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2012

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Articles 781 - 810 of 1947

Full-Text Articles in Computer Sciences

Visualizing Media Bias Through Twitter, Jisun An, Meeyoung Cha, Gummadi, Krishna, Jon Crowcroft, Daniele Queria Jun 2012

Visualizing Media Bias Through Twitter, Jisun An, Meeyoung Cha, Gummadi, Krishna, Jon Crowcroft, Daniele Queria

Research Collection School Of Computing and Information Systems

Traditional media outlets are known to report political news in a biased way, potentially affecting the political beliefs of the audience and even altering their voting behaviors. Therefore, tracking bias in everyday news and building a platform where people can receive balanced news information is important. We propose a model that maps the news media sources along a dimensional dichotomous political spectrum using the co-subscriptions relationships inferred by Twitter links. By analyzing 7 million follow links, we show that the political dichotomy naturally arises on Twitter when we only consider direct media subscription. Furthermore, we demonstrate a real-time Twitter-based application …


Mining Quantified Temporal Rules: Formalism, Algorithms, And Evaluation, David Lo, Ganesan Ramalingam, Venkatesh Prasad Ranganath, Kapil Vaswani Jun 2012

Mining Quantified Temporal Rules: Formalism, Algorithms, And Evaluation, David Lo, Ganesan Ramalingam, Venkatesh Prasad Ranganath, Kapil Vaswani

Research Collection School Of Computing and Information Systems

Libraries usually impose constraints on how clients should use them. Often these constraints are not well-documented. In this paper, we address the problem of recovering such constraints automatically, a problem referred to as specification mining. Given some client programs that use a given library, we identify constraints on the library usage that are (almost) satisfied by the given set of clients.The class of rules we target for mining combines simple binary temporal operators with state predicates (composed of equality constraints) and quantification. This is a simple yet expressive subclass of temporal properties (LTL formulae) that allows us to capture many …


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 …


Flexrender: A Distributed Rendering Architecture For Ray Tracing Huge Scenes On Commodity Hardware., Robert Edward Somers Jun 2012

Flexrender: A Distributed Rendering Architecture For Ray Tracing Huge Scenes On Commodity Hardware., Robert Edward Somers

Master's Theses

As the quest for more realistic computer graphics marches steadily on, the demand for rich and detailed imagery is greater than ever. However, the current "sweet spot" in terms of price, power consumption, and performance is in commodity hardware. If we desire to render scenes with tens or hundreds of millions of polygons as cheaply as possible, we need a way of doing so that maximizes the use of the commodity hardware we already have at our disposal.

Techniques such as normal mapping and level of detail have attempted to address the problem by reducing the amount of geometry in …


Adaptive Security-Aware Scheduling For Packet Switched Networks Using Real-Time Multi-Agent Systems, Ma'en Saleh Saleh Jun 2012

Adaptive Security-Aware Scheduling For Packet Switched Networks Using Real-Time Multi-Agent Systems, Ma'en Saleh Saleh

Dissertations

Conventional real-time scheduling algorithms are in care of timing constraints; they don’t pay any attention to enhance or optimize the real-time packet’s security performance. In this work, we propose an adaptive security-aware scheduling with congestion control mechanism for packet switching networks using real-time agentbased systems. The proposed system combines the functionality of real-time scheduling with the security service enhancement, where the real-time scheduling unit uses the differentiated-earliest-deadline-first (Diff-EDF) scheduler, while the security service enhancement scheme adopts a congestion control mechanism based on a resource estimation methodology.

The security service enhancement unit was designed based on two models: singlelayer and weighted …


Digital Evidence Education In Schools Of Law, Aaron Alva, Barbara Endicott-Popovsky May 2012

Digital Evidence Education In Schools Of Law, Aaron Alva, Barbara Endicott-Popovsky

Annual ADFSL Conference on Digital Forensics, Security and Law

An examination of State of Connecticut v. Julie Amero provides insight into how a general lack of understanding of digital evidence can cause an innocent defendant to be wrongfully convicted. By contrast, the 101-page opinion in Lorraine v. Markel American Insurance Co. provides legal precedence and a detailed consideration for the admission of digital evidence. An analysis of both cases leads the authors to recommend additions to Law School curricula designed to raise the awareness of the legal community to ensure such travesties of justice, as in the Amero case, don’t occur in the future. Work underway at the University …


A Case Study Of The Challenges Of Cyber Forensics Analysis Of Digital Evidence In A Child Pornography Trial, Richard Boddington May 2012

A Case Study Of The Challenges Of Cyber Forensics Analysis Of Digital Evidence In A Child Pornography Trial, Richard Boddington

Annual ADFSL Conference on Digital Forensics, Security and Law

Perfunctory case analysis, lack of evidence validation, and an inability or unwillingness to present understandable analysis reports adversely affect the outcome course of legal trials reliant on digital evidence. These issues have serious consequences for defendants facing heavy penalties or imprisonment yet expect their defence counsel to have clear understanding of the evidence. Poorly reasoned, validated and presented digital evidence can result in conviction of the innocent as well as acquittal of the guilty. A possession of child pornography Case Study highlights the issues that appear to plague case analysis and presentation of digital evidence relied on in these odious …


After Five Years Of E-Discovery Missteps: Sanctions Or Safe Harbor?, Milton Luoma, Vicki Luoma May 2012

After Five Years Of E-Discovery Missteps: Sanctions Or Safe Harbor?, Milton Luoma, Vicki Luoma

Annual ADFSL Conference on Digital Forensics, Security and Law

In 2003 the Zubulake case became the catalyst of change in the world of e-discovery. In that case Judge Shira Scheindlin of the United States District Court for the Southern District of New York set guidelines for e-discovery that served as the basis for amending the Federal Rules of Civil Procedure (FRCP) in December 2006. The amendments incorporated a number of concepts that were described by Judge Scheindlin in the Zubulake case. ( Zubulake v. UBS Warburg LLC, 2003) Since the Zubulake case and the FRCP amendments, numerous cases have interpreted these rules changes, but one of the main points …


Multi-Parameter Sensitivity Analysis Of A Bayesian Network From A Digital Forensic Investigation, Richard E. Overill, Echo P. Zhang, Kam-Pui Chow May 2012

Multi-Parameter Sensitivity Analysis Of A Bayesian Network From A Digital Forensic Investigation, Richard E. Overill, Echo P. Zhang, Kam-Pui Chow

Annual ADFSL Conference on Digital Forensics, Security and Law

A multi-parameter sensitivity analysis of a Bayesian network (BN) used in the digital forensic investigation of the Yahoo! email case has been performed using the principle of ‘steepest gradient’ in the parameter space of the conditional probabilities. This procedure delivers a more reliable result for the dependence of the posterior probability of the BN on the values used to populate the conditional probability tables (CPTs) of the BN. As such, this work extends our previous studies using singleparameter sensitivity analyses of BNs, with the overall aim of more deeply understanding the indicative use of BNs within the digital forensic and …


Facilitating Forensics In The Mobile Millennium Through Proactive Enterprise Security, Andrew R. Scholnick May 2012

Facilitating Forensics In The Mobile Millennium Through Proactive Enterprise Security, Andrew R. Scholnick

Annual ADFSL Conference on Digital Forensics, Security and Law

This work explores the impact of the emerging mobile communication device paradigm on the security-conscious enterprise, with regard to providing insights for proactive Information Assurance and facilitation of eventual Forensic analysis. Attention is given to technology evolution in the areas of best practices, attack vectors, software and hardware performance, access and activity monitoring, and architectural models.

Keywords: Forensics, enterprise security, mobile communication, best practices, attack vectors.


Structural Analysis And Auditing Of Snomed Hierarchies Using Abstraction Networks, Yue Wang May 2012

Structural Analysis And Auditing Of Snomed Hierarchies Using Abstraction Networks, Yue Wang

Dissertations

SNOMED is one of the leading healthcare terminologies being used worldwide. Due to its sheer volume and continuing expansion, it is inevitable that errors will make their way into SNOMED. Thus, quality assurance is an important part of its maintenance cycle.

A structural approach is presented in this dissertation, aiming at developing automated techniques that can aid auditors in the discovery of terminology errors more effectively and efficiently. Large SNOMED hierarchies are partitioned, based primarily on their relationships patterns, into concept groups of more manageable sizes. Three related abstraction networks with respect to a SNOMED hierarchy, namely the area taxonomy …


Effects Of Information Importance And Distribution On Information Exchange In Team Decision Making, Babajide James Osatuyi May 2012

Effects Of Information Importance And Distribution On Information Exchange In Team Decision Making, Babajide James Osatuyi

Dissertations

Teams in organizations are strategically built with members from domains and experiences so that a wider range of information and options can be pooled. This strategic team structure is based on the assumption that when team members share the information they have, the team as a whole can access a larger pool of information than any one member acting alone, potentially enabling them to make better decisions. However, studies have shown that teams, unlike individuals, sometimes do not effectively share and use the unique information available to them, leading to poorer decisions. Research on information sharing in team decision making …


Registration And Categorization Of Camera Captured Documents, Venkata Gopal Edupuganti May 2012

Registration And Categorization Of Camera Captured Documents, Venkata Gopal Edupuganti

Dissertations

Camera captured document image analysis concerns with processing of documents captured with hand-held sensors, smart phones, or other capturing devices using advanced image processing, computer vision, pattern recognition, and machine learning techniques. As there is no constrained capturing in the real world, the captured documents suffer from illumination variation, viewpoint variation, highly variable scale/resolution, background clutter, occlusion, and non-rigid deformations e.g., folds and crumples. Document registration is a problem where the image of a template document whose layout is known is registered with a test document image. Literature in camera captured document mosaicing addressed the registration of captured documents with …


Example Based Texture Synthesis And Quantification Of Texture Quality, Chandralekha De May 2012

Example Based Texture Synthesis And Quantification Of Texture Quality, Chandralekha De

Dissertations

Textures have been used effectively to create realistic environments for virtual worlds by reproducing the surface appearances. One of the widely-used methods for creating textures is the example based texture synthesis method. In this method of generating a texture of arbitrary size, an input image from the real world is provided. This input image is used for the basis of generating large textures. Various methods based on the underlying pattern of the image have been used to create these textures; however, the problem of finding an algorithm which provides a good output is still an open research issue. Moreover, the …


Asymptotic Statistics Of Nodal Domains Of Quantum Chaotic Billiards In The Semiclassical Limit, Kyle T. Konrad May 2012

Asymptotic Statistics Of Nodal Domains Of Quantum Chaotic Billiards In The Semiclassical Limit, Kyle T. Konrad

Dartmouth College Undergraduate Theses

Quantum chaos concerns eigenfunctions of the Laplace operator in a domain where a billiard ball would bounce chaotically. Such chaotic eigenfunctions have been conjectured to share statistical properties of their nodal domains with a simple percolation model, from which many interesting quantities can be computed analytically. We numerically test conjectures on the number and size of nodal domains of quantum chaotic eigenfunctions at very high energies, approaching the semiclassical limit. We use a highly efficient scaling method to quickly compute eigenfunctions at low resolution and interpolate to higher resolution. We computed 10^5 eigenfunctions and counted 10^9 nodal domains. Our results …


Simplified Models Of Vector Control Impact Upon Malaria Transmission By Zoophagic Mosquitoes, Samson S. Kiware, Nakul Chitnis, Sarah J. Moore, Gregor J. Devine, Silas Majambere, Stephen Merrill, Gerry F. Killeen May 2012

Simplified Models Of Vector Control Impact Upon Malaria Transmission By Zoophagic Mosquitoes, Samson S. Kiware, Nakul Chitnis, Sarah J. Moore, Gregor J. Devine, Silas Majambere, Stephen Merrill, Gerry F. Killeen

Mathematics, Statistics and Computer Science Faculty Research and Publications

Background

High coverage of personal protection measures that kill mosquitoes dramatically reduce malaria transmission where vector populations depend upon human blood. However, most primary malaria vectors outside of sub-Saharan Africa can be classified as “very zoophagic,” meaning they feed occasionally (

Methods and Findings

We extended a published malaria transmission model to examine the relationship between transmission, control, and the baseline proportion of bloodmeals obtained from humans (human blood index). The lower limit of the human blood index enables derivation of simplified models for zoophagic vectors that (1) Rely on only three field-measurable parameters. (2) Predict immediate and delayed (with …


Reducing The Risk Of Software Cost Estimation, Shixian Yang May 2012

Reducing The Risk Of Software Cost Estimation, Shixian Yang

Theses

Inaccurate cost estimation is a well-known problem in software development. The common cost estimation models are point estimates that are unable to quantify uncertainties. Furthermore, it is difficult to calibrate the uncertainties in cost estimation due to the lack of information. The purpose of this thesis is to prove that probability techniques could be synthesized into COCOMO (Constructive Cost Model) to quantify uncertainties. Another aim is to find out how to get more insight on reducing the risk of cost estimation. In this thesis, some historical data is presented to show the variance in factors of COCOMO. Monte Carlo simulation …


Phenotype Prediction And Feature Selection In Genome-Wide Association Studies, Andrew Roberts May 2012

Phenotype Prediction And Feature Selection In Genome-Wide Association Studies, Andrew Roberts

Theses

Genome wide association studies (GWAS) search for correlations between single nucleotide polymorphisms (SNPs) in a subject genome and an observed phenotype. GWAS can be used to generate models for predicting phenotype based on genotype, as well as aiding in identification of specific genes affecting the biological mechanism underlying the phenotype.

In this investigation, phenotype prediction models are constructed from GWAS training data and are evaluated for performance on test data. Three methods are used to rank SNPs by their correlation with the phenotype: the univariate Wald test, a multivariate, support vector machine (SVM) based technique, and a hybrid method where …


Heterogeneity-Aware And Energy-Aware Scheduling And Routing In Wireless Sensor Networks, Mahesh Kumar Vasanthu Somashekar May 2012

Heterogeneity-Aware And Energy-Aware Scheduling And Routing In Wireless Sensor Networks, Mahesh Kumar Vasanthu Somashekar

Theses

A Wireless Sensor Network (WSN) is a group of specialized transducers, called sensor nodes, with a communication infrastructure intended to monitor and record conditions at diverse locations. Since WSN applications are usually deployed in an open environment, the network is exposed to rough weather conditions, such as rain and snow. Another problem that WSN applications need to deal with is the energy constraints of sensor nodes. Both problems adversely affect the lifetime of WSN applications. A lot of research has been conducted to prolong the lifetime of WSN applications considering energy constraints of sensor nodes, but not much research has …


A Comparative Analysis Of Machine Learning Algorithms For Genome Wide Association Studies, Neha Singh May 2012

A Comparative Analysis Of Machine Learning Algorithms For Genome Wide Association Studies, Neha Singh

Theses

Variations present in human genome play a vital role in the emergence of genetic disorders and abnormal traits. Single Nucleotide Polymorphism (SNP) is considered as the most common source of genetic variations. Genome Wide Association Studies (GWAS) probe these variations present in human population and find their association with complex genetic disorders. Now these days, recent advances in technology and drastic reduction in costs of Genome Wide Association Studies provide the opportunity to have a plethora of genomic data that delivers huge information of these variations to analyze. In fact, there is significant difference in pace of data generation and …


Data Mining Of Tetraloop-Tetraloop Receptors In Rna Xml Files, Sinan Ramazanoglu May 2012

Data Mining Of Tetraloop-Tetraloop Receptors In Rna Xml Files, Sinan Ramazanoglu

Theses

RNA (Ribonucleic acid) Motifs are tertiary structures that play an important role in the folding mechanism of the RNA molecule. The overall function of a RNA Motif depends on its specific bp (base pairs) sequence that constitutes the secondary structure. Data mining is a novel method in both discovering potential tertiary structures within DNA (Deoxyribonucleic acid), RNA, and protein molecules and storing the information in databases. The RNA Motif of interest is the tetraloop-tetraloop receptor, which is composed of a highly conserved 11 nt (nucleotide) sequence and a tetraloop with the generic form of GNRA (where N = any base …


Cloud Forensics Investigation: Tracing Infringing Sharing Of Copyrighted Content In Cloud, Yi-Jun He, Echo P. Zhang, Lucas C.K. Hui, Siu Ming Yiu, K.P. Chow May 2012

Cloud Forensics Investigation: Tracing Infringing Sharing Of Copyrighted Content In Cloud, Yi-Jun He, Echo P. Zhang, Lucas C.K. Hui, Siu Ming Yiu, K.P. Chow

Annual ADFSL Conference on Digital Forensics, Security and Law

Cloud Computing is becoming a significant technology trend nowadays, but its abrupt rise also creates a brand new front for cybercrime investigation with various challenges. One of the challenges is to track down infringing sharing of copyrighted content in cloud. To solve this problem, we study a typical type of content sharing technologies in cloud computing, analyze the challenges that the new technologies bring to forensics, formalize a procedure to get digital evidences and obtain analytical results based on the evidences to track down illegal uploader. Furthermore, we propose a reasoning model based on the probability distribution in a Bayesian …


Ipad2 Logical Acquisition: Automated Or Manual Examination?, Somaya Ali, Sumaya Alhosani, Farah Alzarooni, Ibrahim Baggili May 2012

Ipad2 Logical Acquisition: Automated Or Manual Examination?, Somaya Ali, Sumaya Alhosani, Farah Alzarooni, Ibrahim Baggili

Annual ADFSL Conference on Digital Forensics, Security and Law

Due to their usage increase worldwide, iPads are on the path of becoming key sources of digital evidence in criminal investigations. This research investigated the logical backup acquisition and examination of the iPad2 device using the Apple iTunes backup utility while manually examining the backup data (manual examination) and automatically parsing the backup data (Lantern software - automated examination). The results indicate that a manual examination of the logical backup structure from iTunes reveals more digital evidence, especially if installed application data is required for an investigation. However, the researchers note that if a quick triage is needed of an …


A Fuzzy Hashing Approach Based On Random Sequences And Hamming Distance, Frank Breitinger, Harald Baier May 2012

A Fuzzy Hashing Approach Based On Random Sequences And Hamming Distance, Frank Breitinger, Harald Baier

Annual ADFSL Conference on Digital Forensics, Security and Law

Hash functions are well-known methods in computer science to map arbitrary large input to bit strings of a fixed length that serve as unique input identifier/fingerprints. A key property of cryptographic hash functions is that even if only one bit of the input is changed the output behaves pseudo randomly and therefore similar files cannot be identified. However, in the area of computer forensics it is also necessary to find similar files (e.g. different versions of a file), wherefore we need a similarity preserving hash function also called fuzzy hash function. In this paper we present a new approach for …


The Xbox 360 And Steganography: How Criminals And Terrorists Could Be "Going Dark", Ashley Podhradsky, Rob D’Ovidio, Cindy Casey May 2012

The Xbox 360 And Steganography: How Criminals And Terrorists Could Be "Going Dark", Ashley Podhradsky, Rob D’Ovidio, Cindy Casey

Annual ADFSL Conference on Digital Forensics, Security and Law

Video game consoles have evolved from single-player embedded systems with rudimentary processing and graphics capabilities to multipurpose devices that provide users with parallel functionality to contemporary desktop and laptop computers. Besides offering video games with rich graphics and multiuser network play, today's gaming consoles give users the ability to communicate via email, video and text chat; transfer pictures, videos, and file;, and surf the World-Wide-Web. These communication capabilities have, unfortunately, been exploited by people to plan and commit a variety of criminal activities. In an attempt to cover the digital tracks of these unlawful undertakings, anti-forensic techniques, such as steganography, …


Double-Compressed Jpeg Detection In A Steganalysis System, Jennifer L. Davidson, Pooja Parajape May 2012

Double-Compressed Jpeg Detection In A Steganalysis System, Jennifer L. Davidson, Pooja Parajape

Annual ADFSL Conference on Digital Forensics, Security and Law

The detection of hidden messages in JPEG images is a growing concern. Current detection of JPEG stego images must include detection of double compression: a JPEG image is double compressed if it has been compressed with one quality factor, uncompressed, and then re-compressed with a different quality factor. When detection of double compression is not included, erroneous detection rates are very high. The main contribution of this paper is to present an efficient double-compression detection algorithm that has relatively lower dimensionality of features and relatively lower computational time for the detection part, than current comparative classifiers. We use a model-based …


Toward Alignment Between Communities Of Practice And Knowledge-Based Decision Support, Jason Nichols, David Biros, Mark Weiser May 2012

Toward Alignment Between Communities Of Practice And Knowledge-Based Decision Support, Jason Nichols, David Biros, Mark Weiser

Annual ADFSL Conference on Digital Forensics, Security and Law

The National Repository of Digital Forensics Information (NRDFI) is a knowledge repository for law enforcement digital forensics investigators (LEDFI). Over six years, the NRDFI has undertaken significant design revisions in order to more closely align the architecture of the system with theory addressing motivation to share knowledge and communication within ego-centric groups and communities of practice. These revisions have been met with minimal change in usage patterns by LEDFI community members, calling into question the applicability of relevant theory when the domain for knowledge sharing activities expands beyond the confines of an individual organization to a community of practice. When …


A Proposal For Incorporating Programming Blunder As Important Evidence In Abstraction-Filtration-Comparison Test, P. Vinod Bhattathiripad May 2012

A Proposal For Incorporating Programming Blunder As Important Evidence In Abstraction-Filtration-Comparison Test, P. Vinod Bhattathiripad

Annual ADFSL Conference on Digital Forensics, Security and Law

This paper investigates an unexplored concept in Cyber Forensics, namely, a Programming Blunder. Programming Blunder is identified as a variable or a code segment or a field in a database table, which is hardly used or executed in the context of the application or the user’s functionality. Blunder genes can be found in many parts of any program. It is the contention of this paper that this phenomenon of blunders needs to be studied systematically from its very genetic origins to their surface realizations in contrast to bugs and flaws, especially in view of their importance in software copyright infringement …


Update On The State Of The Science Of Digital Evidence Examination, Fred Cohen May 2012

Update On The State Of The Science Of Digital Evidence Examination, Fred Cohen

Annual ADFSL Conference on Digital Forensics, Security and Law

This paper updates previous work on the level of consensus in foundational elements of digital evidence examination. Significant consensus is found present only after definitions are made explicit, suggesting that, while there is a scientific agreement around some of the basic notions identified, the use of a common language is lacking.

Keywords: Digital forensics examination, terminology, scientific methodology, testability, validation, classification, scientific consensus


A Data Flow Tracker And Reference Monitor For Webkit And Javascriptcore, Andrew Bloomgarden May 2012

A Data Flow Tracker And Reference Monitor For Webkit And Javascriptcore, Andrew Bloomgarden

Dartmouth College Undergraduate Theses

Browser security revolves around the same-origin policy, but it does not defend against all attacks as evidenced by the prevalence of cross-site scripting attacks. Rather than solve that attack in particular, I have opted for a more general solution. I have modified WebKit to allow data flow tracking via labels and to allow security-sensitive operations to be allowed or denied from JavaScript.