4,110 research outputs found

    Hot Swapping Protocol Implementations in the OPNET Modeler Development Environment

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    This research effort demonstrates hot swapping protocol implementations in OPNET via the building of a dependency injection testing framework. The thesis demonstrates the externalization (compiling as stand-alone code) of OPNET process models, and their inclusion into custom DLL\u27s (Dynamically Linked Libraries). A framework then utilizes these process model DLL\u27s, to specify, or “inject,” process implementations post-compile time into an OPNET simulation. Two separate applications demonstrate this mechanism. The first application is a toolkit that allows for the testing of multiple routing related protocols in various combinations without code re-compilation or scenario re-generation. The toolkit produced similar results as the same simulation generated manually with OPNET. The second application demonstrates the viability of a unit testing mechanism for the externalized process models. The unit testing mechanism was demonstrated by integrating with CxxTest and executing xUnit style test suits

    DIVERSE: a Software Toolkit to Integrate Distributed Simulations with Heterogeneous Virtual Environments

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    We present DIVERSE (Device Independent Virtual Environments- Reconfigurable, Scalable, Extensible), which is a modular collection of complimentary software packages that we have developed to facilitate the creation of distributed operator-in-the-loop simulations. In DIVERSE we introduce a novel implementation of remote shared memory (distributed shared memory) that uses Internet Protocol (IP) networks. We also introduce a new method that automatically extends hardware drivers (not in the operating system kernel driver sense) into inter-process and Internet hardware services. Using DIVERSE, a program can display in a CAVE™, ImmersaDesk™, head mounted display (HMD), desktop or laptop without modification. We have developed a method of configuring user programs at run-time by loading dynamic shared objects (DSOs), in contrast to the more common practice of creating interpreted configuration languages. We find that by loading DSOs the development time, complexity and size of DIVERSE and DIVERSE user applications is significantly reduced. Configurations to support different I/O devices, device emulators, visual displays, and any component of a user application including interaction techniques, can be changed at run-time by loading different sets of DIVERSE DSOs. In addition, interpreted run-time configuration parsers have been implemented using DIVERSE DSOs; new ones can be created as needed. DIVERSE is free software, licensed under the terms of the GNU General Public License (GPL) and the GNU Lesser General Public License (LGPL) licenses. We describe the DIVERSE architecture and demonstrate how DIVERSE was used in the development of a specific application, an operator-in-the-loop Navy ship-board crane simulator, which runs unmodified on a desktop computer and/or in a CAVE with motion base motion queuing

    A Framework for Datatype Transformation

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    We study one dimension in program evolution, namely the evolution of the datatype declarations in a program. To this end, a suite of basic transformation operators is designed. We cover structure-preserving refactorings, but also structure-extending and -reducing adaptations. Both the object programs that are subject to datatype transformations, and the meta programs that encode datatype transformations are functional programs.Comment: Minor revision; now accepted at LDTA 200

    dReDBox: Materializing a full-stack rack-scale system prototype of a next-generation disaggregated datacenter

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    Current datacenters are based on server machines, whose mainboard and hardware components form the baseline, monolithic building block that the rest of the system software, middleware and application stack are built upon. This leads to the following limitations: (a) resource proportionality of a multi-tray system is bounded by the basic building block (mainboard), (b) resource allocation to processes or virtual machines (VMs) is bounded by the available resources within the boundary of the mainboard, leading to spare resource fragmentation and inefficiencies, and (c) upgrades must be applied to each and every server even when only a specific component needs to be upgraded. The dRedBox project (Disaggregated Recursive Datacentre-in-a-Box) addresses the above limitations, and proposes the next generation, low-power, across form-factor datacenters, departing from the paradigm of the mainboard-as-a-unit and enabling the creation of function-block-as-a-unit. Hardware-level disaggregation and software-defined wiring of resources is supported by a full-fledged Type-1 hypervisor that can execute commodity virtual machines, which communicate over a low-latency and high-throughput software-defined optical network. To evaluate its novel approach, dRedBox will demonstrate application execution in the domains of network functions virtualization, infrastructure analytics, and real-time video surveillance.This work has been supported in part by EU H2020 ICTproject dRedBox, contract #687632.Peer ReviewedPostprint (author's final draft

    Multiple Heat Exchangers Simulation Within the Newton-Raphson Framework

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    A general framework is proposed for simulating complex heat exchanger geometries in a manner suitable for sequential solution of the refrigerant- and air-side equations for mass, momentum and energy. The sequential solution enables the algorithm to be applied to a single module of a complex heat exchanger, and then integrated with other modules within a simultaneous equation solver employing a Newton-Raphson approach. This report also describes the integration of component subroutines into system simulation models for air conditioners and refrigerators. The modular approach is illustrated by describing its application to a dual-evaporator refrigerator simulation.Air Conditioning and Refrigeration Project 6

    Modeling and Control of Battery Management Systems with High-Frequency AC Link Coupled Multiport Series Resonant Converters for 2nd Life Battery Applications

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    While the use and production of Electric Vehicles becomes more prevalent, it is also important to make this economical and ensure the reduction of a carbon footprint. Second-life batteries can satisfy both problems as batteries can be used in a second-life application for lower power purposes such as supplementing the grid so the infrastructure needed to charge the expanding fleet of Electric Vehicles can be easily supplied. This thesis goes through the process of Active Cell Balancing which will produce equal capacities, or similar batteries, that can be more efficiently used in these and other types of second-life applications. The process is expanded through series connection of the converters and modules of batteries so the process can be used for up to 96 Nissan Cells at a time. This project at Utah State University will also entail the removal and replacement of these Nissan battery cells while running to ensure quick but smooth balancing of hundreds of batteries
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