NECA Ghana Project

Cal Poly’s motto is, “Learn by Doing and for Cal Poly’s NECA Chapter, this isn’t simply a motto, but a directive for proactive change. For my senior project I will be leading the Cal Poly NECA chapter in the design, pre- fabrication and construction of a 5-7kw solar array, community center, ice production room and technology room in the remote fishing village of Agbokpa, Ghana. The solar array will power multiple industrial DC freezers, high efficiency LED lighting and charging stations while additionally powering water filtration and irrigation systems. Like many other fishing villages around the world, Agbokpa has no means of ice production or access to clean water due to their disconnection from a power grid, contributing substantially to their impoverishment

Linear algebraic techniques for spanning tree enumeration

Kirchhoff's Matrix-Tree Theorem asserts that the number of spanning trees in a finite graph can be computed from the determinant of any of its reduced Laplacian matrices. In many cases, even for well-studied families of graphs, this can be computationally or algebraically taxing. We show how two well-known results from linear algebra, the Matrix Determinant Lemma and the Schur complement, can be used to elegantly count the spanning trees in several significant families of graphs.Comment: This paper presents unweighted versions of the results in arXiv:1903.03575 with more concrete and concise proofs. It is intended for a broad audience and has extra emphasis on exposition. It will appear in the American Mathematical Monthl

Kalman Filters for Time Delay of Arrival-based Source Localization

In this work, we propose an algorithm for acoustic source localization based on time delay of arrival (TDOA) estimation. In earlier work by other authors, an initial closed-form approximation was first used to estimate the true position of the speaker followed by a Kalman filtering stage to smooth the time series of estimates. In the proposed algorithm, this closed-form approximation is eliminated by employing a Kalman filter to directly update the speaker\u27s position estimate based on the observed TDOAs. In particular, the TDOAs comprise the observation associated with an extended Kalman filter whose state corresponds to the speaker\u27s position. We tested our algorithm on a data set consisting of seminars held by actual speakers. Our experiments revealed that the proposed algorithm provides source localization accuracy superior to the standard spherical and linear intersection techniques. Moreover, the proposed algorithm, although relying on an iterative optimization scheme, proved efficient enough for real-time operation

Phonological characteristics of the lexicon at 2;0 years predict language outcomes at 3;6 years

Poster session 3 - Early speech production: no. 7Toddlers’ first words are of higher mean phonological neighborhood density (ND) than words learned later. The words of children with delayed lexical development are of significantly higher mean ND than those of typically developing children. A relationship between a higher mean ND value at 2;0 years and expressive language skills at 3;6 years may indicate that early word processing difficulties inhibit ongoing development ...postprin