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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.
61

Cálculo das faixas de energia não-relativísticas do arseneto de alumínio

Lima, Ivan Costa da Cunha 15 July 1972 (has links)
Orientador: Nelson de Jesus Parada / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-07-23T17:20:23Z (GMT). No. of bitstreams: 1 Lima_IvanCostadaCunha_M.pdf: 1212472 bytes, checksum: de3745907fbae98ea7745ef76b18de3c (MD5) Previous issue date: 1972 / Resumo: O presente trabalho trata da determinação das faixas eletrônicas do AlAs utilizando-se o método APW-k.p o ( não relativístico ). Foi usado o valor a= 5.660 Å para o parâmetro de rede eV= -0,7500 ua para o potencial constante fora das esferas na aproximação "muffin-tin". Foram obtidos sate ( 7 ) níveis de energia no ponto G - centro da zona de Brillouin - sendo três ( 3 ) triplamente degenerados ( simetria G 15 ), um ( 1 ) duplamente degenerado ( simetria G12 ) e três ( 3 ) não degenerados ( simetria Gl ). O valor do "gap" direto obtido foi E'g = 1,58 eV, entre os níveis G15v e Glc. Com as funções de onda e os níveis de energia no ponto G, foram calculados os elementos de matriz do momento a serem utilizados na expansão k.p, para obtermos as faixas nos eixos de simetria 2p/a ( 1,0,0 ), 3p/2a( 1,1,0 ) e p/a ( 1,1,1 ). O "gap" indireto foi encontrado no primeiro eixo - ( eixo D ) - próximo do ponto X, com valor Eg = 1,36 eV. Os resultados obtidos mostraram ser qualitativamente satisfatórios quando comparados com os encontrados na literatura, indicando, entretanto, serem necessárias correções relativísticas e de interação spin-orbita / Abstract: Not informed. / Mestrado / Física / Mestre em Física
62

Estudo de níveis profundos em GaAs usando DLTS

Tabata, Americo Sheitiro 25 July 1988 (has links)
Orientador: Marcio A.A. Pudensi / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-07-17T14:01:56Z (GMT). No. of bitstreams: 1 Tabata_AmericoSheitiro_M.pdf: 727451 bytes, checksum: 6f553ad446b36fbefaabb37c21ce3d4a (MD5) Previous issue date: 1988 / Resumo: Não informado / Abstract: Not informed. / Mestrado / Física / Mestre em Física
63

THE ROLE OF CONNEXIN-43-MEDIATED GAP JUNCTION INTERCELLULAR COMMUNICATION IN BLOOD FORMATION

KASTL, BRYAN DARYL 13 July 2006 (has links)
No description available.
64

CLOSING THE OPPORTUNITY GAP IN AFFLUENT SUBURBAN SCHOOLS: WHAT SEEMS TO BE MISSING IN THE LAND OF OPPORTUNITY?

Brown, Brandon January 2020 (has links)
There is a gap in achievement between African American/Black and Latinx students and their White counterparts. An abundance of researchers has concluded that it is a result of a gap in opportunities of access. Some researchers have shifted the conversation from achievement gap to opportunity gap. In the discussion and creation around school policies used to address the opportunity gap that exist in affluent suburban school districts, the exchange between school and student cultures seldom receive attention because they are hard to measure, and interventions that may stem from their results are not necessarily generalizable (Carter, 2013). This study attempts to unveil the perceptions that Black and Latinx students who attend predominately White affluent suburban schools have regarding access to tangible and intangible resources and opportunities. Through the lens of students, insight into the feelings, beliefs, and identity, of Black and Latinx students toward education and the disparities of academic achievement in predominately White affluent suburban schools will be highlighted. / Educational Leadership
65

Breaking Down Barriers Through the "STEAM" College Success Program: Increasing STEM Bachelor's Degrees for First-Generation Hispanic Students of the Desert Southwest

January 2019 (has links)
abstract: ABSTRACT To remain competitive on local, state, and national levels and to achieve future economic and social goals, Imperial and Yuma County need an educated workforce. The primary industries supporting the desert region are technical, science, technology, enginnering and mathematics (STEM)-based, and require a highly skilled and educated workforce. There continue to be vast disparities in terms of numbers of students declared and enrolled in STEM transfer degree programs and the number of students completing STEM bachelor’s degrees. Perceptions regarding post-secondary education start to develop at a young age and can prevent or enable a student’s development of post-secondary aspirations. Understanding a student’s perceptions of barriers are important because they can prevent students from completing a four-year degree. The pilot research provided in the study are the first steps in helping educators and community leaders understand what drives and form student perceived educational barriers and student perceptions of self, and then provide a better understanding of first-generation Hispanic students’ value of higher education. As part of the study, I designed the science, technology, engineering, agriculture and mathematics (“STEAM”) College Success Program to help college students overcome the perceived barriers intervening with the completion of a bachelor’s degree. The program involved community, industry, and college students in a unique experience of incorporating a one-week camp, academic year of mentorship, STEM education, and college support. Pilot results of the “STEAM” College Success Program indicate the innovation was effective in reducing perceived barriers relating to college success and bachelor’s degree completion.and was most effective in the area of self-efficacy and personal achievement. / Dissertation/Thesis / Doctoral Dissertation Educational Leadership and Policy Studies 2019
66

Identifying Knowledge Gaps Using a Graph-based Knowledge Representation

Schmidt, Daniel P. 21 May 2020 (has links)
No description available.
67

Safety and Operational Assessment of Gap Acceptance Through Large-Scale Field Evaluation

Tupper, Steven Maxwell 01 January 2011 (has links) (PDF)
Given that “driver error” is cited as a contributing factor in 93 percent of all crashes, understanding driver behavior is an essential element in mitigating the crash problem. Among the more dangerous roadway elements are unsignalized intersections where drivers’ gap acceptance behavior is strongly correlated to the operational and safety performance of the intersection. While a basic understanding of drivers’ gap acceptance behavior exists, several unanswered questions remain. Previous work has attempted to address some of these questions, however to date the research has been somewhat limited in scope and scale due to the challenges of collecting high fidelity gap acceptance data in the field. This research initiative utilized software newly developed for this project to collect gap acceptance data on 2,767 drivers at 60 sites, totaling 10,419 driver decisions and 22,639 gaps in traffic. This large-scale data collection effort allowed many of these remaining questions to be answered with an improved degree of certainty. This research initiative showed that naturalistic driver gap acceptance behavior can realistically be observed and accurately recorded in the field in real time using a newly developed software tool. This software tool and study methodology was validation using high fidelity video reduction techniques. This research compared different methods of analyzing gap acceptance data, in particular determining critical gap, seeing that the method used significantly affects the results. Conclusions were draw about the merits of each of the ten analysis methods considered. Through the analysis of the large data set collected, the research determined that there exist appreciable and identifiable differences in gap acceptance behavior across drivers under varied conditions. The greatest differences were seen in relationship to wait time and queue presence. If a driver has queued vehicles waiting behind them and/or has been waiting to turn for a long period of time, they will be more likely to accept a smaller gap in traffic. Additionally, an analysis of gap acceptance as it relates to crash experience identified critical situations where a driver's gap acceptance behavior contributes to the occurrence of a crash. Characteristics of the driver such as gender and approximate age associated with specific crashes were examined. Teen drivers were identified as exhibiting aggressive gap acceptance behavior and were found to be overrepresented in gap acceptance related crashes. Ultimately, a better understanding of the driver and environmental factors that significantly contribute to increased crash risk will help guide the way to targeted design solutions.
68

The Cost of Higher Education: Impacts of Student Loan Debt on the Life Course for Hispanic Americans

Knudsen, Jennifer L 08 1900 (has links)
Student loan debt continues to be an issue in the U.S., with potential long-term effects on loan repayment and potential wealth accumulation. In particular, minorities face barriers in the educational system and accruing wealth. Hispanics occupy a middling position in the U.S. racial hierarchy. Using the National Longitudinal Survey of Youth 1997 geocode data, in this study I examined how Hispanic-White differences in student debt change over time and how student debt influences wealth. In addition, I accounted for immigration status via parents' nativity status to investigate debt burdens and subsequent wealth for these respondents. I used hierarchical linear growth models to examine debt growth over time and linear decomposition to examine Hispanic-White differences in wealth accumulation and the impact of student debt on these differences. While findings were largely statistically insignificant, I found that Hispanics tended to start with less debt than their White counterparts and that student debt initially grew for both groups. However, White respondents pay off their debt more quickly than Hispanics. In addition, I found that the wealth gap between White and Hispanic respondents grew significantly between the ages of 20 and 35. While Hispanics tended to start with less debt, my findings suggest that student debt still plays a role in Hispanics' financial well-being, including Hispanic wealth development and the perpetuation of the Hispanic-White wealth gap.
69

Experimental investigation of the thermo-mechanical response of Intumescent Mat Material

Kim, Hyungjun January 2000 (has links)
No description available.
70

Strategier för att reducera förväntningsgapet : Hur går revisorn, revisionsbyrån och professionen tillväga?

Suomela, Johan, Eliacik, Serhat, Persson, Robin January 2006 (has links)
<p>The expectation gap is the definition of the differences between what the interests expects from the auditor and what the auditor delivers. A number of studies have been done regarding the expectation gap and generally they point at the existence of an expectation gap.</p><p>In our paper we want to discover and see how strategies are used in the process to reduce the expectation gap from three levels. The levels we treat are auditors, audit bureaus and the profession. We have chosen to examine the strategies used by the three levels to reduce the expectation gap to following interest groups, owners, management/board of directors, and creditors.The purpose with our paper is to create understanding about how auditors, audit bureaus and the profession use strategies in the process to reduce the expectation gap.</p><p>With existing theories as ground we have construed and developed our own theory about which thinkable strategies the three levels can use.</p><p>We have interviewed auditors, representatives from bureaus and a spokesman for the profession. In the examination we have used telephone interviews with questions based on our operationalization. From our analyse we came to following conclusion: All three levels use strategies in the process to reduce the expectation gap, but not to all interests and not in the same range. We can se a common denominator for the strategies that are used by the levels, they are built on communication. The difference between them is that they take way thru different communication channels. Examples of communication channels are commission letters and oral communication.</p> / <p>Förväntningsgapet är definitionen på skillnaden mellan vad intressenterna förväntar sig av revisorn och vad revisorn i själva verket tillhandahåller. Det har utförts en rad studier gällande förväntningsgapet och generellt pekar de på existensen av ett förväntningsgap.</p><p>Vi vill i vår uppsats upptäcka och se hur strategier används i arbetet mot att reducera förväntningsgapet utifrån tre nivåer. Nivåerna vi behandlar är revisorer, revisionsbyråer och professionen. Vi har valt att undersöka de tre nivåernas strategier för att reducera gapet till följande tre intressentgrupper, ägare, kreditgivare och ledning/styrelse.</p><p>Syftet med vår uppsats är att skapa förståelse för hur revisorn, revisionsbyrån och professionen använder sig av strategier för att reducera förväntningsgapet till intressenterna.</p><p>Med existerande teorier som grund har vi tolkat och utvecklat en egen teori för vilka tänkbara strategier som kan användas av de tre nivåerna.</p><p>Vi har intervjuat revisorer, representanter från byråer och en talesman för professionen. Vi har i undersökningen använt oss av telefonintervjuer med frågor baserade på vår operationalisering. Utifrån vår analys kom vi fram till följande: alla tre nivåer använder sig av strategier för att reducera förväntningsgapet, men inte till alla intressenter och inte i lika stor omfattning. Vi kan se en gemensam nämnare för strategierna som idag används av de tre nivåerna, nämligen att de bygger på kommunikation. Skillnaden mellan de är att de sker via olika kommunikationskanaler. Exempel på kommunikationskanaler är uppdragsbrev och muntlig kommunikation.</p>

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