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2015

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Articles 1411 - 1440 of 2105

Full-Text Articles in Computer Sciences

The Expression Problem, Gracefully, Andrew P. Black Jan 2015

The Expression Problem, Gracefully, Andrew P. Black

Computer Science Faculty Publications and Presentations

The “Expression Problem” was brought to prominence by Wadler in 1998. It is widely regarded as illustrating that the two mainstream approaches to data abstraction — procedural abstraction and type abstraction— are complementary, with the strengths of one being the weaknesses of the other. Despite an extensive literature, the origin of the problem remains ill-understood. I show that the core problem is in fact the use of global constants, and demonstrate that an important aspect of the problem goes away when Java is replaced by a language like Grace, which eliminates them.


The Grace Programming Language Draft Specification Version 0.5. 2025, Andrew P. Black, Kim B. Bruce, James Noble Jan 2015

The Grace Programming Language Draft Specification Version 0.5. 2025, Andrew P. Black, Kim B. Bruce, James Noble

Computer Science Faculty Publications and Presentations

This is a specification of the Grace Programming Language. This specification is notably incomplete, and everything is subject to change. For discussion and rationale, see http://gracelang.org.


Ear-Phone: A Context-Aware Noise Mapping Using Smart Phones, Rajib Rana, Chun Tung Chou, Nirupama Bulusu, Salil Kanhere, Wen Hu Jan 2015

Ear-Phone: A Context-Aware Noise Mapping Using Smart Phones, Rajib Rana, Chun Tung Chou, Nirupama Bulusu, Salil Kanhere, Wen Hu

Computer Science Faculty Publications and Presentations

A noise map facilitates the monitoring of environmental noise pollution in urban areas. It can raise citizen awareness of noise pollution levels, and aid in the development of mitigation strategies to cope with the adverse effects. However, state-of-the-art techniques for rendering noise maps in urban areas are expensive and rarely updated (for months or even years), as they rely on population and traffic models rather than on real data. Smart phone based urban sensing can be leveraged to create an open and inexpensive platform for rendering up-to-date noise maps. In this paper, we present the design, implementation and performance evaluation …


S-Store: Streaming Meets Transaction Processing, John Meehan, Nesime Tatbul, Cansu Aslantas, Ugur Cetintemel, Jiang Du, Tim Kraska, Samuel Madden, David Maier, Andrew Pavlo, Michael Stonebraker, Kristin A. Tufte, Hao Wang Jan 2015

S-Store: Streaming Meets Transaction Processing, John Meehan, Nesime Tatbul, Cansu Aslantas, Ugur Cetintemel, Jiang Du, Tim Kraska, Samuel Madden, David Maier, Andrew Pavlo, Michael Stonebraker, Kristin A. Tufte, Hao Wang

Computer Science Faculty Publications and Presentations

Stream processing addresses the needs of real-time applications. Transaction processing addresses the coordination and safety of short atomic computations. Heretofore, these two modes of operation existed in separate, stove-piped systems. In this work, we attempt to fuse the two computational paradigms in a single system called S-Store. In this way, S-Store can simultaneously accommodate OLTP and streaming applications. We present a simple transaction model for streams that integrates seamlessly with a traditional OLTP system. We chose to build S-Store as an extension of H-Store, an open-source, in-memory, distributed OLTP database system. By implementing S-Store in this way, we can make …


Desiderata For A Big Data Language, David Maier Jan 2015

Desiderata For A Big Data Language, David Maier

Computer Science Faculty Publications and Presentations

Data management and analytics systems for big data have proliferated, including column stores, array databases, graphanalysis environments and linear-algebra packages. This burgeoning of systems has lead to a surfeit of language and APIs. It is time to consider a new framework that can span these systems and simplify the programming and maintenance of Big Data applications. There are two key goals for such a framework:

Portability: It should be relatively easy to move an application or tool developed on one platform to operate against another. As a corollary, back-end data and analytics services should be swappable in a particular …


Generation And Validation Of Optimal Topologies For Solid Freeform Fabrication, Purnajyoti Bhaumik Jan 2015

Generation And Validation Of Optimal Topologies For Solid Freeform Fabrication, Purnajyoti Bhaumik

Masters Theses

"The study of fabricating topologically optimized parts is presented hereafter. The mapping of topology optimization results for Standard Tessellation Language (STL) writing would enable the solid freeform fabrication of lightweight mechanisms. Aerospace leaders such as NASA, Boeing, Airbus, European Aeronautic Defense And Space Company (EADS), and GE Aero invest in topology optimization research for the production of lightweight materials. Certain concepts such as microstructural homogenization, discretization, and mapping are reviewed and presented in the context of topology optimization. Future biomedical applications of solid freeform fabrication such as organ printing stand to save millions of lives through the robust development of …


Default Rules In Functional Logic Programs, Sergio Antoy, Michael Hanus Jan 2015

Default Rules In Functional Logic Programs, Sergio Antoy, Michael Hanus

Computer Science Faculty Publications and Presentations

In functional logic programs, rules are applicable independently of textual order, i.e., any rule can potentially be used to evaluate an expression. This is similar to logic languages and opposite to functional languages, e.g., Haskell enforces a strict sequential interpretation of rules. However, in some situations it is convenient to express alternatives by means of compact default rules. Although default rules are often used in functional programs, the non-deterministic nature of functional logic programs does not allow to directly transfer this concept from functional to functional logic languages in a meaningful way. In this paper we propose a new concept …


Usage Based Topology For Dcns, Qing Yi, Suresh Singh Jan 2015

Usage Based Topology For Dcns, Qing Yi, Suresh Singh

Computer Science Faculty Publications and Presentations

Many data center network topologies are designed to provide full bisection bandwidth for tens of thousands of servers in order to achieve high network throughput and server agility. However, the utilization rate of DCNs on average is below 10%, which results in a significant waste of network resources and energy. Many researchers propose consolidating network traffic flows to maximize the set of idle network equipment and switching them to low power mode to save energy. In this paper, we propose using skinnier network topologies to meet performance requirements of realistic loads thus saving not only energy but capital cost as …


Query From Examples: An Iterative, Data-Driven Approach To Query Construction, Hao Li, Chee-Yong Chan, David Maier Jan 2015

Query From Examples: An Iterative, Data-Driven Approach To Query Construction, Hao Li, Chee-Yong Chan, David Maier

Computer Science Faculty Publications and Presentations

In this paper, we propose a new approach, called Query from Examples (QFE), to help non-expert database users construct SQL queries. Our approach, which is designed for users who might be unfamiliar with SQL, only requires that the user is able to determine whether a given output table is the result of his or her intended query on a given input database. To kick-start the construction of a target query Q, the user first provides a pair of inputs: a sample database D and an output table R which is the result of Q on D. As there will be …


Two Compact Incremental Prime Sieves, Jonathan P. Sorenson Jan 2015

Two Compact Incremental Prime Sieves, Jonathan P. Sorenson

Scholarship and Professional Work - LAS

A prime sieve is an algorithm that finds the primes up to a bound n. We say that a prime sieve is incremental, if it can quickly determine if n+1 is prime after having found all primes up to n. We say a sieve is compact if it uses roughly √n space or less. In this paper, we present two new results.

  • We describe the rolling sieve, a practical, incremental prime sieve that takes O(n log log n) time and O(√n log n) bits of space.
  • We also …


Near-Optimal Online Multiselection In Internal And External Memory, Jonathan P. Sorenson, Jérémy Barbay, Ankur Gupta, S. Srinivasa Rao Jan 2015

Near-Optimal Online Multiselection In Internal And External Memory, Jonathan P. Sorenson, Jérémy Barbay, Ankur Gupta, S. Srinivasa Rao

Scholarship and Professional Work - LAS

We introduce an online version of the multiselection problem, in which q selection queries are requested on an unsorted array of n elements. We provide the first online algorithm that is 1-competitive with online algorithm proposed by Kaligosi et al.[ICALP 2005] in terms of comparison complexity. Our algorithm also supports online search queries efficiently.

We then extend our algorithm to the dynamic setting, while retaining online functionality, by supporting arbitrary insertions and deletions on the array. Assuming that the insertion of an element is immediately preceded by a search for that element, we show that our dynamic online algorithm performs …


Sparse Representation Based Classification: Towards Efficiency And Accuracy, Soheil Shafiee Jan 2015

Sparse Representation Based Classification: Towards Efficiency And Accuracy, Soheil Shafiee

Computer Science and Engineering Dissertations - Archive

With the fast growing deployment of machine intelligence in several real-life applications, there are always increasing needs for faster and more precise machine learning algorithms, especially classification and object recognition. One of the most recent methods proposed for this purpose is Sparse Representation-based Classification (SRC) which works based on the emerging theory of Compressive Sensing. SRC shows excellent classification results in comparison to many well-known classification approaches. However, despite its high recognition power, SRC suffers from high computational and memory costs as it directly uses all original ground truth data as representatives to build its training model. Given high recognition …


Design And Analysis Of Place-Based Opportunistic Networks, Yanliang Liu Jan 2015

Design And Analysis Of Place-Based Opportunistic Networks, Yanliang Liu

Computer Science and Engineering Dissertations - Archive

The swift growth and popularization of wireless technology and mobile smart phones have unfolded various opportunities and challenges before researchers' eyes. Opportunistic networks is one of the interesting and challenging topics. Generally speaking, opportunistic networks exploit the potential capability of existing mobile devices carried by people to provide pervasive computing service, such as data forwarding, without pre-planted infrastructures. The movement of mobile devices introduced by human activity plays a crucial role in the functionality of opportunistic networks, since it influences the contacts between different mobile devices. It is wellknown that human movement presents these place-centered features: intermittent hops between places …


Tools For Program Understanding And Reverse-Engineering Of Mobile Applications, Tuan Anh Nguyen Jan 2015

Tools For Program Understanding And Reverse-Engineering Of Mobile Applications, Tuan Anh Nguyen

Computer Science and Engineering Dissertations - Archive

Mobile software development is evolving rapidly. Software development includes computer programing, documenting, testing and bug fixing processes. These processes need a detail understanding of the application logic which often requires reverse-engineering their artifacts. My thesis identifies and addresses the following three problems in mobile software development, specifically in program understanding and reverse-engineering for mobile application development. (1) There is no graphical on-phone debugger. (2) The second problem is that mobile software programmers have to manually re-implement the conceptual screen drawings or sketches of graphical artists in code, which is cumbersome and expensive. (3) Companies try to “go mobile” (by developing …


Calculus For Decision Systems, Jorge Antonio Samayoa Ranero Jan 2015

Calculus For Decision Systems, Jorge Antonio Samayoa Ranero

Open Access Dissertations

The conceptualization of the term "system" has become highly dependent on the application domain. What a physicist means by the term system might be different than what a sociologist means by the same term. In 1956, Bertalanffy [1] defined a system as " a set of units with relationships among them". This and many other definitions of system share the idea of a system as a black box that has parts or elements interacting between each other. This means that at some level of abstraction all systems are similar, what eventually differentiates one system from another is the set of …


Smooth Subdivision Surfaces: Mesh Blending And Local Interpolation, Jianzhong Wang Jan 2015

Smooth Subdivision Surfaces: Mesh Blending And Local Interpolation, Jianzhong Wang

Theses and Dissertations--Computer Science

Subdivision surfaces are widely used in computer graphics and animation. Catmull-Clark subdivision (CCS) is one of the most popular subdivision schemes. It is capable of modeling and representing complex shape of arbitrary topology. Polar surface, working on a triangle-quad mixed mesh structure, is proposed to solve the inherent ripple problem of Catmull-Clark subdivision surface (CCSS).

CCSS is known to be C1 continuous at extraordinary points. In this work, we present a G2 scheme at CCS extraordinary points. The work is done by revising CCS subdivision step with Extraordinary-Points-Avoidance model together with mesh blending technique which selects guiding control …


A Comprehensive Analysis Of Computer Use Among African Americans, Kandice Lauren Smith Jan 2015

A Comprehensive Analysis Of Computer Use Among African Americans, Kandice Lauren Smith

Walden Dissertations and Doctoral Studies

On average, African Americans receive lower wages in the workplace due to lack of advanced technical skills. The reason for technical deficiency among some African Americans is often lack of exposure to IT resources at an early age. The purpose of this ethnographic study was to identify and explore the factors that contribute to lack of IT resources available to some African Americans to cultivate IT skills. Information literacy theory formed the conceptual framework, which focused on information resources that African American and Caucasians use in the workforce for problem solving and retrieving information. Data were collected by conducting face-to-face …


Distinguishing Leadership Of Information Assurance Teams, Bamidele Adetokunbo Bankole Jan 2015

Distinguishing Leadership Of Information Assurance Teams, Bamidele Adetokunbo Bankole

Walden Dissertations and Doctoral Studies

Information assurance (IA) projects are essential components of the information technology industry and often fail due to budget overruns, missed deadlines, and lack of performance by the project teams. The purpose of this phenomenological study was to explore the strategies necessary to improve IA project team performance. Lewin's situational leadership theory was used as the conceptual framework for this study. Interviews were conducted with 20 IA professionals located in the Washington, DC Metropolitan area. The data were transcribed, coded, and clustered for the identification of common patterns based on the Moustakas' modified van Kaam analysis. The major themes that emerged …


Regression Analysis Of Cloud Computing Adoption For U.S. Hospitals, Terence H. Lee Jan 2015

Regression Analysis Of Cloud Computing Adoption For U.S. Hospitals, Terence H. Lee

Walden Dissertations and Doctoral Studies

Industrial experts agree that cloud computing can significantly improve business and public access to low cost computing power and storage. Despite the benefits of cloud computing, recent research surveys indicated that its adoption in U.S. hospitals is slower than expected. The purpose of this study was to understand what factors influence cloud adoption in U.S. hospitals. The theoretical foundation of the research was the diffusion of innovations and technology-organization-environment framework. The research question was to examine the predictability of cloud computing adoption for U.S. hospitals as a function of 6 influential factors: relative advantage, compatibility, complexity, organizational size, structure, and …


Diffusion Of Electronic Health Records In Rural Primary Care Clinics, Patricia Lynn Mason Jan 2015

Diffusion Of Electronic Health Records In Rural Primary Care Clinics, Patricia Lynn Mason

Walden Dissertations and Doctoral Studies

By the end of 2015, Medicare-eligible physicians at primary care practices (PCP) who do not use an electronic health record (EHR) system will incur stiff penalties if they fail to meet the deadline for using EHRs. Yet, less than 30% of rural primary clinics have fully functional EHR systems. The purpose of this phenomenology study was to explore rural primary care physicians and physician assistants' experiences regarding overcoming barriers to implementing EHRs. Complex adaptive systems formed the conceptual framework for this study. Data were collected through face-to-face interviews with a purposeful sample of 21 physicians and physician assistants across 2 …


The Value Of Diagnostic Software And Doctors' Decision Making, Babatunde Ayodele Alaofin Jan 2015

The Value Of Diagnostic Software And Doctors' Decision Making, Babatunde Ayodele Alaofin

Walden Dissertations and Doctoral Studies

The prevalence of medical misdiagnosis has remained high despite the adoption of diagnostic software. This ongoing controversy about the role of technology in mitigating the problem of misdiagnosis centers on the question of whether diagnostic software does reduce the incidence of misdiagnosis if properly relied upon by physicians. The purpose of this quantitative, cross-sectional study based on planned behavior theory was to measure doctors' opinions of diagnostic technology's medical utility. Recruitment e-mails were sent to 3,100 AMA-accredited physicians through their database that yielded a sample of 99 physicians for the study. One-sample t tests and, where appropriate because of non-normal …


Exploring Government Contractor Experiences Assessing And Reporting Software Development Status, Putnam P. Texel Jan 2015

Exploring Government Contractor Experiences Assessing And Reporting Software Development Status, Putnam P. Texel

Walden Dissertations and Doctoral Studies

Reports from academic, commercial, and government organizations have documented software-intensive system cost and schedule overruns for decades. These reports have identified lack of management insight into the software development process as one of many contributing factors. Multiple management mechanisms exist. However, these mechanisms do not support the assessment, and subsequent reporting, of software completion status. Additionally, the conceptual framework, based on industry standards, is limited in its relevance to this study due to an emphasis on what is needed while deferring implementation details. The purpose of this phenomenological study was to explore U.S. government contractors' lived experiences of assessing and …


Exploring Knowledge Management Practices In Service-Based Small Business Enterprises, Orlando Skelton Jan 2015

Exploring Knowledge Management Practices In Service-Based Small Business Enterprises, Orlando Skelton

Walden Dissertations and Doctoral Studies

Small business enterprises (SBEs) are significant contributors to business growth and employment in the United States, but despite governmental support, the failure rate of SBEs is high. Some small business leaders lack the critical management skills to detect or discover when underperformance in revenue-generation is due to gaps in organizational knowledge or business practices associated with managing knowledge assets. Guided by the knowledge-based view of the firm, the purpose of this multiple case study was to address that gap by exploring the skills needed by leaders to understand how deficiencies in their knowledge management practices contribute to underperformance. Semistructured interview …


Nurses Knowledge, Skills, And Attitude Toward Electronic Health Records (Ehr), Sharon L. Adams Jan 2015

Nurses Knowledge, Skills, And Attitude Toward Electronic Health Records (Ehr), Sharon L. Adams

Walden Dissertations and Doctoral Studies

Information technology (IT) has been rapidly integrated into the healthcare industry, including nursing, and has the ability to reduce errors, cut cost, and enhance patient care. However, approximately 45% of the current nurse workforce lacks adequate training in computer skills, which may hinder the adoption of health-related IT in the workplace. Characteristics of Rogers's diffusion of innovation (relative advantage, compatibility, complexity, trialability, and observability) guided this project. This project was conducted to address the problem of IT adoption on a local level and was designed to assess whether simulation training on a generic electronic health record (EHR) system would improve …


Evaluating Success Factors In Implementing E-Maintenance In Maintenance, Repair, And Overhaul (Mro) Organizations, Peter Rocky Toves Jan 2015

Evaluating Success Factors In Implementing E-Maintenance In Maintenance, Repair, And Overhaul (Mro) Organizations, Peter Rocky Toves

Walden Dissertations and Doctoral Studies

Despite more than a decade-long process to transition aircraft maintenance practices from paper-to electronic-based systems, some organizations remain unable to complete this transition. Researchers have indicated that while organizations have invested resources in technology improvements, there remains a limited understanding of the factors that contribute to effectively managing technology-enabled change. The purpose of this case study was to identify and explore socio-technical (ST) factors that inhibit an effective transition from a paper-based system to an electronic-based system for aircraft maintenance. A conceptual model applying theories of change management, technology acceptance, systems thinking, and ST theory informed the research. Thirteen participants …


Human Factors In Textual Password-Based Authentication, S M Taiabul Haque Jan 2015

Human Factors In Textual Password-Based Authentication, S M Taiabul Haque

Computer Science and Engineering Dissertations - Archive

Despite being the most commonly used method of authentication on the Web, textual password-based authentication is by no means a panacea as long as usability is concerned. In this dissertation work, we address some usability issues of textual password-based authentication and propose solutions to them. In our first work, we examine the problem of multiple password management and identify the mental model of users for managing multiple password-protected accounts. We propose a hierarchy of password importance and use an experiment to examine the degree ofsimilarity between passwords for lower-level (e.g. news portal) and higher-level (e.g. banking) websites in this hierarchy. …


Simultaneous Optimization Of Performance, Energy, And Temperature While Allocating Tasks To Multi-Cores, Hafiz Fahad Sheikh Jan 2015

Simultaneous Optimization Of Performance, Energy, And Temperature While Allocating Tasks To Multi-Cores, Hafiz Fahad Sheikh

Computer Science and Engineering Dissertations - Archive

Multi-core processors have emerged as a solution to the problem of ever-increasing demands for computing power. However, higher power dissipation levels resulting into thermal problems and increasing cooling costs are major factors limiting their scalability into larger systems. Therefore, dynamic thermal management (DTM) and dynamic power management (DPM) of multi/many-core systems have emerged as important areas of research. The existing resource management approaches are either energy-aware or thermal-aware. In this dissertation, we focus on a new problem of simultaneous performance (P), energy (E), and temperature (T) optimized scheduling (PETOS) for allocating tasks to multi-core systems. To allocate a set of …


Pedagogical Possibilities For The 2048 Puzzle Game, Todd W. Neller Jan 2015

Pedagogical Possibilities For The 2048 Puzzle Game, Todd W. Neller

Computer Science Faculty Publications

In this paper, we describe an engaging puzzle game called 2048 and outline a variety of exercises that can leverage the game’s popularity to engage student interest, reinforce core CS concepts, and excite student curiosity towards undergraduate research. Exercises range in difficulty from CS1-level exercises suitable for exercising and assessing 1D and 2D array skills to empirical undergraduate research in Monte Carlo Tree Search methods and skilled heuristic evaluation design.


Computerized Evaluatution Of Microsurgery Skills Training, Payal Jotwani Jan 2015

Computerized Evaluatution Of Microsurgery Skills Training, Payal Jotwani

Electronic Theses and Dissertations

The style of imparting medical training has evolved, over the years. The traditional methods of teaching and practicing basic surgical skills under apprenticeship model, no longer occupy the first place in modern technically demanding advanced surgical disciplines like neurosurgery. Furthermore, the legal and ethical concerns for patient safety as well as cost-effectiveness have forced neurosurgeons to master the necessary microsurgical techniques to accomplish desired results. This has lead to increased emphasis on assessment of clinical and surgical techniques of the neurosurgeons. However, the subjective assessment of microsurgical techniques like micro-suturing under the apprenticeship model cannot be completely unbiased. A few …


Opportunistic Spectrum Utilization By Cognitive Radio Networks: Challenges And Solutions, Muhammad Faisal Amjad Jan 2015

Opportunistic Spectrum Utilization By Cognitive Radio Networks: Challenges And Solutions, Muhammad Faisal Amjad

Electronic Theses and Dissertations

Cognitive Radio Network (CRN) is an emerging paradigm that makes use of Dynamic Spectrum Access (DSA) to communicate opportunistically, in the un-licensed Industrial, Scientific and Medical bands or frequency bands otherwise licensed to incumbent users such as TV broadcast. Interest in the development of CRNs is because of severe under-utilization of spectrum bands by the incumbent Primary Users (PUs) that have the license to use them coupled with an ever-increasing demand for unlicensed spectrum for a variety of new mobile and wireless applications. The essence of Cognitive Radio (CR) operation is the cooperative and opportunistic utilization of licensed spectrum bands …