An Analysis of Iterative Algorithms for Image Reconstruction from Satellite Earth Remote Sensing Data

This paper discusses algorithms for creating enhanced-resolution images from satellite earth remote sensing data. The well-known ART and MART algorithms are discussed, as well as a new class of algorithms-column-normalized algorithms. The SART algorithm is studied as an example of a column-normalized algorithm and is compared structurally to the SIR algorithm to help explain SIR\u27s success at remote sensing image reconstruction. Several reconstruction algorithms are then compared using both simulated and real satellite radiometer data sets

Cluster Typologies and Firm Survival: Complementary and Substitutive Effects

Agglomerations, or clusters, are typically defined as the idea that firms can benefit from shared locations through mutual knowledge, labor pools, and suppliers, and have long been a subject of scholarly interest. However, research in geographic economics has identified a broad array of agglomeration externalities beyond such supply-side clusters, which problematizes the use of the term cluster to refer to any geographic grouping of firms. Clusters can be groups of firms from the same country ( country-of-origin clusters), demand side (clustering to lower search costs for customers), Jacobsian clusters (tight groups of diverse firms), internal (groupings of firms from the same parent company), or urban (focused in areas of high population density). Since the nature of inter-firm interactions should differ in each type of agglomeration, our study contributes to the agglomeration literature by identifying complementary and substitutive relationships between agglomeration typologies. Specifically, we extend prior work which has examined the mutual effects of Jacobsian and Marshallian externalities by attempting to answer our research question, i.e., what combination of agglomeration externalities consistently leads to firm survival? Using establishment-level data from the software and clothing industries in the state of Texas, we identify multiple combinations of cluster types (and their absence) which lead to firm survival on a consistent basis. The results find several combinations of causal mechanisms that lead to the equifinal outcome of firm survival. Our configurations exceed levels supported by prior literature with PRI scores over .7 and coverage scores between .05 and .109.https://digitalcommons.odu.edu/gradposters2023_business/1001/thumbnail.jp

Slack, Location, Diversification, or R&D Intensity? How the Most (and Least) Innovative Firms Deploy Resources

Firms frequently innovate by recombining knowledge components. Through bringing together diverse scientific or technological concepts, firms can reassemble these extant knowledge components into novel and useful innovations. At the same time, many of the mechanisms firms use to recombine knowledge components carry substantial agency costs. When firms conduct research and development, diversify, hold slack resources, or locate near close competitors, they become vulnerable to misappropriation of investor resources due to opportunistic actions by agents. Using patent citation data from semiconductor firms, we study how firms, which consistently produce high-quality innovations, balance the need for knowledge recombination with the need to protect investors from opportunism. Our results indicate that, consistent with an agency lens, innovative firms operate under a significant debt load. Consistent with the knowledge recombination perspective, however, innovative firms typically engage in multiple activities that lead to innovation via knowledge recombination.https://digitalcommons.odu.edu/gradposters2023_business/1002/thumbnail.jp

Costs and cost-effectiveness of delivering intermittent preventive treatment through schools in western Kenya

BACKGROUND: Awareness of the potential impact of malaria among school-age children has stimulated investigation into malaria interventions that can be delivered through schools. However, little evidence is available on the costs and cost-effectiveness of intervention options. This paper evaluates the costs and cost-effectiveness of intermittent preventive treatment (IPT) as delivered by teachers in schools in western Kenya. METHODS: Information on actual drug and non-drug associated costs were collected from expenditure and salary records, government budgets and interviews with key district and national officials. Effectiveness data were derived from a cluster-randomised-controlled trial of IPT where a single dose of sulphadoxine-pyrimethamine and three daily doses of amodiaquine were provided three times in year (once termly). Both financial and economic costs were estimated from a provider perspective, and effectiveness was estimated in terms of anaemia cases averted. A sensitivity analysis was conducted to assess the impact of key assumptions on estimated cost-effectiveness. RESULTS: The delivery of IPT by teachers was estimated to cost US$1.88 per child treated per year, with drug and teacher training costs constituting the largest cost components. Set-up costs accounted for 13.2$ 0.25 per child) whilst recurrent costs accounted for 86.8% (US$1.63 per child per year). The estimated cost per anaemia case averted was US$ 29.84 and the cost per case of Plasmodium falciparum parasitaemia averted was US$5.36, respectively. The cost per case of anaemia averted ranged between US$ 24.60 and 40.32 when the prices of antimalarial drugs and delivery costs were varied. Cost-effectiveness was most influenced by effectiveness of IPT and the background prevalence of anaemia. In settings where 30% and 50% of schoolchildren were anaemic, cost-effectiveness ratios were US$ 12.53 and 7.52, respectively. CONCLUSION: This study provides the first evidence that IPT administered by teachers is a cost-effective school-based malaria intervention and merits investigation in other settings

The PyCBC search for gravitational waves from compact binary coalescence

We describe the PyCBC search for gravitational waves from compact-object binary coalescences in advanced gravitational-wave detector data. The search was used in the first Advanced LIGO observing run and unambiguously identified two black hole binary mergers, GW150914 and GW151226. At its core, the PyCBC search performs a matched-filter search for binary merger signals using a bank of gravitational-wave template waveforms. We provide a complete description of the search pipeline including the steps used to mitigate the effects of noise transients in the data, identify candidate events and measure their statistical significance. The analysis is able to measure false-alarm rates as low as one per million years, required for confident detection of signals. Using data from initial LIGO's sixth science run, we show that the new analysis reduces the background noise in the search, giving a 30% increase in sensitive volume for binary neutron star systems over previous searches.Comment: 29 pages, 7 figures, accepted by Classical and Quantum Gravit

Open source drug discovery - A limited tutorial

Open science is a new concept for the practice of experimental laboratory-based research, such as drug discovery. The authors have recently gained experience in how to run such projects and here describe some straightforward steps others may wish to take towards more openness in their own research programmes. Existing and inexpensive online tools can solve many challenges, while some psychological barriers to the free sharing of all data and ideas are more substantia

Is metal theft committed by organized crime groups, and why does it matter?

Using the example of metal theft in the United Kingdom, this study used mixed methods to evaluate the accuracy of police estimates of the involvement of organised crime groups (OCGs) in crime. Police estimate that 20-30% of metal theft is committed by OCGs, but this study found that only 0.5% of metal thieves had previous convictions for offences related to OCGs, that only 1.3% were linked to OCGs by intelligence information, that metal thieves typically offended close to their homes and that almost no metal thefts involved sophisticated offence methods. It appears that police may over-estimate the involvement of OCGs in some types of crime. The reasons for and consequences of this over-estimation are discussed

Preferred reporting items for journal and conference abstracts of systematic reviews and meta-analyses of diagnostic test accuracy studies (PRISMA-DTA for Abstracts):checklist, explanation, and elaboration

For many users of the biomedical literature, abstracts may be the only source of information about a study. Hence, abstracts should allow readers to evaluate the objectives, key design features, and main results of the study. Several evaluations have shown deficiencies in the reporting of journal and conference abstracts across study designs and research fields, including systematic reviews of diagnostic test accuracy studies. Incomplete reporting compromises the value of research to key stakeholders. The authors of this article have developed a 12 item checklist of preferred reporting items for journal and conference abstracts of systematic reviews and meta-analyses of diagnostic test accuracy studies (PRISMA-DTA for Abstracts). This article presents the checklist, examples of complete reporting, and explanations for each item of PRISMA-DTA for Abstracts

Thermochemical Investigations of Solute Transfer into Ionic Solvents: Updated Abraham Model Equation Coefficients for Solute Activity Coefficient and Partition Coefficient Predictions

Article on thermochemical investigations of solute transfer into ionic liquid solvents and updated Abraham model equation coefficients for solute activity coefficient and partition coefficient predictions