760 research outputs found

    A New Uncertainty Calculus For Rule-Based Expert Systems

    Get PDF
    The solution of non-deterministic expert systems consists of two components –the solution reached and a calculated measure of belief in each solution. This measure of belief is often the most critical factor in analyzing the solution. Unfortunately, as this paper reviews, the issue of how best to implement uncertainty calculi in expert systems has never been settled. Some popular rule-based approaches have in fact been shown to produce results no better than random guessing. To improve the accuracy of rule-based systems, we propose a new calculus we call gamma factors. This calculus combines ideas from two popular certainty factor calculi the product method, and the probability sum method. It includes a tuning mechanism which the expert can use in a rule pre-processing step to compensate for dependent parallel evidence combination

    Inexpensive Intelligence Using Procedural Propositional Logic

    Get PDF
    Implementations of inference engine systems invoke many costs, including the cost of the inference engine itself, the cost of integrating the inference engine, and the cost of specialized personnel needed to create and maintain the system. These costs make a very high return on investment a criterion for incorporating these systems into the corporate portfolio of applications and technologies. Recently, the No Inference Engine Theory (NIET) [8] has been developed for creating procedural propositional logic rule-based systems. The NIET systems are implemented in traditional procedural languages such as C++ and do not need an inference engine or proprietary languages, thus eliminating the cost of the inference engine, the cost of integrating the system, and the cost for knowledge of a proprietary language. In addition, these procedural systems are an order of magnitude faster [8] than inference systems and maintain linear performance. For problems using propositional logic, the procedural systems described in this paper offer dramatically lower costs, higher performance, and ease of integration. Lowering the external costs and eliminating the need for specialized skills should make NIET systems more profitable and lead to the wider use of propositional logic systems in business

    Students And Faculty Perceptions Of Communications Channels: A Comparison Of Survey Results

    Get PDF
    Individual communication between faculty and students outside of the classroom is one of the cornerstones of education. This survey examines the students and faculty perceptions of three communications media for several communication tasks that occur between students and faculty. A random sample of 449 students (undergraduate and graduate, full-time and part-time) which represents 10% of the population at a small Texas state university were invited to participate in a survey that elicited their perceptions on the effectiveness of face-to-face (office hours), e-mail and telephone communication. Similarly a random sample of 49 professors, which represents 32 % of the faculty population, was used to test several hypotheses. In this survey, the relevant results supported by some nonparametric statistical analyses are that at each media channel the "bootstrapped" confidence intervals estimates for the percentages in communications-time preferences of students and faculty were very similar, or without a significant difference. In addition, students and faculty expressed simultaneously (criteria of convergence) the same preference-level about e-mail for convenience and efficiency. Office hours were preferred for confidentiality, confrontation and emotional support. Equal preference about e-mail and office hours was expressed by both groups of study for the criteria: accuracy and overall effectiveness

    Work Motivation, Personality, and Culture: Comparing Australia and India

    Get PDF
    The influences of motivation and personality in relation to performance have been examined extensively in the research literature, but there has been only limited attention given to the influence of these facets on performance across cultures. There is an increasing use of international resources and alliances aimed at better economic management in many global companies, but more needs to be known about how cultural issues are related to individual motivation, personality and perceptions of performance. Moreover, there are several theories of motivation, but the transferability of these theories to different cultures has been questioned. Thus, a model of motivation, personality characteristics and cultural differences influencing performance is proposed and will be tested in a cross-cultural comparison. Specifically, motivational influences, personality characteristics and cultural differences in Australia and India will be examined in relation to performance in two contexts, the first, in the educational setting dealing with students and their attitudes and approaches, and the second, in the workplace setting dealing with workers in their attitudes and approaches. It is hoped the findings will have both theoretical implications for the model of motivation-personality-culture- performance and practical implications for selection, training, development and compensation in dealing with a global workforce. The current paper reports the main basis for the research to come, outlining the importance of understanding the India-Australia similarities and differences in personality and motivation, and indicates what the implications for cross-cultural relationships are

    Lexan Linear Shaped Charge Holder with Magnets and Backing Plate

    Get PDF
    A method was developed for cutting a fabric structural member in an inflatable module, without damaging the internal structure of the module, using linear shaped charge. Lexan and magnets are used in a charge holder to precisely position the linear shaped charge over the desired cut area. Two types of charge holders have been designed, each with its own backing plate. One holder cuts fabric straps in the vertical configuration, and the other charge holder cuts fabric straps in the horizontal configuration

    Shock formation and the ideal shape of ramp compression waves

    Full text link
    We derive expressions for shock formation based on the local curvature of the flow characteristics during dynamic compression. Given a specific ramp adiabat, calculated for instance from the equation of state for a substance, the ideal nonlinear shape for an applied ramp loading history can be determined. We discuss the region affected by lateral release, which can be presented in compact form for the ideal loading history. Example calculations are given for representative metals and plastic ablators. Continuum dynamics (hydrocode) simulations were in good agreement with the algebraic forms. Example applications are presented for several classes of laser-loading experiment, identifying conditions where shocks are desired but not formed, and where long duration ramps are desired

    Seroconversion of Raccoons Following Two Oral Rabies Vaccination Baiting Strategies

    Get PDF
    Seroprevalence of rabies virus neutralizing antibodies (rVNA) in raccoons (Procyon lotor) following oral rabies vaccination (ORV) with RABORAL V-RG® in the United States has annually averaged 30% since 1997, a level that is unlikely to successfully interrupt rabies transmission in raccoon populations. A longitudinal ORV zone is maintained in the eastern United States with raccoon variant rabies established east of the zone but absent to the west. However, questions remain regarding the effect of the bait application strategy towards achieving optimal population immunity. We estimated the number of ORV baits/km2 of raccoon home range and calculated rVNA seroprevalence following 2 ORV baiting strategies: cluster baiting (≤10 baits dropped at a time) via helicopter and hand distribution of individual baits at regular intervals along roads and trails in suburban Chattanooga, Tennessee, USA, during fall 2013 and 2014. We applied baits at 75 baits/km2 under both strategies. We established 6 1-km2 cells in each treatment area, and fitted ≤2 raccoons with global positioning system collars in each cell. We trapped and sampled ≤25 raccoons in each study cell pre- and post-ORV application for rVNA analysis. Overall raccoon home range and core area estimates were 80.7 ha and 17.5 ha, respectively (n=36). Average bait application for home ranges (n=32 home ranges that received bait) was 80.9 baits/km2 for helicopter baiting and 63.6 baits/km2 for hand baiting sites. Average bait application for core areas was 104.7 baits/km2 for helicopter baiting and 69.2 baits/ km2 for hand baiting sites. All home ranges were baited in both treatment areas, whereas 10/18 and 13/14 core areas were baited in the helicopter and hand distribution sites, respectively. Overall, helicopter cluster ORV delivered more baits/km2 of raccoon home range than hand distribution but was less effective in reaching core areas. Seroprevalence did not change as a function of baiting strategy (helicopter vs. hand baiting). The average overall increase in seroprevalence following ORV application was 8.9%. Evaluation of additional strategies are needed because both methods failed to achieve herd immunity necessary to disrupt rabies transmission in raccoons

    The SINS Survey: Broad Emission Lines in High-Redshift Star-Forming Galaxies

    Get PDF
    High signal-to-noise, representative spectra of star-forming galaxies at z~2, obtained via stacking, reveal a high-velocity component underneath the narrow H-alpha and [NII] emission lines. When modeled as a single Gaussian, this broad component has FWHM > 1500 km/s; when modeled as broad wings on the H-alpha and [NII] features, it has FWHM > 500 km/s. This feature is preferentially found in the more massive and more rapidly star-forming systems, which also tend to be older and larger galaxies. We interpret this emission as evidence of either powerful starburst-driven galactic winds or active supermassive black holes. If galactic winds are responsible for the broad emission, the observed luminosity and velocity of this gas imply mass outflow rates comparable to the star formation rate. On the other hand, if the broad line regions of active black holes account for the broad feature, the corresponding black holes masses are estimated to be an order of magnitude lower than those predicted by local scaling relations, suggesting a delayed assembly of supermassive black holes with respect to their host bulges.Comment: 11 pages, 5 figures. Accepted version, incorporating referee comments, including changes to title, abstract, figures, and discussion sectio
    • …
    corecore