Topology Optimization for Artificial Neural Networks

This thesis examines the feasibility of implementing two simple optimization methods, namely the Weights Power method (Hagiwara, 1994) and the Tabu Search method (Gupta & Raza, 2020), within an existing framework. The study centers around the generation of artificial neural networks using these methods, assessing their performance in terms of both accuracy and the capacity to reduce components within the Artificial Neural Network’s (ANN) topology. The evaluation is conducted on three classification datasets: Air Quality (Shahane, 2021), Diabetes (Soni, 2021), and MNIST (Deng, 2012). The main performance metric used is accuracy, which measures the network\u27s predictive capability for the classification datasets. The evaluation also considers the reduction of network components achieved by the methods as an indicator of topology optimization. Python, along with the Scikit-learn framework, is employed to implement the two methods, while the evaluation is conducted in the cloud-based environment of Kaggle Notebooks. The evaluation results are collected and analyzed using the Pandas data analysis framework, with Microsoft Excel used for further analysis and data inspection. The Weights Power method demonstrates superior performance on the Air Quality and MNIST datasets, whereas the Tabu Search method performs better on the Diabetes dataset. However, the Weights Power method encounters issues with local minima, leading to one of its stop conditions being triggered. On the other hand, the Tabu Search method faces challenges with the MNIST dataset due to its predetermined limits and restricted scope of changes it can apply to the neural network. The Weights Power method seems to have reached its optimal performance level within the current implementation and evaluation criteria, implying limited potential for future research avenues. In contrast, to enhance the dynamic nature of the Tabu Search method, further investigation is recommended. This could entail modifying the method\u27s capability to adapt its stop conditions during runtime and incorporating a mechanism to scale the magnitude of changes made during the optimization process. By enabling the method to prioritize larger changes earlier in the process and gradually introducing smaller changes towards the conclusion, its effectiveness could be enhanced

Challenging Payday Lenders by Opening up the Market for Small-Dollar Loans

“Why hasn’t someone else stepped in to lend at lower interest rates?” is the question frequently asked in discussions of payday loans. The average payday loan carries an Annual Percentage Rate (APR) of over 300%. Given the strength of th e payday lenders lobby at the federal and state level, one way to help low- and moderate-income households escape the financial harms of pa yday loans is to encourage other lenders to enter the small-dollar loan market and offer more affordable products. Over the past ten years, an array of affordable small-dollar loan programs offered by banks, credit unions, non-profit organizations, and for-profit fintech compan ies have entered the market to provide borrowers with alternatives to payday loans. These lenders are offering small-dollar loans at rates and on terms that are more manageable for low- and moderate-income consumers than payday loans, while maintaining the features of payday loans that consumers like—namely quick and easy access to credit. This paper w ill desc ribe these affordable small-dollar loan programs and explain what is needed from regulators, financial institutions and foundations, and consumer advocates for the programs to serve more borrowers and take over more of the market space curren tly occupied by payday lenders. Banks, with support from t he ir regulators, can offer affordable small-dollar loans to their customers and should continue to provide low-in terest loan capital to non-profit small-dollar lenders. Credit unions can continue to offer small-dollar loan programs like the Payday Alte rnative Loan product and the Employer Sponsored Small-Dollar Loan product and should be encouraged to do so by their regulators. Non-profit organizations can continue to offer affordable loans in partnership with employers or other lenders and should be provided with grants and low-interest loan capital and pro-bono support from la wyers and marketing companies. For-profit, fintech lenders can continue to enter this space and should be supported by consumer advocates and regulators as long as their products meet certain guidelines: compliance with all federal and state laws, affordable payments, and features such as credit bureau reporting, transparent fees, and flexible repayment terms. Finally, recent efforts in Congress to encourage the U. S. Postal Service to offer affordable small-dollar loans should also be supported. The short-term small-dollar credit needs of low- and moderateincome households should not be met primarily by payday lenders whose high fees and short repayment terms too often trap borrowers in a cycle of debt. Low-and moderate-income consumers deserve better options. With support, the affordable small-dollar loan programs described in this paper can be expanded to make the market for smalldollar credit more competitive, helping borrowers across the country

Increasing design communication using virtual reality

Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1999.Includes bibliographical references (leaf 55).by Justin W. Mills.M.Eng

A Table of Third and Fourth Order Feynman Diagrams of the Interacting Fermion Green's Function

The Feynman diagrams of the Green's function expansion of fermions interacting with a non-relativistic 2-body interaction are displayed in first, second and third order of the interaction as 2, 10 and 74 diagrams, respectively. A name convention for the diagrams is proposed and then used to tabulate the 706 diagrams of fourth order. The Hartree-Fock approximation summons up 2, 8, 40 and 224 of them, respectively.Comment: 12 pages, 13 figures, 16 tables. Index typo in Sect III corrected. More lines in Table XV. Three more references. Expanded Summar

Design and Analysis of a Dynamically Configured Log-based Distributed Security Event Detection Methodology

Military and defense organizations rely upon the security of data stored in, and communicated through, their cyber infrastructure to fulfill their mission objectives. It is essential to identify threats to the cyber infrastructure in a timely manner, so that mission risks can be recognized and mitigated. Centralized event logging and correlation is a proven method for identifying threats to cyber resources. However, centralized event logging is inflexible and does not scale well, because it consumes excessive network bandwidth and imposes significant storage and processing requirements on the central event log server. In this paper, we present a flexible, distributed event correlation system designed to overcome these limitations by distributing the event correlation workload across the network of event-producing systems. To demonstrate the utility of the methodology, we model and simulate centralized, decentralized, and hybrid log analysis environments over three accountability levels and compare their performance in terms of detection capability, network bandwidth utilization, database query efficiency, and configurability. The results show that when compared to centralized event correlation, dynamically configured distributed event correlation provides increased flexibility, a significant reduction in network traffic in low and medium accountability environments, and a decrease in database query execution time in the high-accountability case

A doubly-refined enumeration of alternating sign matrices and descending plane partitions

It was shown recently by the authors that, for any n, there is equality between the distributions of certain triplets of statistics on nxn alternating sign matrices (ASMs) and descending plane partitions (DPPs) with each part at most n. The statistics for an ASM A are the number of generalized inversions in A, the number of -1's in A and the number of 0's to the left of the 1 in the first row of A, and the respective statistics for a DPP D are the number of nonspecial parts in D, the number of special parts in D and the number of n's in D. Here, the result is generalized to include a fourth statistic for each type of object, where this is the number of 0's to the right of the 1 in the last row of an ASM, and the number of (n-1)'s plus the number of rows of length n-1 in a DPP. This generalization is proved using the known equality of the three-statistic generating functions, together with relations which express each four-statistic generating function in terms of its three-statistic counterpart. These relations are obtained by applying the Desnanot-Jacobi identity to determinantal expressions for the generating functions, where the determinants arise from standard methods involving the six-vertex model with domain-wall boundary conditions for ASMs, and nonintersecting lattice paths for DPPs.Comment: 28 pages; v2: published versio

Scientific Integrity: Producing, Incorporating, and Advocating for Science in the Age of Alternative Facts

Technical information – along with politics, economics, public opinion, societal values, and legal considerations – is one input into wildlife management decisions.  As information consumers, decision-makers require objectivity of those who produce such information, and should have an understanding of the inference scope and strength (and uncertainty) associated with technical information.  Information producers must earn, demonstrate, and protect that reputation of objectivity.  Both producers and consumers must both foster and guard a culture of integrity, such that the processes of producing and applying information are transparent and can withstand intense scrutiny.  Today, rather suddenly, there is national discourse on these subjects of transparency, professional integrity, and rigorous questioning and defense of scientific information.  The discussion of the role of science and scientists in informing public policy has assumed a prominent position in traditional and social media.  This panel, consisting of representatives from federal, state, tribal, and non-governmental organizations will engage in this discussion with the audience

Enantioselective Synthesis of Enantioisotopomers with Quantitative Chiral Analysis by Chiral Tag Rotational Spectroscopy

Fundamental to the synthesis of enantioenriched chiral molecules is the ability to assign absolute configuration at each stereogenic center, and to determine the enantiomeric excess for each compound. While determination of enantiomeric excess and absolute configuration is often considered routine in many facets of asymmetric synthesis, the same determinations for enantioisotopomers remains a formidable challenge. Here, we report the first highly enantioselective metal-catalyzed synthesis of enantioisotopomers that are chiral by virtue of deuterium substitution along with the first general spectroscopic technique for assignment of the absolute configuration and quantitative determination of the enantiomeric excess of isotopically chiral molecules. Chiral tag rotational spectroscopy uses noncovalent chiral derivatization, which eliminates the possibility of racemization during derivatization, to perform the chiral analysis without the need of reference samples oft he enantioisotopomer

Multiply-refined enumeration of alternating sign matrices

Four natural boundary statistics and two natural bulk statistics are considered for alternating sign matrices (ASMs). Specifically, these statistics are the positions of the 1's in the first and last rows and columns of an ASM, and the numbers of generalized inversions and -1's in an ASM. Previously-known and related results for the exact enumeration of ASMs with prescribed values of some of these statistics are discussed in detail. A quadratic relation which recursively determines the generating function associated with all six statistics is then obtained. This relation also leads to various new identities satisfied by generating functions associated with fewer than six of the statistics. The derivation of the relation involves combining the Desnanot-Jacobi determinant identity with the Izergin-Korepin formula for the partition function of the six-vertex model with domain-wall boundary conditions.Comment: 62 pages; v3 slightly updated relative to published versio

Comparative effectiveness of monotherapies and combination therapies for patients with hypertension: protocol for a systematic review with network meta-analyses

BACKGROUND: Hypertension has been cited as the most common attributable risk factor for death worldwide, and in Canada more than one of every five adults had this diagnosis in 2007. In addition to different lifestyle modifications, such as diet and exercise, there exist many pharmaco-therapies from different drug classes which can be used to lower blood pressure, thereby reducing the risk of serious clinical outcomes. In moderate and severe cases, more than one agent may be used. The optimal mono- and combination therapies for mild hypertension and moderate/severe hypertension are unclear, and clinical guidelines provide different recommendations for first line therapy. The objective of this review is to explore the relative benefits and safety of different pharmacotherapies for management of non-diabetic patients with hypertension, whether of a mild or moderate to severe nature. METHODS/DESIGN: Searches involving MEDLINE and the Cochrane Database of Systematic Reviews will be used to identify related systematic reviews and relevant randomized trials. The outcomes of interest include myocardial infarction, stroke, incident diabetes, heart failure, overall and cardiovascular related death, and important side effects (cancers, depression, syncopal episodes/falls and sexual dysfunction). Randomized controlled trials will be sought. Two reviewers will independently screen relevant reviews, titles and abstracts resulting from the literature search, and also potentially relevant full-text articles in duplicate. Data will be abstracted and quality will be appraised by two team members independently. Conflicts at all levels of screening and abstraction will be resolved through team discussion. Random effect pairwise meta-analyses and network meta-analyses will be conducted where deemed appropriate. Analyses will be geared toward studying treatment of mild hypertension and moderate/severe hypertension separately. DISCUSSION: Our systematic review results will assess the extent of currently available evidence for single agent and multi-agent pharmacotherapies in patients with mild, moderate and severe hypertension, and will provide a rigorous and updated synthesis of a range of important clinical outcomes for clinicians, decision makers and patients. TRIAL REGISTRATION: PROSPERO Registration Number: CRD4201300445