224 research outputs found
Freeware As An Advertisement
This paper examines the situation in which a monopolist offers freeware as an advertisement to increase the demand in order to maximize profit even though the existence of such freeware will reduce the power of the monopolist in the market. We prove that the successful application of freeware is dependent on the number of potential consumers and there exists an optimal quality design for freeware in this situation.Freeware; Software; Advertisement
Using a computerized data collection method to explore sketch map drawing sequence
Cognitive mapping has attracted immense interest from many fields, creating collaborative and cross-disciplinary research. The study of cognitive maps enjoyed almost two decades of growth, until its decline in the early 1980s. By the 1990s, the new cross-disciplinary exchange with computer science and information technology has renewed interest in the field, which may be the next wave of cognitive mapping research explosion. This study will, through the development of an innovative tool and an in depth analysis of cognitive maps, namely, sequence, search for links between sequence and other variables, namely sketch map type classification, sketch map drawing processes and differences between female and male sketch maps. The methodological tool, namely MMAPIT, was a different approach from past studies to collect sketch maps. MMAPIT was a combination of hardware (Tablet PC) and software that allowed subjects to draw their sketch map directly on the tablet and recorded the drawing process in audio and video format. The drawing process was transcribed producing the sequence or order each element was drawn. The sequence data not only generated new ways of examining sketch maps, they also produced results worthy of note of new methodology used and the pairing of unlikely results. There were four major findings from this study, namely the fish tail graphical pattern, six ways to draw sketch maps, division of the landmark element into subgroups, and differences found between female and male produced sketch maps. The fish tail is a pattern resulting from the graphical presentation of the proportion of elements drawn at each sequence. This pattern showed the increase of landmarks and the decrease of paths throughout the graph. A second use of sequence was a method to classify sketch maps into map types including sequential, spatial and hybrid maps. Sequences were also input into a software, namely ClustalW, to cluster groups of subjects with similar sequence strings. This method not only classified map types but also revealed that sketch maps can be drawn through recalling elements in six different ways. These six drawing methods all started with paths, suggesting their importance as a framework for sketch map building. The recall order of elements is part of a larger study in psychology termed sequential spatial memory. In addition, this study also found gender differences; females drew more landmarks while males drew more paths. This study has only uncovered the beginning of the sequence puzzle. A larger sample population, cross-disciplinary work and investigation on links between sketch map sequence and memory are required to further our understanding of peoplesâ perception of the environment and how that is reflected in the multilayered sketch maps. This understanding can lead to modelling peoplesâ sketch maps followed by predicting travel behaviours
The Role of Geospatial Thinking and Geographic Skills in Effective Problem Solving with GIS: K-16 Education
Effective use of a Geographic Information System (GIS) is hampered by the limited geospatial reasoning abilities of students. The ability to reason with spatial relations, more specifically apply geospatial concepts, including the identification of spatial patterns and spatial associations, is important to geographic problem solving in a GIS context. This dissertation examines the broad influence of three factors on GIS problem solving: 1) affection towards computers, geography, and mathematics, 2) geospatial thinking, as well as 3) geographic skills.
The research was conducted with 104 students in Waterloo, Ontario, Canada. Students were drawn from four educational levels: grade 9 students, 13 to 14 years of age; 1st year undergraduate university students, 3rd and 4th year undergraduate geography majors; and geography students at the graduate level ranging from 22 to 32 years of age. The level of affection is measured with modified scales borrowed from psychology. Results show that students in general exhibit positive sentiments toward computers and geography but less so towards mathematics. Spatial thinking and knowledge of geospatial concepts are measured by a 30-item scale differentiating among spatial thinkers along a novice-expert continuum. Scores on the scale showed an increase in spatial reasoning ability with age, grade, and level of education, such that grade 9 students averaged 7.5 out of 30 while the mean score of graduate students was 20.6.
The final exercise assessed pertinent skills to geography namely inquiry, data collection, and analysis. In general, there was a positive correlation in the scores such that the skill proficiency increased with grade. Related analysis found three factors that affect problem-solving performance with a GIS. These include age, geographic skills (inquiry and analysis), and geospatial thinking (subscales analysis, representation, comprehension, and application). As well, the relationship(s) between performance on the geospatial scale and the observed problem-solving sequences and strategies applied on a GIS was examined. In general, students with lower scores were more apt to use basic visualization (zoom/measure tools) or buffer operations, while those with higher scores used a combination of buffers, intersection, and spatial queries. There were, however, exceptions as some advanced students used strategies that overly complicated the problem while others used visualization tools alone.
The study concludes with a discussion on future research directions, followed by a series of pencil and paper games aimed to develop spatial thinking within a geographic setting
Birch reduction of benzenesulfonamide and benzenephosphonic acid
The use of an alkalai metal dissolved in liquid ammonia and a proton source such as alcohol to affect partial reduction of aromatic compounds, commonly known as the BIrch reduction, has proven to be a synthetic procedure of great utility. (1) The flexibility and usefulness of this reaction has attracted increasing attention in recent times, primarily by BIrch (1,2). The overall reaction occuring during the Birch reduction of benzene is indicated by Figure 1. [see PDF]
Birch has suggested that the reaction may proceed by the transfer of one electron to the aromatic nucleus to give a radical anion or a transfer of two electrons to form a dianion. (2,3,4) Either intermediate would then be a very strong base and would react promptly with proton donors such as alcohols, water, or ammonium salts. Figure 2 [see PDF
Hochgeschwindigkeits-EinschlÀge von Asteroiden, Kometen und Meteoriten
In dieser Arbeit werden physikalische Prozesse von Hoch-GeschwindigkeitseinschlĂ€gen auf planetaren Körpern studiert. Zuerst wird innerhalb einer semi-analytischen NĂ€herung fĂŒr die Hydrodynamik ein kinetisches Modell der GröĂenverteilung von Kondensaten untersucht, unter Verwendung der homogenen Keimbildungstheorie. Als Lösung der kinetischen Gleichungen wird eine multi-modale GröĂenverteilung erhalten, welche bis zu drei Maxima bei verschiedenen GröĂen von Zentimetern bis zu Nanoskalen besitzt. Danach wird die Zustandsgleichung der Gasphase zu einem sehr allgemeinen chemischen Gleichgewicht mit 209 Sorten erweitert; das Kondensat ist eine ideale Lösung. Die Hydrodynamik wird numerisch in sphĂ€rischer Symmetrie behandelt. VorlĂ€ufige Ergebnisse, mit einer GesamthĂ€ufigkeit entsprechend einem primitiven Chondriten als verdampftem Impaktor erhalten, zeigen eine metallreiche Zusammensetzung des Kondensats bei Temperaturen zwischen 3000 und 4000 K. Danach wird ein Volume-of-fluid Multi-Material Hydrodynamik-Algorithmus entwickelt. Eine Godunov-Methode, basierend auf dem HLLC-Löser wird getestet, erweist sich jedoch als zu wenig robust bei allgemeiner Zustandsgleichung. AnschlieĂend wird eine traditionelle Methode weiterentwickelt, welche kĂŒnstliche ViskositĂ€t benutzt. Neue Aspekte im Vergleich mit existierenden Algorithmen sind dabei ein ökonomischer, geometrisch exakter und "overshoot"-freier stĂŒckweise linearer Advektions-Algorithmus,..thesi
Morphological Comparison of Three Asian Native Honey Bees (Apis Cerana, a. Dorsata, a. Florea) in Northern Vietnam and Thailand
Three species of Asian native honey bees (Apis cerana, A. florea and A. dorsata) from northern Vietnam and Thailand were morphologically analyzed for investigations on their geographic variations and relations. In Vietnam, samples were collected from feral and managed colonies. In Thailand, the collections were from feral colonies or from field bees on flowers. Morphological analysis was carried out, using measurements common to honeybee taxonomy. Measured characters were done under stereomicroscope with an ocular micrometer. ANOVA program and multivariate statistical analyses were applied for treating the data. Overall, A. cerana populations in northern Vietnam are significantly morphologically different than from those in Thailand. It may be due to their different geographic locations between the Thai and Vietnamese populations of A. cerana. A. florea bees from Vietnam are generally bigger in size than those from Thailand, but the differences are uncertain. In contrast, the body size of A. dorsata populations from Thailand are bigger than those from Vietnam. However, these differences are also not significant. It is necessary to take further comparative investigations of these bee species from both countries
The transition of small-scale coffee farming systems and new pathways for coffee production: A case study in the central highlands of Vietnam
The dynamics of agriculture in general and coffee farming systems need to be investigated to derive insights for policies and interventions to promote sustainable agriculture. Through a systematic approach, including historical and adaptive ones, the study aims to probe the spatial-temporal transition of coffee farming systems. We found evidence for the diverse adaptive capacity of the coffee farming systems in Dak Lak province in their response to various factors. Moreover, an economic comparison was made between coffee farming systems, including mono-coffee farms and coffee-based intercropped ones. The study showed that coffee-based intercropped farms yield higher returns than mono-cropping ones by productivity enhancement, land equity ratio, and gross margin. These findings provided empirical evidence to design appropriate policies for the sustainable development of coffee farming
Hypervelocity Impact of Asteroids, Comets and Meteorites
In dieser Arbeit werden physikalische Prozesse von Hoch-GeschwindigkeitseinschlĂ€gen auf planetaren Körpern studiert. Zuerst wird innerhalb einer semi-analytischen NĂ€herung fĂŒr die Hydrodynamik ein kinetisches Modell der GröĂenverteilung von Kondensaten untersucht, unter Verwendung der homogenen Keimbildungstheorie. Als Lösung der kinetischen Gleichungen wird eine multi-modale GröĂenverteilung erhalten, welche bis zu drei Maxima bei verschiedenen GröĂen von Zentimetern bis zu Nanoskalen besitzt. Danach wird die Zustandsgleichung der Gasphase zu einem sehr allgemeinen chemischen Gleichgewicht mit 209 Sorten erweitert; das Kondensat ist eine ideale Lösung. Die Hydrodynamik wird numerisch in sphĂ€rischer Symmetrie behandelt. VorlĂ€ufige Ergebnisse, mit einer GesamthĂ€ufigkeit entsprechend einem primitiven Chondriten als verdampftem Impaktor erhalten, zeigen eine metallreiche Zusammensetzung des Kondensats bei Temperaturen zwischen 3000 und 4000 K. Danach wird ein Volume-of-fluid Multi-Material Hydrodynamik-Algorithmus entwickelt. Eine Godunov-Methode, basierend auf dem HLLC-Löser wird getestet, erweist sich jedoch als zu wenig robust bei allgemeiner Zustandsgleichung. AnschlieĂend wird eine traditionelle Methode weiterentwickelt, welche kĂŒnstliche ViskositĂ€t benutzt. Neue Aspekte im Vergleich mit existierenden Algorithmen sind dabei ein ökonomischer, geometrisch exakter und "overshoot"-freier stĂŒckweise linearer Advektions-Algorithmus, kombiniert mit einer Material-Ordnungsstrategie. Weiterhin wird eine kompatible Diskretisierung fĂŒr den Impuls in Zylinderkoordinaten abgeleitet. Damit werden EinschlĂ€ge von Asteroiden in die feste Erdkruste und in den Ozean studiert. Beide Beispiele enthalten GravitationskrĂ€fte und eine hydrostatische Gleichgewichts-Konfiguration als Anfangszustand. SchlieĂlich wird mit Hilfe der Godunov-Methode der Einschlag eines Projektils mit 10 km/s auf einer KometenoberflĂ€che, als Eis beschrieben, simuliert, was dem Szenario der âDeep Impactâ Mission Ă€hnelt.In this work, physical processes during hypervelocity impact on planetary bodies are studied. First, within a semi-analytical approximation for hydrodynamics, a kinetic model for the size distribution of impact condensates is investigated, applying homogeneous nucleation theory. The solution of the kinetic equations results in a multi-modal size distribution, with maxima occurring at up to three different scales spanning a range from centimetres to nanoscale. Subsequently, the gas phase EOS is generalized to a chemical equilibrium of 209 species, the condensate is an ideal solution. Hydrodynamics is treated numerically in spherically symmetric approximation. Preliminary results obtained with the overall composition as a primitive chondrite for the evaporated impactor yield a metal-rich condensate in between 4000 and 3000 K. Next, a volume-of-fluid (VOF) multi-material hydrodynamic algorithm is developed. A Godunov method based on the HLLC Riemann solver is tested, but found to be less robust in the case of complicated EOS. Subsequently, a more traditional method, using artificial viscosity, is developed further. Novel aspects are an economic, geometrically exact and overshoot-free piecewise linear advection algorithm combined with a material ordering strategy and a compatible discretisation for momentum in cylindrical coordinates. Using this method, asteroid impact into the solid crust of the Earth and into the ocean is studied. Both these examples include gravity and use a hydrostatic equilibrium configuration as initial state. Finally, with the Godunov method, the impact of a projectile at 10 km/s on to a comet surface taken as water ice is simulated, resembling the scenario of the âDeep impactâ mission
Geologic Map of the Greater Portland Metropolitan Area and Surrounding Region, Oregon and Washington
This geologic map encompasses the greater Portland metropolitan area (the metro area), an urbanized region astride the confluence of the Willamette and Columbia Rivers in Oregon and Washington. The metro area includes the Portland-VancouverHillsboro metropolitan area, defined by the U.S. Census as the 23rd largest such area in the U.S., having a population of more than 2.2 million people (https://www.census.gov/dataviz/visualizations/026/508.php). The map area extends beyond the urbanized core to include outlying towns and cities and the bounding fault zones that separate the metro area from the adjacent Coast Range and Cascade Range (or Cascades; figs. 1, 2, and 3). The metro area is an area of great scenic, natural, and cultural resources and is the major economic hub of Oregon, containing nearly half of the stateâs population and generating 75 percent of its gross domestic product (http://oregoneconomicanalysis.com)
Visualization and analysis of microarray and gene ontology data with treemaps
BACKGROUND: The increasing complexity of genomic data presents several challenges for biologists. Limited computer monitor views of data complexity and the dynamic nature of data in the midst of discovery increase the challenge of integrating experimental results with information resources. The use of Gene Ontology enables researchers to summarize results of quantitative analyses in this framework, but the limitations of typical browser presentation restrict data access. RESULTS: Here we describe extensions to the treemap design to visualize and query genome data. Treemaps are a space-filling visualization technique for hierarchical structures that show attributes of leaf nodes by size and color-coding. Treemaps enable users to rapidly compare sizes of nodes and sub-trees, and we use Gene Ontology categories, levels of RNA, and other quantitative attributes of DNA microarray experiments as examples. Our implementation of treemaps, Treemap 4.0, allows user-defined filtering to focus on the data of greatest interest, and these queried files can be exported for secondary analyses. Links to model system web pages from Treemap 4.0 enable users access to details about specific genes without leaving the query platform. CONCLUSIONS: Treemaps allow users to view and query the data from an experiment on a single computer monitor screen. Treemap 4.0 can be used to visualize various genome data, and is particularly useful for revealing patterns and details within complex data sets
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