Science.gov

Sample records for networked linux systems

  1. Network of networks in Linux operating system

    NASA Astrophysics Data System (ADS)

    Wang, Haoqin; Chen, Zhen; Xiao, Guanping; Zheng, Zheng

    2016-04-01

    Operating system represents one of the most complex man-made systems. In this paper, we analyze Linux Operating System (LOS) as a complex network via modeling functions as nodes and function calls as edges. It is found that for the LOS network and modularized components within it, the out-degree follows an exponential distribution and the in-degree follows a power-law distribution. For better understanding the underlying design principles of LOS, we explore the coupling correlations of components in LOS from aspects of topology and function. The result shows that the component for device drivers has a strong manifestation in topology while a weak manifestation in function. However, the component for process management shows the contrary phenomenon. Moreover, in an effort to investigate the impact of system failures on networks, we make a comparison between the networks traced from normal and failure status of LOS. This leads to a conclusion that the failure will change function calls which should be executed in normal status and introduce new function calls in the meanwhile.

  2. Evolution of Linux operating system network

    NASA Astrophysics Data System (ADS)

    Xiao, Guanping; Zheng, Zheng; Wang, Haoqin

    2017-01-01

    Linux operating system (LOS) is a sophisticated man-made system and one of the most ubiquitous operating systems. However, there is little research on the structure and functionality evolution of LOS from the prospective of networks. In this paper, we investigate the evolution of the LOS network. 62 major releases of LOS ranging from versions 1.0 to 4.1 are modeled as directed networks in which functions are denoted by nodes and function calls are denoted by edges. It is found that the size of the LOS network grows almost linearly, while clustering coefficient monotonically decays. The degree distributions are almost the same: the out-degree follows an exponential distribution while both in-degree and undirected degree follow power-law distributions. We further explore the functionality evolution of the LOS network. It is observed that the evolution of functional modules is shown as a sequence of seven events (changes) succeeding each other, including continuing, growth, contraction, birth, splitting, death and merging events. By means of a statistical analysis of these events in the top 4 largest components (i.e., arch, drivers, fs and net), it is shown that continuing, growth and contraction events occupy more than 95% events. Our work exemplifies a better understanding and describing of the dynamics of LOS evolution.

  3. Interactivity vs. fairness in networked linux systems

    SciTech Connect

    Wu, Wenji; Crawford, Matt; /Fermilab

    2007-01-01

    In general, the Linux 2.6 scheduler can ensure fairness and provide excellent interactive performance at the same time. However, our experiments and mathematical analysis have shown that the current Linux interactivity mechanism tends to incorrectly categorize non-interactive network applications as interactive, which can lead to serious fairness or starvation issues. In the extreme, a single process can unjustifiably obtain up to 95% of the CPU! The root cause is due to the facts that: (1) network packets arrive at the receiver independently and discretely, and the 'relatively fast' non-interactive network process might frequently sleep to wait for packet arrival. Though each sleep lasts for a very short period of time, the wait-for-packet sleeps occur so frequently that they lead to interactive status for the process. (2) The current Linux interactivity mechanism provides the possibility that a non-interactive network process could receive a high CPU share, and at the same time be incorrectly categorized as 'interactive.' In this paper, we propose and test a possible solution to address the interactivity vs. fairness problems. Experiment results have proved the effectiveness of the proposed solution.

  4. Convolutional Neural Network on Embedded Linux System-on-Chip: A Methodology and Performance Benchmark

    DTIC Science & Technology

    2016-05-01

    heat sink. Note that a final system could be made much smaller than this development board, which has “wasted” space compared to a board used in a...TECHNICAL REPORT 3010 May 2016 Convolutional Neural Network on Embedded Linux® System -on-Chip A Methodology and Performance Benchmark Daniel...in this report was performed by the IO Support to National Security Branch (Code 56120), the Mission Systems Engineering Branch (Code 56170), and the

  5. The Linux operating system: An introduction

    NASA Technical Reports Server (NTRS)

    Bokhari, Shahid H.

    1995-01-01

    Linux is a Unix-like operating system for Intel 386/486/Pentium based IBM-PCs and compatibles. The kernel of this operating system was written from scratch by Linus Torvalds and, although copyrighted by the author, may be freely distributed. A world-wide group has collaborated in developing Linux on the Internet. Linux can run the powerful set of compilers and programming tools of the Free Software Foundation, and XFree86, a port of the X Window System from MIT. Most capabilities associated with high performance workstations, such as networking, shared file systems, electronic mail, TeX, LaTeX, etc. are freely available for Linux. It can thus transform cheap IBM-PC compatible machines into Unix workstations with considerable capabilities. The author explains how Linux may be obtained, installed and networked. He also describes some interesting applications for Linux that are freely available. The enormous consumer market for IBM-PC compatible machines continually drives down prices of CPU chips, memory, hard disks, CDROMs, etc. Linux can convert such machines into powerful workstations that can be used for teaching, research and software development. For professionals who use Unix based workstations at work, Linux permits virtually identical working environments on their personal home machines. For cost conscious educational institutions Linux can create world-class computing environments from cheap, easily maintained, PC clones. Finally, for university students, it provides an essentially cost-free path away from DOS into the world of Unix and X Windows.

  6. The performance analysis of linux networking - packet receiving

    SciTech Connect

    Wu, Wenji; Crawford, Matt; Bowden, Mark; /Fermilab

    2006-11-01

    The computing models for High-Energy Physics experiments are becoming ever more globally distributed and grid-based, both for technical reasons (e.g., to place computational and data resources near each other and the demand) and for strategic reasons (e.g., to leverage equipment investments). To support such computing models, the network and end systems, computing and storage, face unprecedented challenges. One of the biggest challenges is to transfer scientific data sets--now in the multi-petabyte (10{sup 15} bytes) range and expected to grow to exabytes within a decade--reliably and efficiently among facilities and computation centers scattered around the world. Both the network and end systems should be able to provide the capabilities to support high bandwidth, sustained, end-to-end data transmission. Recent trends in technology are showing that although the raw transmission speeds used in networks are increasing rapidly, the rate of advancement of microprocessor technology has slowed down. Therefore, network protocol-processing overheads have risen sharply in comparison with the time spent in packet transmission, resulting in degraded throughput for networked applications. More and more, it is the network end system, instead of the network, that is responsible for degraded performance of network applications. In this paper, the Linux system's packet receive process is studied from NIC to application. We develop a mathematical model to characterize the Linux packet receiving process. Key factors that affect Linux systems network performance are analyzed.

  7. Implementing Journaling in a Linux Shared Disk File System

    NASA Technical Reports Server (NTRS)

    Preslan, Kenneth W.; Barry, Andrew; Brassow, Jonathan; Cattelan, Russell; Manthei, Adam; Nygaard, Erling; VanOort, Seth; Teigland, David; Tilstra, Mike; O'Keefe, Matthew; Erickson, Grant; Agarwal, Manish

    2000-01-01

    In computer systems today, speed and responsiveness is often determined by network and storage subsystem performance. Faster, more scalable networking interfaces like Fibre Channel and Gigabit Ethernet provide the scaffolding from which higher performance computer systems implementations may be constructed, but new thinking is required about how machines interact with network-enabled storage devices. In this paper we describe how we implemented journaling in the Global File System (GFS), a shared-disk, cluster file system for Linux. Our previous three papers on GFS at the Mass Storage Symposium discussed our first three GFS implementations, their performance, and the lessons learned. Our fourth paper describes, appropriately enough, the evolution of GFS version 3 to version 4, which supports journaling and recovery from client failures. In addition, GFS scalability tests extending to 8 machines accessing 8 4-disk enclosures were conducted: these tests showed good scaling. We describe the GFS cluster infrastructure, which is necessary for proper recovery from machine and disk failures in a collection of machines sharing disks using GFS. Finally, we discuss the suitability of Linux for handling the big data requirements of supercomputing centers.

  8. Diversifying the Department of Defense Network Enterprise with Linux

    DTIC Science & Technology

    2010-03-01

    Cyberspace, Cyberwar, Legacy, Inventory, Acquisition, Competitive Advantage, Coalition Communications, Ubiquitous, Strategic, Centricity, Kaizen , ISO... Kaizen , ISO, Outsource CLASSIFICATION: Unclassified Historically, the United States and its closest allies have grown increasingly reliant...control through the use of continuous improvement processes ( Kaizen )34. In choosing the Linux client operating system, the move encourages open standards

  9. Building CHAOS: An Operating System for Livermore Linux Clusters

    SciTech Connect

    Garlick, J E; Dunlap, C M

    2003-02-21

    The Livermore Computing (LC) Linux Integration and Development Project (the Linux Project) produces and supports the Clustered High Availability Operating System (CHAOS), a cluster operating environment based on Red Hat Linux. Each CHAOS release begins with a set of requirements and ends with a formally tested, packaged, and documented release suitable for use on LC's production Linux clusters. One characteristic of CHAOS is that component software packages come from different sources under varying degrees of project control. Some are developed by the Linux Project, some are developed by other LC projects, some are external open source projects, and some are commercial software packages. A challenge to the Linux Project is to adhere to release schedules and testing disciplines in a diverse, highly decentralized development environment. Communication channels are maintained for externally developed packages in order to obtain support, influence development decisions, and coordinate/understand release schedules. The Linux Project embraces open source by releasing locally developed packages under open source license, by collaborating with open source projects where mutually beneficial, and by preferring open source over proprietary software. Project members generally use open source development tools. The Linux Project requires system administrators and developers to work together to resolve problems that arise in production. This tight coupling of production and development is a key strategy for making a product that directly addresses LC's production requirements. It is another challenge to balance support and development activities in such a way that one does not overwhelm the other.

  10. CompactPCI/Linux Platform in FTU Slow Control System

    NASA Astrophysics Data System (ADS)

    Iannone, F.; Wang, L.; Centioli, C.; Panella, M.; Mazza, G.; Vitale, V.

    2004-12-01

    In large fusion experiments, such as tokamak devices, there is a common trend for slow control systems. Because of complexity of the plants, the so-called `Standard Model' (SM) in slow control has been adopted on several tokamak machines. This model is based on a three-level hierarchical control: 1) High-Level Control (HLC) with a supervisory function; 2) Medium-Level Control (MLC) to interface and concentrate I/O field equipments; 3) Low-Level Control (LLC) with hard real-time I/O function, often managed by PLCs. FTU control system designed with SM concepts has underwent several stages of developments in its fifteen years duration of runs. The latest evolution was inevitable, due to the obsolescence of the MLC CPUs, based on VME-MOTOROLA 68030 with OS9 operating system. A large amount of C code was developed for that platform to route the data flow from LLC, which is constituted by 24 Westinghouse Numalogic PC-700 PLCs with about 8000 field-points, to HLC, based on a commercial Object-Oriented Real-Time database on Alpha/CompaqTru64 platform. Therefore, we have to look for cost-effective solutions and finally a CompactPCI-Intel x86 platform with Linux operating system was chosen. A software porting has been done, taking into account the differences between OS9 and Linux operating system in terms of Inter/Network Processes Communications and I/O multi-ports serial driver. This paper describes the hardware/software architecture of the new MLC system, emphasizing the reliability and the low costs of the open source solutions. Moreover, a huge amount of software packages available in open source environment will assure a less painful maintenance, and will open the way to further improvements of the system itself.

  11. Construction of a Linux based chemical and biological information system.

    PubMed

    Molnár, László; Vágó, István; Fehér, András

    2003-01-01

    A chemical and biological information system with a Web-based easy-to-use interface and corresponding databases has been developed. The constructed system incorporates all chemical, numerical and textual data related to the chemical compounds, including numerical biological screen results. Users can search the database by traditional textual/numerical and/or substructure or similarity queries through the web interface. To build our chemical database management system, we utilized existing IT components such as ORACLE or Tripos SYBYL for database management and Zope application server for the web interface. We chose Linux as the main platform, however, almost every component can be used under various operating systems.

  12. Potential performance bottleneck in Linux TCP

    SciTech Connect

    Wu, Wenji; Crawford, Matt; /Fermilab

    2006-12-01

    TCP is the most widely used transport protocol on the Internet today. Over the years, especially recently, due to requirements of high bandwidth transmission, various approaches have been proposed to improve TCP performance. The Linux 2.6 kernel is now preemptible. It can be interrupted mid-task, making the system more responsive and interactive. However, we have noticed that Linux kernel preemption can interact badly with the performance of the networking subsystem. In this paper we investigate the performance bottleneck in Linux TCP. We systematically describe the trip of a TCP packet from its ingress into a Linux network end system to its final delivery to the application; we study the performance bottleneck in Linux TCP through mathematical modeling and practical experiments; finally we propose and test one possible solution to resolve this performance bottleneck in Linux TCP.

  13. Development and application of remote video monitoring system for combine harvester based on embedded Linux

    NASA Astrophysics Data System (ADS)

    Chen, Jin; Wang, Yifan; Wang, Xuelei; Wang, Yuehong; Hu, Rui

    2017-01-01

    Combine harvester usually works in sparsely populated areas with harsh environment. In order to achieve the remote real-time video monitoring of the working state of combine harvester. A remote video monitoring system based on ARM11 and embedded Linux is developed. The system uses USB camera for capturing working state video data of the main parts of combine harvester, including the granary, threshing drum, cab and cut table. Using JPEG image compression standard to compress video data then transferring monitoring screen to remote monitoring center over the network for long-range monitoring and management. At the beginning of this paper it describes the necessity of the design of the system. Then it introduces realization methods of hardware and software briefly. And then it describes detailedly the configuration and compilation of embedded Linux operating system and the compiling and transplanting of video server program are elaborated. At the end of the paper, we carried out equipment installation and commissioning on combine harvester and then tested the system and showed the test results. In the experiment testing, the remote video monitoring system for combine harvester can achieve 30fps with the resolution of 800x600, and the response delay in the public network is about 40ms.

  14. Covert Android Rootkit Detection: Evaluating Linux Kernel Level Rootkits on the Android Operating System

    DTIC Science & Technology

    2012-06-14

    System THESIS Robert C. Brodbeck, Civilian, USAF AFIT/GCO/ENG/12- 14 DEPARTMENT OF THE AIR FORCE AIR UNIVERSITY AIR FORCE INSTITUTE OF...the United States. AFIT/GCO/ENG/12- 14 COVERT ANDROID ROOTKIT DETECTION: EVALUATING LINUX KERNEL LEVEL ROOTKITS ON THE ANDROID OPERATING...DISTRIBUTION UNLIMITED AFIT /GCOIEN G/ 12- 14 COVERT ANDROID ROOTKIT DETECTION: EVALUATING LINUX KERNEL LEVEL ROOTKITS ON THE ANDROID OPERATING

  15. The Case for A Hierarchal System Model for Linux Clusters

    SciTech Connect

    Seager, M; Gorda, B

    2009-06-05

    The computer industry today is no longer driven, as it was in the 40s, 50s and 60s, by High-performance computing requirements. Rather, HPC systems, especially Leadership class systems, sit on top of a pyramid investment mode. Figure 1 shows a representative pyramid investment model for systems hardware. At the base of the pyramid is the huge investment (order 10s of Billions of US Dollars per year) in semiconductor fabrication and process technologies. These costs, which are approximately doubling with every generation, are funded from investments multiple markets: enterprise, desktops, games, embedded and specialized devices. Over and above these base technology investments are investments for critical technology elements such as microprocessor, chipsets and memory ASIC components. Investments for these components are spread across the same markets as the base semiconductor processes investments. These second tier investments are approximately half the size of the lower level of the pyramid. The next technology investment layer up, tier 3, is more focused on scalable computing systems such as those needed for HPC and other markets. These tier 3 technology elements include networking (SAN, WAN and LAN), interconnects and large scalable SMP designs. Above these is tier 4 are relatively small investments necessary to build very large, scalable systems high-end or Leadership class systems. Primary among these are the specialized network designs of vertically integrated systems, etc.

  16. Linux and the chemist.

    SciTech Connect

    Moore, J. M.; McCann, M. P.; Materials Science Division; Sam Houston State Univ.

    2003-02-01

    Linux is a freely available computer operating system. Instead of buying multiple copies of the same operating system for use on each computer, Linux may be freely copied onto every computer. Linux distributions come with hundreds of applications, such as compilers, browsers, various servers, graphics software, text editors, and spreadsheets, just to mention a few. Many commercial software companies have ported their applications over to Linux. Numerous programs for chemists, such as statistical treatment, molecular modeling, NMR spectral processing, DNA sequence evaluation, crystal structure solving, and molucular dynamics are available online, many at no cost.

  17. Fractal Weyl law for Linux Kernel architecture

    NASA Astrophysics Data System (ADS)

    Ermann, L.; Chepelianskii, A. D.; Shepelyansky, D. L.

    2011-01-01

    We study the properties of spectrum and eigenstates of the Google matrix of a directed network formed by the procedure calls in the Linux Kernel. Our results obtained for various versions of the Linux Kernel show that the spectrum is characterized by the fractal Weyl law established recently for systems of quantum chaotic scattering and the Perron-Frobenius operators of dynamical maps. The fractal Weyl exponent is found to be ν ≈ 0.65 that corresponds to the fractal dimension of the network d ≈ 1.3. An independent computation of the fractal dimension by the cluster growing method, generalized for directed networks, gives a close value d ≈ 1.4. The eigenmodes of the Google matrix of Linux Kernel are localized on certain principal nodes. We argue that the fractal Weyl law should be generic for directed networks with the fractal dimension d < 2.

  18. Development of a portable Linux-based ECG measurement and monitoring system.

    PubMed

    Tan, Tan-Hsu; Chang, Ching-Su; Huang, Yung-Fa; Chen, Yung-Fu; Lee, Cheng

    2011-08-01

    This work presents a portable Linux-based electrocardiogram (ECG) signals measurement and monitoring system. The proposed system consists of an ECG front end and an embedded Linux platform (ELP). The ECG front end digitizes 12-lead ECG signals acquired from electrodes and then delivers them to the ELP via a universal serial bus (USB) interface for storage, signal processing, and graphic display. The proposed system can be installed anywhere (e.g., offices, homes, healthcare centers and ambulances) to allow people to self-monitor their health conditions at any time. The proposed system also enables remote diagnosis via Internet. Additionally, the system has a 7-in. interactive TFT-LCD touch screen that enables users to execute various functions, such as scaling a single-lead or multiple-lead ECG waveforms. The effectiveness of the proposed system was verified by using a commercial 12-lead ECG signal simulator and in vivo experiments. In addition to its portability, the proposed system is license-free as Linux, an open-source code, is utilized during software development. The cost-effectiveness of the system significantly enhances its practical application for personal healthcare.

  19. Linux thin-client conversion in a large cardiology practice: initial experience.

    PubMed

    Echt, Martin P; Rosen, Jordan

    2004-01-01

    Capital Cardiology Associates (CCA) is a single-specialty cardiology practice with offices in New York and Massachusetts. In 2003, CCA converted its IT system from a Microsoft-based network to a Linux network employing Linux thin-client technology with overall positive outcomes.

  20. Long-Term Operating System Maintenance. A Linux Case Study

    DTIC Science & Technology

    2008-01-01

    when maintaining an operating system for long periods. Therefore, this report serves as an introduction and a simple methodology for performing...and necessary reconfiguration capabilities have been established, an appropriate methodology could be developed for upgrading and updating an...this study proposes a methodology for upgrading and updating an operating system so that installing a newer operating system is not required in order

  1. [Design of an embedded stroke rehabilitation apparatus system based on Linux computer engineering].

    PubMed

    Zhuang, Pengfei; Tian, XueLong; Zhu, Lin

    2014-04-01

    A realizaton project of electrical stimulator aimed at motor dysfunction of stroke is proposed in this paper. Based on neurophysiological biofeedback, this system, using an ARM9 S3C2440 as the core processor, integrates collection and display of surface electromyography (sEMG) signal, as well as neuromuscular electrical stimulation (NMES) into one system. By embedding Linux system, the project is able to use Qt/Embedded as a graphical interface design tool to accomplish the design of stroke rehabilitation apparatus. Experiments showed that this system worked well.

  2. A new design and implementation of an infrared device driver in embedded Linux systems

    NASA Astrophysics Data System (ADS)

    Jia, Li-li; Cui, Hua; Wang, Ru-li

    2009-07-01

    Wireless infrared communication systems are widely-used for the remote controls in portable terminals, particularly for systems requiring low cost, light weight, moderate data rates. They have already proven their electiveness for short-range temporary communications and in high data rate longer range point-to-point systems. This paper proposes the issue of design and implementation of an infrared device driver in a personal portable intelligent digital infrared communications system. After analyzing the various constraints, we use the embedded system based on Samsung S3C2440A 32-bit processor and Linux operating system to design the driver program. The program abandons its traditional Serial interface control mode, uses the generic GPIO to achieve infrared receiver device driver, and intends a user-defined communication protocol which is much more simple and convenient instead of traditional infrared communication protocol to design the character device drivers for the infrared receiver. The communication protocol uses interrupt counter to determine to receive the value and the first code.In this paper, the interrupt handling and an I/O package to reuse Linux device drivers in embedded system is introduced. Via this package, the whole Linux device driver source tree can be reused without any modifications. The driver program can set up and initialize the infrared device, transfer data between the device and the software, configure the device, monitor and trace the status of the device, reset the device, and shut down the device as requested. At last infrared test procedure was prepared and some testing and evaluations were made in a mobile infrared intelligent cicerone system, and the test result shows that the design is simple, practical, with advantages such as easy transplantation, strong reliability and convenience.

  3. Host-Based Systemic Network Obfuscation System for Windows

    DTIC Science & Technology

    2011-06-01

    Linux-based obfuscation tools such as IPLog and Blackhole can implement TCP/IP stack changes similar to IP Personality by changing values of the TCP...Network-Based Host-Based IP Personality Linux / Windows Linux Stealth Patch N/A Linux IPLog N/A Linux Blackhole N/A Linux OSfuscate N/A...Table 2 shows the limitations of each program, particularly the limitations of OSfuscate. OSfuscate, Stealth Patch, IPLog, and Blackhole only

  4. Real-time head movement system and embedded Linux implementation for the control of power wheelchairs.

    PubMed

    Nguyen, H T; King, L M; Knight, G

    2004-01-01

    Mobility has become very important for our quality of life. A loss of mobility due to an injury is usually accompanied by a loss of self-confidence. For many individuals, independent mobility is an important aspect of self-esteem. Head movement is a natural form of pointing and can be used to directly replace the joystick whilst still allowing for similar control. Through the use of embedded LINUX and artificial intelligence, a hands-free head movement wheelchair controller has been designed and implemented successfully. This system provides for severely disabled users an effective power wheelchair control method with improved posture, ease of use and attractiveness.

  5. Use of Low-Cost Acquisition Systems with an Embedded Linux Device for Volcanic Monitoring

    PubMed Central

    Moure, David; Torres, Pedro; Casas, Benito; Toma, Daniel; Blanco, María José; Del Río, Joaquín; Manuel, Antoni

    2015-01-01

    This paper describes the development of a low-cost multiparameter acquisition system for volcanic monitoring that is applicable to gravimetry and geodesy, as well as to the visual monitoring of volcanic activity. The acquisition system was developed using a System on a Chip (SoC) Broadcom BCM2835 Linux operating system (based on DebianTM) that allows for the construction of a complete monitoring system offering multiple possibilities for storage, data-processing, configuration, and the real-time monitoring of volcanic activity. This multiparametric acquisition system was developed with a software environment, as well as with different hardware modules designed for each parameter to be monitored. The device presented here has been used and validated under different scenarios for monitoring ocean tides, ground deformation, and gravity, as well as for monitoring with images the island of Tenerife and ground deformation on the island of El Hierro. PMID:26295394

  6. Use of Low-Cost Acquisition Systems with an Embedded Linux Device for Volcanic Monitoring.

    PubMed

    Moure, David; Torres, Pedro; Casas, Benito; Toma, Daniel; Blanco, María José; Del Río, Joaquín; Manuel, Antoni

    2015-08-19

    This paper describes the development of a low-cost multiparameter acquisition system for volcanic monitoring that is applicable to gravimetry and geodesy, as well as to the visual monitoring of volcanic activity. The acquisition system was developed using a System on a Chip (SoC) Broadcom BCM2835 Linux operating system (based on DebianTM) that allows for the construction of a complete monitoring system offering multiple possibilities for storage, data-processing, configuration, and the real-time monitoring of volcanic activity. This multiparametric acquisition system was developed with a software environment, as well as with different hardware modules designed for each parameter to be monitored. The device presented here has been used and validated under different scenarios for monitoring ocean tides, ground deformation, and gravity, as well as for monitoring with images the island of Tenerife and ground deformation on the island of El Hierro.

  7. Unsteady, Cooled Turbine Simulation Using a PC-Linux Analysis System

    NASA Technical Reports Server (NTRS)

    List, Michael G.; Turner, Mark G.; Chen, Jen-Pimg; Remotigue, Michael G.; Veres, Joseph P.

    2004-01-01

    The fist stage of the high-pressure turbine (HPT) of the GE90 engine was simulated with a three-dimensional unsteady Navier-Sokes solver, MSU Turbo, which uses source terms to simulate the cooling flows. In addition to the solver, its pre-processor, GUMBO, and a post-processing and visualization tool, Turbomachinery Visual3 (TV3) were run in a Linux environment to carry out the simulation and analysis. The solver was run both with and without cooling. The introduction of cooling flow on the blade surfaces, case, and hub and its effects on both rotor-vane interaction as well the effects on the blades themselves were the principle motivations for this study. The studies of the cooling flow show the large amount of unsteadiness in the turbine and the corresponding hot streak migration phenomenon. This research on the GE90 turbomachinery has also led to a procedure for running unsteady, cooled turbine analysis on commodity PC's running the Linux operating system.

  8. A self contained Linux based data acquisition system for 2D detectors with delay line readout

    NASA Astrophysics Data System (ADS)

    Beltran, D.; Toledo, J.; Klora, A. C.; Ramos-Lerate, I.; Martínez, J. C.

    2007-01-01

    This article describes a fast and self-contained data acquisition system for 2D gas-filled detectors with delay line readout. It allows the realization of time resolved experiments in the millisecond scale. The acquisition system comprises of an industrial PC running Linux, a commercial time-to-digital converter and an in-house developed histogramming PCI card. The PC provides a mass storage for images and a graphical user interface for system monitoring and control. The histogramming card builds images with a maximum count rate of 5 MHz limited by the time-to-digital converter. Histograms are transferred to the PC at 85 MB/s. This card also includes a time frame generator, a calibration channel unit and eight digital outputs for experiment control. The control software was developed for easy integration into a beamline, including scans. The system is fully operational at the Spanish beamline BM16 at the ESRF in France, the neutron beamlines Adam and Eva at the ILL in France, the Max Plank Institute in Stuttgart in Germany, the University of Copenhagen in Denmark and at the future ALBA synchrotron in Spain. Some representative collected images from synchrotron and neutron beamlines are presented.

  9. Chandra Science Operational Data System Migration to Linux: Herding Cats through a Funnel

    NASA Astrophysics Data System (ADS)

    Evans, J.; Evans, I.; Fabbiano, G.; Nichols, J.; Paton, L.; Rots, A.

    2014-05-01

    Migration to a new operational system requires technical and non-technical planning to address all of the functional associations affiliated with an established operations environment. The transition to (or addition of) a new platform often includes project planning that has organizational and operational elements. The migration likely tasks individuals both directly and indirectly involved in the project, so identification and coordination of key personnel is essential. The new system must be accurate and robust, and the transition plan typically must ensure that interruptions to services are minimized. Despite detailed integration and testing efforts, back-up plans that include procedures to follow if there are issues during or after installation need to be in place as part of the transition task. In this paper, we present some of the important steps involved in the migration of an operational data system. The management steps include setting objectives and defining scope, identifying stakeholders and establishing communication, assessing the environment and estimating workload, building a schedule, and coordinating with all involved to see it through. We discuss, specifically, the recent migration of the Chandra data system and data center operations from Solaris 32 to Linux 64. The code base is approximately 2 million source lines of code, and supports proposal planning, science mission planning, data processing, and the Chandra data archive. The overall project took approximately 18 months to plan and implement with the resources we had available. Data center operations continued uninterrupted with the exception of a small downtime during the changeover. We highlight our planning and implementation, the experience we gained during the project, and the lessons that we have learned.

  10. Recent advances in PC-Linux systems for electronic structure computations by optimized compilers and numerical libraries.

    PubMed

    Yu, Jen-Shiang K; Yu, Chin-Hui

    2002-01-01

    One of the most frequently used packages for electronic structure research, GAUSSIAN 98, is compiled on Linux systems with various hardware configurations, including AMD Athlon (with the "Thunderbird" core), AthlonMP, and AthlonXP (with the "Palomino" core) systems as well as the Intel Pentium 4 (with the "Willamette" core) machines. The default PGI FORTRAN compiler (pgf77) and the Intel FORTRAN compiler (ifc) are respectively employed with different architectural optimization options to compile GAUSSIAN 98 and test the performance improvement. In addition to the BLAS library included in revision A.11 of this package, the Automatically Tuned Linear Algebra Software (ATLAS) library is linked against the binary executables to improve the performance. Various Hartree-Fock, density-functional theories, and the MP2 calculations are done for benchmarking purposes. It is found that the combination of ifc with ATLAS library gives the best performance for GAUSSIAN 98 on all of these PC-Linux computers, including AMD and Intel CPUs. Even on AMD systems, the Intel FORTRAN compiler invariably produces binaries with better performance than pgf77. The enhancement provided by the ATLAS library is more significant for post-Hartree-Fock calculations. The performance on one single CPU is potentially as good as that on an Alpha 21264A workstation or an SGI supercomputer. The floating-point marks by SpecFP2000 have similar trends to the results of GAUSSIAN 98 package.

  11. SLURM: Simplex Linux Utility for Resource Management

    SciTech Connect

    Jette, M; Grondona, M

    2003-04-22

    Simple Linux Utility for Resource Management (SLURM) is an open source, fault-tolerant, and highly scalable cluster management and job scheduling system for Linux clusters of thousands of nodes. Components include machine status, partition management, job management, scheduling, and stream copy modules. This paper presents an overview of the SLURM architecture and functionality.

  12. SLURM: Simple Linux Utility for Resource Management

    SciTech Connect

    Jette, M; Grondona, M

    2002-12-19

    Simple Linux Utility for Resource Management (SLURM) is an open source, fault-tolerant, and highly scalable cluster management and job scheduling system for Linux clusters of thousands of nodes. Components include machine status, partition management, job management, scheduling and stream copy modules. This paper presents an overview of the SLURM architecture and functionality.

  13. v9fb: a remote framebuffer infrastructure of linux

    SciTech Connect

    Kulkarni, Abhishek; Ionkov, Latchesar

    2008-01-01

    v9fb is a software infrastructure that allows extending framebufFer devices in Linux over the network by providing an abstraction to them in the form of a filesystem hierarchy. Framebuffer based graphic devices export a synthetic filesystem which offers a simple and easy-to-use interface for performing common framebuffer operations. Remote framebuffer devices could be accessed over the network using the 9P protocol support in Linux. We describe the infrastructure in detail and review some of the benefits it offers similar to Plan 9 distributed systems. We discuss the applications of this infrastructure to remotely display and run interactive applications on a terminal while ofFloading the computation to remote servers, and more importantly the flexibility it offers in driving tiled-display walls by aggregating graphic devices in the network.

  14. Managing a Real-Time Embedded Linux Platform with Buildroot

    SciTech Connect

    Diamond, J.; Martin, K.

    2015-01-01

    Developers of real-time embedded software often need to build the operating system, kernel, tools and supporting applications from source to work with the differences in their hardware configuration. The first attempts to introduce Linux-based real-time embedded systems into the Fermilab accelerator controls system used this approach but it was found to be time-consuming, difficult to maintain and difficult to adapt to different hardware configurations. Buildroot is an open source build system with a menu-driven configuration tool (similar to the Linux kernel build system) that automates this process. A customized Buildroot [1] system has been developed for use in the Fermilab accelerator controls system that includes several hardware configuration profiles (including Intel, ARM and PowerPC) and packages for Fermilab support software. A bootable image file is produced containing the Linux kernel, shell and supporting software suite that varies from 3 to 20 megabytes large – ideal for network booting. The result is a platform that is easier to maintain and deploy in diverse hardware configurations

  15. SLURM: Simple Linux Utility for Resource Management

    SciTech Connect

    Jette, M; Dunlap, C; Garlick, J; Grondona, M

    2002-07-08

    Simple Linux Utility for Resource Management (SLURM) is an open source, fault-tolerant, and highly scalable cluster management and job scheduling system for Linux clusters of thousands of nodes. Components include machine status, partition management, job management, scheduling and stream copy modules. The design also includes a scalable, general-purpose communication infrastructure. This paper presents a overview of the SLURM architecture and functionality.

  16. A Taxonomy of Software Deceptive Interpretation in the Linux Operating System

    DTIC Science & Technology

    2007-11-02

    microcode on both Intel and AMD processors can be patched through software updates [ 14 , 15]. Theoretically, CPU instructions could be altered directly to...Series 2(42). 14 . Anonymous, Opteron Exposed: Reverse Engineering AMD K8 Microcode Updates. http://www.packetstormsecurity.nl/0407-exploits...public release; distribution is unlimited. 13. SUPPLEMENTARY NOTES 14 . ABSTRACT Rootkits are malicious tools installed on compromised computer systems

  17. Abstract of talk for Silicon Valley Linux Users Group

    NASA Technical Reports Server (NTRS)

    Clanton, Sam

    2003-01-01

    The use of Linux for research at NASA Ames is discussed.Topics include:work with the Atmospheric Physics branch on software for a spectrometer to be used in the CRYSTAL-FACE mission this summer; work on in the Neuroengineering Lab with code IC including an introduction to the extension of the human senses project,advantages with using linux for real-time biological data processing,algorithms utilized on a linux system, goals of the project,slides of people with Neuroscan caps on, and progress that has been made and how linux has helped.

  18. KNBD: A Remote Kernel Block Server for Linux

    NASA Technical Reports Server (NTRS)

    Becker, Jeff

    1999-01-01

    I am developing a prototype of a Linux remote disk block server whose purpose is to serve as a lower level component of a parallel file system. Parallel file systems are an important component of high performance supercomputers and clusters. Although supercomputer vendors such as SGI and IBM have their own custom solutions, there has been a void and hence a demand for such a system on Beowulf-type PC Clusters. Recently, the Parallel Virtual File System (PVFS) project at Clemson University has begun to address this need (1). Although their system provides much of the functionality of (and indeed was inspired by) the equivalent file systems in the commercial supercomputer market, their system is all in user-space. Migrating their 10 services to the kernel could provide a performance boost, by obviating the need for expensive system calls. Thanks to Pavel Machek, the Linux kernel has provided the network block device (2) with kernels 2.1.101 and later. You can configure this block device to redirect reads and writes to a remote machine's disk. This can be used as a building block for constructing a striped file system across several nodes.

  19. BSD Portals for LINUX 2.0

    NASA Technical Reports Server (NTRS)

    McNab, A. David; woo, Alex (Technical Monitor)

    1999-01-01

    Portals, an experimental feature of 4.4BSD, extend the file system name space by exporting certain open () requests to a user-space daemon. A portal daemon is mounted into the file name space as if it were a standard file system. When the kernel resolves a pathname and encounters a portal mount point, the remainder of the path is passed to the portal daemon. Depending on the portal "pathname" and the daemon's configuration, some type of open (2) is performed. The resulting file descriptor is passed back to the kernel which eventually returns it to the user, to whom it appears that a "normal" open has occurred. A proxy portalfs file system is responsible for kernel interaction with the daemon. The overall effect is that the portal daemon performs an open (2) on behalf of the kernel, possibly hiding substantial complexity from the calling process. One particularly useful application is implementing a connection service that allows simple scripts to open network sockets. This paper describes the implementation of portals for LINUX 2.0.

  20. Real-time data collection in Linux: a case study.

    PubMed

    Finney, S A

    2001-05-01

    Multiuser UNIX-like operating systems such as Linux are often considered unsuitable for real-time data collection because of the potential for indeterminate timing latencies resulting from preemptive scheduling. In this paper, Linux is shown to be fully adequate for precisely controlled programming with millisecond resolution or better. The Linux system calls that subserve such timing control are described and tested and then utilized in a MIDI-based program for tapping and music performance experiments. The timing of this program, including data input and output, is shown to be accurate at the millisecond level. This demonstrates that Linux, with proper programming, is suitable for real-time experiment software. In addition, the detailed description and test of both the operating system facilities and the application program itself may serve as a model for publicly documenting programming methods and software performance on other operating systems.

  1. Kernel-based Linux emulation for Plan 9.

    SciTech Connect

    Minnich, Ronald G.

    2010-09-01

    CNKemu is a kernel-based system for the 9k variant of the Plan 9 kernel. It is designed to provide transparent binary support for programs compiled for IBM's Compute Node Kernel (CNK) on the Blue Gene series of supercomputers. This support allows users to build applications with the standard Blue Gene toolchain, including C++ and Fortran compilers. While the CNK is not Linux, IBM designed the CNK so that the user interface has much in common with the Linux 2.0 system call interface. The Plan 9 CNK emulator hence provides the foundation of kernel-based Linux system call support on Plan 9. In this paper we discuss cnkemu's implementation and some of its more interesting features, such as the ability to easily intermix Plan 9 and Linux system calls.

  2. SLURM: Simple Linux Utility for Resource Management

    SciTech Connect

    Jette, M; Dunlap, C; Garlick, J; Grondona, M

    2002-04-24

    Simple Linux Utility for Resource Management (SLURM) is an open source, fault-tolerant, and highly scalable cluster management and job scheduling system for Linux clusters of thousands of nodes. Components include machine status, partition management, job management, and scheduling modules. The design also includes a scalable, general-purpose communication infrastructure. Development will take place in four phases: Phase I results in a solid infrastructure; Phase II produces a functional but limited interactive job initiation capability without use of the interconnect/switch; Phase III provides switch support and documentation; Phase IV provides job status, fault-tolerance, and job queuing and control through Livermore's Distributed Production Control System (DPCS), a meta-batch and resource management system.

  3. Building the World's Fastest Linux Cluster

    SciTech Connect

    Goldstone, R; Seager, M

    2003-10-24

    Imagine having 2,304 Xeon processors running day and night solving complex problems. With a theoretical peak of 11.2 teraflops, that is just what the MCR cluster at Lawrence Livermore National Labs (LLNL) is doing. Over the past several years, Lawrence Livermore National Laboratory has deployed a series of increasingly large and powerful Intel-based Linux clusters. The most significant of these is a cluster known as the MCR (Multiprogrammactic Capability Resource). With 1,152 Intel Xeon (2.4 GHz) dual-processor nodes from Linux NetworX and a high performance interconnect from Quadrics, LTD., the MCR currently ranks third on the 21st Top 500 Supercomputer Sites List and is the fastest Linux cluster in the world. This feat was accomplished with a total system cost (hardware including maintenance, in-reconnect, global file system storage) of under $14 million. Although production clusters like the MCR are still custom built supercomputers that require as much artistry as skill, the experiences of LLNL have helped clear an important path for other clusters to follow.

  4. Firewall using Red Hat Linux 8.0

    NASA Astrophysics Data System (ADS)

    Ganguly, Pallab

    2006-10-01

    Due to the excessive amount of security threats, the need of a firewall is felt. Again, this firewall also acts as a proxy server to talk to the Internet. Any internal network can be masqueraded against the external world through this firewall. In case of different TCP/IP services like smtp, snmp, udp, tcp, http, and https, it can be restricted userwise. This firewall uses the Squid.conf configuration file as well as PAM (Password Authentication Module), the html files and other configuration files of the Linux operating system. The web browser used is Mozilla. Some CGI/PERL scripts are used. Different Intranet services are also provided userwise and mentioned in the squid.conf file. The major finding in this paper is the simplified way to create a security firewall.

  5. A General Purpose High Performance Linux Installation Infrastructure

    SciTech Connect

    Wachsmann, Alf

    2002-06-17

    With more and more and larger and larger Linux clusters, the question arises how to install them. This paper addresses this question by proposing a solution using only standard software components. This installation infrastructure scales well for a large number of nodes. It is also usable for installing desktop machines or diskless Linux clients, thus, is not designed for cluster installations in particular but is, nevertheless, highly performant. The infrastructure proposed uses PXE as the network boot component on the nodes. It uses DHCP and TFTP servers to get IP addresses and a bootloader to all nodes. It then uses kickstart to install Red Hat Linux over NFS. We have implemented this installation infrastructure at SLAC with our given server hardware and installed a 256 node cluster in 30 minutes. This paper presents the measurements from this installation and discusses the bottlenecks in our installation.

  6. Network systems security analysis

    NASA Astrophysics Data System (ADS)

    Yilmaz, Ä.°smail

    2015-05-01

    Network Systems Security Analysis has utmost importance in today's world. Many companies, like banks which give priority to data management, test their own data security systems with "Penetration Tests" by time to time. In this context, companies must also test their own network/server systems and take precautions, as the data security draws attention. Based on this idea, the study cyber-attacks are researched throughoutly and Penetration Test technics are examined. With these information on, classification is made for the cyber-attacks and later network systems' security is tested systematically. After the testing period, all data is reported and filed for future reference. Consequently, it is found out that human beings are the weakest circle of the chain and simple mistakes may unintentionally cause huge problems. Thus, it is clear that some precautions must be taken to avoid such threats like updating the security software.

  7. Achieving Order through CHAOS: the LLNL HPC Linux Cluster Experience

    SciTech Connect

    Braby, R L; Garlick, J E; Goldstone, R J

    2003-05-02

    Since fall 2001, Livermore Computing at Lawrence Livermore National Laboratory has deployed 11 Intel IA-32-based Linux clusters ranging in size up to 1154 nodes. All provide a common programming model and implement a similar cluster architecture. Hardware components are carefully selected for performance, usability, manageability, and reliability and are then integrated and supported using a strategy that evolved from practical experience. Livermore Computing Linux clusters run a common software environment that is developed and maintained in-house while drawing components and additional support from the open source community and industrial partnerships. The environment is based on Red Hat Linux and adds kernel modifications, cluster system management, monitoring and failure detection, resource management, authentication and access control, development environment, and parallel file system. The overall strategy has been successful and demonstrates that world-class high-performance computing resources can be built and maintained using commodity off-the-shelf hardware and open source software.

  8. Software structure for broadband wireless sensor network system

    NASA Astrophysics Data System (ADS)

    Kwon, Hyeokjun; Oh, Sechang; Yoon, Hargsoon; Varadan, Vijay K.

    2010-04-01

    Zigbee Sensor Network system has been investigating for monitoring and analyzing the data measured from a lot of sensors because the Zigbee Sensor Network has several advantages of low power consumption, compact size, and multi-node connection. However, it has a disadvantage not to be able to monitor the data measured from sensors at the remote area such as other room that is located at other city. This paper describes the software structure to compensate the defect with combining the Zigbee Sensor Network and wireless LAN technology for remote monitoring of measured sensor data. The software structure has both benefits of Zigbee Sensor Network and the advantage of wireless LAN. The software structure has three main software structures. The first software structure consists of the function in order to acquire the data from sensors and the second software structure is to gather the sensor data through wireless Zigbee and to send the data to Monitoring system by using wireless LAN. The second part consists of Linux packages software based on 2440 CPU (Samsung corp.), which has ARM9 core. The Linux packages include bootloader, device drivers, kernel, and applications, and the applications are TCP/IP server program, the program interfacing with Zigbee RF module, and wireless LAN program. The last part of software structure is to receive the sensor data through TCP/IP client program from Wireless Gate Unit and to display graphically measured data by using MATLAB program; the sensor data is measured on 100Hz sampling rate and the measured data has 10bit data resolution. The wireless data transmission rate per each channel is 1.6kbps.

  9. The network queueing system

    NASA Technical Reports Server (NTRS)

    Kingsbury, Brent K.

    1986-01-01

    Described is the implementation of a networked, UNIX based queueing system developed on contract for NASA. The system discussed supports both batch and device requests, and provides the facilities of remote queueing, request routing, remote status, queue access controls, batch request resource quota limits, and remote output return.

  10. Generating Computer Forensic Super Timelines under Linux: A Comprehensive Guide for Windows-based Disk Images

    DTIC Science & Technology

    2011-10-01

    available Linux, BSD and Solaris distributions...the same for non-Windows optical discs including those used for the installation of UNIX-based operating systems such as Solaris and Linux. While...data files capabilities are combined with The Sleuth Kit’s filesystem date/time metadata support, a powerful toolset becomes available to the digital

  11. Universal Network Access System

    DTIC Science & Technology

    2003-11-01

    successfully carried out, however. A multirate and multiprotocol system , based on software configurable, hardware accelerated processing engines has...network interface. The system will support filtering and extracting packets or cells for QoS measurements using filtering criteria, which may be...integrated designs. 6.5 Summary The intent of the research has been successfully carried out. A multirate and multiprotocol system , based on software

  12. Scalability and Performance of a Large Linux Cluster

    SciTech Connect

    BRIGHTWELL,RONALD B.; PLIMPTON,STEVEN J.

    2000-01-20

    In this paper the authors present performance results from several parallel benchmarks and applications on a 400-node Linux cluster at Sandia National Laboratories. They compare the results on the Linux cluster to performance obtained on a traditional distributed-memory massively parallel processing machine, the Intel TeraFLOPS. They discuss the characteristics of these machines that influence the performance results and identify the key components of the system software that they feel are important to allow for scalability of commodity-based PC clusters to hundreds and possibly thousands of processors.

  13. A dynamic kernel modifier for linux

    SciTech Connect

    Minnich, R. G.

    2002-09-03

    Dynamic Kernel Modifier, or DKM, is a kernel module for Linux that allows user-mode programs to modify the execution of functions in the kernel without recompiling or modifying the kernel source in any way. Functions may be traced, either function entry only or function entry and exit; nullified; or replaced with some other function. For the tracing case, function execution results in the activation of a watchpoint. When the watchpoint is activated, the address of the function is logged in a FIFO buffer that is readable by external applications. The watchpoints are time-stamped with the resolution of the processor high resolution timers, which on most modem processors are accurate to a single processor tick. DKM is very similar to earlier systems such as the SunOS trace device or Linux TT. Unlike these two systems, and other similar systems, DKM requires no kernel modifications. DKM allows users to do initial probing of the kernel to look for performance problems, or even to resolve potential problems by turning functions off or replacing them. DKM watchpoints are not without cost: it takes about 200 nanoseconds to make a log entry on an 800 Mhz Pentium-Ill. The overhead numbers are actually competitive with other hardware-based trace systems, although it has less 'Los Alamos National Laboratory is operated by the University of California for the National Nuclear Security Administration of the United States Department of Energy under contract W-7405-ENG-36. accuracy than an In-Circuit Emulator such as the American Arium. Once the user has zeroed in on a problem, other mechanisms with a higher degree of accuracy can be used.

  14. Distributed System Intruder Tools, Trinoo and Tribe Flood Network

    SciTech Connect

    Criscuolo, P.J.; Rathbun, T

    1999-12-21

    Trinoo and Tribe Flood Network (TFN) are new forms of denial of Service (DOS) attacks. attacks are designed to bring down a computer or network by overloading it with a large amount of network traffic using TCP, UDP, or ICMP. In the past, these attacks came from a single location and were easy to detect. Trinoo and TFN are distributed system intruder tools. These tools launch DoS attacks from multiple computer systems at a target system simultaneously. This makes the assault hard to detect and almost impossible to track to the original attacker. Because these attacks can be launched from hundreds of computers under the command of a single attacker, they are far more dangerous than any DoS attack launched from a single location. These distributed tools have only been seen on Solaris and Linux machines, but there is no reason why they could not be modified for UNIX machines. The target system can also be of any type because the attack is based on the TCP/IP architecture, not a flaw in any particular operating system (OS). CIAC considers the risks presented by these DoS tools to be high.

  15. Physiological Networks: towards systems physiology

    NASA Astrophysics Data System (ADS)

    Bartsch, Ronny P.; Bashan, Amir; Kantelhardt, Jan W.; Havlin, Shlomo; Ivanov, Plamen Ch.

    2012-02-01

    The human organism is an integrated network where complex physiologic systems, each with its own regulatory mechanisms, continuously interact, and where failure of one system can trigger a breakdown of the entire network. Identifying and quantifying dynamical networks of diverse systems with different types of interactions is a challenge. Here, we develop a framework to probe interactions among diverse systems, and we identify a physiologic network. We find that each physiologic state is characterized by a specific network structure, demonstrating a robust interplay between network topology and function. Across physiologic states the network undergoes topological transitions associated with fast reorganization of physiologic interactions on time scales of a few minutes, indicating high network flexibility in response to perturbations. The proposed system-wide integrative approach may facilitate new dimensions to the field of systems physiology.

  16. Transitioning to Intel-based Linux Servers in the Payload Operations Integration Center

    NASA Technical Reports Server (NTRS)

    Guillebeau, P. L.

    2004-01-01

    The MSFC Payload Operations Integration Center (POIC) is the focal point for International Space Station (ISS) payload operations. The POIC contains the facilities, hardware, software and communication interface necessary to support payload operations. ISS ground system support for processing and display of real-time spacecraft and telemetry and command data has been operational for several years. The hardware components were reaching end of life and vendor costs were increasing while ISS budgets were becoming severely constrained. Therefore it has been necessary to migrate the Unix portions of our ground systems to commodity priced Intel-based Linux servers. hardware architecture including networks, data storage, and highly available resources. This paper will concentrate on the Linux migration implementation for the software portion of our ground system. The migration began with 3.5 million lines of code running on Unix platforms with separate servers for telemetry, command, Payload information management systems, web, system control, remote server interface and databases. The Intel-based system is scheduled to be available for initial operational use by August 2004 The overall migration to Intel-based Linux servers in the control center involves changes to the This paper will address the Linux migration study approach including the proof of concept, criticality of customer buy-in and importance of beginning with POSlX compliant code. It will focus on the development approach explaining the software lifecycle. Other aspects of development will be covered including phased implementation, interim milestones and metrics measurements and reporting mechanisms. This paper will also address the testing approach covering all levels of testing including development, development integration, IV&V, user beta testing and acceptance testing. Test results including performance numbers compared with Unix servers will be included. need for a smooth transition while maintaining

  17. Networked differential GPS system

    NASA Technical Reports Server (NTRS)

    Mueller, K. Tysen (Inventor); Loomis, Peter V. W. (Inventor); Kalafus, Rudolph M. (Inventor); Sheynblat, Leonid (Inventor)

    1994-01-01

    An embodiment of the present invention relates to a worldwide network of differential GPS reference stations (NDGPS) that continually track the entire GPS satellite constellation and provide interpolations of reference station corrections tailored for particular user locations between the reference stations Each reference station takes real-time ionospheric measurements with codeless cross-correlating dual-frequency carrier GPS receivers and computes real-time orbit ephemerides independently. An absolute pseudorange correction (PRC) is defined for each satellite as a function of a particular user's location. A map of the function is constructed, with iso-PRC contours. The network measures the PRCs at a few points, so-called reference stations and constructs an iso-PRC map for each satellite. Corrections are interpolated for each user's site on a subscription basis. The data bandwidths are kept to a minimum by transmitting information that cannot be obtained directly by the user and by updating information by classes and according to how quickly each class of data goes stale given the realities of the GPS system. Sub-decimeter-level kinematic accuracy over a given area is accomplished by establishing a mini-fiducial network.

  18. Network Systems Administration Needs Assessment.

    ERIC Educational Resources Information Center

    Lexington Community Coll., KY. Office of Institutional Research.

    In spring 1996, Lexington Community College (LCC) in Kentucky, conducted a survey to gather information on employment trends and educational needs in the field of network systems administration (NSA). NSA duties involve the installation and administration of network operating systems, applications software, and networking infrastructure;…

  19. Network of Networks and the Climate System

    NASA Astrophysics Data System (ADS)

    Kurths, Jürgen; Boers, Niklas; Bookhagen, Bodo; Donges, Jonathan; Donner, Reik; Malik, Nishant; Marwan, Norbert; Stolbova, Veronika

    2013-04-01

    Network of networks is a new direction in complex systems science. One can find such networks in various fields, such as infrastructure (power grids etc.), human brain or Earth system. Basic properties and new characteristics, such as cross-degree, or cross-betweenness will be discussed. This allows us to quantify the structural role of single vertices or whole sub-networks with respect to the interaction of a pair of subnetworks on local, mesoscopic, and global topological scales. Next, we consider an inverse problem: Is there a backbone-like structure underlying the climate system? For this we propose a method to reconstruct and analyze a complex network from data generated by a spatio-temporal dynamical system. This technique is then applied to 3-dimensional data of the climate system. We interpret different heights in the atmosphere as different networks and the whole as a network of networks. This approach enables us to uncover relations to global circulation patterns in oceans and atmosphere. The global scale view on climate networks offers promising new perspectives for detecting dynamical structures based on nonlinear physical processes in the climate system. This concept is applied to Indian Monsoon data in order to characterize the regional occurrence of strong rain events and its impact on predictability. References: Arenas, A., A. Diaz-Guilera, J. Kurths, Y. Moreno, and C. Zhou, Phys. Reports 2008, 469, 93. Donges, J., Y. Zou, N. Marwan, and J. Kurths, Europhys. Lett. 2009, 87, 48007. Donner, R., Y. Zou, J. Donges, N. Marwan, and J. Kurths, Phys. Rev. E 2010, 81, 015101(R ). Mokhov, I. I., D. A. Smirnov, P. I. Nakonechny, S. S. Kozlenko, E. P. Seleznev, and J. Kurths, Geophys. Res. Lett. 2011, 38, L00F04. Malik, N., B. Bookhagen, N. Marwan, and J. Kurths, Climate Dynamics, 2012, 39, 971. Donges, J., H. Schultz, N. Marwan, Y. Zou, J. Kurths, Eur. J. Phys. B 2011, 84, 635-651. Donges, J., R. Donner, M. Trauth, N. Marwan, H.J. Schellnhuber, and J. Kurths

  20. Views of wireless network systems.

    SciTech Connect

    Young, William Frederick; Duggan, David Patrick

    2003-10-01

    Wireless networking is becoming a common element of industrial, corporate, and home networks. Commercial wireless network systems have become reliable, while the cost of these solutions has become more affordable than equivalent wired network solutions. The security risks of wireless systems are higher than wired and have not been studied in depth. This report starts to bring together information on wireless architectures and their connection to wired networks. We detail information contained on the many different views of a wireless network system. The method of using multiple views of a system to assist in the determination of vulnerabilities comes from the Information Design Assurance Red Team (IDART{trademark}) Methodology of system analysis developed at Sandia National Laboratories.

  1. [Network structures in biological systems].

    PubMed

    Oleskin, A V

    2013-01-01

    Network structures (networks) that have been extensively studied in the humanities are characterized by cohesion, a lack of a central control unit, and predominantly fractal properties. They are contrasted with structures that contain a single centre (hierarchies) as well as with those whose elements predominantly compete with one another (market-type structures). As far as biological systems are concerned, their network structures can be subdivided into a number of types involving different organizational mechanisms. Network organization is characteristic of various structural levels of biological systems ranging from single cells to integrated societies. These networks can be classified into two main subgroups: (i) flat (leaderless) network structures typical of systems that are composed of uniform elements and represent modular organisms or at least possess manifest integral properties and (ii) three-dimensional, partly hierarchical structures characterized by significant individual and/or intergroup (intercaste) differences between their elements. All network structures include an element that performs structural, protective, and communication-promoting functions. By analogy to cell structures, this element is denoted as the matrix of a network structure. The matrix includes a material and an immaterial component. The material component comprises various structures that belong to the whole structure and not to any of its elements per se. The immaterial (ideal) component of the matrix includes social norms and rules regulating network elements' behavior. These behavioral rules can be described in terms of algorithms. Algorithmization enables modeling the behavior of various network structures, particularly of neuron networks and their artificial analogs.

  2. Language Networks as Complex Systems

    ERIC Educational Resources Information Center

    Lee, Max Kueiming; Ou, Sheue-Jen

    2008-01-01

    Starting in the late eighties, with a growing discontent with analytical methods in science and the growing power of computers, researchers began to study complex systems such as living organisms, evolution of genes, biological systems, brain neural networks, epidemics, ecology, economy, social networks, etc. In the early nineties, the research…

  3. Networking Systems and Equipment.

    ERIC Educational Resources Information Center

    Kranz, Maciej

    2002-01-01

    Describes how high-bandwidth networks are delivering new educational and administrative opportunities for K-12 school districts. Addresses implementing the new network, upgrading to a switched environment, adding intelligent switches, IP telephony, and wireless technology. Describes deployment and benefits of broadband in the Denver public schools…

  4. A package of Linux scripts for the parallelization of Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Badal, Andreu; Sempau, Josep

    2006-09-01

    also provided. Typical running time:The execution time of each script largely depends on the number of computers that are used, the actions that are to be performed and, to a lesser extent, on the network connexion bandwidth. Unusual features of the program:Any computer on the Internet with a Secure Shell client/server program installed can be used as a node of a virtual computer cluster for parallel calculations with the sequential source code. The simplicity of the parallelization scheme makes the use of this package a straightforward task, which does not require installing any additional libraries. Program summary 2Title of program:seedsMLCG Catalogue identifier:ADYE_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADYE_v1_0 Program obtainable from:CPC Program Library, Queen's University of Belfast, Northern Ireland Computer for which the program is designed and others in which it is operable:Any computer with a FORTRAN compiler Operating systems under which the program has been tested:Linux (RedHat 8.0, SuSe 8.1, Debian Woody 3.1), MS Windows (2000, XP) Compilers:GNU FORTRAN g77 (Linux and Windows); g95 (Linux); Intel Fortran Compiler 7.1 (Linux); Compaq Visual Fortran 6.1 (Windows) Programming language used:FORTRAN 77 No. of bits in a word:32 Memory required to execute with typical data:500 kilobytes No. of lines in distributed program, including test data, etc.:492 No. of bytes in distributed program, including test data, etc.:5582 Distribution format:tar.gz Nature of the physical problem:Statistically independent results from different runs of a Monte Carlo code can be obtained using uncorrelated sequences of random numbers on each execution. Multiplicative linear congruential generators (MLCG), or other generators that are based on them such as RANECU, can be adapted to produce these sequences. Method of solution:For a given MLCG, the presented program calculates initialization values that produce disjoint, consecutive sequences of pseudo

  5. Climate tools in mainstream Linux distributions

    NASA Astrophysics Data System (ADS)

    McKinstry, Alastair

    2015-04-01

    Debian/meterology is a project to integrate climate tools and analysis software into the mainstream Debian/Ubuntu Linux distributions. This work describes lessons learnt, and recommends practices for scientific software to be adopted and maintained in OS distributions. In addition to standard analysis tools (cdo,, grads, ferret, metview, ncl, etc.), software used by the Earth System Grid Federation was chosen for integraion, to enable ESGF portals to be built on this base; however exposing scientific codes via web APIs enables security weaknesses, normally ignorable, to be exposed. How tools are hardened, and what changes are required to handle security upgrades, are described. Secondly, to enable libraries and components (e.g. Python modules) to be integrated requires planning by writers: it is not sufficient to assume users can upgrade their code when you make incompatible changes. Here, practices are recommended to enable upgrades and co-installability of C, C++, Fortran and Python codes. Finally, software packages such as NetCDF and HDF5 can be built in multiple configurations. Tools may then expect incompatible versions of these libraries (e.g. serial and parallel) to be simultaneously available; how this was solved in Debian using "pkg-config" and shared library interfaces is described, and best practices for software writers to enable this are summarised.

  6. Computation and Communication Evaluation of an Authentication Mechanism for Time-Triggered Networked Control Systems.

    PubMed

    Martins, Goncalo; Moondra, Arul; Dubey, Abhishek; Bhattacharjee, Anirban; Koutsoukos, Xenofon D

    2016-07-25

    In modern networked control applications, confidentiality and integrity are important features to address in order to prevent against attacks. Moreover, network control systems are a fundamental part of the communication components of current cyber-physical systems (e.g., automotive communications). Many networked control systems employ Time-Triggered (TT) architectures that provide mechanisms enabling the exchange of precise and synchronous messages. TT systems have computation and communication constraints, and with the aim to enable secure communications in the network, it is important to evaluate the computational and communication overhead of implementing secure communication mechanisms. This paper presents a comprehensive analysis and evaluation of the effects of adding a Hash-based Message Authentication (HMAC) to TT networked control systems. The contributions of the paper include (1) the analysis and experimental validation of the communication overhead, as well as a scalability analysis that utilizes the experimental result for both wired and wireless platforms and (2) an experimental evaluation of the computational overhead of HMAC based on a kernel-level Linux implementation. An automotive application is used as an example, and the results show that it is feasible to implement a secure communication mechanism without interfering with the existing automotive controller execution times. The methods and results of the paper can be used for evaluating the performance impact of security mechanisms and, thus, for the design of secure wired and wireless TT networked control systems.

  7. Computation and Communication Evaluation of an Authentication Mechanism for Time-Triggered Networked Control Systems

    PubMed Central

    Martins, Goncalo; Moondra, Arul; Dubey, Abhishek; Bhattacharjee, Anirban; Koutsoukos, Xenofon D.

    2016-01-01

    In modern networked control applications, confidentiality and integrity are important features to address in order to prevent against attacks. Moreover, network control systems are a fundamental part of the communication components of current cyber-physical systems (e.g., automotive communications). Many networked control systems employ Time-Triggered (TT) architectures that provide mechanisms enabling the exchange of precise and synchronous messages. TT systems have computation and communication constraints, and with the aim to enable secure communications in the network, it is important to evaluate the computational and communication overhead of implementing secure communication mechanisms. This paper presents a comprehensive analysis and evaluation of the effects of adding a Hash-based Message Authentication (HMAC) to TT networked control systems. The contributions of the paper include (1) the analysis and experimental validation of the communication overhead, as well as a scalability analysis that utilizes the experimental result for both wired and wireless platforms and (2) an experimental evaluation of the computational overhead of HMAC based on a kernel-level Linux implementation. An automotive application is used as an example, and the results show that it is feasible to implement a secure communication mechanism without interfering with the existing automotive controller execution times. The methods and results of the paper can be used for evaluating the performance impact of security mechanisms and, thus, for the design of secure wired and wireless TT networked control systems. PMID:27463718

  8. Artificial Neural Network Analysis System

    DTIC Science & Technology

    2007-11-02

    Target detection, multi-target tracking and threat identification of ICBM and its warheads by sensor fusion and data fusion of sensors in a fuzzy neural network system based on the compound eye of a fly.

  9. Lightweight Corefile Library for Linux

    SciTech Connect

    2007-09-22

    Liblwcf attempts to generate stack traces from failing processes as opposed to dumping full corefiles. This can be beneficial when running large parallel applications where dumping f a fully memory image could flood network filesystem servers.

  10. The Design of NetSecLab: A Small Competition-Based Network Security Lab

    ERIC Educational Resources Information Center

    Lee, C. P.; Uluagac, A. S.; Fairbanks, K. D.; Copeland, J. A.

    2011-01-01

    This paper describes a competition-style of exercise to teach system and network security and to reinforce themes taught in class. The exercise, called NetSecLab, is conducted on a closed network with student-formed teams, each with their own Linux system to defend and from which to launch attacks. Students are expected to learn how to: 1) install…

  11. Coalition Network Management System

    DTIC Science & Technology

    2008-02-01

    adopted PECC architecture will integrate mechanisms for resource management through the use of Semantically Augmented Resource Managers ( SARM ). The...goal is to provide minimally intrusive resource management, using as few windows as possible. SARM will allow a network manager to focus on the...tasks specific to each individual operator using one-glance awareness of task availability and caution panel style indicators. SARM will provide a

  12. Multilevel Complex Networks and Systems

    NASA Astrophysics Data System (ADS)

    Caldarelli, Guido

    2014-03-01

    Network theory has been a powerful tool to model isolated complex systems. However, the classical approach does not take into account the interactions often present among different systems. Hence, the scientific community is nowadays concentrating the efforts on the foundations of new mathematical tools for understanding what happens when multiple networks interact. The case of economic and financial networks represents a paramount example of multilevel networks. In the case of trade, trade among countries the different levels can be described by the different granularity of the trading relations. Indeed, we have now data from the scale of consumers to that of the country level. In the case of financial institutions, we have a variety of levels at the same scale. For example one bank can appear in the interbank networks, ownership network and cds networks in which the same institution can take place. In both cases the systemically important vertices need to be determined by different procedures of centrality definition and community detection. In this talk I will present some specific cases of study related to these topics and present the regularities found. Acknowledged support from EU FET Project ``Multiplex'' 317532.

  13. Linux Incident Response Volatile Data Analysis Framework

    ERIC Educational Resources Information Center

    McFadden, Matthew

    2013-01-01

    Cyber incident response is an emphasized subject area in cybersecurity in information technology with increased need for the protection of data. Due to ongoing threats, cybersecurity imposes many challenges and requires new investigative response techniques. In this study a Linux Incident Response Framework is designed for collecting volatile data…

  14. Millisecond accuracy video display using OpenGL under Linux.

    PubMed

    Stewart, Neil

    2006-02-01

    To measure people's reaction times to the nearest millisecond, it is necessary to know exactly when a stimulus is displayed. This article describes how to display stimuli with millisecond accuracy on a normal CRT monitor, using a PC running Linux. A simple C program is presented to illustrate how this may be done within X Windows using the OpenGL rendering system. A test of this system is reported that demonstrates that stimuli may be consistently displayed with millisecond accuracy. An algorithm is presented that allows the exact time of stimulus presentation to be deduced, even if there are relatively large errors in measuring the display time.

  15. Image Capture and Display Based on Embedded Linux

    NASA Astrophysics Data System (ADS)

    Weigong, Zhang; Suran, Di; Yongxiang, Zhang; Liming, Li

    For the requirement of building a highly reliable communication system, SpaceWire was selected in the integrated electronic system. There was a need to test the performance of SpaceWire. As part of the testing work, the goal of this paper is to transmit image data from CMOS camera through SpaceWire and display real-time images on the graphical user interface with Qt in the embedded development platform of Linux & ARM. A point-to-point mode of transmission was chosen; the running result showed the two communication ends basically reach a consensus picture in succession. It suggests that the SpaceWire can transmit the data reliably.

  16. Wireless nanosensor network system

    NASA Astrophysics Data System (ADS)

    Oh, Sechang; Kwon, Hyukjun; Kegley, Lauren; Yoon, Hargsoon; Varadan, Vijay K.

    2009-03-01

    Many types of wireless modules are being developed to enhance wireless performance with low power consumption, compact size, high data rates, and wide range coverage. However trade-offs must be taken into consideration in order to satisfy all aspects of wireless performance. For example, in order to increase the data rate and wide range coverage, power consumption should be sacrificed. To overcome these drawbacks, the paper presents a wireless client module which offers low power consumption along with a wireless receiver module that has the strength to provide high data rates and wide range coverage. Adopting Zigbee protocol in the wireless client module, the power consumption performance is enhanced so that it plays a part of the mobile device. On the other hand, the wireless receiver module, as adopting Zigbee and Wi-Fi protocol, provides high data rate, wide range coverage, and easy connection to the existing Internet network so that it plays a part of the portable device. This module demonstrates monitoring of gait analysis. The results show that the sensing data being measured can be monitored in any remote place with access to the Internet network.

  17. Promoting Social Network Awareness: A Social Network Monitoring System

    ERIC Educational Resources Information Center

    Cadima, Rita; Ferreira, Carlos; Monguet, Josep; Ojeda, Jordi; Fernandez, Joaquin

    2010-01-01

    To increase communication and collaboration opportunities, members of a community must be aware of the social networks that exist within that community. This paper describes a social network monitoring system--the KIWI system--that enables users to register their interactions and visualize their social networks. The system was implemented in a…

  18. Network dynamics and systems biology

    NASA Astrophysics Data System (ADS)

    Norrell, Johannes A.

    The physics of complex systems has grown considerably as a field in recent decades, largely due to improved computational technology and increased availability of systems level data. One area in which physics is of growing relevance is molecular biology. A new field, systems biology, investigates features of biological systems as a whole, a strategy of particular importance for understanding emergent properties that result from a complex network of interactions. Due to the complicated nature of the systems under study, the physics of complex systems has a significant role to play in elucidating the collective behavior. In this dissertation, we explore three problems in the physics of complex systems, motivated in part by systems biology. The first of these concerns the applicability of Boolean models as an approximation of continuous systems. Studies of gene regulatory networks have employed both continuous and Boolean models to analyze the system dynamics, and the two have been found produce similar results in the cases analyzed. We ask whether or not Boolean models can generically reproduce the qualitative attractor dynamics of networks of continuously valued elements. Using a combination of analytical techniques and numerical simulations, we find that continuous networks exhibit two effects---an asymmetry between on and off states, and a decaying memory of events in each element's inputs---that are absent from synchronously updated Boolean models. We show that in simple loops these effects produce exactly the attractors that one would predict with an analysis of the stability of Boolean attractors, but in slightly more complicated topologies, they can destabilize solutions that are stable in the Boolean approximation, and can stabilize new attractors. Second, we investigate ensembles of large, random networks. Of particular interest is the transition between ordered and disordered dynamics, which is well characterized in Boolean systems. Networks at the

  19. Network analyses in systems pharmacology

    PubMed Central

    Berger, Seth I.; Iyengar, Ravi

    2009-01-01

    Systems pharmacology is an emerging area of pharmacology which utilizes network analysis of drug action as one of its approaches. By considering drug actions and side effects in the context of the regulatory networks within which the drug targets and disease gene products function, network analysis promises to greatly increase our knowledge of the mechanisms underlying the multiple actions of drugs. Systems pharmacology can provide new approaches for drug discovery for complex diseases. The integrated approach used in systems pharmacology can allow for drug action to be considered in the context of the whole genome. Network-based studies are becoming an increasingly important tool in understanding the relationships between drug action and disease susceptibility genes. This review discusses how analysis of biological networks has contributed to the genesis of systems pharmacology and how these studies have improved global understanding of drug targets, suggested new targets and approaches for therapeutics, and provided a deeper understanding of the effects of drugs. Taken together, these types of analyses can lead to new therapeutic options while improving the safety and efficacy of existing medications. Contact: ravi.iyengar@mssm.edu PMID:19648136

  20. Comparing genomes to computer operating systems in terms of the topology and evolution of their regulatory control networks.

    PubMed

    Yan, Koon-Kiu; Fang, Gang; Bhardwaj, Nitin; Alexander, Roger P; Gerstein, Mark

    2010-05-18

    The genome has often been called the operating system (OS) for a living organism. A computer OS is described by a regulatory control network termed the call graph, which is analogous to the transcriptional regulatory network in a cell. To apply our firsthand knowledge of the architecture of software systems to understand cellular design principles, we present a comparison between the transcriptional regulatory network of a well-studied bacterium (Escherichia coli) and the call graph of a canonical OS (Linux) in terms of topology and evolution. We show that both networks have a fundamentally hierarchical layout, but there is a key difference: The transcriptional regulatory network possesses a few global regulators at the top and many targets at the bottom; conversely, the call graph has many regulators controlling a small set of generic functions. This top-heavy organization leads to highly overlapping functional modules in the call graph, in contrast to the relatively independent modules in the regulatory network. We further develop a way to measure evolutionary rates comparably between the two networks and explain this difference in terms of network evolution. The process of biological evolution via random mutation and subsequent selection tightly constrains the evolution of regulatory network hubs. The call graph, however, exhibits rapid evolution of its highly connected generic components, made possible by designers' continual fine-tuning. These findings stem from the design principles of the two systems: robustness for biological systems and cost effectiveness (reuse) for software systems.

  1. Network operating system focus technology

    NASA Technical Reports Server (NTRS)

    1985-01-01

    An activity structured to provide specific design requirements and specifications for the Space Station Data Management System (DMS) Network Operating System (NOS) is outlined. Examples are given of the types of supporting studies and implementation tasks presently underway to realize a DMS test bed capability to develop hands-on understanding of NOS requirements as driven by actual subsystem test beds participating in the overall Johnson Space Center test bed program. Classical operating system elements and principal NOS functions are listed.

  2. Networked control of microgrid system of systems

    NASA Astrophysics Data System (ADS)

    Mahmoud, Magdi S.; Rahman, Mohamed Saif Ur; AL-Sunni, Fouad M.

    2016-08-01

    The microgrid has made its mark in distributed generation and has attracted widespread research. However, microgrid is a complex system which needs to be viewed from an intelligent system of systems perspective. In this paper, a network control system of systems is designed for the islanded microgrid system consisting of three distributed generation units as three subsystems supplying a load. The controller stabilises the microgrid system in the presence of communication infractions such as packet dropouts and delays. Simulation results are included to elucidate the effectiveness of the proposed control strategy.

  3. [Making a low cost IPSec router on Linux and the assessment for practical use].

    PubMed

    Amiki, M; Horio, M

    2001-09-01

    We installed Linux and FreeS/WAN on a PC/AT compatible machine to make an IPSec router. We measured the time of ping/ftp, only in the university, between the university and the external network. Between the university and the external network (the Internet), there were no differences. Therefore, we concluded that CPU load was not remarkable at low speed networks, because packets exchanged via the Internet are small, or compressions of VPN are more effective than encoding and decoding. On the other hand, in the university, the IPSec router performed down about 20-30% compared with normal IP communication, but this is not a serious problem for practical use. Recently, VPN machines are becoming cheaper, but they do not function sufficiently to create a fundamental VPN environment. Therefore, if one wants a fundamental VPN environment at a low cost, we believe you should select a VPN router on Linux.

  4. Architecting Communication Network of Networks for Space System of Systems

    NASA Technical Reports Server (NTRS)

    Bhasin, Kul B.; Hayden, Jeffrey L.

    2008-01-01

    The National Aeronautics and Space Administration (NASA) and the Department of Defense (DoD) are planning Space System of Systems (SoS) to address the new challenges of space exploration, defense, communications, navigation, Earth observation, and science. In addition, these complex systems must provide interoperability, enhanced reliability, common interfaces, dynamic operations, and autonomy in system management. Both NASA and the DoD have chosen to meet the new demands with high data rate communication systems and space Internet technologies that bring Internet Protocols (IP), routers, servers, software, and interfaces to space networks to enable as much autonomous operation of those networks as possible. These technologies reduce the cost of operations and, with higher bandwidths, support the expected voice, video, and data needed to coordinate activities at each stage of an exploration mission. In this paper, we discuss, in a generic fashion, how the architectural approaches and processes are being developed and used for defining a hypothetical communication and navigation networks infrastructure to support lunar exploration. Examples are given of the products generated by the architecture development process.

  5. Network command processing system overview

    NASA Technical Reports Server (NTRS)

    Nam, Yon-Woo; Murphy, Lisa D.

    1993-01-01

    The Network Command Processing System (NCPS) developed for the National Aeronautics and Space Administration (NASA) Ground Network (GN) stations is a spacecraft command system utilizing a MULTIBUS I/68030 microprocessor. This system was developed and implemented at ground stations worldwide to provide a Project Operations Control Center (POCC) with command capability for support of spacecraft operations such as the LANDSAT, Shuttle, Tracking and Data Relay Satellite, and Nimbus-7. The NCPS consolidates multiple modulation schemes for supporting various manned/unmanned orbital platforms. The NCPS interacts with the POCC and a local operator to process configuration requests, generate modulated uplink sequences, and inform users of the ground command link status. This paper presents the system functional description, hardware description, and the software design.

  6. The LILARTI neural network system

    SciTech Connect

    Allen, J.D. Jr.; Schell, F.M.; Dodd, C.V.

    1992-10-01

    The material of this Technical Memorandum is intended to provide the reader with conceptual and technical background information on the LILARTI neural network system of detail sufficient to confer an understanding of the LILARTI method as it is presently allied and to facilitate application of the method to problems beyond the scope of this document. Of particular importance in this regard are the descriptive sections and the Appendices which include operating instructions, partial listings of program output and data files, and network construction information.

  7. Autonomous telemetry system by using mobile networks for a long-term seismic observation

    NASA Astrophysics Data System (ADS)

    Hirahara, S.; Uchida, N.; Nakajima, J.

    2012-04-01

    When a large earthquake occurs, it is important to know the detailed distribution of aftershocks immediately after the main shock for the estimation of the fault plane. The large amount of seismic data is also required to determine the three-dimensional seismic velocity structure around the focal area. We have developed an autonomous telemetry system using mobile networks, which is specialized for aftershock observations. Because the newly developed system enables a quick installation and real-time data transmission by using mobile networks, we can construct a dense online seismic network even in mountain areas where conventional wired networks are not available. This system is equipped with solar panels that charge lead-acid battery, and enables a long-term seismic observation without maintenance. Furthermore, this system enables a continuous observation at low costs with flat-rate or prepaid Internet access. We have tried to expand coverage areas of mobile communication and back up Internet access by configuring plural mobile carriers. A micro server embedded with Linux consists of automatic control programs of the Internet connection and data transmission. A status monitoring and remote maintenance are available via the Internet. In case of a communication failure, an internal storage can back up data for two years. The power consumption of communication device ranges from 2.5 to 4.0 W. With a 50 Ah lead-acid battery, this system continues to record data for four days if the battery charging by solar panels is temporarily unavailable.

  8. PhyLIS: a simple GNU/Linux distribution for phylogenetics and phyloinformatics.

    PubMed

    Thomson, Robert C

    2009-07-30

    PhyLIS is a free GNU/Linux distribution that is designed to provide a simple, standardized platform for phylogenetic and phyloinformatic analysis. The operating system incorporates most commonly used phylogenetic software, which has been pre-compiled and pre-configured, allowing for straightforward application of phylogenetic methods and development of phyloinformatic pipelines in a stable Linux environment. The software is distributed as a live CD and can be installed directly or run from the CD without making changes to the computer. PhyLIS is available for free at http://www.eve.ucdavis.edu/rcthomson/phylis/.

  9. Real-time Periodic Processing of RT-middleware Utilizing Linux Standard Functionalities

    NASA Astrophysics Data System (ADS)

    Shimizu, Masaharu; Toda, Kengo; Hayashibara, Yasuo; Yamato, Hideaki; Furuta, Takayuki

    A new methodology of real-time periodic processing on RT-middleware based on the Linux standard functionalities is presented in this paper. The central of discussion is on the realization of real-time processing while keeping the reusability of software modules ensured by the RT-middleware framework as well as the portability provided by the Linux development mainstream. In order to show the validity of the proposed approach, two robot systems, including an omnidirectional electric wheelchair steered by haptic joystick, are presented and the discussion about the evaluation result follows from the view point of practicality.

  10. Tri-Laboratory Linux Capacity Cluster 2007 SOW

    SciTech Connect

    Seager, M

    2007-03-22

    well, the budget demands are extreme and new, more cost effective ways of fielding these systems must be developed. This Tri-Laboratory Linux Capacity Cluster (TLCC) procurement represents the ASC first investment vehicle in these capacity systems. It also represents a new strategy for quickly building, fielding and integrating many Linux clusters of various sizes into classified and unclassified production service through a concept of Scalable Units (SU). The programmatic objective is to dramatically reduce the overall Total Cost of Ownership (TCO) of these 'capacity' systems relative to the best practices in Linux Cluster deployments today. This objective only makes sense in the context of these systems quickly becoming very robust and useful production clusters under the crushing load that will be inflicted on them by the ASC and SSP scientific simulation capacity workload.

  11. The AMSC network control system

    NASA Technical Reports Server (NTRS)

    Garner, William B.

    1990-01-01

    The American Mobile Satellite Corporation (AMSC) is going to construct, launch, and operate a satellite system in order to provide mobile satellite services to the United States. AMSC is going to build, own, and operate a Network Control System (NCS) for managing the communications usage of the satellites, and to control circuit switched access between mobile earth terminals and feeder-link earth stations. An overview of the major NCS functional and performance requirements, the control system physical architecture, and the logical architecture is provided.

  12. Network Centrality of Metro Systems

    PubMed Central

    Derrible, Sybil

    2012-01-01

    Whilst being hailed as the remedy to the world’s ills, cities will need to adapt in the 21st century. In particular, the role of public transport is likely to increase significantly, and new methods and technics to better plan transit systems are in dire need. This paper examines one fundamental aspect of transit: network centrality. By applying the notion of betweenness centrality to 28 worldwide metro systems, the main goal of this paper is to study the emergence of global trends in the evolution of centrality with network size and examine several individual systems in more detail. Betweenness was notably found to consistently become more evenly distributed with size (i.e. no “winner takes all”) unlike other complex network properties. Two distinct regimes were also observed that are representative of their structure. Moreover, the share of betweenness was found to decrease in a power law with size (with exponent 1 for the average node), but the share of most central nodes decreases much slower than least central nodes (0.87 vs. 2.48). Finally the betweenness of individual stations in several systems were examined, which can be useful to locate stations where passengers can be redistributed to relieve pressure from overcrowded stations. Overall, this study offers significant insights that can help planners in their task to design the systems of tomorrow, and similar undertakings can easily be imagined to other urban infrastructure systems (e.g., electricity grid, water/wastewater system, etc.) to develop more sustainable cities. PMID:22792373

  13. Linux OS Jitter Measurements at Large Node Counts using a BlueGene/L

    SciTech Connect

    Jones, Terry R; Tauferner, Mr. Andrew; Inglett, Mr. Todd

    2010-01-01

    We present experimental results for a coordinated scheduling implementation of the Linux operating system. Results were collected on an IBM Blue Gene/L machine at scales up to 16K nodes. Our results indicate coordinated scheduling was able to provide a dramatic improvement in scaling performance for two applications characterized as bulk synchronous parallel programs.

  14. Modeling Computer Communication Networks in a Realistic 3D Environment

    DTIC Science & Technology

    2010-03-01

    system throughput, packet loss, and network congestion as a function of time. This not only gives a better understanding of the network, but it also...only runs on Microsoft Windows, which precludes portability to UNIX-based systems such as Linux or Apple OSX. 3ds Max allows for very extensive scene...simulation. It is often desirable to display this data visually, in order to capitalize on the unique capabilities of the human visual system which

  15. Malware Memory Analysis of the Jynx2 Linux Rootkit (Part 1): Investigating a Publicly Available Linux Rootkit Using the Volatility Memory Analysis Framework

    DTIC Science & Technology

    2014-10-01

    analysis of virulent software always carry some inherent risk that must be securely managed and adequately mitigated. An in-depth study of memory...analysis techniques is outside the scope of this work, as it requires a comprehensive study of operating system internals and software reverse engineering...a working knowledge of Linux, basic system administration and software compilation. Unlike the previous Windows-based reports, it was determined

  16. Impact on TRMM Products of Conversion to Linux

    NASA Technical Reports Server (NTRS)

    Stocker, Erich Franz; Kwiatkowski, John

    2008-01-01

    In June 2008, TRMM data processing will be assumed by the Precipitation Processing System (PPS). This change will also mean a change in the hardware production environment from an SGI 32 bit IRIX processing environment to a Linux (Beowulf) 64 bit processing environment. This change of platform and operating system addressing (32 to 64) has some influence on data values in the TRMM data products. This paper will describe the transition architecture and scheduling. It will also provide an analysis of what the nature of the product differences will be. It will demonstrate that the differences are not scientifically significant and are generally not visible. However, they are not always identical with those which the SGI would produce.

  17. Improving Memory Error Handling Using Linux

    SciTech Connect

    Carlton, Michael Andrew; Blanchard, Sean P.; Debardeleben, Nathan A.

    2014-07-25

    As supercomputers continue to get faster and more powerful in the future, they will also have more nodes. If nothing is done, then the amount of memory in supercomputer clusters will soon grow large enough that memory failures will be unmanageable to deal with by manually replacing memory DIMMs. "Improving Memory Error Handling Using Linux" is a process oriented method to solve this problem by using the Linux kernel to disable (offline) faulty memory pages containing bad addresses, preventing them from being used again by a process. The process of offlining memory pages simplifies error handling and results in reducing both hardware and manpower costs required to run Los Alamos National Laboratory (LANL) clusters. This process will be necessary for the future of supercomputing to allow the development of exascale computers. It will not be feasible without memory error handling to manually replace the number of DIMMs that will fail daily on a machine consisting of 32-128 petabytes of memory. Testing reveals the process of offlining memory pages works and is relatively simple to use. As more and more testing is conducted, the entire process will be automated within the high-performance computing (HPC) monitoring software, Zenoss, at LANL.

  18. High Performance Diskless Linux Workstations in AX-Division

    SciTech Connect

    Councell, E; Busby, L

    2003-09-30

    AX Division has recently installed a number of diskless Linux workstations to meet the needs of its scientific staff for classified processing. Results so far are quite positive, although problems do remain. Some unusual requirements were met using a novel, but simple, design: Each diskless client has a dedicated partition on a server disk that contains a complete Linux distribution.

  19. Radar System Classification Using Neural Networks

    DTIC Science & Technology

    1991-12-01

    This study investigated methods of improving the accuracy of neural networks in the classification of large numbers of classes. A literature search...revealed that neural networks have been successful in the radar classification problem, and that many complex problems have been solved using systems...of multiple neural networks . The experiments conducted were based on 32 classes of radar system data. The neural networks were modelled using a program

  20. Performance Evaluation of Multi-Channel Wireless Mesh Networks with Embedded Systems

    PubMed Central

    Lam, Jun Huy; Lee, Sang-Gon; Tan, Whye Kit

    2012-01-01

    Many commercial wireless mesh network (WMN) products are available in the marketplace with their own proprietary standards, but interoperability among the different vendors is not possible. Open source communities have their own WMN implementation in accordance with the IEEE 802.11s draft standard, Linux open80211s project and FreeBSD WMN implementation. While some studies have focused on the test bed of WMNs based on the open80211s project, none are based on the FreeBSD. In this paper, we built an embedded system using the FreeBSD WMN implementation that utilizes two channels and evaluated its performance. This implementation allows the legacy system to connect to the WMN independent of the type of platform and distributes the load between the two non-overlapping channels. One channel is used for the backhaul connection and the other one is used to connect to the stations to wireless mesh network. By using the power efficient 802.11 technology, this device can also be used as a gateway for the wireless sensor network (WSN). PMID:22368482

  1. Performance evaluation of multi-channel wireless mesh networks with embedded systems.

    PubMed

    Lam, Jun Huy; Lee, Sang-Gon; Tan, Whye Kit

    2012-01-01

    Many commercial wireless mesh network (WMN) products are available in the marketplace with their own proprietary standards, but interoperability among the different vendors is not possible. Open source communities have their own WMN implementation in accordance with the IEEE 802.11s draft standard, Linux open80211s project and FreeBSD WMN implementation. While some studies have focused on the test bed of WMNs based on the open80211s project, none are based on the FreeBSD. In this paper, we built an embedded system using the FreeBSD WMN implementation that utilizes two channels and evaluated its performance. This implementation allows the legacy system to connect to the WMN independent of the type of platform and distributes the load between the two non-overlapping channels. One channel is used for the backhaul connection and the other one is used to connect to the stations to wireless mesh network. By using the power efficient 802.11 technology, this device can also be used as a gateway for the wireless sensor network (WSN).

  2. A system dynamics model for communications networks

    NASA Astrophysics Data System (ADS)

    Awcock, A. J.; King, T. E. G.

    1985-09-01

    An abstract model of a communications network in system dynamics terminology is developed as implementation of this model by a FORTRAN program package developed at RSRE is discussed. The result of this work is a high-level simulation package in which the performance of adaptive routing algorithms and other network controls may be assessed for a network of arbitrary topology.

  3. Kennedy Space Center network documentation system

    NASA Technical Reports Server (NTRS)

    Lohne, William E.; Schuerger, Charles L.

    1995-01-01

    The Kennedy Space Center Network Documentation System (KSC NDS) is being designed and implemented by NASA and the KSC contractor organizations to provide a means of network tracking, configuration, and control. Currently, a variety of host and client platforms are in use as a result of each organization having established its own network documentation system. The solution is to incorporate as many existing 'systems' as possible in the effort to consolidate and standardize KSC-wide documentation.

  4. Operating systems and network protocols for wireless sensor networks.

    PubMed

    Dutta, Prabal; Dunkels, Adam

    2012-01-13

    Sensor network protocols exist to satisfy the communication needs of diverse applications, including data collection, event detection, target tracking and control. Network protocols to enable these services are constrained by the extreme resource scarcity of sensor nodes-including energy, computing, communications and storage-which must be carefully managed and multiplexed by the operating system. These challenges have led to new protocols and operating systems that are efficient in their energy consumption, careful in their computational needs and miserly in their memory footprints, all while discovering neighbours, forming networks, delivering data and correcting failures.

  5. Statistically Validated Networks in Bipartite Complex Systems

    PubMed Central

    Tumminello, Michele; Miccichè, Salvatore; Lillo, Fabrizio; Piilo, Jyrki; Mantegna, Rosario N.

    2011-01-01

    Many complex systems present an intrinsic bipartite structure where elements of one set link to elements of the second set. In these complex systems, such as the system of actors and movies, elements of one set are qualitatively different than elements of the other set. The properties of these complex systems are typically investigated by constructing and analyzing a projected network on one of the two sets (for example the actor network or the movie network). Complex systems are often very heterogeneous in the number of relationships that the elements of one set establish with the elements of the other set, and this heterogeneity makes it very difficult to discriminate links of the projected network that are just reflecting system's heterogeneity from links relevant to unveil the properties of the system. Here we introduce an unsupervised method to statistically validate each link of a projected network against a null hypothesis that takes into account system heterogeneity. We apply the method to a biological, an economic and a social complex system. The method we propose is able to detect network structures which are very informative about the organization and specialization of the investigated systems, and identifies those relationships between elements of the projected network that cannot be explained simply by system heterogeneity. We also show that our method applies to bipartite systems in which different relationships might have different qualitative nature, generating statistically validated networks in which such difference is preserved. PMID:21483858

  6. Method and system for mesh network embedded devices

    NASA Technical Reports Server (NTRS)

    Wang, Ray (Inventor)

    2009-01-01

    A method and system for managing mesh network devices. A mesh network device with integrated features creates an N-way mesh network with a full mesh network topology or a partial mesh network topology.

  7. Broadband network on-line data acquisition system with web based interface for control and basic analysis

    NASA Astrophysics Data System (ADS)

    Polkowski, Marcin; Grad, Marek

    2016-04-01

    Passive seismic experiment "13BB Star" is operated since mid 2013 in northern Poland and consists of 13 broadband seismic stations. One of the elements of this experiment is dedicated on-line data acquisition system comprised of both client (station) side and server side modules with web based interface that allows monitoring of network status and provides tools for preliminary data analysis. Station side is controlled by ARM Linux board that is programmed to maintain 3G/EDGE internet connection, receive data from digitizer, send data do central server among with additional auxiliary parameters like temperatures, voltages and electric current measurements. Station side is controlled by set of easy to install PHP scripts. Data is transmitted securely over SSH protocol to central server. Central server is a dedicated Linux based machine. Its duty is receiving and processing all data from all stations including auxiliary parameters. Server side software is written in PHP and Python. Additionally, it allows remote station configuration and provides web based interface for user friendly interaction. All collected data can be displayed for each day and station. It also allows manual creation of event oriented plots with different filtering abilities and provides numerous status and statistic information. Our solution is very flexible and easy to modify. In this presentation we would like to share our solution and experience. National Science Centre Poland provided financial support for this work via NCN grant DEC-2011/02/A/ST10/00284.

  8. A Neural Network Object Recognition System

    DTIC Science & Technology

    1990-07-01

    useful for exploring different neural network configurations. There are three main computation phases of a model based object recognition system...segmentation, feature extraction, and object classification. This report focuses on the object classification stage. For segmentation, a neural network based...are available with the current system. Neural network based feature extraction may be added at a later date. The classification stage consists of a

  9. NASDA knowledge-based network planning system

    NASA Technical Reports Server (NTRS)

    Yamaya, K.; Fujiwara, M.; Kosugi, S.; Yambe, M.; Ohmori, M.

    1993-01-01

    One of the SODS (space operation and data system) sub-systems, NP (network planning) was the first expert system used by NASDA (national space development agency of Japan) for tracking and control of satellite. The major responsibilities of the NP system are: first, the allocation of network and satellite control resources and, second, the generation of the network operation plan data (NOP) used in automated control of the stations and control center facilities. Up to now, the first task of network resource scheduling was done by network operators. NP system automatically generates schedules using its knowledge base, which contains information on satellite orbits, station availability, which computer is dedicated to which satellite, and how many stations must be available for a particular satellite pass or a certain time period. The NP system is introduced.

  10. Empirical tests of Zipf's law mechanism in open source Linux distribution.

    PubMed

    Maillart, T; Sornette, D; Spaeth, S; von Krogh, G

    2008-11-21

    Zipf's power law is a ubiquitous empirical regularity found in many systems, thought to result from proportional growth. Here, we establish empirically the usually assumed ingredients of stochastic growth models that have been previously conjectured to be at the origin of Zipf's law. We use exceptionally detailed data on the evolution of open source software projects in Linux distributions, which offer a remarkable example of a growing complex self-organizing adaptive system, exhibiting Zipf's law over four full decades.

  11. Multidisciplinary Studies of Integrated Neural Network Systems

    DTIC Science & Technology

    1994-03-01

    They accomplish this by partitioning the system into functional sub-units in a quasi-hierarchical structure of neural network modules. We studied...three specific examples of this system integration strategy and modeled their operation for the purpose of creating new neural network architectures and

  12. Enterprise networks. Strategies for integrated delivery systems.

    PubMed

    Siwicki, B

    1997-02-01

    More integrated delivery systems are making progress toward building computer networks that link all their care delivery sites so they can efficiently and economically coordinate care. A growing number of these systems are turning to intranets--private computer networks that use Internet-derived protocols and technologies--to move information that's essential to managing scare health care resources.

  13. Systemic risk on different interbank network topologies

    NASA Astrophysics Data System (ADS)

    Lenzu, Simone; Tedeschi, Gabriele

    2012-09-01

    In this paper we develop an interbank market with heterogeneous financial institutions that enter into lending agreements on different network structures. Credit relationships (links) evolve endogenously via a fitness mechanism based on agents' performance. By changing the agent's trust on its neighbor's performance, interbank linkages self-organize themselves into very different network architectures, ranging from random to scale-free topologies. We study which network architecture can make the financial system more resilient to random attacks and how systemic risk spreads over the network. To perturb the system, we generate a random attack via a liquidity shock. The hit bank is not automatically eliminated, but its failure is endogenously driven by its incapacity to raise liquidity in the interbank network. Our analysis shows that a random financial network can be more resilient than a scale free one in case of agents' heterogeneity.

  14. Neural network based system for equipment surveillance

    DOEpatents

    Vilim, R.B.; Gross, K.C.; Wegerich, S.W.

    1998-04-28

    A method and system are disclosed for performing surveillance of transient signals of an industrial device to ascertain the operating state. The method and system involves the steps of reading into a memory training data, determining neural network weighting values until achieving target outputs close to the neural network output. If the target outputs are inadequate, wavelet parameters are determined to yield neural network outputs close to the desired set of target outputs and then providing signals characteristic of an industrial process and comparing the neural network output to the industrial process signals to evaluate the operating state of the industrial process. 33 figs.

  15. Neural network based system for equipment surveillance

    DOEpatents

    Vilim, Richard B.; Gross, Kenneth C.; Wegerich, Stephan W.

    1998-01-01

    A method and system for performing surveillance of transient signals of an industrial device to ascertain the operating state. The method and system involves the steps of reading into a memory training data, determining neural network weighting values until achieving target outputs close to the neural network output. If the target outputs are inadequate, wavelet parameters are determined to yield neural network outputs close to the desired set of target outputs and then providing signals characteristic of an industrial process and comparing the neural network output to the industrial process signals to evaluate the operating state of the industrial process.

  16. Network Physiology: How Organ Systems Dynamically Interact.

    PubMed

    Bartsch, Ronny P; Liu, Kang K L; Bashan, Amir; Ivanov, Plamen Ch

    2015-01-01

    We systematically study how diverse physiologic systems in the human organism dynamically interact and collectively behave to produce distinct physiologic states and functions. This is a fundamental question in the new interdisciplinary field of Network Physiology, and has not been previously explored. Introducing the novel concept of Time Delay Stability (TDS), we develop a computational approach to identify and quantify networks of physiologic interactions from long-term continuous, multi-channel physiological recordings. We also develop a physiologically-motivated visualization framework to map networks of dynamical organ interactions to graphical objects encoded with information about the coupling strength of network links quantified using the TDS measure. Applying a system-wide integrative approach, we identify distinct patterns in the network structure of organ interactions, as well as the frequency bands through which these interactions are mediated. We establish first maps representing physiologic organ network interactions and discover basic rules underlying the complex hierarchical reorganization in physiologic networks with transitions across physiologic states. Our findings demonstrate a direct association between network topology and physiologic function, and provide new insights into understanding how health and distinct physiologic states emerge from networked interactions among nonlinear multi-component complex systems. The presented here investigations are initial steps in building a first atlas of dynamic interactions among organ systems.

  17. Cooperative Networks of Learning Systems.

    ERIC Educational Resources Information Center

    Lewis, Arthur J.; Blalock, Carol D.

    1981-01-01

    Proposes locally-generated service-learning networks which will allow disadvantaged communities both to capitalize on existing resources and to develop new vehicles for education. Condensed from "Synergist," Winter 1981, pp38-41. (Author/SJL)

  18. High-speed, intra-system networks

    SciTech Connect

    Quinn, Heather M; Graham, Paul S; Manuzzato, Andrea; Fairbanks, Tom; Dallmann, Nicholas; Desgeorges, Rose

    2010-06-28

    Recently, engineers have been studying on-payload networks for fast communication paths. Using intra-system networks as a means to connect devices together allows for a flexible payload design that does not rely on dedicated communication paths between devices. In this manner, the data flow architecture of the system can be dynamically reconfigured to allow data routes to be optimized for the application or configured to route around devices that are temporarily or permanently unavailable. To use intra-system networks, devices will need network controllers and switches. These devices are likely to be affected by single-event effects, which could affect data communication. In this paper we will present radiation data and performance analysis for using a Broadcom network controller in a neutron environment.

  19. ANPS - AUTOMATIC NETWORK PROGRAMMING SYSTEM

    NASA Technical Reports Server (NTRS)

    Schroer, B. J.

    1994-01-01

    Development of some of the space program's large simulation projects -- like the project which involves simulating the countdown sequence prior to spacecraft liftoff -- requires the support of automated tools and techniques. The number of preconditions which must be met for a successful spacecraft launch and the complexity of their interrelationship account for the difficulty of creating an accurate model of the countdown sequence. Researchers developed ANPS for the Nasa Marshall Space Flight Center to assist programmers attempting to model the pre-launch countdown sequence. Incorporating the elements of automatic programming as its foundation, ANPS aids the user in defining the problem and then automatically writes the appropriate simulation program in GPSS/PC code. The program's interactive user dialogue interface creates an internal problem specification file from user responses which includes the time line for the countdown sequence, the attributes for the individual activities which are part of a launch, and the dependent relationships between the activities. The program's automatic simulation code generator receives the file as input and selects appropriate macros from the library of software modules to generate the simulation code in the target language GPSS/PC. The user can recall the problem specification file for modification to effect any desired changes in the source code. ANPS is designed to write simulations for problems concerning the pre-launch activities of space vehicles and the operation of ground support equipment and has potential for use in developing network reliability models for hardware systems and subsystems. ANPS was developed in 1988 for use on IBM PC or compatible machines. The program requires at least 640 KB memory and one 360 KB disk drive, PC DOS Version 2.0 or above, and GPSS/PC System Version 2.0 from Minuteman Software. The program is written in Turbo Prolog Version 2.0. GPSS/PC is a trademark of Minuteman Software. Turbo Prolog

  20. Networking: What Are the Alternative Systems.

    ERIC Educational Resources Information Center

    Connell, Cassie C.

    1981-01-01

    Educational institutions use networks to connect devices to a common line or central course to share resources. Presented is information for selecting the best network system for present and future needs. Discusses configuration of line; transmission methods, rates, and lines; cable length; price; and interfacing. (DC)

  1. The Networking of Interactive Bibliographic Retrieval Systems.

    ERIC Educational Resources Information Center

    Marcus, Richard S.; Reintjes, J. Francis

    Research in networking of heterogeneous interactive bibliographic retrieval systems is being conducted which centers on the concept of a virtual retrieval system. Such a virtual system would be created through a translating computer interface that would provide access to the different retrieval systems and data bases in a uniform and convenient…

  2. Fast predictive control of networked energy systems

    NASA Astrophysics Data System (ADS)

    Chuang, Frank Fu-Han

    In this thesis we study the optimal control of networked energy systems. Networked energy systems consist of a collection of energy storage nodes and a network of links and inputs which allow energy to be exchanged, injected, or removed from the nodes. The nodes may exchange energy between each other autonomously or via controlled flows between the nodes. Examples of networked systems include building heating, ventilation, and air conditioning (HVAC) systems and networked battery systems. In the building system example, the nodes of the system are rooms which store thermal energy in the air and other elements which have thermal capacity. The rooms transfer energy autonomously through thermal conduction, convection, and radiation. Thermal energy can be injected into or removed from the rooms via conditioned air or slabs. In the case of a networked battery system, the batteries store electrical energy in their chemical cells. The batteries may be electrically linked so that a controller can move electrical charge from one battery to another. Networked energy systems are typically large-scale (contain many states and inputs), affected by uncertain forecasts and disturbances, and require fast computation on cheap embedded platforms. In this thesis, the optimal control technique we study is model predictive control for networked energy systems. Model predictive or receding horizon control is a time-domain optimization-based control technique which uses predictive models of a system to forecast its behavior and minimize a performance cost subject to system constraints. In this thesis we address two primary issues concerning model predictive control for networked energy systems: robustness to uncertainty in forecasts and reducing the complexity of the large-scale optimization problem for use in embedded platforms. The first half of the thesis deals primarily with the efficient computation of robust controllers for dealing with random and adversarial uncertainties in the

  3. Gradient systems on coupled cell networks

    NASA Astrophysics Data System (ADS)

    Manoel, Miriam; Roberts, Mark

    2015-10-01

    For networks of coupled dynamical systems we characterize admissible functions, that is, functions whose gradient is an admissible vector field. The schematic representation of a gradient network dynamical system is of an undirected cell graph, and we use tools from graph theory to deduce the general form of such functions, relating it to the topological structure of the graph defining the network. The coupling of pairs of dynamical systems cells is represented by edges of the graph, and from spectral graph theory we detect the existence and nature of equilibria of the gradient system from the critical points of the coupling function. In particular, we study fully synchronous and 2-state patterns of equilibria on regular graphs. These are two special types of equilibrium configurations for gradient networks. We also investigate equilibrium configurations of {{\\mathbf{S}}1} -invariant admissible functions on a ring of cells.

  4. Network support for system initiated checkpoints

    DOEpatents

    Chen, Dong; Heidelberger, Philip

    2013-01-29

    A system, method and computer program product for supporting system initiated checkpoints in parallel computing systems. The system and method generates selective control signals to perform checkpointing of system related data in presence of messaging activity associated with a user application running at the node. The checkpointing is initiated by the system such that checkpoint data of a plurality of network nodes may be obtained even in the presence of user applications running on highly parallel computers that include ongoing user messaging activity.

  5. Progress in photonic transport network systems

    NASA Astrophysics Data System (ADS)

    Sato, Ken-Ichi

    2002-07-01

    The network paradigm is changing rapidly spurred by the dramatic increase in IP traffic and recent progress in photonic network technologies. A key requirement, enhancing the performance of existing IP-based multimedia communication networks, can be most effectively achieved by introducing optical path technologies that exploit wavelength routing. Cost effective and reliable optical cross-connection is essential. Different optical switch technologies have been proposed and tested. Among them, the PLC (Planer Lightwave Circuit) switch has demonstrated excellent performance, particularly with regard to system reliability. Network control mechanisms based on the overlay and peer model models have been developed. The presentation will highlight some of the key system technologies. To develop very large scale and robust networks, effective traffic engineering capabilities are necessary. This will be achieved through optical path control. To develop future IP-centric networks, an operation mechanism based on distributed control is important. The degree to which the necessary transport and IP routing functions are integrated will determine system cost-effectiveness. The Photonic MPLS (Multi Protocol Label Switching) router, which integrates all the functions and provides seamless operation between IP and optical layers, has been proposed and developed. The technical feasibility of a recent prototype system has been proven. Finally, some of the cutting-edge photonic transport technologies that we have recently developed are demonstrated; these technologies will enable us to achieve another level of network performance enhancement in the future.

  6. Network representations of immune system complexity

    PubMed Central

    Subramanian, Naeha; Torabi-Parizi, Parizad; Gottschalk, Rachel A.; Germain, Ronald N.; Dutta, Bhaskar

    2015-01-01

    The mammalian immune system is a dynamic multi-scale system composed of a hierarchically organized set of molecular, cellular and organismal networks that act in concert to promote effective host defense. These networks range from those involving gene regulatory and protein-protein interactions underlying intracellular signaling pathways and single cell responses to increasingly complex networks of in vivo cellular interaction, positioning and migration that determine the overall immune response of an organism. Immunity is thus not the product of simple signaling events but rather non-linear behaviors arising from dynamic, feedback-regulated interactions among many components. One of the major goals of systems immunology is to quantitatively measure these complex multi-scale spatial and temporal interactions, permitting development of computational models that can be used to predict responses to perturbation. Recent technological advances permit collection of comprehensive datasets at multiple molecular and cellular levels while advances in network biology support representation of the relationships of components at each level as physical or functional interaction networks. The latter facilitate effective visualization of patterns and recognition of emergent properties arising from the many interactions of genes, molecules, and cells of the immune system. We illustrate the power of integrating ‘omics’ and network modeling approaches for unbiased reconstruction of signaling and transcriptional networks with a focus on applications involving the innate immune system. We further discuss future possibilities for reconstruction of increasingly complex cellular and organism-level networks and development of sophisticated computational tools for prediction of emergent immune behavior arising from the concerted action of these networks. PMID:25625853

  7. The labeled systems of multiple neural networks.

    PubMed

    Nemissi, M; Seridi, H; Akdag, H

    2008-08-01

    This paper proposes an implementation scheme of K-class classification problem using systems of multiple neural networks. Usually, a multi-class problem is decomposed into simple sub-problems solved independently using similar single neural networks. For the reason that these sub-problems are not equivalent in their complexity, we propose a system that includes reinforced networks destined to solve complicated parts of the entire problem. Our approach is inspired from principles of the multi-classifiers systems and the labeled classification, which aims to improve performances of the networks trained by the Back-Propagation algorithm. We propose two implementation schemes based on both OAO (one-against-all) and OAA (one-against-one). The proposed models are evaluated using iris and human thigh databases.

  8. A neural network based speech recognition system

    NASA Astrophysics Data System (ADS)

    Carroll, Edward J.; Coleman, Norman P., Jr.; Reddy, G. N.

    1990-02-01

    An overview is presented of the development of a neural network based speech recognition system. The two primary tasks involved were the development of a time invariant speech encoder and a pattern recognizer or detector. The speech encoder uses amplitude normalization and a Fast Fourier Transform to eliminate amplitude and frequency shifts of acoustic clues. The detector consists of a back-propagation network which accepts data from the encoder and identifies individual words. This use of neural networks offers two advantages over conventional algorithmic detectors: the detection time is no more than a few network time constants, and its recognition speed is independent of the number of the words in the vocabulary. The completed system has functioned as expected with high tolerance to input variation and with error rates comparable to a commercial system when used in a noisy environment.

  9. Dissecting a Network-Based Education System

    ERIC Educational Resources Information Center

    Davis, Tiffany; Yoo, Seong-Moo; Pan, Wendi

    2005-01-01

    The Alabama Learning Exchange (ALEX; www.alex.state.al.us) is a network-based education system designed and implemented to help improve education in Alabama. It accomplishes this goal by providing a single location for the state's K-12 educators to find information that will help improve their classroom effectiveness. The ALEX system includes…

  10. Network analysis of eight industrial symbiosis systems

    NASA Astrophysics Data System (ADS)

    Zhang, Yan; Zheng, Hongmei; Shi, Han; Yu, Xiangyi; Liu, Gengyuan; Su, Meirong; Li, Yating; Chai, Yingying

    2016-06-01

    Industrial symbiosis is the quintessential characteristic of an eco-industrial park. To divide parks into different types, previous studies mostly focused on qualitative judgments, and failed to use metrics to conduct quantitative research on the internal structural or functional characteristics of a park. To analyze a park's structural attributes, a range of metrics from network analysis have been applied, but few researchers have compared two or more symbioses using multiple metrics. In this study, we used two metrics (density and network degree centralization) to compare the degrees of completeness and dependence of eight diverse but representative industrial symbiosis networks. Through the combination of the two metrics, we divided the networks into three types: weak completeness, and two forms of strong completeness, namely "anchor tenant" mutualism and "equality-oriented" mutualism. The results showed that the networks with a weak degree of completeness were sparse and had few connections among nodes; for "anchor tenant" mutualism, the degree of completeness was relatively high, but the affiliated members were too dependent on core members; and the members in "equality-oriented" mutualism had equal roles, with diverse and flexible symbiotic paths. These results revealed some of the systems' internal structure and how different structures influenced the exchanges of materials, energy, and knowledge among members of a system, thereby providing insights into threats that may destabilize the network. Based on this analysis, we provide examples of the advantages and effectiveness of recent improvement projects in a typical Chinese eco-industrial park (Shandong Lubei).

  11. A dynamical systems view of network centrality

    PubMed Central

    Grindrod, Peter; Higham, Desmond J.

    2014-01-01

    To gain insights about dynamic networks, the dominant paradigm is to study discrete snapshots, or timeslices, as the interactions evolve. Here, we develop and test a new mathematical framework where network evolution is handled over continuous time, giving an elegant dynamical systems representation for the important concept of node centrality. The resulting system allows us to track the relative influence of each individual. This new setting is natural in many digital applications, offering both conceptual and computational advantages. The novel differential equations approach is convenient for modelling and analysis of network evolution and gives rise to an interesting application of the matrix logarithm function. From a computational perspective, it avoids the awkward up-front compromises between accuracy, efficiency and redundancy required in the prevalent discrete-time setting. Instead, we can rely on state-of-the-art ODE software, where discretization takes place adaptively in response to the prevailing system dynamics. The new centrality system generalizes the widely used Katz measure, and allows us to identify and track, at any resolution, the most influential nodes in terms of broadcasting and receiving information through time-dependent links. In addition to the classical static network notion of attenuation across edges, the new ODE also allows for attenuation over time, as information becomes stale. This allows ‘running measures’ to be computed, so that networks can be monitored in real time over arbitrarily long intervals. With regard to computational efficiency, we explain why it is cheaper to track good receivers of information than good broadcasters. An important consequence is that the overall broadcast activity in the network can also be monitored efficiently. We use two synthetic examples to validate the relevance of the new measures. We then illustrate the ideas on a large-scale voice call network, where key features are discovered that are

  12. Social network supported process recommender system.

    PubMed

    Ye, Yanming; Yin, Jianwei; Xu, Yueshen

    2014-01-01

    Process recommendation technologies have gained more and more attention in the field of intelligent business process modeling to assist the process modeling. However, most of the existing technologies only use the process structure analysis and do not take the social features of processes into account, while the process modeling is complex and comprehensive in most situations. This paper studies the feasibility of social network research technologies on process recommendation and builds a social network system of processes based on the features similarities. Then, three process matching degree measurements are presented and the system implementation is discussed subsequently. Finally, experimental evaluations and future works are introduced.

  13. Network Speech Systems Technology Program.

    DTIC Science & Technology

    1979-09-30

    utilized for the digital speech. As discussed in Ref . 8, the required control overhead for packet transmission can be reduced to a level comparable...multiplexer with fixed-channel capacity are discussed in Ref . 17. For the multi-node system considered here, the effects of both fixed- and variable...Phase IV and described in Ref . 2. We then ran a comparison among centrally controlled simplex broadcast and speaker/interrupter systems together with the

  14. Multifractal nature of network induced time delay in networked control systems

    NASA Astrophysics Data System (ADS)

    Tian, Yu-Chu; Yu, Zu-Guo; Fidge, Colin

    2007-01-01

    When modelling and simulating networked control systems (NCSs) over TCP/IP network protocols, we obtained network traffic data sets with irregular behaviour. Analysing the data sets revealed multifractal network traffic. Typical data sets are given in this Letter together with our preliminary analysis. The network architecture and traffic specifications that generated the multifractal traffic are also described in detail.

  15. MOLAR: Modular Linux and Adaptive Runtime Support for HEC OS/R Research

    SciTech Connect

    Frank Mueller

    2009-02-05

    MOLAR is a multi-institution research effort that concentrates on adaptive, reliable,and efficient operating and runtime system solutions for ultra-scale high-end scientific computing on the next generation of supercomputers. This research addresses the challenges outlined by the FAST-OS - forum to address scalable technology for runtime and operating systems --- and HECRTF --- high-end computing revitalization task force --- activities by providing a modular Linux and adaptable runtime support for high-end computing operating and runtime systems. The MOLAR research has the following goals to address these issues. (1) Create a modular and configurable Linux system that allows customized changes based on the requirements of the applications, runtime systems, and cluster management software. (2) Build runtime systems that leverage the OS modularity and configurability to improve efficiency, reliability, scalability, ease-of-use, and provide support to legacy and promising programming models. (3) Advance computer reliability, availability and serviceability (RAS) management systems to work cooperatively with the OS/R to identify and preemptively resolve system issues. (4) Explore the use of advanced monitoring and adaptation to improve application performance and predictability of system interruptions. The overall goal of the research conducted at NCSU is to develop scalable algorithms for high-availability without single points of failure and without single points of control.

  16. Linux Adventures on a Laptop. Computers in Small Libraries

    ERIC Educational Resources Information Center

    Roberts, Gary

    2005-01-01

    This article discusses the pros and cons of open source software, such as Linux. It asserts that despite the technical difficulties of installing and maintaining this type of software, ultimately it is helpful in terms of knowledge acquisition and as a beneficial investment librarians can make in themselves, their libraries, and their patrons.…

  17. Drowning in PC Management: Could a Linux Solution Save Us?

    ERIC Educational Resources Information Center

    Peters, Kathleen A.

    2004-01-01

    Short on funding and IT staff, a Western Canada library struggled to provide adequate public computing resources. Staff turned to a Linux-based solution that supports up to 10 users from a single computer, and blends Web browsing and productivity applications with session management, Internet filtering, and user authentication. In this article,…

  18. Teaching Hands-On Linux Host Computer Security

    ERIC Educational Resources Information Center

    Shumba, Rose

    2006-01-01

    In the summer of 2003, a project to augment and improve the teaching of information assurance courses was started at IUP. Thus far, ten hands-on exercises have been developed. The exercises described in this article, and presented in the appendix, are based on actions required to secure a Linux host. Publicly available resources were used to…

  19. Social networks as embedded complex adaptive systems.

    PubMed

    Benham-Hutchins, Marge; Clancy, Thomas R

    2010-09-01

    As systems evolve over time, their natural tendency is to become increasingly more complex. Studies in the field of complex systems have generated new perspectives on management in social organizations such as hospitals. Much of this research appears as a natural extension of the cross-disciplinary field of systems theory. This is the 15th in a series of articles applying complex systems science to the traditional management concepts of planning, organizing, directing, coordinating, and controlling. In this article, the authors discuss healthcare social networks as a hierarchy of embedded complex adaptive systems. The authors further examine the use of social network analysis tools as a means to understand complex communication patterns and reduce medical errors.

  20. The Deep Space Network Advanced Systems Program

    NASA Technical Reports Server (NTRS)

    Davarian, Faramaz

    2010-01-01

    The deep space network (DSN)--with its three complexes in Goldstone, California, Madrid, Spain, and Canberra, Australia--provides the resources to track and communicate with planetary and deep space missions. Each complex consists of an array of capabilities for tracking probes almost anywhere in the solar system. A number of innovative hardware, software and procedural tools are used for day-to-day operations at DSN complexes as well as at the network control at the Jet Propulsion Laboratory (JPL). Systems and technologies employed by the network include large-aperture antennas (34-m and 70-m), cryogenically cooled receivers, high-power transmitters, stable frequency and timing distribution assemblies, modulation and coding schemes, spacecraft transponders, radiometric tracking techniques, etc. The DSN operates at multiple frequencies, including the 2-GHz band, the 7/8-GHz band, and the 32/34-GHz band.

  1. Networked Training: An Electronic Education System.

    ERIC Educational Resources Information Center

    Ryan, William J.

    1993-01-01

    Presents perspectives on networked training based on the development of an electronic education system at the Westinghouse Savannah River Company that integrated motion video, text, and data information with multiple audio sources. The technology options of compact disc, digital video architecture, and digital video interactive are discussed. (LRW)

  2. Distributing Executive Information Systems through Networks.

    ERIC Educational Resources Information Center

    Penrod, James I.; And Others

    1993-01-01

    Many colleges and universities will soon adopt distributed systems for executive information and decision support. Distribution of shared information through computer networks will improve decision-making processes dramatically on campuses. Critical success factors include administrative support, favorable organizational climate, ease of use,…

  3. Controllable Buoys and Networked Buoy Systems

    NASA Technical Reports Server (NTRS)

    Davoodi, Faranak (Inventor); Davoudi, Farhooman (Inventor)

    2017-01-01

    Buoyant sensor networks are described, comprising floating buoys with sensors and energy harvesting capabilities. The buoys can control their buoyancy and motion, and can organize communication in a distributed fashion. Some buoys may have tethered underwater vehicles with a smart spooling system that allows the vehicles to dive deep underwater while remaining in communication and connection with the buoys.

  4. Network and adaptive system of systems modeling and analysis.

    SciTech Connect

    Lawton, Craig R.; Campbell, James E. Dr.; Anderson, Dennis James; Eddy, John P.

    2007-05-01

    This report documents the results of an LDRD program entitled ''Network and Adaptive System of Systems Modeling and Analysis'' that was conducted during FY 2005 and FY 2006. The purpose of this study was to determine and implement ways to incorporate network communications modeling into existing System of Systems (SoS) modeling capabilities. Current SoS modeling, particularly for the Future Combat Systems (FCS) program, is conducted under the assumption that communication between the various systems is always possible and occurs instantaneously. A more realistic representation of these communications allows for better, more accurate simulation results. The current approach to meeting this objective has been to use existing capabilities to model network hardware reliability and adding capabilities to use that information to model the impact on the sustainment supply chain and operational availability.

  5. Hardware and Software Design of FPGA-based PCIe Gen3 interface for APEnet+ network interconnect system

    NASA Astrophysics Data System (ADS)

    Ammendola, R.; Biagioni, A.; Frezza, O.; Lo Cicero, F.; Lonardo, A.; Martinelli, M.; Paolucci, P. S.; Pastorelli, E.; Rossetti, D.; Simula, F.; Tosoratto, L.; Vicini, P.

    2015-12-01

    In the attempt to develop an interconnection architecture optimized for hybrid HPC systems dedicated to scientific computing, we designed APEnet+, a point-to-point, low-latency and high-performance network controller supporting 6 fully bidirectional off-board links over a 3D torus topology. The first release of APEnet+ (named V4) was a board based on a 40 nm Altera FPGA, integrating 6 channels at 34 Gbps of raw bandwidth per direction and a PCIe Gen2 x8 host interface. It has been the first-of-its-kind device to implement an RDMA protocol to directly read/write data from/to Fermi and Kepler NVIDIA GPUs using NVIDIA peer-to-peer and GPUDirect RDMA protocols, obtaining real zero-copy GPU-to-GPU transfers over the network. The latest generation of APEnet+ systems (now named V5) implements a PCIe Gen3 x8 host interface on a 28 nm Altera Stratix V FPGA, with multi-standard fast transceivers (up to 14.4 Gbps) and an increased amount of configurable internal resources and hardware IP cores to support main interconnection standard protocols. Herein we present the APEnet+ V5 architecture, the status of its hardware and its system software design. Both its Linux Device Driver and the low-level libraries have been redeveloped to support the PCIe Gen3 protocol, introducing optimizations and solutions based on hardware/software co-design.

  6. Threats to Networked RFID Systems

    NASA Astrophysics Data System (ADS)

    Mitrokotsa, Aikaterini; Beye, Michael; Peris-Lopez, Pedro

    RFID technology is an area currently undergoing active development. An issue, which has received a lot of attention, is the security risks that arise due to the inherent vulnerabilities of RFID technology. Most of this attention, however, has focused on related privacy issues. The goal of this chapter is to present a more global overview of RFID threats. This can not only help experts perform risk analyses of RFID systems but also increase awareness and understanding of RFID security issues for non-experts. We use clearly defined and widely accepted concepts from both the RFID area and classical risk analysis to structure this overview.

  7. A Calculator Controlled Microwave Network Analyzer System.

    DTIC Science & Technology

    1977-03-01

    A Hewlett Packard 8410S (Option 310) Microwave Network Analyzer System and the input/output interface to a Wang 600-14 Programmable Calculator are described. The original design of a digital to analog interface between the Wang 600-14 Calculator and a HP 8690B Sweep Oscillator is presented. Two system software programs which implement automatic S-parameter data collection and either external data storage or data reduction and display are described and documented. (Author)

  8. Enhancements to the Sentinel Fireball Network Video Software

    NASA Astrophysics Data System (ADS)

    Watson, Wayne

    2009-05-01

    The Sentinel Fireball Network that supports meteor imaging of bright meteors (fireballs) has been in existence for over ten years. Nearly five years ago it moved from gathering meteor data with a camera and VCR video tape to a fisheye lens attached to a hardware device, the Sentinel box, which allowed meteor data to be recorded on a PC operating under real-time Linux. In 2006, that software, sentuser, was made available on Apple, Linux, and Window operating systems using the Python computer language. It provides basic video and management functionality and a small amount of analytic software capability. This paper describes the new and attractive future features of the software, and, additionally, it reviews some of the research and networks from the past and present using video equipment to collect and analyze fireball data that have applicability to sentuser.

  9. Networks for Autonomous Formation Flying Satellite Systems

    NASA Technical Reports Server (NTRS)

    Knoblock, Eric J.; Konangi, Vijay K.; Wallett, Thomas M.; Bhasin, Kul B.

    2001-01-01

    The performance of three communications networks to support autonomous multi-spacecraft formation flying systems is presented. All systems are comprised of a ten-satellite formation arranged in a star topology, with one of the satellites designated as the central or "mother ship." All data is routed through the mother ship to the terrestrial network. The first system uses a TCP/lP over ATM protocol architecture within the formation the second system uses the IEEE 802.11 protocol architecture within the formation and the last system uses both of the previous architectures with a constellation of geosynchronous satellites serving as an intermediate point-of-contact between the formation and the terrestrial network. The simulations consist of file transfers using either the File Transfer Protocol (FTP) or the Simple Automatic File Exchange (SAFE) Protocol. The results compare the IF queuing delay, and IP processing delay at the mother ship as well as application-level round-trip time for both systems, In all cases, using IEEE 802.11 within the formation yields less delay. Also, the throughput exhibited by SAFE is better than FTP.

  10. Reaction networks and kinetics of biochemical systems.

    PubMed

    Arceo, Carlene Perpetua P; Jose, Editha C; Lao, Angelyn R; Mendoza, Eduardo R

    2017-01-01

    This paper further develops the connection between Chemical Reaction Network Theory (CRNT) and Biochemical Systems Theory (BST) that we recently introduced [1]. We first use algebraic properties of kinetic sets to study the set of complex factorizable kinetics CFK(N) on a CRN, which shares many characteristics with its subset of mass action kinetics. In particular, we extend the Theorem of Feinberg-Horn [9] on the coincidence of the kinetic and stoichiometric subsets of a mass action system to CF kinetics, using the concept of span surjectivity. We also introduce the branching type of a network, which determines the availability of kinetics on it and allows us to characterize the networks for which all kinetics are complex factorizable: A "Kinetics Landscape" provides an overview of kinetics sets, their algebraic properties and containment relationships. We then apply our results and those (of other CRNT researchers) reviewed in [1] to fifteen BST models of complex biological systems and discover novel network and kinetic properties that so far have not been widely studied in CRNT. In our view, these findings show an important benefit of connecting CRNT and BST modeling efforts.

  11. GAS MAIN SENSOR AND COMMUNICATIONS NETWORK SYSTEM

    SciTech Connect

    Hagen Schempf, Ph.D.

    2003-02-27

    Automatika, Inc. was contracted by the Department of Energy (DOE) and with co-funding from the New York Gas Group (NYGAS), to develop an in-pipe natural gas prototype measurement and wireless communications system for assessing and monitoring distribution networks. A prototype system was built for low-pressure cast-iron mains and tested in a spider- and serial-network configuration in a live network in Long Island with the support of Keyspan Energy, Inc. The prototype unit combined sensors capable of monitoring pressure, flow, humidity, temperature and vibration, which were sampled and combined in data-packages in an in-pipe master-slave architecture to collect data from a distributed spider-arrangement, and in a master-repeater-slave configuration in serial or ladder-network arrangements. It was found that the system was capable of performing all data-sampling and collection as expected, yielding interesting results as to flow-dynamics and vibration-detection. Wireless in-pipe communications were shown to be feasible and valuable data was collected in order to determine how to improve on range and data-quality in the future.

  12. Architecture for networked electronic patient record systems.

    PubMed

    Takeda, H; Matsumura, Y; Kuwata, S; Nakano, H; Sakamoto, N; Yamamoto, R

    2000-11-01

    There have been two major approaches to the development of networked electronic patient record (EPR) architecture. One uses object-oriented methodologies for constructing the model, which include the GEHR project, Synapses, HL7 RIM and so on. The second approach uses document-oriented methodologies, as applied in examples of HL7 PRA. It is practically beneficial to take the advantages of both approaches and to add solution technologies for network security such as PKI. In recognition of the similarity with electronic commerce, a certificate authority as a trusted third party will be organised for establishing networked EPR system. This paper describes a Japanese functional model that has been developed, and proposes a document-object-oriented architecture, which is-compared with other existing models.

  13. Gas Main Sensor and Communications Network System

    SciTech Connect

    Hagen Schempf

    2006-05-31

    Automatika, Inc. was contracted by the Department of Energy (DOE) and with co-funding from the Northeast Gas Association (NGA), to develop an in-pipe natural gas prototype measurement and wireless communications system for assessing and monitoring distribution networks. This projected was completed in April 2006, and culminated in the installation of more than 2 dozen GasNet nodes in both low- and high-pressure cast-iron and steel mains owned by multiple utilities in the northeastern US. Utilities are currently logging data (off-line) and monitoring data in real time from single and multiple networked sensors over cellular networks and collecting data using wireless bluetooth PDA systems. The system was designed to be modular, using in-pipe sensor-wands capable of measuring, flow, pressure, temperature, water-content and vibration. Internal antennae allowed for the use of the pipe-internals as a waveguide for setting up a sensor network to collect data from multiple nodes simultaneously. Sensor nodes were designed to be installed with low- and no-blow techniques and tools. Using a multi-drop bus technique with a custom protocol, all electronics were designed to be buriable and allow for on-board data-collection (SD-card), wireless relaying and cellular network forwarding. Installation options afforded by the design included direct-burial and external polemounted variants. Power was provided by one or more batteries, direct AC-power (Class I Div.2) and solar-array. The utilities are currently in a data-collection phase and intend to use the collected (and processed) data to make capital improvement decisions, compare it to Stoner model predictions and evaluate the use of such a system for future expansion, technology-improvement and commercialization starting later in 2006.

  14. Establishing Linux Clusters for High-Performance Computing (HPC) at NPS

    DTIC Science & Technology

    2004-09-01

    pygtk is needed by bps-1.2-11 gnuplot is needed by bps-1.2-11 [cdaillid@frontend-0 cdaillid]$ It can be ascertained from the above...message that the pygtk and gnuplot are missing from this system and that they are required by the BPS. All these RPMs can be found at http...regular expression pattern) is a useful find tool for the Unix Linux world. [cdaillid@frontend-0 /]$ rpm -qa | grep gnuplot [cdaillid@frontend-0

  15. Secured network sensor-based defense system

    NASA Astrophysics Data System (ADS)

    Wei, Sixiao; Shen, Dan; Ge, Linqiang; Yu, Wei; Blasch, Erik P.; Pham, Khanh D.; Chen, Genshe

    2015-05-01

    Network sensor-based defense (NSD) systems have been widely used to defend against cyber threats. Nonetheless, if the adversary finds ways to identify the location of monitor sensors, the effectiveness of NSD systems can be reduced. In this paper, we propose both temporal and spatial perturbation based defense mechanisms to secure NSD systems and make the monitor sensor invisible to the adversary. The temporal-perturbation based defense manipulates the timing information of published data so that the probability of successfully recognizing monitor sensors can be reduced. The spatial-perturbation based defense dynamically redeploys monitor sensors in the network so that the adversary cannot obtain the complete information to recognize all of the monitor sensors. We carried out experiments using real-world traffic traces to evaluate the effectiveness of our proposed defense mechanisms. Our data shows that our proposed defense mechanisms can reduce the attack accuracy of recognizing detection sensors.

  16. Systems approaches to the networks of aging.

    PubMed

    Kriete, Andres; Sokhansanj, Bahrad A; Coppock, Donald L; West, Geoffrey B

    2006-11-01

    The aging of an organism is the result of complex changes in structure and function of molecules, cells, tissues, and whole body systems. To increase our understanding of how aging works, we have to analyze and integrate quantitative evidence from multiple levels of biological organization. Here, we define a broader conceptual framework for a quantitative, computational systems biology approach to aging. Initially, we consider fractal supply networks that give rise to scaling laws relating body mass, metabolism and lifespan. This approach provides a top-down view of constrained cellular processes. Concomitantly, multi-omics data generation build such a framework from the bottom-up, using modeling strategies to identify key pathways and their physiological capacity. Multiscale spatio-temporal representations finally connect molecular processes with structural organization. As aging manifests on a systems level, it emerges as a highly networked process regulated through feedback loops between levels of biological organization.

  17. GAS MAIN SENSOR AND COMMUNICATIONS NETWORK SYSTEM

    SciTech Connect

    Hagen Schempf

    2004-09-30

    Automatika, Inc. was contracted by the Department of Energy (DOE) and with co-funding from the New York Gas Group (NYGAS), to develop an in-pipe natural gas prototype measurement and wireless communications system for assessing and monitoring distribution networks. In Phase II of this three-phase program, an improved prototype system was built for low-pressure cast-iron and high-pressure steel (including a no-blow installation system) mains and tested in a serial-network configuration in a live network in Long Island with the support of Keyspan Energy, Inc. The experiment was carried out in several open-hole excavations over a multi-day period. The prototype units (3 total) combined sensors capable of monitoring pressure, flow, humidity, temperature and vibration, which were sampled and combined in data-packages in an in-pipe master-repeater-slave configuration in serial or ladder-network arrangements. It was verified that the system was capable of performing all data-sampling, data-storage and collection as expected, yielding interesting results as to flow-dynamics and vibration-detection. Wireless in-pipe communications were shown to be feasible and the system was demonstrated to run off in-ground battery- and above-ground solar power. The remote datalogger access and storage-card features were demonstrated and used to log and post-process system data. Real-time data-display on an updated Phase-I GUI was used for in-field demonstration and troubleshooting.

  18. IEEE 342 Node Low Voltage Networked Test System

    SciTech Connect

    Schneider, Kevin P.; Phanivong, Phillippe K.; Lacroix, Jean-Sebastian

    2014-07-31

    The IEEE Distribution Test Feeders provide a benchmark for new algorithms to the distribution analyses community. The low voltage network test feeder represents a moderate size urban system that is unbalanced and highly networked. This is the first distribution test feeder developed by the IEEE that contains unbalanced networked components. The 342 node Low Voltage Networked Test System includes many elements that may be found in a networked system: multiple 13.2kV primary feeders, network protectors, a 120/208V grid network, and multiple 277/480V spot networks. This paper presents a brief review of the history of low voltage networks and how they evolved into the modern systems. This paper will then present a description of the 342 Node IEEE Low Voltage Network Test System and power flow results.

  19. Digital Video Over Space Systems and Networks

    NASA Technical Reports Server (NTRS)

    Grubbs, Rodney

    2010-01-01

    This slide presentation reviews the use of digital video with space systems and networks. The earliest use of video was the use of film precluding live viewing, which gave way to live television from space. This has given way to digital video using internet protocol for transmission. This has provided for many improvements with new challenges. Some of these ehallenges are reviewed. The change to digital video transmitted over space systems can provide incredible imagery, however the process must be viewed as an entire system, rather than piece-meal.

  20. Conceptualizing and Advancing Research Networking Systems

    PubMed Central

    SCHLEYER, TITUS; BUTLER, BRIAN S.; SONG, MEI; SPALLEK, HEIKO

    2013-01-01

    Science in general, and biomedical research in particular, is becoming more collaborative. As a result, collaboration with the right individuals, teams, and institutions is increasingly crucial for scientific progress. We propose Research Networking Systems (RNS) as a new type of system designed to help scientists identify and choose collaborators, and suggest a corresponding research agenda. The research agenda covers four areas: foundations, presentation, architecture, and evaluation. Foundations includes project-, institution- and discipline-specific motivational factors; the role of social networks; and impression formation based on information beyond expertise and interests. Presentation addresses representing expertise in a comprehensive and up-to-date manner; the role of controlled vocabularies and folksonomies; the tension between seekers’ need for comprehensive information and potential collaborators’ desire to control how they are seen by others; and the need to support serendipitous discovery of collaborative opportunities. Architecture considers aggregation and synthesis of information from multiple sources, social system interoperability, and integration with the user’s primary work context. Lastly, evaluation focuses on assessment of collaboration decisions, measurement of user-specific costs and benefits, and how the large-scale impact of RNS could be evaluated with longitudinal and naturalistic methods. We hope that this article stimulates the human-computer interaction, computer-supported cooperative work, and related communities to pursue a broad and comprehensive agenda for developing research networking systems. PMID:24376309

  1. System/360 Computer Assisted Network Scheduling (CANS) System

    NASA Technical Reports Server (NTRS)

    Brewer, A. C.

    1972-01-01

    Computer assisted scheduling techniques that produce conflict-free and efficient schedules have been developed and implemented to meet needs of the Manned Space Flight Network. CANS system provides effective management of resources in complex scheduling environment. System is automated resource scheduling, controlling, planning, information storage and retrieval tool.

  2. An algorithm of a real time image tracking system using a camera with pan/tilt motors on an embedded system

    NASA Astrophysics Data System (ADS)

    Kim, Hie-Sik; Nam, Chul; Ha, Kwan-Yong; Ayurzana, Odgeral; Kwon, Jong-Won

    2005-12-01

    The embedded systems have been applied to many fields, including households and industrial sites. The user interface technology with simple display on the screen was implemented more and more. The user demands are increasing and the system has more various applicable fields due to a high penetration rate of the Internet. Therefore, the demand for embedded system is tend to rise. An embedded system for image tracking was implemented. This system is used a fixed IP for the reliable server operation on TCP/IP networks. Using an USB camera on the embedded Linux system developed a real time broadcasting of video image on the Internet. The digital camera is connected at the USB host port of the embedded board. All input images from the video camera are continuously stored as a compressed JPEG file in a directory at the Linux web-server. And each frame image data from web camera is compared for measurement of displacement Vector. That used Block matching algorithm and edge detection algorithm for past speed. And the displacement vector is used at pan/tilt motor control through RS232 serial cable. The embedded board utilized the S3C2410 MPU, which used the ARM 920T core form Samsung. The operating system was ported to embedded Linux kernel and mounted of root file system. And the stored images are sent to the client PC through the web browser. It used the network function of Linux and it developed a program with protocol of the TCP/IP.

  3. Multi-agent tasks scheduling system in software defined networks

    NASA Astrophysics Data System (ADS)

    Skobelev, P. O.; Granichin, O. N.; Budaev, D. S.; Laryukhin, V. B.; Mayorov, I. V.

    2014-05-01

    In this paper a multi-agent tasks scheduling system in software defined networks is considered. This system is designed for distribution simulation and tasks implementation on computational resources including network dynamic characteristics and topology.

  4. System and method for networking electrochemical devices

    DOEpatents

    Williams, Mark C.; Wimer, John G.; Archer, David H.

    1995-01-01

    An improved electrochemically active system and method including a plurality of electrochemical devices, such as fuel cells and fluid separation devices, in which the anode and cathode process-fluid flow chambers are connected in fluid-flow arrangements so that the operating parameters of each of said plurality of electrochemical devices which are dependent upon process-fluid parameters may be individually controlled to provide improved operating efficiency. The improvements in operation include improved power efficiency and improved fuel utilization in fuel cell power generating systems and reduced power consumption in fluid separation devices and the like through interstage process fluid parameter control for series networked electrochemical devices. The improved networking method includes recycling of various process flows to enhance the overall control scheme.

  5. The realization of network video monitoring system

    NASA Astrophysics Data System (ADS)

    Hou, Zhuo-wei; Qiu, Yue-hong

    2013-08-01

    The paper presents a network video monitoring system based on field programmable gate array to implement the real time acquisition and transmission of video signals. The system includes image acquisition module, central control module and Ethernet transmission module. According to request, Cyclone FPGA is taken as the control center in the system, using Quartus II and Nios II IDE as development tool to build the hardware development platform. A kind of embedded hardware system is built based on SOPC technic, in which the Nios II soft-core and other controllers are combined by configuration. Meanwhile, the μClinux is used as embedded operating system to make the process of acquisition and transmission of the data picture on the Internet more reliable. In order to fulfill the task of MAC and PHY, the fast Ethernet controller should be connected to the SOPC. TCP/IP protocol is used to implement data transmission. Based on TCP/IP protocol, the Web Servers should be embedded to implement the protocol of HTTP, TCP and UDP. Through the research of the thesis, with programmable logic device being the core and network being the transmission media, the design scheme of the video monitoring system is presented. The hardware's design is mainly done in the thesis. The principal and function of the system is deeply explained, so it can be the important technology and specific method.

  6. Network Penetration Testing and Research

    NASA Technical Reports Server (NTRS)

    Murphy, Brandon F.

    2013-01-01

    This paper will focus the on research and testing done on penetrating a network for security purposes. This research will provide the IT security office new methods of attacks across and against a company's network as well as introduce them to new platforms and software that can be used to better assist with protecting against such attacks. Throughout this paper testing and research has been done on two different Linux based operating systems, for attacking and compromising a Windows based host computer. Backtrack 5 and BlackBuntu (Linux based penetration testing operating systems) are two different "attacker'' computers that will attempt to plant viruses and or NASA USRP - Internship Final Report exploits on a host Windows 7 operating system, as well as try to retrieve information from the host. On each Linux OS (Backtrack 5 and BlackBuntu) there is penetration testing software which provides the necessary tools to create exploits that can compromise a windows system as well as other operating systems. This paper will focus on two main methods of deploying exploits 1 onto a host computer in order to retrieve information from a compromised system. One method of deployment for an exploit that was tested is known as a "social engineering" exploit. This type of method requires interaction from unsuspecting user. With this user interaction, a deployed exploit may allow a malicious user to gain access to the unsuspecting user's computer as well as the network that such computer is connected to. Due to more advance security setting and antivirus protection and detection, this method is easily identified and defended against. The second method of exploit deployment is the method mainly focused upon within this paper. This method required extensive research on the best way to compromise a security enabled protected network. Once a network has been compromised, then any and all devices connected to such network has the potential to be compromised as well. With a compromised

  7. Cooperative Multi-Agent Systems in Mobile Ad Hoc Networks

    DTIC Science & Technology

    2006-01-01

    COOPERATIVE MULTI - AGENT SYSTEMS IN MOBILE AD HOC NETWORKS Joseph P. Macker William Chao Myriam Abramson Ian Downard Information Technology Division...are, mobile ad hoc networking (MANET) and Multi - Agent Systems (MAS). Despite their value in enabling more autonomous network system operation...2006 to 00-00-2006 4. TITLE AND SUBTITLE Cooperative Multi - Agent Systems in Mobile Ad Hoc Networks 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c

  8. Credit Default Swaps networks and systemic risk.

    PubMed

    Puliga, Michelangelo; Caldarelli, Guido; Battiston, Stefano

    2014-11-04

    Credit Default Swaps (CDS) spreads should reflect default risk of the underlying corporate debt. Actually, it has been recognized that CDS spread time series did not anticipate but only followed the increasing risk of default before the financial crisis. In principle, the network of correlations among CDS spread time series could at least display some form of structural change to be used as an early warning of systemic risk. Here we study a set of 176 CDS time series of financial institutions from 2002 to 2011. Networks are constructed in various ways, some of which display structural change at the onset of the credit crisis of 2008, but never before. By taking these networks as a proxy of interdependencies among financial institutions, we run stress-test based on Group DebtRank. Systemic risk before 2008 increases only when incorporating a macroeconomic indicator reflecting the potential losses of financial assets associated with house prices in the US. This approach indicates a promising way to detect systemic instabilities.

  9. Credit Default Swaps networks and systemic risk

    NASA Astrophysics Data System (ADS)

    Puliga, Michelangelo; Caldarelli, Guido; Battiston, Stefano

    2014-11-01

    Credit Default Swaps (CDS) spreads should reflect default risk of the underlying corporate debt. Actually, it has been recognized that CDS spread time series did not anticipate but only followed the increasing risk of default before the financial crisis. In principle, the network of correlations among CDS spread time series could at least display some form of structural change to be used as an early warning of systemic risk. Here we study a set of 176 CDS time series of financial institutions from 2002 to 2011. Networks are constructed in various ways, some of which display structural change at the onset of the credit crisis of 2008, but never before. By taking these networks as a proxy of interdependencies among financial institutions, we run stress-test based on Group DebtRank. Systemic risk before 2008 increases only when incorporating a macroeconomic indicator reflecting the potential losses of financial assets associated with house prices in the US. This approach indicates a promising way to detect systemic instabilities.

  10. Credit Default Swaps networks and systemic risk

    PubMed Central

    Puliga, Michelangelo; Caldarelli, Guido; Battiston, Stefano

    2014-01-01

    Credit Default Swaps (CDS) spreads should reflect default risk of the underlying corporate debt. Actually, it has been recognized that CDS spread time series did not anticipate but only followed the increasing risk of default before the financial crisis. In principle, the network of correlations among CDS spread time series could at least display some form of structural change to be used as an early warning of systemic risk. Here we study a set of 176 CDS time series of financial institutions from 2002 to 2011. Networks are constructed in various ways, some of which display structural change at the onset of the credit crisis of 2008, but never before. By taking these networks as a proxy of interdependencies among financial institutions, we run stress-test based on Group DebtRank. Systemic risk before 2008 increases only when incorporating a macroeconomic indicator reflecting the potential losses of financial assets associated with house prices in the US. This approach indicates a promising way to detect systemic instabilities. PMID:25366654

  11. Pathways, Networks and Systems Medicine Conferences

    SciTech Connect

    Nadeau, Joseph H.

    2013-11-25

    The 6th Pathways, Networks and Systems Medicine Conference was held at the Minoa Palace Conference Center, Chania, Crete, Greece (16-21 June 2008). The Organizing Committee was composed of Joe Nadeau (CWRU, Cleveland), Rudi Balling (German Research Centre, Brauschweig), David Galas (Institute for Systems Biology, Seattle), Lee Hood (Institute for Systems Biology, Seattle), Diane Isonaka (Seattle), Fotis Kafatos (Imperial College, London), John Lambris (Univ. Pennsylvania, Philadelphia),Harris Lewin (Univ. of Indiana, Urbana-Champaign), Edison Liu (Genome Institute of Singapore, Singapore), and Shankar Subramaniam (Univ. California, San Diego). A total of 101 individuals from 21 countries participated in the conference: USA (48), Canada (5), France (5), Austria (4), Germany (3), Italy (3), UK (3), Greece (2), New Zealand (2), Singapore (2), Argentina (1), Australia (1), Cuba (1), Denmark (1), Japan (1), Mexico (1), Netherlands (1), Spain (1), Sweden (1), Switzerland (1). With respect to speakers, 29 were established faculty members and 13 were graduate students or postdoctoral fellows. With respect to gender representation, among speakers, 13 were female and 28 were male, and among all participants 43 were female and 58 were male. Program these included the following topics: Cancer Pathways and Networks (Day 1), Metabolic Disease Networks (Day 2), Day 3 ? Organs, Pathways and Stem Cells (Day 3), and Day 4 ? Inflammation, Immunity, Microbes and the Environment (Day 4). Proceedings of the Conference were not published.

  12. Deep Space Network information system architecture study

    NASA Technical Reports Server (NTRS)

    Beswick, C. A.; Markley, R. W. (Editor); Atkinson, D. J.; Cooper, L. P.; Tausworthe, R. C.; Masline, R. C.; Jenkins, J. S.; Crowe, R. A.; Thomas, J. L.; Stoloff, M. J.

    1992-01-01

    The purpose of this article is to describe an architecture for the Deep Space Network (DSN) information system in the years 2000-2010 and to provide guidelines for its evolution during the 1990s. The study scope is defined to be from the front-end areas at the antennas to the end users (spacecraft teams, principal investigators, archival storage systems, and non-NASA partners). The architectural vision provides guidance for major DSN implementation efforts during the next decade. A strong motivation for the study is an expected dramatic improvement in information-systems technologies, such as the following: computer processing, automation technology (including knowledge-based systems), networking and data transport, software and hardware engineering, and human-interface technology. The proposed Ground Information System has the following major features: unified architecture from the front-end area to the end user; open-systems standards to achieve interoperability; DSN production of level 0 data; delivery of level 0 data from the Deep Space Communications Complex, if desired; dedicated telemetry processors for each receiver; security against unauthorized access and errors; and highly automated monitor and control.

  13. Stabilization and synchronization of networked mechanical systems

    NASA Astrophysics Data System (ADS)

    Nair, Sujit S.

    The main theme of this thesis is coordination and stabilization of a network of mechanical systems or rigid bodies to achieve synchronized behaviour. The idea is to use controls derived from potentials to couple the systems such that the closed-loop system is also a mechanical system with a Lagrangian structure. This permits the closed-loop Hamiltonian to be used as a Lyapunov function for stability analysis. It is a big challenge to develop a provable, systematic methodology to control and coordinate a network of systems to perform a given task. The control law should be robust enough to handle environment uncertainties, avoid obstacles and collisions and keep the system formation going. The fact that these systems may even have unstable dynamics makes the problem even more interesting and exciting both from a theoretical and applied point of view. This work investigates the coordination problem when each individual system has its own (maybe unstable) dynamics; this distinguishes this work from many other recent works on coordination control where the individual system dynamics are assumed to be single/double integrators. We build coordination techniques for three kinds of systems. The first one consists of underactuated Lagrangian systems with Abelian symmetry groups lacking gyroscopic forces. Asymptotic stabilization is proved for two cases, one which yields convergence to synchronized motion restricted to a constant momentum surface and one in which the system converges asymptotically to a relative equilibrium. Next we consider rigid body systems where the configuration space of each individual body is the non Abelian Lie group SO(3) or SE(3). In the SO(3) case, the asymptotically stabilized solution corresponds to each rigid body rotating about its unstable middle axis and all the bodies synchronized and pointing in a particular direction in inertial space. In the SE(3) case, the asymptotically stabilized solution corresponds to each rigid body rotating about

  14. Some queuing network models of computer systems

    NASA Technical Reports Server (NTRS)

    Herndon, E. S.

    1980-01-01

    Queuing network models of a computer system operating with a single workload type are presented. Program algorithms are adapted for use on the Texas Instruments SR-52 programmable calculator. By slightly altering the algorithm to process the G and H matrices row by row instead of column by column, six devices and an unlimited job/terminal population could be handled on the SR-52. Techniques are also introduced for handling a simple load dependent server and for studying interactive systems with fixed multiprogramming limits.

  15. A European Network for Earth System Modeling

    NASA Astrophysics Data System (ADS)

    Valcke, Sophie; Budich, Reinhard; Carter, Mick; Guilyardi, Eric; Foujols, Marie-Alice; Lautenschlager, Michael; Redler, René; Steenman-Clark, Lois; Wedi, Nils

    2007-03-01

    The increasing complexity of Earth system models and the computing facilities needed to run those models put a heavy technical burden on research teams active in climate modeling. To ease this burden, a European collaborative venture called PRISM was initiated in December 2001 to organize a network of experts in order to share the development, maintenance, and support of Earth system modeling software tools and community standards. PRISM was recently reorganized, and a new Web portal (http://prism.enes.org) was unveiled in July 2006.

  16. Functional Network Dynamics of the Language System

    PubMed Central

    Chai, Lucy R.; Mattar, Marcelo G.; Blank, Idan Asher; Fedorenko, Evelina; Bassett, Danielle S.

    2016-01-01

    During linguistic processing, a set of brain regions on the lateral surfaces of the left frontal, temporal, and parietal cortices exhibit robust responses. These areas display highly correlated activity while a subject rests or performs a naturalistic language comprehension task, suggesting that they form an integrated functional system. Evidence suggests that this system is spatially and functionally distinct from other systems that support high-level cognition in humans. Yet, how different regions within this system might be recruited dynamically during task performance is not well understood. Here we use network methods, applied to fMRI data collected from 22 human subjects performing a language comprehension task, to reveal the dynamic nature of the language system. We observe the presence of a stable core of brain regions, predominantly located in the left hemisphere, that consistently coactivate with one another. We also observe the presence of a more flexible periphery of brain regions, predominantly located in the right hemisphere, that coactivate with different regions at different times. However, the language functional ROIs in the angular gyrus and the anterior temporal lobe were notable exceptions to this trend. By highlighting the temporal dimension of language processing, these results suggest a trade-off between a region's specialization and its capacity for flexible network reconfiguration. PMID:27550868

  17. LIBRA: An inexpensive geodetic network densification system

    NASA Technical Reports Server (NTRS)

    Fliegel, H. F.; Gantsweg, M.; Callahan, P. S.

    1975-01-01

    A description is given of the Libra (Locations Interposed by Ranging Aircraft) system, by which geodesy and earth strain measurements can be performed rapidly and inexpensively to several hundred auxiliary points with respect to a few fundamental control points established by any other technique, such as radio interferometry or satellite ranging. This low-cost means of extending the accuracy of space age geodesy to local surveys provides speed and spatial resolution useful, for example, for earthquake hazards estimation. Libra may be combined with an existing system, Aries (Astronomical Radio Interferometric Earth Surveying) to provide a balanced system adequate to meet the geophysical needs, and applicable to conventional surveying. The basic hardware design was outlined and specifications were defined. Then need for network densification was described. The following activities required to implement the proposed Libra system are also described: hardware development, data reduction, tropospheric calibrations, schedule of development and estimated costs.

  18. Evaluation of a Cyber Security System for Hospital Network.

    PubMed

    Faysel, Mohammad A

    2015-01-01

    Most of the cyber security systems use simulated data in evaluating their detection capabilities. The proposed cyber security system utilizes real hospital network connections. It uses a probabilistic data mining algorithm to detect anomalous events and takes appropriate response in real-time. On an evaluation using real-world hospital network data consisting of incoming network connections collected for a 24-hour period, the proposed system detected 15 unusual connections which were undetected by a commercial intrusion prevention system for the same network connections. Evaluation of the proposed system shows a potential to secure protected patient health information on a hospital network.

  19. A heterogeneous sensor network simulation system with integrated terrain data for real-time target detection in 3D space

    NASA Astrophysics Data System (ADS)

    Lin, Hong; Tanner, Steve; Rushing, John; Graves, Sara; Criswell, Evans

    2008-03-01

    Large scale sensor networks composed of many low-cost small sensors networked together with a small number of high fidelity position sensors can provide a robust, fast and accurate air defense and warning system. The team has been developing simulations of such large networks, and is now adding terrain data in an effort to provide more realistic analysis of the approach. This work, a heterogeneous sensor network simulation system with integrated terrain data for real-time target detection in a three-dimensional environment is presented. The sensor network can be composed of large numbers of low fidelity binary and bearing-only sensors, and small numbers of high fidelity position sensors, such as radars. The binary and bearing-only sensors are randomly distributed over a large geographic region; while the position sensors are distributed evenly. The elevations of the sensors are determined through the use of DTED Level 0 dataset. The targets are located through fusing measurement information from all types of sensors modeled by the simulation. The network simulation utilizes the same search-based optimization algorithm as in our previous two-dimensional sensor network simulation with some significant modifications. The fusion algorithm is parallelized using spatial decomposition approach: the entire surveillance area is divided into small regions and each region is assigned to one compute node. Each node processes sensor measurements and terrain data only for the assigned sub region. A master process combines the information from all the compute nodes to get the overall network state. The simulation results have indicated that the distributed fusion algorithm is efficient enough so that an optimal solution can be reached before the arrival of the next sensor data with a reasonable time interval, and real-time target detection can be achieved. The simulation was performed on a Linux cluster with communication between nodes facilitated by the Message Passing Interface

  20. Efficient Parallel Engineering Computing on Linux Workstations

    NASA Technical Reports Server (NTRS)

    Lou, John Z.

    2010-01-01

    A C software module has been developed that creates lightweight processes (LWPs) dynamically to achieve parallel computing performance in a variety of engineering simulation and analysis applications to support NASA and DoD project tasks. The required interface between the module and the application it supports is simple, minimal and almost completely transparent to the user applications, and it can achieve nearly ideal computing speed-up on multi-CPU engineering workstations of all operating system platforms. The module can be integrated into an existing application (C, C++, Fortran and others) either as part of a compiled module or as a dynamically linked library (DLL).

  1. Advanced systems engineering and network planning support

    NASA Technical Reports Server (NTRS)

    Walters, David H.; Barrett, Larry K.; Boyd, Ronald; Bazaj, Suresh; Mitchell, Lionel; Brosi, Fred

    1990-01-01

    The objective of this task was to take a fresh look at the NASA Space Network Control (SNC) element for the Advanced Tracking and Data Relay Satellite System (ATDRSS) such that it can be made more efficient and responsive to the user by introducing new concepts and technologies appropriate for the 1997 timeframe. In particular, it was desired to investigate the technologies and concepts employed in similar systems that may be applicable to the SNC. The recommendations resulting from this study include resource partitioning, on-line access to subsets of the SN schedule, fluid scheduling, increased use of demand access on the MA service, automating Inter-System Control functions using monitor by exception, increase automation for distributed data management and distributed work management, viewing SN operational control in terms of the OSI Management framework, and the introduction of automated interface management.

  2. Loss distribution of systemic defaults in different interbank networks

    NASA Astrophysics Data System (ADS)

    Li, Shouwei; He, Jianmin

    2016-04-01

    We analyze the impact of the network structure, the default probability and the loss given default (LGD) on the loss distribution of systemic defaults in the interbank market, where network structures analyzed include random networks, small-world networks and scale-free networks. We find that the network structure has little effect on the shape of the loss distribution, whereas the opposite is true to the default probability; the LGD changes the shape of the loss distribution significantly when default probabilities are high; the maximum of the possible loss is sensitive to the network structure and the LGD.

  3. Deep Space Network information system architecture study

    NASA Technical Reports Server (NTRS)

    Beswick, C. A.; Markley, R. W. (Editor); Atkinson, D. J.; Cooper, L. P.; Tausworthe, R. C.; Masline, R. C.; Jenkins, J. S.; Crowe, R. A.; Thomas, J. L.; Stoloff, M. J.

    1992-01-01

    The purpose of this article is to describe an architecture for the DSN information system in the years 2000-2010 and to provide guidelines for its evolution during the 1990's. The study scope is defined to be from the front-end areas at the antennas to the end users (spacecraft teams, principal investigators, archival storage systems, and non-NASA partners). The architectural vision provides guidance for major DSN implementation efforts during the next decade. A strong motivation for the study is an expected dramatic improvement in information-systems technologies--i.e., computer processing, automation technology (including knowledge-based systems), networking and data transport, software and hardware engineering, and human-interface technology. The proposed Ground Information System has the following major features: unified architecture from the front-end area to the end user; open-systems standards to achieve interoperability; DSN production of level 0 data; delivery of level 0 data from the Deep Space Communications Complex, if desired; dedicated telemetry processors for each receiver; security against unauthorized access and errors; and highly automated monitor and control.

  4. Networks.

    ERIC Educational Resources Information Center

    Maughan, George R.; Petitto, Karen R.; McLaughlin, Don

    2001-01-01

    Describes the connectivity features and options of modern campus communication and information system networks, including signal transmission (wire-based and wireless), signal switching, convergence of networks, and network assessment variables, to enable campus leaders to make sound future-oriented decisions. (EV)

  5. Implementation of Fuzzy Inference Systems Using Neural Network Techniques

    DTIC Science & Technology

    1992-03-01

    rules required to implement the system, which are usually supplied by ’experts’. One alternative is to use a neural network -type architecture to implement...the fuzzy inference system, and neural network -type training techniques to ’learn’ the control parameters needed by the fuzzy inference system. By...using a generalized version of a neural network , the rules of the fuzzy inference system can be learned without the assistance of experts.

  6. FTAP: a Linux-based program for tapping and music experiments.

    PubMed

    Finney, S A

    2001-02-01

    This paper describes FTAP, a flexible data collection system for tapping and music experiments. FTAP runs on standard PC hardware with the Linux operating system and can process input keystrokes and auditory output with reliable millisecond resolution. It uses standard MIDI devices for input and output and is particularly flexible in the area of auditory feedback manipulation. FTAP can run a wide variety of experiments, including synchronization/continuation tasks (Wing & Kristofferson, 1973), synchronization tasks combined with delayed auditory feedback (Aschersleben & Prinz, 1997), continuation tasks with isolated feedback perturbations (Wing, 1977), and complex alterations of feedback in music performance (Finney, 1997). Such experiments have often been implemented with custom hardware and software systems, but with FTAP they can be specified by a simple ASCII text parameter file. FTAP is available at no cost in source-code form.

  7. Transformation of legacy network management system to service oriented architecture

    NASA Astrophysics Data System (ADS)

    Sathyan, Jithesh; Shenoy, Krishnananda

    2007-09-01

    Service providers today are facing the challenge of operating and maintaining multiple networks, based on multiple technologies. Network Management System (NMS) solutions are being used to manage these networks. However the NMS is tightly coupled with Element or the Core network components. Hence there are multiple NMS solutions for heterogeneous networks. Current network management solutions are targeted at a variety of independent networks. The wide spread popularity of IP Multimedia Subsystem (IMS) is a clear indication that all of these independent networks will be integrated into a single IP-based infrastructure referred to as Next Generation Networks (NGN) in the near future. The services, network architectures and traffic pattern in NGN will dramatically differ from the current networks. The heterogeneity and complexity in NGN including concepts like Fixed Mobile Convergence will bring a number of challenges to network management. The high degree of complexity accompanying the network element technology necessitates network management systems (NMS) which can utilize this technology to provide more service interfaces while hiding the inherent complexity. As operators begin to add new networks and expand existing networks to support new technologies and products, the necessity of scalable, flexible and functionally rich NMS systems arises. Another important factor influencing NMS architecture is mergers and acquisitions among the key vendors. Ease of integration is a key impediment in the traditional hierarchical NMS architecture. These requirements trigger the need for an architectural framework that will address the NGNM (Next Generation Network Management) issues seamlessly. This paper presents a unique perspective of bringing service orientated architecture (SOA) to legacy network management systems (NMS). It advocates a staged approach in transforming a legacy NMS to SOA. The architecture at each stage is detailed along with the technical advantages and

  8. Consensus and Stability Analysis of Networked Multiagent Predictive Control Systems.

    PubMed

    Liu, Guo-Ping

    2016-03-17

    This paper is concerned with the consensus and stability problem of multiagent control systems via networks with communication delays and data loss. A networked multiagent predictive control scheme is proposed to achieve output consensus and also compensate for the communication delays and data loss actively. The necessary and sufficient conditions of achieving both consensus and stability of the closed-loop networked multiagent control systems are derived. An important result that is obtained is that the consensus and stability of closed-loop networked multiagent predictive control systems are not related to the communication delays and data loss. An example illustrates the performance of the networked multiagent predictive control scheme.

  9. International fixed satellite systems in synchronous digital hierarchy transport networks

    NASA Astrophysics Data System (ADS)

    Oei, W. S.; Tamboli, S.

    1992-10-01

    This paper discusses functional and architectural aspects and suitable networks scenarios for the integration of international fixed satellite systems, such as the INTELSAT system, in and between digital networks implementing the new CCITT synchronous digital hierarchy (SDH). The paper presents SDH transmission network functional requirements, and combines them with current and anticipated future FSS operational requirements. It is shown that integration permits the use of SDH functions and features for enhanced network service provisioning by FSS in the international network fabric, and leads to new FSS system design criteria.

  10. Neural network system for traffic flow management

    NASA Astrophysics Data System (ADS)

    Gilmore, John F.; Elibiary, Khalid J.; Petersson, L. E. Rickard

    1992-09-01

    Atlanta will be the home of several special events during the next five years ranging from the 1996 Olympics to the 1994 Super Bowl. When combined with the existing special events (Braves, Falcons, and Hawks games, concerts, festivals, etc.), the need to effectively manage traffic flow from surface streets to interstate highways is apparent. This paper describes a system for traffic event response and management for intelligent navigation utilizing signals (TERMINUS) developed at Georgia Tech for adaptively managing special event traffic flows in the Atlanta, Georgia area. TERMINUS (the original name given Atlanta, Georgia based upon its role as a rail line terminating center) is an intelligent surface street signal control system designed to manage traffic flow in Metro Atlanta. The system consists of three components. The first is a traffic simulation of the downtown Atlanta area around Fulton County Stadium that models the flow of traffic when a stadium event lets out. Parameters for the surrounding area include modeling for events during various times of day (such as rush hour). The second component is a computer graphics interface with the simulation that shows the traffic flows achieved based upon intelligent control system execution. The final component is the intelligent control system that manages surface street light signals based upon feedback from control sensors that dynamically adapt the intelligent controller's decision making process. The intelligent controller is a neural network model that allows TERMINUS to control the configuration of surface street signals to optimize the flow of traffic away from special events.

  11. Network versus portfolio structure in financial systems

    NASA Astrophysics Data System (ADS)

    Kobayashi, Teruyoshi

    2013-10-01

    The question of how to stabilize financial systems has attracted considerable attention since the global financial crisis of 2007-2009. Recently, Beale et al. [Proc. Natl. Acad. Sci. USA 108, 12647 (2011)] demonstrated that higher portfolio diversity among banks would reduce systemic risk by decreasing the risk of simultaneous defaults at the expense of a higher likelihood of individual defaults. In practice, however, a bank default has an externality in that it undermines other banks’ balance sheets. This paper explores how each of these different sources of risk, simultaneity risk and externality, contributes to systemic risk. The results show that the allocation of external assets that minimizes systemic risk varies with the topology of the financial network as long as asset returns have negative correlations. In the model, a well-known centrality measure, PageRank, reflects an appropriately defined “infectiveness” of a bank. An important result is that the most infective bank needs not always to be the safest bank. Under certain circumstances, the most infective node should act as a firewall to prevent large-scale collective defaults. The introduction of a counteractive portfolio structure will significantly reduce systemic risk.

  12. An expert system application for network intrusion detection

    SciTech Connect

    Jackson, K.A.; Dubois, D.H.; Stallings, C.A.

    1991-01-01

    The paper describes the design of a prototype intrusion detection system for the Los Alamos National Laboratory's Integrated Computing Network (ICN). The Network Anomaly Detection and Intrusion Reporter (NADIR) differs in one respect from most intrusion detection systems. It tries to address the intrusion detection problem on a network, as opposed to a single operating system. NADIR design intent was to copy and improve the audit record review activities normally done by security auditors. We wished to replace the manual review of audit logs with a near realtime expert system. NADIR compares network activity, as summarized in user profiles, against expert rules that define network security policy, improper or suspicious network activities, and normal network and user activity. When it detects deviant (anomalous) behavior, NADIR alerts operators in near realtime, and provides tools to aid in the investigation of the anomalous event. 15 refs., 2 figs.

  13. Stoichiometric network theory for nonequilibrium biochemical systems.

    PubMed

    Qian, Hong; Beard, Daniel A; Liang, Shou-dan

    2003-02-01

    We introduce the basic concepts and develop a theory for nonequilibrium steady-state biochemical systems applicable to analyzing large-scale complex isothermal reaction networks. In terms of the stoichiometric matrix, we demonstrate both Kirchhoff's flux law sigma(l)J(l)=0 over a biochemical species, and potential law sigma(l) mu(l)=0 over a reaction loop. They reflect mass and energy conservation, respectively. For each reaction, its steady-state flux J can be decomposed into forward and backward one-way fluxes J = J+ - J-, with chemical potential difference deltamu = RT ln(J-/J+). The product -Jdeltamu gives the isothermal heat dissipation rate, which is necessarily non-negative according to the second law of thermodynamics. The stoichiometric network theory (SNT) embodies all of the relevant fundamental physics. Knowing J and deltamu of a biochemical reaction, a conductance can be computed which directly reflects the level of gene expression for the particular enzyme. For sufficiently small flux a linear relationship between J and deltamu can be established as the linear flux-force relation in irreversible thermodynamics, analogous to Ohm's law in electrical circuits.

  14. System Leadership, Networks and the Question of Power

    ERIC Educational Resources Information Center

    Hatcher, Richard

    2008-01-01

    The author's argument revolves around the relationships between government agendas and the agency of teachers, and between them the intermediary role of management as "system leaders" of network forms. Network is a pluralistic concept: networks can serve very different educational-political interests. They offer the potential of new…

  15. CMA Member Survey: Network Management Systems Showing Little Improvement.

    ERIC Educational Resources Information Center

    Lusa, John M.

    1998-01-01

    Discusses results of a survey of 112 network and telecom managers--members of the Communications Managers Association (CMA)--to identify problems relating to the operation of large enterprise networks. Results are presented in a table under categories of: respondent profile; network management systems; carrier management; enterprise management;…

  16. A Linux cluster for between-pulse magnetic equilibrium reconstructions and other processor bound analyses

    SciTech Connect

    Peng, Q.; Groebner, R. J.; Lao, L. L.; Schachter, J.; Schissel, D. P.; Wade, M. R.

    2001-08-01

    A 12-processor Linux PC cluster has been installed to perform between-pulse magnetic equilibrium reconstructions during tokamak operations using the EFIT code written in FORTRAN. The MPICH package implementing message passing interface is employed by EFIT for data distribution and communication. The new system calculates equilibria eight times faster than the previous system yielding a complete equilibrium time history on a 25 ms time scale 4 min after the pulse ends. A graphical interface is provided for users to control the time resolution and the type of EFITs. The next analysis to benefit from the cluster is CERQUICK written in IDL for ion temperature profile analysis. The plan is to expand the cluster so that a full profile analysis (Te, Ti, ne, Vr, Zeff) can be made available between pulses, which lays the ground work for Kinetic EFIT and/or ONETWO power balance analyses.

  17. A Neural Network Based Speech Recognition System

    DTIC Science & Technology

    1990-02-01

    encoder and identifies individual words. This use of neural networks offers two advantages over conventional algorithmic detectors: the detection...environment. Keywords: Artificial intelligence; Neural networks : Back propagation; Speech recognition.

  18. System and method for generating a relationship network

    DOEpatents

    Franks, Kasian; Myers, Cornelia A.; Podowski, Raf M.

    2011-07-26

    A computer-implemented system and process for generating a relationship network is disclosed. The system provides a set of data items to be related and generates variable length data vectors to represent the relationships between the terms within each data item. The system can be used to generate a relationship network for documents, images, or any other type of file. This relationship network can then be queried to discover the relationships between terms within the set of data items.

  19. System and method for generating a relationship network

    DOEpatents

    Franks, Kasian; Myers, Cornelia A; Podowski, Raf M

    2015-05-05

    A computer-implemented system and process for generating a relationship network is disclosed. The system provides a set of data items to be related and generates variable length data vectors to represent the relationships between the terms within each data item. The system can be used to generate a relationship network for documents, images, or any other type of file. This relationship network can then be queried to discover the relationships between terms within the set of data items.

  20. A Case for Open Network Health Systems: Systems as Networks in Public Mental Health

    PubMed Central

    Rhodes, Michael Grant; de Vries, Marten W.

    2017-01-01

    Increases in incidents involving so-called confused persons have brought attention to the potential costs of recent changes to public mental health (PMH) services in the Netherlands. Decentralized under the (Community) Participation Act (2014), local governments must find resources to compensate for reduced central funding to such services or "innovate." But innovation, even when pressure for change is intense, is difficult. This perspective paper describes experience during and after an investigation into a particularly violent incident and murder. The aim was to provide recommendations to improve the functioning of local PMH services. The investigation concluded that no specific failure by an individual professional or service provider facility led to the murder. Instead, also as a result of the Participation Act that severed communication lines between individuals and organizations, information sharing failures were likely to have reduced system level capacity to identify risks. The methods and analytical frameworks employed to reach this conclusion, also lead to discussion as to the plausibility of an unconventional solution. If improving communication is the primary problem, non-hierarchical information, and organizational networks arise as possible and innovative system solutions. The proposal for debate is that traditional "health system" definitions, literature and narratives, and operating assumptions in public (mental) health are ‘locked in’ constraining technical and organization innovations. If we view a "health system" as an adaptive system of economic and social "networks," it becomes clear that the current orthodox solution, the so-called integrated health system, typically results in a "centralized hierarchical" or "tree" network. An overlooked alternative that breaks out of the established policy narratives is the view of a ‘health systems’ as a non-hierarchical organizational structure or ‘Open Network.’ In turn, this opens new

  1. Famine Early Warning System Network (FEWS NET)

    USGS Publications Warehouse

    Verdin, James P.

    2006-01-01

    The FEWS NET mission is to identify potentially food-insecure conditions early through the provision of timely and analytical hazard and vulnerability information. U.S. Government decision-makers act on this information to authorize mitigation and response activities. The U.S. Geological Survey (USGS) FEWS NET provides tools and data for monitoring and forecasting the incidence of drought and flooding to identify shocks to the food supply system that could lead to famine. Historically focused on Africa, the scope of the network has expanded to be global coverage. FEWS NET implementing partners include the USGS, National Aeronautics and Space Administration (NASA), National Oceanic and Atmospheric Administration (NOAA), United States Agency for International Development (USAID), United States Department of Agriculture (USDA), and Chemonics International.

  2. Stabilization of model-based networked control systems

    NASA Astrophysics Data System (ADS)

    Miranda, Francisco; Abreu, Carlos; Mendes, Paulo M.

    2016-06-01

    A class of networked control systems called Model-Based Networked Control Systems (MB-NCSs) is considered. Stabilization of MB-NCSs is studied using feedback controls and simulation of stabilization for different feedbacks is made with the purpose to reduce the network trafic. The feedback control input is applied in a compensated model of the plant that approximates the plant dynamics and stabilizes the plant even under slow network conditions. Conditions for global exponential stabilizability and for the choosing of a feedback control input for a given constant time between the information moments of the network are derived. An optimal control problem to obtain an optimal feedback control is also presented.

  3. DebtRank-transparency: Controlling systemic risk in financial networks

    PubMed Central

    Thurner, Stefan; Poledna, Sebastian

    2013-01-01

    Nodes in a financial network, such as banks, cannot assess the true risks associated with lending to other nodes in the network, unless they have full information on the riskiness of all other nodes. These risks can be estimated by using network metrics (as DebtRank) of the interbank liability network. With a simple agent based model we show that systemic risk in financial networks can be drastically reduced by increasing transparency, i.e. making the DebtRank of individual banks visible to others, and by imposing a rule, that reduces interbank borrowing from systemically risky nodes. This scheme does not reduce the efficiency of the financial network, but fosters a more homogeneous risk-distribution within the system in a self-organized critical way. The reduction of systemic risk is due to a massive reduction of cascading failures in the transparent system. A regulation-policy implementation of the proposed scheme is discussed. PMID:23712454

  4. A Comparison of Geographic Information Systems, Complex Networks, and Other Models for Analyzing Transportation Network Topologies

    NASA Technical Reports Server (NTRS)

    Alexandrov, Natalia (Technical Monitor); Kuby, Michael; Tierney, Sean; Roberts, Tyler; Upchurch, Christopher

    2005-01-01

    This report reviews six classes of models that are used for studying transportation network topologies. The report is motivated by two main questions. First, what can the "new science" of complex networks (scale-free, small-world networks) contribute to our understanding of transport network structure, compared to more traditional methods? Second, how can geographic information systems (GIS) contribute to studying transport networks? The report defines terms that can be used to classify different kinds of models by their function, composition, mechanism, spatial and temporal dimensions, certainty, linearity, and resolution. Six broad classes of models for analyzing transport network topologies are then explored: GIS; static graph theory; complex networks; mathematical programming; simulation; and agent-based modeling. Each class of models is defined and classified according to the attributes introduced earlier. The paper identifies some typical types of research questions about network structure that have been addressed by each class of model in the literature.

  5. The Network Information Management System (NIMS) in the Deep Space Network

    NASA Technical Reports Server (NTRS)

    Wales, K. J.

    1983-01-01

    In an effort to better manage enormous amounts of administrative, engineering, and management data that is distributed worldwide, a study was conducted which identified the need for a network support system. The Network Information Management System (NIMS) will provide the Deep Space Network with the tools to provide an easily accessible source of valid information to support management activities and provide a more cost-effective method of acquiring, maintaining, and retrieval data.

  6. Index : A Rule Based Expert System For Computer Network Maintenance

    NASA Astrophysics Data System (ADS)

    Chaganty, Srinivas; Pitchai, Anandhi; Morgan, Thomas W.

    1988-03-01

    Communications is an expert intensive discipline. The application of expert systems for maintenance of large and complex networks, mainly as an aid in trouble shooting, can simplify the task of network management. The important steps involved in troubleshooting are fault detection, fault reporting, fault interpretation and fault isolation. At present, Network Maintenance Facilities are capable of detecting and reporting the faults to network personnel. Fault interpretation refers to the next step in the process, which involves coming up with reasons for the failure. Fault interpretation can be characterized in two ways. First, it involves such a diversity of facts that it is difficult to predict. Secondly, it embodies a wealth of knowledge in the form of network management personnel. The application of expert systems in these interpretive tasks is an important step towards automation of network maintenance. In this paper, INDEX (Intelligent Network Diagnosis Expediter), a rule based production system for computer network alarm interpretation is described. It acts as an intelligent filter for people analyzing network alarms. INDEX analyzes the alarms in the network and identifies proper maintenance action to be taken.The important feature of this production system is that it is data driven. Working memory is the principal data repository of production systems and its contents represent the current state of the problem. Control is based upon which productions match the constantly changing working memory elements. Implementation of the prototype is in OPS83. Major issues in rule based system development such as rule base organization, implementation and efficiency are discussed.

  7. Systems biology of molecular chaperone networks.

    PubMed

    Csermely, Péter; Korcsmáros, Tamás; Kovács, István A; Szalay, Máté S; Soti, Csaba

    2008-01-01

    Molecular chaperones are not only fascinating molecular machines that help the folding, refolding, activation or assembly of other proteins, but also have a number of functions. These functions can be understood only by considering the emergent properties of cellular networks--and that of chaperones as special network constituents. As a notable example for the network-related roles of chaperones they may act as genetic buffers stabilizing the phenotype of various cells and organisms, and may serve as potential regulators of evolvability. Why are chaperones special in the context of cellular networks? Chaperones: (1) have weak links, i.e. low affinity, transient interactions with most of their partners; (2) connect hubs, i.e. act as 'masterminds' of the cell being close to several centre proteins with a lot of neighbours; and (3) are in the overlaps of network modules, which confers upon them a special regulatory role. Importantly, chaperones may uncouple or even quarantine modules of protein-protein interaction networks, signalling networks, genetic regulatory networks and membrane organelle networks during stress, which gives an additional chaperone-mediated protection for the cell at the network-level. Moreover, chaperones are essential to rebuild inter-modular contacts after stress by their low affinity, 'quasi-random' sampling of the potential interaction partners in different cellular modules. This opens the way to the chaperone-regulated modular evolution of cellular networks, and helps us to design novel therapeutic and anti-ageing strategies.

  8. Networking.

    ERIC Educational Resources Information Center

    Duvall, Betty

    Networking is an information giving and receiving system, a support system, and a means whereby women can get ahead in careers--either in new jobs or in current positions. Networking information can create many opportunities: women can talk about how other women handle situations and tasks, and previously established contacts can be used in…

  9. Neural Network Based Intelligent Sootblowing System

    SciTech Connect

    Mark Rhode

    2005-04-01

    , particulate matter is also a by-product of coal combustion. Modern day utility boilers are usually fitted with electrostatic precipitators to aid in the collection of particulate matter. Although extremely efficient, these devices are sensitive to rapid changes in inlet mass concentration as well as total mass loading. Traditionally, utility boilers are equipped with devices known as sootblowers, which use, steam, water or air to dislodge and clean the surfaces within the boiler and are operated based upon established rule or operator's judgment. Poor sootblowing regimes can influence particulate mass loading to the electrostatic precipitators. The project applied a neural network intelligent sootblowing system in conjunction with state-of-the-art controls and instruments to optimize the operation of a utility boiler and systematically control boiler slagging/fouling. This optimization process targeted reduction of NOx of 30%, improved efficiency of 2% and a reduction in opacity of 5%. The neural network system proved to be a non-invasive system which can readily be adapted to virtually any utility boiler. Specific conclusions from this neural network application are listed below. These conclusions should be used in conjunction with the specific details provided in the technical discussions of this report to develop a thorough understanding of the process.

  10. CFDP for Interplanetary Overlay Network

    NASA Technical Reports Server (NTRS)

    Burleigh, Scott C.

    2011-01-01

    The CCSDS (Consultative Committee for Space Data Systems) File Delivery Protocol for Interplanetary Overlay Network (CFDP-ION) is an implementation of CFDP that uses IO' s DTN (delay tolerant networking) implementation as its UT (unit-data transfer) layer. Because the DTN protocols effect automatic, reliable transmission via multiple relays, CFDP-ION need only satisfy the requirements for Class 1 ("unacknowledged") CFDP. This keeps the implementation small, but without loss of capability. This innovation minimizes processing resources by using zero-copy objects for file data transmission. It runs without modification in VxWorks, Linux, Solaris, and OS/X. As such, this innovation can be used without modification in both flight and ground systems. Integration with DTN enables the CFDP implementation itself to be very simple; therefore, very small. Use of ION infrastructure minimizes consumption of storage and processing resources while maximizing safety.

  11. A performance data network for solar process heat systems

    SciTech Connect

    Barker, G.; Hale, M.J.

    1996-03-01

    A solar process heat (SPH) data network has been developed to access remote-site performance data from operational solar heat systems. Each SPH system in the data network is outfitted with monitoring equipment and a datalogger. The datalogger is accessed via modem from the data network computer at the National Renewable Energy Laboratory (NREL). The dataloggers collect both ten-minute and hourly data and download it to the data network every 24-hours for archiving, processing, and plotting. The system data collected includes energy delivered (fluid temperatures and flow rates) and site meteorological conditions, such as solar insolation and ambient temperature. The SPH performance data network was created for collecting performance data from SPH systems that are serving in industrial applications or from systems using technologies that show promise for industrial applications. The network will be used to identify areas of SPH technology needing further development, to correlate computer models with actual performance, and to improve the credibility of SPH technology. The SPH data network also provides a centralized bank of user-friendly performance data that will give prospective SPH users an indication of how actual systems perform. There are currently three systems being monitored and archived under the SPH data network: two are parabolic trough systems and the third is a flat-plate system. The two trough systems both heat water for prisons; the hot water is used for personal hygiene, kitchen operations, and laundry. The flat plate system heats water for meat processing at a slaughter house. We plan to connect another parabolic trough system to the network during the first months of 1996. We continue to look for good examples of systems using other types of collector technologies and systems serving new applications (such as absorption chilling) to include in the SPH performance data network.

  12. System Identification of X-33 Neural Network

    NASA Technical Reports Server (NTRS)

    Aggarwal, Shiv

    2003-01-01

    present attempt, as a start, focuses only on the entry phase. Since the main engine remains cut off in this phase, there is no thrust acting on the system. This considerably simplifies the equations of motion. We introduce another simplification by assuming the system to be linear after some non-linearities are removed analytically from our consideration. Under these assumptions, the problem could be solved by Classical Statistics by employing the least sum of squares approach. Instead we chose to use the Neural Network method. This method has many advantages. It is modern, more efficient, can be adapted to work even when the assumptions are diluted. In fact, Neural Networks try to model the human brain and are capable of pattern recognition.

  13. A Novel Characterization of Amalgamated Networks in Natural Systems

    PubMed Central

    Barranca, Victor J.; Zhou, Douglas; Cai, David

    2015-01-01

    Densely-connected networks are prominent among natural systems, exhibiting structural characteristics often optimized for biological function. To reveal such features in highly-connected networks, we introduce a new network characterization determined by a decomposition of network-connectivity into low-rank and sparse components. Based on these components, we discover a new class of networks we define as amalgamated networks, which exhibit large functional groups and dense connectivity. Analyzing recent experimental findings on cerebral cortex, food-web, and gene regulatory networks, we establish the unique importance of amalgamated networks in fostering biologically advantageous properties, including rapid communication among nodes, structural stability under attacks, and separation of network activity into distinct functional modules. We further observe that our network characterization is scalable with network size and connectivity, thereby identifying robust features significant to diverse physical systems, which are typically undetectable by conventional characterizations of connectivity. We expect that studying the amalgamation properties of biological networks may offer new insights into understanding their structure-function relationships. PMID:26035066

  14. Network realization of triplet-type quantum stochastic systems

    NASA Astrophysics Data System (ADS)

    Zhou, Shaosheng; Fu, Shizhou; Chen, Yuping

    2017-01-01

    This paper focuses on a problem of network synthesis for a class of quantum stochastic systems. The systems under consideration are of triplet-type form and stem from linear quantum optics and linear quantum circuits. A new quantum network realization approach is proposed by generalizing the scattering operator from the scalar form to a unitary matrix in network components. It shows that the triplet-type quantum stochastic system can be approximated by a quantum network which consists of some one-degree-of-freedom generalized open-quantum harmonic oscillators (1DGQHOs) via series, concatenation and feedback connections.

  15. Predictive Control of Networked Multiagent Systems via Cloud Computing.

    PubMed

    Liu, Guo-Ping

    2017-01-18

    This paper studies the design and analysis of networked multiagent predictive control systems via cloud computing. A cloud predictive control scheme for networked multiagent systems (NMASs) is proposed to achieve consensus and stability simultaneously and to compensate for network delays actively. The design of the cloud predictive controller for NMASs is detailed. The analysis of the cloud predictive control scheme gives the necessary and sufficient conditions of stability and consensus of closed-loop networked multiagent control systems. The proposed scheme is verified to characterize the dynamical behavior and control performance of NMASs through simulations. The outcome provides a foundation for the development of cooperative and coordinative control of NMASs and its applications.

  16. The architecture of a network level intrusion detection system

    SciTech Connect

    Heady, R.; Luger, G.; Maccabe, A.; Servilla, M.

    1990-08-15

    This paper presents the preliminary architecture of a network level intrusion detection system. The proposed system will monitor base level information in network packets (source, destination, packet size, and time), learning the normal patterns and announcing anomalies as they occur. The goal of this research is to determine the applicability of current intrusion detection technology to the detection of network level intrusions. In particular, the authors are investigating the possibility of using this technology to detect and react to worm programs.

  17. Advanced information processing system: Input/output network management software

    NASA Technical Reports Server (NTRS)

    Nagle, Gail; Alger, Linda; Kemp, Alexander

    1988-01-01

    The purpose of this document is to provide the software requirements and specifications for the Input/Output Network Management Services for the Advanced Information Processing System. This introduction and overview section is provided to briefly outline the overall architecture and software requirements of the AIPS system before discussing the details of the design requirements and specifications of the AIPS I/O Network Management software. A brief overview of the AIPS architecture followed by a more detailed description of the network architecture.

  18. H ∞ predictive control of networked control systems

    NASA Astrophysics Data System (ADS)

    Xia, Yuanqing; Li, Li; Liu, Guo-Ping; Shi, Peng

    2011-06-01

    This article is concerned with the problem of H ∞ predictive control of networked control system with random network delay. A new control scheme termed networked predictive control is proposed. This scheme mainly consists of the control prediction generator and network delay compensator. While designing the predictor, the control input to the actuator may be different due to networked induced time-delay and data dropout, and two cases are considered depending on the way that the observer obtains the plant control input u t . The necessary and sufficient conditions are given for the closed-loop networked predictive control system to be stochastically stable for different u t and random network delays in controller to actuator channel (CAC) and sensor to controller channel (SCC). A simulation study shows the effectiveness of the proposed scheme.

  19. The deep space network, volume 18. [Deep Space Instrumentation Facility, Ground Communication Facility, and Network Control System

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The objectives, functions, and organization of the Deep Space Network are summarized. The Deep Space Instrumentation Facility, the Ground Communications Facility, and the Network Control System are described.

  20. Vein matching using artificial neural network in vein authentication systems

    NASA Astrophysics Data System (ADS)

    Noori Hoshyar, Azadeh; Sulaiman, Riza

    2011-10-01

    Personal identification technology as security systems is developing rapidly. Traditional authentication modes like key; password; card are not safe enough because they could be stolen or easily forgotten. Biometric as developed technology has been applied to a wide range of systems. According to different researchers, vein biometric is a good candidate among other biometric traits such as fingerprint, hand geometry, voice, DNA and etc for authentication systems. Vein authentication systems can be designed by different methodologies. All the methodologies consist of matching stage which is too important for final verification of the system. Neural Network is an effective methodology for matching and recognizing individuals in authentication systems. Therefore, this paper explains and implements the Neural Network methodology for finger vein authentication system. Neural Network is trained in Matlab to match the vein features of authentication system. The Network simulation shows the quality of matching as 95% which is a good performance for authentication system matching.

  1. Observing Arctic Ecology using Networked Infomechanical Systems

    NASA Astrophysics Data System (ADS)

    Healey, N. C.; Oberbauer, S. F.; Hollister, R. D.; Tweedie, C. E.; Welker, J. M.; Gould, W. A.

    2012-12-01

    Understanding ecological dynamics is important for investigation into the potential impacts of climate change in the Arctic. Established in the early 1990's, the International Tundra Experiment (ITEX) began observational inquiry of plant phenology, plant growth, community composition, and ecosystem properties as part of a greater effort to study changes across the Arctic. Unfortunately, these observations are labor intensive and time consuming, greatly limiting their frequency and spatial coverage. We have expanded the capability of ITEX to analyze ecological phenomenon with improved spatial and temporal resolution through the use of Networked Infomechanical Systems (NIMS) as part of the Arctic Observing Network (AON) program. The systems exhibit customizable infrastructure that supports a high level of versatility in sensor arrays in combination with information technology that allows for adaptable configurations to numerous environmental observation applications. We observe stereo and static time-lapse photography, air and surface temperature, incoming and outgoing long and short wave radiation, net radiation, and hyperspectral reflectance that provides critical information to understanding how vegetation in the Arctic is responding to ambient climate conditions. These measurements are conducted concurrent with ongoing manual measurements using ITEX protocols. Our NIMS travels at a rate of three centimeters per second while suspended on steel cables that are ~1 m from the surface spanning transects ~50 m in length. The transects are located to span soil moisture gradients across a variety of land cover types including dry heath, moist acidic tussock tundra, shrub tundra, wet meadows, dry meadows, and water tracks. We have deployed NIMS at four locations on the North Slope of Alaska, USA associated with 1 km2 ARCSS vegetation study grids including Barrow, Atqasuk, Toolik Lake, and Imnavait Creek. A fifth system has been deployed in Thule, Greenland beginning in

  2. Decentralised ? - filtering of networked control systems: a jump system approach

    NASA Astrophysics Data System (ADS)

    Al-Radhawi, Muhammad Ali; Bettayeb, Maamar

    2014-10-01

    We consider the problem of decentralised estimation of discrete-time interconnected systems with local estimators communicating with their subsystems over lossy communication channels. Assuming that the packet losses follow the Gilbert-Elliot model, the networked estimation problem can be formulated into a Markovian jump linear system framework. Modelling subsystem interactions as sum quadratic constrained uncertainties, we design mode-dependent decentralised ?-estimators that robustly stabilise the estimator system and guarantee a given disturbance attenuation level. The estimation gains are derived with necessary and sufficient rank-constrained linear matrix inequality conditions. Results are also provided for local mode-dependent estimators. Estimator synthesis is done using a cone-complementarity linearisation algorithm for the rank-constraints. The results are illustrated via an example.

  3. An efficient management system for wireless sensor networks.

    PubMed

    Ma, Yi-Wei; Chen, Jiann-Liang; Huang, Yueh-Min; Lee, Mei-Yu

    2010-01-01

    Wireless sensor networks have garnered considerable attention recently. Networks typically have many sensor nodes, and are used in commercial, medical, scientific, and military applications for sensing and monitoring the physical world. Many researchers have attempted to improve wireless sensor network management efficiency. A Simple Network Management Protocol (SNMP)-based sensor network management system was developed that is a convenient and effective way for managers to monitor and control sensor network operations. This paper proposes a novel WSNManagement system that can show the connections stated of relationships among sensor nodes and can be used for monitoring, collecting, and analyzing information obtained by wireless sensor networks. The proposed network management system uses collected information for system configuration. The function of performance analysis facilitates convenient management of sensors. Experimental results show that the proposed method enhances the alive rate of an overall sensor node system, reduces the packet lost rate by roughly 5%, and reduces delay time by roughly 0.2 seconds. Performance analysis demonstrates that the proposed system is effective for wireless sensor network management.

  4. Identification of Infinite Dimensional Systems via Adaptive Wavelet Neural Networks

    DTIC Science & Technology

    1993-01-01

    We consider identification of distributed systems via adaptive wavelet neural networks (AWNNs). We take advantage of the multiresolution property of...wavelet systems and the computational structure of neural networks to approximate the unknown plant successively. A systematic approach is developed

  5. Bayesian Inference Networks and Spreading Activation in Hypertext Systems.

    ERIC Educational Resources Information Center

    Savoy, Jacques

    1992-01-01

    Describes a method based on Bayesian networks for searching hypertext systems. Discussion covers the use of Bayesian networks for structuring index terms and representing user information needs; use of link semantics based on constrained spreading activation to find starting points for browsing; and evaluation of a prototype system. (64…

  6. Encouraging Autonomy through the Use of a Social Networking System

    ERIC Educational Resources Information Center

    Leis, Adrian

    2014-01-01

    The use of social networking systems has enabled communication to occur around the globe almost instantly, with news about various events being spread around the world as they happen. There has also been much interest in the benefits and disadvantages the use of such social networking systems may bring for education. This paper reports on the use…

  7. Wide Area Network Monitoring System for HEP Experiments at Fermilab

    SciTech Connect

    Grigoriev, M.

    2004-11-23

    Large, distributed High Energy Physics (HEP) collaborations, such as D0, CDF and US-CMS, depend on stable and robust network paths between major world research centres. The evolving emphasis on data and compute Grids increases the reliance on network performance. Fermilab's experimental groups and network support personnel identified a critical need for WAN monitoring to ensure the quality and efficient utilization of such network paths. This has led to the development of the Network Monitoring system we will present in this paper. The system evolved from the IEPM-BW project, started at SLAC three years ago. At Fermilab this system has developed into a fully functional infrastructure with bi-directional active network probes and path characterizations. It is based on the Iperf achievable throughput tool, Ping and Synack to test ICMP/TCP connectivity. It uses Pipechar and Traceroute to test, compare and report hop-by-hop network path characterization. It also measures real file transfer performance by BBFTP and GridFTP. The Monitoring system has an extensive web-interface and all the data is available through standalone SOAP web services or by a MonaLISA client. Also in this paper we will present a case study of network path asymmetry and abnormal performance between FNAL and SDSC, which was discovered and resolved by utilizing the Network Monitoring system.

  8. Wide area network monitoring system for HEP experiments at Fermilab

    SciTech Connect

    Grigoriev, Maxim; Cottrell, Les; Logg, Connie; /SLAC

    2004-12-01

    Large, distributed High Energy Physics (HEP) collaborations, such as D0, CDF and US-CMS, depend on stable and robust network paths between major world research centers. The evolving emphasis on data and compute Grids increases the reliance on network performance. Fermilab's experimental groups and network support personnel identified a critical need for WAN monitoring to ensure the quality and efficient utilization of such network paths. This has led to the development of the Network Monitoring system we will present in this paper. The system evolved from the IEPM-BW project, started at SLAC three years ago. At Fermilab this system has developed into a fully functional infrastructure with bi-directional active network probes and path characterizations. It is based on the Iperf achievable throughput tool, Ping and Synack to test ICMP/TCP connectivity. It uses Pipechar and Traceroute to test, compare and report hop-by-hop network path characterization. It also measures real file transfer performance by BBFTP and GridFTP. The Monitoring system has an extensive web-interface and all the data is available through standalone SOAP web services or by a MonaLISA client. Also in this paper we will present a case study of network path asymmetry and abnormal performance between FNAL and SDSC, which was discovered and resolved by utilizing the Network Monitoring system.

  9. Fusion techniques of fuzzy systems and neural networks, and fuzzy systems and genetic algorithms

    NASA Astrophysics Data System (ADS)

    Takagi, Hideyuki

    1993-12-01

    This paper overviews four combinations of fuzzy logic, neural networks and genetic algorithms: (1) neural networks to auto-design fuzzy systems, (2) employing fuzzy rule structure to construct structured neural networks, (3) genetic algorithms to auto-design fuzzy systems, and (4) a fuzzy knowledge-based system to control genetic parameter dynamically.

  10. Mind wandering and the attention network system.

    PubMed

    Gonçalves, Óscar F; Rêgo, Gabriel; Oliveira-Silva, Patrícia; Leite, Jorge; Carvalho, Sandra; Fregni, Felipe; Amaro, Edson; Boggio, Paulo S

    2017-01-01

    Attention and mind wandering are often seen as anticorrelated. However, both attention and mind wandering are multi-component processes, and their relationship may be more complex than previously thought. In this study, we tested the interference of different types of thoughts as measured by a Thought Identification Task - TIT (on task thoughts, task related interference thoughts, external distractions, stimulus independent and task unrelated thoughts) on different components of the attention network system - ANT (alerting, orienting, executive). Results show that, during the ANT, individuals were predominantly involved in task related interference thoughts which, along with external distractors, significantly impaired their performance accuracy. However, mind wandering (i.e., stimulus independent and task unrelated thoughts) did not significantly interfere with accuracy in the ANT. No significant relationship was found between type of thoughts and alerting, orienting, or executive effects in the ANT. While task related interference thoughts and external distractions seemed to impair performance on the attention task, mind wandering was still compatible with satisfactory performance in the ANT. The present results confirmed the importance of differentiating type of "out of task" thoughts in studying the relationship between though distractors and attention.

  11. A Holistic Approach to Networked Information Systems Design and Analysis

    DTIC Science & Technology

    2016-04-15

    Supply in Systems with Solar Panels and Storage”, Industrial & Systems Engineering Research Conference, Nashville, TN. (Presenter: Gautam), 2015 P4...AFRL-AFOSR-VA-TR-2016-0159 A Holistic Approach to Networked Information Systems Design and Analysis P.R. Kumar TEXAS ENGINEERING EXPERIMENT STATION...necessary if the abstract is to be limited. DISTRIBUTION A: Distribution approved for public release A Holistic Approach to Networked Information Systems

  12. Scalable Hierarchical Network Management System for Displaying Network Information in Three Dimensions

    NASA Technical Reports Server (NTRS)

    George, Jude (Inventor); Schlecht, Leslie (Inventor); McCabe, James D. (Inventor); LeKashman, John Jr. (Inventor)

    1998-01-01

    A network management system has SNMP agents distributed at one or more sites, an input output module at each site, and a server module located at a selected site for communicating with input output modules, each of which is configured for both SNMP and HNMP communications. The server module is configured exclusively for HNMP communications, and it communicates with each input output module according to the HNMP. Non-iconified, informationally complete views are provided of network elements to aid in network management.

  13. Network design sensitivity studies for use of digital cross-connect systems in survivable network architectures

    NASA Astrophysics Data System (ADS)

    Doverspike, Robert D.; Morgan, Jonathan A.; Leland, Will

    1994-01-01

    This paper provides the results of an economic study on the use of SONET Digital Cross-connect Systems (DCS's) to provide survivable transmission network architectures in local exchange networks. Three fundamental survivable transmission technologies are considered: (1) a SONET self-healing ring; (2) a SONET point-to-point fiber system with 1:1 automatic protection switching and diverse routing of protection facilities; and (3) a DCS mesh with automatic DCS restoration (rerouting) protection. These three technologies are used in various combinations to form six survivable network alternatives for evaluation. Two Local Exchange Carrier (LEC) networks are used (a 15 node network and a 53 node network) and demand, network connectivity, and unit equipment cost sensitivities are evaluated on these alternatives. In addition, the survivability of each alternative in the event of major node failure is calculated. The motivation for the study is to determine the viability of DCS-based survivable network architectures and, in particular, the viability of SONET DCS's with integrated optical terminations. The study has two objectives: (1) given a specific survivable network technology, under what conditions is it economical to place a Broadband DCS (B-DCS) in a central office as opposed Add-Drop Multiplexers (ADM's); and (2) which survivable technologies with B-DCS's are economical, and under networks consists of 'hybrids' of SONET point-to-point, ring and mesh technologies, and that the B-DCS is economically viable for interconnection between these technologies.

  14. Adaptive Neural Network Based Control of Noncanonical Nonlinear Systems.

    PubMed

    Zhang, Yanjun; Tao, Gang; Chen, Mou

    2016-09-01

    This paper presents a new study on the adaptive neural network-based control of a class of noncanonical nonlinear systems with large parametric uncertainties. Unlike commonly studied canonical form nonlinear systems whose neural network approximation system models have explicit relative degree structures, which can directly be used to derive parameterized controllers for adaptation, noncanonical form nonlinear systems usually do not have explicit relative degrees, and thus their approximation system models are also in noncanonical forms. It is well-known that the adaptive control of noncanonical form nonlinear systems involves the parameterization of system dynamics. As demonstrated in this paper, it is also the case for noncanonical neural network approximation system models. Effective control of such systems is an open research problem, especially in the presence of uncertain parameters. This paper shows that it is necessary to reparameterize such neural network system models for adaptive control design, and that such reparameterization can be realized using a relative degree formulation, a concept yet to be studied for general neural network system models. This paper then derives the parameterized controllers that guarantee closed-loop stability and asymptotic output tracking for noncanonical form neural network system models. An illustrative example is presented with the simulation results to demonstrate the control design procedure, and to verify the effectiveness of such a new design method.

  15. Network theory and its applications in economic systems

    NASA Astrophysics Data System (ADS)

    Huang, Xuqing

    This dissertation covers the two major parts of my Ph.D. research: i) developing theoretical framework of complex networks; and ii) applying complex networks models to quantitatively analyze economics systems. In part I, we focus on developing theories of interdependent networks, which includes two chapters: 1) We develop a mathematical framework to study the percolation of interdependent networks under targeted-attack and find that when the highly connected nodes are protected and have lower probability to fail, in contrast to single scale-free (SF) networks where the percolation threshold pc = 0, coupled SF networks are significantly more vulnerable with pc significantly larger than zero. 2) We analytically demonstrates that clustering, which quantifies the propensity for two neighbors of the same vertex to also be neighbors of each other, significantly increases the vulnerability of the system. In part II, we apply the complex networks models to study economics systems, which also includes two chapters: 1) We study the US corporate governance network, in which nodes representing directors and links between two directors representing their service on common company boards, and propose a quantitative measure of information and influence transformation in the network. Thus we are able to identify the most influential directors in the network. 2) We propose a bipartite networks model to simulate the risk propagation process among commercial banks during financial crisis. With empirical bank's balance sheet data in 2007 as input to the model, we find that our model efficiently identifies a significant portion of the actual failed banks reported by Federal Deposit Insurance Corporation during the financial crisis between 2008 and 2011. The results suggest that complex networks model could be useful for systemic risk stress testing for financial systems. The model also identifies that commercial rather than residential real estate assets are major culprits for the

  16. Network Management System for Tactical Mobile Ad Hoc Network Segments

    DTIC Science & Technology

    2011-09-01

    Protocol UFO UHF Follow-On UHF Ultra High Frequency USB Universal Serial Bus VHF Very High Frequency VIRT Valuable Information at the Right Time...military satellite system known as the UHF Follow-on system ( UFO ) only provides capacity for 600 concurrent users. DoD users also have commercial

  17. System Identification for Nonlinear Control Using Neural Networks

    NASA Technical Reports Server (NTRS)

    Stengel, Robert F.; Linse, Dennis J.

    1990-01-01

    An approach to incorporating artificial neural networks in nonlinear, adaptive control systems is described. The controller contains three principal elements: a nonlinear inverse dynamic control law whose coefficients depend on a comprehensive model of the plant, a neural network that models system dynamics, and a state estimator whose outputs drive the control law and train the neural network. Attention is focused on the system identification task, which combines an extended Kalman filter with generalized spline function approximation. Continual learning is possible during normal operation, without taking the system off line for specialized training. Nonlinear inverse dynamic control requires smooth derivatives as well as function estimates, imposing stringent goals on the approximating technique.

  18. Communication Software Performance for Linux Clusters with Mesh Connections

    SciTech Connect

    Jie Chen; William Watson

    2003-09-01

    Recent progress in copper based commodity Gigabit Ethernet interconnects enables constructing clusters to achieve extremely high I/O bandwidth at low cost with mesh connections. However, the TCP/IP protocol stack cannot match the improved performance of Gigabit Ethernet networks especially in the case of multiple interconnects on a single host. In this paper, we evaluate and compare the performance characteristics of TCP/IP and M-VIA software that is an implementation of VIA.In particular, we focus on the performance of the software systems for a mesh communication architecture and demonstrate the feasibility of using multiple Gigabit Ethernet cards on one host to achieve aggregated bandwidth and latency that are not only better than what TCP provides but also compare favorably to some of the special purpose high-speed networks. In addition, implementation of a new M-VIA driver for one type of Gigabit Ethernet card will be discussed.

  19. Group Coordination Support in Networked Multimedia Systems

    DTIC Science & Technology

    1999-12-01

    and reaction to turn- taking signals are deemed a high -level social skill rather than a simple stimulus-response mechanism. Turn-yielding and turn...a small group in a high -latency network; (3) a large group in a low-latency network; and ( 4 ) a large group in a high -latency network. We set = 0...the organiza- tion of turn- taking for conversations. Language, 50( 4 ):696{735, 1974. [192] J. H. Saltzer, D. P. Reed, and D. D. Clark. End-to-end

  20. Afloat Networks

    DTIC Science & Technology

    2012-03-01

    down our power grid system, to impact on our governmental system, to impact on our -- on Wall Street, on our financial systems, and to literally...systems, sensors, and increased power . - Unmanned systems in the air and water will employ greater autonomy and be fully integrated with their...Netgear 2% Linksys 2% Panasonic 3% Cisco 5% Alcatel 5% COMPAQ 6% Sun 8% Dell 9% HP 9% Unknown 38% Others 1% Windows XP, 5% Solaris 10, 10% Red Hat Linux

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

    SciTech Connect

    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.

  2. Network Anomaly Detection System with Optimized DS Evidence Theory

    PubMed Central

    Liu, Yuan; Wang, Xiaofeng; Liu, Kaiyu

    2014-01-01

    Network anomaly detection has been focused on by more people with the fast development of computer network. Some researchers utilized fusion method and DS evidence theory to do network anomaly detection but with low performance, and they did not consider features of network—complicated and varied. To achieve high detection rate, we present a novel network anomaly detection system with optimized Dempster-Shafer evidence theory (ODS) and regression basic probability assignment (RBPA) function. In this model, we add weights for each senor to optimize DS evidence theory according to its previous predict accuracy. And RBPA employs sensor's regression ability to address complex network. By four kinds of experiments, we find that our novel network anomaly detection model has a better detection rate, and RBPA as well as ODS optimization methods can improve system performance significantly. PMID:25254258

  3. STIMULUS: End-System Network Interface Controller for 100 Gb/s Wide Area Networks

    SciTech Connect

    Zarkesh-Ha, Payman

    2014-09-12

    The main goal of this research grant is to develop a system-level solution leveraging novel technologies that enable network communications at 100 Gb/s or beyond. University of New Mexico in collaboration with Acadia Optronics LLC has been working on this project to develop the 100 Gb/s Network Interface Controller (NIC) under this Department of Energy (DOE) grant.

  4. An Artificial Neural Network-Based Decision-Support System for Integrated Network Security

    DTIC Science & Technology

    2014-09-01

    AN ARTIFICIAL NEURAL NETWORK-BASED DECISION-SUPPORT SYSTEM FOR INTEGRATED NETWORK SECURITY THESIS ...The views expressed in this thesis are those of the author and do not reflect the official policy or position of the United States Air Force... THESIS Presented to the Faculty Department of Electrical and Computer Engineering Graduate School of Engineering and Management Air Force

  5. Multiple-Valued Immune Network with Apoptosis System

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Takayuki; Tang, Zheng

    In this paper, we describe a new model of immune network based on biological immune response network. We propose an immunity like multiple-valued network with apoptosis mechanism. The model is based on the interaction between B cells and T cells and the biological apoptosis mechanism in human body. With the mechanism, a naturally immune system can be reproduced. The model is also applied to pattern recognition. It gets possible with a conventional model to restricting categories increase of memory patterns.

  6. An Artificial Neural Network Control System for Spacecraft Attitude Stabilization

    DTIC Science & Technology

    1990-06-01

    training is based on the concept of enforced performance. A neural network will learn to meet a specific performance goal if the performance standard...is the only solution to a problem. Performance index training is devised to teach the neural network the time-optimal control law for the system. Real...time adaptation of a neural network in closed loop control of the Crew/Equipment Retriever was demonstrated in computer simulations.

  7. Operation of International Monitoring System Network

    NASA Astrophysics Data System (ADS)

    Nikolova, Svetlana; Araujo, Fernando; Aktas, Kadircan; Malakhova, Marina; Otsuka, Riyo; Han, Dongmei; Assef, Thierry; Nava, Elisabetta; Mickevicius, Sigitas; Agrebi, Abdelouaheb

    2015-04-01

    The IMS is a globally distributed network of monitoring facilities using sensors from four technologies: seismic, hydroacoustic, infrasound and radionuclide. It is designed to detect the seismic and acoustic waves produced by nuclear test explosions and the subsequently released radioactive isotopes. Monitoring stations transmit their data to the IDC in Vienna, Austria, over a global private network known as the GCI. Since 2013, the data availability (DA) requirements for IMS stations account for quality of the data, meaning that in calculation of data availability data should be exclude if: - there is no input from sensor (SHI technology); - the signal consists of constant values (SHI technology); Even more strict are requirements for the DA of the radionuclide (particulate and noble gas) stations - received data have to be analyzed, reviewed and categorized by IDC analysts. In order to satisfy the strict data and network availability requirements of the IMS Network, the operation of the facilities and the GCI are managed by IDC Operations. Operations has following main functions: - to ensure proper operation and functioning of the stations; - to ensure proper operation and functioning of the GCI; - to ensure efficient management of the stations in IDC; - to provide network oversight and incident management. At the core of the IMS Network operations are a series of tools for: monitoring the stations' state of health and data quality, troubleshooting incidents, communicating with internal and external stakeholders, and reporting. The new requirements for data availability increased the importance of the raw data quality monitoring. This task is addressed by development of additional tools for easy and fast identifying problems in data acquisition, regular activities to check compliance of the station parameters with acquired data by scheduled calibration of the seismic network, review of the samples by certified radionuclide laboratories. The DA for the networks of

  8. Communications and control for electric power systems: Power system stability applications of artificial neural networks

    NASA Technical Reports Server (NTRS)

    Toomarian, N.; Kirkham, Harold

    1994-01-01

    This report investigates the application of artificial neural networks to the problem of power system stability. The field of artificial intelligence, expert systems, and neural networks is reviewed. Power system operation is discussed with emphasis on stability considerations. Real-time system control has only recently been considered as applicable to stability, using conventional control methods. The report considers the use of artificial neural networks to improve the stability of the power system. The networks are considered as adjuncts and as replacements for existing controllers. The optimal kind of network to use as an adjunct to a generator exciter is discussed.

  9. Invariant Multiparameter Sensitivity to Characterize Dynamical Systems on Complex Networks

    NASA Astrophysics Data System (ADS)

    Fujiwara, Kenzaburo; Tanaka, Takuma; Nakamura, Kiyohiko

    2015-02-01

    The behavior of systems is determined by the parameters. Because we seldom know the detailed structure of a system, metrics of parameter sensitivity should be independent of how we model the system. We formulate a new parameter sensitivity metric, which we refer to as "invariant multiparameter sensitivity" (IMPS) because it gives the same result for a class of equivalent models of a system. To investigate the property of IMPS, we firstly apply IMPS to resistor circuits and linear dynamical systems. To examine the dependence of IMPS on network structures, we secondly apply IMPS to nonlinear systems on complex networks. We find that the IMPS of networks of phase oscillators is essentially independent of the number of oscillators. We examine the network-structure dependence of IMPS using a simplified solvable model.

  10. Robust Multi-Agent Sensor Network Systems

    DTIC Science & Technology

    2012-05-08

    endeavor to present an asymptotic analysis at first. Due to the space limit, proofs are omitted. A. Theories According to (4), a key property of Tr...consideration at this stage, since various simulations demand different anchor place- ment strategies . 4.2. Upper and lower bound networks We first define...In essence, this partitioning strategy amounts to a divide and conquer method in that the analysis of loca- lization errors in a large-scale network

  11. A lightweight sensor network management system design

    USGS Publications Warehouse

    Yuan, F.; Song, W.-Z.; Peterson, N.; Peng, Y.; Wang, L.; Shirazi, B.; LaHusen, R.

    2008-01-01

    In this paper, we propose a lightweight and transparent management framework for TinyOS sensor networks, called L-SNMS, which minimizes the overhead of management functions, including memory usage overhead, network traffic overhead, and integration overhead. We accomplish this by making L-SNMS virtually transparent to other applications hence requiring minimal integration. The proposed L-SNMS framework has been successfully tested on various sensor node platforms, including TelosB, MICAz and IMote2. ?? 2008 IEEE.

  12. Precise Network Modeling of Systems Genetics Data Using the Bayesian Network Webserver.

    PubMed

    Ziebarth, Jesse D; Cui, Yan

    2017-01-01

    The Bayesian Network Webserver (BNW, http://compbio.uthsc.edu/BNW ) is an integrated platform for Bayesian network modeling of biological datasets. It provides a web-based network modeling environment that seamlessly integrates advanced algorithms for probabilistic causal modeling and reasoning with Bayesian networks. BNW is designed for precise modeling of relatively small networks that contain less than 20 nodes. The structure learning algorithms used by BNW guarantee the discovery of the best (most probable) network structure given the data. To facilitate network modeling across multiple biological levels, BNW provides a very flexible interface that allows users to assign network nodes into different tiers and define the relationships between and within the tiers. This function is particularly useful for modeling systems genetics datasets that often consist of multiscalar heterogeneous genotype-to-phenotype data. BNW enables users to, within seconds or minutes, go from having a simply formatted input file containing a dataset to using a network model to make predictions about the interactions between variables and the potential effects of experimental interventions. In this chapter, we will introduce the functions of BNW and show how to model systems genetics datasets with BNW.

  13. Intrusion Detection System Using Deep Neural Network for In-Vehicle Network Security

    PubMed Central

    Kang, Min-Joo

    2016-01-01

    A novel intrusion detection system (IDS) using a deep neural network (DNN) is proposed to enhance the security of in-vehicular network. The parameters building the DNN structure are trained with probability-based feature vectors that are extracted from the in-vehicular network packets. For a given packet, the DNN provides the probability of each class discriminating normal and attack packets, and, thus the sensor can identify any malicious attack to the vehicle. As compared to the traditional artificial neural network applied to the IDS, the proposed technique adopts recent advances in deep learning studies such as initializing the parameters through the unsupervised pre-training of deep belief networks (DBN), therefore improving the detection accuracy. It is demonstrated with experimental results that the proposed technique can provide a real-time response to the attack with a significantly improved detection ratio in controller area network (CAN) bus. PMID:27271802

  14. Intrusion Detection System Using Deep Neural Network for In-Vehicle Network Security.

    PubMed

    Kang, Min-Joo; Kang, Je-Won

    2016-01-01

    A novel intrusion detection system (IDS) using a deep neural network (DNN) is proposed to enhance the security of in-vehicular network. The parameters building the DNN structure are trained with probability-based feature vectors that are extracted from the in-vehicular network packets. For a given packet, the DNN provides the probability of each class discriminating normal and attack packets, and, thus the sensor can identify any malicious attack to the vehicle. As compared to the traditional artificial neural network applied to the IDS, the proposed technique adopts recent advances in deep learning studies such as initializing the parameters through the unsupervised pre-training of deep belief networks (DBN), therefore improving the detection accuracy. It is demonstrated with experimental results that the proposed technique can provide a real-time response to the attack with a significantly improved detection ratio in controller area network (CAN) bus.

  15. Designing A Robust Command, Communications and Data Acquisition System For Autonomous Sensor Platforms Using The Data Transport Network

    NASA Astrophysics Data System (ADS)

    Valentic, T. A.

    2012-12-01

    The Data Transport Network is designed for the delivery of data from scientific instruments located at remote field sites with limited or unreliable communications. Originally deployed at the Sondrestrom Research Facility in Greenland over a decade ago, the system supports the real-time collection and processing of data from large instruments such as incoherent scatter radars and lidars. In recent years, the Data Transport Network has been adapted to small, low-power embedded systems controlling remote instrumentation platforms deployed throughout the Arctic. These projects include multiple buoys from the O-Buoy, IceLander and IceGoat programs, renewable energy monitoring at the Imnavait Creek and Ivotuk field sites in Alaska and remote weather observation stations in Alaska and Greenland. This presentation will discuss the common communications controller developed for these projects. Although varied in their application, each of these systems share a number of common features. Multiple instruments are attached, each of which needs to be power controlled, data sampled and files transmitted offsite. In addition, the power usage of the overall system must be minimized to handle the limited energy available from sources such as solar, wind and fuel cells. The communications links are satellite based. The buoys and weather stations utilize Iridium, necessitating the need to handle the common drop outs and high-latency, low-bandwidth nature of the link. The communications controller is an off-the-shelf, low-power, single board computer running a customized version of the Linux operating system. The Data Transport Network provides a Python-based software framework for writing individual data collection programs and supplies a number of common services for configuration, scheduling, logging, data transmission and resource management. Adding a new instrument involves writing only the necessary code for interfacing to the hardware. Individual programs communicate with the

  16. Verification and Validation of Neural Networks for Aerospace Systems

    NASA Technical Reports Server (NTRS)

    Mackall, Dale; Nelson, Stacy; Schumann, Johann

    2002-01-01

    The Dryden Flight Research Center V&V working group and NASA Ames Research Center Automated Software Engineering (ASE) group collaborated to prepare this report. The purpose is to describe V&V processes and methods for certification of neural networks for aerospace applications, particularly adaptive flight control systems like Intelligent Flight Control Systems (IFCS) that use neural networks. This report is divided into the following two sections: Overview of Adaptive Systems and V&V Processes/Methods.

  17. Verification and Validation of Neural Networks for Aerospace Systems

    NASA Technical Reports Server (NTRS)

    Mackall, Dale; Nelson, Stacy; Schumman, Johann; Clancy, Daniel (Technical Monitor)

    2002-01-01

    The Dryden Flight Research Center V&V working group and NASA Ames Research Center Automated Software Engineering (ASE) group collaborated to prepare this report. The purpose is to describe V&V processes and methods for certification of neural networks for aerospace applications, particularly adaptive flight control systems like Intelligent Flight Control Systems (IFCS) that use neural networks. This report is divided into the following two sections: 1) Overview of Adaptive Systems; and 2) V&V Processes/Methods.

  18. Dynamic structural network evolution in compressed granular systems

    NASA Astrophysics Data System (ADS)

    Papadopoulos, Lia; Puckett, James; Daniels, Karen; Bassett, Danielle

    The heterogeneous dynamic behavior of granular packings under shear or compression is not well-understood. In this study, we use novel techniques from network science to investigate the structural evolution that occurs in compressed granular systems. Specifically, we treat particles as network nodes, and pressure-dependent forces between particles as layer-specific network edges. Then, we use a generalization of community detection methods to multilayer networks, and develop quantitative measures that characterize changes in the architecture of the force network as a function of pressure. We observe that branchlike domains reminiscent of force chains evolve differentially as pressure is applied: topological characteristics of these domains at rest predict their coalescence or dispersion under pressure. Our methods allow us to study the dynamics of mesoscale structure in granular systems, and provide a direct way to compare data from systems under different external conditions or with different physical makeup.

  19. The middleware architecture supports heterogeneous network systems for module-based personal robot system

    NASA Astrophysics Data System (ADS)

    Choo, Seongho; Li, Vitaly; Choi, Dong Hee; Jung, Gi Deck; Park, Hong Seong; Ryuh, Youngsun

    2005-12-01

    On developing the personal robot system presently, the internal architecture is every module those occupy separated functions are connected through heterogeneous network system. This module-based architecture supports specialization and division of labor at not only designing but also implementation, as an effect of this architecture, it can reduce developing times and costs for modules. Furthermore, because every module is connected among other modules through network systems, we can get easy integrations and synergy effect to apply advanced mutual functions by co-working some modules. In this architecture, one of the most important technologies is the network middleware that takes charge communications among each modules connected through heterogeneous networks systems. The network middleware acts as the human nerve system inside of personal robot system; it relays, transmits, and translates information appropriately between modules that are similar to human organizations. The network middleware supports various hardware platform, heterogeneous network systems (Ethernet, Wireless LAN, USB, IEEE 1394, CAN, CDMA-SMS, RS-232C). This paper discussed some mechanisms about our network middleware to intercommunication and routing among modules, methods for real-time data communication and fault-tolerant network service. There have designed and implemented a layered network middleware scheme, distributed routing management, network monitoring/notification technology on heterogeneous networks for these goals. The main theme is how to make routing information in our network middleware. Additionally, with this routing information table, we appended some features. Now we are designing, making a new version network middleware (we call 'OO M/W') that can support object-oriented operation, also are updating program sources itself for object-oriented architecture. It is lighter, faster, and can support more operation systems and heterogeneous network systems, but other general

  20. Nonlinear system identification and control based on modular neural networks.

    PubMed

    Puscasu, Gheorghe; Codres, Bogdan

    2011-08-01

    A new approach for nonlinear system identification and control based on modular neural networks (MNN) is proposed in this paper. The computational complexity of neural identification can be greatly reduced if the whole system is decomposed into several subsystems. This is obtained using a partitioning algorithm. Each local nonlinear model is associated with a nonlinear controller. These are also implemented by neural networks. The switching between the neural controllers is done by a dynamical switcher, also implemented by neural networks, that tracks the different operating points. The proposed multiple modelling and control strategy has been successfully tested on simulated laboratory scale liquid-level system.

  1. Data and Network Science for Noisy Heterogeneous Systems

    ERIC Educational Resources Information Center

    Rider, Andrew Kent

    2013-01-01

    Data in many growing fields has an underlying network structure that can be taken advantage of. In this dissertation we apply data and network science to problems in the domains of systems biology and healthcare. Data challenges in these fields include noisy, heterogeneous data, and a lack of ground truth. The primary thesis of this work is that…

  2. A Systems Theory View of Organizations as Communication Networks.

    ERIC Educational Resources Information Center

    Schwartz, Donald F.

    Focusing on the analysis of communication networks within organizations with an eye toward implications for study of external communication, this paper (1) develops a systems theory/communication view of the nature of formal organizations, (2) illustrates the notion of holistic organizational communication networks in organizations which include…

  3. Applying Model Based Systems Engineering to NASA's Space Communications Networks

    NASA Technical Reports Server (NTRS)

    Bhasin, Kul; Barnes, Patrick; Reinert, Jessica; Golden, Bert

    2013-01-01

    System engineering practices for complex systems and networks now require that requirement, architecture, and concept of operations product development teams, simultaneously harmonize their activities to provide timely, useful and cost-effective products. When dealing with complex systems of systems, traditional systems engineering methodology quickly falls short of achieving project objectives. This approach is encumbered by the use of a number of disparate hardware and software tools, spreadsheets and documents to grasp the concept of the network design and operation. In case of NASA's space communication networks, since the networks are geographically distributed, and so are its subject matter experts, the team is challenged to create a common language and tools to produce its products. Using Model Based Systems Engineering methods and tools allows for a unified representation of the system in a model that enables a highly related level of detail. To date, Program System Engineering (PSE) team has been able to model each network from their top-level operational activities and system functions down to the atomic level through relational modeling decomposition. These models allow for a better understanding of the relationships between NASA's stakeholders, internal organizations, and impacts to all related entities due to integration and sustainment of existing systems. Understanding the existing systems is essential to accurate and detailed study of integration options being considered. In this paper, we identify the challenges the PSE team faced in its quest to unify complex legacy space communications networks and their operational processes. We describe the initial approaches undertaken and the evolution toward model based system engineering applied to produce Space Communication and Navigation (SCaN) PSE products. We will demonstrate the practice of Model Based System Engineering applied to integrating space communication networks and the summary of its

  4. Systems Approaches to Identifying Gene Regulatory Networks in Plants

    PubMed Central

    Long, Terri A.; Brady, Siobhan M.; Benfey, Philip N.

    2009-01-01

    Complex gene regulatory networks are composed of genes, noncoding RNAs, proteins, metabolites, and signaling components. The availability of genome-wide mutagenesis libraries; large-scale transcriptome, proteome, and metabalome data sets; and new high-throughput methods that uncover protein interactions underscores the need for mathematical modeling techniques that better enable scientists to synthesize these large amounts of information and to understand the properties of these biological systems. Systems biology approaches can allow researchers to move beyond a reductionist approach and to both integrate and comprehend the interactions of multiple components within these systems. Descriptive and mathematical models for gene regulatory networks can reveal emergent properties of these plant systems. This review highlights methods that researchers are using to obtain large-scale data sets, and examples of gene regulatory networks modeled with these data. Emergent properties revealed by the use of these network models and perspectives on the future of systems biology are discussed. PMID:18616425

  5. On neural networks in identification and control of dynamic systems

    NASA Technical Reports Server (NTRS)

    Phan, Minh; Juang, Jer-Nan; Hyland, David C.

    1993-01-01

    This paper presents a discussion of the applicability of neural networks in the identification and control of dynamic systems. Emphasis is placed on the understanding of how the neural networks handle linear systems and how the new approach is related to conventional system identification and control methods. Extensions of the approach to nonlinear systems are then made. The paper explains the fundamental concepts of neural networks in their simplest terms. Among the topics discussed are feed forward and recurrent networks in relation to the standard state-space and observer models, linear and nonlinear auto-regressive models, linear, predictors, one-step ahead control, and model reference adaptive control for linear and nonlinear systems. Numerical examples are presented to illustrate the application of these important concepts.

  6. Network component analysis: reconstruction of regulatory signals in biological systems.

    PubMed

    Liao, James C; Boscolo, Riccardo; Yang, Young-Lyeol; Tran, Linh My; Sabatti, Chiara; Roychowdhury, Vwani P

    2003-12-23

    High-dimensional data sets generated by high-throughput technologies, such as DNA microarray, are often the outputs of complex networked systems driven by hidden regulatory signals. Traditional statistical methods for computing low-dimensional or hidden representations of these data sets, such as principal component analysis and independent component analysis, ignore the underlying network structures and provide decompositions based purely on a priori statistical constraints on the computed component signals. The resulting decomposition thus provides a phenomenological model for the observed data and does not necessarily contain physically or biologically meaningful signals. Here, we develop a method, called network component analysis, for uncovering hidden regulatory signals from outputs of networked systems, when only a partial knowledge of the underlying network topology is available. The a priori network structure information is first tested for compliance with a set of identifiability criteria. For networks that satisfy the criteria, the signals from the regulatory nodes and their strengths of influence on each output node can be faithfully reconstructed. This method is first validated experimentally by using the absorbance spectra of a network of various hemoglobin species. The method is then applied to microarray data generated from yeast Saccharamyces cerevisiae and the activities of various transcription factors during cell cycle are reconstructed by using recently discovered connectivity information for the underlying transcriptional regulatory networks.

  7. Networks to Strengthen Health Systems for Chronic Disease Prevention

    PubMed Central

    Riley, Barbara L.; Herbert, Carol P.; Best, Allan

    2013-01-01

    Interorganizational networks that harness the priorities, capacities, and skills of various agencies and individuals have emerged as useful approaches for strengthening preventive services in public health systems. We use examples from the Canadian Heart Health Initiative and Alberta’s Primary Care Networks to illustrate characteristics of networks, describe the limitations of existing frameworks for assessing the performance of prevention-oriented networks, and propose a research agenda for guiding future efforts to improve the performance of these initiatives. Prevention-specific assessment strategies that capture relevant aspects of network performance need to be identified, and feedback mechanisms are needed that make better use of these data to drive change in network activities. PMID:24028225

  8. Decision support systems and methods for complex networks

    DOEpatents

    Huang, Zhenyu [Richland, WA; Wong, Pak Chung [Richland, WA; Ma, Jian [Richland, WA; Mackey, Patrick S [Richland, WA; Chen, Yousu [Richland, WA; Schneider, Kevin P [Seattle, WA

    2012-02-28

    Methods and systems for automated decision support in analyzing operation data from a complex network. Embodiments of the present invention utilize these algorithms and techniques not only to characterize the past and present condition of a complex network, but also to predict future conditions to help operators anticipate deteriorating and/or problem situations. In particular, embodiments of the present invention characterize network conditions from operation data using a state estimator. Contingency scenarios can then be generated based on those network conditions. For at least a portion of all of the contingency scenarios, risk indices are determined that describe the potential impact of each of those scenarios. Contingency scenarios with risk indices are presented visually as graphical representations in the context of a visual representation of the complex network. Analysis of the historical risk indices based on the graphical representations can then provide trends that allow for prediction of future network conditions.

  9. [Study for lung sound acquisition module based on ARM and Linux].

    PubMed

    Lu, Qiang; Li, Wenfeng; Zhang, Xixue; Li, Junmin; Liu, Longqing

    2011-07-01

    A acquisition module with ARM and Linux as a core was developed. This paper presents the hardware configuration and the software design. It is shown that the module can extract human lung sound reliably and effectively.

  10. LDCM Ground System. Network Lesson Learned

    NASA Technical Reports Server (NTRS)

    Gal-Edd, Jonathan

    2010-01-01

    This slide presentation reviews the Landsat Data Continuity Mission (LDCM) and the lessons learned in implementing the network that was assembled to allow for the acquisition, archiving and distribution of the data from the Landsat mission. The objective of the LDCM is to continue the acquisition, archiving, and distribution of moderate-resolution multispectral imagery affording global, synoptic, and repetitive coverage of the earth's land surface at a scale where natural and human-induced changes can be detected, differentiated, characterized, and monitored over time. It includes a review of the ground network, including a block diagram of the ground network elements (GNE) and a review of the RF design and testing. Also included is a listing of the lessons learned.

  11. A Mobile Sensor Network System for Monitoring of Unfriendly Environments

    PubMed Central

    Song, Guangming; Zhou, Yaoxin; Ding, Fei; Song, Aiguo

    2008-01-01

    Observing microclimate changes is one of the most popular applications of wireless sensor networks. However, some target environments are often too dangerous or inaccessible to humans or large robots and there are many challenges for deploying and maintaining wireless sensor networks in those unfriendly environments. This paper presents a mobile sensor network system for solving this problem. The system architecture, the mobile node design, the basic behaviors and advanced network capabilities have been investigated respectively. A wheel-based robotic node architecture is proposed here that can add controlled mobility to wireless sensor networks. A testbed including some prototype nodes has also been created for validating the basic functions of the proposed mobile sensor network system. Motion performance tests have been done to get the positioning errors and power consumption model of the mobile nodes. Results of the autonomous deployment experiment show that the mobile nodes can be distributed evenly into the previously unknown environments. It provides powerful support for network deployment and maintenance and can ensure that the sensor network will work properly in unfriendly environments. PMID:27873927

  12. A Mobile Sensor Network System for Monitoring of Unfriendly Environments.

    PubMed

    Song, Guangming; Zhou, Yaoxin; Ding, Fei; Song, Aiguo

    2008-11-14

    Observing microclimate changes is one of the most popular applications of wireless sensor networks. However, some target environments are often too dangerous or inaccessible to humans or large robots and there are many challenges for deploying and maintaining wireless sensor networks in those unfriendly environments. This paper presents a mobile sensor network system for solving this problem. The system architecture, the mobile node design, the basic behaviors and advanced network capabilities have been investigated respectively. A wheel-based robotic node architecture is proposed here that can add controlled mobility to wireless sensor networks. A testbed including some prototype nodes has also been created for validating the basic functions of the proposed mobile sensor network system. Motion performance tests have been done to get the positioning errors and power consumption model of the mobile nodes. Results of the autonomous deployment experiment show that the mobile nodes can be distributed evenly into the previously unknown environments. It provides powerful support for network deployment and maintenance and can ensure that the sensor network will work properly in unfriendly environments.

  13. A complex network-based importance measure for mechatronics systems

    NASA Astrophysics Data System (ADS)

    Wang, Yanhui; Bi, Lifeng; Lin, Shuai; Li, Man; Shi, Hao

    2017-01-01

    In view of the negative impact of functional dependency, this paper attempts to provide an alternative importance measure called Improved-PageRank (IPR) for measuring the importance of components in mechatronics systems. IPR is a meaningful extension of the centrality measures in complex network, which considers usage reliability of components and functional dependency between components to increase importance measures usefulness. Our work makes two important contributions. First, this paper integrates the literature of mechatronic architecture and complex networks theory to define component network. Second, based on the notion of component network, a meaningful IPR is brought into the identifying of important components. In addition, the IPR component importance measures, and an algorithm to perform stochastic ordering of components due to the time-varying nature of usage reliability of components and functional dependency between components, are illustrated with a component network of bogie system that consists of 27 components.

  14. NSTX-U Advances in Real-Time C++11 on Linux

    SciTech Connect

    Erickson, Keith G.

    2015-08-14

    Programming languages like C and Ada combined with proprietary embedded operating systems have dominated the real-time application space for decades. The new C++11standard includes native, language-level support for concurrency, a required feature for any nontrivial event-oriented real-time software. Threads, Locks, and Atomics now exist to provide the necessary tools to build the structures that make up the foundation of a complex real-time system. The National Spherical Torus Experiment Upgrade (NSTX-U) at the Princeton Plasma Physics Laboratory (PPPL) is breaking new ground with the language as applied to the needs of fusion devices. A new Digital Coil Protection System (DCPS) will serve as the main protection mechanism for the magnetic coils, and it is written entirely in C++11 running on Concurrent Computer Corporation's real-time operating system, RedHawk Linux. It runs over 600 algorithms in a 5 kHz control loop that determine whether or not to shut down operations before physical damage occurs. To accomplish this, NSTX-U engineers developed software tools that do not currently exist elsewhere, including real-time atomic synchronization, real-time containers, and a real-time logging framework. Together with a recent (and carefully configured) version of the GCC compiler, these tools enable data acquisition, processing, and output using a conventional operating system to meet a hard real-time deadline (that is, missing one periodic is a failure) of 200 microseconds.

  15. NSTX-U Advances in Real-Time C++11 on Linux

    DOE PAGES

    Erickson, Keith G.

    2015-08-14

    Programming languages like C and Ada combined with proprietary embedded operating systems have dominated the real-time application space for decades. The new C++11standard includes native, language-level support for concurrency, a required feature for any nontrivial event-oriented real-time software. Threads, Locks, and Atomics now exist to provide the necessary tools to build the structures that make up the foundation of a complex real-time system. The National Spherical Torus Experiment Upgrade (NSTX-U) at the Princeton Plasma Physics Laboratory (PPPL) is breaking new ground with the language as applied to the needs of fusion devices. A new Digital Coil Protection System (DCPS) willmore » serve as the main protection mechanism for the magnetic coils, and it is written entirely in C++11 running on Concurrent Computer Corporation's real-time operating system, RedHawk Linux. It runs over 600 algorithms in a 5 kHz control loop that determine whether or not to shut down operations before physical damage occurs. To accomplish this, NSTX-U engineers developed software tools that do not currently exist elsewhere, including real-time atomic synchronization, real-time containers, and a real-time logging framework. Together with a recent (and carefully configured) version of the GCC compiler, these tools enable data acquisition, processing, and output using a conventional operating system to meet a hard real-time deadline (that is, missing one periodic is a failure) of 200 microseconds.« less

  16. Interconnecting PV on New York City's Secondary Network Distribution System

    SciTech Connect

    Anderson, K; Coddington, M; Burman, K; Hayter, S; Kroposki, B; Watson, and A

    2009-11-01

    The U.S. Department of Energy (DOE) has teamed with cities across the country through the Solar America Cities (SAC) partnership program to help reduce barriers and accelerate implementation of solar energy. The New York City SAC team is a partnership between the City University of New York (CUNY), the New York City Mayor s Office of Long-term Planning and Sustainability, and the New York City Economic Development Corporation (NYCEDC).The New York City SAC team is working with DOE s National Renewable Energy Laboratory (NREL) and Con Edison, the local utility, to develop a roadmap for photovoltaic (PV) installations in the five boroughs. The city set a goal to increase its installed PV capacity from1.1 MW in 2005 to 8.1 MW by 2015 (the maximum allowed in 2005). A key barrier to reaching this goal, however, is the complexity of the interconnection process with the local utility. Unique challenges are associated with connecting distributed PV systems to secondary network distribution systems (simplified to networks in this report). Although most areas of the country use simpler radial distribution systems to distribute electricity, larger metropolitan areas like New York City typically use networks to increase reliability in large load centers. Unlike the radial distribution system, where each customer receives power through a single line, a network uses a grid of interconnected lines to deliver power to each customer through several parallel circuits and sources. This redundancy improves reliability, but it also requires more complicated coordination and protection schemes that can be disrupted by energy exported from distributed PV systems. Currently, Con Edison studies each potential PV system in New York City to evaluate the system s impact on the network, but this is time consuming for utility engineers and may delay the customer s project or add cost for larger installations. City leaders would like to streamline this process to facilitate faster, simpler, and

  17. Optical production systems using neural networks and symbolic substitution

    NASA Technical Reports Server (NTRS)

    Botha, Elizabeth; Casasent, David; Barnard, Etienne

    1988-01-01

    Two optical implementations of production systems are advanced. The production systems operate on a knowledge base where facts and rules are encoded as formulas in propositional calculus. The first implementation is a binary neural network. An analog neural network is used to include reasoning with uncertainties. The second implementation uses a new optical symbolic substitution correlator. This implementation is useful when a set of similar situations has to be handled in parallel on one processor.

  18. Systems and methods for modeling and analyzing networks

    DOEpatents

    Hill, Colin C; Church, Bruce W; McDonagh, Paul D; Khalil, Iya G; Neyarapally, Thomas A; Pitluk, Zachary W

    2013-10-29

    The systems and methods described herein utilize a probabilistic modeling framework for reverse engineering an ensemble of causal models, from data and then forward simulating the ensemble of models to analyze and predict the behavior of the network. In certain embodiments, the systems and methods described herein include data-driven techniques for developing causal models for biological networks. Causal network models include computational representations of the causal relationships between independent variables such as a compound of interest and dependent variables such as measured DNA alterations, changes in mRNA, protein, and metabolites to phenotypic readouts of efficacy and toxicity.

  19. NETWORKS, BIOLOGY AND SYSTEMS ENGINEERING: A CASE STUDY IN INFLAMMATION

    PubMed Central

    Foteinou, P.T.; Yang, E.; Androulakis, I. P.

    2009-01-01

    Biological systems can be modeled as networks of interacting components across multiple scales. A central problem in computational systems biology is to identify those critical components and the rules that define their interactions and give rise to the emergent behavior of a host response. In this paper we will discuss two fundamental problems related to the construction of transcription factor networks and the identification of networks of functional modules describing disease progression. We focus on inflammation as a key physiological response of clinical and translational importance. PMID:20161495

  20. A local area computer network expert system framework

    NASA Technical Reports Server (NTRS)

    Dominy, Robert

    1987-01-01

    Over the past years an expert system called LANES designed to detect and isolate faults in the Goddard-wide Hybrid Local Area Computer Network (LACN) was developed. As a result, the need for developing a more generic LACN fault isolation expert system has become apparent. An object oriented approach was explored to create a set of generic classes, objects, rules, and methods that would be necessary to meet this need. The object classes provide a convenient mechanism for separating high level information from low level network specific information. This approach yeilds a framework which can be applied to different network configurations and be easily expanded to meet new needs.

  1. Neural networks and logical reasoning systems: a translation table.

    PubMed

    Martins, J; Mendes, R V

    2001-04-01

    A correspondence is established between the basic elements of logic reasoning systems (knowledge bases, rules, inference and queries) and the structure and dynamical evolution laws of neural networks. The correspondence is pictured as a translation dictionary which might allow to go back and forth between symbolic and network formulations, a desirable step in learning-oriented systems and multicomputer networks. In the framework of Horn clause logics, it is found that atomic propositions with n arguments correspond to nodes with nth order synapses, rules to synaptic intensity constraints, forward chaining to synaptic dynamics and queries either to simple node activation or to a query tensor dynamics.

  2. Multi-terabyte EIDE disk arrays running Linux RAID5

    SciTech Connect

    Sanders, D.A.; Cremaldi, L.M.; Eschenburg, V.; Godang, R.; Joy, M.D.; Summers, D.J.; Petravick, D.L.; /Fermilab

    2004-11-01

    High-energy physics experiments are currently recording large amounts of data and in a few years will be recording prodigious quantities of data. New methods must be developed to handle this data and make analysis at universities possible. Grid Computing is one method; however, the data must be cached at the various Grid nodes. We examine some storage techniques that exploit recent developments in commodity hardware. Disk arrays using RAID level 5 (RAID-5) include both parity and striping. The striping improves access speed. The parity protects data in the event of a single disk failure, but not in the case of multiple disk failures. We report on tests of dual-processor Linux Software RAID-5 arrays and Hardware RAID-5 arrays using a 12-disk 3ware controller, in conjunction with 250 and 300 GB disks, for use in offline high-energy physics data analysis. The price of IDE disks is now less than $1/GB. These RAID-5 disk arrays can be scaled to sizes affordable to small institutions and used when fast random access at low cost is important.

  3. Cellular computational networks--a scalable architecture for learning the dynamics of large networked systems.

    PubMed

    Luitel, Bipul; Venayagamoorthy, Ganesh Kumar

    2014-02-01

    Neural networks for implementing large networked systems such as smart electric power grids consist of multiple inputs and outputs. Many outputs lead to a greater number of parameters to be adapted. Each additional variable increases the dimensionality of the problem and hence learning becomes a challenge. Cellular computational networks (CCNs) are a class of sparsely connected dynamic recurrent networks (DRNs). By proper selection of a set of input elements for each output variable in a given application, a DRN can be modified into a CCN which significantly reduces the complexity of the neural network and allows use of simple training methods for independent learning in each cell thus making it scalable. This article demonstrates this concept of developing a CCN using dimensionality reduction in a DRN for scalability and better performance. The concept has been analytically explained and empirically verified through application.

  4. Social Insects: A Model System for Network Dynamics

    NASA Astrophysics Data System (ADS)

    Charbonneau, Daniel; Blonder, Benjamin; Dornhaus, Anna

    Social insect colonies (ants, bees, wasps, and termites) show sophisticated collective problem-solving in the face of variable constraints. Individuals exchange information and materials such as food. The resulting network structure and dynamics can inform us about the mechanisms by which the insects achieve particular collective behaviors and these can be transposed to man-made and social networks. We discuss how network analysis can answer important questions about social insects, such as how effective task allocation or information flow is realized. We put forward the idea that network analysis methods are under-utilized in social insect research, and that they can provide novel ways to view the complexity of collective behavior, particularly if network dynamics are taken into account. To illustrate this, we present an example of network tasks performed by ant workers, linked by instances of workers switching from one task to another. We show how temporal network analysis can propose and test new hypotheses on mechanisms of task allocation, and how adding temporal elements to static networks can drastically change results. We discuss the benefits of using social insects as models for complex systems in general. There are multiple opportunities emergent technologies and analysis methods in facilitating research on social insect network. The potential for interdisciplinary work could significantly advance diverse fields such as behavioral ecology, computer sciences, and engineering.

  5. Audit Trail Management System in Community Health Care Information Network.

    PubMed

    Nakamura, Naoki; Nakayama, Masaharu; Nakaya, Jun; Tominaga, Teiji; Suganuma, Takuo; Shiratori, Norio

    2015-01-01

    After the Great East Japan Earthquake we constructed a community health care information network system. Focusing on the authentication server and portal server capable of SAML&ID-WSF, we proposed an audit trail management system to look over audit events in a comprehensive manner. Through implementation and experimentation, we verified the effectiveness of our proposed audit trail management system.

  6. Implementation of an Adaptive Learning System Using a Bayesian Network

    ERIC Educational Resources Information Center

    Yasuda, Keiji; Kawashima, Hiroyuki; Hata, Yoko; Kimura, Hiroaki

    2015-01-01

    An adaptive learning system is proposed that incorporates a Bayesian network to efficiently gauge learners' understanding at the course-unit level. Also, learners receive content that is adapted to their measured level of understanding. The system works on an iPad via the Edmodo platform. A field experiment using the system in an elementary school…

  7. A Gamma Memory Neural Network for System Identification

    NASA Technical Reports Server (NTRS)

    Motter, Mark A.; Principe, Jose C.

    1992-01-01

    A gamma neural network topology is investigated for a system identification application. A discrete gamma memory structure is used in the input layer, providing delayed values of both the control inputs and the network output to the input layer. The discrete gamma memory structure implements a tapped dispersive delay line, with the amount of dispersion regulated by a single, adaptable parameter. The network is trained using static back propagation, but captures significant features of the system dynamics. The system dynamics identified with the network are the Mach number dynamics of the 16 Foot Transonic Tunnel at NASA Langley Research Center, Hampton, Virginia. The training data spans an operating range of Mach numbers from 0.4 to 1.3.

  8. Optimal water quality monitoring network design for river systems.

    PubMed

    Telci, Ilker T; Nam, Kijin; Guan, Jiabao; Aral, Mustafa M

    2009-07-01

    Typical tasks of a river monitoring network design include the selection of the water quality parameters, selection of sampling and measurement methods for these parameters, identification of the locations of sampling stations and determination of the sampling frequencies. These primary design considerations may require a variety of objectives, constraints and solutions. In this study we focus on the optimal river water quality monitoring network design aspect of the overall monitoring program and propose a novel methodology for the analysis of this problem. In the proposed analysis, the locations of sampling sites are determined such that the contaminant detection time is minimized for the river network while achieving maximum reliability for the monitoring system performance. Altamaha river system in the State of Georgia, USA is chosen as an example to demonstrate the proposed methodology. The results show that the proposed model can be effectively used for the optimal design of monitoring networks in river systems.

  9. System for testing properties of a network

    SciTech Connect

    Rawle, Michael; Bartholomew, David B.; Soares, Marshall A.

    2009-06-16

    A method for identifying properties of a downhole electromagnetic network in a downhole tool sting, including the step of providing an electromagnetic path intermediate a first location and a second location on the electromagnetic network. The method further includes the step of providing a receiver at the second location. The receiver includes a known reference. The analog signal includes a set amplitude, a set range of frequencies, and a set rate of change between the frequencies. The method further includes the steps of sending the analog signal, and passively modifying the signal. The analog signal is sent from the first location through the electromagnetic path, and the signal is modified by the properties of the electromagnetic path. The method further includes the step of receiving a modified signal at the second location and comparing the known reference to the modified signal.

  10. The Casualty Network System Capstone Project

    DTIC Science & Technology

    2012-12-01

    Department of Defense ECG – Electrocardiogram EM – Evacuation Module EMS – Emergency Medical Services FST – Forward Surgical Team HADR – Humanitarian...theatre of operations, little information is available about a patient prior to receiving them at the MEDEVAC and FST /CSH. This lack of medical...satellite connection is established with the AF network, outside sources may connect. These sources include the FST , CSH, and rear-echelon Military

  11. Unknown input observer design and analysis for networked control systems

    NASA Astrophysics Data System (ADS)

    Taha, Ahmad F.; Elmahdi, Ahmed; Panchal, Jitesh H.; Sun, Dengfeng

    2015-05-01

    The insertion of communication networks in the feedback loops of control systems is a defining feature of modern control systems. These systems are often subject to unknown inputs in a form of disturbances, perturbations, or attacks. The objective of this paper is to design and analyse an observer for networked dynamical systems with unknown inputs. The network effect can be viewed as either a perturbation or time-delay to the exchanged signals. In this paper, we (1) review an unknown input observer (UIO) design for a non-networked system, (2) derive the networked unknown input observer (NetUIO) dynamics, (3) design a NetUIO such that the effect of higher delay order terms are nullified and (4) establish stability-guaranteeing bounds on the networked-induced time-delay and perturbation. The formulation and results derived in this paper can be generalised to scenarios and applications where the signals are perturbed due to a different source of perturbation or delay.

  12. Optical interconnection networks for high-performance computing systems.

    PubMed

    Biberman, Aleksandr; Bergman, Keren

    2012-04-01

    Enabled by silicon photonic technology, optical interconnection networks have the potential to be a key disruptive technology in computing and communication industries. The enduring pursuit of performance gains in computing, combined with stringent power constraints, has fostered the ever-growing computational parallelism associated with chip multiprocessors, memory systems, high-performance computing systems and data centers. Sustaining these parallelism growths introduces unique challenges for on- and off-chip communications, shifting the focus toward novel and fundamentally different communication approaches. Chip-scale photonic interconnection networks, enabled by high-performance silicon photonic devices, offer unprecedented bandwidth scalability with reduced power consumption. We demonstrate that the silicon photonic platforms have already produced all the high-performance photonic devices required to realize these types of networks. Through extensive empirical characterization in much of our work, we demonstrate such feasibility of waveguides, modulators, switches and photodetectors. We also demonstrate systems that simultaneously combine many functionalities to achieve more complex building blocks. We propose novel silicon photonic devices, subsystems, network topologies and architectures to enable unprecedented performance of these photonic interconnection networks. Furthermore, the advantages of photonic interconnection networks extend far beyond the chip, offering advanced communication environments for memory systems, high-performance computing systems, and data centers.

  13. Network-based reading system for lung cancer screening CT

    NASA Astrophysics Data System (ADS)

    Fujino, Yuichi; Fujimura, Kaori; Nomura, Shin-ichiro; Kawashima, Harumi; Tsuchikawa, Megumu; Matsumoto, Toru; Nagao, Kei-ichi; Uruma, Takahiro; Yamamoto, Shinji; Takizawa, Hotaka; Kuroda, Chikazumi; Nakayama, Tomio

    2006-03-01

    This research aims to support chest computed tomography (CT) medical checkups to decrease the death rate by lung cancer. We have developed a remote cooperative reading system for lung cancer screening over the Internet, a secure transmission function, and a cooperative reading environment. It is called the Network-based Reading System. A telemedicine system involves many issues, such as network costs and data security if we use it over the Internet, which is an open network. In Japan, broadband access is widespread and its cost is the lowest in the world. We developed our system considering human machine interface and security. It consists of data entry terminals, a database server, a computer aided diagnosis (CAD) system, and some reading terminals. It uses a secure Digital Imaging and Communication in Medicine (DICOM) encrypting method and Public Key Infrastructure (PKI) based secure DICOM image data distribution. We carried out an experimental trial over the Japan Gigabit Network (JGN), which is the testbed for the Japanese next-generation network, and conducted verification experiments of secure screening image distribution, some kinds of data addition, and remote cooperative reading. We found that network bandwidth of about 1.5 Mbps enabled distribution of screening images and cooperative reading and that the encryption and image distribution methods we proposed were applicable to the encryption and distribution of general DICOM images via the Internet.

  14. Active system area networks for data intensive computations. Final report

    SciTech Connect

    2002-04-01

    The goal of the Active System Area Networks (ASAN) project is to develop hardware and software technologies for the implementation of active system area networks (ASANs). The use of the term ''active'' refers to the ability of the network interfaces to perform application-specific as well as system level computations in addition to their traditional role of data transfer. This project adopts the view that the network infrastructure should be an active computational entity capable of supporting certain classes of computations that would otherwise be performed on the host CPUs. The result is a unique network-wide programming model where computations are dynamically placed within the host CPUs or the NIs depending upon the quality of service demands and network/CPU resource availability. The projects seeks to demonstrate that such an approach is a better match for data intensive network-based applications and that the advent of low-cost powerful embedded processors and configurable hardware makes such an approach economically viable and desirable.

  15. Inferring connectivity in networked dynamical systems: Challenges using Granger causality

    NASA Astrophysics Data System (ADS)

    Lusch, Bethany; Maia, Pedro D.; Kutz, J. Nathan

    2016-09-01

    Determining the interactions and causal relationships between nodes in an unknown networked dynamical system from measurement data alone is a challenging, contemporary task across the physical, biological, and engineering sciences. Statistical methods, such as the increasingly popular Granger causality, are being broadly applied for data-driven discovery of connectivity in fields from economics to neuroscience. A common version of the algorithm is called pairwise-conditional Granger causality, which we systematically test on data generated from a nonlinear model with known causal network structure. Specifically, we simulate networked systems of Kuramoto oscillators and use the Multivariate Granger Causality Toolbox to discover the underlying coupling structure of the system. We compare the inferred results to the original connectivity for a wide range of parameters such as initial conditions, connection strengths, community structures, and natural frequencies. Our results show a significant systematic disparity between the original and inferred network, unless the true structure is extremely sparse or dense. Specifically, the inferred networks have significant discrepancies in the number of edges and the eigenvalues of the connectivity matrix, demonstrating that they typically generate dynamics which are inconsistent with the ground truth. We provide a detailed account of the dynamics for the Erdős-Rényi network model due to its importance in random graph theory and network science. We conclude that Granger causal methods for inferring network structure are highly suspect and should always be checked against a ground truth model. The results also advocate the need to perform such comparisons with any network inference method since the inferred connectivity results appear to have very little to do with the ground truth system.

  16. Inferring connectivity in networked dynamical systems: Challenges using Granger causality.

    PubMed

    Lusch, Bethany; Maia, Pedro D; Kutz, J Nathan

    2016-09-01

    Determining the interactions and causal relationships between nodes in an unknown networked dynamical system from measurement data alone is a challenging, contemporary task across the physical, biological, and engineering sciences. Statistical methods, such as the increasingly popular Granger causality, are being broadly applied for data-driven discovery of connectivity in fields from economics to neuroscience. A common version of the algorithm is called pairwise-conditional Granger causality, which we systematically test on data generated from a nonlinear model with known causal network structure. Specifically, we simulate networked systems of Kuramoto oscillators and use the Multivariate Granger Causality Toolbox to discover the underlying coupling structure of the system. We compare the inferred results to the original connectivity for a wide range of parameters such as initial conditions, connection strengths, community structures, and natural frequencies. Our results show a significant systematic disparity between the original and inferred network, unless the true structure is extremely sparse or dense. Specifically, the inferred networks have significant discrepancies in the number of edges and the eigenvalues of the connectivity matrix, demonstrating that they typically generate dynamics which are inconsistent with the ground truth. We provide a detailed account of the dynamics for the Erdős-Rényi network model due to its importance in random graph theory and network science. We conclude that Granger causal methods for inferring network structure are highly suspect and should always be checked against a ground truth model. The results also advocate the need to perform such comparisons with any network inference method since the inferred connectivity results appear to have very little to do with the ground truth system.

  17. NEMS (Nanoelectromechanicsl Systems) Networks: A Novel Validation Platform for Controlling Interconnected Dynamical Networks

    DTIC Science & Technology

    2015-08-01

    adaptive   network  topologies  (which,  for  example,  can  be  implemented  via  “ smart ”  edges  with  local  rules...16. SECURITY CLASSIFICATION OF: We review the experimental role NanoElectroMechanical System (NEMS) networks play vis a vis the MURI’s scientific...and validation goals which target new theoretical understanding of the dynamics of large-scale interconnected networks and their control. Our plans for

  18. Networked Robust Predictive Control Systems Design with Packet Loss

    NASA Astrophysics Data System (ADS)

    Nguyen, Quang T.; Veselý, Vojtech; Kozáková, Alena; Pakshin, Pavel

    2014-01-01

    The paper addresses problem of designing a robust output feedback model predictive control for uncertain linear systems over networks with packet-loss. The packet-loss process is arbitrary and bounded by the control horizon of model predictive control. Networked predictive control systems with packet loss are modeled as switched linear systems. This enables us to apply the theory of switched systems to establish the stability condition. The stabilizing controller design is based on sufficient robust stability conditions formulated as a solution of bilinear matrix inequality. Finally, a benchmark numerical example-double integrator is given to illustrate the effectiveness of the proposed method.

  19. Awareness System Implemented in the European Network

    NASA Astrophysics Data System (ADS)

    Jańıček, František; Jedinák, Martin; Šulc, Igor

    2014-09-01

    Transmission system in Slovakia is part of a synchronously interconnected system of continental Europe. Besides indisputable technical and economical benefits of cooperation many hazardous factors exist of fault condition spreading with impact on our system. Even today a system break-up escalated into a vast blackout is a real danger. European transmission system operators continually work on preventive measures and develop systems with a goal to handle critical situations. The ambition of the European Awareness System is to signalize the rise of these situations and also assist with system restoration

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

    PubMed

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

    2015-01-01

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

  1. Three neural network based sensor systems for environmental monitoring

    SciTech Connect

    Keller, P.E.; Kouzes, R.T.; Kangas, L.J.

    1994-05-01

    Compact, portable systems capable of quickly identifying contaminants in the field are of great importance when monitoring the environment. One of the missions of the Pacific Northwest Laboratory is to examine and develop new technologies for environmental restoration and waste management at the Hanford Site. In this paper, three prototype sensing systems are discussed. These prototypes are composed of sensing elements, data acquisition system, computer, and neural network implemented in software, and are capable of automatically identifying contaminants. The first system employs an array of tin-oxide gas sensors and is used to identify chemical vapors. The second system employs an array of optical sensors and is used to identify the composition of chemical dyes in liquids. The third system contains a portable gamma-ray spectrometer and is used to identify radioactive isotopes. In these systems, the neural network is used to identify the composition of the sensed contaminant. With a neural network, the intense computation takes place during the training process. Once the network is trained, operation consists of propagating the data through the network. Since the computation involved during operation consists of vector-matrix multiplication and application of look-up tables unknown samples can be rapidly identified in the field.

  2. THz frequency dynamics of network/guest atom systems : liquid water, clathrates, and network glasses.

    SciTech Connect

    Nakayama, T.; Materials Science Division

    2009-02-01

    Network/guest atom systems show peculiar dynamic behaviors at THz frequency region such as the plateau of thermal conductivities and the broad band spectra called the Boson peak. These are commonly realized in network/guest atom systems such as glasses, clathrates and even for liquid water. Though the phenomena are universal, there is no consistent view to explain these on the same basis. This paper, pointing out similar behaviors for these different systems, tries to present a unified view for these peculiar dynamics.

  3. A financial network perspective of financial institutions' systemic risk contributions

    NASA Astrophysics Data System (ADS)

    Huang, Wei-Qiang; Zhuang, Xin-Tian; Yao, Shuang; Uryasev, Stan

    2016-08-01

    This study considers the effects of the financial institutions' local topology structure in the financial network on their systemic risk contribution using data from the Chinese stock market. We first measure the systemic risk contribution with the Conditional Value-at-Risk (CoVaR) which is estimated by applying dynamic conditional correlation multivariate GARCH model (DCC-MVGARCH). Financial networks are constructed from dynamic conditional correlations (DCC) with graph filtering method of minimum spanning trees (MSTs). Then we investigate dynamics of systemic risk contributions of financial institution. Also we study dynamics of financial institution's local topology structure in the financial network. Finally, we analyze the quantitative relationships between the local topology structure and systemic risk contribution with panel data regression analysis. We find that financial institutions with greater node strength, larger node betweenness centrality, larger node closeness centrality and larger node clustering coefficient tend to be associated with larger systemic risk contributions.

  4. Representation of neural networks as Lotka-Volterra systems

    SciTech Connect

    Moreau, Yves; Vandewalle, Joos; Louies, Stephane; Brenig, Leon

    1999-03-22

    We study changes of coordinates that allow the representation of the ordinary differential equations describing continuous-time recurrent neural networks into differential equations describing predator-prey models--also called Lotka-Volterra systems. We transform the equations for the neural network first into quasi-monomial form, where we express the vector field of the dynamical system as a linear combination of products of powers of the variables. In practice, this transformation is possible only if the activation function is the hyperbolic tangent or the logistic sigmoied. From this quasi-monomial form, we can directly transform the system further into Lotka-Volterra equations. The resulting Lotka-Volterra system is of higher dimension than the original system, but the behavior of its first variables is equivalent to the behavior of the original neural network.

  5. Adaptive mechanism-based congestion control for networked systems

    NASA Astrophysics Data System (ADS)

    Liu, Zhi; Zhang, Yun; Chen, C. L. Philip

    2013-03-01

    In order to assure the communication quality in network systems with heavy traffic and limited bandwidth, a new ATRED (adaptive thresholds random early detection) congestion control algorithm is proposed for the congestion avoidance and resource management of network systems. Different to the traditional AQM (active queue management) algorithms, the control parameters of ATRED are not configured statically, but dynamically adjusted by the adaptive mechanism. By integrating with the adaptive strategy, ATRED alleviates the tuning difficulty of RED (random early detection) and shows a better control on the queue management, and achieve a more robust performance than RED under varying network conditions. Furthermore, a dynamic transmission control protocol-AQM control system using ATRED controller is introduced for the systematic analysis. It is proved that the stability of the network system can be guaranteed when the adaptive mechanism is finely designed. Simulation studies show the proposed ATRED algorithm achieves a good performance in varying network environments, which is superior to the RED and Gentle-RED algorithm, and providing more reliable service under varying network conditions.

  6. Pattern reverberation in networks of excitable systems with connection delays

    NASA Astrophysics Data System (ADS)

    Lücken, Leonhard; Rosin, David P.; Worlitzer, Vasco M.; Yanchuk, Serhiy

    2017-01-01

    We consider the recurrent pulse-coupled networks of excitable elements with delayed connections, which are inspired by the biological neural networks. If the delays are tuned appropriately, the network can either stay in the steady resting state, or alternatively, exhibit a desired spiking pattern. It is shown that such a network can be used as a pattern-recognition system. More specifically, the application of the correct pattern as an external input to the network leads to a self-sustained reverberation of the encoded pattern. In terms of the coupling structure, the tolerance and the refractory time of the individual systems, we determine the conditions for the uniqueness of the sustained activity, i.e., for the functionality of the network as an unambiguous pattern detector. We point out the relation of the considered systems with cyclic polychronous groups and show how the assumed delay configurations may arise in a self-organized manner when a spike-time dependent plasticity of the connection delays is assumed. As excitable elements, we employ the simplistic coincidence detector models as well as the Hodgkin-Huxley neuron models. Moreover, the system is implemented experimentally on a Field-Programmable Gate Array.

  7. Pattern reverberation in networks of excitable systems with connection delays.

    PubMed

    Lücken, Leonhard; Rosin, David P; Worlitzer, Vasco M; Yanchuk, Serhiy

    2017-01-01

    We consider the recurrent pulse-coupled networks of excitable elements with delayed connections, which are inspired by the biological neural networks. If the delays are tuned appropriately, the network can either stay in the steady resting state, or alternatively, exhibit a desired spiking pattern. It is shown that such a network can be used as a pattern-recognition system. More specifically, the application of the correct pattern as an external input to the network leads to a self-sustained reverberation of the encoded pattern. In terms of the coupling structure, the tolerance and the refractory time of the individual systems, we determine the conditions for the uniqueness of the sustained activity, i.e., for the functionality of the network as an unambiguous pattern detector. We point out the relation of the considered systems with cyclic polychronous groups and show how the assumed delay configurations may arise in a self-organized manner when a spike-time dependent plasticity of the connection delays is assumed. As excitable elements, we employ the simplistic coincidence detector models as well as the Hodgkin-Huxley neuron models. Moreover, the system is implemented experimentally on a Field-Programmable Gate Array.

  8. Multiple neural network approaches to clinical expert systems

    NASA Astrophysics Data System (ADS)

    Stubbs, Derek F.

    1990-08-01

    We briefly review the concept of computer aided medical diagnosis and more extensively review the the existing literature on neural network applications in the field. Neural networks can function as simple expert systems for diagnosis or prognosis. Using a public database we develop a neural network for the diagnosis of a major presenting symptom while discussing the development process and possible approaches. MEDICAL EXPERTS SYSTEMS COMPUTER AIDED DIAGNOSIS Biomedicine is an incredibly diverse and multidisciplinary field and it is not surprising that neural networks with their many applications are finding more and more applications in the highly non-linear field of biomedicine. I want to concentrate on neural networks as medical expert systems for clinical diagnosis or prognosis. Expert Systems started out as a set of computerized " ifthen" rules. Everything was reduced to boolean logic and the promised land of computer experts was said to be in sight. It never came. Why? First the computer code explodes as the number of " ifs" increases. All the " ifs" have to interact. Second experts are not very good at reducing expertise to language. It turns out that experts recognize patterns and have non-verbal left-brain intuition decision processes. Third learning by example rather than learning by rule is the way natural brains works and making computers work by rule-learning is hideously labor intensive. Neural networks can learn from example. They learn the results

  9. Network thermodynamics and complexity: a transition to relational systems theory.

    PubMed

    Mikulecky, D C

    2001-07-01

    Most systems of interest in today's world are highly structured and highly interactive. They cannot be reduced to simple components without losing a great deal of their system identity. Network thermodynamics is a marriage of classical and non-equilibrium thermodynamics along with network theory and kinetics to provide a practical framework for handling these systems. The ultimate result of any network thermodynamic model is still a set of state vector equations. But these equations are built in a new informative way so that information about the organization of the system is identifiable in the structure of the equations. The domain of network thermodynamics is all of physical systems theory. By using the powerful circuit simulator, the Simulation Program with Integrated Circuit Emphasis (SPICE), as a general systems simulator, any highly non-linear stiff system can be simulated. Furthermore, the theoretical findings of network thermodynamics are important new contributions. The contribution of a metric structure to thermodynamics compliments and goes beyond other recent work in this area. The application of topological reasoning through Tellegen's theorem shows that a mathematical structure exists into which all physical systems can be represented canonically. The old results in non-equilibrium thermodynamics due to Onsager can be reinterpreted and extended using these new, more holistic concepts about systems. Some examples are given. These are but a few of the many applications of network thermodynamics that have been proven to extend our capacity for handling the highly interactive, non-linear systems that populate both biology and chemistry. The presentation is carried out in the context of the recent growth of the field of complexity science. In particular, the context used for this discussion derives from the work of the mathematical biologist, Robert Rosen.

  10. Reconstruction of financial networks for robust estimation of systemic risk

    NASA Astrophysics Data System (ADS)

    Mastromatteo, Iacopo; Zarinelli, Elia; Marsili, Matteo

    2012-03-01

    In this paper we estimate the propagation of liquidity shocks through interbank markets when the information about the underlying credit network is incomplete. We show that techniques such as maximum entropy currently used to reconstruct credit networks severely underestimate the risk of contagion by assuming a trivial (fully connected) topology, a type of network structure which can be very different from the one empirically observed. We propose an efficient message-passing algorithm to explore the space of possible network structures and show that a correct estimation of the network degree of connectedness leads to more reliable estimations for systemic risk. Such an algorithm is also able to produce maximally fragile structures, providing a practical upper bound for the risk of contagion when the actual network structure is unknown. We test our algorithm on ensembles of synthetic data encoding some features of real financial networks (sparsity and heterogeneity), finding that more accurate estimations of risk can be achieved. Finally we find that this algorithm can be used to control the amount of information that regulators need to require from banks in order to sufficiently constrain the reconstruction of financial networks.

  11. Stochastic S-system modeling of gene regulatory network.

    PubMed

    Chowdhury, Ahsan Raja; Chetty, Madhu; Evans, Rob

    2015-10-01

    Microarray gene expression data can provide insights into biological processes at a system-wide level and is commonly used for reverse engineering gene regulatory networks (GRN). Due to the amalgamation of noise from different sources, microarray expression profiles become inherently noisy leading to significant impact on the GRN reconstruction process. Microarray replicates (both biological and technical), generated to increase the reliability of data obtained under noisy conditions, have limited influence in enhancing the accuracy of reconstruction . Therefore, instead of the conventional GRN modeling approaches which are deterministic, stochastic techniques are becoming increasingly necessary for inferring GRN from noisy microarray data. In this paper, we propose a new stochastic GRN model by investigating incorporation of various standard noise measurements in the deterministic S-system model. Experimental evaluations performed for varying sizes of synthetic network, representing different stochastic processes, demonstrate the effect of noise on the accuracy of genetic network modeling and the significance of stochastic modeling for GRN reconstruction . The proposed stochastic model is subsequently applied to infer the regulations among genes in two real life networks: (1) the well-studied IRMA network, a real-life in-vivo synthetic network constructed within the Saccharomyces cerevisiae yeast, and (2) the SOS DNA repair network in Escherichia coli.

  12. NNETS - NEURAL NETWORK ENVIRONMENT ON A TRANSPUTER SYSTEM

    NASA Technical Reports Server (NTRS)

    Villarreal, J.

    1994-01-01

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

  13. A Hybrid Authentication and Authorization Process for Control System Networks

    SciTech Connect

    Manz, David O.; Edgar, Thomas W.; Fink, Glenn A.

    2010-08-25

    Convergence of control system and IT networks require that security, privacy, and trust be addressed. Trust management continues to plague traditional IT managers and is even more complex when extended into control system networks, with potentially millions of entities, a mission that requires 100% availability. Yet these very networks necessitate a trusted secure environment where controllers and managers can be assured that the systems are secure and functioning properly. We propose a hybrid authentication management protocol that addresses the unique issues inherent within control system networks, while leveraging the considerable research and momentum in existing IT authentication schemes. Our hybrid authentication protocol for control systems provides end device to end device authentication within a remote station and between remote stations and control centers. Additionally, the hybrid protocol is failsafe and will not interrupt communication or control of vital systems in a network partition or device failure. Finally, the hybrid protocol is resilient to transitory link loss and can operate in an island mode until connectivity is reestablished.

  14. Effects of Route Guidance Systems on Small-World Networks

    NASA Astrophysics Data System (ADS)

    Wu, Jian-Jun; Sun, Hui-Jun; Gao, Zi-You; Li, Shu-Bin

    The route guidance systems (RGS) are efficient in alleviating traffic congestion and reducing transit time of transportation networks. This paper studies the effects of RGS on performance of variably weighted small-world networks. The properties of the average shortest path length, the maximum degree, and the largest betweenness, as important indices for characterizing the network structure in complex networks, are simulated. Results show that there is an optimal guided rate of RGS to minimize the total system cost and the average shortest path length, and proper RGS can reduce the load of the node with maximum degree or largest betweenness. In addition, we found that the load distribution of nodes guided by RGS decay as the power laws which is very important for us to understand and control traffic congestion feasible.

  15. Implementations of learning control systems using neural networks

    NASA Technical Reports Server (NTRS)

    Sartori, Michael A.; Antsaklis, Panos J.

    1992-01-01

    The systematic storage in neural networks of prior information to be used in the design of various control subsystems is investigated. Assuming that the prior information is available in a certain form (namely, input/output data points and specifications between the data points), a particular neural network and a corresponding parameter design method are introduced. The proposed neural network addresses the issue of effectively using prior information in the areas of dynamical system (plant and controller) modeling, fault detection and identification, information extraction, and control law scheduling.

  16. Improved Stabilization Method for Lurie Networked Control Systems

    PubMed Central

    Zeng, Hong-Bing; Xiao, Shen-Ping; Yu, Fei

    2014-01-01

    The problem of stabilization of Lurie networked control systems (NCSs) is investigated in this paper. The network-induced delays in NCSs are assumed to be time-varying and bounded. By utilizing a reciprocally convex technique to consider the relationship between the network-induced delay and its varying interval, a new absolute stability condition is derived in terms of linear matrix inequalities (LMIs). Based on the obtained condition, an improved cone complementary linearisation (CCL) iteration algorithm is presented to design a state feedback controller. The effectiveness of the proposed method is verified by a numerical example. PMID:24892090

  17. Integrated multimedia information system on interactive CATV network

    NASA Astrophysics Data System (ADS)

    Lee, Meng-Huang; Chang, Shin-Hung

    1998-10-01

    In the current CATV system architectures, they provide one- way delivery of a common menu of entertainment to all the homes through the cable network. Through the technologies evolution, the interactive services (or two-way services) can be provided in the cable TV systems. They can supply customers with individualized programming and support real- time two-way communications. With a view to the service type changed from the one-way delivery systems to the two-way interactive systems, `on demand services' is a distinct feature of multimedia systems. In this paper, we present our work of building up an integrated multimedia system on interactive CATV network in Shih Chien University. Besides providing the traditional analog TV programming from the cable operator, we filter some channels to reserve them as our campus information channels. In addition to the analog broadcasting channel, the system also provides the interactive digital multimedia services, e.g. Video-On- Demand (VOD), Virtual Reality, BBS, World-Wide-Web, and Internet Radio Station. These two kinds of services are integrated in a CATV network by the separation of frequency allocation for the analog broadcasting service and the digital interactive services. Our ongoing work is to port our previous work of building up a VOD system conformed to DAVIC standard (for inter-operability concern) on Ethernet network into the current system.

  18. Enhanced networks operations using the X Window System

    NASA Technical Reports Server (NTRS)

    Linares, Irving

    1993-01-01

    We propose an X Window Graphical User Interface (GUI) which is tailored to the operations of NASA GSFC's Network Control Center (NCC), the NASA Ground Terminal (NGT), the White Sands Ground Terminal (WSGT), and the Second Tracking and Data Relay Satellite System (TDRSS) Ground Terminal (STGT). The proposed GUI can also be easily extended to other Ground Network (GN) Tracking Stations due to its standardized nature.

  19. State of the art survey of network operating systems development

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The results of the State-of-the-Art Survey of Network Operating Systems (NOS) performed for Goddard Space Flight Center are presented. NOS functional characteristics are presented in terms of user communication data migration, job migration, network control, and common functional categories. Products (current or future) as well as research and prototyping efforts are summarized. The NOS products which are revelant to the space station and its activities are evaluated.

  20. Component criticality in failure cascade processes of network systems.

    PubMed

    Zio, Enrico; Sansavini, Giovanni

    2011-08-01

    In this work, specific indicators are used to characterize the criticality of components in a network system with respect to their contribution to failure cascade processes. A realistic-size network is considered as reference case study. Three different models of cascading failures are analyzed, differing both on the failure load distribution logic and on the cascade triggering event. The criticality indicators are compared to classical measures of topological centrality to identify the one most characteristic of the cascade processes considered.

  1. Documentation for the token ring network simulation system

    NASA Technical Reports Server (NTRS)

    Peden, Jeffery H.; Weaver, Alfred C.

    1990-01-01

    A manual is presented which describes the language features of the Token Ring Network Simulation System. The simulation system is a powerful simulation tool for token ring networks which allows the specification of various Medium Access Control (MAC) layer protocols as well as the specification of various features of upper layer ISO protocols. In addition to these features, it also allows the user to specify message and station classes virtually to any degree of detail desired. The choice of a language instead of an interactive system to specify network parameters was dictated by both flexibility and time considerations. The language was developed specifically for the simulation system, and is very simple. It is also user friendly in that language elements which do not apply to the case at hand are ignored rather than treated as errors.

  2. Smartphone qualification & linux-based tools for CubeSat computing payloads

    NASA Astrophysics Data System (ADS)

    Bridges, C. P.; Yeomans, B.; Iacopino, C.; Frame, T. E.; Schofield, A.; Kenyon, S.; Sweeting, M. N.

    Modern computers are now far in advance of satellite systems and leveraging of these technologies for space applications could lead to cheaper and more capable spacecraft. Together with NASA AMES's PhoneSat, the STRaND-1 nanosatellite team has been developing and designing new ways to include smart-phone technologies to the popular CubeSat platform whilst mitigating numerous risks. Surrey Space Centre (SSC) and Surrey Satellite Technology Ltd. (SSTL) have led in qualifying state-of-the-art COTS technologies and capabilities - contributing to numerous low-cost satellite missions. The focus of this paper is to answer if 1) modern smart-phone software is compatible for fast and low-cost development as required by CubeSats, and 2) if the components utilised are robust to the space environment. The STRaND-1 smart-phone payload software explored in this paper is united using various open-source Linux tools and generic interfaces found in terrestrial systems. A major result from our developments is that many existing software and hardware processes are more than sufficient to provide autonomous and operational payload object-to-object and file-based management solutions. The paper will provide methodologies on the software chains and tools used for the STRaND-1 smartphone computing platform, the hardware built with space qualification results (thermal, thermal vacuum, and TID radiation), and how they can be implemented in future missions.

  3. Applying New Network Security Technologies to SCADA Systems.

    SciTech Connect

    Hurd, Steven A; Stamp, Jason Edwin; Duggan, David P; Chavez, Adrian R.

    2006-11-01

    Supervisory Control and Data Acquisition (SCADA) systems for automation are very important for critical infrastructure and manufacturing operations. They have been implemented to work in a number of physical environments using a variety of hardware, software, networking protocols, and communications technologies, often before security issues became of paramount concern. To offer solutions to security shortcomings in the short/medium term, this project was to identify technologies used to secure "traditional" IT networks and systems, and then assess their efficacy with respect to SCADA systems. These proposed solutions must be relatively simple to implement, reliable, and acceptable to SCADA owners and operators. 4This page intentionally left blank.

  4. Research on image autofocus system based on neural network

    NASA Astrophysics Data System (ADS)

    Chen, Guojin; Liu, Bin; Gong, Ye; Xu, Guohua; Shi, Huli

    2003-09-01

    AF (auto-focus) becomes a very important function in many kinds of photoelectricity imaging systems. The popular AF is realized by means of measuring distance. In this paper, a new AF means is presented, which is realized by a neural network. Because the NN (neural network) has the capacity of non-linear processing, it can be used to estimate image's definition and adjust PID controller's parameters. When such a NN is embedded in an AF system, the system will have the features of real time, high veracity and self-adaptation.

  5. Networks and webs in ecosystems and financial systems.

    PubMed

    May, Robert M

    2013-03-28

    This paper briefly outlines our growing understanding of the relationships between the network structure of ecological networks--both in mathematical models and in the real world--and their consequent dynamical properties. These are interesting, inter alia, because they affect the system's ability to withstand disturbance, whether natural or human-created. The paper also sketches recent interest in the potential relevance of this work to 'systemic risk' and regulatory measures in banking systems, emphasizing the similarities and differences. I conclude with some cautions against drawing excessively general conclusions from any such models.

  6. FPGA implementation of a pyramidal Weightless Neural Networks learning system.

    PubMed

    Al-Alawi, Raida

    2003-08-01

    A hardware architecture of a Probabilistic Logic Neuron (PLN) is presented. The suggested model facilitates the on-chip learning of pyramidal Weightless Neural Networks using a modified probabilistic search reward/penalty training algorithm. The penalization strategy of the training algorithm depends on a predefined parameter called the probabilistic search interval. A complete Weightless Neural Network (WNN) learning system is modeled and implemented on Xilinx XC4005E Field Programmable Gate Array (FPGA), allowing its architecture to be configurable. Various experiments have been conducted to examine the feasibility and performance of the WNN learning system. Results show that the system has a fast convergence rate and good generalization ability.

  7. Academic Support Systems: A Networked Approach.

    ERIC Educational Resources Information Center

    Klingenstein, Kenneth

    1984-01-01

    Academic support systems are characterized as those activities that center around a dean's office--office automation/information systems, institutional research and electronic communication. The basic and design and implementation issues that are encountered in providing these support systems are examined. (Author/MLW)

  8. Easy Access: Auditing the System Network

    ERIC Educational Resources Information Center

    Wiech, Dean

    2013-01-01

    In today's electronic learning environment, access to appropriate systems and data is of the utmost importance to students, faculty, and staff. Without proper access to the school's internal systems, teachers could be prevented from logging on to an online learning system and students might be unable to submit course work to an online…

  9. A Learning System for Discriminating Variants of Malicious Network Traffic

    SciTech Connect

    Beaver, Justin M; Symons, Christopher T; Gillen, Rob

    2013-01-01

    Modern computer network defense systems rely primarily on signature-based intrusion detection tools, which generate alerts when patterns that are pre-determined to be malicious are encountered in network data streams. Signatures are created reactively, and only after in-depth manual analysis of a network intrusion. There is little ability for signature-based detectors to identify intrusions that are new or even variants of an existing attack, and little ability to adapt the detectors to the patterns unique to a network environment. Due to these limitations, the need exists for network intrusion detection techniques that can more comprehensively address both known unknown networkbased attacks and can be optimized for the target environment. This work describes a system that leverages machine learning to provide a network intrusion detection capability that analyzes behaviors in channels of communication between individual computers. Using examples of malicious and non-malicious traffic in the target environment, the system can be trained to discriminate between traffic types. The machine learning provides insight that would be difficult for a human to explicitly code as a signature because it evaluates many interdependent metrics simultaneously. With this approach, zero day detection is possible by focusing on similarity to known traffic types rather than mining for specific bit patterns or conditions. This also reduces the burden on organizations to account for all possible attack variant combinations through signatures. The approach is presented along with results from a third-party evaluation of its performance.

  10. Weather network computer to control deck-heating system

    SciTech Connect

    Roe, A.

    1997-04-07

    A ground-source heating system for bridge deicing is briefly described in this article. The deck heating system will be controlled by the Oklahoma state weather network. Warm ground air will be pumped from more than 100 boreholes at least 200 feet deep. The heat transfer fluid, possibly propylene glycol, will be circulated through a sealed tube system in the bridge deck. Costs are estimated at $200,000 for the heating system and $840,000 for the total redecking project.

  11. Emergence of hierarchical networks and polysynchronous behaviour in simple adaptive systems

    NASA Astrophysics Data System (ADS)

    Botella-Soler, V.; Glendinning, P.

    2012-03-01

    We describe the dynamics of a simple adaptive network. The network architecture evolves to a number of disconnected components on which the dynamics is characterized by the possibility of differently synchronized nodes within the same network (polysynchronous states). These systems may have implications for the evolutionary emergence of polysynchrony and hierarchical networks in physical or biological systems modeled by adaptive networks.

  12. Neural Network Based Intrusion Detection System for Critical Infrastructures

    SciTech Connect

    Todd Vollmer; Ondrej Linda; Milos Manic

    2009-07-01

    Resiliency and security in control systems such as SCADA and Nuclear plant’s in today’s world of hackers and malware are a relevant concern. Computer systems used within critical infrastructures to control physical functions are not immune to the threat of cyber attacks and may be potentially vulnerable. Tailoring an intrusion detection system to the specifics of critical infrastructures can significantly improve the security of such systems. The IDS-NNM – Intrusion Detection System using Neural Network based Modeling, is presented in this paper. The main contributions of this work are: 1) the use and analyses of real network data (data recorded from an existing critical infrastructure); 2) the development of a specific window based feature extraction technique; 3) the construction of training dataset using randomly generated intrusion vectors; 4) the use of a combination of two neural network learning algorithms – the Error-Back Propagation and Levenberg-Marquardt, for normal behavior modeling. The presented algorithm was evaluated on previously unseen network data. The IDS-NNM algorithm proved to be capable of capturing all intrusion attempts presented in the network communication while not generating any false alerts.

  13. Physical-layer network coding in coherent optical OFDM systems.

    PubMed

    Guan, Xun; Chan, Chun-Kit

    2015-04-20

    We present the first experimental demonstration and characterization of the application of optical physical-layer network coding in coherent optical OFDM systems. It combines two optical OFDM frames to share the same link so as to enhance system throughput, while individual OFDM frames can be recovered with digital signal processing at the destined node.

  14. Automated Bilingual Circulation System Using PC Local Area Networks.

    ERIC Educational Resources Information Center

    Iskanderani, A. I.; Anwar, M. A.

    1992-01-01

    Describes a local automated bilingual circulation system using personal computers in a local area network that was developed at King Abdulaziz University (Saudi Arabia) for Arabic and English materials. Topics addressed include the system structure, hardware, major features, storage requirements, and costs. (nine references) (LRW)

  15. Installing an Integrated Information System in a Centralized Network.

    ERIC Educational Resources Information Center

    Mendelson, Andrew D.

    1992-01-01

    Many schools are looking at ways to centralize the distribution and retrieval of video, voice, and data transmissions in an integrate information system (IIS). A centralized system offers greater control of hardware and software. Describes media network planning to retrofit an Illinois' high school with a fiber optic-based IIS. (MLF)

  16. Principles of E-network modelling of heterogeneous systems

    NASA Astrophysics Data System (ADS)

    Tarakanov, D.; Tsapko, I.; Tsapko, S.; Buldygin, R.

    2016-04-01

    The present article is concerned with the analytical and simulation modelling of heterogeneous technical systems using E-network mathematical apparatus (the expansion of Petri nets). The distinguishing feature of the given system is the presence of the module6 which identifies the parameters of the controlled object as well as the external environment.

  17. FIPA agent based network distributed control system

    SciTech Connect

    D. Abbott; V. Gyurjyan; G. Heyes; E. Jastrzembski; C. Timmer; E. Wolin

    2003-03-01

    A control system with the capabilities to combine heterogeneous control systems or processes into a uniform homogeneous environment is discussed. This dynamically extensible system is an example of the software system at the agent level of abstraction. This level of abstraction considers agents as atomic entities that communicate to implement the functionality of the control system. Agents' engineering aspects are addressed by adopting the domain independent software standard, formulated by FIPA. Jade core Java classes are used as a FIPA specification implementation. A special, lightweight, XML RDFS based, control oriented, ontology markup language is developed to standardize the description of the arbitrary control system data processor. Control processes, described in this language, are integrated into the global system at runtime, without actual programming. Fault tolerance and recovery issues are also addressed.

  18. Host Event Based Network Monitoring

    SciTech Connect

    Jonathan Chugg

    2013-01-01

    The purpose of INL’s research on this project is to demonstrate the feasibility of a host event based network monitoring tool and the effects on host performance. Current host based network monitoring tools work on polling which can miss activity if it occurs between polls. Instead of polling, a tool could be developed that makes use of event APIs in the operating system to receive asynchronous notifications of network activity. Analysis and logging of these events will allow the tool to construct the complete real-time and historical network configuration of the host while the tool is running. This research focused on three major operating systems commonly used by SCADA systems: Linux, WindowsXP, and Windows7. Windows 7 offers two paths that have minimal impact on the system and should be seriously considered. First is the new Windows Event Logging API, and, second, Windows 7 offers the ALE API within WFP. Any future work should focus on these methods.

  19. Systems chemistry: logic gates, arithmetic units, and network motifs in small networks.

    PubMed

    Wagner, Nathaniel; Ashkenasy, Gonen

    2009-01-01

    A mixture of molecules can be regarded as a network if all the molecular components participate in some kind of interaction with other molecules--either physical or functional interactions. Template-assisted ligation reactions that direct replication processes can serve as the functional elements that connect two members of a chemical network. In such a process, the template does not necessarily catalyze its own formation, but rather the formation of another molecule, which in turn can operate as a template for reactions within the network medium. It was postulated that even networks made up of small numbers of molecules possess a wealth of molecular information sufficient to perform rather complex behavior. To probe this assumption, we have constructed virtual arrays consisting of three replicating molecules, in which dimer templates are capable of catalyzing reactants to form additional templates. By using realistic parameters from peptides or DNA replication experiments, we simulate the construction of various functional motifs within the networks. Specifically, we have designed and implemented each of the three-element Boolean logic gates, and show how these networks are assembled from four basic "building blocks". We also show how the catalytic pathways can be wired together to perform more complex arithmetic units and network motifs, such as the half adder and half subtractor computational modules, and the coherent feed-forward loop network motifs under different sets of parameters. As in previous studies of chemical networks, some of the systems described display behavior that would be difficult to predict without the numerical simulations. Furthermore, the simulations reveal trends and characteristics that should be useful as "recipes" for future design of experimental functional motifs and for potential integration into modular circuits and molecular computation devices.

  20. Revealing and analyzing networks of environmental systems

    NASA Astrophysics Data System (ADS)

    Eveillard, D.; Bittner, L.; Chaffron, S.; Guidi, L.; Raes, J.; Karsenti, E.; Bowler, C.; Gorsky, G.

    2015-12-01

    Understanding the interactions between microbial communities and their environment well enough to be able to predict diversity on the basis of physicochemical parameters is a fundamental pursuit of microbial ecology that still eludes us. However, modeling microbial communities is a complicated task, because (i) communities are complex, (ii) most are described qualitatively, and (iii) quantitative understanding of the way communities interacts with their surroundings remains incomplete. Within this seminar, we will illustrate two complementary approaches that aim to overcome these points in different manners. First, we will present a network analysis that focus on the biological carbon pump in the global ocean. The biological carbon pump is the process by which photosynthesis transforms CO2 to organic carbon sinking to the deep-ocean as particles where it is sequestered. While the intensity of the pump correlate to plankton community composition, the underlying ecosystem structure and interactions driving this process remain largely uncharacterized Here we use environmental and metagenomic data gathered during the Tara Oceans expedition to improve understanding of these drivers. We show that specific plankton communities correlate with carbon export and highlight unexpected and overlooked taxa such as Radiolaria, alveolate parasites and bacterial pathogens, as well as Synechococcus and their phages, as key players in the biological pump. Additionally, we show that the abundances of just a few bacterial and viral genes predict most of the global ocean carbon export's variability. Together these findings help elucidate ecosystem drivers of the biological carbon pump and present a case study for scaling from genes-to-ecosystems. Second, we will show preliminary results on a probabilistic modeling that predicts microbial community structure across observed physicochemical data, from a putative network and partial quantitative knowledge. This modeling shows that, despite

  1. Integration of SPS with utility system networks

    NASA Technical Reports Server (NTRS)

    Kaupang, B. M.

    1980-01-01

    The integration of Satellite Power System (SPS) power in electric utility power systems is discussed. Specifically, the nature of the power output variations from the spacecraft to the rectenna, the operational characteristics of the rectenna power, and the impacts on the electric utility system from utilizing SPS power to serve part of the system load are treated. It is concluded that if RF beam control is an acceptable method for power control, and that the site distribution of SPS rectennas do not cause a very high local penetration (40 to 50%), SPS may be integrated into electric utility system with a few negative impacts. Increased regulating duty on the conventional generation, and a potential impact on system reliability for SPS penetration in excess of about 25% appear to be two areas of concern.

  2. Delayed standard neural network models for control systems.

    PubMed

    Liu, Meiqin

    2007-09-01

    In order to conveniently analyze the stability of recurrent neural networks (RNNs) and successfully synthesize the controllers for nonlinear systems, similar to the nominal model in linear robust control theory, the novel neural network model, named delayed standard neural network model (DSNNM) is presented, which is the interconnection of a linear dynamic system and a bounded static delayed (or nondelayed) nonlinear operator. By combining a number of different Lyapunov functionals with S-procedure, some useful criteria of global asymptotic stability and global exponential stability for the continuous-time DSNNMs (CDSNNMs) and discrete-time DSNNMs (DDSNNMs) are derived, whose conditions are formulated as linear matrix inequalities (LMIs). Based on the stability analysis, some state-feedback control laws for the DSNNM with input and output are designed to stabilize the closed-loop systems. Most RNNs and neurocontrol nonlinear systems with (or without) time delays can be transformed into the DSNNMs to be stability-analyzed or stabilization-synthesized in a unified way. In this paper, the DSNNMs are applied to analyzing the stability of the continuous-time and discrete-time RNNs with or without time delays, and synthesizing the state-feedback controllers for the chaotic neural-network-system and discrete-time nonlinear system. It turns out that the DSNNM makes the stability conditions of the RNNs easily verified, and provides a new idea for the synthesis of the controllers for the nonlinear systems.

  3. Dynamic Business Networks: A Headache for Sustainable Systems Interoperability

    NASA Astrophysics Data System (ADS)

    Agostinho, Carlos; Jardim-Goncalves, Ricardo

    Collaborative networked environments emerged with the spread of the internet, contributing to overcome past communication barriers, and identifying interoperability as an essential property. When achieved seamlessly, efficiency is increased in the entire product life cycle. Nowadays, most organizations try to attain interoperability by establishing peer-to-peer mappings with the different partners, or in optimized networks, by using international standard models as the core for information exchange. In current industrial practice, mappings are only defined once, and the morphisms that represent them, are hardcoded in the enterprise systems. This solution has been effective for static environments, where enterprise and product models are valid for decades. However, with an increasingly complex and dynamic global market, models change frequently to answer new customer requirements. This paper draws concepts from the complex systems science and proposes a framework for sustainable systems interoperability in dynamic networks, enabling different organizations to evolve at their own rate.

  4. An artificial neural network controller for intelligent transportation systems applications

    SciTech Connect

    Vitela, J.E.; Hanebutte, U.R.; Reifman, J.

    1996-04-01

    An Autonomous Intelligent Cruise Control (AICC) has been designed using a feedforward artificial neural network, as an example for utilizing artificial neural networks for nonlinear control problems arising in intelligent transportation systems applications. The AICC is based on a simple nonlinear model of the vehicle dynamics. A Neural Network Controller (NNC) code developed at Argonne National Laboratory to control discrete dynamical systems was used for this purpose. In order to test the NNC, an AICC-simulator containing graphical displays was developed for a system of two vehicles driving in a single lane. Two simulation cases are shown, one involving a lead vehicle with constant velocity and the other a lead vehicle with varying acceleration. More realistic vehicle dynamic models will be considered in future work.

  5. A Flexible, Open, Decentralized System for Digital Pathology Networks

    PubMed Central

    SMITH, David E.; KUMARAGURUPARAN, Gowri; CHERVENAK, Ann; LEWIS, Anne D.; HYDE, Dallas M.; KESSELMAN, Carl

    2014-01-01

    High-resolution digital imaging is enabling digital archiving and sharing of digitized microscopy slides and new methods for digital pathology. Collaborative research centers, outsourced medical services, and multi-site organizations stand to benefit from sharing pathology data in a digital pathology network. Yet significant technological challenges remain due to the large size and volume of digitized whole slide images. While information systems do exist for managing local pathology laboratories, they tend to be oriented toward narrow clinical use cases or offer closed ecosystems around proprietary formats. Few solutions exist for networking digital pathology operations. Here we present a system architecture and implementation of a digital pathology network and share results from a production system that federates major research centers. PMID:22941985

  6. Neural Network Control of a Magnetically Suspended Rotor System

    NASA Technical Reports Server (NTRS)

    Choi, Benjamin; Brown, Gerald; Johnson, Dexter

    1997-01-01

    Abstract Magnetic bearings offer significant advantages because of their noncontact operation, which can reduce maintenance. Higher speeds, no friction, no lubrication, weight reduction, precise position control, and active damping make them far superior to conventional contact bearings. However, there are technical barriers that limit the application of this technology in industry. One of them is the need for a nonlinear controller that can overcome the system nonlinearity and uncertainty inherent in magnetic bearings. This paper discusses the use of a neural network as a nonlinear controller that circumvents system nonlinearity. A neural network controller was well trained and successfully demonstrated on a small magnetic bearing rig. This work demonstrated the feasibility of using a neural network to control nonlinear magnetic bearings and systems with unknown dynamics.

  7. Two classes of bipartite networks: nested biological and social systems.

    PubMed

    Burgos, Enrique; Ceva, Horacio; Hernández, Laura; Perazzo, R P J; Devoto, Mariano; Medan, Diego

    2008-10-01

    Bipartite graphs have received some attention in the study of social networks and of biological mutualistic systems. A generalization of a previous model is presented, that evolves the topology of the graph in order to optimally account for a given contact preference rule between the two guilds of the network. As a result, social and biological graphs are classified as belonging to two clearly different classes. Projected graphs, linking the agents of only one guild, are obtained from the original bipartite graph. The corresponding evolution of its statistical properties is also studied. An example of a biological mutualistic network is analyzed in detail, and it is found that the model provides a very good fitting of all the main statistical features. The model also provides a proper qualitative description of the same features observed in social webs, suggesting the possible reasons underlying the difference in the organization of these two kinds of bipartite networks.

  8. BioSMACK: a linux live CD for genome-wide association analyses.

    PubMed

    Hong, Chang Bum; Kim, Young Jin; Moon, Sanghoon; Shin, Young-Ah; Go, Min Jin; Kim, Dong-Joon; Lee, Jong-Young; Cho, Yoon Shin

    2012-01-01

    Recent advances in high-throughput genotyping technologies have enabled us to conduct a genome-wide association study (GWAS) on a large cohort. However, analyzing millions of single nucleotide polymorphisms (SNPs) is still a difficult task for researchers conducting a GWAS. Several difficulties such as compatibilities and dependencies are often encountered by researchers using analytical tools, during the installation of software. This is a huge obstacle to any research institute without computing facilities and specialists. Therefore, a proper research environment is an urgent need for researchers working on GWAS. We developed BioSMACK to provide a research environment for GWAS that requires no configuration and is easy to use. BioSMACK is based on the Ubuntu Live CD that offers a complete Linux-based operating system environment without installation. Moreover, we provide users with a GWAS manual consisting of a series of guidelines for GWAS and useful examples. BioSMACK is freely available at http://ksnp.cdc. go.kr/biosmack.

  9. Systemic risk and heterogeneous leverage in banking networks

    NASA Astrophysics Data System (ADS)

    Kuzubaş, Tolga Umut; Saltoğlu, Burak; Sever, Can

    2016-11-01

    This study probes systemic risk implications of leverage heterogeneity in banking networks. We show that the presence of heterogeneous leverages drastically changes the systemic effects of defaults and the nature of the contagion in interbank markets. Using financial leverage data from the US banking system, through simulations, we analyze the systemic significance of different types of borrowers, the evolution of the network, the consequences of interbank market size and the impact of market segmentation. Our study is related to the recent Basel III regulations on systemic risk and the treatment of the Global Systemically Important Banks (GSIBs). We also assess the extent to which the recent capital surcharges on GSIBs may curb financial fragility. We show the effectiveness of surcharge policy for the most-levered banks vis-a-vis uniform capital injection.

  10. Implementation of an integrated network of various ISR-systems

    NASA Astrophysics Data System (ADS)

    Böker, D.

    2009-05-01

    Experiments were carried out at naval base Eckernförde, Germany, bringing together several projects concerning Defense Against Terrorism (DAT) and the net-centric battlespace. An integrated network of various Intelligence, Surveillance and Reconnaissance (ISR) systems was realized to evaluate the benefit of net-centric operations, i. e. in DAT focusing on force protection. ISR systems of the German Army, Air force, and Navy as well as a number of not yet operational systems were integrated in a joint network. Information relationships, data models, collaborative system functions and services were defined for as much as 27 systems from 20 companies. The NATO ISR Interoperability Architecture (NIIA) as the corner stone of technical standards for interoperable ISR products like images and motion imagery was used to the extent possible. Services and systems adopted by the multinational project MAJIIC were the starting point to develop appropriate collaboration tools and mechanisms.

  11. Chemical reaction network approaches to Biochemical Systems Theory.

    PubMed

    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.

  12. The Deep Space Network information system in the year 2000

    NASA Technical Reports Server (NTRS)

    Markley, R. W.; Beswick, C. A.

    1992-01-01

    The Deep Space Network (DSN), the largest, most sensitive scientific communications and radio navigation network in the world, is considered. Focus is made on the telemetry processing, monitor and control, and ground data transport architectures of the DSN ground information system envisioned for the year 2000. The telemetry architecture will be unified from the front-end area to the end user. It will provide highly automated monitor and control of the DSN, automated configuration of support activities, and a vastly improved human interface. Automated decision support systems will be in place for DSN resource management, performance analysis, fault diagnosis, and contingency management.

  13. Synchronization of an uncertain chaotic system via recurrent neural networks

    NASA Astrophysics Data System (ADS)

    Tan, Wen; Wang, Yao-Nan

    2005-01-01

    Incorporating distributed recurrent networks with high-order connections between neurons, the identification and synchronization problem of an unknown chaotic system in the presence of unmodelled dynamics is investigated. Based on the Lyapunov stability theory, the weights learning algorithm for the recurrent high-order neural network model is presented. Also, analytical results concerning the stability properties of the scheme are obtained. Then adaptive control law for eliminating synchronization error of uncertain chaotic plant is developed via Lyapunov methodology. The proposed scheme is applied to model and synchronize an unknown Rossler system.

  14. The Network Configuration of an Object Relational Database Management System

    NASA Technical Reports Server (NTRS)

    Diaz, Philip; Harris, W. C.

    2000-01-01

    The networking and implementation of the Oracle Database Management System (ODBMS) requires developers to have knowledge of the UNIX operating system as well as all the features of the Oracle Server. The server is an object relational database management system (DBMS). By using distributed processing, processes are split up between the database server and client application programs. The DBMS handles all the responsibilities of the server. The workstations running the database application concentrate on the interpretation and display of data.

  15. Enterprise network intrusion detection and prevention system (ENIDPS)

    NASA Astrophysics Data System (ADS)

    Akujuobi, C. M.; Ampah, N. K.

    2007-04-01

    Securing enterprise networks comes under two broad topics: Intrusion Detection Systems (IDS) and Intrusion Prevention Systems (IPS). The right combination of selected algorithms/techniques under both topics produces better security for a given network. This approach leads to using layers of physical, administrative, electronic, and encrypted systems to protect valuable resources. So far, there is no algorithm, which guarantees absolute protection for a given network from intruders. Intrusion Prevention Systems like IPSec, Firewall, Sender ID, Domain Keys Identified Mail (DKIM) etc. do not guarantee absolute security just like existing Intrusion Detection Systems. Our approach focuses on developing an IDS, which will detect all intruders that bypass the IPS and at the same time will be used in updating the IPS, since the IPS fail to prevent some intruders from entering a given network. The new IDS will employ both signature-based detection and anomaly detection as its analysis strategy. It should therefore be able to detect known and unknown intruders or attacks and further isolate those sources of attack within the network. Both real-time and off-line IDS predictions will be applied under the analysis and response stages. The basic IDS architecture will involve both centralized and distributed/heterogeneous architecture to ensure effective detection. Pro-active responses and corrective responses will be employed. The new security system, which will be made up of both IDS and IPS, should be less expensive to implement compared to existing ones. Finally, limitations of existing security systems have to be eliminated with the introduction of the new security system.

  16. Applications of neural networks in chemical engineering: Hybrid systems

    SciTech Connect

    Ferrada, J.J.; Osborne-Lee, I.W. ); Grizzaffi, P.A. )

    1990-01-01

    Expert systems are known to be useful in capturing expertise and applying knowledge to chemical engineering problems such as diagnosis, process control, process simulation, and process advisory. However, expert system applications are traditionally limited to knowledge domains that are heuristic and involve only simple mathematics. Neural networks, on the other hand, represent an emerging technology capable of rapid recognition of patterned behavior without regard to mathematical complexity. Although useful in problem identification, neural networks are not very efficient in providing in-depth solutions and typically do not promote full understanding of the problem or the reasoning behind its solutions. Hence, applications of neural networks have certain limitations. This paper explores the potential for expanding the scope of chemical engineering areas where neural networks might be utilized by incorporating expert systems and neural networks into the same application, a process called hybridization. In addition, hybrid applications are compared with those using more traditional approaches, the results of the different applications are analyzed, and the feasibility of converting the preliminary prototypes described herein into useful final products is evaluated. 12 refs., 8 figs.

  17. Information and entropy in neural networks and interacting systems

    NASA Astrophysics Data System (ADS)

    Shafee, Fariel

    In this dissertation we present a study of certain characteristics of interacting systems that are related to information. The first is periodicity, correlation and other information-related properties of neural networks of integrate-and-fire type. We also form quasiclassical and quantum generalizations of such networks and identify the similarities and differences with the classical prototype. We indicate why entropy may be an important concept for a neural network and why a generalization of the definition of entropy may be required. Like neural networks, large ensembles of similar units that interact also need a generalization of classical information-theoretic concepts. We extend the concept of Shannon entropy in a novel way, which may be relevant when we have such interacting systems, and show how it differs from Shannon entropy and other generalizations, such as Tsallis entropy. We indicate how classical stochasticity may arise in interactions with an entangled environment in a quantum system in terms of Shannon's and generalized entropies and identify the differences. Such differences are also indicated in the use of certain prior probability distributions to fit data as per Bayesian rules. We also suggest possible quantum versions of pattern recognition, which is the principal goal of information processing in most neural networks.

  18. Reliability Modeling of Microelectromechanical Systems Using Neural Networks

    NASA Technical Reports Server (NTRS)

    Perera. J. Sebastian

    2000-01-01

    Microelectromechanical systems (MEMS) are a broad and rapidly expanding field that is currently receiving a great deal of attention because of the potential to significantly improve the ability to sense, analyze, and control a variety of processes, such as heating and ventilation systems, automobiles, medicine, aeronautical flight, military surveillance, weather forecasting, and space exploration. MEMS are very small and are a blend of electrical and mechanical components, with electrical and mechanical systems on one chip. This research establishes reliability estimation and prediction for MEMS devices at the conceptual design phase using neural networks. At the conceptual design phase, before devices are built and tested, traditional methods of quantifying reliability are inadequate because the device is not in existence and cannot be tested to establish the reliability distributions. A novel approach using neural networks is created to predict the overall reliability of a MEMS device based on its components and each component's attributes. The methodology begins with collecting attribute data (fabrication process, physical specifications, operating environment, property characteristics, packaging, etc.) and reliability data for many types of microengines. The data are partitioned into training data (the majority) and validation data (the remainder). A neural network is applied to the training data (both attribute and reliability); the attributes become the system inputs and reliability data (cycles to failure), the system output. After the neural network is trained with sufficient data. the validation data are used to verify the neural networks provided accurate reliability estimates. Now, the reliability of a new proposed MEMS device can be estimated by using the appropriate trained neural networks developed in this work.

  19. A Study of the Effects of Fieldbus Network Induced Delays on Control Systems

    ERIC Educational Resources Information Center

    Mainoo, Joseph

    2012-01-01

    Fieldbus networks are all-digital, two-way, multi-drop communication systems that are used to connect field devices such as sensors and actuators, and controllers. These fieldbus network systems are also called networked control systems (NCS). Although, there are different varieties of fieldbus networks such as Foundation Field Bus, DeviceNet, and…

  20. Systemic Risk Analysis on Reconstructed Economic and Financial Networks

    NASA Astrophysics Data System (ADS)

    Cimini, Giulio; Squartini, Tiziano; Garlaschelli, Diego; Gabrielli, Andrea

    2015-10-01

    We address a fundamental problem that is systematically encountered when modeling real-world complex systems of societal relevance: the limitedness of the information available. In the case of economic and financial networks, privacy issues severely limit the information that can be accessed and, as a consequence, the possibility of correctly estimating the resilience of these systems to events such as financial shocks, crises and cascade failures. Here we present an innovative method to reconstruct the structure of such partially-accessible systems, based on the knowledge of intrinsic node-specific properties and of the number of connections of only a limited subset of nodes. This information is used to calibrate an inference procedure based on fundamental concepts derived from statistical physics, which allows to generate ensembles of directed weighted networks intended to represent the real system—so that the real network properties can be estimated as their average values within the ensemble. We test the method both on synthetic and empirical networks, focusing on the properties that are commonly used to measure systemic risk. Indeed, the method shows a remarkable robustness with respect to the limitedness of the information available, thus representing a valuable tool for gaining insights on privacy-protected economic and financial systems.

  1. Debugging expert systems using a dynamically created hypertext network

    NASA Technical Reports Server (NTRS)

    Boyle, Craig D. B.; Schuette, John F.

    1991-01-01

    The labor intensive nature of expert system writing and debugging motivated this study. The hypothesis is that a hypertext based debugging tool is easier and faster than one traditional tool, the graphical execution trace. HESDE (Hypertext Expert System Debugging Environment) uses Hypertext nodes and links to represent the objects and their relationships created during the execution of a rule based expert system. HESDE operates transparently on top of the CLIPS (C Language Integrated Production System) rule based system environment and is used during the knowledge base debugging process. During the execution process HESDE builds an execution trace. Use of facts, rules, and their values are automatically stored in a Hypertext network for each execution cycle. After the execution process, the knowledge engineer may access the Hypertext network and browse the network created. The network may be viewed in terms of rules, facts, and values. An experiment was conducted to compare HESDE with a graphical debugging environment. Subjects were given representative tasks. For speed and accuracy, in eight of the eleven tasks given to subjects, HESDE was significantly better.

  2. Systemic Risk Analysis on Reconstructed Economic and Financial Networks

    PubMed Central

    Cimini, Giulio; Squartini, Tiziano; Garlaschelli, Diego; Gabrielli, Andrea

    2015-01-01

    We address a fundamental problem that is systematically encountered when modeling real-world complex systems of societal relevance: the limitedness of the information available. In the case of economic and financial networks, privacy issues severely limit the information that can be accessed and, as a consequence, the possibility of correctly estimating the resilience of these systems to events such as financial shocks, crises and cascade failures. Here we present an innovative method to reconstruct the structure of such partially-accessible systems, based on the knowledge of intrinsic node-specific properties and of the number of connections of only a limited subset of nodes. This information is used to calibrate an inference procedure based on fundamental concepts derived from statistical physics, which allows to generate ensembles of directed weighted networks intended to represent the real system—so that the real network properties can be estimated as their average values within the ensemble. We test the method both on synthetic and empirical networks, focusing on the properties that are commonly used to measure systemic risk. Indeed, the method shows a remarkable robustness with respect to the limitedness of the information available, thus representing a valuable tool for gaining insights on privacy-protected economic and financial systems. PMID:26507849

  3. Network adaptable information systems for safeguard applications

    SciTech Connect

    Rodriguez, C.; Burczyk, L.; Chare, P.; Wagner, H.

    1996-09-01

    While containment and surveillance systems designed for nuclear safeguards have greatly improved through advances in computer, sensor, and microprocessor technologies, the authors recognize the need to continue the advancement of these systems to provide more standardized solutions for safeguards applications of the future. The benefits to be gained from the use of standardized technologies are becoming evident as safeguard activities are increasing world-wide while funding of these activities is becoming more limited. The EURATOM Safeguards Directorate and Los Alamos National Laboratory are developing and testing advanced monitoring technologies coupled with the most efficient solutions for the safeguards applications of the future.

  4. Sensor network based vehicle classification and license plate identification system

    SciTech Connect

    Frigo, Janette Rose; Brennan, Sean M; Rosten, Edward J; Raby, Eric Y; Kulathumani, Vinod K

    2009-01-01

    Typically, for energy efficiency and scalability purposes, sensor networks have been used in the context of environmental and traffic monitoring applications in which operations at the sensor level are not computationally intensive. But increasingly, sensor network applications require data and compute intensive sensors such video cameras and microphones. In this paper, we describe the design and implementation of two such systems: a vehicle classifier based on acoustic signals and a license plate identification system using a camera. The systems are implemented in an energy-efficient manner to the extent possible using commercially available hardware, the Mica motes and the Stargate platform. Our experience in designing these systems leads us to consider an alternate more flexible, modular, low-power mote architecture that uses a combination of FPGAs, specialized embedded processing units and sensor data acquisition systems.

  5. Program Support Communications Network (PSCN) facsimile system directory

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This directory provides a system description, a station listing, and operating procedures for the Program Support Communications Network (PSCN) NASA Facsimile System. The NASA Facsimile System is a convenient and efficient means of spanning the distance, time, and cost of transmitting documents from one person to another. In the spectrum of communication techniques, facsimile bridges the gap between mail and data transmission. Facsimile can transmit in a matter of minutes or seconds what would take a day or more by mail delivery. The NASA Facsimile System is composed of several makes and models of facsimile machines. The system also supports the 3M FaxXchange network controllers located at Marshall Space Flight Center (MSFC).

  6. Performance limitations for networked control systems with plant uncertainty

    NASA Astrophysics Data System (ADS)

    Chi, Ming; Guan, Zhi-Hong; Cheng, Xin-Ming; Yuan, Fu-Shun

    2016-04-01

    There has recently been significant interest in performance study for networked control systems with communication constraints. But the existing work mainly assumes that the plant has an exact model. The goal of this paper is to investigate the optimal tracking performance for networked control system in the presence of plant uncertainty. The plant under consideration is assumed to be non-minimum phase and unstable, while the two-parameter controller is employed and the integral square criterion is adopted to measure the tracking error. And we formulate the uncertainty by utilising stochastic embedding. The explicit expression of the tracking performance has been obtained. The results show that the network communication noise and the model uncertainty, as well as the unstable poles and non-minimum phase zeros, can worsen the tracking performance.

  7. Quantifying sudden changes in dynamical systems using symbolic networks

    NASA Astrophysics Data System (ADS)

    Masoller, Cristina; Hong, Yanhua; Ayad, Sarah; Gustave, Francois; Barland, Stephane; Pons, Antonio J.; Gómez, Sergio; Arenas, Alex

    2015-02-01

    We characterize the evolution of a dynamical system by combining two well-known complex systems’ tools, namely, symbolic ordinal analysis and networks. From the ordinal representation of a time series we construct a network in which every node weight represents the probability of an ordinal pattern (OP) to appear in the symbolic sequence and each edge's weight represents the probability of transitions between two consecutive OPs. Several network-based diagnostics are then proposed to characterize the dynamics of different systems: logistic, tent, and circle maps. We show that these diagnostics are able to capture changes produced in the dynamics as a control parameter is varied. We also apply our new measures to empirical data from semiconductor lasers and show that they are able to anticipate the polarization switchings, thus providing early warning signals of abrupt transitions.

  8. System Integration and Network Planning in the Academic Health Center

    PubMed Central

    Testa, Marcia A.; Spackman, Thomas J.

    1985-01-01

    The transfer of information within the academic health center is complicated by the complex nature of the institution's multi-dimensional role. The diverse functions of patient care, administration, education and research result in a complex web of information exchange which requires an integrated approach to system management. System integration involves a thorough assessment of “end user” needs in terms of hardware and software as well as specification of the communications network architecture. The network will consist of a series of end user nodes which capture, process, archive and display information. This paper will consider some requirements of these nodes, also called intelligent workstations, relating to their management and integration into a total health care network.

  9. A cognitive fault diagnosis system for distributed sensor networks.

    PubMed

    Alippi, Cesare; Ntalampiras, Stavros; Roveri, Manuel

    2013-08-01

    This paper introduces a novel cognitive fault diagnosis system (FDS) for distributed sensor networks that takes advantage of spatial and temporal relationships among sensors. The proposed FDS relies on a suitable functional graph representation of the network and a two-layer hierarchical architecture designed to promptly detect and isolate faults. The lower processing layer exploits a novel change detection test (CDT) based on hidden Markov models (HMMs) configured to detect variations in the relationships between couples of sensors. HMMs work in the parameter space of linear time-invariant dynamic systems, approximating, over time, the relationship between two sensors; changes in the approximating model are detected by inspecting the HMM likelihood. Information provided by the CDT layer is then passed to the cognitive one, which, by exploiting the graph representation of the network, aggregates information to discriminate among faults, changes in the environment, and false positives induced by the model bias of the HMMs.

  10. Performance evaluation of a holographic optical neural network system

    NASA Astrophysics Data System (ADS)

    Lu, Thomas T.; Kostrzewski, Andrew A.; Chou, Hung; Wu, Shudong; Lin, Freddie S.

    1993-02-01

    One of the most outstanding properties of artificial neural networks is their capability for massive interconnection and parallel processing. Recently, specialized electronic neural network processors and VLSI neural chips have been introduced to the commercial market. The number of parallel channels they can handle is limited because of the limited parallel interconnections number with one-dimensional (1-D) electronic wires. High resolution pattern recognition problems may require a large number of neurons for parallel processing of the image. The holographic optical neural network (HONN) based on high resolution volume holographic materials is capable of providing 3-D massive parallel interconnection of tens of thousand of neurons. A HONN with 3600 neurons, contained in a portable briefcase, has been developed. Rotation-shift-scale invariant pattern recognition operations have been demonstrated with this system. System parameters, such as signal-to-noise ratio, dynamic range, and processing speed, will be discussed.

  11. Dissipative rendering and neural network control system design

    NASA Technical Reports Server (NTRS)

    Gonzalez, Oscar R.

    1995-01-01

    Model-based control system designs are limited by the accuracy of the models of the plant, plant uncertainty, and exogenous signals. Although better models can be obtained with system identification, the models and control designs still have limitations. One approach to reduce the dependency on particular models is to design a set of compensators that will guarantee robust stability to a set of plants. Optimization over the compensator parameters can then be used to get the desired performance. Conservativeness of this approach can be reduced by integrating fundamental properties of the plant models. This is the approach of dissipative control design. Dissipative control designs are based on several variations of the Passivity Theorem, which have been proven for nonlinear/linear and continuous-time/discrete-time systems. These theorems depend not on a specific model of a plant, but on its general dissipative properties. Dissipative control design has found wide applicability in flexible space structures and robotic systems that can be configured to be dissipative. Currently, there is ongoing research to improve the performance of dissipative control designs. For aircraft systems that are not dissipative active control may be used to make them dissipative and then a dissipative control design technique can be used. It is also possible that rendering a system dissipative and dissipative control design may be combined into one step. Furthermore, the transformation of a non-dissipative system to dissipative can be done robustly. One sequential design procedure for finite dimensional linear time-invariant systems has been developed. For nonlinear plants that cannot be controlled adequately with a single linear controller, model-based techniques have additional problems. Nonlinear system identification is still a research topic. Lacking analytical models for model-based design, artificial neural network algorithms have recently received considerable attention. Using

  12. Real Time Network Monitoring and Reporting System

    ERIC Educational Resources Information Center

    Massengale, Ricky L., Sr.

    2009-01-01

    With the ability of modern system developers to develop intelligent programs that allows machines to learn, modify and evolve themselves, current trends of reactionary methods to detect and eradicate malicious software code from infected machines is proving to be too costly. Addressing malicious software after an attack is the current methodology…

  13. Pathways, Networks, and Systems: Theory and Experiments

    SciTech Connect

    Joseph H. Nadeau; John D. Lambris

    2004-10-30

    The international conference provided a unique opportunity for theoreticians and experimenters to exchange ideas, strategies, problems, challenges, language and opportunities in both formal and informal settings. This dialog is an important step towards developing a deep and effective integration of theory and experiments in studies of systems biology in humans and model organisms.

  14. A system of recurrent neural networks for modularising, parameterising and dynamic analysis of cell signalling networks.

    PubMed

    Samarasinghe, S; Ling, H

    2017-02-04

    In this paper, we show how to extend our previously proposed novel continuous time Recurrent Neural Networks (RNN) approach that retains the advantage of continuous dynamics offered by Ordinary Differential Equations (ODE) while enabling parameter estimation through adaptation, to larger signalling networks using a modular approach. Specifically, the signalling network is decomposed into several sub-models based on important temporal events in the network. Each sub-model is represented by the proposed RNN and trained using data generated from the corresponding ODE model. Trained sub-models are assembled into a whole system RNN which is then subjected to systems dynamics and sensitivity analyses. The concept is illustrated by application to G1/S transition in cell cycle using Iwamoto et al. (2008) ODE model. We decomposed the G1/S network into 3 sub-models: (i) E2F transcription factor release; (ii) E2F and CycE positive feedback loop for elevating cyclin levels; and (iii) E2F and CycA negative feedback to degrade E2F. The trained sub-models accurately represented system dynamics and parameters were in good agreement with the ODE model. The whole system RNN however revealed couple of parameters contributing to compounding errors due to feedback and required refinement to sub-model 2. These related to the reversible reaction between CycE/CDK2 and p27, its inhibitor. The revised whole system RNN model very accurately matched dynamics of the ODE system. Local sensitivity analysis of the whole system model further revealed the most dominant influence of the above two parameters in perturbing G1/S transition, giving support to a recent hypothesis that the release of inhibitor p27 from Cyc/CDK complex triggers cell cycle stage transition. To make the model useful in a practical setting, we modified each RNN sub-model with a time relay switch to facilitate larger interval input data (≈20min) (original model used data for 30s or less) and retrained them that produced

  15. Design and Performance Analysis of Incremental Networked Predictive Control Systems.

    PubMed

    Pang, Zhong-Hua; Liu, Guo-Ping; Zhou, Donghua

    2016-06-01

    This paper is concerned with the design and performance analysis of networked control systems with network-induced delay, packet disorder, and packet dropout. Based on the incremental form of the plant input-output model and an incremental error feedback control strategy, an incremental networked predictive control (INPC) scheme is proposed to actively compensate for the round-trip time delay resulting from the above communication constraints. The output tracking performance and closed-loop stability of the resulting INPC system are considered for two cases: 1) plant-model match case and 2) plant-model mismatch case. For the former case, the INPC system can achieve the same output tracking performance and closed-loop stability as those of the corresponding local control system. For the latter case, a sufficient condition for the stability of the closed-loop INPC system is derived using the switched system theory. Furthermore, for both cases, the INPC system can achieve a zero steady-state output tracking error for step commands. Finally, both numerical simulations and practical experiments on an Internet-based servo motor system illustrate the effectiveness of the proposed method.

  16. The Accounting Network: How Financial Institutions React to Systemic Crisis

    PubMed Central

    Puliga, Michelangelo; Flori, Andrea; Pappalardo, Giuseppe; Chessa, Alessandro; Pammolli, Fabio

    2016-01-01

    The role of Network Theory in the study of the financial crisis has been widely spotted in the latest years. It has been shown how the network topology and the dynamics running on top of it can trigger the outbreak of large systemic crisis. Following this methodological perspective we introduce here the Accounting Network, i.e. the network we can extract through vector similarities techniques from companies’ financial statements. We build the Accounting Network on a large database of worldwide banks in the period 2001–2013, covering the onset of the global financial crisis of mid-2007. After a careful data cleaning, we apply a quality check in the construction of the network, introducing a parameter (the Quality Ratio) capable of trading off the size of the sample (coverage) and the representativeness of the financial statements (accuracy). We compute several basic network statistics and check, with the Louvain community detection algorithm, for emerging communities of banks. Remarkably enough sensible regional aggregations show up with the Japanese and the US clusters dominating the community structure, although the presence of a geographically mixed community points to a gradual convergence of banks into similar supranational practices. Finally, a Principal Component Analysis procedure reveals the main economic components that influence communities’ heterogeneity. Even using the most basic vector similarity hypotheses on the composition of the financial statements, the signature of the financial crisis clearly arises across the years around 2008. We finally discuss how the Accounting Networks can be improved to reflect the best practices in the financial statement analysis. PMID:27736865

  17. The Accounting Network: How Financial Institutions React to Systemic Crisis.

    PubMed

    Puliga, Michelangelo; Flori, Andrea; Pappalardo, Giuseppe; Chessa, Alessandro; Pammolli, Fabio

    2016-01-01

    The role of Network Theory in the study of the financial crisis has been widely spotted in the latest years. It has been shown how the network topology and the dynamics running on top of it can trigger the outbreak of large systemic crisis. Following this methodological perspective we introduce here the Accounting Network, i.e. the network we can extract through vector similarities techniques from companies' financial statements. We build the Accounting Network on a large database of worldwide banks in the period 2001-2013, covering the onset of the global financial crisis of mid-2007. After a careful data cleaning, we apply a quality check in the construction of the network, introducing a parameter (the Quality Ratio) capable of trading off the size of the sample (coverage) and the representativeness of the financial statements (accuracy). We compute several basic network statistics and check, with the Louvain community detection algorithm, for emerging communities of banks. Remarkably enough sensible regional aggregations show up with the Japanese and the US clusters dominating the community structure, although the presence of a geographically mixed community points to a gradual convergence of banks into similar supranational practices. Finally, a Principal Component Analysis procedure reveals the main economic components that influence communities' heterogeneity. Even using the most basic vector similarity hypotheses on the composition of the financial statements, the signature of the financial crisis clearly arises across the years around 2008. We finally discuss how the Accounting Networks can be improved to reflect the best practices in the financial statement analysis.

  18. CI-KNOW: Cyberinfrastructure Knowledge Networks on the Web. A Social Network Enabled Recommender System for Locating Resources in Cyberinfrastructures

    NASA Astrophysics Data System (ADS)

    Green, H. D.; Contractor, N. S.; Yao, Y.

    2006-12-01

    A knowledge network is a multi-dimensional network created from the interactions and interconnections among the scientists, documents, data, analytic tools, and interactive collaboration spaces (like forums and wikis) associated with a collaborative environment. CI-KNOW is a suite of software tools that leverages automated data collection, social network theories, analysis techniques and algorithms to infer an individual's interests and expertise based on their interactions and activities within a knowledge network. The CI-KNOW recommender system mines the knowledge network associated with a scientific community's use of cyberinfrastructure tools and uses relational metadata to record connections among entities in the knowledge network. Recent developments in social network theories and methods provide the backbone for a modular system that creates recommendations from relational metadata. A network navigation portlet allows users to locate colleagues, documents, data or analytic tools in the knowledge network and to explore their networks through a visual, step-wise process. An internal auditing portlet offers administrators diagnostics to assess the growth and health of the entire knowledge network. The first instantiation of the prototype CI-KNOW system is part of the Environmental Cyberinfrastructure Demonstration project at the National Center for Supercomputing Applications, which supports the activities of hydrologic and environmental science communities (CLEANER and CUAHSI) under the umbrella of the WATERS network environmental observatory planning activities (http://cleaner.ncsa.uiuc.edu). This poster summarizes the key aspects of the CI-KNOW system, highlighting the key inputs, calculation mechanisms, and output modalities.

  19. Dynamical system modeling via signal reduction and neural network simulation

    SciTech Connect

    Paez, T.L.; Hunter, N.F.

    1997-11-01

    Many dynamical systems tested in the field and the laboratory display significant nonlinear behavior. Accurate characterization of such systems requires modeling in a nonlinear framework. One construct forming a basis for nonlinear modeling is that of the artificial neural network (ANN). However, when system behavior is complex, the amount of data required to perform training can become unreasonable. The authors reduce the complexity of information present in system response measurements using decomposition via canonical variate analysis. They describe a method for decomposing system responses, then modeling the components with ANNs. A numerical example is presented, along with conclusions and recommendations.

  20. Supervisory Control of Networked Control Systems

    DTIC Science & Technology

    2006-01-15

    consisting of 3 Koala robots [Lem06b]. The robots are controlled by MICA2 wireless processor modules. The robots communicate over the MICA2’s...preliminary documentation of a wireless autonomous robotic testbed. The system consists of 3 Koala (K-team Inc.) robots that are controlled by the MICA2...by this project. MICA-KoalaBot Hardware: The Koala robot is an autonomous wheeled vehicle that has 16 infrared (IR) proximity sensors around its

  1. UWIN: a universal wireless infrared network system

    NASA Astrophysics Data System (ADS)

    Medved, David B.; Halpern, Ron

    1995-09-01

    Wireless data communications are currently being implemented by the complementary technologies of RF and IR. The RF options provide larger area coverage than wireless optical communications but are limited in full bandwidth throughput to about 5 Mbps whereas infrared systems using IR-LED have achieved data rates up to 125 Mbps which makes them suitable for use in FDDI, Fast Ethernet and ATM wireless connectivity as well as Token Ring, Ethernet and PABX (voice).

  2. System and Network Security Acronyms and Abbreviations

    DTIC Science & Technology

    2009-09-01

    Advanced Encryption Standard-Cipher Block Chaining AES-CTR Advanced Encryption Standard-Counter Mode AFH adaptive frequency hopping A-GPS assisted global...CIRC computer incident response capability CIRC computer incident response center CIRDB CERIAS Incident Response Database CIRT computer incident...Agency dBm decibels referenced to one milliwatt DBMS database management system DC domain controller DCE Distributed Computing Environment DCOM

  3. 77 FR 5864 - BluePoint Linux Software Corp., China Bottles Inc., Long-e International, Inc., and Nano...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-06

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION BluePoint Linux Software Corp., China Bottles Inc., Long-e International, Inc., and Nano... securities of BluePoint Linux Software Corp. because it has not filed any periodic reports since the...

  4. Networked vision system using a Prolog controller

    NASA Astrophysics Data System (ADS)

    Batchelor, B. G.; Caton, S. J.; Chatburn, L. T.; Crowther, R. A.; Miller, J. W. V.

    2005-11-01

    Prolog offers a very different style of programming compared to conventional languages; it can define object properties and abstract relationships in a way that Java, C, C++, etc. find awkward. In an accompanying paper, the authors describe how a distributed web-based vision systems can be built using elements that may even be located on different continents. One particular system of this general type is described here. The top-level controller is a Prolog program, which operates one, or more, image processing engines. This type of function is natural to Prolog, since it is able to reason logically using symbolic (non-numeric) data. Although Prolog is not suitable for programming image processing functions directly, it is ideal for analysing the results derived by an image processor. This article describes the implementation of two systems, in which a Prolog program controls several image processing engines, a simple robot, a pneumatic pick-and-place arm), LED illumination modules and a various mains-powered devices.

  5. Bayesian networks as a tool for epidemiological systems analysis

    NASA Astrophysics Data System (ADS)

    Lewis, F. I.

    2012-11-01

    Bayesian network analysis is a form of probabilistic modeling which derives from empirical data a directed acyclic graph (DAG) describing the dependency structure between random variables. Bayesian networks are increasingly finding application in areas such as computational and systems biology, and more recently in epidemiological analyses. The key distinction between standard empirical modeling approaches, such as generalised linear modeling, and Bayesian network analyses is that the latter attempts not only to identify statistically associated variables, but to additionally, and empirically, separate these into those directly and indirectly dependent with one or more outcome variables. Such discrimination is vastly more ambitious but has the potential to reveal far more about key features of complex disease systems. Applying Bayesian network modeling to biological and medical data has considerable computational demands, combined with the need to ensure robust model selection given the vast model space of possible DAGs. These challenges require the use of approximation techniques, such as the Laplace approximation, Markov chain Monte Carlo simulation and parametric bootstrapping, along with computational parallelization. A case study in structure discovery - identification of an optimal DAG for given data - is presented which uses additive Bayesian networks to explore veterinary disease data of industrial and medical relevance.

  6. Multimedia and multiservice systems for home, office, and industrial networks

    NASA Astrophysics Data System (ADS)

    Junger, Stephan; Tschekalinskij, Wladimir; Weber, Norbert

    2004-04-01

    The optical transmission of signals has several significant advantages like high transmission capacity, immunity from electromagnetic interference, and thin and low weight cables. Optical networks have a high potential for applications in buildings, but they will be widely used only if component and installation costs are reduced. One promising candidate especially for home networks is polymer optical fiber (POF) due to the low cost of the fiber and its installation, as well as significantly lower costs of all active and passive components compared to networks based on silica fibers. The present paper describes the properties of polymer optical fibers (POF), active and passive components developed in our institute for networks based on POF as well as different transmission experiments. The applications of these transmission systems for multimedia and multiservice networks are the distribution of video signals, the transmission of TV signals with carrier frequencies beyond the 3-dB bandwidth of POF, and a multimedia system for the transmission of video, audio, and data signals using wavelength division multiplexing (WDM).

  7. Inverse Optimal Pinning Control for Complex Networks of Chaotic Systems

    NASA Astrophysics Data System (ADS)

    Sanchez, Edgar N.; Rodriguez, David I.

    In this paper, a control strategy based on the inverse optimal control approach is applied for pinning weighted complex networks with chaotic systems at their nodes; additionally, a cost functional is minimized. This control strategy does not require to have the same coupling strength for all node connections.

  8. Phosphorimager and PD densitometer imaging system network. Technical report

    SciTech Connect

    1995-05-01

    This document discusses the research projects undertaken as a result of the availability of the PhosphorImager and PD Densitometer Imaging System Network, at the University of Georgia`s Complex Carbohydrate Research Center. The benefit gained from the equipment is described for each project.

  9. Information Systems and Networks for Technology Transfer. Final Report.

    ERIC Educational Resources Information Center

    Page, John; Szentivanyi, Tibor

    Results of a survey of the information resources available in industrialized countries which might be used in a United Nations technology transfer program for developing countries are presented. Information systems and networks, organized information collections of a scientific and technical character, and the machinery used to disseminate this…

  10. Systems Biology in the Context of Big Data and Networks

    PubMed Central

    Altaf-Ul-Amin, Md.; Afendi, Farit Mochamad; Kiboi, Samuel Kuria; Kanaya, Shigehiko

    2014-01-01

    Science is going through two rapidly changing phenomena: one is the increasing capabilities of the computers and software tools from terabytes to petabytes and beyond, and the other is the advancement in high-throughput molecular biology producing piles of data related to genomes, transcriptomes, proteomes, metabolomes, interactomes, and so on. Biology has become a data intensive science and as a consequence biology and computer science have become complementary to each other bridged by other branches of science such as statistics, mathematics, physics, and chemistry. The combination of versatile knowledge has caused the advent of big-data biology, network biology, and other new branches of biology. Network biology for instance facilitates the system-level understanding of the cell or cellular components and subprocesses. It is often also referred to as systems biology. The purpose of this field is to understand organisms or cells as a whole at various levels of functions and mechanisms. Systems biology is now facing the challenges of analyzing big molecular biological data and huge biological networks. This review gives an overview of the progress in big-data biology, and data handling and also introduces some applications of networks and multivariate analysis in systems biology. PMID:24982882

  11. Role of Communication Networks in Behavioral Systems Analysis

    ERIC Educational Resources Information Center

    Houmanfar, Ramona; Rodrigues, Nischal Joseph; Smith, Gregory S.

    2009-01-01

    This article provides an overview of communication networks and the role of verbal behavior in behavioral systems analysis. Our discussion highlights styles of leadership in the design and implementation of effective organizational contingencies that affect ways by which coordinated work practices are managed. We draw upon literature pertaining to…

  12. Systems biology in the context of big data and networks.

    PubMed

    Altaf-Ul-Amin, Md; Afendi, Farit Mochamad; Kiboi, Samuel Kuria; Kanaya, Shigehiko

    2014-01-01

    Science is going through two rapidly changing phenomena: one is the increasing capabilities of the computers and software tools from terabytes to petabytes and beyond, and the other is the advancement in high-throughput molecular biology producing piles of data related to genomes, transcriptomes, proteomes, metabolomes, interactomes, and so on. Biology has become a data intensive science and as a consequence biology and computer science have become complementary to each other bridged by other branches of science such as statistics, mathematics, physics, and chemistry. The combination of versatile knowledge has caused the advent of big-data biology, network biology, and other new branches of biology. Network biology for instance facilitates the system-level understanding of the cell or cellular components and subprocesses. It is often also referred to as systems biology. The purpose of this field is to understand organisms or cells as a whole at various levels of functions and mechanisms. Systems biology is now facing the challenges of analyzing big molecular biological data and huge biological networks. This review gives an overview of the progress in big-data biology, and data handling and also introduces some applications of networks and multivariate analysis in systems biology.

  13. Complexity, Robustness, and Multistability in Network Systems with Switching Topologies: A Hierarchical Hybrid Control Approach

    DTIC Science & Technology

    2015-05-22

    AFRL-AFOSR-VA-TR-2015-0282 Complexity, Robustness, and Multistability in Network Systems with Switching Topologies A Hierarchical Hybrid Control ...concentrated on the development of a unified discontinuous dynamical framework for nonlinear network systems. In particular, control algorithms were... network systems, large-scale systems, adaptive control , discontinuous systems 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF

  14. Robust nonlinear variable selective control for networked systems

    NASA Astrophysics Data System (ADS)

    Rahmani, Behrooz

    2016-10-01

    This paper is concerned with the networked control of a class of uncertain nonlinear systems. In this way, Takagi-Sugeno (T-S) fuzzy modelling is used to extend the previously proposed variable selective control (VSC) methodology to nonlinear systems. This extension is based upon the decomposition of the nonlinear system to a set of fuzzy-blended locally linearised subsystems and further application of the VSC methodology to each subsystem. To increase the applicability of the T-S approach for uncertain nonlinear networked control systems, this study considers the asynchronous premise variables in the plant and the controller, and then introduces a robust stability analysis and control synthesis. The resulting optimal switching-fuzzy controller provides a minimum guaranteed cost on an H2 performance index. Simulation studies on three nonlinear benchmark problems demonstrate the effectiveness of the proposed method.

  15. On the Interplay between the Evolvability and Network Robustness in an Evolutionary Biological Network: A Systems Biology Approach

    PubMed Central

    Chen, Bor-Sen; Lin, Ying-Po

    2011-01-01

    In the evolutionary process, the random transmission and mutation of genes provide biological diversities for natural selection. In order to preserve functional phenotypes between generations, gene networks need to evolve robustly under the influence of random perturbations. Therefore, the robustness of the phenotype, in the evolutionary process, exerts a selection force on gene networks to keep network functions. However, gene networks need to adjust, by variations in genetic content, to generate phenotypes for new challenges in the network’s evolution, ie, the evolvability. Hence, there should be some interplay between the evolvability and network robustness in evolutionary gene networks. In this study, the interplay between the evolvability and network robustness of a gene network and a biochemical network is discussed from a nonlinear stochastic system point of view. It was found that if the genetic robustness plus environmental robustness is less than the network robustness, the phenotype of the biological network is robust in evolution. The tradeoff between the genetic robustness and environmental robustness in evolution is discussed from the stochastic stability robustness and sensitivity of the nonlinear stochastic biological network, which may be relevant to the statistical tradeoff between bias and variance, the so-called bias/variance dilemma. Further, the tradeoff could be considered as an antagonistic pleiotropic action of a gene network and discussed from the systems biology perspective. PMID:22084563

  16. Physical Modeling of Scaled Water Distribution System Networks.

    SciTech Connect

    O'Hern, Timothy J.; Hammond, Glenn Edward; Orear, Leslie ,; van Bloemen Waanders, Bart G.; Paul Molina; Ross Johnson

    2005-10-01

    Threats to water distribution systems include release of contaminants and Denial of Service (DoS) attacks. A better understanding, and validated computational models, of the flow in water distribution systems would enable determination of sensor placement in real water distribution networks, allow source identification, and guide mitigation/minimization efforts. Validation data are needed to evaluate numerical models of network operations. Some data can be acquired in real-world tests, but these are limited by 1) unknown demand, 2) lack of repeatability, 3) too many sources of uncertainty (demand, friction factors, etc.), and 4) expense. In addition, real-world tests have limited numbers of network access points. A scale-model water distribution system was fabricated, and validation data were acquired over a range of flow (demand) conditions. Standard operating variables included system layout, demand at various nodes in the system, and pressure drop across various pipe sections. In addition, the location of contaminant (salt or dye) introduction was varied. Measurements of pressure, flowrate, and concentration at a large number of points, and overall visualization of dye transport through the flow network were completed. Scale-up issues that that were incorporated in the experiment design include Reynolds number, pressure drop across nodes, and pipe friction and roughness. The scale was chosen to be 20:1, so the 10 inch main was modeled with a 0.5 inch pipe in the physical model. Controlled validation tracer tests were run to provide validation to flow and transport models, especially of the degree of mixing at pipe junctions. Results of the pipe mixing experiments showed large deviations from predicted behavior and these have a large impact on standard network operations models.3

  17. Performance analysis of Integrated Communication and Control System networks

    NASA Technical Reports Server (NTRS)

    Halevi, Y.; Ray, A.

    1990-01-01

    This paper presents statistical analysis of delays in Integrated Communication and Control System (ICCS) networks that are based on asynchronous time-division multiplexing. The models are obtained in closed form for analyzing control systems with randomly varying delays. The results of this research are applicable to ICCS design for complex dynamical processes like advanced aircraft and spacecraft, autonomous manufacturing plants, and chemical and processing plants.

  18. Model-based Compositional Design of Networked Control Systems

    DTIC Science & Technology

    2013-12-01

    26 2.3.4 Functional Mock-Up Interface( FMI ) and Functional Mock-Up Unit(FMU) 29 2.4 Dependability of Networked Control Systems...simulation. 2.3.4 Functional Mock-Up Interface ( FMI ) and Functional Mock-Up Unit (FMU) The growing trend in system design involves collaborative...Interface ( FMI ), first initiated by Daimler AG, is a tool indepen- dent standard introduced for the exchange of dynamic models and for co-simulation

  19. Use of Network Modeling Tools in the Nile System Design

    NASA Astrophysics Data System (ADS)

    Avery, Paul

    I discuss the relevance of network modeling tools to high energy physics experiments, particularly for understanding data flows and identifying possible bottlenecks during data analysis. The Nile collaboration is using these tools to model a fault-tolerant computing system distributed over geographically dispersed sites. I summarize Nile's evaluation of three commericial tools and our initial experience with OpNet Modeler from Mil3, Inc. These tools seem to offer an effective way of quantifying data movements from online acquisition to physics analysis, including how they are affected by storage mechanisms, distribution, and the characteristics of local and wide area networks.

  20. Systems biology and gene networks in neurodevelopmental and neurodegenerative disorders

    PubMed Central

    Parikshak, Neelroop N.; Gandal, Michael J.; Geschwind, Daniel H.

    2015-01-01

    Genetic and genomic approaches have implicated hundreds of genetic loci in neurodevelopmental disorders and neurodegeneration, but mechanistic understanding continues to lag behind the pace of gene discovery. Understanding the role of specific genetic variants in the brain involves dissecting a functional hierarchy that encompasses molecular pathways, diverse cell types, neural circuits and, ultimately, cognition and behaviour. With a focus on transcriptomics, this Review discusses how high-throughput molecular, integrative and network approaches inform disease biology by placing human genetics in a molecular systems and neurobiological context. We provide a framework for interpreting network biology studies and leveraging big genomics data sets in neurobiology. PMID:26149713

  1. Network-Oriented Radiation Monitoring System (NORMS)

    SciTech Connect

    Rahmat Aryaeinejad; David F. Spencer

    2007-10-01

    We have developed a multi-functional pocket radiation monitoring system capable of detecting and storing gamma ray and neutron data and then sending the data through a wireless connection to a remote central facility upon request. The device has programmable alarm trigger levels that can be modified for specific applications. The device could be used as a stand-alone device or in conjunction with an array to cover a small or large area. The data is stored with a date/time stamp. The device may be remotely configured. Data can be transferred and viewed on a PDA via direct connection or wirelessly. Functional/bench tests have been completed successfully. The device detects low-level neutron and gamma sources within a shielded container in a radiation field of 10 uR/hr above the ambient background level.

  2. Intelligent Wireless Sensor Networks for System Health Monitoring

    NASA Technical Reports Server (NTRS)

    Alena, Rick

    2011-01-01

    Wireless sensor networks (WSN) based on the IEEE 802.15.4 Personal Area Network (PAN) standard are finding increasing use in the home automation and emerging smart energy markets. The network and application layers, based on the ZigBee 2007 Standard, provide a convenient framework for component-based software that supports customer solutions from multiple vendors. WSNs provide the inherent fault tolerance required for aerospace applications. The Discovery and Systems Health Group at NASA Ames Research Center has been developing WSN technology for use aboard aircraft and spacecraft for System Health Monitoring of structures and life support systems using funding from the NASA Engineering and Safety Center and Exploration Technology Development and Demonstration Program. This technology provides key advantages for low-power, low-cost ancillary sensing systems particularly across pressure interfaces and in areas where it is difficult to run wires. Intelligence for sensor networks could be defined as the capability of forming dynamic sensor networks, allowing high-level application software to identify and address any sensor that joined the network without the use of any centralized database defining the sensors characteristics. The IEEE 1451 Standard defines methods for the management of intelligent sensor systems and the IEEE 1451.4 section defines Transducer Electronic Datasheets (TEDS), which contain key information regarding the sensor characteristics such as name, description, serial number, calibration information and user information such as location within a vehicle. By locating the TEDS information on the wireless sensor itself and enabling access to this information base from the application software, the application can identify the sensor unambiguously and interpret and present the sensor data stream without reference to any other information. The application software is able to read the status of each sensor module, responding in real-time to changes of

  3. Multi-platform laser communication networking optical antenna system design

    NASA Astrophysics Data System (ADS)

    Zhang, Tao

    2016-10-01

    In this paper, a new conclusion based on rotating parabolic model and a different scheme of laser communication networking antenna system has been put forward in the paper. Based on rotating parabolic antenna, a new theory of the optical properties have been deduced, which can realize larger dynamic, duplex, networking communications among multiple platforms in 360° azimuth and pitch range. Meanwhile, depending on the operation mode of the system, multiple mathematical optimization models have been established. Tracking communication range, emission energy efficiency and receiving energy efficiency have been analyzed and optimized. Relationship among opening up and low apertures, the lens unit aperture, focal length of lens unit as well as rotating parabolic focal length have been analyzed. Tracking pitching range and emission energy utilization has carried on the theoretical derivation and optimization and networking platform link between energy receiver and transmitter has been analyzed. Taking some parameters of this new system into calculation, optimized results can be utilized with MATLAB software for its application and system of communication engineering. The rotating parabolic internal can form a hollow structure, which is utilized for miniaturization, light-weighted design and realize duplex communication in a wide range and distance. Circular orbit guidance is the modern way used in dynamic tracking system. The new theory and optical antenna system has widespread applications value as well.

  4. Using a CLIPS expert system to automatically manage TCP/IP networks and their components

    NASA Technical Reports Server (NTRS)

    Faul, Ben M.

    1991-01-01

    A expert system that can directly manage networks components on a Transmission Control Protocol/Internet Protocol (TCP/IP) network is described. Previous expert systems for managing networks have focused on managing network faults after they occur. However, this proactive expert system can monitor and control network components in near real time. The ability to directly manage network elements from the C Language Integrated Production System (CLIPS) is accomplished by the integration of the Simple Network Management Protocol (SNMP) and a Abstract Syntax Notation (ASN) parser into the CLIPS artificial intelligence language.

  5. Implementation of medical monitor system based on networks

    NASA Astrophysics Data System (ADS)

    Yu, Hui; Cao, Yuzhen; Zhang, Lixin; Ding, Mingshi

    2006-11-01

    In this paper, the development trend of medical monitor system is analyzed and portable trend and network function become more and more popular among all kinds of medical monitor devices. The architecture of medical network monitor system solution is provided and design and implementation details of medical monitor terminal, monitor center software, distributed medical database and two kind of medical information terminal are especially discussed. Rabbit3000 system is used in medical monitor terminal to implement security administration of data transfer on network, human-machine interface, power management and DSP interface while DSP chip TMS5402 is used in signal analysis and data compression. Distributed medical database is designed for hospital center according to DICOM information model and HL7 standard. Pocket medical information terminal based on ARM9 embedded platform is also developed to interactive with center database on networks. Two kernels based on WINCE are customized and corresponding terminal software are developed for nurse's routine care and doctor's auxiliary diagnosis. Now invention patent of the monitor terminal is approved and manufacture and clinic test plans are scheduled. Applications for invention patent are also arranged for two medical information terminals.

  6. Network representation of dynamical systems: Connectivity patterns, information and predictability

    NASA Astrophysics Data System (ADS)

    García Cantú Ros, A.; Forti, G.; Nicolis, G.

    2013-08-01

    The present work elaborates on predictability and information aspects of dynamical systems, in connection with the connectivity features of their network representation. The basic idea underlying this work is to map the set of coarse-grained states of a dynamical system onto a set of network nodes and transitions between them onto a set of network links. Based on the vertex centrality of these nodes, we define (a) a local indicator of predictability, (b) a measure of the information that is available about the state of the system after one transition occurring within an arbitrary long time window and (c) an upper bound for the time horizon of predictability. We address the cases of the tent and the cusp maps, as representative examples of Markov and non-Markov processes. An analytical exact result for the horizon of predictability is obtained for the tent map, as well as for its higher iterates, and its connection with the corresponding network diameters is discussed. Similarly, analytical expressions are derived for the bounds of the predictability horizon in the case of the cusp map.

  7. Enabling information management systems in tactical network environments

    NASA Astrophysics Data System (ADS)

    Carvalho, Marco; Uszok, Andrzej; Suri, Niranjan; Bradshaw, Jeffrey M.; Ceccio, Philip J.; Hanna, James P.; Sinclair, Asher

    2009-05-01

    Net-Centric Information Management (IM) and sharing in tactical environments promises to revolutionize forward command and control capabilities by providing ubiquitous shared situational awareness to the warfighter. This vision can be realized by leveraging the tactical and Mobile Ad hoc Networks (MANET) which provide the underlying communications infrastructure, but, significant technical challenges remain. Enabling information management in these highly dynamic environments will require multiple support services and protocols which are affected by, and highly dependent on, the underlying capabilities and dynamics of the tactical network infrastructure. In this paper we investigate, discuss, and evaluate the effects of realistic tactical and mobile communications network environments on mission-critical information management systems. We motivate our discussion by introducing the Advanced Information Management System (AIMS) which is targeted for deployment in tactical sensor systems. We present some operational requirements for AIMS and highlight how critical IM support services such as discovery, transport, federation, and Quality of Service (QoS) management are necessary to meet these requirements. Our goal is to provide a qualitative analysis of the impact of underlying assumptions of availability and performance of some of the critical services supporting tactical information management. We will also propose and describe a number of technologies and capabilities that have been developed to address these challenges, providing alternative approaches for transport, service discovery, and federation services for tactical networks.

  8. Networked Microgrids for Self-healing Power Systems

    SciTech Connect

    Wang, Zhaoyu; Chen, Bokan; Wang, Jianhui; Chen, Chen

    2015-06-17

    This paper proposes a transformative architecture for the normal operation and self-healing of networked microgrids (MGs). MGs can support and interchange electricity with each other in the proposed infrastructure. The networked MGs are connected by a physical common bus and a designed two-layer cyber communication network. The lower layer is within each MG where the energy management system (EMS) schedules the MG operation; the upper layer links a number of EMSs for global optimization and communication. In the normal operation mode, the objective is to schedule dispatchable distributed generators (DGs), energy storage systems (ESs) and controllable loads to minimize the operation costs and maximize the supply adequacy of each MG. When a generation deficiency or fault happens in a MG, the model switches to the self-healing mode and the local generation capacities of other MGs can be used to support the on-emergency portion of the system. A consensus algorithm is used to distribute portions of the desired power support to each individual MG in a decentralized way. The allocated portion corresponds to each MG’s local power exchange target which is used by its EMS to perform the optimal schedule. The resultant aggregated power output of networked MGs will be used to provide the requested power support. Test cases demonstrate the effectiveness of the proposed methodology.

  9. Green pathways: Metabolic network analysis of plant systems.

    PubMed

    Dersch, Lisa Maria; Beckers, Veronique; Wittmann, Christoph

    2016-03-01

    Metabolic engineering of plants with enhanced crop yield and value-added compositional traits is particularly challenging as they probably exhibit the highest metabolic network complexity of all living organisms. Therefore, approaches of plant metabolic network analysis, which can provide systems-level understanding of plant physiology, appear valuable as guidance for plant metabolic engineers. Strongly supported by the sequencing of plant genomes, a number of different experimental and computational methods have emerged in recent years to study plant systems at various levels: from heterotrophic cell cultures to autotrophic entire plants. The present review presents a state-of-the-art toolbox for plant metabolic network analysis. Among the described approaches are different in silico modeling techniques, including flux balance analysis, elementary flux mode analysis and kinetic flux profiling, as well as different variants of experiments with plant systems which use radioactive and stable isotopes to determine in vivo plant metabolic fluxes. The fundamental principles of these techniques, the required data input and the obtained flux information are enriched by technical advices, specific to plants. In addition, pioneering and high-impacting findings of plant metabolic network analysis highlight the potential of the field.

  10. Nonlinear system identification based on internal recurrent neural networks.

    PubMed

    Puscasu, Gheorghe; Codres, Bogdan; Stancu, Alexandru; Murariu, Gabriel

    2009-04-01

    A novel approach for nonlinear complex system identification based on internal recurrent neural networks (IRNN) is proposed in this paper. The computational complexity of neural identification can be greatly reduced if the whole system is decomposed into several subsystems. This approach employs internal state estimation when no measurements coming from the sensors are available for the system states. A modified backpropagation algorithm is introduced in order to train the IRNN for nonlinear system identification. The performance of the proposed design approach is proven on a car simulator case study.

  11. Security framework for networked storage system based on artificial immune system

    NASA Astrophysics Data System (ADS)

    Huang, Jianzhong; Xie, Changsheng; Zhang, Chengfeng; Zhan, Ling

    2007-11-01

    This paper proposed a theoretical framework for the networked storage system addressing the storage security. The immune system is an adaptive learning system, which can recognize, classify and eliminate 'non-self' such as foreign pathogens. Thus, we introduced the artificial immune technique to the storage security research, and proposed a full theoretical framework for storage security system. Under this framework, it is possible to carry out the quantitative evaluation for the storage security system using modeling language of artificial immune system (AIS), and the evaluation can offer security consideration for the deployment of networked storage system. Meanwhile, it is potential to obtain the active defense technique suitable for networked storage system via exploring the principle of AIS and achieve a highly secure storage system with immune characteristic.

  12. Artificial synapse network on inorganic proton conductor for neuromorphic systems

    NASA Astrophysics Data System (ADS)

    Zhu, Li Qiang; Wan, Chang Jin; Guo, Li Qiang; Shi, Yi; Wan, Qing

    2014-01-01

    The basic units in our brain are neurons, and each neuron has more than 1,000 synapse connections. Synapse is the basic structure for information transfer in an ever-changing manner, and short-term plasticity allows synapses to perform critical computational functions in neural circuits. Therefore, the major challenge for the hardware implementation of neuromorphic computation is to develop artificial synapse network. Here in-plane lateral-coupled oxide-based artificial synapse network coupled by proton neurotransmitters are self-assembled on glass substrates at room-temperature. A strong lateral modulation is observed due to the proton-related electrical-double-layer effect. Short-term plasticity behaviours, including paired-pulse facilitation, dynamic filtering and spatiotemporally correlated signal processing are mimicked. Such laterally coupled oxide-based protonic/electronic hybrid artificial synapse network proposed here is interesting for building future neuromorphic systems.

  13. Artificial synapse network on inorganic proton conductor for neuromorphic systems.

    PubMed

    Zhu, Li Qiang; Wan, Chang Jin; Guo, Li Qiang; Shi, Yi; Wan, Qing

    2014-01-01

    The basic units in our brain are neurons, and each neuron has more than 1,000 synapse connections. Synapse is the basic structure for information transfer in an ever-changing manner, and short-term plasticity allows synapses to perform critical computational functions in neural circuits. Therefore, the major challenge for the hardware implementation of neuromorphic computation is to develop artificial synapse network. Here in-plane lateral-coupled oxide-based artificial synapse network coupled by proton neurotransmitters are self-assembled on glass substrates at room-temperature. A strong lateral modulation is observed due to the proton-related electrical-double-layer effect. Short-term plasticity behaviours, including paired-pulse facilitation, dynamic filtering and spatiotemporally correlated signal processing are mimicked. Such laterally coupled oxide-based protonic/electronic hybrid artificial synapse network proposed here is interesting for building future neuromorphic systems.

  14. Characterizing global evolutions of complex systems via intermediate network representations

    NASA Astrophysics Data System (ADS)

    Iwayama, Koji; Hirata, Yoshito; Takahashi, Kohske; Watanabe, Katsumi; Aihara, Kazuyuki; Suzuki, Hideyuki

    2012-05-01

    Recent developments in measurement techniques have enabled us to observe the time series of many components simultaneously. Thus, it is important to understand not only the dynamics of individual time series but also their interactions. Although there are many methods for analysing the interaction between two or more time series, there are very few methods that describe global changes of the interactions over time. Here, we propose an approach to visualise time evolution for the global changes of the interactions in complex systems. This approach consists of two steps. In the first step, we construct a meta-time series of networks. In the second step, we analyse and visualise this meta-time series by using distance and recurrence plots. Our two-step approach involving intermediate network representations elucidates the half-a-day periodicity of foreign exchange markets and a singular functional network in the brain related to perceptual alternations.

  15. Default Cascades in Complex Networks: Topology and Systemic Risk

    PubMed Central

    Roukny, Tarik; Bersini, Hugues; Pirotte, Hugues; Caldarelli, Guido; Battiston, Stefano

    2013-01-01

    The recent crisis has brought to the fore a crucial question that remains still open: what would be the optimal architecture of financial systems? We investigate the stability of several benchmark topologies in a simple default cascading dynamics in bank networks. We analyze the interplay of several crucial drivers, i.e., network topology, banks' capital ratios, market illiquidity, and random vs targeted shocks. We find that, in general, topology matters only – but substantially – when the market is illiquid. No single topology is always superior to others. In particular, scale-free networks can be both more robust and more fragile than homogeneous architectures. This finding has important policy implications. We also apply our methodology to a comprehensive dataset of an interbank market from 1999 to 2011. PMID:24067913

  16. Development of the network architecture of the Canadian MSAT system

    NASA Technical Reports Server (NTRS)

    Davies, N. George; Shoamanesh, Alireza; Leung, Victor C. M.

    1988-01-01

    A description is given of the present concept for the Canadian Mobile Satellite (MSAT) System and the development of the network architecture which will accommodate the planned family of three categories of service: a mobile radio service (MRS), a mobile telephone service (MTS), and a mobile data service (MDS). The MSAT satellite will have cross-strapped L-band and Ku-band transponders to provide communications services between L-band mobile terminals and fixed base stations supporting dispatcher-type MRS, gateway stations supporting MTS interconnections to the public telephone network, data hub stations supporting the MDS, and the network control center. The currently perceived centralized architecture with demand assignment multiple access for the circuit switched MRS, MTS and permanently assigned channels for the packet switched MDS is discussed.

  17. Discovery of Chemical Toxicity via Biological Networks and Systems Biology

    SciTech Connect

    Perkins, Edward; Habib, Tanwir; Guan, Xin; Escalon, Barbara; Falciani, Francesco; Chipman, J.K.; Antczak, Philipp; Edwards, Stephen; Taylor, Ronald C.; Vulpe, Chris; Loguinov, Alexandre; Van Aggelen, Graham; Villeneuve, Daniel L.; Garcia-Reyero, Natalia

    2010-09-30

    Both soldiers and animals are exposed to many chemicals as the result of military activities. Tools are needed to understand the hazards and risks that chemicals and new materials pose to soldiers and the environment. We have investigated the potential of global gene regulatory networks in understanding the impact of chemicals on reproduction. We characterized effects of chemicals on ovaries of the model animal system, the Fathead minnow (Pimopheles promelas) connecting chemical impacts on gene expression to circulating blood levels of the hormones testosterone and estradiol in addition to the egg yolk protein vitellogenin. We describe the application of reverse engineering complex interaction networks from high dimensional gene expression data to characterize chemicals that disrupt the hypothalamus-pituitary-gonadal endocrine axis that governs reproduction in fathead minnows. The construction of global gene regulatory networks provides deep insights into how drugs and chemicals effect key organs and biological pathways.

  18. Interference Mitigation for Cyber-Physical Wireless Body Area Network System Using Social Networks.

    PubMed

    Zhang, Zhaoyang; Wang, Honggang; Wang, Chonggang; Fang, Hua

    2013-06-01

    Wireless body area networks (WBANs) are cyber-physical systems (CPS) that have emerged as a key technology to provide real-time health monitoring and ubiquitous healthcare services. WBANs could operate in dense environments such as in a hospital and lead to a high mutual communication interference in many application scenarios. The excessive interferences will significantly degrade the network performance including depleting the energy of WBAN nodes more quickly, and even eventually jeopardize people's lives due to unreliable (caused by the interference) healthcare data collections. Therefore, It is critical to mitigate the interference among WBANs to increase the reliability of the WBAN system while minimizing the system power consumption. Many existing approaches can deal with communication interference mitigation in general wireless networks but are not suitable for WBANs due to their ignoring the social nature of WBANs. Unlike the previous research, we for the first time propose a power game based approach to mitigate the communication interferences for WBANs based on the people's social interaction information. Our major contributions include: (1) model the inter-WBANs interference, and determine the distance distribution of the interference through both theoretical analysis and Monte Carlo simulations; (2) develop social interaction detection and prediction algorithms for people carrying WBANs; (3) develop a power control game based on the social interaction information to maximize the system's utility while minimize the energy consumption of WBANs system. The extensive simulation results show the effectiveness of the power control game for inter-WBAN interference mitigation using social interaction information. Our research opens a new research vista of WBANs using social networks.

  19. Network Randomization and Dynamic Defense for Critical Infrastructure Systems

    SciTech Connect

    Chavez, Adrian R.; Martin, Mitchell Tyler; Hamlet, Jason; Stout, William M.S.; Lee, Erik

    2015-04-01

    Critical Infrastructure control systems continue to foster predictable communication paths, static configurations, and unpatched systems that allow easy access to our nation's most critical assets. This makes them attractive targets for cyber intrusion. We seek to address these attack vectors by automatically randomizing network settings, randomizing applications on the end devices themselves, and dynamically defending these systems against active attacks. Applying these protective measures will convert control systems into moving targets that proactively defend themselves against attack. Sandia National Laboratories has led this effort by gathering operational and technical requirements from Tennessee Valley Authority (TVA) and performing research and development to create a proof-of-concept solution. Our proof-of-concept has been tested in a laboratory environment with over 300 nodes. The vision of this project is to enhance control system security by converting existing control systems into moving targets and building these security measures into future systems while meeting the unique constraints that control systems face.

  20. A graph-based network-vulnerability analysis system

    SciTech Connect

    Swiler, L.P.; Phillips, C.; Gaylor, T.

    1998-01-01

    This report presents a graph-based approach to network vulnerability analysis. The method is flexible, allowing analysis of attacks from both outside and inside the network. It can analyze risks to a specific network asset, or examine the universe of possible consequences following a successful attack. The analysis system requires as input a database of common attacks, broken into atomic steps, specific network configuration and topology information, and an attacker profile. The attack information is matched with the network configuration information and an attacker profile to create a superset attack graph. Nodes identify a stage of attack, for example the class of machines the attacker has accessed and the user privilege level he or she has compromised. The arcs in the attack graph represent attacks or stages of attacks. By assigning probabilities of success on the arcs or costs representing level-of-effort for the attacker, various graph algorithms such as shortest-path algorithms can identify the attack paths with the highest probability of success.

  1. Scaling the Earth System Grid to 100Gbps Networks

    SciTech Connect

    Balman, Mehmet; Sim, Alex

    2012-03-02

    The SC11 demonstration, titled Scaling the Earth System Grid to 100Gbps Networks, showed the ability to use underlying infrastructure for the movement of climate data over 100Gbps network. Climate change research is one of the critical data intensive sciences, and the amount of data is continuously growing. Climate simulation data is geographically distributed over the world, and it needs to be accessed from many sources for fast and efficient analysis and inter-comparison of simulations. We used a 100Gbps link connecting National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory (LBNL), Argonne National Laboratory (ANL) and Oak Ridge National Laboratory (ORNL). In the demo, the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) phase 3 of the Coupled Model Intercomparison Project (CMIP-3) dataset was staged into the memory of computing nodes at ANL and ORNL from NERSC over the 100Gbps network for analysis and visualization. In general, climate simulation data consists of relatively small and large files with irregular file size distribution in each dataset. In this demo, we addressed challenges on data management in terms of high bandwidth networks, usability of existing protocols and middleware tools, and how applications can adapt and benefit from next generation networks.

  2. NNIC—neural network image compressor for satellite positioning system

    NASA Astrophysics Data System (ADS)

    Danchenko, Pavel; Lifshits, Feodor; Orion, Itzhak; Koren, Sion; Solomon, Alan D.; Mark, Shlomo

    2007-04-01

    We have developed an algorithm, based on novel techniques of data compression and neural networks for the optimal positioning of a satellite. The algorithm is described in detail, and examples of its application are given. The heart of this algorithm is the program NNIC—neural network image compressor. This program was developed for compression color and grayscale images with artificial neural networks (ANNs). NNIC applies three different methods for compression. Two of them are based on neural networks architectures—multilayer perceptron and kohonen network. The third is based on a widely used method of discrete cosine transform, the basis for the JPEG standard. The program also serves as a tool for determining numerical and visual quality parameters of compression and comparison between different methods. A number of advantages and disadvantages of the compression using ANNs were discovered in the course of the present research, some of them presented in this report. The thrust of the report is the discussion of ANNs implementation problems for modern platforms, such as a satellite positioning system that include intensive image flowing and processing.

  3. Power consumption analysis of operating systems for wireless sensor networks.

    PubMed

    Lajara, Rafael; Pelegrí-Sebastiá, José; Perez Solano, Juan J

    2010-01-01

    In this paper four wireless sensor network operating systems are compared in terms of power consumption. The analysis takes into account the most common operating systems--TinyOS v1.0, TinyOS v2.0, Mantis and Contiki--running on Tmote Sky and MICAz devices. With the objective of ensuring a fair evaluation, a benchmark composed of four applications has been developed, covering the most typical tasks that a Wireless Sensor Network performs. The results show the instant and average current consumption of the devices during the execution of these applications. The experimental measurements provide a good insight into the power mode in which the device components are running at every moment, and they can be used to compare the performance of different operating systems executing the same tasks.

  4. Identifying Vulnerabilities and Hardening Attack Graphs for Networked Systems

    SciTech Connect

    Saha, Sudip; Vullinati, Anil K.; Halappanavar, Mahantesh; Chatterjee, Samrat

    2016-09-15

    We investigate efficient security control methods for protecting against vulnerabilities in networked systems. A large number of interdependent vulnerabilities typically exist in the computing nodes of a cyber-system; as vulnerabilities get exploited, starting from low level ones, they open up the doors to more critical vulnerabilities. These cannot be understood just by a topological analysis of the network, and we use the attack graph abstraction of Dewri et al. to study these problems. In contrast to earlier approaches based on heuristics and evolutionary algorithms, we study rigorous methods for quantifying the inherent vulnerability and hardening cost for the system. We develop algorithms with provable approximation guarantees, and evaluate them for real and synthetic attack graphs.

  5. Automatic Identification System (AIS) Collection and Reach-back System: System Description

    DTIC Science & Technology

    2014-08-20

    Technologic Systems Inc. • Model: TS-7260 – 200 MHz ARM9 CPU, Fanless – Power Requirement: əW – 64 MB RAM, 128 MB Flash Memory – Support for Linux 2.6...satellite network. Note: max packet length is about 280 bytes • CRBSPLAY - Test module for replaying stored position and AIS data. This is a utility...3009 • com 19 start up – Reads command line and sets parameters in global memory – Initializes the receiver for function key F4 processing. Function

  6. New neural-networks-based 3D object recognition system

    NASA Astrophysics Data System (ADS)

    Abolmaesumi, Purang; Jahed, M.

    1997-09-01

    Three-dimensional object recognition has always been one of the challenging fields in computer vision. In recent years, Ulman and Basri (1991) have proposed that this task can be done by using a database of 2-D views of the objects. The main problem in their proposed system is that the correspondent points should be known to interpolate the views. On the other hand, their system should have a supervisor to decide which class does the represented view belong to. In this paper, we propose a new momentum-Fourier descriptor that is invariant to scale, translation, and rotation. This descriptor provides the input feature vectors to our proposed system. By using the Dystal network, we show that the objects can be classified with over 95% precision. We have used this system to classify the objects like cube, cone, sphere, torus, and cylinder. Because of the nature of the Dystal network, this system reaches to its stable point by a single representation of the view to the system. This system can also classify the similar views to a single class (e.g., for the cube, the system generated 9 different classes for 50 different input views), which can be used to select an optimum database of training views. The system is also very flexible to the noise and deformed views.

  7. Interference Mitigation for Cyber-Physical Wireless Body Area Network System Using Social Networks

    PubMed Central

    Zhang, Zhaoyang; Wang, Honggang; Wang, Chonggang; Fang, Hua

    2014-01-01

    Wireless body area networks (WBANs) are cyber-physical systems (CPS) that have emerged as a key technology to provide real-time health monitoring and ubiquitous healthcare services. WBANs could operate in dense environments such as in a hospital and lead to a high mutual communication interference in many application scenarios. The excessive interferences will significantly degrade the network performance including depleting the energy of WBAN nodes more quickly, and even eventually jeopardize people’s lives due to unreliable (caused by the interference) healthcare data collections. Therefore, It is critical to mitigate the interference among WBANs to increase the reliability of the WBAN system while minimizing the system power consumption. Many existing approaches can deal with communication interference mitigation in general wireless networks but are not suitable for WBANs due to their ignoring the social nature of WBANs. Unlike the previous research, we for the first time propose a power game based approach to mitigate the communication interferences for WBANs based on the people’s social interaction information. Our major contributions include: (1) model the inter-WBANs interference, and determine the distance distribution of the interference through both theoretical analysis and Monte Carlo simulations; (2) develop social interaction detection and prediction algorithms for people carrying WBANs; (3) develop a power control game based on the social interaction information to maximize the system’s utility while minimize the energy consumption of WBANs system. The extensive simulation results show the effectiveness of the power control game for inter-WBAN interference mitigation using social interaction information. Our research opens a new research vista of WBANs using social networks. PMID:25436180

  8. The Device Centric Communication System for 5G Networks

    NASA Astrophysics Data System (ADS)

    Biswash, S. K.; Jayakody, D. N. K.

    2017-01-01

    The Fifth Generation Communication (5G) networks have several functional features such as: Massive Multiple Input and Multiple Output (MIMO), Device centric data and voice support, Smarter-device communications, etc. The objective for 5G networks is to gain the 1000x more throughput, 10x spectral efficiency, 100 x more energy efficiency than existing technologies. The 5G system will provide the balance between the Quality of Experience (QoE) and the Quality of Service (QoS), without compromising the user benefit. The data rate has been the key metric for wireless QoS; QoE deals with the delay and throughput. In order to realize a balance between the QoS and QoE, we propose a cellular Device centric communication methodology for the overlapping network coverage area in the 5G communication system. The multiple beacon signals mobile tower refers to an overlapping network area, and a user must be forwarded to the next location area. To resolve this issue, we suggest the user centric methodology (without Base Station interface) to handover the device in the next area, until the users finalize the communication. The proposed method will reduce the signalling cost and overheads for the communication.

  9. A Flexible Behavioral Learning System with Modular Neural Networks

    NASA Astrophysics Data System (ADS)

    Takeuchi, Johane; Shouno, Osamu; Tsujino, Hiroshi

    Future robots/agents will perform situated behaviors for each user. Flexible behavioral learning is required for coping with diverse and unexpected users' situations. Unexpected situations are usually not tractable for machine learning systems that are designed for pre-defined problems. In order to realize such a flexible learning system, we were trying to create a learning model that can function in several different kinds of state transitions without specific adjustments for each transition as a first step. We constructed a modular neural network model based on reinforcement learning. We expected that combining a modular architecture with neural networks could accelerate the learning speed of neural networks. The inputs of our neural network model always include not only observed states but also memory information for any transition. In pure Markov decision processes, memory information is not necessary, rather it can lead to lower performance. On the other hand, partially observable conditions require memory information to select proper actions. We demonstrated that the new learning model could actually learn those multiple kinds of state transitions with the same architectures and parameters, and without pre-designed models of environments. This paper describes the performances of constructed models using probabilistically fluctuated Markov decision processes including partially observable conditions. In the test transitions, the observed state probabilistically fluctuated. The new learning model could function in those complex transitions. In addition, the learning speeds of our model are comparable to a reinforcement learning algorithm implemented with a pre-defined and optimized table-representation of states.

  10. End-System Network Interface Controller for 100 Gb/s Wide Area Networks: Final Report

    SciTech Connect

    Wen, Jesse

    2013-08-30

    In recent years, network bandwidth requirements have scaled multiple folds, pushing the need for the development of data exchange mechanisms at 100 Gb/s and beyond. High performance computing, climate modeling, large-scale storage, and collaborative scientific research are examples of applications that can greatly benefit by leveraging high bandwidth capabilities of the order of 100 Gb/s. Such requirements and advances in IEEE Ethernet standards, Optical Transport Unit4 (OTU4), and host-system interconnects demand a network infrastructure supporting throughput rates of the order of 100 Gb/s with a single wavelength. To address such a demand Acadia Optronics in collaboration with the University of New Mexico, proposed and developed a end-system Network Interface Controller (NIC) for the 100Gbps WANs. Acadia’s 100G NIC employs an FPGA based system with a high-performance processor interconnect (PCIe 3.0) and a high capacity optical transmission link (CXP) to provide data transmission at the rate of 100 Gbps.

  11. A secure network access system for mobile IPv6

    NASA Astrophysics Data System (ADS)

    Zhang, Hong; Yuan, Man; He, Rui; Jiang, Luliang; Ma, Jian; Qian, Hualin

    2004-03-01

    With the fast development of Internet and wireless and mobile communication technology, the Mobile Internet Age is upcoming. For those providing Mobile Internet services, especially from the view of ISP (Internet Service Provider), current mobile IP protocol is insufficient. Since the Mobile IPv6 protocol will be popular in near future, how to provide a secure mobile IPv6 service is important. A secure mobile IPv6 network access system is highly needed for mobile IPv6 deployment. Current methods and systems are still inadequate, including EAP, PANA, 802.1X, RADIUS, Diameter, etc. In this paper, we describe main security goals for a secure mobile IPv6 access system, and propose a secure network access system to achieve them. This access system consists of access router, attendant and authentication servers. The access procedure is divided into three phases, which are initial phase, authentication and registration phase and termination phase. This system has many advantages, including layer two independent, flexible and extensible, no need to modify current IPv6 address autoconfiguration protocols, binding update optimization, etc. Finally, the security of the protocol in this system is analyzed and proved with Extended BAN logic method, and a brief introduction of system implementation is given.

  12. Optical-digital-neural network system for aided target recognition

    NASA Astrophysics Data System (ADS)

    Farr, Keith B.; Hartman, Richard L.

    1995-07-01

    Many military systems have a critical need for aided target recognition, or cuing. This includes several systems with wide field-of-view search missions such as the UAV, EFOG-M, and Comanche. This report discusses one new approach: a multiple region of interest processor based on diffraction pattern sampling and digital neural network processing. In this concept an optical system segments the image into multiple, rectangular regions of interest and in parallel converts each ROI, be it visible, IR, or radar, to a spatial frequency power spectrum and samples that spectrum for 64 features. A neural network learns to correlate those features with target classes or identifications. A digital system uses the network weights to recognize unknown targets. The research discussed in this report using a single ROI processor showed a very high level of performance. Out of 1024 trials with models of five targets of F- 14, F-18, HIND, SCUD, and M1 tanks, there were 1023 correct classifications and 1 incorrect classification. Out of 1514 trials with those images plus 490 real clutter scenes, there were 1514 correct decisions between target or no-target. Of the 1024 target detections, there were 1023 correct classifications. Out of 60 trials with low resolution IR images of real scenes, there were 60 correct decisions between target and no-target. Of the 40 target detections, there were 40 correct classifications.

  13. A survey of visualization systems for network security.

    PubMed

    Shiravi, Hadi; Shiravi, Ali; Ghorbani, Ali A

    2012-08-01

    Security Visualization is a very young term. It expresses the idea that common visualization techniques have been designed for use cases that are not supportive of security-related data, demanding novel techniques fine tuned for the purpose of thorough analysis. Significant amount of work has been published in this area, but little work has been done to study this emerging visualization discipline. We offer a comprehensive review of network security visualization and provide a taxonomy in the form of five use-case classes encompassing nearly all recent works in this area. We outline the incorporated visualization techniques and data sources and provide an informative table to display our findings. From the analysis of these systems, we examine issues and concerns regarding network security visualization and provide guidelines and directions for future researchers and visual system developers.

  14. Power Consumption Analysis of Operating Systems for Wireless Sensor Networks

    PubMed Central

    Lajara, Rafael; Pelegrí-Sebastiá, José; Perez Solano, Juan J.

    2010-01-01

    In this paper four wireless sensor network operating systems are compared in terms of power consumption. The analysis takes into account the most common operating systems—TinyOS v1.0, TinyOS v2.0, Mantis and Contiki—running on Tmote Sky and MICAz devices. With the objective of ensuring a fair evaluation, a benchmark composed of four applications has been developed, covering the most typical tasks that a Wireless Sensor Network performs. The results show the instant and average current consumption of the devices during the execution of these applications. The experimental measurements provide a good insight into the power mode in which the device components are running at every moment, and they can be used to compare the performance of different operating systems executing the same tasks. PMID:22219688

  15. Cooperative water network system to reduce carbon footprint.

    PubMed

    Lim, Seong-Rin; Park, Jong Moon

    2008-08-15

    Much effort has been made in reducing the carbon footprint to mitigate climate change. However, water network synthesis has been focused on reducing the consumption and cost of freshwater within each industrial plant. The objective of this study is to illustrate the necessity of the cooperation of industrial plants to reduce the total carbon footprint of their water supply systems. A mathematical optimization model to minimize global warming potentials is developed to synthesize (1) a cooperative water network system (WNS) integrated over two plants and (2) an individual WNS consisting of two WNSs separated for each plant. The cooperative WNS is compared to the individual WNS. The cooperation reduces their carbon footprint and is economically feasible and profitable. A strategy for implementing the cooperation is suggested for the fair distribution of costs and benefits. As a consequence, industrial plants should cooperate with their neighbor plants to further reduce the carbon footprint.

  16. The Felin soldier system: a tailored solution for networked operations

    NASA Astrophysics Data System (ADS)

    Le Sueur, Philippe

    2007-04-01

    Sagem Defense Securite has been awarded a 800M euro contract for the French infantrymen modernisation programme. This programme covers the development, the qualification and the production of about 32 000 soldier systems to equip all the French infantry starting fielding in 2008. The FELIN soldier system provides the infantryman with an integrated system increasing dramatically the soldier capability in any dismounted close combat domains. Man remains at the centre of the system, which can interface equipments or systems already fielded and future equipments to match any customer's needs. Urban operations are carefully addressed thanks to a versatile and modular solution and a dedicated C4I system, Sagem Defense Securite is a European leader in defence electronics and takes part of this major French Army transformation programme, which will play a key role in the Info Centric Network initiatives promoted in France and other countries. This paper summarises the system solutions selected by the French Army with a focus on the networked capabilities and the optronic devices.

  17. Scheduling of network access for feedback-based embedded systems

    NASA Astrophysics Data System (ADS)

    Liberatore, Vincenzo

    2002-07-01

    nd communication capabilities. Examples range from smart dust embedded in building materials to networks of appliances in the home. Embedded devices will be deployed in unprecedented numbers, will enable pervasive distributed computing, and will radically change the way people interact with the surrounding environment [EGH00a]. The paper targets embedded systems and their real-time (RT) communication requirements. RT requirements arise from the

  18. Some new results on system identification with dynamic neural networks.

    PubMed

    Yu, W; Li, X

    2001-01-01

    Nonlinear system online identification via dynamic neural networks is studied in this paper. The main contribution of the paper is that the passivity approach is applied to access several new stable properties of neuro identification. The conditions for passivity, stability, asymptotic stability, and input-to-state stability are established in certain senses. We conclude that the gradient descent algorithm for weight adjustment is stable in an L(infinity) sense and robust to any bounded uncertainties.

  19. Security Considerations For Network-Centric Weapon Systems

    DTIC Science & Technology

    2009-09-01

    Communication started with runners and flag signals , evolved into radio voice messages, grew to include written messages delivered by ground or...the entire force. The availability of this information drives a paradigm shift where units are considered nodes in a network rather than stand...computer security focuses on the latter type of system. These systems—the ones using x86-based processors from Intel or AMD, Windows or Unix -based

  20. The Use and Significance of a Research Networking System

    PubMed Central

    Yuan, Leslie; Daigre, John; Meeks, Eric; Nelson, Katie; Piontkowski, Cynthia; Reuter, Katja; Sak, Rachael; Turner, Brian; Weber, Griffin M; Chatterjee, Anirvan

    2014-01-01

    Background Universities have begun deploying public Internet systems that allow for easy search of their experts, expertise, and intellectual networks. Deployed first in biomedical schools but now being implemented more broadly, the initial motivator of these research networking systems was to enable easier identification of collaborators and enable the development of teams for research. Objective The intent of the study was to provide the first description of the usage of an institutional research “social networking” system or research networking system (RNS). Methods Number of visits, visitor location and type, referral source, depth of visit, search terms, and click paths were derived from 2.5 years of Web analytics data. Feedback from a pop-up survey presented to users over 15 months was summarized. Results RNSs automatically generate and display profiles and networks of researchers. Within 2.5 years, the RNS at the University of California, San Francisco (UCSF) achieved one-seventh of the monthly visit rate of the main longstanding university website, with an increasing trend. Visitors came from diverse locations beyond the institution. Close to 75% (74.78%, 208,304/278,570) came via a public search engine and 84.0% (210 out of a sample of 250) of these queried an individual’s name that took them directly to the relevant profile page. In addition, 20.90% (214 of 1024) visits went beyond the page related to a person of interest to explore related researchers and topics through the novel and networked information provided by the tool. At the end of the period analyzed, more than 2000 visits per month traversed 5 or more links into related people and topics. One-third of visits came from returning visitors who were significantly more likely to continue to explore networked people and topics (P<.001). Responses to an online survey suggest a broad range of benefits of using the RNS in supporting the research and clinical mission. Conclusions Returning

  1. NASA's Deep Space Network and ESA's Tracking Network Collaboration to Enable Solar System Exploration

    NASA Astrophysics Data System (ADS)

    Asmar, Sami; Accomazzo, Andrea; Firre, Daniel; Ferri, Paolo; Liebrecht, Phil; Mann, Greg; Morse, Gary; Costrell, Jim; Kurtik, Susan; Hell, Wolfgang; Warhaut, Manfred

    2016-07-01

    Planetary missions travel vast distances in the solar system to explore and answer important scientific questions. To return the data containing their discoveries, communications challenges have to be overcome, namely the relatively low transmitter power, typically 20 Watts at X-band, and the one-over-the-square of the distance loss of the received power, among other factors. These missions were enabled only when leading space agencies developed very large communications antennas to communicate with them as well as provide radio-metric navigation tools. NASA's Deep Space Network (DSN) and ESA's ESTRACK network are distributed geographically in order to provide global coverage and utilize stations ranging in size from 34 m to 70 m in diameter. With the increasing number of missions and significant loading on networks' capacity, unique requirements during critical events, and long-baseline interferometry navigation techniques, it became obvious that collaboration between the networks was necessary and in the interest of both agencies and the advancement of planetary and space sciences. NASA and ESA established methods for collaboration that include a generic cross-support agreement as well as mission-specific memoranda of understanding. This collaboration also led to the development of international inter-operability standards. As a result of its success, the DSN-ESTRACK cross support approach is serving as a model for other agencies with similar stations and an interest in collaboration. Over recent years, many critical events were supported and some scientific breakthroughs in planetary science were enabled. This paper will review selected examples of the science resulting from this work and the overall benefits for deep space exploration, including lessons learned, from inter-agency collaboration with communications networks.

  2. Innovative Active Networking Services

    DTIC Science & Technology

    2004-03-01

    Integrating IKE We use the “ pluto ” implementation from Freeswan [Freeswan] as our IKE module. Pluto runs as a daemon on a Linux Network node. This base...implementation though incomplete with respect to some features of IKE is still sufficient in order to inter-operate with other pluto implementations...and many other IKE 30 implementations. Commands to pluto are given using a control interface to the daemon, called “whack”. Pluto uses either shared

  3. A multi-agent system architecture for sensor networks.

    PubMed

    Fuentes-Fernández, Rubén; Guijarro, María; Pajares, Gonzalo

    2009-01-01

    The design of the control systems for sensor networks presents important challenges. Besides the traditional problems about how to process the sensor data to obtain the target information, engineers need to consider additional aspects such as the heterogeneity and high number of sensors, and the flexibility of these networks regarding topologies and the sensors in them. Although there are partial approaches for resolving these issues, their integration relies on ad hoc solutions requiring important development efforts. In order to provide an effective approach for this integration, this paper proposes an architecture based on the multi-agent system paradigm with a clear separation of concerns. The architecture considers sensors as devices used by an upper layer of manager agents. These agents are able to communicate and negotiate services to achieve the required functionality. Activities are organized according to roles related with the different aspects to integrate, mainly sensor management, data processing, communication and adaptation to changes in the available devices and their capabilities. This organization largely isolates and decouples the data management from the changing network, while encouraging reuse of solutions. The use of the architecture is facilitated by a specific modelling language developed through metamodelling. A case study concerning a generic distributed system for fire fighting illustrates the approach and the comparison with related work.

  4. A Multi-Agent System Architecture for Sensor Networks

    PubMed Central

    Fuentes-Fernández, Rubén; Guijarro, María; Pajares, Gonzalo

    2009-01-01

    The design of the control systems for sensor networks presents important challenges. Besides the traditional problems about how to process the sensor data to obtain the target information, engineers need to consider additional aspects such as the heterogeneity and high number of sensors, and the flexibility of these networks regarding topologies and the sensors in them. Although there are partial approaches for resolving these issues, their integration relies on ad hoc solutions requiring important development efforts. In order to provide an effective approach for this integration, this paper proposes an architecture based on the multi-agent system paradigm with a clear separation of concerns. The architecture considers sensors as devices used by an upper layer of manager agents. These agents are able to communicate and negotiate services to achieve the required functionality. Activities are organized according to roles related with the different aspects to integrate, mainly sensor management, data processing, communication and adaptation to changes in the available devices and their capabilities. This organization largely isolates and decouples the data management from the changing network, while encouraging reuse of solutions. The use of the architecture is facilitated by a specific modelling language developed through metamodelling. A case study concerning a generic distributed system for fire fighting illustrates the approach and the comparison with related work. PMID:22303172

  5. Structures of systems 1. Cohomology of manufacturing and supply network-like systems

    NASA Astrophysics Data System (ADS)

    Macfarlane, Andrew

    2014-07-01

    Understanding the relation between large-scale and small-scale functionality is an acute problem in large systems. This paper presents possible structures that capture those relations. Here "structure" means a functor on a category, in this case the category of "combinatorial systems" that model manufacturing systems and supply networks. The details of the dynamics of these systems are frequently the domain of specialists and are ill understood outside such areas. Clustering activities in subsystems introduces covers as scales of analysis. This allows the development of sheaves of schedules and their properties which are analyzed by an adaptation of Čech cohomology. These are applied in supply networks to characterize the fragmentation of these networks and to characterize the conditions for local changes in schedules to extend to the whole system. The intent of this paper is to see sheaves and their cohomology as analytical probes that can enhance our understanding of large-scale systems.

  6. Ocean Networks Canada: Live Sensing of a Dynamic Ocean System

    NASA Astrophysics Data System (ADS)

    Heesemann, Martin; Juniper, Kim; Hoeberechts, Maia; Matabos, Marjolaine; Mihaly, Steven; Scherwath, Martin; Dewey, Richard

    2013-04-01

    Ocean Networks Canada operates two advanced cabled networks on the west coast of British Columbia. VENUS, the coastal network consisting of two cabled arrays with four Nodes reaching an isolated fjord (Saanich Inlet) and a busy shipping corridor near Vancouver (the Strait of Georgia) went into operation in February 2006. NEPTUNE Canada is the first operational deep-sea regional cabled ocean observatory worldwide. Since the first data began streaming to the public in 2009, instruments on the five active nodes along the 800 km cable loop have gathered a time-series documenting three years in the northeastern Pacific. Observations cover the northern Juan de Fuca tectonic plate from ridge to trench and the continental shelf and slope off Vancouver Island. The cabled systems provide power and high bandwidth communications to a wide range of oceanographic instrument systems which measure the physical, chemical, geological, and biological conditions of the dynamic earth-ocean system. Over the years significant challenges have been overcome and currently we have more than 100 instruments with hundreds of sensors reporting data in real-time. Salient successes are the first open-ocean seafloor to sea-surface vertical profiling system, three years of operation of Wally—a seafloor crawler that explores a hydrate mound, and a proven resilient cable design that can recover from trawler hits and major equipment meltdown with minimal loss of data. A network wide array of bottom mounted pressure recorders and seismometers recorded the passage of three major tsunamis, numerous earthquakes and frequent whale calls. At the Endeavour segment of the Juan de Fuca ridge high temperature and diffuse vent fluids were monitored and sampled using novel equipment, including high resolution active acoustics instrumentation to study plume dynamics at a massive sulfide hydrothermal vent. Also, four deep sea cabled moorings (300 m high) were placed in the precipitous bathymetry of the 2200 m

  7. Perturbation biology: inferring signaling networks in cellular systems.

    PubMed

    Molinelli, Evan J; Korkut, Anil; Wang, Weiqing; Miller, Martin L; Gauthier, Nicholas P; Jing, Xiaohong; Kaushik, Poorvi; He, Qin; Mills, Gordon; Solit, David B; Pratilas, Christine A; Weigt, Martin; Braunstein, Alfredo; Pagnani, Andrea; Zecchina, Riccardo; Sander, Chris

    2013-01-01

    We present a powerful experimental-computational technology for inferring network models that predict the response of cells to perturbations, and that may be useful in the design of combinatorial therapy against cancer. The experiments are systematic series of perturbations of cancer cell lines by targeted drugs, singly or in combination. The response to perturbation is quantified in terms of relative changes in the measured levels of proteins, phospho-proteins and cellular phenotypes such as viability. Computational network models are derived de novo, i.e., without prior knowledge of signaling pathways, and are based on simple non-linear differential equations. The prohibitively large solution space of all possible network models is explored efficiently using a probabilistic algorithm, Belief Propagation (BP), which is three orders of magnitude faster than standard Monte Carlo methods. Explicit executable models are derived for a set of perturbation experiments in SKMEL-133 melanoma cell lines, which are resistant to the therapeutically important inhibitor of RAF kinase. The resulting network models reproduce and extend known pathway biology. They empower potential discoveries of new molecular interactions and predict efficacious novel drug perturbations, such as the inhibition of PLK1, which is verified experimentally. This technology is suitable for application to larger systems in diverse areas of molecular biology.

  8. Living ordered neural networks as model systems for signal processing

    NASA Astrophysics Data System (ADS)

    Villard, C.; Amblard, P. O.; Becq, G.; Gory-Fauré, S.; Brocard, J.; Roth, S.

    2007-06-01

    Neural circuit architecture is a fundamental characteristic of the brain, and how architecture is bound to biological functions is still an open question. Some neuronal geometries seen in the retina or the cochlea are intriguing: information is processed in parallel by several entities like in "pooling" networks which have recently drawn the attention of signal processing scientists. These systems indeed exhibit the noise-enhanced processing effect, which is also actively discussed in the neuroscience community at the neuron scale. The aim of our project is to use in-vitro ordered neuron networks as living paradigms to test ideas coming from the computational science. The different technological bolts that have to be solved are enumerated and the first results are presented. A neuron is a polarised cell, with an excitatory axon and a receiving dendritic tree. We present how soma confinement and axon differentiation can be induced by surface functionalization techniques. The recording of large neuron networks, ordered or not, is also detailed and biological signals shown. The main difficulty to access neural noise in the case of weakly connected networks grown on micro electrode arrays is explained. This open the door to a new detection technology suitable for sub-cellular analysis and stimulation, whose development will constitute the next step of this project.

  9. The Network Library System: The History and Description of an Evolving Library-Developed System.

    ERIC Educational Resources Information Center

    Senzig, Donna M.; Bright, Franklyn F.

    1987-01-01

    Describes the Network Library System, a collaborative development project undertaken by the University of Wisconsin-Madison and University of Chicago libraries, which currently handles an online catalog and a circulation system. The conceptualization of the system, its development and performance, and subsequent changes due to available…

  10. Distributed Interplanetary Delay/Disruption Tolerant Network (DTN) Monitor and Control System

    NASA Technical Reports Server (NTRS)

    Wang, Shin-Ywan

    2012-01-01

    The main purpose of Distributed interplanetary Delay Tolerant Network Monitor and Control System as a DTN system network management implementation in JPL is defined to provide methods and tools that can monitor the DTN operation status, detect and resolve DTN operation failures in some automated style while either space network or some heterogeneous network is infused with DTN capability. In this paper, "DTN Monitor and Control system in Deep Space Network (DSN)" exemplifies a case how DTN Monitor and Control system can be adapted into a space network as it is DTN enabled.

  11. Spacecraft power system controller based on neural network

    NASA Astrophysics Data System (ADS)

    El-madany, Hanaa T.; Fahmy, Faten H.; El-Rahman, Ninet M. A.; Dorrah, Hassen T.

    2011-09-01

    Neural control is a branch of the general field of intelligent control, which is based on the concept of artificial intelligence. This work presents the spacecraft orbit determination, dimensioning of the renewable power system, and mathematical modeling of spacecraft power system which are required for simulating the system. The complete system is simulated using MATLAB-SIMULINK. The NN controller outperform PID in the extreme range of non-linearity. Well trained neural controller can operate at different conditions of load current at different orbital periods without any tuning such in case of PID controller. So an artificial neural network (ANN) based model has been developed for the optimum operation of spacecraft power system. An ANN is trained using a back propagation with Levenberg-Marquardt algorithm. The best validation performance is obtained for mean square error is equal to 9.9962×10 -11 at epoch 637. The regression between the network output and the corresponding target is equal to 100% which means a high accuracy. NNC architecture gives satisfactory results with small number of neurons, hence better in terms of memory and time are required for NNC implementation. The results indicate that the proposed control unit using ANN can be successfully used for controlling the spacecraft power system in low earth orbit (LEO). Therefore, this technique is going to be a very useful tool for the interested designers in space field.

  12. Towards a new Mercator Observatory Control System

    NASA Astrophysics Data System (ADS)

    Pessemier, W.; Raskin, G.; Prins, S.; Saey, P.; Merges, F.; Padilla, J. P.; Van Winckel, H.; Waelkens, C.

    2010-07-01

    A new control system is currently being developed for the 1.2-meter Mercator Telescope at the Roque de Los Muchachos Observatory (La Palma, Spain). Formerly based on transputers, the new Mercator Observatory Control System (MOCS) consists of a small network of Linux computers complemented by a central industrial controller and an industrial real-time data communication network. Python is chosen as the high-level language to develop flexible yet powerful supervisory control and data acquisition (SCADA) software for the Linux computers. Specialized applications such as detector control, auto-guiding and middleware management are also integrated in the same Python software package. The industrial controller, on the other hand, is connected to the majority of the field devices and is targeted to run various control loops, some of which are real-time critical. Independently of the Linux distributed control system (DCS), this controller makes sure that high priority tasks such as the telescope motion, mirror support and hydrostatic bearing control are carried out in a reliable and safe way. A comparison is made between different controller technologies including a LabVIEW embedded system, a PROFINET Programmable Logic Controller (PLC) and motion controller, and an EtherCAT embedded PC (soft-PLC). As the latter is chosen as the primary platform for the lower level control, a substantial part of the software is being ported to the IEC 61131-3 standard programming languages. Additionally, obsolete hardware is gradually being replaced by standard industrial alternatives with fast EtherCAT communication. The use of Python as a scripting language allows a smooth migration to the final MOCS: finished parts of the new control system can readily be commissioned to replace the corresponding transputer units of the old control system with minimal downtime. In this contribution, we give an overview of the systems design, implementation details and the current status of the project.

  13. Networked gamma radiation detection system for tactical deployment

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, Sanjoy; Maurer, Richard; Wolff, Ronald; Smith, Ethan; Guss, Paul; Mitchell, Stephen

    2015-08-01

    A networked gamma radiation detection system with directional sensitivity and energy spectral data acquisition capability is being developed by the National Security Technologies, LLC, Remote Sensing Laboratory to support the close and intense tactical engagement of law enforcement who carry out counterterrorism missions. In the proposed design, three clusters of 2″ × 4″ × 16″ sodium iodide crystals (4 each) with digiBASE-E (for list mode data collection) would be placed on the passenger side of a minivan. To enhance localization and facilitate rapid identification of isotopes, advanced smart real-time localization and radioisotope identification algorithms like WAVRAD (wavelet-assisted variance reduction for anomaly detection) and NSCRAD (nuisance-rejection spectral comparison ratio anomaly detection) will be incorporated. We will test a collection of algorithms and analysis that centers on the problem of radiation detection with a distributed sensor network. We will study the basic characteristics of a radiation sensor network and focus on the trade-offs between false positive alarm rates, true positive alarm rates, and time to detect multiple radiation sources in a large area. Empirical and simulation analyses of critical system parameters, such as number of sensors, sensor placement, and sensor response functions, will be examined. This networked system will provide an integrated radiation detection architecture and framework with (i) a large nationally recognized search database equivalent that would help generate a common operational picture in a major radiological crisis; (ii) a robust reach back connectivity for search data to be evaluated by home teams; and, finally, (iii) a possibility of integrating search data from multi-agency responders.

  14. Augmenting Trust Establishment in Dynamic Systems with Social Networks

    SciTech Connect

    Lagesse, Brent J; Kumar, Mohan; Venkatesh, Svetha; Lazarescu, Mihai

    2010-01-01

    Social networking has recently flourished in popularity through the use of social websites. Pervasive computing resources have allowed people stay well-connected to each other through access to social networking resources. We take the position that utilizing information produced by relationships within social networks can assist in the establishment of trust for other pervasive computing applications. Furthermore, we describe how such a system can augment a sensor infrastructure used for event observation with information from mobile sensors (ie, mobile phones with cameras) controlled by potentially untrusted third parties. Pervasive computing systems are invisible systems, oriented around the user. As a result, many future pervasive systems are likely to include a social aspect to the system. The social communities that are developed in these systems can augment existing trust mechanisms with information about pre-trusted entities or entities to initially consider when beginning to establish trust. An example of such a system is the Collaborative Virtual Observation (CoVO) system fuses sensor information from disaparate sources in soft real-time to recreate a scene that provides observation of an event that has recently transpired. To accomplish this, CoVO must efficently access services whilst protecting the data from corruption from unknown remote nodes. CoVO combines dynamic service composition with virtual observation to utilize existing infrastructure with third party services available in the environment. Since these services are not under the control of the system, they may be unreliable or malicious. When an event of interest occurs, the given infrastructure (bus cameras, etc.) may not sufficiently cover the necessary information (be it in space, time, or sensor type). To enhance observation of the event, infrastructure is augmented with information from sensors in the environment that the infrastructure does not control. These sensors may be unreliable

  15. The Study on the Communication Network of Wide Area Measurement System in Electricity Grid

    NASA Astrophysics Data System (ADS)

    Xiaorong, Cheng; Ying, Wang; Yangdan, Ni

    Wide area measurement system(WAMS) is a fundamental part of security defense in Smart Grid, and the communication system of WAMS is an important part of Electric power communication network. For a large regional network is concerned, the real-time data which is transferred in the communication network of WAMS will affect the safe operation of the power grid directly. Therefore, WAMS raised higher requirements for real-time, reliability and security to its communication network. In this paper, the architecture of WASM communication network was studied according to the seven layers model of the open systems interconnection(OSI), and the network architecture was researched from all levels. We explored the media of WAMS communication network, the network communication protocol and network technology. Finally, the delay of the network were analyzed.

  16. Integrated Microtransducer and Neural Networks System for Distributed Control

    DTIC Science & Technology

    1997-12-01

    this burden, to Washington Head 0< 5 a \\ ved -0188 cisting data sources, other aspect of this iu neports, 1215 Jefferson L.UHGI.UUII u uiMi uu...Network Systems for Distributed Control 6. AUTHOR(S) Professor Chih-Ming Ho 5 . FUNDING NUMBERS F49620-93-1-0332 7. PERFORMING ORGANIZATION NAME(S...Waltham, Mass. U.S.A. April, 1995. 5 . Joshi, Speyer, J. and Kim, J. "A systems theory approach to the control of transitional flows", Accept by J. of

  17. Event-triggered output feedback control for distributed networked systems.

    PubMed

    Mahmoud, Magdi S; Sabih, Muhammad; Elshafei, Moustafa

    2016-01-01

    This paper addresses the problem of output-feedback communication and control with event-triggered framework in the context of distributed networked control systems. The design problem of the event-triggered output-feedback control is proposed as a linear matrix inequality (LMI) feasibility problem. The scheme is developed for the distributed system where only partial states are available. In this scheme, a subsystem uses local observers and share its information to its neighbors only when the subsystem's local error exceeds a specified threshold. The developed method is illustrated by using a coupled cart example from the literature.

  18. Single-mode fiber systems for deep space communication network

    NASA Technical Reports Server (NTRS)

    Lutes, G.

    1982-01-01

    The present investigation is concerned with the development of single-mode optical fiber distribution systems. It is pointed out that single-mode fibers represent potentially a superior medium for the distribution of frequency and timing reference signals and wideband (400 MHz) IF signals. In this connection, single-mode fibers have the potential to improve the capability and precision of NASA's Deep Space Network (DSN). Attention is given to problems related to precise time synchronization throughout the DSN, questions regarding the selection of a transmission medium, and the function of the distribution systems, taking into account specific improvements possible by an employment of single-mode fibers.

  19. New elastomeric silicone based networks applicable as electroactive systems

    NASA Astrophysics Data System (ADS)

    Bejenariu, Anca G.; Boll, Mads; Lotz, Mikkel R.; Vraa, Christoffer; Skov, Anne L.

    2011-04-01

    Commercial elastomer materials are available for dielectric electroactive polymer (DEAP) purposes but the applied commercial elastomers have not been developed with the specific application in mind. It is therefore obvious that optimization of the elastomer material should be possible. In this study we focus on optimization of the mechanical properties of the elastomer and show that it is possible to lower the elastic modulus and still not compromise the other required mechanical properties such as fast response, stability, low degree of viscous dissipation and high extensibility. The elastomers are prepared from a vinyl-terminated polydimethyl siloxane (PDMS) and a 4-functional crosslinker by a platinum-catalyzed hydrosilylation reaction between the two reactants. Traditionally, elastomers based on hydrosilylation are prepared via a 'one-step two-pot' procedure (with a mix A and a mix B mixed in a given ratio). An alternative network formulation method is adopted in this study in order to obtain an elastomeric system with controlled topology - a so-called bimodal network. Bimodal networks are synthesized using a 'two-step four-pot' mixing procedure which results in a nonhomogeneous network structure which is shown to lead to novel mechanical properties due to the low extensibility of the short chains and the high extensibility of the long chains. The first ensures stability and the last retards the rupture process thereby combining two desired properties for DEAP purposes without necessarily compromising the viscous dissipation. Several elastomers are prepared and tested for the linear viscoelastic behaviour, i.e. behaviour in the small-strain limit (up to approximately 10% strain). The bimodal networks are, however, capable of extensions up to several times their initial length but the focus here is the small-strain limit.

  20. Neural Network Target Identification System for False Alarm Reduction

    NASA Technical Reports Server (NTRS)

    Ye, David; Edens, Weston; Lu, Thomas T.; Chao, Tien-Hsin

    2009-01-01

    A multi-stage automated target recognition (ATR) system has been designed to perform computer vision tasks with adequate proficiency in mimicking human vision. The system is able to detect, identify, and track targets of interest. Potential regions of interest (ROIs) are first identified by the detection stage using an Optimum Trade-off Maximum Average Correlation Height (OT-MACH) filter combined with a wavelet transform. False positives are then eliminated by the verification stage using feature extraction methods in conjunction with neural networks. Feature extraction transforms the ROIs using filtering and binning algorithms to create feature vectors. A feed forward back propagation neural network (NN) is then trained to classify each feature vector and remove false positives. This paper discusses the test of the system performance and parameter optimizations process which adapts the system to various targets and datasets. The test results show that the system was successful in substantially reducing the false positive rate when tested on a sonar image dataset.

  1. Lightning location system supervising Swedish power transmission network

    NASA Technical Reports Server (NTRS)

    Melin, Stefan A.

    1991-01-01

    For electric utilities, the ability to prevent or minimize lightning damage on personnel and power systems is of great importance. Therefore, the Swedish State Power Board, has been using data since 1983 from a nationwide lightning location system (LLS) for accurately locating lightning ground strikes. Lightning data is distributed and presented on color graphic displays at regional power network control centers as well as at the national power system control center for optimal data use. The main objectives for use of LLS data are: supervising the power system for optimal and safe use of the transmission and generating capacity during periods of thunderstorms; warning service to maintenance and service crews at power line and substations to end operations hazardous when lightning; rapid positioning of emergency crews to locate network damage at areas of detected lightning; and post analysis of power outages and transmission faults in relation to lightning, using archived lightning data for determination of appropriate design and insulation levels of equipment. Staff have found LLS data useful and economically justified since the availability of power system has increased as well as level of personnel safety.

  2. Privacy Management and Networked PPD Systems - Challenges Solutions.

    PubMed

    Ruotsalainen, Pekka; Pharow, Peter; Petersen, Francoise

    2015-01-01

    Modern personal portable health devices (PPDs) become increasingly part of a larger, inhomogeneous information system. Information collected by sensors are stored and processed in global clouds. Services are often free of charge, but at the same time service providers' business model is based on the disclosure of users' intimate health information. Health data processed in PPD networks is not regulated by health care specific legislation. In PPD networks, there is no guarantee that stakeholders share same ethical principles with the user. Often service providers have own security and privacy policies and they rarely offer to the user possibilities to define own, or adapt existing privacy policies. This all raises huge ethical and privacy concerns. In this paper, the authors have analyzed privacy challenges in PPD networks from users' viewpoint using system modeling method and propose the principle "Personal Health Data under Personal Control" must generally be accepted at global level. Among possible implementation of this principle, the authors propose encryption, computer understandable privacy policies, and privacy labels or trust based privacy management methods. The latter can be realized using infrastructural trust calculation and monitoring service. A first step is to require the protection of personal health information and the principle proposed being internationally mandatory. This requires both regulatory and standardization activities, and the availability of open and certified software application which all service providers can implement. One of those applications should be the independent Trust verifier.

  3. Network Performance Measurements for NASA's Earth Observation System

    NASA Technical Reports Server (NTRS)

    Loiacono, Joe; Gormain, Andy; Smith, Jeff

    2004-01-01

    NASA's Earth Observation System (EOS) Project studies all aspects of planet Earth from space, including climate change, and ocean, ice, land, and vegetation characteristics. It consists of about 20 satellite missions over a period of about a decade. Extensive collaboration is used, both with other US. agencies (e.g., National Oceanic and Atmospheric Administration (NOA), United States Geological Survey (USGS), Department of Defense (DoD), and international agencies (e.g., European Space Agency (ESA), Japan Aerospace Exploration Agency (JAXA)), to improve cost effectiveness and obtain otherwise unavailable data. Scientific researchers are located at research institutions worldwide, primarily government research facilities and research universities. The EOS project makes extensive use of networks to support data acquisition, data production, and data distribution. Many of these functions impose requirements on the networks, including throughput and availability. In order to verify that these requirements are being met, and be pro-active in recognizing problems, NASA conducts on-going performance measurements. The purpose of this paper is to examine techniques used by NASA to measure the performance of the networks used by EOSDIS (EOS Data and Information System) and to indicate how this performance information is used.

  4. Advanced information processing system: Authentication protocols for network communication

    NASA Technical Reports Server (NTRS)

    Harper, Richard E.; Adams, Stuart J.; Babikyan, Carol A.; Butler, Bryan P.; Clark, Anne L.; Lala, Jaynarayan H.

    1994-01-01

    In safety critical I/O and intercomputer communication networks, reliable message transmission is an important concern. Difficulties of communication and fault identification in networks arise primarily because the sender of a transmission cannot be identified with certainty, an intermediate node can corrupt a message without certainty of detection, and a babbling node cannot be identified and silenced without lengthy diagnosis and reconfiguration . Authentication protocols use digital signature techniques to verify the authenticity of messages with high probability. Such protocols appear to provide an efficient solution to many of these problems. The objective of this program is to develop, demonstrate, and evaluate intercomputer communication architectures which employ authentication. As a context for the evaluation, the authentication protocol-based communication concept was demonstrated under this program by hosting a real-time flight critical guidance, navigation and control algorithm on a distributed, heterogeneous, mixed redundancy system of workstations and embedded fault-tolerant computers.

  5. Network of fully integrated multispecialty hospital imaging systems

    NASA Astrophysics Data System (ADS)

    Dayhoff, Ruth E.; Kuzmak, Peter M.

    1994-05-01

    The Department of Veterans Affairs (VA) DHCP Imaging System records clinically significant diagnostic images selected by medical specialists in a variety of departments, including radiology, cardiology, gastroenterology, pathology, dermatology, hematology, surgery, podiatry, dental clinic, and emergency room. These images are displayed on workstations located throughout a medical center. All images are managed by the VA's hospital information system, allowing integrated displays of text and image data across medical specialties. Clinicians can view screens of `thumbnail' images for all studies or procedures performed on a selected patient. Two VA medical centers currently have DHCP Imaging Systems installed, and others are planned. All VA medical centers and other VA facilities are connected by a wide area packet-switched network. The VA's electronic mail software has been modified to allow inclusion of binary data such as images in addition to the traditional text data. Testing of this multimedia electronic mail system is underway for medical teleconsultation.

  6. Neural network-based systems for handprint OCR applications.

    PubMed

    Ganis, M D; Wilson, C L; Blue, J L

    1998-01-01

    Over the last five years or so, neural network (NN)-based approaches have been steadily gaining performance and popularity for a wide range of optical character recognition (OCR) problems, from isolated digit recognition to handprint recognition. We present an NN classification scheme based on an enhanced multilayer perceptron (MLP) and describe an end-to-end system for form-based handprint OCR applications designed by the National Institute of Standards and Technology (NIST) Visual Image Processing Group. The enhancements to the MLP are based on (i) neuron activations functions that reduce the occurrences of singular Jacobians; (ii) successive regularization to constrain the volume of the weight space; and (iii) Boltzmann pruning to constrain the dimension of the weight space. Performance characterization studies of NN systems evaluated at the first OCR systems conference and the NIST form-based handprint recognition system are also summarized.

  7. Neural Network Control of a Magnetically Suspended Rotor System

    NASA Technical Reports Server (NTRS)

    Choi, Benjamin B.

    1998-01-01

    Magnetic bearings offer significant advantages because they do not come into contact with other parts during operation, which can reduce maintenance. Higher speeds, no friction, no lubrication, weight reduction, precise position control, and active damping make them far superior to conventional contact bearings. However, there are technical barriers that limit the application of this technology in industry. One of them is the need for a nonlinear controller that can overcome the system nonlinearity and uncertainty inherent in magnetic bearings. At the NASA Lewis Research Center, a neural network was selected as a nonlinear controller because it generates a neural model without any detailed information regarding the internal working of the magnetic bearing system. It can be used even for systems that are too complex for an accurate system model to be derived. A feed-forward architecture with a back-propagation learning algorithm was selected because of its proven performance, accuracy, and relatively easy implementation.

  8. Remote network control plasma diagnostic system for Tokamak T-10

    NASA Astrophysics Data System (ADS)

    Troynov, V. I.; Zimin, A. M.; Krupin, V. A.; Notkin, G. E.; Nurgaliev, M. R.

    2016-09-01

    The parameters of molecular plasma in closed magnetic trap is studied in this paper. Using the system of molecular diagnostics, which was designed by the authors on the «Tokamak T-10» facility, the radiation of hydrogen isotopes at the plasma edge is investigated. The scheme of optical radiation registration within visible spectrum is described. For visualization, identification and processing of registered molecular spectra a new software is developed using MatLab environment. The software also includes electronic atlas of electronic-vibrational-rotational transitions for molecules of protium and deuterium. To register radiation from limiter cross-section a network control system is designed using the means of the Internet/Intranet. Remote control system diagram and methods are given. The examples of web-interfaces for working out equipment control scenarios and viewing of results are provided. After test run in Intranet, the remote diagnostic system will be accessible through Internet.

  9. A Partially Distributed Intrusion Detection System for Wireless Sensor Networks

    PubMed Central

    Cho, Eung Jun; Hong, Choong Seon; Lee, Sungwon; Jeon, Seokhee

    2013-01-01

    The increasing use of wireless sensor networks, which normally comprise several very small sensor nodes, makes their security an increasingly important issue. They can be practically and efficiently secured using intrusion detection systems. Conventional security mechanisms are not usually applicable due to the sensor nodes having limitations of computational power, memory capacity, and battery power. Therefore, specific security systems should be designed to function under constraints of energy or memory. A partially distributed intrusion detection system with low memory and power demands is proposed here. It employs a Bloom filter, which allows reduced signature code size. Multiple Bloom filters can be combined to reduce the signature code for each Bloom filter array. The mechanism could then cope with potential denial of service attacks, unlike many previous detection systems with Bloom filters. The mechanism was evaluated and validated through analysis and simulation.

  10. Neural Network and Fuzzy Logic Technology for Naval Flight Control Systems

    DTIC Science & Technology

    1991-08-06

    it is still uncertain what neural network and fuzzy logic functions are both technologically feasible and suitable for flight control system...this program is focused on the development of a neural network FCS design tool, a neural network flight control law emulator, a fuzzy logic automatic...carrier landing system and a neural network flight control configuration management system. For each project, some initial results are given. Also

  11. Optimization-based Approach to Cross-layer Resource Management in Wireless Networked Control Systems

    DTIC Science & Technology

    2013-05-01

    distribution is unlimited. Optimization-based approach to cross-layer resource management in Wireless networked control systems The views, opinions...Box 12211 Research Triangle Park, NC 27709-2211 cross-layer resource management , sampling rate adaptation, networked control system REPORT...7749 2 ABSTRACT Optimization-based approach to cross-layer resource management in Wireless networked control systems Report Title Wireless Networked

  12. A system's view of metro and regional optical networks

    NASA Astrophysics Data System (ADS)

    Lam, Cedric F.; Way, Winston I.

    2009-01-01

    Developments in fiber optic communications have been rejuvenated after the glut of the overcapacity at the turn of the century. The boom of video-centric network applications finally resulted in another wave of vast build-outs of broadband access networks such as FTTH, DOCSIS 3.0 and WI-FI systems, which in turn also drove up the bandwidth demands in metro and regional WDM networks. These new developments have rekindled research interests on technologies not only to meet the surging demand, but also to upgrade legacy network infrastructures in an evolutionary manner without disrupting existing services and incurring significant capital penalties. Standard bodies such as IEEE, ITU and OIF have formed task forces to ratify 100Gb/s interface standards. Thanks to the seemingly unlimited bandwidth in single-mode fibers, advances in optical networks has traditionally been fueled by more capable physical components such as more powerful laser, cleaner and wider bandwidth optical amplifier, faster modulator and photo-detectors, etc. In the meanwhile, the mainstream modulation technique for fiber optic communication systems has remained the most rudimentary form of on-off keying (OOK) and direct power detection for a very long period of time because spectral efficiency had never been a concern. This scenario, however, is no longer valid as demand for bandwidth is pushing the limit of current of current WDM technologies. In terms of spectral use, all the 100-GHz ITU grids in the C-band have been populated with 10Gb/s wavelengths in most of the WDM transport networks, and we are exhausting the power and bandwidth offered on existing fiber plant EDFAs. Beyond 10Gb/s, increasing the transmission to 40Gb/s by brute force OOK approach incurs significant penalties due to chromatic and polarization mode dispersion. With conventional modulation schemes, transmission impairments at 40Gb/s speed and above already become such difficult challenges that the efforts to manage these

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

    PubMed

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

    2015-03-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  15. Fuzzy neural network technique for system state forecasting.

    PubMed

    Li, Dezhi; Wang, Wilson; Ismail, Fathy

    2013-10-01

    In many system state forecasting applications, the prediction is performed based on multiple datasets, each corresponding to a distinct system condition. The traditional methods dealing with multiple datasets (e.g., vector autoregressive moving average models and neural networks) have some shortcomings, such as limited modeling capability and opaque reasoning operations. To tackle these problems, a novel fuzzy neural network (FNN) is proposed in this paper to effectively extract information from multiple datasets, so as to improve forecasting accuracy. The proposed predictor consists of both autoregressive (AR) nodes modeling and nonlinear nodes modeling; AR models/nodes are used to capture the linear correlation of the datasets, and the nonlinear correlation of the datasets are modeled with nonlinear neuron nodes. A novel particle swarm technique [i.e., Laplace particle swarm (LPS) method] is proposed to facilitate parameters estimation of the predictor and improve modeling accuracy. The effectiveness of the developed FNN predictor and the associated LPS method is verified by a series of tests related to Mackey-Glass data forecast, exchange rate data prediction, and gear system prognosis. Test results show that the developed FNN predictor and the LPS method can capture the dynamics of multiple datasets effectively and track system characteristics accurately.

  16. Early distinction system of mine fire in underground by using a neural-network system

    SciTech Connect

    Ohga, Kotaro; Higuchi, Kiyoshi

    1996-12-31

    In our laboratory, a new detection system using smell detectors was developed to detect the spontaneous combustion of coal and the combustion of other materials used underground. The results of experiments clearly the combustion of materials can be detected earlier by this detection system than by conventional detectors for gas and smoke, and there were significant differences between output data from each smell detector for coal, rubber, oil and wood. In order to discern the source of combustion gases, we have been developing a distinction system using a neural-network system. It has shown successful results in laboratory tests. This paper describes our detection system using smell detectors and our distinction system which uses a neural-network system, and presents results of experiments using both systems.

  17. Node-weighted interacting network measures improve the representation of real-world complex systems

    NASA Astrophysics Data System (ADS)

    Wiedermann, M.; Donges, J. F.; Heitzig, J.; Kurths, J.

    2013-04-01

    Many real-world complex systems are adequately represented by networks of interacting or interdependent networks. Additionally, it is often reasonable to take into account node weights such as surface area in climate networks, volume in brain networks, or economic capacity in trade networks to reflect the varying size or importance of subsystems. Combining both ideas, we derive a novel class of statistical measures for analysing the structure of networks of interacting networks with heterogeneous node weights. Using a prototypical spatial network model, we show that the newly introduced node-weighted interacting network measures provide an improved representation of the underlying system's properties as compared to their unweighted analogues. We apply our method to study the complex network structure of cross-boundary trade between European Union (EU) and non-EU countries finding that it provides relevant information on trade balance and economic robustness.

  18. Coherent Frequency Reference System for the NASA Deep Space Network

    NASA Technical Reports Server (NTRS)

    Tucker, Blake C.; Lauf, John E.; Hamell, Robert L.; Gonzaler, Jorge, Jr.; Diener, William A.; Tjoelker, Robert L.

    2010-01-01

    The NASA Deep Space Network (DSN) requires state-of-the-art frequency references that are derived and distributed from very stable atomic frequency standards. A new Frequency Reference System (FRS) and Frequency Reference Distribution System (FRD) have been developed, which together replace the previous Coherent Reference Generator System (CRG). The FRS and FRD each provide new capabilities that significantly improve operability and reliability. The FRS allows for selection and switching between frequency standards, a flywheel capability (to avoid interruptions when switching frequency standards), and a frequency synthesis system (to generate standardized 5-, 10-, and 100-MHz reference signals). The FRS is powered by redundant, specially filtered, and sustainable power systems and includes a monitor and control capability for station operations to interact and control the frequency-standard selection process. The FRD receives the standardized 5-, 10-, and 100-MHz reference signals and distributes signals to distribution amplifiers in a fan out fashion to dozens of DSN users that require the highly stable reference signals. The FRD is also powered by redundant, specially filtered, and sustainable power systems. The new DSN Frequency Distribution System, which consists of the FRS and FRD systems described here, is central to all operational activities of the NASA DSN. The frequency generation and distribution system provides ultra-stable, coherent, and very low phase-noise references at 5, l0, and 100 MHz to between 60 and 100 separate users at each Deep Space Communications Complex.

  19. The Construction of Higher Education Entrepreneur Services Network System a Research Based on Ecological Systems Theory

    NASA Astrophysics Data System (ADS)

    Xue, Jingxin

    The article aims to completely, systematically and objectively analyze the current situation of Entrepreneurship Education in China with Ecological Systems Theory. From this perspective, the author discusses the structure, function and its basic features of higher education entrepreneur services network system, and puts forward the opinion that every entrepreneurship organization in higher education institution does not limited to only one platform. Different functional supporting platforms should be combined closed through composite functional organization to form an integrated network system, in which each unit would impels others' development.

  20. Sensory System for Implementing a Human—Computer Interface Based on Electrooculography

    PubMed Central

    Barea, Rafael; Boquete, Luciano; Rodriguez-Ascariz, Jose Manuel; Ortega, Sergio; López, Elena

    2011-01-01

    This paper describes a sensory system for implementing a human–computer interface based on electrooculography. An acquisition system captures electrooculograms and transmits them via the ZigBee protocol. The data acquired are analysed in real time using a microcontroller-based platform running the Linux operating system. The continuous wavelet transform and neural network are used to process and analyse the signals to obtain highly reliable results in real time. To enhance system usability, the graphical interface is projected onto special eyewear, which is also used to position the signal-capturing electrodes. PMID:22346579

  1. Sensory system for implementing a human-computer interface based on electrooculography.

    PubMed

    Barea, Rafael; Boquete, Luciano; Rodriguez-Ascariz, Jose Manuel; Ortega, Sergio; López, Elena

    2011-01-01

    This paper describes a sensory system for implementing a human-computer interface based on electrooculography. An acquisition system captures electrooculograms and transmits them via the ZigBee protocol. The data acquired are analysed in real time using a microcontroller-based platform running the Linux operating system. The continuous wavelet transform and neural network are used to process and analyse the signals to obtain highly reliable results in real time. To enhance system usability, the graphical interface is projected onto special eyewear, which is also used to position the signal-capturing electrodes.

  2. Network Flow Simulation of Fluid Transients in Rocket Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Bandyopadhyay, Alak; Hamill, Brian; Ramachandran, Narayanan; Majumdar, Alok

    2011-01-01

    Fluid transients, also known as water hammer, can have a significant impact on the design and operation of both spacecraft and launch vehicle propulsion systems. These transients often occur at system activation and shutdown. The pressure rise due to sudden opening and closing of valves of propulsion feed lines can cause serious damage during activation and shutdown of propulsion systems. During activation (valve opening) and shutdown (valve closing), pressure surges must be predicted accurately to ensure structural integrity of the propulsion system fluid network. In the current work, a network flow simulation software (Generalized Fluid System Simulation Program) based on Finite Volume Method has been used to predict the pressure surges in the feed line due to both valve closing and valve opening using two separate geometrical configurations. The valve opening pressure surge results are compared with experimental data available in the literature and the numerical results compared very well within reasonable accuracy (< 5%) for a wide range of inlet-to-initial pressure ratios. A Fast Fourier Transform is preformed on the pressure oscillations to predict the various modal frequencies of the pressure wave. The shutdown problem, i.e. valve closing problem, the simulation results are compared with the results of Method of Characteristics. Most rocket engines experience a longitudinal acceleration, known as "pogo" during the later stage of engine burn. In the shutdown example problem, an accumulator has been used in the feed system to demonstrate the "pogo" mitigation effects in the feed system of propellant. The simulation results using GFSSP compared very well with the results of Method of Characteristics.

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

    DOEpatents

    Weigle, Eric H.

    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.

  4. A PC parallel port button box provides millisecond response time accuracy under Linux.

    PubMed

    Stewart, Neil

    2006-02-01

    For psychologists, it is sometimes necessary to measure people's reaction times to the nearest millisecond. This article describes how to use the PC parallel port to receive signals from a button box to achieve millisecond response time accuracy. The workings of the parallel port, the corresponding port addresses, and a simple Linux program for controlling the port are described. A test of the speed and reliability of button box signal detection is reported. If the reader is moderately familiar with Linux, this article should provide sufficient instruction for him or her to build and test his or her own parallel port button box. This article also describes how the parallel port could be used to control an external apparatus.

  5. Embedded Real-Time Linux for Instrument Control and Data Logging

    NASA Technical Reports Server (NTRS)

    Clanton, Sam; Gore, Warren J. (Technical Monitor)

    2002-01-01

    When I moved to the west. coast to take a job at NASA's Ames Research Center in Mountain View, CA, I was impressed with the variety of equipment and software which scientists at the center use to conduct their research. was happy to find that I was just as likely to see a machine running Lenox as one running Windows in the offices and laboratories of NASA Ames (although many people seem to use Moos around here). I was especially happy to find that the particular group with whom I was going to work, the Atmospheric Physics Branch at Ames, relied almost entirely on Lenox machines for their day-to-day work. So it was no surprise that when it was time to construct a new control system for one of their most important pieces of hardware, a switch from an unpredictable DOS-based platform to an Embedded Linux-based one was a decision easily made. The system I am working on is called the Solar Spectral Flux Radiometer (SSFR), a PC-104 based system custom-built by Dr. Warren Gore at Ames. Dr. Gore, Dr. Peter Pilewskie, Dr. Maura Robberies and Larry Pezzolo use the SSFR in their research. The team working on the controller project consists of Dr. Gore, John Pommier, and myself. The SSFR is used by the ,cities Atmospheric Radiation Group to measure solar spectral irradiance at moderate resolution to determine the radiative effect of clouds, aerosols, and gases on climate, and also to infer the physical properties of aerosols and clouds. Two identical SSFR's have been built and successfully deployed in three field missions: 1) the Department of Energy Atmospheric Radiation Measurement (ARM) Enhanced Shortwave Experiment (ARESE) II in February/March, 2000; 2) the Puerto Rico Dust Experiment (PRIDE) in July, 2000; and 3) the South African Regional Science Initiative (SAFARI) in August/September, 2000. Additionally, the SSFR was used to acquire water vapor spectra using the Ames Diameter base-path multiple-reflection absorption cell in a laboratory experiment.

  6. A distributed name resolution system in information centric networks

    NASA Astrophysics Data System (ADS)

    Elbreiki, Walid; Arlimatti, Shivaleela; Hassan, Suhaidi; Habbal, Adib; Elshaikh, Mohamed

    2016-08-01

    Information Centric Networks (ICN) is the new paradigm that envisages to shift the Internet away from its existing Point-to-Point architecture to a data centric, where communication is based on named hosts rather than the information stored on these hosts. Name Resolution is the center of attraction for ICN, where Named Data Objects (NDO) are used for identifying the information and guiding for routing or forwarding inside ICN. Recently, several researches use distributed NRS to overcome the problem of interest flooding, congestion and overloading. Yet the distribution of NRS is based on random distribution. How to distribute the NRS is still an important and challenging problem. In this work, we address the problem of distribution of NRS by proposing a new mechanism called Distributed Name Resolution System (DNRS), by considering the time of publishing the NDOs in the NRS. This mechanism partitions the network to distribute the workload among NRSs by increasing storage capacity. In addition, partitioning the network increases flexibility and scalability of NRS. We evaluate the effectiveness of our proposed mechanism, which achieves lesser end-to-end delay with more average throughputs compared to random distribution of NRS without disturbing the underlying routing or forwarding strategies.

  7. Neural network application to aircraft control system design

    NASA Technical Reports Server (NTRS)

    Troudet, Terry; Garg, Sanjay; Merrill, Walter C.

    1991-01-01

    The feasibility of using artificial neural networks as control systems for modern, complex aerospace vehicles is investigated via an example aircraft control design study. The problem considered is that of designing a controller for an integrated airframe/propulsion longitudinal dynamics model of a modern fighter aircraft to provide independent control of pitch rate and airspeed responses to pilot command inputs. An explicit model following controller using H infinity control design techniques is first designed to gain insight into the control problem as well as to provide a baseline for evaluation of the neurocontroller. Using the model of the desired dynamics as a command generator, a multilayer feedforward neural network is trained to control the vehicle model within the physical limitations of the actuator dynamics. This is achieved by minimizing an objective function which is a weighted sum of tracking errors and control input commands and rates. To gain insight in the neurocontrol, linearized representations of the nonlinear neurocontroller are analyzed along a commanded trajectory. Linear robustness analysis tools are then applied to the linearized neurocontroller models and to the baseline H infinity based controller. Future areas of research are identified to enhance the practical applicability of neural networks to flight control design.

  8. genepop'007: a complete re-implementation of the genepop software for Windows and Linux.

    PubMed

    Rousset, François

    2008-01-01

    This note summarizes developments of the genepop software since its first description in 1995, and in particular those new to version 4.0: an extended input format, several estimators of neighbourhood size under isolation by distance, new estimators and confidence intervals for null allele frequency, and less important extensions to previous options. genepop now runs under Linux as well as under Windows, and can be entirely controlled by batch calls.

  9. A network-based ranking system for US college football

    NASA Astrophysics Data System (ADS)

    Park, Juyong; Newman, M. E. J.

    2005-10-01

    American college football faces a conflict created by the desire to stage national championship games between the best teams of a season when there is no conventional play-off system for deciding which those teams are. Instead, ranking of teams is based on their records of wins and losses during the season, but each team plays only a small fraction of eligible opponents, making the system underdetermined or contradictory or both. It is an interesting challenge to create a ranking system that at once is mathematically well founded, gives results in general accord with received wisdom concerning the relative strengths of the teams, and is based upon intuitive principles, allowing it to be accepted readily by fans and experts alike. Here we introduce a one-parameter ranking method that satisfies all of these requirements and is based on a network representation of college football schedules.

  10. Networked Observation of Precipitating Cloud Systems in Oklahoma

    NASA Astrophysics Data System (ADS)

    Collis, S. M.; Giangrande, S. E.; Bharadwaj, N.

    2012-12-01

    Radars are inherently limited in their ability to resolve fine structure of cloud systems and completely image a volume of space. Both the radial nature of sampling and the issues of beam width mean that upper level features are often missed or poorly resolved. While constant azimuth scans (RHIs) give amazing insight into the vertical structure they are not capable of sampling full storm structure in within a time commensurate with the evolution of the storm system. This presentation will show results from the ARM multi-scale remote sensing facility in Lamont, Oklahoma where there is a network of three X-Band and a C-Band radar deployed. Taking care in quality control and using a flexible mapping methodology enables the combining of information from multiple sources. We will showcase some sample storm reconstructions highlighting the advantages of using the full capabilities of the observing system.

  11. Incomplete fuzzy data processing systems using artificial neural network

    NASA Technical Reports Server (NTRS)

    Patyra, Marek J.

    1992-01-01

    In this paper, the implementation of a fuzzy data processing system using an artificial neural network (ANN) is discussed. The binary representation of fuzzy data is assumed, where the universe of discourse is decartelized into n equal intervals. The value of a membership function is represented by a binary number. It is proposed that incomplete fuzzy data processing be performed in two stages. The first stage performs the 'retrieval' of incomplete fuzzy data, and the second stage performs the desired operation on the retrieval data. The method of incomplete fuzzy data retrieval is proposed based on the linear approximation of missing values of the membership function. The ANN implementation of the proposed system is presented. The system was computationally verified and showed a relatively small total error.

  12. Data Acquisition System for Russian Arctic Magnetometer Network

    NASA Astrophysics Data System (ADS)

    Janzhura, A.; Troshichev, O. A.; Takahashi, K.

    2010-12-01

    Monitoring of magnetic activity in the auroral zone is very essential for space weather problem. The big part of northern auroral zone lies in the Russian sector of Arctica. The Russian auroral zone stations are located far from the proper infrastructure and communications, and getting the data from the stations is complicated and nontrivial task. To resolve this problem a new acquisition system for magnetometers was implemented and developed in last few years, with the magnetic data transmission in real time that is important for many forecasting purpose. The system, based on microprocessor modules, is very reliable in hush climatic conditions. The information from the magnetic sensors transmits to AARI data center by satellite communication system and is presented at AARI web pages. This equipment upgrading of Russian polar magnetometer network is supported by the international RapidMag program.

  13. Synchronization of networked Jahn-Teller systems in SQUIDs

    NASA Astrophysics Data System (ADS)

    Gül, Yusuf

    2016-06-01

    We consider the nonlinear effects in a Jahn-Teller (JT) system of two coupled resonators interacting simultaneously with a flux qubit using coupled SQUIDs. A two-frequency description of JT system that inherits the networked structure of both nonlinear Josephson junctions and harmonic oscillators is employed to describe the synchronous structures in a multifrequency scheme. Eigenvalue spectrum is used to show the switch between the effective single mode and two mode configuration in terms of frequency difference. The Rabi supersplitting is investigated by the spectral response of JT systems in different coupling regimes. Second-order coherence functions are employed to investigate antibunching effects in resonator mode. Synchronous structure between correlations of privileged mode and qubit is obtained in localization-delocalization and photon blockade regime controlled by the population imbalance.

  14. Cooperative Development of the Pakistan Seismic Network System (PSNS)

    NASA Astrophysics Data System (ADS)

    Detweiler, S.; Mooney, W.; McDonald, S.

    2005-12-01

    We propose to cooperate with the Pakistan Meteorological Department for the design and construction of the new Pakistan Seismic Network System (PSNS) that has been funded by the government of Pakistan. The PSNS will consist of 12-15 broadband stations, 50 short-period stations, and 50 accelerometers. Our role will be to provide technical assistance in site selection, to prepare the Request for Proposals (RFP) from industry, and to evaluate performance. The relative importance of tsunami warnings, national earthquake and landslide hazards, and whether a largely urban or truly national network is envisioned will be determined early in the program. Final placement of stations will take many factors into consideration including proximity to faults and seismic activity, geographic accessibility, the consistency of bedrock, and various cultural or social effects. This cooperation has the potential to lead to the development of a desperately needed tsunami early warning network that could protect the Pakistani coastal population in the event of a natural disaster such as the Dec. 26, 2004 Sumatra earthquake and tsunami. The seismic hazard off the coast of Pakistan is high due to the proximity of the Makran and Sumatra subduction zones, the former of which could trigger tsunamis in Pakistan with heights of 12m within minutes. In addition to monitoring earthquake activity, the PSNS will provide seismic data of interest to the world-wide scientific community for a region in which there is little understanding of the upper crust and mantle. It will furthermore address educational outreach and diplomacy issues by providing training to Pakistani scientists in routine network operation and data processing.

  15. Operating systems for wireless sensor networks: a survey.

    PubMed

    Farooq, Muhammad Omer; Kunz, Thomas

    2011-01-01

    This paper presents a survey on the current state-of-the-art in Wireless Sensor Network (WSN) Operating Systems (OSs). In recent years, WSNs have received tremendous attention in the research community, with applications in battlefields, industrial process monitoring, home automation, and environmental monitoring, to name but a few. A WSN is a highly dynamic network because nodes die due to severe environmental conditions and battery power depletion. Furthermore, a WSN is composed of miniaturized motes equipped with scarce resources e.g., limited memory and computational abilities. WSNs invariably operate in an unattended mode and in many scenarios it is impossible to replace sensor motes after deployment, therefore a fundamental objective is to optimize the sensor motes' life time. These characteristics of WSNs impose additional challenges on OS design for WSN, and consequently, OS design for WSN deviates from traditional OS design. The purpose of this survey is to highlight major concerns pertaining to OS design in WSNs and to point out strengths and weaknesses of contemporary OSs for WSNs, keeping in mind the requirements of emerging WSN applications. The state-of-the-art in operating systems for WSNs has been examined in terms of the OS Architecture, Programming Model, Scheduling, Memory Management and Protection, Communication Protocols, Resource Sharing, Support for Real-Time Applications, and additional features. These features are surveyed for both real-time and non-real-time WSN operating systems.

  16. Remote Environmental Monitoring With a Wireless Sensor Network System

    NASA Astrophysics Data System (ADS)

    Kizito, F.; Hopmans, J. W.; Bales, R.; Tuli, A.; Kamai, T.

    2007-12-01

    Wireless sensors have the potential to reveal dynamic environmental variables in remote landscapes at reduced long-term costs and offer a promising approach to revolutionize environmental monitoring. Better management of surface water in remote landscapes warrants close monitoring of moisture and temperature variability. This work describes field data demonstrating the functionality of a deployed wireless network system, consisting of various soil moisture sensors. Soil water potential sensors with an imbedded thermistor were deployed in a remote meadow along a topographic gradient with dense tree canopies in Wolverton Meadows in Sequoia National Park. The sensors responded to moisture and temperature variations and the wireless system met the goal of providing informative data on dynamic responses of soil moisture to rainfall and snowmelt. The deployed sensor system functioned well during harsh winter conditions at 7000 feet, requiring low power. The study highlights measurement accuracy limitations and presents an alternative, robust wireless Zigbee sensor network, using Crossbow motes. We demonstrate that deployment, implementation and long-term field monitoring in remote and challenging environments is possible with current technologies.

  17. Statistically validated network of portfolio overlaps and systemic risk

    PubMed Central

    Gualdi, Stanislao; Cimini, Giulio; Primicerio, Kevin; Di Clemente, Riccardo; Challet, Damien

    2016-01-01

    Common asset holding by financial institutions (portfolio overlap) is nowadays regarded as an important channel for financial contagion with the potential to trigger fire sales and severe losses at the systemic level. We propose a method to assess the statistical significance of the overlap between heterogeneously diversified portfolios, which we use to build a validated network of financial institutions where links indicate potential contagion channels. The method is implemented on a historical database of institutional holdings ranging from 1999 to the end of 2013, but can be applied to any bipartite network. We find that the proportion of validated links (i.e. of significant overlaps) increased steadily before the 2007–2008 financial crisis and reached a maximum when the crisis occurred. We argue that the nature of this measure implies that systemic risk from fire sales liquidation was maximal at that time. After a sharp drop in 2008, systemic risk resumed its growth in 2009, with a notable acceleration in 2013. We finally show that market trends tend to be amplified in the portfolios identified by the algorithm, such that it is possible to have an informative signal about institutions that are about to suffer (enjoy) the most significant losses (gains). PMID:28000764

  18. Operating Systems for Wireless Sensor Networks: A Survey

    PubMed Central

    Farooq, Muhammad Omer; Kunz, Thomas

    2011-01-01

    This paper presents a survey on the current state-of-the-art in Wireless Sensor Network (WSN) Operating Systems (OSs). In recent years, WSNs have received tremendous attention in the research community, with applications in battlefields, industrial process monitoring, home automation, and environmental monitoring, to name but a few. A WSN is a highly dynamic network because nodes die due to severe environmental conditions and battery power depletion. Furthermore, a WSN is composed of miniaturized motes equipped with scarce resources e.g., limited memory and computational abilities. WSNs invariably operate in an unattended mode and in many scenarios it is impossible to replace sensor motes after deployment, therefore a fundamental objective is to optimize the sensor motes’ life time. These characteristics of WSNs impose additional challenges on OS design for WSN, and consequently, OS design for WSN deviates from traditional OS design. The purpose of this survey is to highlight major concerns pertaining to OS design in WSNs and to point out strengths and weaknesses of contemporary OSs for WSNs, keeping in mind the requirements of emerging WSN applications. The state-of-the-art in operating systems for WSNs has been examined in terms of the OS Architecture, Programming Model, Scheduling, Memory Management and Protection, Communication Protocols, Resource Sharing, Support for Real-Time Applications, and additional features. These features are surveyed for both real-time and non-real-time WSN operating systems. PMID:22163934

  19. Statistically validated network of portfolio overlaps and systemic risk.

    PubMed

    Gualdi, Stanislao; Cimini, Giulio; Primicerio, Kevin; Di Clemente, Riccardo; Challet, Damien

    2016-12-21

    Common asset holding by financial institutions (portfolio overlap) is nowadays regarded as an important channel for financial contagion with the potential to trigger fire sales and severe losses at the systemic level. We propose a method to assess the statistical significance of the overlap between heterogeneously diversified portfolios, which we use to build a validated network of financial institutions where links indicate potential contagion channels. The method is implemented on a historical database of institutional holdings ranging from 1999 to the end of 2013, but can be applied to any bipartite network. We find that the proportion of validated links (i.e. of significant overlaps) increased steadily before the 2007-2008 financial crisis and reached a maximum when the crisis occurred. We argue that the nature of this measure implies that systemic risk from fire sales liquidation was maximal at that time. After a sharp drop in 2008, systemic risk resumed its growth in 2009, with a notable acceleration in 2013. We finally show that market trends tend to be amplified in the portfolios identified by the algorithm, such that it is possible to have an informative signal about institutions that are about to suffer (enjoy) the most significant losses (gains).

  20. Adaptive conventional power system stabilizer based on artificial neural network

    SciTech Connect

    Kothari, M.L.; Segal, R.; Ghodki, B.K.

    1995-12-31

    This paper deals with an artificial neural network (ANN) based adaptive conventional power system stabilizer (PSS). The ANN comprises an input layer, a hidden layer and an output layer. The input vector to the ANN comprises real power (P) and reactive power (Q), while the output vector comprises optimum PSS parameters. A systematic approach for generating training set covering wide range of operating conditions, is presented. The ANN has been trained using back-propagation training algorithm. Investigations reveal that the dynamic performance of ANN based adaptive conventional PSS is quite insensitive to wide variations in loading conditions.