75 research outputs found

    Data base architecture for instrument characteristics critical to spacecraft conceptual design

    Get PDF
    Spacecraft designs are driven by the payloads and mission requirements that they support. Many of the payload characteristics, such as mass, power requirements, communication requirements, moving parts, and so forth directly affect the choices for the spacecraft structural configuration and its subsystem design and component selection. The conceptual design process, which translates mission requirements into early spacecraft concepts, must be tolerant of frequent changes in the payload complement and resource requirements. A computer data base was designed and implemented for the purposes of containing the payload characteristics pertinent for spacecraft conceptual design, tracking the evolution of these payloads over time, and enabling the integration of the payload data with engineering analysis programs for improving the efficiency in producing spacecraft designs. In-house tools were used for constructing the data base and for performing the actual integration with an existing program for optimizing payload mass locations on the spacecraft

    National Aeronautics and Space Administration fundamental research program. Information utilization and evaluation

    Get PDF
    In the second half of the 1980's NASA can expect to face difficult choices among alternative fundamental and applied research, and development projects that could potentially lead to improvements in the information systems used to manage renewable resources. The working group on information utilization and evaluation believes that effective choices cannot be made without a better understanding of the current and prospective problems and opportunities involved in the application of remote sensing to improve renewable research information systems. A renewable resources information system is defined in a broad context to include a flow of data/information from: acquisition through processing, storage, integration with other data, analysis, graphic presentation, decision making, and assessment of the affects of those decisions

    Economic data bank management in a developing nation

    Get PDF
    This dissertation describes the results of a research project which was undertaken at Loughborough University of Technology. The basic objectives of the research project were: (1) to investigate the management elements required for organising the development of an Economic Data Bank (EDB), with particular emphasis on the requirements of a developing nation; (2) to investigate the sociological, political and technical implications associated with organising the development of an EDB in a developing nation. A theoretical framework was established for this study. This was dene after an extensive search and review of literature was performed in the areas of data and data base management systems, management information systems, and computer technology in general. [Continues.

    Object oriented database management systems

    Get PDF
    Modern data intensive applications, such as multimedia systems require the ability to store and manipulate complex data. The classical Database Management Systems (DBMS), such as relational databases, cannot support these types of applications efficiently. This dissertation presents the salient features of Object Database Management Systems (ODBMS) and Persistent Programming Languages (PPL), which have been developed to address the data management needs of these difficult applications. An 'impedance mismatch' problem occurs in the traditional DBMS because the data and computational aspects of the application are implemented using two different systems, that of query and programming language. PPL's provide facilities to cater for both persistent and transient data within the same language, hence avoiding the impedance mismatch problem. This dissertation presents a method of implementing a PPL by extending the language C++ with pre-compiled classes. The classes are first developed and then used to implement object persistence in two simple applications.ComputingM. Sc. (Information Systems

    National Aeronautics and Space Administration's (NASA) Automated Information Security Handbook

    Get PDF
    The NASA Automated Information Security Handbook provides NASA's overall approach to automated information systems security including discussions of such aspects as: program goals and objectives, assignment of responsibilities, risk assessment, foreign national access, contingency planning and disaster recovery, awareness training, procurement, certification, planning, and special considerations for microcomputers

    An Approach to Data Description and Conversion

    Get PDF
    Currently, the structure of stored data is determined implicitly by the software which accesses and processes it. This data structuring technology has given rise to two outstanding problems in data processing. First, there is the communication of the exact structure of data to users and machines, and secondly, the interchange of the data itself. This work contributed to overcoming these problems by developing a technique for describing the structure of data explicitly and independently of machines and software. This aim is reflected in the following objectives: 1) To understand data structures by developing a model which not only characterizes current data organizational techniques, but also provides a framework within which new data structures can be defined. 2) To use this model to develop a language which can explicitly describe the organization of data. 3) To use this model to study how data can be converted from one structure to another, with a view towards developing a method for describing data conversions. This model unifies the diverse area of data structures by including the record, file and storage organizations of data. Furthermore, the model clearly separates at each level the conceptual part, which is the logical structure imposed by a user, from the implementation part, which is the method by which the logical structure is I encoded as a binary representation. This separation leads to n straightforward mapping of a file onto storage. From an analysis of the state-of-the-art in data organization, it is shown that the model can express not only the data structures of current systems, but also certain useful generalizations which might well be produced by future systems. The model treats records as hierarchies of data items. These hierarchies are expressed by production systems based on a generalized notion of attribute-value pairs. Files are treated as graphs whose nodes are records. The connections between the nodes are expressed using a powerful production system which generates criteria for determining when any two records are to be linked. The structure of storage is generalized as a hierarchy since this structure is common to all storage media. The mapping of files onto storage is expressed in terms of rules for distributing the records of the file within the slots provided by the storage structure. The language, called Generalized Data Description Language (GDDL) is a realization of the model, and thus possesses all its capabilities . In particular, the language can describe the implementation of any aspect of a file as being dependent on any other aspect. The language is presented in an appendix in the form of a user\u27s manual. Data conversion is studied in terms of transforming data in one structure to another, where both structures are expressed in the model. This study shows that to fully specify a conversion the relationship between the components of the two structures must be specified. In certain cases, such as the reorganization of a file, this relationship can be very elaborate. A method is developed for specifying such relationships, and a corresponding capability is built into GDDL. Thus, WDL has the ability not only to fully describe data structures, but also to specify data conversion

    Considerations for a design and operations knowledge support system for Space Station Freedom

    Get PDF
    Engineering and operations of modern engineered systems depend critically upon detailed design and operations knowledge that is accurate and authoritative. A design and operations knowledge support system (DOKSS) is a modern computer-based information system providing knowledge about the creation, evolution, and growth of an engineered system. The purpose of a DOKSS is to provide convenient and effective access to this multifaceted information. The complexity of Space Station Freedom's (SSF's) systems, elements, interfaces, and organizations makes convenient access to design knowledge especially important, when compared to simpler systems. The life cycle length, being 30 or more years, adds a new dimension to space operations, maintenance, and evolution. Provided here is a review and discussion of design knowledge support systems to be delivered and operated as a critical part of the engineered system. A concept of a DOKSS for Space Station Freedom (SSF) is presented. This is followed by a detailed discussion of a DOKSS for the Lyndon B. Johnson Space Center and Work Package-2 portions of SSF

    Space station data system analysis/architecture study. Task 2: Options development, DR-5. Volume 2: Design options

    Get PDF
    The primary objective of Task 2 is the development of an information base that will support the conduct of trade studies and provide sufficient data to make key design/programmatic decisions. This includes: (1) the establishment of option categories that are most likely to influence Space Station Data System (SSDS) definition; (2) the identification of preferred options in each category; and (3) the characterization of these options with respect to performance attributes, constraints, cost and risk. This volume contains the options development for the design category. This category comprises alternative structures, configurations and techniques that can be used to develop designs that are responsive to the SSDS requirements. The specific areas discussed are software, including data base management and distributed operating systems; system architecture, including fault tolerance and system growth/automation/autonomy and system interfaces; time management; and system security/privacy. Also discussed are space communications and local area networking

    The UARS and open data concept and analysis study

    Get PDF
    Alternative concepts for a common design for the UARS and OPEN Central Data Handling Facility (CDHF) are offered. Costs for alternative implementations of the UARS designs are presented, showing that the system design does not restrict the implementation to a single manufacturer. Processing demands on the alternative UARS CDHF implementations are then discussed. With this information at hand together with estimates for OPEN processing demands, it is shown that any shortfall in system capability for OPEN support can be remedied by either component upgrades or array processing attachments rather than a system redesign. In addition to a common system design, it is shown that there is significant potential for common software design, especially in the areas of data management software and non-user-unique production software. Archiving the CDHF data are discussed. Following that, cost examples for several modes of communications between the CDHF and Remote User Facilities are presented. Technology application is discussed
    corecore