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Full-Text Articles in Physical Sciences and Mathematics
Access Control In And For The Real World, Sara Sinclair
Access Control In And For The Real World, Sara Sinclair
Dartmouth College Ph.D Dissertations
Access control is a core component of any information-security strategy. Researchers have spent tremendous energy over the past forty years defining abstract access-control models and proving various properties about them. However, surprisingly little attention has been paid to how well these models work in real socio-technical systems (i.e., real human organizations). This dissertation describes the results of two qualitative studies (involving 52 participants from four companies, drawn from the financial, software, and healthcare sectors) and observes that the current practice of access control is dysfunctional at best. It diagnoses the broken assumptions that are at the heart of this dysfunction, …
Grid Cryptographic Simulation: A Simulator To Evaluate The Scalability Of The X.509 Standard In The Smart Grid, Tucker L. Ward
Grid Cryptographic Simulation: A Simulator To Evaluate The Scalability Of The X.509 Standard In The Smart Grid, Tucker L. Ward
Dartmouth College Undergraduate Theses
PKI may be pushed beyond known limits when scaled to some visions of the smart grid; our research developed a simulation, Grid Cryptographic Simulation (GCS), to evaluate these potential issues, identify cryptographic bottlenecks, and evaluate tradeoffs between performance and security. Ultimately, GCS can be used to identify scalability challenges and suggest improvements to make PKI more efficient, effective, and scalable before it is deployed in the envisioned smart grid.
Usable Security For Wireless Body-Area Networks, Cory Cornelius
Usable Security For Wireless Body-Area Networks, Cory Cornelius
Dartmouth College Ph.D Dissertations
We expect wireless body-area networks of pervasive wearable devices will enable in situ health monitoring, personal assistance, entertainment personalization, and home automation. As these devices become ubiquitous, we also expect them to interoperate. That is, instead of closed, end-to-end body-worn sensing systems, we envision standardized sensors that wirelessly communicate their data to a device many people already carry today, the smart phone. However, this ubiquity of wireless sensors combined with the characteristics they sense present many security and privacy problems. In this thesis we describe solutions to two of these problems. First, we evaluate the use of bioimpedance for recognizing …
Please Take My Survey: Compliance With Smartphone-Based Ema/Esm Studies, Shloka R. Kini
Please Take My Survey: Compliance With Smartphone-Based Ema/Esm Studies, Shloka R. Kini
Dartmouth College Undergraduate Theses
This thesis analyzes the factors that affect compliance in Ecological Momentary Assessment (EMA) survey systems using smartphones. Current EMA systems have simple parameters in their triggering mechanisms, which results in missed or ignored surveys, creating a loss of subject data. Over the course of three user studies, with slight variations, we analyze the factors that influence the willingness of a survey participant to answer surveys on an Android phone. An understanding of these factors would be valuable for mobile developers in developing advanced EMA trigger systems. After having experienced various unforeseen challenges in the process, we describe the parameters and …
Nimbus A Novel Multi-Device Operating System Shell, Sang Jin Lee
Nimbus A Novel Multi-Device Operating System Shell, Sang Jin Lee
Dartmouth College Undergraduate Theses
Web technologies have advanced considerably in the last decade. With the introduction of HTML5 and CSS3 web standards, websites are no longer static documents, but rich applications that are capable of rivaling those written in native code. Similarly, internet infrastructure and adoption has reached a point where "always connected" and cross-platform applications such as Facebook, Twitter, Google Drive, Spotify, Dropbox, and Youtube are becoming dominant. While these web applications have acclimated users to cross-platform and cross-device experiences, operating systems have lagged behind, offering subpar experiences across devices. We present the design, prototype implementation, and evaluation of Nimbus, an operating system …
An Algorithm For Computing Edge Colorings On Regular Bipartite Multigraphs, Andrew S. Hannigan
An Algorithm For Computing Edge Colorings On Regular Bipartite Multigraphs, Andrew S. Hannigan
Dartmouth College Undergraduate Theses
In this paper, we consider the problem of finding an edge coloring of a d-regular bipartite multigraph with 2n vertices and m=nd edges. The best known deterministic algorithm (by Cole, Ost, and Schirra) takes O(m log d) time to find an edge coloring of such a graph. This bound is achieved by combining an O(m)-time perfect-matching algorithm with the Euler partition algorithm. The O(m) time bound on the Cole, Ost, and Schirra perfect-matching algorithm has been shown to be optimal. In this paper we present an alternative perfect-matching algorithm called QuickMatch. Empirical analysis shows that QuickMatch finds a perfect matching …
Ekho: A Tool For Recording And Emulating Energy Harvesting Conditions, Ryan H. Archer
Ekho: A Tool For Recording And Emulating Energy Harvesting Conditions, Ryan H. Archer
Dartmouth College Undergraduate Theses
Harvested energy makes it possible to deploy sensing devices long-term with minimal required upkeep. However, as devices shrink, unpredictable power supplies make it difficult for system designers to anticipate the behavior of these devices. Ekho is tool that records and emulates energy harvesting conditions in order to enable accurate and repeatable testing of these sensing devices. Ekho uses the concept of I-V curves — curves that describe harvesting current in relation to supply voltage — in order to accurately represent harvesting conditions in a form that is independent of the sensing platform and the type of energy that is being …
Mobile Applications: Games That Transform Education, Edward Y. Zhang
Mobile Applications: Games That Transform Education, Edward Y. Zhang
Dartmouth College Undergraduate Theses
A breakthrough development in the crossing of education and technology has long been a subject of heated debate. The possibility of combining machine learning and attention-grabbing graphics to not only make learning easy and interesting, but personalized, was the original impetus for gamifying education. In this paper I investigate the history of technology and media through the lens of education, and attempt to apply the principles, practices, and insights gleaned there within to an educational mobile game. Specifically, the mobile app I designed for the iPhone and Android operating systems focuses on teaching players SAT I math concepts using Nintendo’s …
Polynomial And Query Complexity Of Minterm-Cyclic Functions, Matthew J. Harding
Polynomial And Query Complexity Of Minterm-Cyclic Functions, Matthew J. Harding
Dartmouth College Undergraduate Theses
Boolean functions are at the heart of all computations, and all Boolean functions can be reduced to a sum of pattern-matching functions, called minterm-cyclic functions. In this thesis, we examine properties of polynomials representing minterm-cyclic Boolean functions. We use the term "saturated" to represent a polynomial with degree equal to input size n for all n; this indicates the intuitive notion that such functions are in some way complex, or difficult to compute. We present three main results. Firstly, there exist an infinite number of monotone minterm-cyclic functions that are not saturated. Secondly, for a specific class of minterms called …
Sampling For Complexity In Rendering, Jiawei Ou
Sampling For Complexity In Rendering, Jiawei Ou
Dartmouth College Ph.D Dissertations
As the visual effect and movie industries are striving for realism and high fidelity images, physically based lighting, global illumination, realistic materials, and highly tessellated geometry are gradually accepted and used in movie and game industries. Modern computer graphics has reached an unprecedented level of complexity. As a result, brute-force rendering methods become prohibitively expensive. For decades, computer graphics researchers have been tackling the complexity in rendering by introducing more advanced Monte Carlo integrators, efficient sampling and reconstruction algorithms, effective filtering techniques, sophisticated data structures, and new hardware architectures. In this thesis, we focus on deriving better sampling algorithms to …
Geometrical And Probabilistic Methods For Determining Association Models And Structures Of Protein Complexes, Himanshu Chandola
Geometrical And Probabilistic Methods For Determining Association Models And Structures Of Protein Complexes, Himanshu Chandola
Dartmouth College Ph.D Dissertations
Protein complexes play vital roles in cellular processes within living organisms. They are formed by interactions between either different proteins (hetero-oligomers) or identical proteins (homo-oligomers). In order to understand the functions of the complexes, it is important to know the manner in which they are assembled from the component subunits and their three dimensional structure. This thesis addresses both of these questions by developing geometrical and probabilistic methods for analyzing data from two complementary experiment types: Small Angle Scattering (SAS) and Nuclear Magnetic Resonance (NMR) spectroscopy. Data from an SAS experiment is a set of scattering intensities that can give …
Photo Forensics From Partial Constraints, Eric R. Kee
Photo Forensics From Partial Constraints, Eric R. Kee
Dartmouth College Ph.D Dissertations
A variety of forensic methods have been developed to identify falsified photos, each unified by the ability to estimate and detect properties of a photo that are perturbed by forgery. There exist, however, many photos in which the required properties cannot be estimated. We present an approach to detect forgery in these photos. We use this approach to detect physically inconsistent shadows and shading in photos for which it is not possible to estimate the associated lighting properties. Specifically, we develop a method to detect inconsistent shadows cast by point and area light sources when a strict shadow-to-object correspondence cannot …
Security-Policy Analysis With Extended Unix Tools, Gabriel A. Weaver
Security-Policy Analysis With Extended Unix Tools, Gabriel A. Weaver
Dartmouth College Ph.D Dissertations
During our fieldwork with real-world organizations---including those in Public Key Infrastructure (PKI), network configuration management, and the electrical power grid---we repeatedly noticed that security policies and related security artifacts are hard to manage. We observed three core limitations of security policy analysis that contribute to this difficulty. First, there is a gap between policy languages and the tools available to practitioners. Traditional Unix text-processing tools are useful, but practitioners cannot use these tools to operate on the high-level languages in which security policies are expressed and implemented. Second, practitioners cannot process policy at multiple levels of abstraction but they need …