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2011

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Articles 571 - 600 of 1795

Full-Text Articles in Computer Sciences

Online Auc Maximization, Peilin Zhao, Steven C. H. Hoi, Rong Jin, Tianbo Yang Jul 2011

Online Auc Maximization, Peilin Zhao, Steven C. H. Hoi, Rong Jin, Tianbo Yang

Research Collection School Of Computing and Information Systems

Most studies of online learning measure the performance of a learner by classification accuracy, which is inappropriate for applications where the data are unevenly distributed among different classes. We address this limitation by developing online learning algorithm for maximizing Area Under the ROC curve (AUC), a metric that is widely used for measuring the classification performance for imbalanced data distributions. The key challenge of online AUC maximization is that it needs to optimize the pairwise loss between two instances from different classes. This is in contrast to the classical setup of online learning where the overall loss is a sum …


Using The Web Infrastructure For Real Time Recovery Of Missing Web Pages, Martin Klein Jul 2011

Using The Web Infrastructure For Real Time Recovery Of Missing Web Pages, Martin Klein

Computer Science Theses & Dissertations

Given the dynamic nature of the World Wide Web, missing web pages, or "404 Page not Found" responses, are part of our web browsing experience. It is our intuition that information on the web is rarely completely lost, it is just missing. In whole or in part, content often moves from one URI to another and hence it just needs to be (re-)discovered. We evaluate several methods for a \justin- time" approach to web page preservation. We investigate the suitability of lexical signatures and web page titles to rediscover missing content. It is understood that web pages change over time …


A Framework For Dynamic Traffic Monitoring Using Vehicular Ad-Hoc Networks, Mohammad Hadi Arbabi Jul 2011

A Framework For Dynamic Traffic Monitoring Using Vehicular Ad-Hoc Networks, Mohammad Hadi Arbabi

Computer Science Theses & Dissertations

Traffic management centers (TMCs) need high-quality data regarding the status of roadways for monitoring and delivering up-to-date traffic conditions to the traveling public. Currently this data is measured at static points on the roadway using technologies that have significant maintenance requirements. To obtain an accurate picture of traffic on any road section at any time requires a real-time probe of vehicles traveling in that section. We envision a near-term future where network communication devices are commonly included in new vehicles. These devices will allow vehicles to form vehicular networks allowing communication among themselves, other vehicles, and roadside units (RSUs) to …


Mining Weakly Labeled Web Facial Images For Search-Based Face Annotation, Dayang Wang, Steven C. H. Hoi, Ying He Jul 2011

Mining Weakly Labeled Web Facial Images For Search-Based Face Annotation, Dayang Wang, Steven C. H. Hoi, Ying He

Research Collection School Of Computing and Information Systems

In this paper, we investigate a search-based face annotation framework by mining weakly labeled facial images that are freely available on the internet. A key component of such a search-based annotation paradigm is to build a database of facial images with accurate labels. This is however challenging since facial images on the WWW are often noisy and incomplete. To improve the label quality of raw web facial images, we propose an effective Unsupervised Label Refinement (ULR) approach for refining the labels of web facial images by exploring machine learning techniques. We develop effective optimization algorithms to solve the large-scale learning …


Solution Pluralism And Metaheuristics, Steven O. Kimbrough, Ann Kuo, Hoong Chuin Lau, Frederic H. Murphy, David Harlan Wood Jul 2011

Solution Pluralism And Metaheuristics, Steven O. Kimbrough, Ann Kuo, Hoong Chuin Lau, Frederic H. Murphy, David Harlan Wood

Research Collection School Of Computing and Information Systems

Solution pluralism is an approach to problem solving and deliberation. It employs a plurality of distinct solutions for a decision problem for aiding decision making. The concept is well established in existing practice, although perhaps not recognized as such. This paper: (1) presents the concept as a generalization of established practice, (2) briefly describes successful uses of the concept in practice, and (3) presents several areas that appear would benefit from application of the concept. Throughout, the role of metaheuristics in finding the pluralities of solutions is emphasized.


Parallel Learning To Rank For Information Retrieval, Shuaiqiang Wang, Byron J. Gao, Ke Wang, Hady W. Lauw Jul 2011

Parallel Learning To Rank For Information Retrieval, Shuaiqiang Wang, Byron J. Gao, Ke Wang, Hady W. Lauw

Research Collection School Of Computing and Information Systems

Learning to rank represents a category of effective ranking methods for information retrieval. While the primary concern of existing research has been accuracy, learning efficiency is becoming an important issue due to the unprecedented availability of large-scale training data and the need for continuous update of ranking functions. In this paper, we investigate parallel learning to rank, targeting simultaneous improvement in accuracy and efficiency.


Scalable Multiagent Planning Using Probabilistic Inference, Akshat Kumar, Shlomo Zilberstein, Marc Toussaint Jul 2011

Scalable Multiagent Planning Using Probabilistic Inference, Akshat Kumar, Shlomo Zilberstein, Marc Toussaint

Research Collection School Of Computing and Information Systems

Multiagent planning has seen much progress with the development of formal models such as Dec-POMDPs. However, the complexity of these models -- NEXP-Complete even for two agents -- has limited scalability. We identify certain mild conditions that are sufficient to make multiagent planning amenable to a scalable approximation w.r.t. the number of agents. This is achieved by constructing a graphical model in which likelihood maximization is equivalent to plan optimization. Using the Expectation-Maximization framework for likelihood maximization, we show that the necessary inference can be decomposed into processes that often involve a small subset of agents, thereby facilitating scalability. We …


Message-Passing Algorithms For Quadratic Programming Formulations Of Map Estimation, Akshat Kumar, Shlomo Zilberstein Jul 2011

Message-Passing Algorithms For Quadratic Programming Formulations Of Map Estimation, Akshat Kumar, Shlomo Zilberstein

Research Collection School Of Computing and Information Systems

Computing maximum a posteriori (MAP) estimation in graphical models is an important inference problem with many applications. We present message-passing algorithms for quadratic programming (QP) formulations of MAP estimation for pairwise Markov random fields. In particular, we use the concave-convex procedure (CCCP) to obtain a locally optimal algorithm for the non-convex QP formulation. A similar technique is used to derive a globally convergent algorithm for the convex QP relaxation of MAP. We also show that a recently developed expectation-maximization (EM) algorithm for the QP formulation of MAP can be derived from the CCCP perspective. Experiments on synthetic and real-world problems …


Unsupervised Discovery Of Discourse Relations For Eliminating Intra-Sentence Polarity Ambiguities, Lanjun Zhou, Binyang Li, Wei Gao, Zhongyu Wei, Kam-Fai Wong Jul 2011

Unsupervised Discovery Of Discourse Relations For Eliminating Intra-Sentence Polarity Ambiguities, Lanjun Zhou, Binyang Li, Wei Gao, Zhongyu Wei, Kam-Fai Wong

Research Collection School Of Computing and Information Systems

Polarity classification of opinionated sentences with both positive and negative sentiments1 is a key challenge in sentiment analysis. This paper presents a novel unsupervised method for discovering intra-sentence level discourse relations for eliminating polarity ambiguities. Firstly, a discourse scheme with discourse constraints on polarity was defined empirically based on Rhetorical Structure Theory (RST). Then, a small set of cuephrase-based patterns were utilized to collect a large number of discourse instances which were later converted to semantic sequential representations (SSRs). Finally, an unsupervised method was adopted to generate, weigh and filter new SSRs without cue phrases for recognizing discourse relations. Experimental …


Unsupervised Information Extraction With Distributional Prior Knowledge, Cane Wing-Ki Leung, Jing Jiang, Kian Ming A. Chai, Hai Leong Chieu, Loo-Nin Teow Jul 2011

Unsupervised Information Extraction With Distributional Prior Knowledge, Cane Wing-Ki Leung, Jing Jiang, Kian Ming A. Chai, Hai Leong Chieu, Loo-Nin Teow

Research Collection School Of Computing and Information Systems

We address the task of automatic discovery of information extraction template from a given text collection. Our approach clusters candidate slot fillers to identify meaningful template slots. We propose a generative model that incorporates distributional prior knowledge to help distribute candidates in a document into appropriate slots. Empirical results suggest that the proposed prior can bring substantial improvements to our task as compared to a K-means baseline and a Gaussian mixture model baseline. Specifically, the proposed prior has shown to be effective when coupled with discriminative features of the candidates.


Linking Entities To A Knowledge Base With Query Expansion, Swapna Gottipati, Jing Jiang Jul 2011

Linking Entities To A Knowledge Base With Query Expansion, Swapna Gottipati, Jing Jiang

Research Collection School Of Computing and Information Systems

In this paper we present a novel approach to entity linking based on a statistical language model-based information retrieval with query expansion. We use both local contexts and global world knowledge to expand query language models. We place a strong emphasis on named entities in the local contexts and explore a positional language model to weigh them differently based on their distances to the query. Our experiments on the TAC-KBP 2010 data show that incorporating such contextual information indeed aids in disambiguating the named entities and consistently improves the entity linking performance. Compared with the official results from KBP 2010 …


Generating Aspect-Oriented Multi-Document Summarization With Event-Aspect Model, Peng Li, Yinglin Wang, Wei Gao, Jing Jiang Jul 2011

Generating Aspect-Oriented Multi-Document Summarization With Event-Aspect Model, Peng Li, Yinglin Wang, Wei Gao, Jing Jiang

Research Collection School Of Computing and Information Systems

In this paper, we propose a novel approach to automatic generation of aspect-oriented summaries from multiple documents. We first develop an event-aspect LDA model to cluster sentences into aspects. We then use extended LexRank algorithm to rank the sentences in each cluster. We use Integer Linear Programming for sentence selection. Key features of our method include automatic grouping of semantically related sentences and sentence ranking based on extension of random walk model. Also, we implement a new sentence compression algorithm which use dependency tree instead of parser tree. We compare our method with four baseline methods. Quantitative evaluation based on …


Automated Detection Of Likely Design Flaws In Layered Architectures, Aditya Budi, - Lucia, David Lo, Lingxiao Jiang, Shaowei Wang Jul 2011

Automated Detection Of Likely Design Flaws In Layered Architectures, Aditya Budi, - Lucia, David Lo, Lingxiao Jiang, Shaowei Wang

Research Collection School Of Computing and Information Systems

Layered architecture prescribes a good principle for separating concerns to make systems more maintainable. One example of such layered architectures is the separation of classes into three groups: Boundary, Control, and Entity, which are referred to as the three analysis class stereotypes in UML. Classes of different stereotypes are interacting with one another, when properly designed, the overall interaction would be maintainable, flexible, and robust. On the other hand, poor design would result in less maintainable system that is prone to errors. In many software projects, the stereotypes of classes are often missing, thus detection of design flaws becomes non-trivial. …


Masthead Jun 2011

Masthead

Journal of Digital Forensics, Security and Law

No abstract provided.


Back Matter Jun 2011

Back Matter

Journal of Digital Forensics, Security and Law

No abstract provided.


A Novel Methodology For Evaluating User Interfaces In Health Care, Luca Longo, Bridget Kane Jun 2011

A Novel Methodology For Evaluating User Interfaces In Health Care, Luca Longo, Bridget Kane

Conference papers

A pilot study is reported to identify an improved method of evaluating digital user interfaces in health care. Experience and developments from the aviation industry and the NASA-TLX mental workload assessment tools are applied in conjunction with Nielsen heuristics for evaluating an Electronic Health Record System in an Irish hospital. The NASA-TLX performs subjective workload assessments on operators working with various human-computer systems. Results suggest that depending on the cognitive workload and the working context of users, the usability will differ for the same digital interface. We conclude that incorporating the NASA-TLX with Nielsen's heuristics offers a more reliable method …


Front Matter Jun 2011

Front Matter

Journal of Digital Forensics, Security and Law

No abstract provided.


How Can Software Smes Become Medical Device, Fergal Mccaffery, Valentine Casey, Martin Mchugh Jun 2011

How Can Software Smes Become Medical Device, Fergal Mccaffery, Valentine Casey, Martin Mchugh

Conference papers

The amount of software content within medical devices has grown considerably over recent years and will continue to do so as the level of complexity of medical devices increase. This is driven by the fact that software is introduced to produce sophisticated medical devices that would not be possible using only hardware. This therefore presents opportunities for software development SMEs to become medical device software development organisations. However, some obstacles need to be addressed and overcome in order to make the transition from being a generic software development organisation to becoming a medical device software development organisation. This paper describes …


Experimental Performance Evaluation Of Atp (Ad-Hoc Transport Protocol) In A Wireless Mesh Network, Xingang Zhang Jun 2011

Experimental Performance Evaluation Of Atp (Ad-Hoc Transport Protocol) In A Wireless Mesh Network, Xingang Zhang

Theses and Dissertations

It is well known that TCP performs poorly in wireless mesh networks. There has been intensive research in this area, but most work uses simulation as the only evaluation method; however, it is not clear whether the performance gains seen with simulation will translate into benefits on real networks. To explore this issue, we have implemented ATP (Ad-hoc Transport Protocol), a transport protocol designed specifically for wireless ad hoc networks. We have chosen ATP because it uses a radically different design from TCP and because reported results claim significant improvement over TCP. We show how ATP must be modified in …


Rendering Realistic Cloud Effects For Computer Generated Films, Cory A. Reimschussel Jun 2011

Rendering Realistic Cloud Effects For Computer Generated Films, Cory A. Reimschussel

Theses and Dissertations

This work addresses the problem of rendering clouds. The task of rendering clouds is important to film and video game directors who want to use clouds to further the story or create a specific atmosphere for the audience. While there has been significant progress in this area, other solutions to this problem are inadequate because they focus on speed instead of accuracy, or focus only on a few specific properties of rendered clouds while ignoring others. Another common shortcoming with other methods is that they are not integrated into existing rendering pipelines. We propose a solution to this problem based …


Dsg-N²: A Group-Based Social Routing Algorithm, Roy Cabaniss, James M. Bridges, Andrew Wilson, Sanjay Madria Jun 2011

Dsg-N²: A Group-Based Social Routing Algorithm, Roy Cabaniss, James M. Bridges, Andrew Wilson, Sanjay Madria

Computer Science Faculty Research & Creative Works

Devices in a mobile ad-hoc environment can follow different movement patterns based on the application environment. Some environments, such as mass transit systems, follow regular and predictable patterns. Others, such as an aerial monitoring network, generally follow random paths. Optimal routing schemes tend to take advantage of information regarding movement patterns available in social interaction domains. in a social environment like wildlife tracking or monitoring socio-human interactions, the devices and/or users will follow regular contact habits, tending to encounter social groups in which they participate. in this paper, by dynamically identifying these groups, the patterns are used to speed routing …


Localization Of Objects Using Stochastic Tunneling, Mohammed Rana Basheer, Sarangapani Jagannathan Jun 2011

Localization Of Objects Using Stochastic Tunneling, Mohammed Rana Basheer, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a novel wireless localization scheme in the three-dimensional domain that employs stochastic optimization with tunneling transformation to recursively estimate the location of wireless tags in a network from pair wise signal strength measurements. Spatially co-located wireless tags, receiving signals from a common transmitter, exhibit correlation in their Received Signal Strength Indicator (RSSI) values. Hence in a network of wireless tags, with pair wise correlation coefficients available, posterior distribution of the unknown tag separation is used to relatively localize them using maximum a posteriori (MAP) Estimator. However, due to the non-convex/non-tractable nature of this posterior distribution, deterministic optimization …


A Study Analyzing Five Instructional Methods For Teaching Software To Junior High Students, Scott Ronald Bartholomew Jun 2011

A Study Analyzing Five Instructional Methods For Teaching Software To Junior High Students, Scott Ronald Bartholomew

Theses and Dissertations

If you ask 5 different teachers what the best way to teach a new technology to a student is you will get 5 different answers. (Bork, 2001; Cheong, 2008; Egal, 2009; Howell, 2001) What is the best way to teach a new computer software application to a student? In the technological world we live in today the effective transfer of technological knowledge is paramount. With varying opinions even among the leaders of national technology teacher associations (Haynie, 2005) there is a large level of ambiguity in relation to best practices in technology teaching. This study evaluates five commonly used methods …


Real-Time Visualizations Of Ocean Data Collected By The Norus Glider In Svalbad, Norway, Daniel Medina, Mark A. Moline, Christopher M. Clark, Zoë J. Wood Jun 2011

Real-Time Visualizations Of Ocean Data Collected By The Norus Glider In Svalbad, Norway, Daniel Medina, Mark A. Moline, Christopher M. Clark, Zoë J. Wood

Computer Science and Software Engineering

Modern robotics and sensors have expanded the ability to collect science data in underwater settings. Oftentimes, the collected data are deposited into files and databases where they sit in their separate and unique formats. Without easy to use visualization tools, it is difficult to understand and interpret the information within these data sets. NORUS, the North America-Norway educational program, has a scientific focus on how climate-induced changes impact the living resources and ecosystems in the Arctic. In order to obtain the necessary science data, the NORUS program utilizes the Slocum Glider, a form of underwater robot. We present a compelling, …


Multi-Robot Coalition Formation For Distributed Area Coverage, Ke Cheng Jun 2011

Multi-Robot Coalition Formation For Distributed Area Coverage, Ke Cheng

Student Work

The problem of distributed area coverage using multiple mobile robots is an important problem in distributed multi-robot sytems. Multi-robot coverage is encountered in many real world applications, including unmanned search & rescue, aerial reconnaissance, robotic demining, inspection of engineering structures, and automatic lawn mowing. To achieve optimal coverage, robots should move in an efficient manner and reduce repeated coverage of the same region that optimizes a certain performance metric such as the amount of time or energy expended by the robots. This dissertation especially focuses on using mini-robots with limited capabilities, such as low speed of the CPU and limited …


A Fuzzy Logic Stock Trading System Based On Technical Analysis, Sammy Zeigenbein Jun 2011

A Fuzzy Logic Stock Trading System Based On Technical Analysis, Sammy Zeigenbein

Regis University Student Publications (comprehensive collection)

Technical analysis of financial markets involves analyzing past price movements in order to identify favorable trading opportunities. The objective of this research was to demonstrate that a fuzzy logic stock trading system based on technical analysis can assist average traders in becoming successful by optimizing the use of technical indicators and trading rules that experts use to identify when to buy and sell stock. Research of relevant literature explored the current state of knowledge in methodologies for developing and validating trading systems using technical indicators and fuzzy logic trading systems, providing guidelines for the development and evaluation of the system. …


Combinational Circuit Obfuscation Through Power Signature Manipulation, Hyunchul Ko Jun 2011

Combinational Circuit Obfuscation Through Power Signature Manipulation, Hyunchul Ko

Theses and Dissertations

Today's military systems are composed of hardware and software systems, many of which are critical technologies, and must be protected to ensure our adversaries cannot gain any information from a various analysis attacks. Side Channel Analysis (SCA) attacks allow an attacker to gain the significant information from the measured signatures leaked by side-channels such as power consumption, and electro-magnetic emission. In this research the focus on detecting, characterizing, and manipulating the power signature by designing a power signature estimation and manipulation method. This research has determined that the proposed method capable of characterizing and altering the type of power signature …


Estimating Anthropometric Marker Locations From 3-D Ladar Point Clouds, Matthew J. Maier Jun 2011

Estimating Anthropometric Marker Locations From 3-D Ladar Point Clouds, Matthew J. Maier

Theses and Dissertations

An area of interest for improving the identification portion of the system is in extracting anthropometric markers from a Laser Detection and Ranging (LADAR) point cloud. Analyzing anthropometrics markers is a common means of studying how a human moves and has been shown to provide good results in determining certain demographic information about the subject. This research examines a marker extraction method utilizing principal component analysis (PCA), self-organizing maps (SOM), alpha hulls, and basic anthropometric knowledge. The performance of the extraction algorithm is tested by performing gender classification with the calculated markers.


Short Paper: The Netsani Framework For Analysis And Fine-Tuning Of Network Trace Sanitization, Phil Fazio, Keren Tan, Jihwang Yeo, David Kotz Jun 2011

Short Paper: The Netsani Framework For Analysis And Fine-Tuning Of Network Trace Sanitization, Phil Fazio, Keren Tan, Jihwang Yeo, David Kotz

Dartmouth Scholarship

Anonymization is critical prior to sharing wireless-network traces within the research community, to protect both personal and organizational sensitive information from disclosure. One difficulty in anonymization, or more generally, sanitization, is that users lack information about the quality of a sanitization result, such as how much privacy risk a sanitized trace may expose, and how much research utility the sanitized trace may retain. We propose a framework, NetSANI, that allows users to analyze and control the privacy/utility tradeoff in network sanitization. NetSANI can accommodate most of the currently available privacy and utility metrics for network trace sanitization. This framework provides …


Us Fda Releases Final Rule On Medical Device Data Systems:What Does This Mean For Device Manufacturers, Martin Mchugh, Fergal Mccaffery, Valentine Casey Jun 2011

Us Fda Releases Final Rule On Medical Device Data Systems:What Does This Mean For Device Manufacturers, Martin Mchugh, Fergal Mccaffery, Valentine Casey

Articles

On 16 April 2011, the US Food and Drug Administration’s (FDA’s) final rule on medical device data systems (MDDSs) came into force. This rule attempts to remove the uncertainty surrounding the safety classification of certain information technology systems used in healthcare. Devices that now meet the criteria of being an MDDS are classified as Class I (general controls). However, this final ruling explicitly precludes specific software applications that meet the definition of an MDDS, such as electronic health record applications and computerised physician order entry applications, as being beyond the scope of an MDDS. Similarly, ambiguity still remains surrounding mobile …