Computer Sciences Commons^™

Link Activity Scheduling For Minimum End-To-End Latency In Multihop Wireless Sensor Networks, Maggie X. Cheng, Xuan Gong, Yibo Xu, Lin Cai

Computer Science Faculty Research & Creative Works

End-to-end delay is an important QoS metric in sensor networks as well as any application that involves transferring of small-sized files. in this paper, we address how to minimize the end-to-end delay in a multihop wireless network. End-to-end delay is defined as the total time it takes for a single packet to reach the destination. It is a result of many factors including the length of the routing path and the interference level along the path. in this paper we present a transmission scheduling scheme that minimizes the end-to-end delay along a given route. the link scheduling scheme is based …

Information Flow Security In Cyber-Physical Systems, Thoshitha Gamage, Ravi Akella, Thomas Roth, Bruce Mcmillin

Computer Science Faculty Research & Creative Works

Preserving the confidentiality of sensitive internal actions is a unique challenge in Cyber-Physical Systems (CPSs) due to the inherent external observability of such systems and the tight coupling between their cyber and physical domains. the far-reaching objective of this work is to develop a science of self-obfuscating systems based on the composition of simple building blocks. a model of Nondeducibility composes the building blocks under information flow security properties. to this end, this paper proposes fundamental theories on external observability for basic regular networks and the concept of "event compensation". Copyright © 2011 ACM.

Edge-Guarding Orthogonal Polyhedra, Nadia M. Benbernou, Erik D. Demaine, Martin L. Demaine, Anastasia Kurdia, Joseph O'Rourke, Godfried Toussaint, Jorge Urrutia, Giovanni Viglietta

Computer Science: Faculty Publications

We address the question: How many edge guards are needed to guard an orthogonal polyhedron of e edges, r of which are reflex? It was previously established [3] that e/12 are sometimes necessary and e/6 always suf- fice. In contrast to the closed edge guards used for these bounds, we introduce a new model, open edge guards (excluding the endpoints of the edge), which we argue are in some sense more natural in this context. After quantifying the relationship between closed and open edge guards, we improve the upper bound to show that, asymptotically, (11/72)e (open or closed) edge guards …

Galaxy Browser: Exploratory Search Of Web Videos, Lei Pang, Song Tan, Hung-Khoon Tan, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

Most search engines return a ranked list of items in response to a query. The list however tells very little about the relationship among items. For videos especially, users often read to spend significant amount of time to navigate the search result. Exploratory search presents a new paradigm for browsing where the browser takes up the role of information exploring and presents a well-organized browsing structure for users to navigate. The proposed interface Galaxy Browser adopts the recent advances in near-duplicate detection and then synchronizes the detected near-duplicate information with comprehensive background knowledge derived from online external resources. The result …

Value Relevance Of Blog Visibility, Nan Hu, Ling Liu, Arindam Tripathy, Lee J. Yao

Research Collection School Of Computing and Information Systems

This study empirically examines the effect of a non-traditional information source, namely a firm's blog visibility on the capital market valuation of firms. After controlling for earnings, book value of equity and other value relevant variables, such as traditional media exposure, R&D spending, and advertising expense, we find a positive association between a firm's blog visibility and its capital market valuation. In addition, we find blog visibility Grange causes trading, not vice versa. Our findings indicate that non-traditional information sources such as blogs help disseminate information and influence consumers' investment decisions by capturing their attention.

Capir: Collaborative Action Planning With Intention Recognition, Nguyen T., Hsu D., Lee W., Tze-Yun Leong, Kaelbling L., Lozano-Perez T., Grant A.

Research Collection School Of Computing and Information Systems

We apply decision theoretic techniques to construct nonplayer characters that are able to assist a human player in collaborative games. The method is based on solving Markov decision processes, which can be difficult when the game state is described by many variables. To scale to more complex games, the method allows decomposition of a game task into subtasks, each of which can be modelled by a Markov decision process. Intention recognition is used to infer the subtask that the human is currently performing, allowing the helper to assist the human in performing the correct task. Experiments show that the method …

Localization Of Objects Using Cross-Correlation Of Shadow Fading Noise And Copulas, Mohammed Rana Basheer, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

While fading, in general, is detrimental to accurately localizing a target, fading correlation between adjacent receivers may be exploited to improve localization accuracy. Therefore, this paper presents a novel wireless localization scheme that employs a combination of cross-correlation between shadow fading noise and copula technique to recursively estimate the location of a transmitter. a stochastic filter that models multipath fading as an Ornstein-Uhlenbeck process followed by a Generalized Auto Regressive Conditional Heteroskedasticity (GARCH) filtering is proposed to extract shadow fading residuals from measured RSSI values. Subsequently, Student-t Copula function is used to create the log likelihood function, which acts as …

Network Covert Channels On The Android Platform, Wade Chester Gasior

Masters Theses and Doctoral Dissertations

Network covert channels are used to exfiltrate information from a secured environment in a way that is extremely difficult to detect or prevent. These secret channels have been identified as an important security threat to governments and the private sector, and several research efforts have focused on the design, detection, and prevention of such channels in enterprise-type environments. Mobile devices have become a ubiquitous computing platform, and are storing or have access to an increasingly large amount of sensitive information. As such, these devices have become prime targets of attackers who desire access to this information. In this work, we …

Relational Neighborhood Inverse Consistency For Constraint Satisfaction: A Structure-Based Approach For Adjusting Consistency And Managing Propagation, Robert J. Woodward

School of Computing: Dissertations, Theses, and Student Research

Freuder and Elfe [1996] introduced Neighborhood Inverse Consistency (NIC) as a local consistency property defined on the values in the variables' domains of a Constraint Satisfaction Problem (CSP). Debruyne and Bessiere [2011] showed that enforcing NIC on binary CSPs is ineffective on sparse graph and too costly on dense graphs. In this thesis, we propose Relational Neighborhood Inverse Consistency (RNIC), an extension of NIC defined as a local consistency property on the tuples of the relations of a CSP. We characterize RNIC for both binary and non-binary CSPs, and propose an algorithm for enforcing it whose complexity is bounded by …

Use Of Constraint Solving For Testing Software Product Lines, Jiangfan Shi

School of Computing: Dissertations, Theses, and Student Research

A new software engineering methodology, software product line (SPL) engineering, has been increasingly studied in academia and adopted inindustry in the past decade. It allows the delivery of similar, but customized, software products to customers in the same domain within a short timeperiod. Software product line engineering produces an SPL by defining feature commonality and variability, and is supported by a well-managed asset base. SPL engineering can improve productivity from three to ten times, however, we require more efficient testing methods, so that we canensure the correctness of SPLs with the same resource allocation percentage as in the traditional software …

Report On Advances In The Field Of Artificial Intelligence Attributed To Captcha, Craig M. Schow

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

A CAPTCHA is a specialized human interaction proof that exploits gaps between human and computer recognition abilities. By design, the hardness of a CAPTCHA is based on the difficulty of advancing the underlying artificial intelligence [AI] technology to a level that eliminates any exploitable gap. Due to this fact computer scientists have concluded that the widespread use of CAPTCHA would accelerate research in the underlying fields of AI eventually leading to near-­‐human capabilities in certain AI systems. Despite these predictions no attempt has been made to identify advances in AI which can be attributed to the use of CAPTCHA.

The …

Mahalanobis-Taguchi System As A Multi-Sensor Based Decision Making Prognostics Tool For Centrifugal Pump Failures, Ahmet Soylemezoglu, Sarangapani Jagannathan, Can Saygin

Electrical and Computer Engineering Faculty Research & Creative Works

A novel Mahalanobis Taguchi System (MTS) based fault detection, isolation, and prognostics scheme is presented. the proposed scheme fuses data from multiple sensors into a single system level performance metric using Mahalanobis Distance (MD) and generates fault clusters based on MD values. MD thresholds derived from the clustering analysis are used for fault detection and isolation. When a fault is detected, the prognostics scheme, which monitors the progression of the MD values over time, is initiated. Then, using a linear approximation, time to failure is estimated. the performance of the scheme has been validated via experiments performed on a mono-block …

Continuous Analysis Of Photocatalytic Activity In Thin-Films And Coatings, Steven Michael Allee

Master's Theses

Materials that undergo photocatalytic reactions create evolved gases due to ultraviolet light decomposition. Current methods of measuring these gases typically result in destruction of the sample. A test fixture was developed to measure evolved gases in a nondestructive manner through the utilization of a flow-through sensor array system. Preliminary testing indicates responsive measurements down to parts-per-billion sensitivity for some gases and will be compared with mass spectrometry measurements. Further development of this process could lead to the ability to measure photocatalytic reaction gases on a continuous basis without interruption of the process or destruction of materials introduced to the system.

Alignment-Free Methods And Its Applications, Ramez Mina

Student Work

Comparing biological sequences remains one of the most vital activities in Bioinformatics. Comparing biological sequences would address the relatedness between species, and find similar structures that might lead to similar functions.

Sequence alignment is the default method, and has been used in the domain for over four decades. It gained a lot of trust, but limitations and even failure has been reported, especially with the new generated genomes. These new generated genomes have bigger size, and to some extent suffer errors. Such errors come mainly as a result from the sequencing machine. These sequencing errors should be considered when submitting …

Vireo@Trecvid 2011: Instance Search, Semantic Indexing, Multimedia Event Detection And Known-Item Search, Chong-Wah Ngo, Shi-Ai Zhu, Wei Zhang, Chun-Chet Tan, Ting Yao, Lei Pang, Hung-Khoon Tan

Research Collection School Of Computing and Information Systems

The vireo group participated in four tasks: instance search, semantic indexing, multimedia event detection and known-item search. In this paper,we will present our approaches and discuss the evaluation results.

High Performance Geospatial Analysis On Emerging Parallel Architectures, Seth Warn

Graduate Theses and Dissertations

Geographic information systems (GIS) are performing increasingly sophisticated analyses on growing data sets. These analyses demand high performance. At the same time, modern computing platforms increasingly derive their performance from several forms of parallelism. This dissertation explores the available parallelism in several GIS-applied algorithms: viewshed calculation, image feature transform, and feature analysis. It presents implementations of these algorithms that exploit parallel processing to reduce execution time, and analyzes the effectiveness of the implementations in their use of parallel processing.

Design And Implementation Of An Open Framework For Ubiquitous Carbon Footprint Calculator Applications, Farzana Rahman, Casey O'Brien, Sheikh Iqbal Ahamed, He Zhang, Lin Liu

Mathematics, Statistics and Computer Science Faculty Research and Publications

As climate change is becoming an important global issue, more and more people are beginning to pay attention to reducing greenhouse gas emissions. To measure personal or household carbon dioxide emission, there are already plenty of carbon footprint calculators available on the web. Most of these calculators use quantitative models to estimate carbon emission caused by a user's activities. Although these calculators can promote public awareness regarding carbon emission due to an individual's behavior, there are concerns about the consistency and transparency of these existing CO₂ calculators. Apart from a small group of smart phone based carbon footprint calculator …

Automating Construction And Selection Of A Neural Network Using Stochastic Optimization, Jason Lee Hurt

UNLV Theses, Dissertations, Professional Papers, and Capstones

An artificial neural network can be used to solve various statistical problems by approximating a function that provides a mapping from input to output data. No universal method exists for architecting an optimal neural network. Training one with a low error rate is often a manual process requiring the programmer to have specialized knowledge of the domain for the problem at hand.

A distributed architecture is proposed and implemented for generating a neural network capable of solving a particular problem without specialized knowledge of the problem domain. The only knowledge the application needs is a training set that the network …

Consolidated Study On Query Expansion, Abhishek Biruduraju

UNLV Theses, Dissertations, Professional Papers, and Capstones

A typical day of million web users all over the world starts with a simple query. The quest for information on a particular topic drives them to search for it, and in the pursuit of their info the terms they supply for queries varies from person to person depending on the knowledge they have. With a vast collection of documents available on the web universe it is the onus of the retrieval system to return only those documents that are relevant and satisfy the user’s search requirements. The document mismatch problem is resolved by appending extra query terms to the …

Study Of Feature Selection Algorithms For Text-Categorization, Kandarp Dave

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis will discuss feature selection algorithms for text-categorization. Feature selection algorithms are very important, as they can make-or-break a categorization engine. The feature selection algorithms that will be discussed in this thesis are Document Frequency, Information Gain, Chi Squared, Mutual Information, NGL (Ng-Goh-Low) coefficient, and GSS (Galavotti-Sebastiani-Simi) coefficient . The general idea of any feature selection algorithm is to determine importance of words using some measure that can keep informative words, and remove non-informative words, which can then help the text-categorization engine categorize a document, D , into some category, C . These feature selection methods are explained, implemented, …

Sire: A Social Image Retrieval Engine, Steven C. H. Hoi, Pengcheng Wu

Research Collection School Of Computing and Information Systems

With the explosive growth of social media applications on the internet, billions of social images have been made available in many social media web sites nowadays. This has presented an open challenge of web-scale social image search. Unlike existing commercial web search engines that often adopt text based retrieval, in this demo, we present a novel web-based multimodal paradigm for large-scale social image retrieval, termed "Social Image Retrieval Engine" (SIRE), which effectively exploits both textual and visual contents to narrow down the semantic gap between high-level concepts and low-level visual features. A relevance feedback mechanism is also equipped to learn …

Validation Of A Model Of Information Systems User Competency, Brenda Eschenbrenner, Fiona Fui-Hoon Nah

Research Collection School Of Computing and Information Systems

IS user competency, or the ability to realize the fullest potential and the greatest performance from IS use, is important for IS users. However, which factors contribute to IS user competency is unclear. Based on the findings of previous research, a model of IS user competency was developed that focuses on IS-specific characteristics: (i) domain knowledge of and skills in IS, (ii) willingness to try and to explore IS, and (iii) capability of perceiving IS value. The model was validated using the survey approach and the findings suggest that all three factors are pivotal to IS user competency, with willingness …

Retrieval-Based Face Annotation By Weak Label Regularized Local Coordinate Coding, Dayong Wang, Steven C. H. Hoi, Ying He, Jianke Zhu

Research Collection School Of Computing and Information Systems

Retrieval-based face annotation is a promising paradigm in mining massive web facial images for automated face annotation. Such an annotation paradigm usually encounters two key challenges. The first challenge is how to efficiently retrieve a short list of most similar facial images from facial image databases, and the second challenge is how to effectively perform annotation by exploiting these similar facial images and their weak labels which are often noisy and incomplete. In this paper, we mainly focus on tackling the second challenge of the retrieval-based face annotation paradigm. In particular, we propose an effective Weak Label Regularized Local Coordinate …

Gender Differences In Virtual Collaboration On A Creative Design Task, Shu Schiller, Fiona Nah, Brian Mennecke, Keng Siau

Research Collection School Of Computing and Information Systems

Collaboration is an important activity in every organization because it fundamentally affects work processes and organizational outcomes. Diversity adds complexity to the mechanism of virtual teams because teams routinely operate virtually by spanning temporal, geographic, national, and cultural boundaries. One important way to decode such complexity is to understand gender differences and their impacts on virtual modes of collaboration. In this research, we examine gender differences and how they influence outcomes and attitudes on virtual collaboration in the context of team gender composition. Phase one of our study involved male-male dyads and female-female dyads that collaborated virtually in Second Life. …

The Valuation Of User-Generated Content: A Structural, Stylistic And Semantic Analysis Of Online Reviews, Noi Sian Koh

Dissertations and Theses Collection (Open Access)

The ability and ease for users to create and publish content has provided vast amount of online product reviews. However, the amount of data is overwhelmingly large and unstructured, making information difficult to quantify. This creates challenge in understanding how online reviews affect consumers’ purchase decisions. In my dissertation, I explore the structural, stylistic and semantic content of online reviews. Firstly, I present a measurement that quantifies sentiments with respect to a multi-point scale and conduct a systematic study on the impact of online reviews on product sales. Using the sentiment metrics generated, I estimate the weight that customers place …

Identifying Effort Estimation Factors For Corrective Maintenance In Object-Oriented Systems, Michael J. Lee

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research identifies factors that impact software maintenance effort by exploring the decision-making process of expert estimators of corrective maintenance projects by using qualitative methods to identify the factors that they use in deriving estimates. We implement a technique called causal mapping, which allows us to identify the cognitive links between the information that estimators use, and the estimates that they produce based on that information. Results suggest that a total of 17 factors may be relevant for corrective maintenance effort estimation, covering constructs related to developers, code, defects, and environment. When these factors are rank-ordered, they demonstrate that some …

Quantification Of Stochastic Uncertainty Propagation For Monte Carlo Depletion Methods In Reactor Analysis, Quentin Thomas Newell

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Monte Carlo method provides powerful geometric modeling capabilities for large problem domains in 3-D; therefore, the Monte Carlo method is becoming popular for 3-D fuel depletion analyses to compute quantities of interest in spent nuclear fuel including isotopic compositions. The Monte Carlo approach has not been fully embraced due to unresolved issues concerning the effect of Monte Carlo uncertainties on the predicted results.

Use of the Monte Carlo method to solve the neutron transport equation introduces stochastic uncertainty in the computed fluxes. These fluxes are used to collapse cross sections, estimate power distributions, and deplete the fuel within depletion …

Pedestrian Leadership And Egress Assistance Simulation Environment (Please), Kyle D. Feuz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pedestrian simulation models are used in many different applications including, the design of safer buildings, the validation of fire codes, and automatic video surveillance and tracking. By improving the simulation model used, each of the application areas can experience similar improvements in accuracy. Current simulation models fail to address key concerns in representing pedestrian knowledge and in accurately modeling group formation. This project has at its core the goal of bringing attention these areas of concern and providing an initial look at ways to solve these problems.

The Pedestrian Leadership and Egress Assistance Simulation Environment (PLEASE) is developed specifically to …

Rigging And Texturing Considerations For The Short Film Spider Fight, Casey Johnson

All Theses

This paper delves into two separate production areas of the short film, Spider Fight: the approach used to solve the problem of rigging eyelids for 3d characters, and the pipelines that were implemented for texturing 3d assets. Typically, problems exist in the rigging of eyelids for 3d characters. Productions rely on a series of blend shapes, or a combination of joints and blend shapes, to produce satisfactory eyelid movement. Spider Fight, however, used a series of curves and joints to control the movement of the eyelids, which allowed a high degree of control over eyelid movement, and also fast editing …

A Web-Integrated Environment For Component-Based Software Reasoning, Charles Cook

All Theses

This thesis presents the Web IDE, a web-integrated environment for component-based software reasoning. The Web IDE is specifically tailored to emphasize the relationships among various components in component-based software engineering (CBSE) and to facilitate reasoning. It allows students to use RESOLVE, a component-based, integrated specification and programming language, to build components and systems, providing real-time feedback that can be used to reason about the correctness of their component implementations. Real-time interaction and relationship focused component presentation reinforces CBSE and reasoning principles in a way not possible with traditional programming exercises and file management systems.
The Web IDE has gone through …