Computer Sciences Commons^™

Nanoscale Frictional Properties Of Nickel With One-Dimensional And Two-Dimensional Materials, Timothy K. Schlenger

Mechanical Engineering Undergraduate Honors Theses

When looking at the nanoscale, material interface interactions have been observed to exhibit particularly interesting properties. Our research looks into various combinations of carbyne and graphene atop a nickel block to look into the interface friction properties between them. Both the carbyne and graphene are tested using steered molecular dynamics (SMD) in sheering and peeling directions along the surface of the nickel block. These tests are then analyzed by comparing the magnitude of the acting force versus the displacement of the carbon allotrope sample across the nickel block. It is found that as the width of a carbon allotrope sample …

Enabling Usage Pattern-Based Logical Status Inference For Mobile Phones, Jon C. Hammer

Graduate Theses and Dissertations

Logical statuses of mobile users, such as isBusy and isAlone, are the key enabler for a plethora of context-aware mobile applications. While on-board hardware sensors (such as motion, proximity, and location sensors) have been extensively studied for logical status inference, continuous usage typically requires formidable energy consumption, which degrades the user experience. In this thesis, we argue that smartphone usage statistics can be used for logical status inference with negligible energy cost. To validate this argument, we present a continuous inference engine that (1) intercepts multiple operating system events, in particular foreground app, notifications, screen states, and connected networks; (2) …

Enabling Runtime Profiling To Hide And Exploit Heterogeneity Within Chip Heterogeneous Multiprocessor Systems (Chmps), Eugene Cartwright

Graduate Theses and Dissertations

The heterogeneity of multiprocessor systems on chip (MPSoC) has presented unique opportunities for furthering today’s diverse application needs. FPGA-based MPSoCs have the potential of bridging the gap between generality and specialization but has traditionally been limited to device experts. The flexibility of these systems can enable computation without compromise but can only be realized if this flexibility extends throughout the software stack. At the top of this stack, there has been significant effort for leveraging the heterogeneity of the architecture. However, the betterment of these abstractions are limited to what the bottom of the stack exposes: the runtime system.

The …

Sonifying Git History, Kevin J. North

School of Computing: Dissertations, Theses, and Student Research

Version control is a technique that software developers use in industry to manage their source code artifacts. One benefit of using version control is that it produces a history of every change made to a codebase, which developers frequently analyze in order to aid the software development process. However, version control history contains highly multidimensional and temporal data. State of the art techniques can show several of these dimensions, but they cannot show a large number of dimensions simultaneously without becoming difficult to understand. An alternative technique to understand temporal data with high dimensionality is sonification. Sonification maps information to …

The Impact Of Cues And User Interaction On The Memorability Of System-Assigned Random Passwords, Mahdi Nasrullah Al Ameen

Computer Science and Engineering Dissertations - Archive

Given the choice, users produce passwords reflecting common strategies and patterns that ease recall but offer uncertain and often weak security. Addressing this usability-security tension in user authentication remains the key research issue in password studies for decades. In this thesis, we aim to understand how humans' cognitive abilities could be leveraged to design more secure and memorable authentication schemes. To achieve this goal, we draw upon multiple theories from cognitive psychology and implement them in the context of improving memorability for system-assigned random passwords. We argue that while the system assigns random passwords, it should also help users with …

An Exploration Of The Effectiveness Of The Use Of Communication Apps Through Mobile Devices On Children With Autism Spectrum Disorders (Asd), Miriam O Sullivan

Theses

Autism Spectrum Disorder (ASD) is a complex neurological disorder which impacts on people in three primary areas: communication skills, social skills and behaviour skills. The diagnosis of ASD continues to rise with an estimated 1 in 100 receiving diagnoses of ASD in Ireland. There are many interventions promoted on a regular basis that claim positive effects on the basis of empirical research. However, the claims made by such studies are sometimes a little at odds with the level of methodological rigour and/or sample size employed. The research available is based on small scale international studies (America, Canada and Australia); however, …

Principles Of Anti-Discriminatory Design, D. E. Wittkower

Philosophy Faculty Publications

Technical design can produce exclusionary and even discriminatory effects for users. A lack of discriminatory intent is insufficient to avoid discriminatory design, since implicit assumptions about users rarely include all relevant user demographics, and in some cases, designing for all relevant users is actually impossible. To minimize discriminatory effects of technical design, an actively anti-discriminatory design perspective must be adopted. This article provides examples of discriminatory user exclusion, then defining exclusionary design in terms of disaffordances and dysaffordances. Once these definitions are in place, principles of anti-discriminatory design are advanced, drawing upon a method of phenomenological variation employed in the …

Self-Monitoring Practices, Attitudes, And Needs Of Individuals With Bipolar Disorder: Implications For The Design Of Technologies To Manage Mental Health, Elizabeth L. Murnane, Dan Cosley, Pamara Chang, Shion Guha, Ellen Frank, Geri K. Gay, Mark Matthews

Mathematics, Statistics and Computer Science Faculty Research and Publications

Objective To understand self-monitoring strategies used independently of clinical treatment by individuals with bipolar disorder (BD), in order to recommend technology design principles to support mental health management.

Materials and Methods Participants with BD (N = 552) were recruited through the Depression and Bipolar Support Alliance, the International Bipolar Foundation, and WeSearchTogether.org to complete a survey of closed- and open-ended questions. In this study, we focus on descriptive results and qualitative analyses.

Results Individuals reported primarily self-monitoring items related to their bipolar disorder (mood, sleep, finances, exercise, and social interactions), with an increasing trend towards the use of digital …

Barriers To Initiation Of Open Source Software Projects In Research Libraries, Jason Curtis Thacker

Theses and Dissertations

Libraries share a number of core values with the Open Source Software (OSS) movement, suggesting there should be a natural tendency toward library participation in OSS projects. However, Dale Askey's 2008 Code4Lib column entitled We Love Open Source Software. No, You Can't Have Our Code, claims that while libraries are strong proponents of OSS, they are unlikely to actually contribute to OSS projects. He identifies, but does not empirically substantiate, six barriers that he believes contribute to this apparent inconsistency. The goal of this thesis is to empirically investigate not only Askey's central claim but also the six barriers he …

Intelligent Pen: A Least Cost Search Approach To Stroke Extraction In Historical Documents, Kevin L. Bauer

Theses and Dissertations

Extracting strokes from handwriting in historical documents provides high-level features for the challenging problem of handwriting recognition. Such handwriting often contains noise, faint or incomplete strokes, strokes with gaps, overlapping ascenders and descenders and competing lines when embedded in a table or form, making it unsuitable for local line following algorithms or associated binarization schemes. We introduce Intelligent Pen for piece-wise optimal stroke extraction. Extracted strokes are stitched together to provide a complete trace of the handwriting. Intelligent Pen formulates stroke extraction as a set of piece-wise optimal paths, extracted and assembled in cost order. As such, Intelligent Pen is …

An Analyzer For Message Passing Programs, Yu Huang

Theses and Dissertations

Asynchronous message passing systems are fast becoming a common means for communication between devices. Two problems existing in message passing programs are difficult to solve. The first problem, intended or otherwise, is message-race where a receive may match with more than one send in the runtime system. This non-determinism often leads to intermittent and unexpected behavior depending on the resolution of the race. Another problem is deadlock, which is a situation in that each member process of the group is waiting for some member process to communicate with it, but no member is attempting to communicate with it. Detecting if …

Graphical Narrative Interfaces: Representing Spatiotemporal Information For A Human-Robot Team With A Highly Autonomous Robot, Hiroaki Nakano

Theses and Dissertations

Having a well-developed Graphical User Interface (GUI) is often necessary for a human-robot team, especially when the human and the robot are not in close proximity to each other or when the human does not interact with the robot in real time. Most current GUIs process and display information in real time, but the time to interact with these systems does not scale well when the complexity of the displayed information increases or when information must be fused to support decision-making. We propose a new interface concept, a Graphical Narrative Interface (GNI), which presents story-based summaries driven by accumulated data. …

Enhancing Snort Ids Performance Using Data Mining, Mohammed Ali Almaleki

Theses

Intrusion detection systems (IDSs) such as Snort apply deep packet inspection to detect intrusions. Usually, these are rule-based systems, where each incoming packet is matched with a set of rules. Each rule consists of two parts: the rule header and the rule options. The rule header is compared with the packet header. The rule options usually contain a signature string that is matched with packet content using an efficient string matching algorithm. The traditional approach to IDS packet inspection checks a packet against the detection rules by scanning from the first rule in the set and continuing to scan all …

Toward Dmd Illuminated Spatial-Temporal Modulated Thermography, Joshua D. Pribe, Srinivas Chakravarthi Thandu, Zhaozheng Yin, Edward C. Kinzel

Computer Science Faculty Research & Creative Works

This paper reports on a system using a Digital Micromirror Device (DMD) to modulate a near-infrared laser source spatially and temporally. The DMD can produce an arbitrary heat source varying both spatially and temporally over the target. When the thermal response of the target surface is recorded using a thermal imager, this provides new possibilities in subsurface defect detection, partially with regard to features whose orientation does not allow them to be resolved using conventional thermographic inspection techniques. In this respect it is similar to conventional focused spot detection approaches; however, the DMD allows the signal to be frequency/phase multiplexed …

Zephyr: A Social Psychology-Based Mobile Application For Long-Distance Romantic Partners, Dhiraj Bodicherla

Open Access Theses

Long-distance romantic relationships have become quite common nowadays. With CMC tools advancing day-by-day, their usage among LDRs is proliferating rapidly. Attachment-related anxiety and avoidance can block the ability to enjoy happy relationships. During such situations, remembering happy past moments can be comforting. In this study a mobile chat application that enables LDR couples to reminisce about happy moments was developed. This study primarily focuses on evaluating the usability of this mobile application using survey-based methods. System Usability Scale was considered to discuss the outcome of the study. The overall results provide useful recommendations for further improvements in the design of …

An Exploratory Study Of High Performance Graphics Application Programming Interfaces, Joseph A. Shiraef

Masters Theses and Doctoral Dissertations

This study was conducted to take an in depth look at the newest APIs offered to graphics programmers. With the recent releases of Vulkan (2016) and DirectX 12 (2015) from industry giants like the Khronos Group and Microsoft, it’s clear they are pushing for a much lower-level, closer-to-hardware approach for future graphics programming solutions. These changes can be credited to the drastic improvements we’ve seen in graphics processors over the last 5 years. It will take a significant amount of time for these API’s to become industry standard. The goal of this research is to verify the value and benefits …

Algorithmic Problems Arising In Posets And Permutations, Shahrzad Haddadan

Dartmouth College Ph.D Dissertations

Partially ordered sets and permutations are combinatorial structures having vast applications in theoretical computer science. In this thesis, we study various computational and algorithmic problems related to these structures. The first chapter of the thesis contains discussion about randomized fully polynomial approximation schemes obtained by employing Markov chain Monte Carlo. In this chapter we study various Markov chains that we call: the gladiator chain, the interval chain, and cube shuffling. Our objective is to identify some conditions that assure rapid mixing; and we obtain partial results. The gladiator chain is a biased random walk on the set of permutations. This …

Constraint-Based Robot Knot Tying, Weifu Wang

Dartmouth College Ph.D Dissertations

In this thesis, we present different approaches to tying knots using robots by enforcing different types of constraints. We attack the problem from three different directions; mechanical design, motion planning with simple control strategies, and theoretical analysis. We present the first complete generalized fixture based knot tying approach that is able to arrange and tighten knots, building on Matthew Bell’s work on arranging simple knots using fixtures [Bel10]. Physical constraints are provided by these fixtures to reduce the possible string deformation during knot tying. Fixtures are designed automatically using proposed design principles, and constructed based on the designs using 3D …

The Eagle Programming Language, Samuel G. Horlbeck Olsen

Mathematics, Statistics, and Computer Science Honors Projects

C remains the dominant systems programming language despite many new languages attempting to take its place. Modern languages generally value abstraction and safety over speed and direct control of hardware. They are therefore not well suited to the low-level tasks for which C was designed. This paper introduces a novel programming language, Eagle, which represents a fast, elegant alternative to C. It allows low-level programming while providing optional modern features like reference counting, closures, generators, and classes. In addition to specifying this language and reviewing the current alternatives, the paper describes the implementation of a working Eagle compiler. The language …

Bases For Mckay Centralizer Algebras, Lucas Gagnon

Mathematics, Statistics, and Computer Science Honors Projects

The finite subgroups of the special unitary group SU2 have been classified to be isomorphic to one of the following groups: cyclic, binary dihedral, binary tetrahedral, binary octahedral, and binary icosahedral, of order n, 4n, 24, 48, and 120, respectively. Associated to each group is a representation graph, which by the McKay correspondence is a Dynkin diagram of type Aˆ n−1, Dˆ n+2, Eˆ 6, Eˆ 7, or Eˆ 8. The centralizer algebra Zk(G) = EndG(V ⊗k ) is the algebra of transformations that commute with G acting on the k-fold tensor product of the defining representation V = C …

Building Voters: Exploring Interdependent Preferences In Binary Contexts, Ian Calaway

Mathematics, Statistics, and Computer Science Honors Projects

In this thesis we develop a new method for constructing binary preference orders for given interdependent structures, called characters. We introduce the preference space, which is a vector space of preference vectors. The preference vectors correspond to binary preference orders. We show that the hyperoctahedral group, Z2 o Sn, describes the symmetries of binary preferences orders and then define an action of Z2 o Sn on our preference vectors. We find a natural basis for a preference space. These basis vectors are indexed by subsets of proposals. We show that when completely separable binary preference vectors are decomposed using this …

A Comparative Approach To Question Answering Systems, Josue Balandrano Coronel

Theses and Dissertations

In this paper I will analyze three different algorithms and approaches to implement Question Answering Systems (QA-Systems). I will analyze the efficiency, strengths, and weaknesses of multiple algorithms by explaining them in detail and comparing them with each other. The overarching aim of this thesis is to explore ideas that can be used to create a truly open context QA-System. Open context QA-Systems remain an open problem.

The various algorithms and approaches presented in this work will be focused on complex questions. Complex questions are usually verbose and the context of the question is equally important to answer the query …

Global Entropy Based Greedy Algorithm For Discretization, Sai Jyothsna Jonnalagadda

Theses and Dissertations

Discretization algorithm is a crucial step to not only achieve summarization of continuous attributes but also better performance in classification that requires discrete values as input. In this thesis, I propose a supervised discretization method, Global Entropy Based Greedy algorithm, which is based on the Information Entropy Minimization. Experimental results show that the proposed method outperforms state of the art methods with well-known benchmarking datasets. To further improve the proposed method, a new approach for stop criterion that is based on the change rate of entropy was also explored. From the experimental analysis, it is noticed that the threshold based …

Analysis And Simulation Of A Social Network, Twitter: A Case Study, Jonatan Reyes

Theses and Dissertations

The use of online social networks empowers its users to efficiently disseminate information across traditional social networks. Typically, the weight and value of messages are relative to its readers’ culture and interests. Nevertheless, in some instances, messages take the form of viral phenomenon, which circulates around the world in very short periods of time. Therefore, despite the actual content of the message spread over the network, the determination of the effectiveness of message dissemination across the social network becomes an attractive opportunity for scientific study. Since a meticulous analysis of a complete online social network would require the acquisition of …

The Social Side Of Software Platform Ecosystems, Cleidson R. B. Da Souza, Fernando Figueira Filho, Müller Miranda, Renato Pina Ferreira, Christoph Treude, Leif Singer

Research Collection School Of Computing and Information Systems

Software ecosystems as a paradigm for large-scale software development encompass a complex mix of technical, business, and social aspects. While significant research has been conducted to understand both the technical and business aspects, the social aspects of software ecosystems are less well understood. To close this gap, this paper presents the results of an empirical study aimed at understanding the influence of social aspects on developers’ participation in software ecosystems. We conducted 25 interviews with mobile software developers and an online survey with 83 respondents from the mobile software development community. Our results point out a complex social system based …

Towards Secure Online Distribution Of Multimedia Codestreams, Swee Won Lo

Dissertations and Theses Collection (Open Access)

Multimedia codestreams distributed through open and insecure networks are subjected to attacks such as malicious content tampering and unauthorized accesses. This dissertation first addresses the issue of authentication as a mean to integrity - protect multimedia codestreams against malicious tampering. Two cryptographic-based authentication schemes are proposed to authenticate generic scalable video codestreams with a multi-layered structure. The first scheme combines the salient features of hash-chaining and double error correction coding to achieve loss resiliency with low communication overhead and proxy-transparency. The second scheme further improves computation cost by replacing digital signature with a hash-based message authentication code to achieve packet-level …

An Arithmetic-Based Deterministic Centroid Initialization Method For The K-Means Clustering Algorithm, Matthew Michael Mayo

Theses and Dissertations

One of the greatest challenges in k-means clustering is positioning the initial cluster centers, or centroids, as close to optimal as possible, and doing so in an amount of time deemed reasonable. Traditional fc-means utilizes a randomization process for initializing these centroids, and poor initialization can lead to increased numbers of required clustering iterations to reach convergence, and a greater overall runtime. This research proposes a simple, arithmetic-based deterministic centroid initialization method which is much faster than randomized initialization. Preliminary experiments suggest that this collection of methods, referred to herein as the sharding centroid initialization algorithm family, often outperforms random …

An Exploration Of Rule Clustering In Cellular Automata Rule Spaces, Jordon Huffman

Theses and Dissertations

The study of complex systems examines the global behavior of a system and how the individual parts of the system affect that behavior [1]. The study of complex systems spans across many fields of science like biology, physics, engineering, and computer science. One area of complex systems that has not been fully explored is cellular automata. Since its discovery by John von Neumann, there have been no consistent ways of categorizing similarities between cellular automata rules or collecting similar rules for observation. This thesis introduces an approach to identifying clusters of similar rules and extracting rules from that cluster. Several …

Sparse Feature Learning For Image Analysis In Segmentation, Classification, And Disease Diagnosis., Ehsan Hosseini-Asl

Electronic Theses and Dissertations

The success of machine learning algorithms generally depends on intermediate data representation, called features that disentangle the hidden factors of variation in data. Moreover, machine learning models are required to be generalized, in order to reduce the specificity or bias toward the training dataset. Unsupervised feature learning is useful in taking advantage of large amount of unlabeled data, which is available to capture these variations. However, learned features are required to capture variational patterns in data space. In this dissertation, unsupervised feature learning with sparsity is investigated for sparse and local feature extraction with application to lung segmentation, interpretable deep …

Teaching Numerical Methods In The Context Of Galaxy Mergers, Maria Kourjanskaia

Physics

Methods of teaching numerical methods to solve ordinary differential equations in the context of galaxy mergers were explored. The research published in a paper by Toomre and Toomre in 1972 describing the formation of galactic tails and bridges from close tidal interactions was adapted into a project targeting undergraduate physics students. Typically undergraduate physics students only take one Computational Physics class in which various techniques and algorithms are taught. Although it is important to study computational physics techniques, it is just as important to apply this knowledge to a problem that is representative of what computational physics researchers are investigating …