Technology for the Future: In-Space Technology Experiments Program, part 2

The purpose of the Office of Aeronautics and Space Technology (OAST) In-Space Technology Experiments Program In-STEP 1988 Workshop was to identify and prioritize technologies that are critical for future national space programs and require validation in the space environment, and review current NASA (In-Reach) and industry/ university (Out-Reach) experiments. A prioritized list of the critical technology needs was developed for the following eight disciplines: structures; environmental effects; power systems and thermal management; fluid management and propulsion systems; automation and robotics; sensors and information systems; in-space systems; and humans in space. This is part two of two parts and contains the critical technology presentations for the eight theme elements and a summary listing of critical space technology needs for each theme

A Study of Defense Logistics Agency Inventory Classifications: Application of Inventory Control Methods to Reduce Total Variable Cost and Stockage Levels

This thesis analyzes the financial impact of applying a single inventory requirements model to three separate classes of inventory at the Defense Logistics Agency\u27s (DLA) Defense Supply Center-Columbus (DSCC) commodity management facility. DLA\u27 5 blanket application of its variation of the Economic Order Quantity (EOQ) requirements model may not be appropriate for all levels of demand, possibly suboptimizing DLA\u27s desire to minimize inventory costs while still providing an appropriate level of customer service. Simulation analyses of the DLA EOQ requirements model, the Silver-Meal heuristic, and Periodic Order Quantity models were conducted to examine which dynamic lot-sizing model is more effective in minimizing inventory costs and levels for different levels of item demand. The Periodic Order Quantity model provided lower inventory levels and total variable costs than the DLA EOQ and the Silver-Meal models for the medium demand category. The DLA EOQ requirements model was found to provide lower inventory levels and total variable costs than either the POQ or the Silver-Meal models in the low and high demand categories

Joint Power and Blocklength Optimization for URLLC in a Factory Automation Scenario

Ultra-reliable and low-latency communication (URLLC) is one of three pillar applications defined in the fifth generation new radio (5G NR), and its research is still in its infancy due to the difficulties in guaranteeing extremely high reliability (say 10 -9 packet loss probability) and low latency (say 1 ms) simultaneously. In URLLC, short packet transmission is adopted to reduce latency, such that conventional Shannon's capacity formula is no longer applicable, and the achievable data rate in finite blocklength becomes a complex expression with respect to the decoding error probability and the blocklength. To provide URLLC service in a factory automation scenario, we consider that the central controller transmits different packets to a robot and an actuator, where the actuator is located far from the controller, and the robot can move between the controller and the actuator. In this scenario, we consider four fundamental downlink transmission schemes, including orthogonal multiple access (OMA), non-orthogonal multiple access (NOMA), relay-assisted, and cooperative NOMA (C-NOMA) schemes. For all these transmission schemes, we aim for jointly optimizing the blocklength and power allocation to minimize the decoding error probability of the actuator subject to the reliability requirement of the robot, the total energy constraints, as well as the latency constraints. We further develop low-complexity algorithms to address the optimization problems for each transmission scheme. For the general case with more than two devices, we also develop a low-complexity efficient algorithm for the OMA scheme. Our results show that the relay-assisted transmission significantly outperforms the OMA scheme, while the NOMA scheme performs well when the blocklength is very limited. We further show that the relay-assisted transmission has superior performance over the C-NOMA scheme due to larger feasible region of the former scheme

Evaluation of reliability modeling tools for advanced fault tolerant systems

The Computer Aided Reliability Estimation (CARE III) and Automated Reliability Interactice Estimation System (ARIES 82) reliability tools for application to advanced fault tolerance aerospace systems were evaluated. To determine reliability modeling requirements, the evaluation focused on the Draper Laboratories' Advanced Information Processing System (AIPS) architecture as an example architecture for fault tolerance aerospace systems. Advantages and limitations were identified for each reliability evaluation tool. The CARE III program was designed primarily for analyzing ultrareliable flight control systems. The ARIES 82 program's primary use was to support university research and teaching. Both CARE III and ARIES 82 were not suited for determining the reliability of complex nodal networks of the type used to interconnect processing sites in the AIPS architecture. It was concluded that ARIES was not suitable for modeling advanced fault tolerant systems. It was further concluded that subject to some limitations (the difficulty in modeling systems with unpowered spare modules, systems where equipment maintenance must be considered, systems where failure depends on the sequence in which faults occurred, and systems where multiple faults greater than a double near coincident faults must be considered), CARE III is best suited for evaluating the reliability of advanced tolerant systems for air transport

A Plan and Guide for the Implementation of a Computer Curriculum at Southeast Fountain Elementary School

This project was developed to provide an orderly plan for the introduction of microcomputers into the total curriculum. A computer curriculum was developed that became a vibrant part of the total experience at the elementary level. The uniqueness of an elementary curriculum has been the manner in which each subject area complemented the other. Science, for example, has not been taught as an independent content area. It has been taught as an extension of the reading program. Also computer instruction must be blended with the other disciplines. It was the purpose of this study (1) to show a plan for implementation of microcomputer instruction as one of the basics within the total elementary curriculum; (2) to provide a teaching guide for implementation of microcomputer instruction; (3) to indicate the appropriate areas of the established curriculum for microcomputers; and (4) to present the·goals and objectives for a microcomputer program. The completion of this project has resulted from a review of current research literature, an inspection of other existing computer curricula, and contacts with specialists within the computer field for assistance. Special assistance was given from representatives of the Indiana Department of Public Instruction, the Technical Assistance Center Region II, and Radio Shack Computer Center of Indianapolis, Indiana. The final result of this project was a method for the integration of microcomputers into the elementary curriculum. This study provided the vehicle for the accomplishment of goals and objectives in the areas of programming and computer literacy. This project was designed and implemented for the 1983-84 school year at the Southeast Fountain Elementary School

The Third Air Force/NASA Symposium on Recent Advances in Multidisciplinary Analysis and Optimization

The third Air Force/NASA Symposium on Recent Advances in Multidisciplinary Analysis and Optimization was held on 24-26 Sept. 1990. Sessions were on the following topics: dynamics and controls; multilevel optimization; sensitivity analysis; aerodynamic design software systems; optimization theory; analysis and design; shape optimization; vehicle components; structural optimization; aeroelasticity; artificial intelligence; multidisciplinary optimization; and composites

LLV - Lunar Logistics Vehicle Final report

Design of unmanned space vehicle for landing 2500 pound payload on moo

Team learning in a undergraduate setting in Croatia

This study focused on team learning at an undergraduate school environment. The researcher focused on a city in Croatia called Dubrovnik. The school is American College and consists of English speaking students that are composed of mostly Croatian descent. These students are Hospitality and Tourism majors and are eventually going to help the tourism economy after they graduate. This research contrasted student\u27s performance in one individual lesson plan in two different classes. One class is presented the material through the traditional lecture and the other class is presented the material through teams and collaborative learning. The two classes were given a pre-test and a post-test. These studies focused on results on the tests and are analyzed. The researcher hypothesizes that there will be an increase in the post-test scores in the team learning class that is higher than the traditional learning class. This is assuming that the pre-test scores in both classes are the same. The review of literature focused on information found on the subject of team learning and the benefits that students and teachers acquire from this way of learning

Contract Design for Collaborative Response to Service Disruptions

This dissertation studies firms' strategic interactions in anticipation of random service disruption following technology failure. In particular it is aimed at understanding how contracting decisions between a vendor and one or multiple clients affect the firms' subsequent decisions to ensure disruption response and recovery are managed as efficiently as possible. This dissertation consists of three studies that were written as standalone papers seeking to contribute to the literature on contract design and technology management in operations management. Together, the three studies justify the importance of structuring the right incentives to mitigate disruption risks. In the first study we contribute to this literature by means of an analytical model which we use to examine how a client and vendor should balance investments in response capacity when both parties' efforts are critical in resolving disruption and each may have different risk preferences. We study the difference in the client's optimal expected utility between a case in which investment in response capacity is observable and a case in which it is not and refer to the difference in outcomes between the two cases as the cost of complexity. Firstly, we show that the cost of complexity to the client is decreasing in the risk aversion of vendor but increasing in her own risk aversion. Secondly, we find that a larger difference in risk aversion between a client and vendor leads to underinvestment in system uptime in case the client's investment is observable, yet the opposite happens when the client’s investment is not observable. In the second study we further examine the context of the first study through a controlled experiment. We examine how differences in risk aversion and access to information on a contracting partner’s risk preferences interact in affecting contracting and investment decisions between the client and vendor. Comparing subject decisions with the conditionally optimal benchmarks we arrive at two observations that highlight possible heuristic decision biases. Firstly, subjects tend to set and hold on to an inefficiently high investment level even though it is theoretically optimal to adjust decisions under changing differences in risk preferences. Secondly, subjects tend to set and hold on to a penalty that is too high when interacting with more risk averse vendors and too low in case the vendor is equally risk averse. Furthermore, cognitive feedback on the vendor’s risk aversion appears to have counterproductive effects on subject’s performance in the experiment, suggesting cognitive overload can have a reinforcing effect on the heuristic decision biases observed. In the third study we construct a new analytical model to examine the effect of contract design on a provider's response capacity allocation in a setting where multiple clients may be disrupted and available response capacity is limited. The results show that while clients may be incentivized to identify and report network disruptions, competition for scarce emergency resources and the required investment in understanding their own exposure may incentivize clients to deliberately miscommunicate with the vendor.This work was supported by the Economic and Social Research Council [Award No. ES/J500033/1]. Additional funding was provided by Cambridge Judge Business School and Downing College