Marshall Space Flight Center Research and Technology Report 2015

The investments in technology development we made in 2015 not only support the Agency's current missions, but they will also enable new missions. Some of these projects will allow us to develop an in-space architecture for human space exploration; Marshall employees are developing and testing cutting-edge propulsion solutions that will propel humans in-space and land them on Mars. Others are working on technologies that could support a deep space habitat, which will be critical to enable humans to live and work in deep space and on other worlds. Still others are maturing technologies that will help new scientific instruments study the outer edge of the universe-instruments that will provide valuable information as we seek to explore the outer planets and search for life

Dark Matter Searches with the LUX and LZ Experiments

The fundamental nature of our universe is still mostly unknown. Dark matter, known to make up 84% of the mass in the universe, is widely recognised as one of the biggest mysteries in modern science. A promising candidate is the Weakly Interacting Massive Particle, or WIMP; these enigmatic particles have so far evaded detection by anything other than their gravitational influence, but they are an elegant solution that may still be hiding in unexplored phase space. WIMPs may be detected through elastic nuclear scattering in low-background experiments located in deep underground laboratories. The LUX dark matter experiment operates a time projection chamber with a xenon target, and has been world-leading for 3 years. LUX pioneered calibration techniques that have allowed great improvements in the sensitivity to WIMPs, developed novel signal identification algorithms towards rare-event selection, and demonstrated low energy nuclear recoil efficiency for WIMPs to unprecedented levels for noble gas targets. LUX has set the most-stringent constraints on WIMPs to-date with a minimum sensitivity of 2.2E10-46 cm2 at a WIMP mass of 50 GeV/c2. The LUX experiment has been completed, but the search will be taken up by its successor LUXZEPLIN (LZ), now under construction. Building on the technologies and techniques developed for LUX, LZ will probe theoretically well-motivated regions of unexplored electroweak parameter space to reach a sensitivity at 2E10-48 at 50 GeV/c2, 100 times greater than LUX. Detailed Monte Carlo simulations have been conducted for LZ to inform and finalise design, and develop the background model, against which any potential signal will be evaluated for a first definitive discovery

AIRO 2016. 46th Annual Conference of the Italian Operational Research Society. Emerging Advances in Logistics Systems Trieste, September 6-9, 2016 - Abstracts Book

The AIRO 2016 book of abstract collects the contributions from the conference participants. The AIRO 2016 Conference is a special occasion for the Italian Operations Research community, as AIRO annual conferences turn 46th edition in 2016. To reflect this special occasion, the Programme and Organizing Committee, chaired by Walter Ukovich, prepared a high quality Scientific Programme including the first initiative of AIRO Young, the new AIRO poster section that aims to promote the work of students, PhD students, and Postdocs with an interest in Operations Research. The Scientific Programme of the Conference offers a broad spectrum of contributions covering the variety of OR topics and research areas with an emphasis on “Emerging Advances in Logistics Systems”. The event aims at stimulating integration of existing methods and systems, fostering communication amongst different research groups, and laying the foundations for OR integrated research projects in the next decade. Distinct thematic sections follow the AIRO 2016 days starting by initial presentation of the objectives and features of the Conference. In addition three invited internationally known speakers will present Plenary Lectures, by Gianni Di Pillo, Frédéric Semet e Stefan Nickel, gathering AIRO 2016 participants together to offer key presentations on the latest advances and developments in OR’s research

A theoretical and methodological framework for machine learning in survival analysis: Enabling transparent and accessible predictive modelling on right-censored time-to-event data

Survival analysis is an important field of Statistics concerned with mak- ing time-to-event predictions with ‘censored’ data. Machine learning, specifically supervised learning, is the field of Statistics concerned with using state-of-the-art algorithms in order to make predictions on unseen data. This thesis looks at unifying these two fields as current research into the two is still disjoint, with ‘classical survival’ on one side and su- pervised learning (primarily classification and regression) on the other. This PhD aims to improve the quality of machine learning research in survival analysis by focusing on transparency, accessibility, and predic- tive performance in model building and evaluation. This is achieved by examining historic and current proposals and implementations for models and measures (both classical and machine learning) in survival analysis and making novel contributions. In particular this includes: i) a survey of survival models including a crit- ical and technical survey of almost all supervised learning model classes currently utilised in survival, as well as novel adaptations; ii) a survey of evaluation measures for survival models, including key definitions, proofs and theorems for survival scoring rules that had previously been missing from the literature; iii) introduction and formalisation of composition and reduction in survival analysis, with a view on increasing transparency of modelling strategies and improving predictive performance; iv) imple- mentation of several R software packages, in particular mlr3proba for machine learning in survival analysis; and v) the first large-scale bench- mark experiment on right-censored time-to-event data with 24 survival models and 66 datasets. Survival analysis has many important applications in medical statistics, engineering and finance, and as such requires the same level of rigour as other machine learning fields such as regression and classification; this thesis aims to make this clear by describing a framework from prediction and evaluation to implementation

Measurement of the lifetimes of B meson mass eigenstates

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2004.Includes bibliographical references (p. 201-209).In this dissertation, we present the results of the average lifetime measurements in ..., ..., and ... decays, as well as the results of a time-dependent angular analysis of ... and ... decays. The time-dependent angular analysis of ... allows the extraction of separate lifetimes for the mass eigenstates, ... and ..., in the ... system. The two lifetimes are combined to extract the width difference, ..., between the two eigenstates. This quantity is extremely useful for over-constraining the Unitarity Triangle and thereby inferring if CP violation in the quark sector is entirely explained within the Standard Model. From ... of data collected by CDF up to February 13, 2004, we obtain a wealth of results, most importantly: ... Several of the results obtained here are currently the best of their kind, and in some cases they are unique measurements. We devote special attention to these, in particular ...by Konstantin Anikeev.Ph.D

Studies in geophysics: The Earth's electrical environment

The Earth is electrified. Between the surface and the outer reaches of the atmosphere, there is a global circuit that is maintained by worldwide thunderstorm activity and by upper atmospheric dynamo processes. The highest voltages approach a billion volts and are generated within thunderclouds, where lightning is a visual display of the cloud's electrical nature. The largest currents in the circuit, approaching a million amperes, are associated with the aurora. Because there have been significant advances in understanding many of the component parts of the global electric circuit (lightning, cloud electrification, electrical processes in specific atmospheric regions, and telluric currents), a principal research challenge is to understand how these components interact to shape the global circuit. Increased basic understanding in this field has many potential practical applications, including lightning protection, the design of advanced aircraft and spacecraft, and improvements in weather prediction

Aeronautical Engineering: A continuing bibliography with indexes

This bibliography lists 512 reports, articles and other documents introduced into the NASA scientific and technical information system in April 1982

Divergence in Architectural Research

ConCave Ph.D. Symposium 2020: Divergence in Architectural Research, March 5-6, 2020, Georgia Institute of Technology, Atlanta, GA.The essays in this volume have come together under the theme “Divergence in Architectural Research” and present a snapshot of Ph.D. research being conducted in over thirty architectural research institutions, representing fourteen countries around the world. These essays also provide a window into the presentations and discussions that took place March 5-6, 2020, during the ConCave Ph.D. Symposium “Divergence in Architectural Research,” under the auspices of the School of Architecture, Georgia Institute of Technology, in Atlanta, Georgia. On a preliminary reading, the essays respond to the call of divergence by doing just that; they present the great diversity of research topics, methodologies, and practices currently found under the umbrella of “architectural research.” They inform inquiry within architectural programs and across disciplinary concentrations, and also point to the ways that the academy, research methodologies, and the design profession are evolving and encroaching upon one another, with the unspoken hope of encouraging new relationships, reconfiguring previous assumptions about the discipline, and interweaving research and practice