Deployable antenna phase A study

Applications for large deployable antennas were re-examined, flight demonstration objectives were defined, the flight article (antenna) was preliminarily designed, and the flight program and ground development program, including the support equipment, were defined for a proposed space transportation system flight experiment to demonstrate a large (50 to 200 meter) deployable antenna system. Tasks described include: (1) performance requirements analysis; (2) system design and definition; (3) orbital operations analysis; and (4) programmatic analysis

Analysis of Gender and Youth Employment in Rwanda

This study focuses on labor outcomes of women and youth?the former have moved into low-quality employment, while the latter have high rates of underemployment. Labor market outcomes are examined through geographic analysis and a study of factors affecting employment at the individual level. The analysis is based on cross-sectional data collected by the National Institute of Statistics of Rwanda (NISR). The study uses the two most recent waves of the nationally representative household surveys for 2005/06 and 2010/11. The other source was the 2010 Rwanda Demographic and Health Survey. The methods used to meet the study objectives were a literature review of previous work on the Rwandan labor market, participation profiling via a descriptive analysis, and econometric analysis of determinants of employment outcomes

Dictators, Repression and the Median Citizen: An “Eliminations Model” of Stalin’s Terror (Data from the NKVD Archives)

This paper sheds light on dictatorial behavior as exemplified by the mass terror campaigns of Stalin. Dictatorships – unlike democracies where politicians choose platforms in view of voter preferences – may attempt to trim their constituency and thus ensure regime survival via the large scale elimination of citizens. We formalize this idea in a simple model and use it to examine Stalin’s three large scale terror campaigns with data from the NKVD state archives that are accessible after more than 60 years of secrecy. Our model traces the stylized facts of Stalin’s terror and identifies parameters such as the ability to correctly identify regime enemies, the actual or perceived number of enemies in the population, and how secure the dictators power base is, as crucial for the patterns and scale of repression.Dictatorial systems, Stalinism, Soviet State and Party archives, NKVD, OPGU,Repression

Optimal allocation of defibrillator drones in mountainous regions

Responding to emergencies in Alpine terrain is quite challenging as air ambulances and mountain rescue services are often confronted with logistics challenges and adverse weather conditions that extend the response times required to provide life-saving support. Among other medical emergencies, sudden cardiac arrest (SCA) is the most time-sensitive event that requires the quick provision of medical treatment including cardiopulmonary resuscitation and electric shocks by automated external defibrillators (AED). An emerging technology called unmanned aerial vehicles (or drones) is regarded to support mountain rescuers in overcoming the time criticality of these emergencies by reducing the time span between SCA and early defibrillation. A drone that is equipped with a portable AED can fly from a base station to the patient's site where a bystander receives it and starts treatment. This paper considers such a response system and proposes an integer linear program to determine the optimal allocation of drone base stations in a given geographical region. In detail, the developed model follows the objectives to minimize the number of used drones and to minimize the average travel times of defibrillator drones responding to SCA patients. In an example of application, under consideration of historical helicopter response times, the authors test the developed model and demonstrate the capability of drones to speed up the delivery of AEDs to SCA patients. Results indicate that time spans between SCA and early defibrillation can be reduced by the optimal allocation of drone base stations in a given geographical region, thus increasing the survival rate of SCA patients

Collaborative research on V/STOL control system/cockpit display tradeoffs under the NASA/MOD joint aeronautical program

Summarized here are activities that have taken place from 1979 to the present in a collaborative program between NASA Ames Research Center and the Royal Aerospace Establishment (now Defence Research Agency), Bedford on flight control system and cockpit display tradeoffs for low-speed and hover operations of future V/STOL aircraft. This program was created as Task 8A of the Joint Aeronautical Program between NASA in the United States and the Ministry of Defence (Procurement Executive) in the United Kingdom. The program was initiated based on a recognition by both parties of the strengths of the efforts of their counterparts and a desire to participate jointly in future simulation and flight experiments. In the ensuing years, teams of NASA and RAE engineers and pilots have participated in each other's simulation experiments to evaluate control and display concepts and define design requirements for research aircraft. Both organizations possess Harrier airframes that have undergone extensive modification to provide in-flight research capabilities in the subject areas. Both NASA and RAE have profited by exchanges of control/display concepts, design criteria, fabrication techniques, software development and validation, installation details, and ground and flight clearance techniques for their respective aircraft. This collaboration has permitted the two organizations to achieve jointly substantially more during the period than if they had worked independently. The two organizations are now entering the phase of flight research for the collaborative program as currently defined

Risk analysis methodology survey

NASA regulations require that formal risk analysis be performed on a program at each of several milestones as it moves toward full-scale development. Program risk analysis is discussed as a systems analysis approach, an iterative process (identification, assessment, management), and a collection of techniques. These techniques, which range from simple to complex network-based simulation were surveyed. A Program Risk Analysis Handbook was prepared in order to provide both analyst and manager with a guide for selection of the most appropriate technique

Active repositioning of storage units in Robotic Mobile Fulfillment Systems

In our work we focus on Robotic Mobile Fulfillment Systems in e-commerce distribution centers. These systems were designed to increase pick rates by employing mobile robots bringing movable storage units (so-called pods) to pick and replenishment stations as needed, and back to the storage area afterwards. One advantage of this approach is that repositioning of inventory can be done continuously, even during pick and replenishment operations. This is primarily accomplished by bringing a pod to a storage location different than the one it was fetched from, a process we call passive pod repositioning. Additionally, this can be done by explicitly bringing a pod from one storage location to another, a process we call active pod repositioning. In this work we introduce first mechanisms for the latter technique and conduct a simulation-based experiment to give first insights of their effect