1,204 research outputs found
Structural Change in the U.S. Food Manufacturing Sector
This study examines the market structure-conduct-performance relationship for 48 four-digit SIC Food and Tobacco Processing Industries during the 1970s, 1980s and 1990s. The simultaneous-equation analyses are used to explore the relationship among price-cost margin (PCM), market concentration, advertising outlay, and various control variables. With an intertemporal setting, our findings provide evidence of structural changes over time in the U.S. food manufacturing sector and support some of the conventional SCP wisdoms, but challenge others.Agribusiness,
An Investigation of the Effects of Categorization and Discrimination Training on Auditory Perceptual Space
Psychophysical phenomena such as categorical perception and the perceptual magnet effect indicate that our auditory perceptual spaces are warped for some stimuli. This paper investigates the effects of two different kinds of training on auditory perceptual space. It is first shown that categorization training, in which subjects learn to identify stimuli within a particular frequency range as members of the same category, can lead to a decrease in sensitivity to stimuli in that category. This phenomenon is an example of acquired similarity and apparently has not been previously demonstrated for a category-relevant dimension. Discrimination training with the same set of stimuli was shown to have the opposite effect: subjects became more sensitive to differences in the stimuli presented during training. Further experiments investigated some of the conditions that are necessary to generate the acquired similarity found in the first experiment. The results of these experiments are used to evaluate two neural network models of the perceptual magnet effect. These models, in combination with our experimental results, are used to generate an experimentally testable hypothesis concerning changes in the brain's auditory maps under different training conditions.Alfred P. Sloan Foundation and the National institutes of Deafness and other Communication Disorders (R29 02852); Air Force Office of Scientific Research (F49620-98-1-0108
Explicating Factors that Foster Civic Engagement among Students
This paper investigates many facets of civic engagement by analyzing how college undergraduate students conceptualize civic engagement and by examining factors that predict greater student involvement in political, social, and community affairs.We administered a survey to college students at the beginning of fall, winter, and spring terms, 2001-02.We analyzed survey responses using a structural equation modeling (SEM) technique. The analysis examines how expectations of community and political efficacy, attitudes regarding citizen control of government, and attitudes toward diversity relate to the students’ civic engagement behaviors such as monthly volunteer hours, organizational participation, advocacy, voting, direct political action, and action to promote diversity and social justice in the community. The result of the SEM analysis indicates that expectations of efficacy significantly predict students’ direct political action, monthly volunteer hours, organizational participation, advocacy, and voting attitude. Students’ sense of control over public affairs significantly predicts organizational participation, advocacy, and voting attitude. The implications of these results are discussed in relation to curriculum design to foster civic engagement
Land use change detection with LANDSAT-2 data for monitoring and predicting regional water quality degradation
The author has identified the following significant results. Comparison between LANDSAT 1 and 2 imagery of Arkansas provided evidence of significant land use changes during the 1972-75 time period. Analysis of Arkansas historical water quality information has shown conclusively that whereas point source pollution generally can be detected by use of water quality data collected by state and federal agencies, sampling methodologies for nonpoint source contamination attributable to surface runoff are totally inadequate. The expensive undertaking of monitoring all nonpoint sources for numerous watersheds can be lessened by implementing LANDSAT change detection analyses
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A hierarchy fuzzy MCDM method for studying electronic marketing strategies in the information service industry
In this paper the impacts of Electronic Commerce {EC) on the international marketing strategies for the information service industries are studied. In seeking to blend humanistic concerns in this research with technological development by addressing challenges for deterministic attitudes, it also examines critical environmental factors relevant to Internet commerce in the changes of the international marketing environment. The needs for a new marketing paradigm for EC, which comes out of new trends of international electronic marketing, are also examined. The impacts of EC for the information service industry are discussed and a hierarchy fuzzy multicriteria decision-making (Fuzzy MCDM) method for evaluating the propagating EC market strategies is proposed. Finally, in order to show the practicability and usefulness in this method, an example is taken as a verifiable method. From the results of practical applications in evaluating the electronic marketing strategies, the proposed method is appropriate and appears to be ideal for a fuzzy environment
Reducing reversal errors in localizing the source of sound in virtual environment without head tracking
International audienceThis paper presents a study about the effect of using additional audio cueing and Head-Related Transfer Function (HRTF) on human performance in sound source localization task without using head movement. The existing techniques of sound spatialization generate reversal errors. We intend to reduce these errors by introducing sensory cues based on sound effects. We conducted and experimental study to evaluate the impact of additional cues in sound source localization task. The results showed the benefit of combining the additional cues and HRTF in terms of the localization accuracy and the reduction of reversal errors. This technique allows significant reduction of reversal errors compared to the use of the HRTF separately. For instance, this technique could be used to improve audio spatial alerting, spatial tracking and target detection in simulation applications when head movement is not included
Core-Level Spectroscopy of the Ni/W(110) Interface: Correlation of W Interfacial Core LevelShifts with First-Layer Ni Phases
We have measured W 4f7/2 core-level photoemission spectra from W(1 1 0) in the presence of Ni overlayers, from ∼0.2 to ∼3 monolayers. Interfacial core-level shifts associated with first-layer Ni phases have been identified: −230 ± 15 meV for the 1 × 1 pseudomorphic phase and −70 ± 7 meV for the 7 × 1 close-packed commensurate phase. At higher Ni coverages the interfacial core-level shift is −100 ± 10 meV. These shifts are analyzed using the partial-shift model of Nilsson et al. [Phys. Rev. B 38 (1988) 10357]; the analysis indicates that the difference in binding energies between the 1 × 1 and 7 × 1 phases has a large contribution from structural differences between the two phases
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