Resident database interfaces to the DAVID system, a heterogeneous distributed database management system

A methodology for building interfaces of resident database management systems to a heterogeneous distributed database management system under development at NASA, the DAVID system, was developed. The feasibility of that methodology was demonstrated by construction of the software necessary to perform the interface task. The interface terminology developed in the course of this research is presented. The work performed and the results are summarized

A generalized strategy for building resident database interfaces

A strategy for building resident interfaces to host heterogeneous distributed data base management systems is developed. The strategy is used to construct several interfaces. A set of guidelines is developed for users to construct their own interfaces

Improvement of speed response in four-phase DC–DC converter switching using two shunt voltage-source

This study proposes a technique that is able to improve the speed response of a four-phase DC–DC converter switching. The basic concept of the proposed technique is the inclusion of two shunt-connected voltage sources in series to the converter system. Using a higher input voltage to drive the load, a higher current per microsecond output system will be obtained and reverts to its nominal input upon obtaining desired references. Thus, the transient response observed when using this proposed technique is found to be much faster when compared to the conventional converter. Moreover, this technique is easily implemented as it requires only an additional voltage source, power switch, and power diode. The integrated model of the two shunt voltage-source in a four-phase DC–DC converter was simulated in MATLAB/Simulink and validated against the experimental results of a laboratory prototype, 600 W four-phase DC–DC converter. The novelty of this proposed technique is its ability to provide faster operations for critical loads applications, lower output capacitor and lower operating frequency

Measuring usability for application software using the quality in use integration measurement model

User interfaces of application software are designed to make user interaction as efficient and as simple as possible. Market accessibility of any application software is determined by the usability of its user interfaces. A poorly designed user interface will have little value no matter how powerful the program is. Thus, it is significantly important to measure usability during the system development lifecycle in order to avoid user disappointment. Various methods and standards that help measure usability have been developed. However, these methods define usability inconsistently, which makes software engineers hesitant in implementing these methods or standards. The Quality in Use Integrated Measurement (QUIM) model is a consolidated approach for measuring usability through 10 factors, 26 criteria, and 127 metrics. It decomposes usability into factors, criteria, and metrics, and it is a hierarchical model that helps developers with no or little background of usability metrics. Among 127 metrics of QUIM, essential efficiency (EE) is the most specific metric used to measure the usability of user interfaces through an equation. This study involves a comparative analysis between three case studies that use the QUIM model to measure usability in terms of EE for three case studies: (1) Public University Registration System, (2) Restaurant Menu Ordering System, and (3) ATM system. A comparison is made based on the percentage of EE for each element of the use cases in each use case diagram. The results obtained revealed that the user interface design for Restaurant Menu Ordering System scored the highest percentage of EE, thus proving to be the most user-friendly application software among its counterparts

Low velocity impact response of rc beam with artificial polyethylene aggregate as concrete block infill

In structural design, an ideal situation for saving materials would be to reduce the weight of the structure without having to compromise on its strength and serviceability. A new lightweight composite reinforced concrete section was developed with a novel use of a lightweight concrete block as infill utilizing Artificial Polyethylene Aggregate (APEA and MAPEA). The concrete near the neutral axis acts as a stress transfer medium between the compression and tension zones. Partial replacement of the concrete near the neutral axis could create a reduction in weight and savings in the use of materials. In this experimental work, APEA and MAPEA were utilized as replacement for normal aggregates (NA) at percentages of 0%, 3%, 6%, and 9%, 12%, and 100% in the concrete mix. In this study, the concrete block infill uses the 100% MAPEA as a replacement for coarse aggregate. A total of sixteen beams were prepared measuring 170 mm × 250 mm × 1000 mm, in which four specimens were used as control samples (NRC) and twelve specimens were the reinforced concrete beam incorporated with different size of concrete block infill (RCAI) consisting of 100% MAPEA. All beams were tested with 100 kg steel weight dropped vertically from a height of 0.6 m and 1.54 m, which was equivalent to 3.5 m/s and 5.5 m/s respectively. Based on the experimental results, the impact force, displacement and crack patterns were affected by the impact load. For RCAI specimens, the impact force was larger but smaller displacement value was observed, compared to the NRC specimens. Furthermore, the width of the cracks generated in the RCAI specimens near the mid-span was less than that on the NRC specimen. All experiment results were validated against FEM. The transient impact force histories, displacement and crack patterns obtained from FEM matched reasonably well with the experiment results. The error reported a range of 1% to 15%. The results showed that the proposed use of concrete block infill produced desirable results under the impact loads. The main advantages of the concrete block infill that utilized MAPEA from waste plastic bags due to the weight reduction about 6% in the concrete beams

Moa and the multi-model architecture: a new perspective on XNF2

Advanced non-traditional application domains such as geographic information systems and digital library systems demand advanced data management support. In an effort to cope with this demand, we present the concept of a novel multi-model DBMS architecture which provides evaluation of queries on complexly structured data without sacrificing efficiency. A vital role in this architecture is played by the Moa language featuring a nested relational data model based on XNF2, in which we placed renewed interest. Furthermore, extensibility in Moa avoids optimization obstacles due to black-box treatment of ADTs. The combination of a mapping of queries on complexly structured data to an efficient physical algebra expression via a nested relational algebra, extensibility open to optimization, and the consequently better integration of domain-specific algorithms, makes that the Moa system can efficiently and effectively handle complex queries from non-traditional application domains

The NBS data management technology program

The National Bureau of Standards (NBS) Data Management Technology Program is discussed. The NBS Data Management Technology Program addresses major problems encountered during the following stages of an application's lifetime: requirements analysis and data base design, system selection and implementation, operations management and conversion. Products developed include standard software specifications, guides to best practice, standard data elements and representations, and reports documenting the experiences of other organizations as they attempt to improve the management of their computing resources. Data base Laboratory facilities are maintained for the investigation and analysis of state of the art data base technology. These facilities support collaborative testing with researchers, vendors, users, and standards developers

Technological Spaces: An Initial Appraisal

In this paper, we propose a high level view of technological spaces (TS) and relations among these spaces. A technological space is a working context with a set of associated concepts, body of knowledge, tools, required skills, and possibilities. It is often associated to a given user community with shared know-how, educational support, common literature and even workshop and conference regular meetings. Although it is difficult to give a precise definition, some TSs can be easily identified, e.g. the XML TS, the DBMS TS, the abstract syntax TS, the meta-model (OMG/MDA) TS, etc. The purpose of our work is not to define an abstract theory of technological spaces, but to figure out how to work more efficiently by using the best possibilities of each technology. To do so, we need a basic understanding of the similarities and differences between various TSs, and also of the possible operational bridges that will allow transferring the results obtained in one TS to other TS. We hope that the presented industrial vision may help us putting forward the idea that there could be more cooperation than competition among alternative technologies. Furthermore, as the spectrum of such available technologies is rapidly broadening, the necessity to offer clear guidelines when choosing practical solutions to engineering problems is becoming a must, not only for teachers but for project leaders as well

Special Libraries, July-August 1977

Volume 68, Issue 7-8https://scholarworks.sjsu.edu/sla_sl_1977/1005/thumbnail.jp