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Full-Text Articles in Physical Sciences and Mathematics
Methods Of Computing Deque Sortable Permutations Given Complete And Incomplete Information, Daniel J. Denton
Methods Of Computing Deque Sortable Permutations Given Complete And Incomplete Information, Daniel J. Denton
Dartmouth College Undergraduate Theses
The problem of determining which permutations can be sorted using certain switchyard networks is a venerable problem in computer science dating back to Knuth in 1968. In this work, we are interested in permutations which are sortable on a double-ended queue (called a deque), or on two parallel stacks. In 1982, Rosenstiehl and Tarjan presented an O(n) algorithm for testing whether a given permutation was sortable on parallel stacks. In the same paper, they also presented a modification giving O(n) test for sortability on a deque. We demonstrate a slight error in the version of their algorithm for testing deque …
Abortable Reader-Writer Locks Are No More Complex Than Abortable Mutex Locks, Zhiyu Liu
Abortable Reader-Writer Locks Are No More Complex Than Abortable Mutex Locks, Zhiyu Liu
Dartmouth College Master’s Theses
When a process attempts to acquire a mutex lock, it may be forced to wait if another process currently holds the lock. In certain applications, such as real-time operating systems and databases, indefinite waiting can cause a process to miss an important deadline. Hence, there has been research on designing abortable mutual exclusion locks, and fairly efficient algorithms of O(log n) RMR complexity have been discovered (n denotes the number of processes for which the algorithm is designed). The abort feature is just as important for a reader-writer lock as it is for a mutual exclusion lock, but to the …
Search For Trust: An Analysis And Comparison Of Ca System Alternatives And Enhancements, Alexandra C. Grant
Search For Trust: An Analysis And Comparison Of Ca System Alternatives And Enhancements, Alexandra C. Grant
Dartmouth College Undergraduate Theses
The security of the Public Key Infrastructure has been reevaluated in response to Certification Authority (CA) compromise which resulted in the circulation of fraudulent certificates. These rogue certificates can and have been used to execute Man-in-the-Middle attacks and gain access to users’ sensitive information. In wake of these events, there has been a call for change to the extent of either securing the current system or altogether replacing it with an alternative design. This paper will explore the following proposals which have been put forth to replace or improve the CA system with the goal of aiding in the prevention …
Constructing Simplicial Complexes Over Topological Spaces, Milka N. Doktorova
Constructing Simplicial Complexes Over Topological Spaces, Milka N. Doktorova
Dartmouth College Master’s Theses
The first step in topological data analysis is often the construction of a simplicial complex. This complex approximates the lost topology of a sampled point set. Current techniques often assume that the input is embedded in a metric -- often Euclidean -- space, and make significant use of the underlying geometry for efficient computation. Consequently, these techniques do not extend to non-Euclidean or non-metric spaces. In this thesis, we present an oracle-based framework for constructing simplicial complexes over arbitrary topological spaces. The framework consists of an oracle and an algorithm that builds the simplicial complex by making calls to the …
Asymptotic Statistics Of Nodal Domains Of Quantum Chaotic Billiards In The Semiclassical Limit, Kyle T. Konrad
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 …
A Data Flow Tracker And Reference Monitor For Webkit And Javascriptcore, Andrew Bloomgarden
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.
Sensor-Based System For Verifying Blood-Pressure Measurement Position, Emma N. Smithayer
Sensor-Based System For Verifying Blood-Pressure Measurement Position, Emma N. Smithayer
Dartmouth College Undergraduate Theses
Mobile maternal-health programs send workers door to door to visit pregnant women in rural India and collect data such as blood pressure or weight, then send that data to doctors for review. Since the doctors do not see the data collection, ensuring correct collection methods is crucial to allow them to make good treatment decisions. However, blood-pressure measurements are sometimes taken with the patient’s arm in the wrong position, which can cause inaccurate readings. This paper describes a system consisting of an automatic blood pressure cuff with an accelerometer and force sensors attached to determine whether the arm is at …
Exposing Privacy Concerns In Mhealth Data Sharing, Aarathi Prasad
Exposing Privacy Concerns In Mhealth Data Sharing, Aarathi Prasad
Dartmouth College Master’s Theses
Mobile health (mHealth) has become important in the field of healthcare information technology, as patients begin to use mobile devices to record their daily activities and vital signs. These devices can record personal health information even outside the hospital setting, while the patients are at home or at their workplace. However, the devices might record sensitive information that might not be relevant for medical purposes and in some cases may be misused. Patients need expressive privacy controls so that they can trade potential health benefits of the technology with the privacy risks. To provide such privacy controls, it is important …