134 research outputs found
Maximal entropy solutions under prescribed mass and energy
No full textWe consider a non-local elliptic equation with exponential nonlinearity, closely related to the mean field Liouville equation. The motivation for this equation is a variational entropy maximization problem under prescribed mass and energy. We provide an unconditional existence proof in case of electrostatic (repulsive) self-interaction, and conditional existence and uniqueness in dimension two in the case of gravitational (attractive) self-interaction. (C) 2019 Elsevier Inc. All rights reserved
Development of a Chinese computer-assisted video instruction system
No full textThis research was designed to develop and investigate a Chinese interactive video instructional system with the use of a microcomputer. Studies in Taiwan have indicated that several major problems confront the teacher who attempts to design CAI courseware. The major difficulties are the need for Chinese input/output and the lack of authoring tools. Hence, the purpose of this project has been devoted to explore a model for using interactive video in education in Taiwan;The major task of this study was to develop the Chinese Interactive Video System (CIVS), a computer assisted video learning environment with Chinese characters display capability. Two components, a computer interface and an authoring program, were designed. An interactive video system interfaces a computer with a video cassette recorder (VCR), a slide projector, and a voice processor. The sequence of presenting the video lesson is under the control of the computer program. The computer is thus used to teach, query, remediate, or otherwise support the audio-visual lesson;The instructional options are organized through the use of editors, which are given the form of screen-displayed menus. The authoring program in the CIVS system consists of five editors: voice editor, graphics editor, character sets editor, test editor, and lesson script editor. The voice editor helps the author to organize the voice data and data-files; the Chinese Courseware Graphics Editor provides a menu with which users can compile their lesson frames; the character-sets editor allows the user to define special symbols; the test editor enables the author to create and update test items; and the lesson script editor provides the menu with which the author can build the script that forms the instructional presentation flow;The CIVS system utilizes a simple-to-follow prompting format that enables the designer to create video lessons with little or nor programming skills. Obviously, the idea and the model developed in this research represents an extension of studies regarding the implementation of computer-assisted instruction in Taiwan.</p
Estudio del impacto de la mezcla de los herbicidas glifosato y 2,4-D sobre comunidades microscópicas de agua dulce y la calidad del agua : aproximación ecotoxicológica en microcosmos y mesocosmos al aire libre
No full textEl objetivo general de esta tesis fue estudiar el impacto de los herbicidas glifosato, 2,4-D y su mezcla sobre las comunidades microbianas de los cuerpos de agua dulce, con énfasis en las comunidades autótrofas. Para ello, se utilizaron distintas aproximaciones experimentales. En primer lugar se realizaron experimentos en microcosmos en condiciones controladas de laboratorio, ensayando con comunidades fitoplantónicas consolidadas en estados contrastantes de turbidez y con la comunidad perifítica. En segundo lugar se realizaron dos experimentos en mesocosmos al aire libre utilizando agua en condiciones contrastantes, clara y turbia-orgánica, con el objetivo de estudiar la influencia de este factor sobre variables estructurales y funcionales. Los resultados obtenidos indican que los efectos de los herbicidas dependen de la forma en que se utilizan (principios activos vs formulados comerciales), del estado de turbidez del agua y sus comunidades, así como de la complejidad del sistema experimental estudiado. El efecto de la mezcla del glifosato y 2,4-D en proporción agronómica (1:0,45) fue mayormente aditivo, pero algunas variables mostraron antagonismo y sinergismo. Estos resultados resaltan la importancia de estudiar el impacto de los plaguicidas sobre sistemas de agua dulce en estados contrastantes, con comunidades establecidas complejas, a través del estudio de variables estructurales y funcionales.The general objective of this thesis was to study the impact of glyphosate and 2,4-D herbicides and their mixture on the microbial communities of freshwater bodies, with emphasis on autotrophic communities. Different methodological approaches were used to achieve this objective. First, experiments were carried out in microcosms under controlled laboratory conditions, testing consolidated phytoplantonic communities in contrasting turbidity states and with the periphyton community. Secondly, two experiments were carried out in out-door mesocosms using water in two contrasting conditions – clear and turbid-organic, with the aim of studying the influence of this factor on structural and functional variables. The results indicate that the effects of herbicides depend on the way they are used (active ingredients vs. commercial formulations), the state of turbidity of the water and their communities, as well as the complexity of the experimental system that is studied. The effect of the mixture of glyphosate and 2,4-D in agronomic ratio (1: 0.45) was mostly additive, but some variables showed antagonism and synergism. These results highlight the importance of studying the impact of pesticides on freshwater systems in contrasting states, with complex established communities, through the study of structural and functional variables.Fil: Lozano, Verónica Laura. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
Existence and non existence results for supercritical systems of Liouville-type equations on simply connected domains
No full textWe obtain a Pohozaev-type identity which yields a generalization to the systems
case of the well known scalar non-existence threshold for Liouville-type mean field equa-
tions on strictly starshaped domains. These newly derived non-existence results suggest that
in principle solutions could be find in a region of parameters far away from the subcritical
regime with respect to the vectorial Moser–Trudinger and Log-HLS inequalities found by
Chipot, Shafrir and Wolansky. Indeed, we succeed in proving that the Dirichlet problem for
cooperative Liouville systems admits solutions on “thin” simply connected domains in the
supercritical regime. This is an improvement of the existence theory for cooperative Liou-
ville systems since in that region solutions were known to exist only on multiply connected
domains. Finally, combining spectral elliptic estimates and Orlicz-spaces techniques with a
trick introduced by Wolansky we prove that these newly derived solutions are strict local
minimizers of the Moser–Trudinger-type and free-energy functionals
Inservice training for incorporating environmental education into the industrial/vocational education system at the secondary education level in Taiwan the ROC
No full textThe purpose of this study was to develop a sequential procedural steps of inservice training of environmental education for industrial/vocational senior high school teachers in Taiwan R.O.C. The study investigated the attitudes and needs of teachers in terms of inservice training for environmental education. It also investigated teachers' perceptions of content, formats, time preferences, teaching methods, and administrative support for inservice training. The samples of the study consisted of 381 industrial/vocational senior high school teachers in Taiwan R.O.C;Twelve hypotheses were tested at the 0.05 level of significance. Seven revealed significant difference and are listed by geographic area, gender, school level, and school type. There is a significant difference in respondents' perceptions regarding: (1) updating levels of environmental knowledge among teachers living in different areas, or between teachers representing different genders; or between teachers different school level; (2) need for inservice training program content among teachers living in different areas; (3) preference for particular organizations to deliver inservice training to teachers living in different areas; (4) time preferences for inservice training by teachers living in different areas; and (5) administrative support for inservice training between public school teachers and private school teachers;The following recommendations for conducting effective inservice training in environmental education were suggested: (1) either the Environmental Protection Administration Government (EPAG) of the R.O.C. or the Ministry of Education (MOE) conduct a needs assessment before any inservice training; (2) either EPAG or MOE set up additional environmental education centers in central, southern, and eastern Taiwan; (3) five courses be provided first into inservice training: (a) pollution and pollution prevention; (b) humans and natures; (c) choosing, obtaining, using, and evaluating environmental instructional materials and equipment; (d) coordinating and integrating abilities; and (e) problem-solving abilities for pollution prevention; (4) inservice training be provided in summer or winter sessions; (5) training formats be multifaceted; (6) MOE provide schools with sufficient budgets for teacher inservice training; (7) school principals allow teachers more release time for inservice training and support more professional development activities; (8) administrators be trained in environmental education; (9) teachers with a different majors be involved in inservice training in environmental education; and (10) evaluation be conducted after inservice training.</p
Effectiveness of microcomputer aided television troubleshooting instruction using digital image database
No full textA microcomputer-based imaging system for instructing television troubleshooting has become available. It mainly consisted of an television troubleshooting expert system software and a digital image processing board installed in a 386[superscript]' IBM PC/AT microcomputer. The teaching images were grabbed by a CCD video camera and processed with PCA image database packages;The expert system developed for this study provided a knowledge base which followed the rules of "proceduralized problem-solving" and consisted of a knowledge base, an image database, and an inference engine. The knowledge base included a library of decision-making rules, frames of troubleshooting procedures, and frames of learning units. The image database contained test patterns, block diagrams, stage circuits, and symptomatic pictures. The inference engine included a frame and rule interpreter, user commands, and a screen interface. The decision-making rules were organized with 'IF-THEN" logic. In order to simplify the diagnosis procedure, four criteria (raster, picture, color, and sound) were applied to analyze a defective television symptom;An experiment was conducted to test the effectiveness of this prototype instruction system. Thirty-six students were selected from the department of Industrial Education, National Taiwan Normal University, and randomly assigned to two groups each with equal members. The experimental group learned television troubleshooting with a microcomputer and the developed courseware, while the control group used traditional instruments to learn television troubleshooting. They were both given pretest, posttest, and skill test during class sessions;The achievement differences between these two groups were analyzed with the SAS packages. There was a significant achievement difference between the control group and the experimental group in learning television troubleshooting knowledge and skills. In addition, the time consumption difference for troubleshooting a defective symptom also reached a significant level. It was possible to say that the microcomputer-based television troubleshooting instruction using image database was more effective than traditional teaching method. To improve this system, a complete software and update hardware were encouraged.</p
The development of a mathematical model for technology transfer potential: a manufacturing industry case
No full textA mathematical model was developed to measure the degree of technology in a given country or countries. The model is based on the regression analysis incorporating a taxonomic method to measure the difference of technological development within a group of countries. Simple linear regression analysis was employed to identify the independent variables showing the strongest relationship to the dependent variable. These variables were then used in controlled studies to investigate causal relationships, i.e., to identify the importance of the technological characteristics influencing the technological level. Second, the independent variables most influencing the dependent variable were selected using the all-regression procedure. Third, taxonomic analysis was employed to classify, compare, and rank the levels of technological development. The resource mathematical model was investigated for developed industrial countries, newly industrializing countries, middle income countries, and less developing countries. Using the nation's data from the period of 1980-1986, the results show that as long as the industrial countries maintain economic prosperity, they will probably continue to dominate high technology. Thus, they may continue to be the primary resources of technology. On the other hand, the technological development in the less developed countries remains still in the earliest stage. Comparisons and ranking of technological development within individual countries are also analyzed.</p
Iowa State Journal of Research 51.4
No full textStoltzfus, W. Bryan. The taxonomy and biology of Eutreta (Diptera: Tephritidae). 369
Breiter, J., and J. Menne. Social studies curriculum and the elementary teacher. 439
Gimmel, D., A. Netusil, L. Schwenk, A. Sherick, R. Volker, and W. Wolansky. Long-term retention from audio-tutorial teaching. 465
Williams, D.D. A key to caryophyllaeid cestodes of Wisconsin fishes. 471</p
The roles of academic deans of land-grant universities by the year 2000
No full textThis study was designed to investigate the perceptions of deans and faculty members of land-grant universities regarding the roles of their academic deans by the year 2000. It was also designed to investigate the respondents' perceptions as to the need for formal preparation of those deans by the same time period;A questionnaire of four sections was generated and mailed to 196 randomly selected deans and faculty members across the contiguous United States as well as Alaska. The data analyses and hypotheses testings were done by utilizing the correlated and independent t-test procedures, the one-way analysis of variance (ANOVA) and the chi-square procedures;The conclusions from the findings of the study included the following, among others: (1) That the underlisted roles have been perceived as having potential importance by the year 2000 in the following order: institutional politics, administrative, financial, faculty, global education, enrollment management, student, and academic affairs. (2) That the respondents perceived that there would be no need for formal preparation of deans of land-grant universities by the year 2000;Based on the findings and conclusions of the research, the following are some of the recommendations that were made: (1) That academic deans should involve faculty members in planning for the future of their colleges and universities. (2) That deans should work on improving communications and relationships regarding the roles of conflicting perceptions. Diversified perceptions should be utilized as fountain of ideas for planning purposes. (3) That deans' search committees should incorporate global education and enrollment management roles into the academic deans' future job descriptions. (4) That prospective deans should be interviewed about their educational philosophy(ies) and vision in order to assess compatibility with formulated job description and college mission. (5) That short courses should be encouraged for professional advancement of academic deans as well as other senior higher education administrators instead of formal training. (6) That research on deanship should be made a continual exercise.</p
An investigation of trends and issues of technology education
No full textThe purpose of this study was to investigate the nature of the current technology education movement and its impacts, problems, directions, as well as prospects for future development of technology education;A survey questionnaire consisting of three parts was used for collecting the data pertaining to program characteristics, objectives, problems, solutions, and prospects of technology education. Factor analysis was performed to verify the underlying structure of the instrument. Four orthogonal factors were extracted from the analysis for philosophical objectives of technology education. These four factors were: (1) technological literacy, (2) conventional IA objective, (3) intellectual development, and (4) use of tools and machines;Six problem factors derived from factor analysis were labeled as: (1) teaching content, (2) perception of program, (3) teacher education program, (4) student recruitment, (5) facility, and (6) teacher shortage;Six solution factors for solving TE problems were also extracted from factor analysis. They included: (1) curriculum development, (2) public relations, (3) teacher education, (4) perspective teacher recruitment, (5) female student recruitment, and (6) facility planning and innovation;Three prospect factors were extracted from factor analysis and were identified as: (1) program quality and image, (2) facility and curriculum, and (3) graduate and enrollment. These derived factors were used for further hypothesis testing;Eight hypotheses were formulated and tested in this study;Results of the study indicated that the responses of the three subject groups were very uniform. Their perceptions on most of the objective, problem, solution, and prospect factors of technology education were not significantly different from one another;A technology education curriculum development framework was presented along with the teaching scope and sequence for K-12.</p
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