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Computer and Systems Architecture

2011

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Full-Text Articles in Computer Engineering

Productivity Evaluation Of Self-Adaptive Software Model Driven Architecture, Basel Magableh Sep 2011

Productivity Evaluation Of Self-Adaptive Software Model Driven Architecture, Basel Magableh

Articles

Anticipating context changes using a model-based approach requires a formal procedure for analysing and modelling context-dependent functionality and stable description of the architecture which supports dynamic decision-making and architecture evolution. This article demonstrates the capabilities of the context-oriented component-based application-model-driven architecture (COCA-MDA) to support the development of self- adaptive applications; the authors describe a state-of-the-art case study and evaluate the development effort involved in adopting the COCA-MDA in constructing the application. An intensive analysis of the applica- tion requirements simplified the process of modelling the application’s behavioural model; therefore, instead of modelling several variation models, the developers modelled an extra-functionality …


Software Development Approach For Discrete Simulators, Grzegorz Chmaj, Dawid Maksymilian Zydek Aug 2011

Software Development Approach For Discrete Simulators, Grzegorz Chmaj, Dawid Maksymilian Zydek

Electrical & Computer Engineering Faculty Research

Simulation is the most common approach to perform the problem research. Among several types of simulation, the most common way is the discrete simulation, which assumes the division of the time scale into fixed length time slots. Depending on investigated problem, simulation packages may be used or it could be necessary to design and create own simulation system. In this paper, we propose the complete pre-study scheme and the most commonly appearing implementation problems with suggested solutions. We also describe how to implement the exemplary simulator in C++.


Calibration Of Complex System Dynamics Models: A Practioner's Report, Rod Walker, Wayne Wakeland Jul 2011

Calibration Of Complex System Dynamics Models: A Practioner's Report, Rod Walker, Wayne Wakeland

Systems Science Faculty Publications and Presentations

This paper is not a typical academic paper that is solidly grounded in the literature. Instead, this paper reports practitioner’s experiences in rebuilding and calibrating a very large system dynamics model. A prior version of this model had been in use for over 10 years in an ongoing executive training simulation. That model had never worked correctly in several key areas, requiring the outputs to be manually adjusted by very experienced facilitators during the course of the simulation. The present project rebuilt the system dynamics model, redesigned the parts that weren’t working, and calibrated the resulting model to match the …


A System Dynamics Model Of Pharmaceutical Opioids: Medical Use, Diversion, And Nonmedical Use, Teresa Schmidt, Wayne Wakeland, J. David Haddox Jul 2011

A System Dynamics Model Of Pharmaceutical Opioids: Medical Use, Diversion, And Nonmedical Use, Teresa Schmidt, Wayne Wakeland, J. David Haddox

Systems Science Faculty Publications and Presentations

A dramatic rise in the nonmedical of pharmaceutical opioids has presented the United States with a substantial public health problem. Nonmedical use of prescription pain relievers has become increasingly prevalent in the US over the last two decades, and diversion of medicines obtained by prescription is assumed to be a major source of supply for nonmedical opioid use. Policymakers striving to protect population health by ameliorating the adverse outcomes of nonmedical use of opioid analgesics could benefit from a systems-level model which reflects the complexity of the system and incorporates the full range of available data. To address this need, …


A Hybrid Agent Architecture Integrating Desire, Intention And Reinforcement Learning, Ah-Hwee Tan, Yew-Soon Ong, Akejariyawong Tapanuj Jul 2011

A Hybrid Agent Architecture Integrating Desire, Intention And Reinforcement Learning, Ah-Hwee Tan, Yew-Soon Ong, Akejariyawong Tapanuj

Research Collection School Of Computing and Information Systems

This paper presents a hybrid agent architecture that integrates the behaviours of BDI agents, specifically desire and intention, with a neural network based reinforcement learner known as Temporal DifferenceFusion Architecture for Learning and COgNition (TD-FALCON). With the explicit maintenance of goals, the agent performs reinforcement learning with the awareness of its objectives instead of relying on external reinforcement signals. More importantly, the intention module equips the hybrid architecture with deliberative planning capabilities, enabling the agent to purposefully maintain an agenda of actions to perform and reducing the need of constantly sensing the environment. Through reinforcement learning, plans can also be …


Measuring Design Metrics In Websites, Emilio Navarro, Ronan Fitzpatrick Jun 2011

Measuring Design Metrics In Websites, Emilio Navarro, Ronan Fitzpatrick

Conference papers

The current state of the World Wide Web demands website designs that engage consumers in order to allow them to consume services or generate leads to maximize revenue. This paper describes a software quality factor to measure the success of websites by analyzing web design structure and not relying only on websites traffic data. It is also documents the requirements and architecture to build a software tool that measures criteria for determining Engagibility. A new set of social criteria to be measured for current website philosophy is also proposed.


Design And Implementation Of A Byzantine Fault Tolerance Framework For Non-Deterministic Applications, H. Zhang, Wenbing Zhao, Louise E. Moser, P. Michael Melliar-Smith Jun 2011

Design And Implementation Of A Byzantine Fault Tolerance Framework For Non-Deterministic Applications, H. Zhang, Wenbing Zhao, Louise E. Moser, P. Michael Melliar-Smith

Electrical and Computer Engineering Faculty Publications

State-machine-based replication is an effective way to increase the availability and dependability of mission-critical applications. However, all practical applications contain some degree of non-determinism. Consequently, ensuring strong replica consistency in the presence of application non-determinism has been one of the biggest challenges in building dependable distributed systems. In this Study, the authors propose a classification of common types of application non-determinism with respect to the requirement of achieving Byzantine fault tolerance (BFT), and present the design and implementation of a BFT framework that controls these types of non-determinism in a systematic manner.


Resizable, Scalable, Concurrent Hash Tables, Josh Triplett, Paul E. Mckenney, Jonathan Walpole Jun 2011

Resizable, Scalable, Concurrent Hash Tables, Josh Triplett, Paul E. Mckenney, Jonathan Walpole

Computer Science Faculty Publications and Presentations

We present algorithms for shrinking and expanding a hash table while allowing concurrent, wait-free, linearly scalable lookups. These resize algorithms allow the hash table to maintain constant-time performance as the number of entries grows, and reclaim memory as the number of entries decreases, without delaying or disrupting readers.

We implemented our algorithms in the Linux kernel, to test their performance and scalability. Benchmarks show lookup scalability improved 125x over readerwriter locking, and 56% over the current state-of-the-art for Linux, with no performance degradation for lookups during a resize.

To achieve this performance, this hash table implementation uses a new concurrent …


Resizable, Scalable, Concurrent Hash Tables Via Relativistic Programming, Josh Triplett, Paul E. Mckenney, Jonathan Walpole Jun 2011

Resizable, Scalable, Concurrent Hash Tables Via Relativistic Programming, Josh Triplett, Paul E. Mckenney, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Presentation focusing on software synchronization, thread locking, transactional memory, and relativistic programming. Hash table algorithms are presented with examples of relativistic list insertion and removal, and related data structures. Existing approaches are compared to new methodologies and future work with relativistic data structures.


Efficient Support Of Consistent Cyclic Search With Read-Copy-Update And Parallel Updates, Jonathan Walpole, Paul E. Mckenney May 2011

Efficient Support Of Consistent Cyclic Search With Read-Copy-Update And Parallel Updates, Jonathan Walpole, Paul E. Mckenney

Computer Science Faculty Publications and Presentations

A method, system and computer program product for supporting concurrent updates to a shared data element group while preserving group integrity on behalf of one or more readers that are concurrently referencing group data elements without using locks or atomic instructions. Two or more updaters may be invoked to generate new group data elements. Each new data element created by the same up dater is assigned a new generation number that is different than a global generation number associated with the data element group and which allows a reader of the data element group to determine whether the new data …


Design And Performance Analysis Of Mac Schemes For Wireless Sensor Networks Powered By Ambient Energy Harvesting, Zhi Ang Eu, Hwee-Pink Tan, Winston K. G. Seah May 2011

Design And Performance Analysis Of Mac Schemes For Wireless Sensor Networks Powered By Ambient Energy Harvesting, Zhi Ang Eu, Hwee-Pink Tan, Winston K. G. Seah

Research Collection School Of Computing and Information Systems

Energy consumption is a perennial issue in the design of wireless sensor networks (WSNs) which typically rely on portable sources like batteries for power. Recent advances in ambient energy harvesting technology have made it a potential and promising alternative source of energy for powering WSNs. By using energy harvesters with supercapacitors, WSNs are able to operate perpetually until hardware failure and in places where batteries are hard or impossible to replace. In this paper, we study the performance of different medium access control (MAC) schemes based on CSMA and polling techniques for WSNs which are solely powered by ambient energy …


A Relativistic Enhancement To Software Transactional Memory, Philip William Howard, Jonathan Walpole May 2011

A Relativistic Enhancement To Software Transactional Memory, Philip William Howard, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Relativistic Programming is a technique that allows low overhead, linearly-scalable concurrent reads. It also allows joint access parallelism between readers and a writer. Unfortunately, it has so far been limited to a single writer so it does not scale on the write side. Software Transactional Memory (STM) is a technique that allows programs to take advantage of disjoint access parallelism on both the read-side and write-side. Unfortunately, STM systems have a higher overhead than many other synchronization mechanisms so although STM scales, STM starts from a lower baseline. We propose combining relativistic programming and software transactional memory in a way …


Reconfigurable Systems: A Potential Solution To The Von Neumann Bottleneck, Damian L. Miller Apr 2011

Reconfigurable Systems: A Potential Solution To The Von Neumann Bottleneck, Damian L. Miller

Senior Honors Theses

The difficulty of overcoming the disparity between processor speeds and data access speeds, a condition known as the von Neumann bottleneck, has been a source of consternation for computer hardware developers for many years. Although a number of temporary solutions have been proposed and implemented in modern machines, these solutions have only managed to treat the major symptoms, rather than solve the root problem. As the number of transistors on a chip roughly doubles every two years, the von Neumann bottleneck has continued to tighten in spite of these solutions, prompting some computer hardware professionals to advocate a paradigm shift …


A Cost-Benefit Analysis Of A Campus Computing Grid, Preston M. Smith Apr 2011

A Cost-Benefit Analysis Of A Campus Computing Grid, Preston M. Smith

Purdue Polytechnic Masters Theses

Any major research institution has a substantial number of computer systems on its campus, often in the scale of tens of thousands. Given that a large amount of scientific computing is appropriate for execution in an opportunistic environment, a campus grid is an inexpensive way to build a powerful computational resource. What is missing, though, is a model for making an informed decision on the cost-effectives of a campus grid. In this thesis, the author describes a model for measuring the costs and benefits of building a campus computing resource based on the institution’s existing investment in computing hardware.

For …


Interactivity-Constrained Server Provisioning In Large-Scale Distributed Virtual Environments, Nguyen Binh Duong Ta, Thang Nguyen, Suiping Zhou, Xueyan Tang, Wentong Cai, Rassul Ayani Apr 2011

Interactivity-Constrained Server Provisioning In Large-Scale Distributed Virtual Environments, Nguyen Binh Duong Ta, Thang Nguyen, Suiping Zhou, Xueyan Tang, Wentong Cai, Rassul Ayani

Research Collection School Of Computing and Information Systems

Maintaining interactivity is one of the key challenges in distributed virtual environments (DVE), e.g., online games, distributed simulations, etc., due to the large, heterogeneous Internet latencies; and the fact that clients in a DVE are usually geographically separated. In this paper, we consider a new problem, termed the interactivity-constrained server provisioning problem, whose goal is to minimize the number of distributed servers needed to achieve a pre-determined level of interactivity. We identify and formulate two variants of this new problem and show that they are both NP-hard via reductions to the set covering problem. We then propose several computationally efficient …


Cloud Computing: Architectural And Policy Implications, Christopher S. Yoo Apr 2011

Cloud Computing: Architectural And Policy Implications, Christopher S. Yoo

All Faculty Scholarship

Cloud computing has emerged as perhaps the hottest development in information technology. Despite all of the attention that it has garnered, existing analyses focus almost exclusively on the issues that surround data privacy without exploring cloud computing’s architectural and policy implications. This article offers an initial exploratory analysis in that direction. It begins by introducing key cloud computing concepts, such as service-oriented architectures, thin clients, and virtualization, and discusses the leading delivery models and deployment strategies that are being pursued by cloud computing providers. It next analyzes the economics of cloud computing in terms of reducing costs, transforming capital expenditures …


Propeller: A Scalable Metadata Organization For A Versatile Searchable File System, Lei Xu, Hong Jiang, Xue Liu, Lei Tian, Yu Hua, Jian Hu Mar 2011

Propeller: A Scalable Metadata Organization For A Versatile Searchable File System, Lei Xu, Hong Jiang, Xue Liu, Lei Tian, Yu Hua, Jian Hu

CSE Technical Reports

The exponentially increasing amount of data in file systems has made it increasingly important for users, administrators and applications to be able to fast retrieve files using file-search services, instead of replying on the standard file system API to traverse the hierarchical namespaces. The quality of the file-search services is significantly affected by the file-indexing overhead, the file-search performance and the accuracy of search results. Unfortunately, the existing file-search solutions either are so poorly scalable that their performance degrades unacceptably when the systems scale up, or incur so much crawling delays that they produce acceptably inaccurate results. We believe that …


Rough Consensus And Running Code: Integrating Engineering Principles Into Internet Policy Debates, Christopher S. Yoo Mar 2011

Rough Consensus And Running Code: Integrating Engineering Principles Into Internet Policy Debates, Christopher S. Yoo

All Faculty Scholarship

This is the introduction to a symposium issue for a conference designed to bring the engineering community, policymakers, legal academics, and industry participants together in an attempt to provide policymakers with a better understanding of the Internet’s technical aspects and to explore emerging issues of particular importance to current broadband policy.


Scalable Correct Memory Ordering Via Relativistic Programming, Josh Triplett, Philip William Howard, Paul E. Mckenney, Jonathan Walpole Mar 2011

Scalable Correct Memory Ordering Via Relativistic Programming, Josh Triplett, Philip William Howard, Paul E. Mckenney, Jonathan Walpole

Computer Science Faculty Publications and Presentations

We propose and document a new concurrent programming model, relativistic programming. This model allows readers to run concurrently with writers, without blocking or using expensive synchronization. Relativistic programming builds on existing synchronization primitives that allow writers to wait for current readers to finish with minimal reader overhead. Our methodology models data structures as graphs, and reader algorithms as traversals of these graphs; from this foundation we show how writers can implement arbitrarily strong ordering guarantees for the visibility of their writes, up to and including total ordering.


Generalized Construction Of Scalable Concurrent Data Structures Via Relativistic Programming, Josh Triplett, Paul E. Mckenney, Philip W. Howard, Jonathan Walpole Mar 2011

Generalized Construction Of Scalable Concurrent Data Structures Via Relativistic Programming, Josh Triplett, Paul E. Mckenney, Philip W. Howard, Jonathan Walpole

Computer Science Faculty Publications and Presentations

We present relativistic programming, a concurrent programming model based on shared addressing, which supports efficient, scalable operation on either uniform shared-memory or distributed shared- memory systems. Relativistic programming provides a strong causal ordering property, allowing a series of read operations to appear as an atomic transaction that occurs entirely between two ordered write operations. This preserves the simple immutable-memory programming model available via mutual exclusion or transactional memory. Furthermore, relativistic programming provides joint-access parallelism, allowing readers to run concurrently with a writer on the same data. We demonstrate a generalized construction technique for concurrent data structures based on relativistic programming, …


Interoperable Credentials Management For Wholesale Banking, Glenn Benson, Shiu-Kai Chin, Sean Croston, Karthick Jayaraman, Susan Older Feb 2011

Interoperable Credentials Management For Wholesale Banking, Glenn Benson, Shiu-Kai Chin, Sean Croston, Karthick Jayaraman, Susan Older

Electrical Engineering and Computer Science - All Scholarship

A gap exists between wholesale-banking business practices and security best practices: wholesale banks operate within the boundaries of contract law, while security best practices often relies upon a benevolent trusted party outside the scope of straightforward contracts. While some business domains may be able to bridge this gap, the ultra-high-value transactions used in business-to-business banking substantially increase the size of the gap. The gap becomes most apparent when regarded from the perspective of interoperability. If a single user applies the same credential to sign high-value transactions at multiple banks, then the trusted-party model becomes overly cumbersome and conflicts with an …


A Real Time Web Based Electronic Triage, Resource Allocation And Hospital Dispatch System For Emergency Response, Venkata Srihari Inampudi Jan 2011

A Real Time Web Based Electronic Triage, Resource Allocation And Hospital Dispatch System For Emergency Response, Venkata Srihari Inampudi

Masters Theses 1911 - February 2014

Disasters are characterized by large numbers of victims and required resources, overwhelming the available resources. Disaster response involves various entities like Incident Commanders, dispatch centers, emergency operations centers, area command and hospitals. An effective emergency response system should facilitate coordination between these various entities. Victim triage, emergency resource allocation and victim dispatch to hospitals form an important part of an emergency response system. In this present research effort, an emergency response system with the aforementioned components is developed.

Triage is the process of prioritizing mass casualty victims based on severity of injuries. The system presented in this thesis is a …


A Real Time Indoor Navigation And Monitoring System For Firefighters And Visually Impaired, Siddhesh R. Gandhi Jan 2011

A Real Time Indoor Navigation And Monitoring System For Firefighters And Visually Impaired, Siddhesh R. Gandhi

Masters Theses 1911 - February 2014

ABSTRACT

A REAL TIME INDOOR NAVIGATION AND MONITORING SYSTEM FOR FIREFIGHTERS AND VISUALLY IMPAIRED

MAY 2011

SIDDHESH RAJAN GANDHI

M.S. E.C.E, UNIVERSITY OF MASSACHUSETTS AMHERST

Directed by: Professor Aura Ganz

There has been a widespread growth of technology in almost every facet of day to day life. But there are still important application areas in which technology advancements have not been implemented in a cost effective and user friendly manner. Such applications which we will address in this proposal include: 1) indoor localization and navigation of firefighters during rescue operations and 2) indoor localization and navigation for the blind and …


Executable Architecture Research At Old Dominion University, Andreas Tolk, Johnny J. Garcia, Edwin A. Shuman Jan 2011

Executable Architecture Research At Old Dominion University, Andreas Tolk, Johnny J. Garcia, Edwin A. Shuman

Computational Modeling & Simulation Engineering Faculty Publications

Executable Architectures allow the evaluation of system architectures not only regarding their static, but also their dynamic behavior. However, the systems engineering community do not agree on a common formal specification of executable architectures. To close this gap and identify necessary elements of an executable architecture, a modeling language, and a modeling formalism is topic of ongoing PhD research. In addition, systems are generally defined and applied in an operational context to provide capabilities and enable missions. To maximize the benefits of executable architectures, a second PhD effort introduces the idea of creating an executable context in addition to the …


Enhancing Simulation Composability And Interoperability Using Conceptual/Semantic/Ontological Models, Andreas Tolk, John A. Miller Jan 2011

Enhancing Simulation Composability And Interoperability Using Conceptual/Semantic/Ontological Models, Andreas Tolk, John A. Miller

Computational Modeling & Simulation Engineering Faculty Publications

(First paragraph) Two emerging trends in Modeling and Simulation (M&S) are beginning to dovetail in a potentially highly productive manner, namely conceptual modeling and semantic modeling. Conceptual modeling has existed for several decades, but its importance has risen to the forefront in the last decade (Taylor and Robinson, 2006; Robinson, 2007). Also, during the last decade, progress on the Semantic Web has begun to influence M&S, with the development of general modeling ontologies (Miller et al, 2004), as well as ontologies for modeling particular domains (Durak, 2006). An ontology, which is a formal specification of a conceptualization (Gruber et al, …


Do We Need M&S Science?, Jose J. Padilla, Saikou Y. Diallo, Andreas Tolk Jan 2011

Do We Need M&S Science?, Jose J. Padilla, Saikou Y. Diallo, Andreas Tolk

VMASC Publications

No abstract provided.


Software Reuse For Modeling And Simulation, Emily Andrew, Charles D. Turnitsa, Andreas Tolk Jan 2011

Software Reuse For Modeling And Simulation, Emily Andrew, Charles D. Turnitsa, Andreas Tolk

Computational Modeling & Simulation Engineering Faculty Publications

In Modeling and Simulation, as a distinct area of software engineering, there is much interest in being able to reuse software components. However, the practice of simulation development and maintenance is different from software engineering because of several factors. In this paper, a brief overview of the foundations of interoperability, and how they apply to the reuse of model based software is explored, as well as examination of current practices to include M&S software repositories. Some recommendations, based on research at the Virginia Modeling Analysis and Simulation Center (VMASC) and practice at the Raytheon Company Network Centric Services, are made.


Ua3/9/2 I.T. Division Annual Report + Tactical Plan, Wku Information Technology Jan 2011

Ua3/9/2 I.T. Division Annual Report + Tactical Plan, Wku Information Technology

WKU Archives Records

Annual report of WKU Information Technology Division submitted to WKU President Gary Ransdell. Report is housed in UA3/9/2 Subject Files.


Technology Management Trends In Law Schools, Carol A. Watson, Larry Reeves Jan 2011

Technology Management Trends In Law Schools, Carol A. Watson, Larry Reeves

Articles, Chapters and Online Publications

Discusses the role of librarians in law school technology management and analyzes technology staffing survey results for 2002, 2006, and 2010. While survey results indicate a trend toward establishing separate information technology departments within law schools, librarians are and will continue to be actively involved in law school technology.


A New Approach To Algebraic Coding Theory Through The Applications Of Soft Sets, Florentin Smarandache, Mumtaz Ali Jan 2011

A New Approach To Algebraic Coding Theory Through The Applications Of Soft Sets, Florentin Smarandache, Mumtaz Ali

Branch Mathematics and Statistics Faculty and Staff Publications

Algebraic codes play a signifcant role in the minimisation of data corruption which caused by defects such as inference, noise channel, crosstalk, and packet loss. In this paper, we introduce soft codes (soft linear codes) through the application of soft sets which is an approximated collection of codes. We also discuss several types of soft codes such as type-1 soft codes, complete soft codes etc. Further, we construct the soft generator matrix and soft parity check matrix for the soft linear codes. Moreover, we develop two techniques for the decoding of soft codes.