divided into four parts: connectivity of large static networks, connectivity of highly dynamic networks, connectivity of small to medium sized networks, and applications of connectivity studies.

  5. Network Science Experimentation Vision

    Science.gov (United States)

    2015-09-01

    capabilities and performance of a heterogeneous collection of interdependent networks . This report outlines and discusses an experimentation vision that...has been shown to depend upon the capabilities and performance of a heterogeneous collection of interdependent networks . Such a collection of networks ...well as tactical military networks . In particular, wireless tactical networks can be simulated with high fidelity, using off the shelf simulation

  6. Evolving Transport Networks With Cellular Automata Models Inspired by Slime Mould.

    Science.gov (United States)

    Tsompanas, Michail-Antisthenis I; Sirakoulis, Georgios Ch; Adamatzky, Andrew I

    2015-09-01

    Man-made transport networks and their design are closely related to the shortest path problem and considered amongst the most debated problems of computational intelligence. Apart from using conventional or bio-inspired computer algorithms, many researchers tried to solve this kind of problem using biological computing substrates, gas-discharge solvers, prototypes of a mobile droplet, and hot ice computers. In this aspect, another example of biological computer is the plasmodium of acellular slime mould Physarum polycephalum (P. polycephalum), which is a large single cell visible by an unaided eye and has been proven as a reliable living substrate for implementing biological computing devices for computational geometry, graph-theoretical problems, and optimization and imitation of transport networks. Although P. polycephalum is easy to experiment with, computing devices built with the living slime mould are extremely slow; it takes slime mould days to execute a computation. Consequently, mapping key computing mechanisms of the slime mould onto silicon would allow us to produce efficient bio-inspired computing devices to tackle with hard to solve computational intelligence problems like the aforementioned. Toward this direction, a cellular automaton (CA)-based, Physarum-inspired, network designing model is proposed. This novel CA-based model is inspired by the propagating strategy, the formation of tubular networks, and the computing abilities of the plasmodium of P. polycephalum. The results delivered by the CA model demonstrate a good match with several previously published results of experimental laboratory studies on imitation of man-made transport networks with P. polycephalum. Consequently, the proposed CA model can be used as a virtual, easy-to-access, and biomimicking laboratory emulator that will economize large time periods needed for biological experiments while producing networks almost identical to the tubular networks of the real-slime mould.

  7. Analog memristive synapse in spiking networks implementing unsupervised learning

    Directory of Open Access Journals (Sweden)

    Erika Covi

    2016-10-01

    Full Text Available Emerging brain-inspired architectures call for devices that can emulate the functionality of biological synapses in order to implement new efficient computational schemes able to solve ill-posed problems. Various devices and solutions are still under investigation and, in this respect, a challenge is opened to the researchers in the field. Indeed, the optimal candidate is a device able to reproduce the complete functionality of a synapse, i.e. the typical synaptic process underlying learning in biological systems (activity-dependent synaptic plasticity. This implies a device able to change its resistance (synaptic strength, or weight upon proper electrical stimuli (synaptic activity and showing several stable resistive states throughout its dynamic range (analog behavior. Moreover, it should be able to perform spike timing dependent plasticity (STDP, an associative homosynaptic plasticity learning rule based on the delay time between the two firing neurons the synapse is connected to. This rule is a fundamental learning protocol in state-of-art networks, because it allows unsupervised learning. Notwithstanding this fact, STDP-based unsupervised learning has been proposed several times mainly for binary synapses rather than multilevel synapses composed of many binary memristors. This paper proposes an HfO2-based analog memristor as a synaptic element which performs STDP within a small spiking neuromorphic network operating unsupervised learning for character recognition. The trained network is able to recognize five characters even in case incomplete or noisy characters are displayed and it is robust to a device-to-device variability of up to +/-30%.

  8. Network characteristics for server selection in online games

    Science.gov (United States)

    Claypool, Mark

    2008-01-01

    Online gameplay is impacted by the network characteristics of players connected to the same server. Unfortunately, the network characteristics of online game servers are not well-understood, particularly for groups that wish to play together on the same server. As a step towards a remedy, this paper presents analysis of an extensive set of measurements of game servers on the Internet. Over the course of many months, actual Internet game servers were queried simultaneously by twenty-five emulated game clients, with both servers and clients spread out on the Internet. The data provides statistics on the uptime and populations of game servers over a month long period an an in-depth look at the suitability for game servers for multi-player server selection, concentrating on characteristics critical to playability--latency and fairness. Analysis finds most game servers have latencies suitable for third-person and omnipresent games, such as real-time strategy, sports and role-playing games, providing numerous server choices for game players. However, far fewer game servers have the low latencies required for first-person games, such as shooters or race games. In all cases, groups that wish to play together have a greatly reduced set of servers from which to choose because of inherent unfairness in server latencies and server selection is particularly limited as the group size increases. These results hold across different game types and even across different generations of games. The data should be useful for game developers and network researchers that seek to improve game server selection, whether for single or multiple players.

  9. Introduction to computer networking

    CERN Document Server

    Robertazzi, Thomas G

    2017-01-01

    This book gives a broad look at both fundamental networking technology and new areas that support it and use it. It is a concise introduction to the most prominent, recent technological topics in computer networking. Topics include network technology such as wired and wireless networks, enabling technologies such as data centers, software defined networking, cloud and grid computing and applications such as networks on chips, space networking and network security. The accessible writing style and non-mathematical treatment makes this a useful book for the student, network and communications engineer, computer scientist and IT professional. • Features a concise, accessible treatment of computer networking, focusing on new technological topics; • Provides non-mathematical introduction to networks in their most common forms today;< • Includes new developments in switching, optical networks, WiFi, Bluetooth, LTE, 5G, and quantum cryptography.

  10. Animal transportation networks

    Science.gov (United States)

    Perna, Andrea; Latty, Tanya

    2014-01-01

    Many group-living animals construct transportation networks of trails, galleries and burrows by modifying the environment to facilitate faster, safer or more efficient movement. Animal transportation networks can have direct influences on the fitness of individuals, whereas the shape and structure of transportation networks can influence community dynamics by facilitating contacts between different individuals and species. In this review, we discuss three key areas in the study of animal transportation networks: the topological properties of networks, network morphogenesis and growth, and the behaviour of network users. We present a brief primer on elements of network theory, and then discuss the different ways in which animal groups deal with the fundamental trade-off between the competing network properties of travel efficiency, robustness and infrastructure cost. We consider how the behaviour of network users can impact network efficiency, and call for studies that integrate both network topology and user behaviour. We finish with a prospectus for future research. PMID:25165598

  11. Visualization of Social Networks

    NARCIS (Netherlands)

    Boertjes, E.M.; Kotterink, B.; Jager, E.J.

    2011-01-01

    Current visualizations of social networks are mostly some form of node-link diagram. Depending on the type of social network, this can be some treevisualization with a strict hierarchical structure or a more generic network visualization.

  12. Collaborative networks: Reference modeling

    NARCIS (Netherlands)

    Camarinha-Matos, L.M.; Afsarmanesh, H.

    2008-01-01

    Collaborative Networks: Reference Modeling works to establish a theoretical foundation for Collaborative Networks. Particular emphasis is put on modeling multiple facets of collaborative networks and establishing a comprehensive modeling framework that captures and structures diverse perspectives of

  13. Encapsulamento do Dióxido de Titânio (TiO2 pela Técnica de Polimerização em Emulsão

    Directory of Open Access Journals (Sweden)

    Oliveira Adriano M.

    2002-01-01

    Full Text Available Este trabalho apresenta uma metodologia de encapsulamento do TiO2 pela técnica de polimerização em emulsão. O pigmento foi previamente modificado por um titanato em heptano. O titanato usado foi o tri-isoestearato iso-propoxi de titânio, que reage com os grupos hidroxilas da superfície do TiO2. O pigmento modificado foi encapsulado por metacrilato de metila (MMA, usando persulfato de amônio como iniciador e dodecil sulfato de sódio (SDS como emulsificante. A reação de encapsulamento foi conduzida em um reator de vidro encamisado, utilizando dois processos de polimerização diferentes: batelada e semi-contínuo. A caracterização do pigmento modificado foi feita pela técnica de Infravermelho com Transformada de Fourier (FTIR. Os rendimentos das reações de modificação e de encapsulamento foram determinados pela técnica de Análise Termogravimétrica (TGA.

  14. Computer networks monitoring

    OpenAIRE

    Antončič , Polona

    2012-01-01

    The present thesis entitled Computer Networks Monitoring introduces the basics of computer networks, the aim and the computer data reclamation from networking devices, software for the system follow-up together with the case of monitoring a real network with tens of network devices. The networks represent an important part in the modern information technology and serve for the exchange of data and sources which makes their impeccability of crucial importance. Correct and efficient sys...

  15. Packet Tracer network simulator

    CERN Document Server

    Jesin, A

    2014-01-01

    A practical, fast-paced guide that gives you all the information you need to successfully create networks and simulate them using Packet Tracer.Packet Tracer Network Simulator is aimed at students, instructors, and network administrators who wish to use this simulator to learn how to perform networking instead of investing in expensive, specialized hardware. This book assumes that you have a good amount of Cisco networking knowledge, and it will focus more on Packet Tracer rather than networking.

  16. Basics of Computer Networking

    CERN Document Server

    Robertazzi, Thomas

    2012-01-01

    Springer Brief Basics of Computer Networking provides a non-mathematical introduction to the world of networks. This book covers both technology for wired and wireless networks. Coverage includes transmission media, local area networks, wide area networks, and network security. Written in a very accessible style for the interested layman by the author of a widely used textbook with many years of experience explaining concepts to the beginner.

  17. Percolation in clustered networks

    OpenAIRE

    Miller, Joel C

    2009-01-01

    The social networks that infectious diseases spread along are typically clustered. Because of the close relation between percolation and epidemic spread, the behavior of percolation in such networks gives insight into infectious disease dynamics. A number of authors have studied clustered networks, but the networks often contain preferential mixing between high degree nodes. We introduce a class of random clustered networks and another class of random unclustered networks with the same prefer...

  18. Cyber Network Mission Dependencies

    Science.gov (United States)

    2015-09-18

    or she must make. Network Mapping System ( NeMS ) is a software-based tool created by the Lawrence Livermore National Laboratory to discover and map...network assets in support of cyber situational awareness [10]. NeMS combines both active probes and passive monitoring of network data to map the network...security settings in order to maximize efficiency without disrupting network activities. Tests of NeMS in control networks yielded great results, as

  19. The Economics of Networking

    DEFF Research Database (Denmark)

    Sørensen, Olav Jull

    The literature on business networks is often oversocialized. The economic side of business is implicitly assumed. This paper analyses the economics of network behavior by loking at each of the key concepts in the Network Theory.......The literature on business networks is often oversocialized. The economic side of business is implicitly assumed. This paper analyses the economics of network behavior by loking at each of the key concepts in the Network Theory....

  20. Stem Cell Networks

    OpenAIRE

    Werner, Eric

    2016-01-01

    We present a general computational theory of stem cell networks and their developmental dynamics. Stem cell networks are special cases of developmental control networks. Our theory generates a natural classification of all possible stem cell networks based on their network architecture. Each stem cell network has a unique topology and semantics and developmental dynamics that result in distinct phenotypes. We show that the ideal growth dynamics of multicellular systems generated by stem cell ...

  1. Statistical network analysis for analyzing policy networks

    DEFF Research Database (Denmark)

    Robins, Garry; Lewis, Jenny; Wang, Peng

    2012-01-01

    To analyze social network data using standard statistical approaches is to risk incorrect inference. The dependencies among observations implied in a network conceptualization undermine standard assumptions of the usual general linear models. One of the most quickly expanding areas of social...... and policy network methodology is the development of statistical modeling approaches that can accommodate such dependent data. In this article, we review three network statistical methods commonly used in the current literature: quadratic assignment procedures, exponential random graph models (ERGMs...

  2. Airborne Network Optimization with Dynamic Network Update

    Science.gov (United States)

    2015-03-26

    Faculty Department of Electrical and Computer Engineering Graduate School of Engineering and Management Air Force Institute of Technology Air University...require small amounts of network bandwidth to perform routing. This thesis advocates the use of Kalman filters to predict network congestion in...airborne networks. Intelligent agents can make use of Kalman filter predictions to make informed decisions to manage communication in airborne networks. The

  3. Next Generation Networks

    Directory of Open Access Journals (Sweden)

    Ladislav Schwartz

    2006-01-01

    Full Text Available Two network types had been existing in Slovakia by the end of the year 2004 – public switched telephone network – PSTN and packet switched data network – DCN. The other network, known as the next generation network – NGN, has been put into operation since the beginning of the year 2005. The role of the next generation network is to merge the both previous network types into one unified complex network with the full centralised control, based on routing and packet switching. The T-Com company (previous Slovak Telecom was the first who did it.

  4. Coded Network Function Virtualization

    DEFF Research Database (Denmark)

    Al-Shuwaili, A.; Simone, O.; Kliewer, J.

    2016-01-01

    Network function virtualization (NFV) prescribes the instantiation of network functions on general-purpose network devices, such as servers and switches. While yielding a more flexible and cost-effective network architecture, NFV is potentially limited by the fact that commercial off-the-shelf ha......Network function virtualization (NFV) prescribes the instantiation of network functions on general-purpose network devices, such as servers and switches. While yielding a more flexible and cost-effective network architecture, NFV is potentially limited by the fact that commercial off...

  5. Local Social Networks

    DEFF Research Database (Denmark)

    Sapuppo, Antonio; Sørensen, Lene Tolstrup

    2011-01-01

    in physical environment in order to leverage personal affinities in the users' surroundings. The purpose of this paper is to present and discuss the concept of local social networks as a new social communication system. Particularly, the preliminary architecture and the prototype of local social networks......Online social networks have become essential for many users in their daily communication. Through a combination of the online social networks with opportunistic networks, a new concept arises: Local Social Networks. The target of local social networks is to promote social networking benefits...

  6. Didactic Strategy Discussion Based on Artificial Neural Networks Results.

    Science.gov (United States)

    Andina, D.; Bermúdez-Valbuena, R.

    2009-04-01

    Artificial Neural Networks (ANNs) are a mathematical model of the main known characteristics of biological brian dynamics. ANNs inspired in biological reality have been useful to design machines that show some human-like behaviours. Based on them, many experimentes have been succesfully developed emulating several biologial neurons characteristics, as learning how to solve a given problem. Sometimes, experimentes on ANNs feedback to biology and allow advances in understanding the biological brian behaviour, allowing the proposal of new therapies for medical problems involving neurons performing. Following this line, the author present results on artificial learning on ANN, and interpret them aiming to reinforce one of this two didactic estrategies to learn how to solve a given difficult task: a) To train with clear, simple, representative examples and feel confidence in brian generalization capabilities to achieve succes in more complicated cases. b) To teach with a set of difficult cases of the problem feeling confidence that the brian will efficiently solve the rest of cases if it is able to solve the difficult ones. Results may contribute in the discussion of how to orientate the design innovative succesful teaching strategies in the education field.

  7. Mimicking Synaptic Plasticity and Neural Network Using Memtranstors.

    Science.gov (United States)

    Shen, Jian-Xin; Shang, Da-Shan; Chai, Yi-Sheng; Wang, Shou-Guo; Shen, Bao-Gen; Sun, Young

    2018-02-05

    Artificial synaptic devices that mimic the functions of biological synapses have drawn enormous interest because of their potential in developing brain-inspired computing. Current studies are focusing on memristive devices in which the change of the conductance state is used to emulate synaptic behaviors. Here, a new type of artificial synaptic devices based on the memtranstor is demonstrated, which is a fundamental circuit memelement in addition to the memristor, memcapacitor, and meminductor. The state of transtance (presented by the magnetoelectric voltage) in memtranstors acting as the synaptic weight can be tuned continuously with a large number of nonvolatile levels by engineering the applied voltage pulses. Synaptic behaviors including the long-term potentiation, long-term depression, and spiking-time-dependent plasticity are implemented in memtranstors made of Ni/0.7Pb(Mg 1/3 Nb 2/3 )O 3 -0.3PbTiO 3 /Ni multiferroic heterostructures. Simulations reveal the capability of pattern learning in a memtranstor network. The work elucidates the promise of memtranstors as artificial synaptic devices with low energy consumption. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Formation of multiple networks

    DEFF Research Database (Denmark)

    Magnani, Matteo; Rossi, Luca

    2013-01-01

    While most research in Social Network Analysis has focused on single networks, the availability of complex on-line data about individuals and their mutual heterogenous connections has recently determined a renewed interest in multi-layer network analysis. To the best of our knowledge, in this paper...... we introduce the first network formation model for multiple networks. Network formation models are among the most popular tools in traditional network studies, because of both their practical and theoretical impact. However, existing models are not sufficient to describe the generation of multiple...... networks. Our model, motivated by an empirical analysis of real multi-layered network data, is a conservative extension of single-network models and emphasizes the additional level of complexity that we experience when we move from a single- to a more complete and realistic multi-network context....

  9. Noisy Network Coding

    CERN Document Server

    Lim, Sung Hoon; Gamal, Abbas El; Chung, Sae-Young

    2010-01-01

    A noisy network coding scheme for sending multiple sources over a general noisy network is presented. For multi-source multicast networks, the scheme naturally extends both network coding over noiseless networks by Ahlswede, Cai, Li, and Yeung, and compress-forward coding for the relay channel by Cover and El Gamal to general discrete memoryless and Gaussian networks. The scheme also recovers as special cases the results on coding for wireless relay networks and deterministic networks by Avestimehr, Diggavi, and Tse, and coding for wireless erasure networks by Dana, Gowaikar, Palanki, Hassibi, and Effros. The scheme involves message repetition coding, relay signal compression, and simultaneous decoding. Unlike previous compress--forward schemes, where independent messages are sent over multiple blocks, the same message is sent multiple times using independent codebooks as in the network coding scheme for cyclic networks. Furthermore, the relays do not use Wyner--Ziv binning as in previous compress-forward sch...

  10. Identity and Professional Networking.

    Science.gov (United States)

    Raj, Medha; Fast, Nathanael J; Fisher, Oliver

    2017-06-01

    Despite evidence that large professional networks afford a host of financial and professional benefits, people vary in how motivated they are to build such networks. To help explain this variance, the present article moves beyond a rational self-interest account to examine the possibility that identity shapes individuals' intentions to network. Study 1 established a positive association between viewing professional networking as identity-congruent and the tendency to prioritize strengthening and expanding one's professional network. Study 2 revealed that manipulating the salience of the self affects networking intentions, but only among those high in networking identity-congruence. Study 3 further established causality by experimentally manipulating identity-congruence to increase networking intentions. Study 4 examined whether identity or self-interest is a better predictor of networking intentions, providing support for the former. These findings indicate that identity influences the networks people develop. Implications for research on the self, identity-based motivation, and professional networking are discussed.

  11. Eestlase rahakott paisub ELi keskmiseni paarikümne aastaga / Hindrek Riikoja

    Index Scriptorium Estoniae

    Riikoja, Hindrek

    2006-01-01

    Ilmunud ka: Postimees : na russkom jazõke 4. juuli lk. 9. Euroopa Liidu statistikaameti Eurostat teostatud uuringu kohaselt moodustab Eesti ostujõud Euroopa Liidu keskmisest 57 protsenti. Euroopa keskmiseni jõudmiseks kulub Eestil vähemalt paarkümmend aastat. Diagramm: Eesti ostujõud moodustab poole ELi omast

  12. The MNE as a challenge to institutional theory: Key concepts, recent developments and empirical evidence

    NARCIS (Netherlands)

    Saka-Helmhout, A.U.; Deeg, R.; Greenwood, R.

    2016-01-01

    The co-existence of multiple, often contradictory, institutional demands pose challenges to organizations. Despite the intriguing context that multinational enterprises (MNEs) present for the study of organizational action to such demands, research has focused on organizational fields. To more

  13. Anonüümne aidsitest on lihtsamast lihtne / Agnes Kuus

    Index Scriptorium Estoniae

    Kuus, Agnes

    2005-01-01

    Autor käis neljas anonüümses aidsikabinetis teste tegemas, et omal nahal veenduda, kas testijatele vaadatakse viltu, nagu väidavad anonüümsed netikommentaatorid. Vt. ka juhtkirja lk. 4: Piisake meres. Lisa: Anonüümsed ja tasuta aidsikabinetid

  14. MNE translation of corporate talent management strategies to subsidiaries in emerging economies

    NARCIS (Netherlands)

    Beamond, Maria Teresa; Farndale, Elaine; Härtel, Charmine E.j.

    2016-01-01

    The rise of emerging economies in recent years has motivated calls for research into how multinational enterprises translate their corporate strategies to subsidiaries in these countries. This study addresses this issue and presents a heuristic framework derived from the resource-based view and

  15. The Export Performance of MNE Affiliates in Polish manufacturing: 1993-2002

    DEFF Research Database (Denmark)

    Nielsen, Jørgen Ulff-Møller; Pawlik, Konrad

    2006-01-01

    affiliates is the result of increasing international sourcing, implying that the foreign affiliates hold an advanced role in MNEs, which translates its "knowledge mandate" into more trade (imports and exports) in interdependence with other foreign affiliates. High wages to foreign affiliate employees...... (indicating improvements in absorptive capacity) are related to high export performance. Besides, given international business research (Kogut and Zander, 1993), the positive association between foreign ownership and export intensity suggests that transfer of tacit knowledge is positively related to affiliate...... are significant and positively associated to export performance, while investment activity is negatively related to the export performance of the affiliates. On the assumption that some industry variables are proxies for technology transfer, the results show that the increasing export orientation of foreign...

  16. Kontserdikaja : David Oistrahhi Festival. Pärnu Linnaorkestri hommik kümne dirigendiga / Toomas Velmet

    Index Scriptorium Estoniae

    Velmet, Toomas, 1942-

    2004-01-01

    Pärnu Linnaorkestri ja Neeme Järvi suveakadeemia dirigentide hommikukontserdist Pärnu kontserdimajas 7. juulil. Külli Tomingase, Kaunase keelpillikvarteti ja Antti Siirala kontserdist Pärnu raekojas 7. juulil

  17. The hybridization of local MNE production systems : The case of subsidiaries in India

    NARCIS (Netherlands)

    Becker-Ritterspach, F.A.A.

    2006-01-01

    This work is about the transfer and contextual constitution of organisational forms (specifically of production systems) in the subsidiaries of multinational enterprises (MNEs). The work suggests that subsidiaries are simultaneously embedded in a host country and parent company context as well as in

  18. Determinants of MNE Activity in Poland: The Case of Firms from EU-15

    Directory of Open Access Journals (Sweden)

    Andrzej Cieślik

    2017-03-01

    Full Text Available Objective: The main purpose of this paper is to validate empirically the theoretical predictions of the modified knowledge capital model of multinational enterprise and identify the main reasons for undertaking international production in Poland by foreign firms from the EU-15 countries. Research Design & Methods: Our theoretical framework refers to the physical capital augmented knowledge capital model that combines both horizontal and vertical reasons for foreign direct investment. The empirical implementation of the theoretical framework is based on the negative binomial model and the bilateral dataset covering 15 old EU member states over the period 1989-2014 which yields a total of 390 observations. Findings: Our estimation results indicate that the extent of multinational activity in Poland is positively related to both differences in relative factor endowments and similarity in the relative country size which confirms the importance of both reasons for undertaking foreign direct investment in Poland. Implications & Recommendations: The empirical evidence confirms the predictions of the modified knowledge capital model and points to the horizontal as well as vertical motives for undertaking foreign direct investment in Poland. These findings suggest that government should not try to attract only one type of FDI. Contribution & Value Added: The originality of this work lies in the empirical implementation of the theoretical framework that allows distinguishing between horizontal and vertical reasons for foreign direct investment.

  19. Why do MNE Subsidiaries Outsource R&D in Countries with Weaker National IPR Regimes?

    DEFF Research Database (Denmark)

    Santangelo, Grazia D.; Meyer, Klaus; Jindra, Björn

    2014-01-01

    subsidiaries increasingly outsource R&D to local contractors in weaker IPR countries. Drawing on institutional and transaction costs economics, we address this gap and argue that the quality of subnational institutions plays a contractual hazard-mitigating role that may at least partially compensate...

  20. Aleksandr Shilov : mne bõlo stõdno rabotat gruztshikom / Aleksandr Shilov ; interv. Jelena Fomina

    Index Scriptorium Estoniae

    Shilov, Aleksandr

    2003-01-01

    6. oktoobril 2003 saab 60 aastaseks Aleksandr Shilov, Venemaa Kunstiakadeemia akadeemik, tuntud portretist, kelle nimi on omistatud uuele planeedile. Kunstnikuga tema lapsepõlvest, õpingutest, loomingust. Moskvas on avatud A. M. Shilovi Riiklik Galerii