Engineering Commons^™

Detecting The Presence Of Electronic Devices In Smart Homes Using Harmonic Radar, Beatrice Perez, Gregory Mazzaro, Timothy J. Pierson, David Kotz

Dartmouth Scholarship

Data about users is collected constantly by phones, cameras, Internet websites, and others. The advent of so-called ‘Smart Things' now enable ever-more sensitive data to be collected inside that most private of spaces: the home. The first step in helping users regain control of their information (inside their home) is to alert them to the presence of potentially unwanted electronics. In this paper, we present a system that could help homeowners (or home dwellers) find electronic devices in their living space. Specifically, we demonstrate the use of harmonic radars (sometimes called nonlinear junction detectors), which have also been used in …

Using Natural Language Processing And Sentiment Analysis To Augment Traditional User-Centered Design: Development And Usability Study, Curtis L. Petersen, Ryan Halter, David Kotz, Lorie Loeb, Summer B. Cook, Dawna M. Pidgeon, Brock Christensen, John A. Batsis

Dartmouth Scholarship

Background: Sarcopenia, defined as the age-associated loss of muscle mass and strength, can be effectively mitigated through resistance-based physical activity. With compliance at approximately 40% for home-based exercise prescriptions, implementing a remote sensing system would help patients and clinicians to better understand treatment progress and increase compliance. The inclusion of end users in the development of mobile apps for remote-sensing systems can ensure that they are both user friendly and facilitate compliance. With advancements in natural language processing (NLP), there is potential for these methods to be used with data collected through the user-centered design process.

Objective: This study aims …

Cup-Net: Compressed Ultrafast Photography Using Convolutional Neural Networks, Matthew Parker

ENGS 88 Honors Thesis (AB Students)

Compressed ultrafast photography (CUP) is a cutting-edge imaging technique that uses a variation of the traditional streak camera to obtain video at 100 billion frames per second with a single exposure. In order to achieve this level of temporal detail, CUP leverages compressed sensing (CS). Compressed sensing theory states that a compressed representation of an image can be directly acquired using a non-adaptive measurement matrix so long as the encoding matrix follows certain properties such as restrictive isometry and incoherence. This compressed representation of the original scene can later be reconstructed back into the original form. CUP applies CS by …

Abso2luteu-Net: Tissue Oxygenation Calculation Using Photoacoustic Imaging And Convolutional Neural Networks, Kevin Hoffer-Hawlik, Geoffrey P. Luke

ENGS 88 Honors Thesis (AB Students)

Photoacoustic (PA) imaging uses incident light to generate ultrasound signals within tissues. Using PA imaging to accurately measure hemoglobin concentration and calculate oxygenation (sO₂) requires prior tissue knowledge and costly computational methods. However, this thesis shows that machine learning algorithms can accurately and quickly estimate sO₂. absO₂luteU-Net, a convolutional neural network, was trained on Monte Carlo simulated multispectral PA data and predicted sO₂ with higher accuracy compared to simple linear unmixing, suggesting machine learning can solve the fluence estimation problem. This project was funded by the Kaminsky Family Fund and the Neukom Institute.

Indutivo: Contact-Based, Object-Driven Interactions With Inductive Sensing, Jun Gong, Xin Yang, Teddy Seyed, Josh Urban Davis, Xing-Dong Yang

Dartmouth Scholarship

We present Indutivo, a contact-based inductive sensing technique for contextual interactions. Our technique recognizes conductive objects (metallic primarily) that are commonly found in households and daily environments, as well as their individual movements when placed against the sensor. These movements include sliding, hinging, and rotation. We describe our sensing principle and how we designed the size, shape, and layout of our sensor coils to optimize sensitivity, sensing range, recognition and tracking accuracy. Through several studies, we also demonstrated the performance of our proposed sensing technique in environments with varying levels of noise and interference conditions. We conclude by presenting demo …

Phasorsec: Protocol Security Filters For Wide Area Measurement Systems, Prashant Anantharaman, Kartik Palani, Rafael Brantley, Sergey Bratus, Sean W. Smith

Dartmouth Scholarship

The addition of synchrophasors to the power grid to improve observability comes at the cost of an increased attack surface: the wide area measurement system. A common source of zero-days, that can be used to exploit the system, is improper input validation. The strict availability and timing requirements of the grid make it critical that input validation be done right and in a timely fashion. PhasorSec is a hardened security filter for the synchrophasor communication protocol, C37.118. PhasorSec is built using language theoretic principles which treat all input as a language with a specific grammar that defines what input must …

Battery-Free Eye Tracker On Glasses, Tianxing Li, Xia Zhou

Dartmouth Scholarship

This paper presents a battery-free wearable eye tracker that tracks both the 2D position and diameter of a pupil based on its light absorption property. With a few near-infrared (NIR) lights and photodiodes around the eye, NIR lights sequentially illuminate the eye from various directions while photodiodes sense spatial patterns of reflected light, which are used to infer pupil’s position and diameter on the fly via a lightweight inference algorithm. The system also exploits characteristics of different eye movement stages and adjusts its sensing and computation accordingly for further energy savings. A prototype is built with off-the-shelf hardware components and …

Improving Structure Mcmc For Bayesian Networks Through Markov Blanket Resampling, Chengwei Su, Mark E. Borsuk

Dartmouth Scholarship

Algorithms for inferring the structure of Bayesian networks from data have become an increasingly popular method for uncovering the direct and indirect influences among variables in complex systems. A Bayesian approach to structure learning uses posterior probabilities to quantify the strength with which the data and prior knowledge jointly support each possible graph feature. Existing Markov Chain Monte Carlo (MCMC) algorithms for estimating these posterior probabilities are slow in mixing and convergence, especially for large networks. We present a novel Markov blanket resampling (MBR) scheme that intermittently reconstructs the Markov blanket of nodes, thus allowing the sampler to more effectively …

Finding Largest Empty Circles With Location Constraints, L Paul Chew, Robert L. Scot Drysdale

Computer Science Technical Reports

Let S be a set of n points in the plane and let CH(S) represent the convex hull of S. The Largest Empty Circle (LEC) problem is the problem of finding the largest circle centered with CH(S) such that no point of S lies within the circle. Shamos and Hoey (SH75) outlined an algorithm for solving this problem in time O(n log n) by first computing the Voronoi diagram, V(S), in time O(n log n), then using V(S) and CH(S) to compute the largest empty circle in time O(n). In a recent paper [Tou83], Toussaint pointed out some problems with …

The Pairwise Intersection Problem For Monotone Polygons, David B. Levine

Computer Science Technical Reports

Geometric intersection problems arise in a number of areas of computer science including graphics and VLSI design rule checking. Previous work has concentrated on solving the pairwise intersection problem for line segments and iso-oriented rectangles. This thesis extends that work by presenting efficient algorithms to solve the pairwise intersection problem for monotone polygons. For general segments, the problem has been solved in O(N+I)*logN) time using a sweeping line technique, where N is the number of segments and I is the number of intersections reported. We combine this technique with approaches taken to solve the iso-oriented rectangle problem to yield an …

Producing Software Using Tools In A Workstation Environment, Mark Sherman, Robert L. Scot Drysdale

Computer Science Technical Reports

We discuss how we taught students to build and use translation, interpretive, editing and monitoring tools in an undergraduate software engineering course. Students used the tools on low-cost workstations (Macintoshes) to build large, group projects. The students' projects used all available features of workstation environments, including graphics, windows, fonts, mice, networks, and sound generators. We found that 1) the use of tools increased student productivity, 2) a shift in a data structure and algorithm topics is needed to cover material relevant for workstation environments, 3) new topics in system design are required for a workstation environment, 4) traditional material can …

An Algorithm For Resource Allocation Requiring Low Overhead Communication, Ann Marks

Computer Science Technical Reports

A heuristic algorithm for allocating resource units to sites in a distributed system is presented. Starting with a given allocation of sites, the algorithm performs a series of optimizations involving pairs of sites in an attempt to improve the worst pair-wise imbalance present in the system; termination occurs when no further improvement is possible. After outlining the general form of the algorithm, which effectively defines an entire family of algorithms, we present theoretical results that speak to the performance of the algorithm as measured in the number of optimizations that can be done, the amount of control communication required and …

An Image Processing Software Package For The Laser Scanning Phase Modulation Microscope, William J. Murray

Computer Science Technical Reports

This thesis documents the most recent effort to develop a user-friendly image processing software package for the Laser Scanning Phase Modulation Microscope (LSPMM). The LSPMM is composed of three integrated subsystems, the Laser Scanning (LS) system, the Phase Modulation (PM) system, and Digital Image Acquisition (DIA) system. Under the control of the image processing software, the DIA system can receive and store the digital image data, display the image on a monochrome monitor, and process the image to provide the microscopist with quantitative information regarding the image. The implementation of this image processing software package required the specification of a …

View-3 And Ada: Tools For Building Systems With Many Tasks, Ann Kratzer, Mark Sherman

Dartmouth Scholarship

This paper discusses some useful features for tools that are intended to be used for developing systems with multiple tasks. We include a description of one tool that has been built, View-3. We also describe some problems that might be encountered when trying to fit this kind of tool into an APSE system.