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2012

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Articles 31 - 53 of 53

Full-Text Articles in Programming Languages and Compilers

Xgrid And R: Parallel Distributed Processing Using Heterogeneous Groups Of Apple Computers, Sarah C. Anoke, Yuting Zhao, Rafael Jaeger, Nicholas J. Horton Jun 2012

Xgrid And R: Parallel Distributed Processing Using Heterogeneous Groups Of Apple Computers, Sarah C. Anoke, Yuting Zhao, Rafael Jaeger, Nicholas J. Horton

The R Journal

The Apple Xgrid system provides access to groups (or grids) of computers that can be used to facilitate parallel processing. We describe the xgrid package which facilitates access to this system to undertake independent simulations or other long-running jobs that can be divided into replicate runs within R. Detailed examples are provided to demonstrate the interface, along with results from a simulation study of the performance gains using a variety of grids. Use of the grid for “embarassingly parallel” independent jobs has the potential for major speedups in time to completion. Appendices provide guidance on setting up the workflow, utilizing …


Openair: Data Analysis Tools For The Air Quality Community, Karl Ropkins, David C. Carslaw Jun 2012

Openair: Data Analysis Tools For The Air Quality Community, Karl Ropkins, David C. Carslaw

The R Journal

The openair package contains data analysis tools for the air quality community. This paper provides an overview of data importers, main functions, and selected utilities and workhorse functions within the package and the function output class, as of package version 0.4-14. It is intended as an explanation of the rationale for the package and a technical description for those wishing to work more inter actively with the main functions or develop additional functions to support ‘higher level’ use of openair and R.


Maxent: An R Package For Low-Memory Multinomial Logistic Regression With Support For Semi-Automated Text Classification, Timothy P. Jurka Jun 2012

Maxent: An R Package For Low-Memory Multinomial Logistic Regression With Support For Semi-Automated Text Classification, Timothy P. Jurka

The R Journal

maxent is a package with tools for data classification using multinomial logistic regression, also known as maximum entropy. The focus of this maximum entropy classifier is to minimize memory consumption on very large datasets, particularly sparse document-term matrices represented by the tm text mining pack age.


Marss: Multivariate Autoregressive State-Space Models For Analyzing Time-Series Data, Elizabeth E. Holmes, Eric J. Ward, Kellie Wills Jun 2012

Marss: Multivariate Autoregressive State-Space Models For Analyzing Time-Series Data, Elizabeth E. Holmes, Eric J. Ward, Kellie Wills

The R Journal

MARSS is a package for fitting multivariate autoregressive state-space models to time-series data. The MARSS package implements state-space models in a maximum likelihood framework. The core functionality of MARSSis based on likelihood maximization using the Kalman filter/smoother, combined with an EM algorithm. To make comparisons with other packages available, parameter estimation is also permitted via direct search routines avail able in ’optim’. The MARSS package allows data to contain missing values and allows a wide variety of model structures and constraints to be specified (such as fixed or shared parameters). In addition to model-fitting, the package provides bootstrap routines for …


Vdgraph: A Package For Creating Variance Dispersion Graphs, John Lawson Jun 2012

Vdgraph: A Package For Creating Variance Dispersion Graphs, John Lawson

The R Journal

This article introduces the package Vdgraph that is used form a king variance dispersion graphs of response surface designs.The package includes functions that make the variance dispersion graph of one design or compare variance dispersion graphs of two designs, which are stored in data frames or matrices.The package also contains several minimum run response surface designs (stored as matrices) that are not available in other R packages.


Analysing Seasonal Data, Adrian G. Barnett, Peter Baker, Annette J. Dobson Jun 2012

Analysing Seasonal Data, Adrian G. Barnett, Peter Baker, Annette J. Dobson

The R Journal

Many common diseases, such as the flu and cardiovascular disease, increase markedly in winter and dip in summer. These seasonal patterns have been part of life for millennia and were first noted in ancient Greece by both Hippocrates and Herodotus. Recent interest has focused on climate change, and the concern that seasons will become more extreme with harsher winter and summer weather. We describe a set of R functions designed to model seasonal pat terns in disease. We illustrate some simple descriptive and graphical methods, a more complex method that is able to model non-stationary patterns, and the case-crossover to …


Foreign Library Interface, Daniel Adler Jun 2012

Foreign Library Interface, Daniel Adler

The R Journal

We present an improved Foreign Function Interface (FFI) for R to call arbitary native functions without the need for C wrapper code. Further we discuss a dynamic linkage framework for binding standard C libraries to R across platforms using a universal type information format. The package rdyncall comprises the framework and an initial repository of cross platform bindings for standard libraries such as (legacy and modern) OpenGL, the family of SDL libraries and Expat. The package enables system level programming using the R language; sample applications are given in the article. We out line the underlying automation tool-chain that extracts …


Sumo: An Authenticating Web Application With An Embedded R Session, Timothy T. Bergsma, Michael S. Smith Jun 2012

Sumo: An Authenticating Web Application With An Embedded R Session, Timothy T. Bergsma, Michael S. Smith

The R Journal

Sumo is a web application intended as a template for developers. It is distributed as a Java ‘war’ file that deploys automatically when placed in a Servlet container’s ‘webapps’ directory. If a user supplies proper credentials, Sumocreates a session-specific Secure Shell connection to the host and a user-specific R session over that connection. Developers may write dynamic server pages that make use of the persistent R session and user-specific file space. The supplied example plots a data set conditional on preferences indicated by the user; it also displays some static text. A companion server page al lows the user to …


Aligning Images In The Wild, Wen-Yan Lin, Linlin Liu, Yasuyuki Matsushita, Kok-Lim Low, Siying Liu Jun 2012

Aligning Images In The Wild, Wen-Yan Lin, Linlin Liu, Yasuyuki Matsushita, Kok-Lim Low, Siying Liu

Research Collection School Of Computing and Information Systems

Aligning image pairs with significant appearance change is a long standing computer vision challenge. Much of this problem stems from the local patch descriptors’ instability to appearance variation. In this paper we suggest this instability is due less to descriptor corruption and more the difficulty in utilizing local information to canonically define the orientation (scale and rotation) at which a patch’s descriptor should be computed. We address this issue by jointly estimating correspondence and relative patch orientation, within a hierarchical algorithm that utilizes a smoothly varying parameterization of geometric transformations. By collectively estimating the correspondence and orientation of all the …


Complexity Of The Soundness Problem Of Bounded Workflow Nets, Guan Jun Liu, Jun Sun, Yang Liu, Jin Song Dong Jun 2012

Complexity Of The Soundness Problem Of Bounded Workflow Nets, Guan Jun Liu, Jun Sun, Yang Liu, Jin Song Dong

Research Collection School Of Computing and Information Systems

Classical workflow nets (WF-nets) are an important class of Petri nets that are widely used to model and analyze workflow systems. Soundness is a crucial property that guarantees these systems are deadlock-free and bounded. Aalst et al. proved that the soundness problem is decidable, and proposed (but not proved) that the soundness problem is EXPSPACE-hard. In this paper, we show that the satisfiability problem of Boolean expression is polynomial time reducible to the liveness problem of bounded WF-nets, and soundness and liveness are equivalent for bounded WF-nets. As a result, the soundness problem of bounded WF-nets is co-NP-hard.Workflow nets with …


Cuda Web Api Remote Execution Of Cuda Kernels Using Web Services, Massimo J. Becker Jun 2012

Cuda Web Api Remote Execution Of Cuda Kernels Using Web Services, Massimo J. Becker

Master's Theses

Massively parallel programming is an increasingly growing field with the recent introduction of general purpose GPU computing. Modern graphics processors from NVIDIA and AMD have massively parallel architectures that can be used for such applications as 3D rendering, financial analysis, physics simulations, and biomedical analysis. These massively parallel systems are exposed to programmers through in- terfaces such as NVIDIAs CUDA, OpenCL, and Microsofts C++ AMP. These frame- works expose functionality using primarily either C or C++. In order to use these massively parallel frameworks, programs being implemented must be run on machines equipped with massively parallel hardware. These requirements limit …


Pointcut Rejuvenation: Recovering Pointcut Expressions In Evolving Aspect-Oriented Software, Raffi Khatchadourian, Phil Greenwood, Awais Rashid, Harry Xu May 2012

Pointcut Rejuvenation: Recovering Pointcut Expressions In Evolving Aspect-Oriented Software, Raffi Khatchadourian, Phil Greenwood, Awais Rashid, Harry Xu

Publications and Research

Pointcut fragility is a well-documented problem in Aspect-Oriented Programming; changes to the base code can lead to join points incorrectly falling in or out of the scope of pointcuts. In this paper, we present an automated approach that limits fragility problems by providing mechanical assistance in pointcut maintenance. The approach is based on harnessing arbitrarily deep structural commonalities between program elements corresponding to join points selected by a pointcut. The extracted patterns are then applied to later versions to offer suggestions of new join points that may require inclusion. To illustrate that the motivation behind our proposal is well founded, …


Node Filtering And Face Routing For Sensor Network, Umang Amatya Apr 2012

Node Filtering And Face Routing For Sensor Network, Umang Amatya

College of Engineering: Graduate Celebration Programs

Main Contributions

•Efficient Algorithms for identifying Redundant Sensor Nodes

•New Technique for Filtering Redundant Nodes in Sensor Network

•Reliable Algorithm for Message Routing - Forwarding

•User Friendly Prototype Implementation in Java

•Results of Experimental Investigation


Extending Java For Android Programming, Yoonsik Cheon Apr 2012

Extending Java For Android Programming, Yoonsik Cheon

Departmental Technical Reports (CS)

Android is one of the most popular platforms for developing mobile applications. However, its framework relies on programming conventions and styles to implement framework-specific concepts like activities and intents, causing problems such as reliability, readability, understandability, and maintainability. We propose to extend Java to support Android framework concepts explicitly as built-in language features. Our extension called Android Java will allow Android programmers to express these concepts in a more reliable, natural, and succinct way.


Health Nexus: A Serious Game Prototype For Prevention And Treatment Of Obesity And Diabetes, Joseph C. Miller Apr 2012

Health Nexus: A Serious Game Prototype For Prevention And Treatment Of Obesity And Diabetes, Joseph C. Miller

Computational Modeling & Simulation Engineering Theses & Dissertations

Electronic games are a prevalent phenomenon of American culture and entertainment. Serious games are video games that take advantage of games' intrinsic entertaining and challenging characteristics for serious purposes, such as education, training, advertisement, and political campaigns. A significant number of serious games have been developed for a variety of diverse purposes. The last few years have witnessed the inception and growth of motion sensing technologies for games, including Nintendo Wii, Sony PlayStation Move, and Microsoft Kinect. These motion sensing technologies usually require game players' physical body movement in order to perform and achieve in the games, such as playing …


Programming In A Socially Networked World: The Evolution Of The Social Programmer, Christoph Treude, Fernando Figueira Filho, Brendan Cleary, Margaret-Anne Storey Feb 2012

Programming In A Socially Networked World: The Evolution Of The Social Programmer, Christoph Treude, Fernando Figueira Filho, Brendan Cleary, Margaret-Anne Storey

Research Collection School Of Computing and Information Systems

Social media has changed how software developers collaborate, how they coordinate their work, and where they find information. Social media sites, such as the Question and Answer (Q&A) portal Stack Overflow, fill archives with millions of entries that contribute to what we know about software development, covering a wide range of topics. For today’s software developers, reusable code snippets, introductory usage examples, and pertinent libraries are often just a web search away. In this position paper, we discuss the opportunities and challenges for software developers that rely on web content curated by the crowd, and we envision the future of …


Formal Modeling And Validation Of Stateflow Diagrams, Chunqing Chen, Jun Sun, Yang Liu, Jin Song Dong, Manchun Zheng Jan 2012

Formal Modeling And Validation Of Stateflow Diagrams, Chunqing Chen, Jun Sun, Yang Liu, Jin Song Dong, Manchun Zheng

Research Collection School Of Computing and Information Systems

Stateflow is an industrial tool for modeling and simulating control systems in model-based development. In this paper, we present our latest work on automatic verification of Stateflow using model-checking techniques. We propose an approach to systematically translate Stateflow diagrams to a formal modeling language called CSP# by precisely following Stateflow’s execution semantics, which is described by examples. A translator is developed inside the Process Analysis Toolkit (PAT) model checker to automate this process with the support of various Stateflow advanced modeling features. Formal analysis can be conducted on the transformed CSP# with PAT’s simulation and model-checking power. Using our approach, …


How Is M&S Interoperability Different From Other Interoperability Domains?, Andreas Tolk, Saikou Y. Diallo, Jose J. Padilla, Charles D. Turnitsa Jan 2012

How Is M&S Interoperability Different From Other Interoperability Domains?, Andreas Tolk, Saikou Y. Diallo, Jose J. Padilla, Charles D. Turnitsa

Computational Modeling & Simulation Engineering Faculty Publications

During every standard workshop or event, the examples of working interoperability solutions are used to motivate for 'plug and play' standards for M&S as well, like standardized batteries for electronics, or the use of XML to exchange data between heterogeneous systems. While these are successful applications of standards, they are off the mark regarding M&S interoperability. The challenge of M&S is that the product that needs to be made interoperable is not the service or the system alone, but the model behind it as well. The paper shows that the alignment of conceptualizations is the real problem that is not …


Patterns As Objects In Grace, Andrew P. Black, Michael Homer, James Noble, David J. Pearce, Kim B. Bruce Jan 2012

Patterns As Objects In Grace, Andrew P. Black, Michael Homer, James Noble, David J. Pearce, Kim B. Bruce

Computer Science Faculty Publications and Presentations

Object orientation and pattern matching are often seen as conflicting approaches to program design. Object oriented programs place type-dependent behaviour inside objects and invoke it via dynamic dispatch, while pattern matching programs place type-dependent behaviour outside data structures and invoke it via multiway conditionals (case statements). Grace is a new, dynamic, object-oriented language designed to support teaching: to this end, Grace needs to support both styles. In this paper we explain how this conflict can be resolved gracefully: by modelling patterns and cases as partial functions, reifying those functions as first-class objects, and then building up complex patterns from simpler …


Parallel Sorting On A Spatial Computer, Max Orhai, Andrew P. Black Jan 2012

Parallel Sorting On A Spatial Computer, Max Orhai, Andrew P. Black

Computer Science Faculty Publications and Presentations

We describe a parallel sort for a spatial computer that requires minimal communication. We show simulations of the sort in 1 and 2 dimensions.

Presentation slides are located below in the Additional Files


The Basic Scheme For The Evaluation Of Functional Logic Programs, Arthur Peters Jan 2012

The Basic Scheme For The Evaluation Of Functional Logic Programs, Arthur Peters

Dissertations and Theses

Functional logic languages provide a powerful programming paradigm combining the features of functional languages and logic languages. However, current implementations of functional logic languages are complex, slow, or both. This thesis presents a scheme, called the Basic Scheme, for compiling and executing functional logic languages based on non-deterministic graph rewriting. This thesis also describes the implementation and optimization of a prototype of the Basic Scheme. The prototype is simple and performs well compared to other current implementations.


Fusion Of Visual And Thermal Images Using Genetic Algorithms, Sertan Erkanli, Jiang Li, Ender Oguslu, Shangce Gao (Ed.) Jan 2012

Fusion Of Visual And Thermal Images Using Genetic Algorithms, Sertan Erkanli, Jiang Li, Ender Oguslu, Shangce Gao (Ed.)

Electrical & Computer Engineering Faculty Publications

No abstract provided.


A Hybridized Lagrangian Relaxation And Simulated Annealing Method For The Course Timetabling Problem, Aldy Gunawan, Kim Leng Poh Jan 2012

A Hybridized Lagrangian Relaxation And Simulated Annealing Method For The Course Timetabling Problem, Aldy Gunawan, Kim Leng Poh

Research Collection School Of Computing and Information Systems

This paper describes a timetabling problem at universities, where a master course timetable is given extrinsically and conflicts due to students' course enrollment do not need to be considered. A solver for the problem, which integrates both teacher assignment and course scheduling, is described. An initial solution is obtained by a mathematical programming approach based on Lagrangian relaxation. This solution is further improved by a simulated annealing algorithm. The proposed method has been tested on instances from a university in Indonesia, as well as on several randomly generated datasets, and the corresponding computational results are reported.