Attribute-Level Versioning: A Relational Mechanism for Version Storage and Retrieval

Data analysts today have at their disposal a seemingly endless supply of data and repositories hence, datasets from which to draw. New datasets become available daily thus making the choice of which dataset to use difficult. Furthermore, traditional data analysis has been conducted using structured data repositories such as relational database management systems (RDBMS). These systems, by their nature and design, prohibit duplication for indexed collections forcing analysts to choose one value for each of the available attributes for an item in the collection. Often analysts discover two or more datasets with information about the same entity. When combining this data and transforming it into a form that is usable in an RDBMS, analysts are forced to deconflict the collisions and choose a single value for each duplicated attribute containing differing values. This deconfliction is the source of a considerable amount of guesswork and speculation on the part of the analyst in the absence of professional intuition. One must consider what is lost by discarding those alternative values. Are there relationships between the conflicting datasets that have meaning? Is each dataset presenting a different and valid view of the entity or are the alternate values erroneous? If so, which values are erroneous? Is there a historical significance of the variances? The analysis of modern datasets requires the use of specialized algorithms and storage and retrieval mechanisms to identify, deconflict, and assimilate variances of attributes for each entity encountered. These variances, or versions of attribute values, contribute meaning to the evolution and analysis of the entity and its relationship to other entities. A new, distinct storage and retrieval mechanism will enable analysts to efficiently store, analyze, and retrieve the attribute versions without unnecessary complexity or additional alterations of the original or derived dataset schemas. This paper presents technologies and innovations that assist data analysts in discovering meaning within their data and preserving all of the original data for every entity in the RDBMS

Research Reports: 1988 NASA/ASEE Summer Faculty Fellowship Program

The basic objectives are to further the professional knowledge of qualified engineering and science faculty members; to stimulate an exchange of ideas between participants and NASA: to enrich and refresh the research and teaching activities of the participants' institutions; and to contribute to the research objectives of the NASA centers. Topics addressed include: cryogenics; thunderstorm simulation; computer techniques; computer assisted instruction; system analysis weather forecasting; rocket engine design; crystal growth; control systems design; turbine pumps for the Space Shuttle Main engine; electron mobility; heat transfer predictions; rotor dynamics; mathematical models; computational fluid dynamics; and structural analysis

Future Coal Supply for the World Energy Balance; Proceedings of the Third IIASA Conference on Energy Resources, November 28 - December 2, 1977

There is growing concern and interest in the re-emergence into the energy picture of "King Coal." Coal, as it is produced today and, still more, as it will be produced tomorrow and in the next century, has many new features. Reserves and resources are revised upward, by jumps greater than the total estimated world oil resources. Production techniques are shifting from fully automated underground mines to gigantic surface mines with annual capacities of some tens of millions of tons. Coal slurry pipelines will be used for transportation, and sophisticated processes can transform coal into almost any other fuel: gas, syncrude, methanol, gasoline, and so on. How do the various nations, whether producers or consumers or both, react to these changing conditions? And what could be the effects on the future world energy balance, and on a potential world coal market trying to compete with the world oil market? All these questions--and many others--were raised and dealt with during the Third IIASA Conference on Energy Resources, devoted to Future Coal Supply for the World Energy Balance. More than seventy experts from East and West--technicians, economists, futurologists, modelers--contributed. The papers presented in this book treat technical aspects and prospects and economic (national, international, and global) problems and perspectives