Economies of Scale within State Prisons

This paper analyzes the cost of state prisons as a function of state prison populations across U.S. states. Historically and intuitively, a given state\u27s prison expenditures have risen as more inmates enter the prison system. Through panel regression analysis, a detailed understanding is obtained of how state prisons experience economies of scale as inmate populations rise over time. Our model consists of a single function. The equation is quadratic in nature and uses a cost function to see if there are economies of scale within the state prison systems. Our results indicate that as prison populations increase over time, the cost per-prisoner decreases at a decreasing rate. We find that state prison systems are experiencing economies of scale

The Development of a Highly Reliable Power Management and Distribution System for Civil Transport Aircraft

NASA is pursuing a program in Advanced Subsonic Transport (AST) to develop the technology for a highly reliable Fly-By-Light/Power-By-WIre aircraft. One of the primary objectives of the program is to develop the technology base for confident application of integrated PBW components and systems to transport aircraft to improve operating reliability and efficiency. Technology will be developed so that the present hydraulic and pneumatic systems of the aircraft can be systematically eliminated and replaced by electrical systems. These motor driven actuators would move the aircraft wing surfaces as well as the rudder to provide steering controls for the pilot. Existing aircraft electrical systems are not flight critical and are prone to failure due to Electromagnetic Interference (EMI) (1), ground faults and component failures. In order to successfully implement electromechanical flight control actuation, a Power Management and Distribution (PMAD) System must be designed having a reliability of 1 failure in 10(exp +9) hours, EMI hardening and a fault tolerance architecture to ensure uninterrupted power to all aircraft flight critical systems. The focus of this paper is to analyze, define, and describe technically challenging areas associated with the development of a Power By Wire Aircraft and typical requirements to be established at the box level. The authors will attempt to propose areas of investigation, citing specific military standards and requirements that need to be revised to accommodate the 'More Electric Aircraft Systems'

Estabilización de subrasantes blandas con escoria de acero en caminos vecinales, carretera ingreso Urbanización El Algarrobal, Ilo, Moquegua 2021

La presente investigación titula: Estabilización de Subrasantes Blandas con Escoria de Acero en Caminos Vecinales, Carretera Ingreso Urbanización el Algarrobal, Ilo, Moquegua 2021, tiene por objetivo estabilizar las subrasantes blandas con escoria de acero en caminos vecinales, carretera ingreso urbanización el algarrobal, Ilo, Moquegua 2021. Como metodología se aplicó el método cuantitativo, se utilizó tipo aplicada, con nivel descriptivo y diseño experimental, la técnica fue de observación directa e instrumento fueron fichas de observación, como población se utilizó la Carretera ingreso urbanización el algarrobal, en la ciudad de Ilo con una longitud de 1000 metros, la muestra estará delimitada desde el km 0+00 hasta el kilómetro 0+600, con muestreo probabilístico y sub tipo intencional. Los resultados fueron: que en el presente proyecto de investigación el suelo presenta una mejor estabilización agregando 12% de escoria de acero teniendo como resultados una máxima densidad seca que varía desde 2.031 gr/cm3, 2.059 gr/cm3 y 2.146 gr/cm3, un CBR (Californian Bearing Ratio) promedio a una compactación de 95% con escoria de acero que varía desde 13.417%, 19.617% y 28.743%, un módulo de resiliencia promedio con la adición de escoria de acero varia desde 13461.190 psi, 17166.076 psi y 21920.713 psi y un índice de plasticidad de 0%, 0% y 0% para adiciones de escoria de acero de 3%, 6%, 12% respectivamente

Maximum likelihood thresholds via graph rigidity

DIB was partially supported by a Mathematical Sciences Postdoctoral Research Fellowship from the US NSF Grant DMS-1802902. SD was partially supported by the Austrian Science Fund (FWF): P31888. AN was partially supported by the Heilbronn Institute for Mathematical Research. SJG was partially supported by US NSF Grant DMS-1564473. MS was partially supported by US NSF Grant DMS-1564480 and US NSF Grant DMS-1563234.The maximum likelihood threshold (MLT) of a graph G is the minimum number of samples to almost surely guarantee existence of the maximum likelihood estimate in the corresponding Gaussian graphical model. We give a new characterization of the MLT in terms of rigidity-theoretic properties of G and use this characterization to give new combinatorial lower bounds on the MLT of any graph. We use the new lower bounds to give high-probability guarantees on the maximum likelihood thresholds of sparse Erd{ö}s-Rényi random graphs in terms of their average density. These examples show that the new lower bounds are within a polylog factor of tight, where, on the same graph families, all known lower bounds are trivial. Based on computational experiments made possible by our methods, we conjecture that the MLT of an Erd{ö}s-Rényi random graph is equal to its generic completion rank with high probability. Using structural results on rigid graphs in low dimension, we can prove the conjecture for graphs with MLT at most 4 and describe the threshold probability for the MLT to switch from 3 to 4. We also give a geometric characterization of the MLT of a graph in terms of a new "lifting" problem for frameworks that is interesting in its own right. The lifting perspective yields a new connection between the weak MLT (where the maximum likelihood estimate exists only with positive probability) and the classical Hadwiger-Nelson problem.Peer reviewe

The density and porosity of lunar rocks

Accurate lunar rock densities are necessary for constructing gravity models of the Moon\u27s crust and lithosphere. Most Apollo-era density measurements have errors of 2-5% or more and few include porosity measurements. We report new density and porosity measurements using the bead method and helium pycnometry for 6 Apollo samples and 7 lunar meteorites, with typical grain density uncertainties of 10-30 kg m(-3) (0.3-0.9%) and porosity uncertainties of 1-3%. Comparison between igneous grain densities and normative mineral densities show that these uncertainties are realistic and that the helium fully penetrates the pore space. Basalt grain densities are a strong function of composition, varying over at least 3270 kg m(-3) (high aluminum basalt) to 3460 kg m(-3) (high titanium basalt). Feldspathic highland crust has a bulk density of 22002600 kg m(-3) and porosity of 10-20%. Impact basin ejecta has a bulk density of 2350-2600 kg m(-3) and porosity of similar to 20%

Enriched Shergottite NWA 5298 As An Evolved Parent Melt: Trace Element Inventory

Martian meteorite Northwest Africa 5298 is a basaltic shergottite that was found near Bir Gandouz (Morocco). Its martian origin was confirmed by oxygen isotopes [1], as well as Mn/Fe ratios in the pyroxenes and K/anorthite ratios in the plagioclases [2]. Here we present a petrographic and geochemical study of NWA 5298. Comparison of mineralogical and geochemical characteristics of this meteorite with other Martian rocks shows that NWA 5298 is not likely paired with any other known shergottites, but it has similarities to another basaltic shergottite Dhofar 378