A study of discrete control signal fault conditions in the shuttle DPS

An analysis of the effects of discrete failures on the data processing subsystem is presented. A functional description of each discrete together with a list of software modules that use this discrete are included. A qualitative description of the consequences that may ensue due to discrete failures is given followed by a probabilistic reliability analysis of the data processing subsystem. Based on the investigation conducted, recommendations were made to improve the reliability of the subsystem

Quantitative risk assessment using Monte Carlo and dynamic process simulation

Currently, the concern about the industrial risk is a key issue to implement any technology process or to improve the industry competitiveness. In this sense, the risk concept may be considered as the main tool to anticipate behaviors that can lead to further problems. Considering the process industry, different risk analysis techniques are employed to identify hazardous events, to estimate their frequencies and severities, and to characterize the risk, being such tools the best ones to improve the industrial safety. Knowing that, the present Thesis discusses these risk topics to propose four main contributions: (i) new procedure to identify hazardous events; (ii) new procedures to quantify frequency; (iii) new risk definition and representation; and (iv) a method to integrate the proposed procedures to manage a complete risk assessment management. The idea behind the contributions is to use computational tools in new techniques with improved results about the operational risk, helping its obtainment and understanding. Thus, based on a new risk definition that allow better relation between the developed analysis, process simulations are employed to identify hazardous events and Monte Carlo simulations are employed to estimate frequency and to generate a new risk representation characterized by a severity x time x frequency surface. Despite all contributions has its particularity and importance for the risk analyses development, as final contribution, the presented Thesis apply all developed techniques in a case study, proposing an innovative risk assessment procedure.Atualmente, a preocupação com o risco industrial é um ponto chave para implantação de uma nova tecnologia ou para um melhor posicionamento competitivo. Neste sentido, a ideia de risco pode ser considerada como o principal recurso para antever situações que podem gerar problemas futuros. Considerando a indústria de processos, diferentes técnicas de análise de riscos são utilizadas para identificar eventos perigosos, estimar suas frequências e severidades e caracterizar o risco, sendo essas as principais ferramentas para o aumento da segurança industrial. Sabendo disso, a presente tese aborda tais tópicos e propõe quatro contribuições principais: (i) novo procedimento para identificação de eventos perigosos; (ii) novos procedimentos para quantificação de frequência; (iii) nova definição e representação de risco e (iv) um método para integrar os procedimentos propostos em uma avaliação quantitativa de risco completa. A ideia por trás destas contribuições é utilizar procedimentos computacionais que geram resultados mais acurados sobre o risco de uma operação, ajudando em seu entendimento e na obtenção de seu valor. Assim, baseado em um novo conceito de risco que melhor relaciona as análises desenvolvidas, simulações de processos são utilizadas para identificação de eventos perigosos e simulações de Monte Carlo são utilizadas para estimativa de frequência e gerar uma nova representação de risco caracterizada por uma superfície com eixos frequência x severidade x tempo. Apesar de cada contribuição ter sua particularidade e importância para o desenvolvimento das técnicas de análise de risco, como contribuição final, a presente tese aplica todas as técnicas desenvolvidas em um estudo de caso, apresentando assim uma avaliação de risco inovadora

Surveyor spacecraft system - Surveyor 6 flight performance Final report

Surveyor 6 spacecraft flight performance characteristics, including data on television equipment, alpha scattering experiment, and powered flight translatio

OEXP Analysis Tools Workshop

This publication summarizes the software needs and available analysis tools presented at the OEXP Analysis Tools Workshop held at the NASA Langley Research Center, Hampton, Virginia on June 21 to 22, 1988. The objective of the workshop was to identify available spacecraft system (and subsystem) analysis and engineering design tools, and mission planning and analysis software that could be used for various NASA Office of Exploration (code Z) studies, specifically lunar and Mars missions

Simulation verification techniques study

Results are summarized of the simulation verification techniques study which consisted of two tasks: to develop techniques for simulator hardware checkout and to develop techniques for simulation performance verification (validation). The hardware verification task involved definition of simulation hardware (hardware units and integrated simulator configurations), survey of current hardware self-test techniques, and definition of hardware and software techniques for checkout of simulator subsystems. The performance verification task included definition of simulation performance parameters (and critical performance parameters), definition of methods for establishing standards of performance (sources of reference data or validation), and definition of methods for validating performance. Both major tasks included definition of verification software and assessment of verification data base impact. An annotated bibliography of all documents generated during this study is provided

Aerospace Medicine and Biology: A continuing bibliography, supplement 191

A bibliographical list of 182 reports, articles, and other documents introduced into the NASA scientific and technical information system in February 1979 is presented

Technical approaches for measurement of human errors

Human error is a significant contributing factor in a very high proportion of civil transport, general aviation, and rotorcraft accidents. The technical details of a variety of proven approaches for the measurement of human errors in the context of the national airspace system are presented. Unobtrusive measurements suitable for cockpit operations and procedures in part of full mission simulation are emphasized. Procedure, system performance, and human operator centered measurements are discussed as they apply to the manual control, communication, supervisory, and monitoring tasks which are relevant to aviation operations

INTEROPERABILITY FOR MODELING AND SIMULATION IN MARITIME EXTENDED FRAMEWORK

This thesis reports on the most relevant researches performed during the years of the Ph.D. at the Genova University and within the Simulation Team. The researches have been performed according to M&S well known recognized standards. The studies performed on interoperable simulation cover all the environments of the Extended Maritime Framework, namely Sea Surface, Underwater, Air, Coast & Land, Space and Cyber Space. The applications cover both the civil and defence domain. The aim is to demonstrate the potential of M&S applications for the Extended Maritime Framework, applied to innovative unmanned vehicles as well as to traditional assets, human personnel included. A variety of techniques and methodology have been fruitfully applied in the researches, ranging from interoperable simulation, discrete event simulation, stochastic simulation, artificial intelligence, decision support system and even human behaviour modelling

IUS guidance algorithm gamma guide assessment

The Gamma Guidance Algorithm which controls the inertial upper stage is described. The results of an independent assessment of the algorithm's performance in satisfying the NASA missions' targeting objectives are presented. The results of a launch window analysis for a Galileo mission, and suggested improvements are included