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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Using Combined Integration Algorithms for Real-time Simulation of Continuous Systems

Harbor, Larry Keith 01 January 1988 (has links) (PDF)
At many American colleges and universities, efforts to enhance the retention of a diverse group of students have become a priority. This study represents part of this effort at the University of Central Florida, a large public suburban state university in the South. Specifically, this investigation evaluated Pegasus '95 and the Academic Mentoring Program offered in the Summer and Fall Semesters of 1995 to specially-admitted students who fell short of regular admissions requirements. During the summer, Pegasus '95 provided testing, orientation, guided course work, study skills workshops, and mentoring, both individually and in the context of cohesive socialization groups of approximately 15 students each. In the Fall 1995 Semester, students were highly encouraged to participate in one-on-one mentoring in the Academic Mentoring Program (AMP) available through the Student Academic Resource Center (SARC), a university-based office which provides a variety of academic assistance services. A multiple regression analysis was conducted using the following independent predictor variables: gender, SAT/ACT scores, Pegasus participation, use of the AMP in the Fall 1995 semester, four summary scores from the College Student Inventory (CSI), and eight scaled scores from the Noncognitive Questionnaire (NCQ). Dependent variables were individual student GPA in the Summer and Fall 1995 semesters, cumulative GPA after two semesters, and enrolled credit hours into the Spring 1996 academic term. Overall, it was expected that a combination of predictor variables, including both traditional cognitive factors (SAT/ACT scores and high school GPA) and noncognitive factors (NCQ scores and CSI scores, Pegasus participation, and mentoring by the SARC) would significantly predict GP A and retention. The study found that a regression equation including gender, high school GPA, overall SAT scores and the eight NCQ scale scores significantly predicted Fall 1995 and cumulative GPA after two semesters but not Summer 1995 GPA or credit hours enrolled in Spring 1996. Attendance at Pegasus meetings was also shown to be significantly and positively associated with Fall 1995 GPA and cumulative GPA after two semesters but not of Summer 1995 GPA or credit hours enrolled in Spring 1996. Gender, high school GP A, the ACT score and the CSI Dropout Proneness scale significantly predicted credit hours enrolled in Spring 1996, as did use of the AMP program provided by the SARC. Of particular interest was the finding that including noncognitive factors in significant equations led to a greater explanation of the variance than could be obtained with any of the traditional cognitive measurements alone, suggesting that with academically disadvantaged students noncognitive measures must be considered in predicting who can succeed and persist in college.
2

Uplift Modeling : Identifying Optimal Treatment Group Allocation and Whom to Contact to Maximize Return on Investment

Karlsson, Henrik January 2019 (has links)
This report investigates the possibilities to model the causal effect of treatment within the insurance domain to increase return on investment of sales through telemarketing. In order to capture the causal effect, two or more subgroups are required where one group receives control treatment. Two different uplift models model the causal effect of treatment, Class Transformation Method, and Modeling Uplift Directly with Random Forests. Both methods are evaluated by the Qini curve and the Qini coefficient. To model the causal effect of treatment, the comparison with a control group is a necessity. The report attempts to find the optimal treatment group allocation in order to maximize the precision in the difference between the treatment group and the control group. Further, the report provides a rule of thumb that ensure that the control group is of sufficient size to be able to model the causal effect. If has provided the data material used to model uplift and it consists of approximately 630000 customer interactions and 60 features. The total uplift in the data set, the difference in purchase rate between the treatment group and control group, is approximately 3%. Uplift by random forest with a Euclidean distance splitting criterion that tries to maximize the distributional divergence between treatment group and control group performs best, which captures 15% of the theoretical best model. The same model manages to capture 77% of the total amount of purchases in the treatment group by only giving treatment to half of the treatment group. With the purchase rates in the data set, the optimal treatment group allocation is approximately 58%-70%, but the study could be performed with as much as approximately 97%treatment group allocation.
3

Improving information perception from digital images for users with dichromatic color vision

Shayeghpour, Omid January 2013 (has links)
Color vision deficiency (CVD) is the inability or limited ability to recognize colors and discriminate between them. A person with this condition perceives a narrower range of colors compared to a person with a normal color vision. A growing number of researchers are striving to improve the quality of life for CVD patients. Finding cure, making rectification equipment, providing simulation tools and applying color transformation methods are among the efforts being made by researchers in this field. In this study we concentrate on recoloring digital images in such a way that users with CVD, especially dichromats, perceive more details from the recolored images compared to the original image. The main focus is to give the CVD user a chance to find information within the picture which they could not perceive before. However, this transformed image might look strange or unnatural to users with normal color vision. During this color transformation process, the goal is to keep the overall contrast of the image constant while adjusting the colors that might cause confusion for the CVD user. First, each pixel in the RGB-image is converted to HSV color space in order to be able to control hue, saturation and intensity for each pixel and then safe and problematic hue ranges need to be found. The method for recognizing these ranges was inspired by a condition called “unilateral dichromacy” in which the patient has normal color vision in one eye and dichromacy in another. A special grid-like color card is designed, having constant saturation and intensity over the entire image, while the hue smoothly changes from one block to another to cover the entire hue range. The next step is to simulate the way this color card is perceived by a dichromatic user and finally to find the colors that are perceived identically from two images and the ones that differ too much. This part makes our method highly customizable and we can apply it to other types of CVD, even personalize it for the color vision of a specific observer. The resulting problematic colors need to be dealt with by shifting the hue or saturation based on some pre-defined rules. The results for the method have been evaluated both objectively and subjectively. First, we simulated a set of images as they would be perceived by a dichromat and compared them with simulated view of our transformed images. The results clearly show that our recolored images can eliminate a lot of confusion from user and convey more details. Moreover, an online questionnaire was created and 39 users with CVD confirmed that the transformed images allow them to perceive more information compared to the original images.
4

現行都市更新條例中協議合建之定位與相關法律問題研究 / A study on the Characterization of Joint Construction Agreement and Relevant Legal Problems within Urban Renewal Act

張芳清, Chang, Fang Chin Unknown Date (has links)
本文以研究採「協議合建」方式進行都市更新之初衷,試圖從本土傳統合建制度之演進歷程為本,復以引進日本都市再開發法中權利變換制度而制定之我國都市更新條例,根據其立法主軸之「權利變換」制度為綱,經由比較分析與歸納,嘗試建置出我國都市更新條例中「協議合建」應有之法制規範及應注意事項。 本於協議合建方式下進行都市更新,在斟酌當事人真意及都市更新之目的下,本文將所簽訂之合建契約定性為「承攬與互易之混合契約」,作為法律關係分析之依據。文中,並對權利變換之多階段行政程序,詳加論述與研究,可做為瞭解都市更新條例立法主軸之認識與發現爭議之所在。 針對協議合建具有全體權利人同意之最重要特徵,本文引據公寓大廈管理條例中關於重建之規範,與新北市率全國之冠,於民國102年所推出之「簡易都更」政策加以研究比較,從而得以回饋至協議合建,更加認清其本質上具有之特質。 最後本文強調,協議合建具有濃厚的私法自治特徵,本身只是一個都市更新可據以採用的可行方式,並無法直接對其做出評價;而是都市更新條例中之立法制度,允許私人基於較偏私益之目的下,於劃定更新地區外自行劃設更新單元申請實施更新事業,從而造就協議合建雙面刃之性格。是以,在規範協議合建時,當制度面向不同時,可能導致效果扭轉之認知,這是我國協議合建制度所面臨之最大挑戰。 結論中,為確立協議合建於都更條例中應有之定位,將本質上屬重要之事項,以修法建議加以確立。惟政策立法論非在本文主題所強調之列,其他影響協議合建之法條規範,當可從法解釋論與司法救濟上尋求解決之道。 / This thesis is based on the concept of traditional joint construction in Taiwan and "the rights transformation" which is the main idea of Urban Renewal Act in Taiwan transplanted from Urban Redevelopment Act in Japan to study on the "joint construction agreement" in Urban Renewal Act in Taiwan. By comparison and generalization, try to find the instructions for legislation of "joint construction agreement" in Urban Renewal Act in Taiwan. Based on the urban renewal using the method of joint construction agreement, the intent of the parties and the purpose of urban renewal, the contracts of joint construction mentioned in the thesis are identified as the mixed contract of exchanging and contracting to analyze the legal relationships. Besides, discussing the multi-leveled administrative procedure of rights transformation could help us find the issue of Urban Renewal Act. By researching on the regulation of reconstruction in Condominium Administration Act Building Administration Division and the policy of "Simple Urban Renewal" that New Taipei City government has promoted since 2013, we could clarify the character of the agreement among right holders of joint construction agreement. Joint construction agreement having the character of autonomy of private law is one method to urban renewal so it is hard to value it directly. Because of the legislation of Urban Renewal Act allowing people to designate renewal unit besides the designation of the renewal area for personal interests, the joint construction agreement becomes a double-edged sword. Therefore, the challenge of joint construction in Taiwan is the effects will differ from the purposes of joint construction agreement. In conclusion, the important things of joint construction agreement should be mentioned in the legislation amendment proposals to clarify the joint construction agreement in Urban Renewal Act. However, the policy of legislation is not emphasized in the thesis. Problems of other regulations affecting the joint construction agreement could be solved by the interpretation of law and judicial relief.
5

Evolutionäre Sprachtransformation: Ereignismodell und Rekonstruktionsverfahren für Sprachwandel

Jung, Hagen 06 June 2011 (has links)
Verwandte Sprachen besitzen Wörter gleichen Ursprungs. Im Laufe der Geschichte ändern diese Wörter ihre Gestalt und lassen sich heute in ähnlicher Form in verschiedenen Sprachen als Kognate wiederfinden. In dieser Arbeit wird ein formales Modell zur Beschreibung dieser Änderungen mit Hilfe von kodierten, lexikalischen Wortlisten entwickelt. Das Modell ist geeignet, automatisch und objektiv die Evolution idealisierter Sprachen mit Hilfe eines Sprach-Phylogeniebaumes abzubilden. Dabei werden die einzelnen Buchstabenveränderungen verwandter Wörter und die rekonstruierten Protoformen untersucht. Insbesondere interessieren solche Buchstabenveränderungen, die für mehrere Wörter einer Sprache synchron stattgefunden haben. Ein weiterer Bestandteil des evolutionären Modells ist die Identifikation von Kognaten, um die möglichen Buchstabenersetzungen zwischen den verwandten Wörtern untersuchen zu können. Für die Rekonstruktion linguistisch plausibler Buchstabenveränderungen und Kognatzuweisungen entlang einer Sprachphylogenie wird ein parsimonisches Kostenmodell verwendet, welches die verschiedenen Sprach- und Transformationsverläufe bewertet. Die Suche nach der plausibelsten Lösung ist NP-vollständig, so dass für den enorm großen Suchraum ein Annäherungsverfahren vorgeschlagen wird. Ausgehend von einer geeigneten Rekonstruktion wird durch sukzessives und minimales Verändern einzelner Transformationen oder Kognatzuweisungen mit Hilfe eines speziell entwickelten Approximationsverfahrens nicht nur eine lokal maximale Lösung, sondern eine global beste Lösung angenähert. Mit dem gewählten umfassenden Ansatz des untersuchten Rekonstruktionsmodells ist eine Sprachentwicklung für kleine Wortlisten in angemessener Zeit berechenbar. Als großer Vorteil ist die Nachvollziehbarkeit aller Einzeltransformationen für den linguistischen Diskurs anzusehen. Insbesonders die Identifikation regulärer Buchstabenersetzungen mit möglicher Interpretation als Lautwandel früherer Sprachen ist hierbei von Bedeutung. / Related languages contain words of the same origin. Through time these words change. Remaining similarities between these words can be detected in different languages. In this work, transformations across lexical wordlist are used to model these changes. To reconstruct the possible pathways of language change an algorithm is choosen that calculates the phylogeny, the appropriate protolanguage and the cognate sets. An evaluation function detects plausible evolutions. Because of the enormous amount of possible solutions an approximative method is proposed that continuously modifies and improves possible solutions.
6

Georeferering för 3D-visualisering av Sveriges historiska kartor med Open Source och öppna data : En undersökning av samtida möjligheter och begränsningar / Georeferencing for 3D-visualisation of historical maps of Sweden using open source and open data : A study of current possibilities and limitations

Hermansson, Johan January 2024 (has links)
Den första detaljerade topografiska karteringen som täcker en större del av Sverige är den s.k. Häradskartan som framställdes under 1800-talets andra hälft och som följdes av Generalstabens topografiska karta under början av 1900-talet. För framställning av kartorna upprättades först stomkartor genom transporter av äldre kartor i större skala från skiften och lantmäteriförrättningar. Historiska topografiska kartor ur Häradskartan och stomkartorna till Generalstabens topografiska karta publicerades under 2023 av Naturvårdsverket i form av digitala kartraster som georefererats med en automatisk metod baserad på rutnät av kartbladshörn för kartserierna. Denna studie syftar till att undersöka huruvida resultatet av den automatiska georefering som utförts med kartbladshörnen kan förbättras med en metod baserad på identifiering av gemensamma passpunkter mellan de historiska kartan och den moderna topografiska karta som finns tillgänglig som öppen data från Lantmäteriet. För att den metod som används ska vara användbar för en intresserad allmänhet undersöktes de möjligheter för georeferering av de historiska topografiska kartorna som finns med kostnadsfria Open Source-programvaror och öppna data. För att resultatet av georefereringen ska kunna utvärderas i en praktisk tillämpning undersöktes skapande av 3D-visualiseringar av de historiska kartorna. Studien avgränsas till ett område omfattande 400 000 ha huvudsakligen i Örebro län och de georefereringsmetoder som finns i programvaran QGIS. Passpunkter identifierades i den moderna topografiska kartan där byggnadspunkter för slott, kyrkor och herrgårdar som kunde verifieras genom sökningar i bebyggelseregister kompletterades med gränspunkter, vägkorsningar och hydrografiska objekt som visuellt kan antas sammanfalla vid studie av geometrier i de automatiskt georefererade kartorna. För att de kartblad som bygger upp kartserierna ska passa ihop över skarvarna efter georeferering mosaikerades dessa kartblad till ett gemensamt virtuellt kartraster. Resultaten av georefereringen visade att de medelavvikelser som uppmättes i de automatiskt rektifierade kartorna, ca 50 m för Häradskartan och ca 150 m för stomkartorna, kunde förbättras till ca 30 m för båda kartmaterialen med ca sex passpunkter/kvadratmil. Det framgår dock att stora lokala variationer i storleken på felen finns såväl före som efter transformationerna och studien visar på att en mer komplex lokal transformationsmetod med en stor mängd passpunkter fördelade över kartan behövs för att erhålla generella förbättringar av passningen. De skapade 3D-visualiseringarna visade på att en visuellt bättre passning ändå kunde erhållas även med de relativt få passpunkter som använts här. / The first detailed topographic mapping of larger parts of Sweden is the so-called District Economic Map that was produced during the second half of the 19th century and which was followed by the General Staff Map in the beginning of the 20th century. These maps were produced from skeleton maps that were constructed from transports of older large-scaled maps from legal shifts and parcel acts. Historical topographic maps from the District Economic Map and the skeleton maps for the General Staff Map were published in 2023 as digital raster maps that has been georeferenced using an automatic method based on a grid of corner coordinates for the map series. This study aims to investigate whether the result of the automatic georeferencing method can be improved using a method of identifying common ground control points between the historical maps and the modern topographic maps that are available as open data from the Swedish Land Survey. In order for the applied methods to be available to an interested general public this study investigates the possibilities of performing the georeferencing using free open-source software and open data. To allow the evaluation of the georeferencing results in a practical application the historical maps are visualized in 3D. The study is limited to an area encompassing 400 000 ha mainly in Örebro county and the georeferencing algorithms that are available in the QGIS software. Ground control points were identified in the modern topographic map by supplementing building points representing castles, churches and manor houses that can be verified by researching registries of built heritage with boundary points, road crossings and hydrographic objects that visually appear to coincide when studying the geometries of the automatically georeferenced maps. In order to ensure that the map sheets that make up the map series fit over the sheet edges the sheets were mosaicked in a single virtual raster. The results of the georeferencing process show that the mean deviations that could be measured in the automatically referenced maps (approx. 50 m for the District Economic Map and approx. 150 m for the skeleton maps) could be improved to approx. 30 m in both cases using about six control points per 10 000 ha. Large variations in the sizes of local errors are prevalent both before and after the transformations and the study shows that a more complex local transformation method using a large amount of control points is required in order to achieve a general improvement of the fit with modern data. Visualizing in 3D did show, however, that a visually significant improvement could be achieved already using relatively few control points as in this study.
7

Mathematical modelling of virus RSV: qualitative properties, numerical solutions and validation for the case of the region of Valencia

Arenas Tawil, Abraham José 24 May 2010 (has links)
El objetivo de esta memoria se centra en primer lugar en la modelización del comportamiento de enfermedades estacionales mediante sistemas de ecuaciones diferenciales y en el estudio de las propiedades dinámicas tales como positividad, periocidad, estabilidad de las soluciones analíticas y la construcción de esquemas numéricos para las aproximaciones de las soluciones numéricas de sistemas de ecuaciones diferenciales de primer orden no lineales, los cuales modelan el comportamiento de enfermedades infecciosas estacionales tales como la transmisión del virus Respiratory Syncytial Virus (RSV). Se generalizan dos modelos matemáticos de enfermedades estacionales y se demuestran que tiene soluciones periódicas usando un Teorema de Coincidencia de Jean Mawhin. Para corroborar los resultados analíticos, se desarrollan esquemas numéricos usando las técnicas de diferencias finitas no estándar desarrolladas por Ronald Michens y el método de la transformada diferencial, los cuales permiten reproducir el comportamiento dinámico de las soluciones analíticas, tales como positividad y periocidad. Finalmente, las simulaciones numéricas se realizan usando los esquemas implementados y parámetros deducidos de datos clínicos De La Región de Valencia de personas infectadas con el virus RSV. Se confrontan con las que arrojan los métodos de Euler, Runge Kutta y la rutina de ODE45 de Matlab, verificándose mejores aproximaciones para tamaños de paso mayor a los que usan normalmente estos esquemas tradicionales. / Arenas Tawil, AJ. (2009). Mathematical modelling of virus RSV: qualitative properties, numerical solutions and validation for the case of the region of Valencia [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/8316

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