1,387 research outputs found

    Demo: An Interoperability Development and Performance Diagnosis Environment

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    Interoperability is key to widespread adoption of sensor network technology, but interoperable systems have traditionally been difficult to develop and test. We demonstrate an interoperable system development and performance diagnosis environment in which different systems, different software, and different hardware can be simulated in a single network configuration. This allows both development, verification, and performance diagnosis of interoperable systems. Estimating the performance is important since even when systems interoperate, the performance can be sub-optimal, as shown in our companion paper that has been conditionally accepted for SenSys 2011

    Spartan Daily, May 19, 1959

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    Volume 46, Issue 129https://scholarworks.sjsu.edu/spartandaily/3908/thumbnail.jp

    Performability Evaluation of Voice Services in Converged Networks

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    In the last years, the transmission of voice services in converged networks has experienced a huge growth. However, there are still some questions considering the ability of these networks to deliver voice services with acceptable quality. In this paper, we applied analytical modeling and simulation to analyze the quality of voice services using a new index, called MOS a , which considers jointly the MOS index and the availability of the subjacent infrastructure. We consider the influence of different CODECs (G.711 and G.729), queuing policies (Priority Queuing and Custom Queuing), and the warm standby redundancy mechanism. Our goal is to analyze the quality of these services by taking into account overloading conditions in different  architectures/scenarios. These scenarios were constructed using the modeling mechanisms Reliability Block Diagram and Stochastic Petri Nets in addition to a discrete event simulator. Experimental results indicate that the G.711 CODEC has a higher sensitivity both in terms of data traffic volume and allocated network resources in relation to the G.729 CODEC

    NASA Tech Briefs, February 2009

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    Tech Briefs are short announcements of innovations originating from research and development activities of the National Aeronautics and Space Administration. They emphasize information considered likely to be transferable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. Topics covered include: Measuring Low Concentrations of Liquid Water in Soil; The Mars Science Laboratory Touchdown Test Facility; Non-Contact Measurement of Density and Thickness Variation in Dielectric Materials; Compact Microwave Fourier Spectrum Analyzer; InP Heterojunction Bipolar Transistor Amplifiers to 255 GHz; Combinatorial Generation of Test Suites; In-Phase Power-Combined Frequency Tripler at 300 GHz; Electronic System for Preventing Airport Runway Incursions; Smaller but Fully Functional Backshell for Cable Connector; Glove-Box or Desktop Virtual-Reality System; Composite Layer Manufacturing with Fewer Interruptions; Improved Photoresist Coating for Making CNT Field Emitters; A Simplified Diagnostic Method for Elastomer Bond Durability; Complex Multifunctional Polymer/Carbon-Nanotube Composites; Very High Output Thermoelectric Devices Based on ITO Nanocomposites; Reducing Unsteady Loads on a Piggyback Miniature Submarine; Ultrasonic/Sonic Anchor; Grooved Fuel Rings for Nuclear Thermal Rocket Engines; Pulsed Operation of an Ion Accelerator; Autonomous Instrument Placement for Mars Exploration Rovers; Mission and Assets Database; TCP/IP Interface for the Satellite Orbit Analysis Program (SOAP); Trajectory Calculator for Finite-Radius Cutter on a Lathe; Integrated System Health Management Development Toolkit

    A Demonstration Scenario for the NorNet Core Multi-Homed Network Testbed

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    There is extensive on-going research taking place with the goal of implementing transport layer protocols that are able to utilize multi-homing on machines (connection to multiple ISPs). Multi-homing has potential to improve resilience and increase total goodput compared to using a single connection. This would e.g. benefit the trend of more and more services being moved online and into the cloud. The NorNet Core multi-homed network testbed aims to facilitate this research by offering programmable virtual machines located at multiple different sites across the world, accessible for researchers. The aim of this project is the design and implementation of a demonstration platform for NorNet Core that enables the testbed to be illustratively demonstrated to potential new users. This is done by offering users interactive experiments, and geographical visualization of various communication scenarios between nodes in the NorNet Core network in real time. The demonstration platform puts emphasis on demonstrating the unique aspects of NorNet Core compared to other networking testbeds; namely the multi-homed nature and IPv6 support for all of the nodes. This thesis discusses the technical aspects of designing and implementing the platform, as well as demonstrating the finished result with various demonstration scenarios. The Qt programming framework was chosen as the primary development framework for this application

    Automatic conditioning of the LHC injection kickers

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    The LHC injection systems, located near the interaction regions 2 and 8, comprise 4 fast pulsed kicker magnets (MKI) per ring to bring the beam onto the orbit. Each magnet is housed in a separate vacuum tank. Their nominal operating voltage is 54 kV, and the nominal pulse length 7.86 µs. To prepare these magnets for operation they are once assembled and baked out, gradually subjected to higher and higher voltages and greater pulse lengths, until their voltage holding capability is sufficiently beyond the nominal operating conditions. In the past this "conditioning" was carried out manually, and thus a manpower-intensive, and also technically not optimal procedure. To overcome these drawbacks a program has been developed, running in a Programmable Logic Controller (PLC), which has been used to condition the full suite of LHC injection kickers automatically

    TCP/IP stack fingerprinting for patch detection in a distributed Windows environment

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    Patch Management has become important in every system administrator\u27s work profile. A missing patch can be essentially considered a vulnerability as the hackers make use of the knowledge of the vulnerability from the security bulletin and attempt attacks for that vulnerability. An efficient patch management solution is necessary to counter known vulnerabilities. For this an inventory listing of the patches installed in each system called a patch audit helps the system administrators know the patch status and install only the necessary patches. An important problem in patch auditing is that there may be many systems in a network for which the administrator does not have administrative privileges and hence cannot find the patch status. Current patch management tools do not address this problem.;This thesis investigates the possibility of finding patterns for missing patches by using TCP/IP Stack Fingerprinting. Malformed TCP packets are sent to the target system and the TCP and IP headers of the response from it are analyzed to find out specific patterns for a missing patch.;Windows based systems are the primary target since they typically constitute a majority of the systems in a network. They are as well, considered to be the most vulnerable. This investigation limits itself to classifying DCOM RPC Buffer overflow vulnerabilities on Windows based systems

    Ultrasonic Tension Controller for Web Tensioning

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    Indiana University Purdue University IndianapolisThe design of the Ultrasonic Tension Control package provides an industrial package to a previously vulnerable product. The previous design utilized a microcontroller which took analog feedback from an ultrasonic sensor to control brake pressure to a tensioning system to wind or unwind different products. The system still uses an ultrasonic sensor but uses a programmable logic controller (PLC) and variable frequency drive (VFD) to control the winding and unwinding speed. By using more industrial components, the system is more durable and resistant to shock, temperature, or other extreme environments. The introduction of a touch screen is also favorable and provides a convenient interface for operators to run the full process or troubleshooting to be done on a screen that puts the system into a manual mode. Future design considerations include putting the design into a smaller footprint for further cost reduction. Also the ability to automatically detect the type of variable frequency drive connected would be beneficial to prevent the user from incorrectly entering data.Electrical Engineering Technolog

    Vacuum Controls and Diagnostics

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    This paper describes the CERN's vacuum control system from the field devices to the Supervisory Control and Data Acquisition software. First, a particular attention is given to the environment present in the accelerators, like noise coupling and ionizing radiation, which can affect the quality of the measurements and the reliability of the system. Then, the main vacuum instruments and their associated conditioning circuits and controllers are presented, before to introduce the hardware interlock logic and alarms used for the vacuum system and the machine protection. Finally, the Supervisory Control and Data Acquisition software and its architecture are described, including data engineering and the main functionalities provided to the users for controls and diagnostics.Comment: 23 pages, contribution to the CAS - CERN Accelerator School: Vacuum for Particle Accelerators, 6-16 June 2017, Glumsl\"ov, Swede
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