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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.

Studies of defects in composites and an evaluation of thermal expansion moulding

Richards, J. M. January 1986 (has links)
No description available.

The Rooney Rule: Affirmative Action Policy and Institutional Discrimination in the National Football League

Smith, Erica R. 23 December 2008 (has links)
African American underrepresentation in positions of power within the intercollegiate and professional sports hierarchy continues to be a major concern among the media, professional sports organizations, and academic researchers. Although African Americans dominate the rosters of college and professional football teams, they remain grossly underrepresented in the management ranks. In 2002, the NFL designed a diversity plan that is commonly referred to as the "Rooney Rule" in order to increase the recruitment of African-Americans in head coaching positions. This dissertation is based on an examination of the impact of this policy in fostering diversity in NFL hiring patterns for the pre- and post- Rooney Rule eras. The study's objectives were (1) to examine the effectiveness of the Rooney Rule in increasing the hiring of African-American head coaches and (2) to identify and describe the factors and mechanisms that function to either enhance or impede mobility for minority candidates. To achieve these aims data was compiled from a variety of archival sources, including NFL and news media records. Furthermore, an integrative theoretical model was developed to assess the previously overlooked factors, particularly job authority, affecting mobility for minorities. The results revealed that the Rooney Rule has been effective in increasing the number of African-American coaches interviewed and ultimately hired as NFL head coaches. However, it was also found that there are more factors that impede rather than enhance mobility opportunities within the management ranks of the NFL. The integrative theoretical model predicted that race would play a role in a candidate receiving consideration for and being hired for a high authority, high power job. It was concluded that the factor that predicts mobility the most, as assessed by hiring, is authority level; which is the area in which African-Americans are underrepresented, thus leading to decreased chances of being interviewed or hired. Analyses indicated that African-American coaches are found in the less powerful coaching positions, are offered fewer interviews, and are hired less frequently; providing support for the argument that race continues to be important in the connection between leadership and selection for management positions.

Signature Code Design for Offset Stacking Complementary Code CDMA Systems

Lin, Meng-chieh 12 August 2004 (has links)
In this thesis, a new spreading code -- complete offset-stacked spreading code (OSC) is designed and discussed. OSC has a orthogonal complementary property of auto-correlation and cross-correlation. According to the interference-free windows of cross-correlation (CC_IFW) of OSC, the proposed CDMA architecture can offer an MAI-free operation in both down-link (synchronous channel) and up-link (asynchronous channel) transmission under the AWGN channel. According to the interference-free windows of auto-correlation (AC_IFW) of OSC, the proposed CDMA architecture can also offer a part of MI-free operation in both downlink (synchronous channel) and uplink (asynchronous channel). Furthermore, the range of AC_IFW is restricted by the number of offset chips.

Low Leakage Asymmetric Stacked Sram Cell

Ahrabi, Nina 05 1900 (has links)
Memory is an important part of any digital processing system. On-chip SRAM can be found in various levels of the memory hierarchy in a processor and occupies a considerable area of the chip. Leakage is one of the challenges which shrinking of technology has introduced and the leakage of SRAM constitutes a substantial part of the total leakage power of the chip due to its large area and the fact that many of the cells are idle without any access. In this thesis, we introduce asymmetric SRAM cells using stacked transistors which reduce the leakage up to 26% while increasing the delay of the cell by only 1.2% while reducing the read noise margin of the cell by only 15.7%. We also investigate an asymmetric cell configuration in which increases the delay by 33% while reduces the leakage up to 30% and reducing the read noise margin by only 1.2% compared to a regular SRAM cell.

The contrast of planar defects

Chen, Charn-Ying January 1994 (has links)
No description available.

An integration architecture to support error recovery in a multi-robot environment

Philip, Gary P. January 1996 (has links)
No description available.

Modeling generalized stacking fault in Au using tight-binding potential combined with a simulated annealing method

Cai, Jun, Wang, Jian-Sheng 01 1900 (has links)
Tight-binding potential combined with a simulated annealing method is used to study the generalized stacking fault structure and energy of gold. The potential is chosen to fit band structures and total energies from a set of first-principles calculations (Phys. Rev. B54, 4519 (1996)). It is found that the relaxed stacking fault energy (SFE) and anti-SFE are equal to 46 and 102 mJ/m², respectively, and in good agreement with the first principles calculations and experiment. In addition, the potential predicts that the c/a of hcp-like stacking fault structure in Au is slightly smaller than the ideal one. / Singapore-MIT Alliance (SMA)

A study of selenization process of Cu2ZnSnSe4 films

Li, Jhen-yi 26 August 2012 (has links)
Making CZTSe thin film of sputtering and Selenization.Sputtering Zn¡BSn precursor layers on Soda-lime glass¡Aand using evaporating to stack Cu layer.Let it annearing under Selenium atmosphere for less then one hour. We are looking forward a profit annealing process to grow CZTSe thin film.By changing temperature of Substrate¡Bannealing time and heating rate of Substrate. Using XRD and Raman to analysis composition and crystal structure. The morphology from SEM images.Taking analysis on optical and electronic property of the thin film.

Algorithms and Automated Material Handling Systems Design for Stacking 3D Irregular Stone Pieces

Ko, Ming-Cheng 2010 August 1900 (has links)
The motive of this research is to develop a good stacking method with an automatic material handling system and the procedures that can increase productivity, reduce production costs, and prevent labor injury. A diversity of products leads to a number of different kinds of stacking problems. Much research has been done focusing on two-dimensional arrangement for rectangles, circles or irregular shapes, and threedimensional regular-shaped objects such as rectangular boxes. To solve stacking problems, many algorithms such as the genetic algorithm, simulated annealing and other heuristic algorithms have been proposed. The three-dimensional stacking problem has a practical application in the transportation, manufacturing, and construction industries. There has been relatively little emphasis on three-dimensional irregular objects; however, stacking three-dimensional irregular objects has become more common in industry. In this thesis research, three heuristic algorithms are proposed to stack irregular stone pieces nested in a container with multiple layers. Primary functions of the heuristic algorithms include three major parts. First, it approximates irregular shapes to a cluster of straight lines. Secondly, it arranges the approximated angles one-by-one with the proposed step-by-step rule. Finally, it considers the weight of the stone pieces from the pixel calculation for reasons of stability. The first and second algorithms are based on the area and angle of the stone piece and the third one is based on the approximated weight of the stone. An automatic real-time stacking system including pneumatic devices, sensors, relays, a conveyor, a programmable logic controller, a robotic arm, and a vision system was developed for this study. The algorithms developed were tested by this automatic stacking system for better utilization. Three performance measures were presented in the experimental result. Comparisons between the results from three proposed algorithms and that from the bottom-back-left algorithm are made. Experimental data demonstrate that the utilizations and the stabilities of the three proposed algorithms are statistically better than that of the bottom-back-left algorithm. However, the cycle times of the three proposed algorithms have no statistical difference from that of the bottom-back-left algorithm. In addition, a statistical test between each proposed algorithm is also conducted. Both the utilizations and stabilities have statistical differences between each proposed algorithm while the cycle times do not. The results of this study show that the algorithm developed works effectively for solving the stone-pieces stacking problem.

Avaliação da eficácia da técnica de Breath Stacking em mulheres obesas mórbidas quanto à distribuição da ventilação regional na caixa torácica

de Melo Barcelar, Jacqueline 31 January 2011 (has links)
Made available in DSpace on 2014-06-12T23:13:04Z (GMT). No. of bitstreams: 2 arquivo3128_1.pdf: 2153629 bytes, checksum: d621ae51708e16ae35bf5fa5a8be37d6 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2011 / Objetivos: Conhecer o padrão de distribuição da ventilação na caixa torácica em mulheres com diferentes padrões de obesidade, e avaliar a eficácia da técnica de Breath Stacking (BS) em mulheres com obesidade mórbida. Métodos: O estudo foi realizado em duas etapas. A primeira foi um estudo transversal com 32 mulheres obesas (IMC≥40kg/m2) e 29 mulheres com peso normal (IMC=18,5 - 24,9 kg/m2) na faixa etária entre 19 e 60 anos , dividida em grupos de acordo com a relação cintura/quadril (RCQ) em GOC-obesidade central (RCQ>0.85),n=21, GOP-obesidade periférica(RCQ≤0.85), n=11 e GC- controle, n=29. Na segunda parte, o estudo foi um ensaio clínico randomizado, cego e controlado com as mulheres obesas. Todas as voluntárias realizaram as avaliações antropométricas e cardiorrespiratórias. Para a avaliação da ventilação pulmonar foi utilizado a Pletismografia Optoeletrônica (POE) durante a respiração basal por um período de cinco minutos. Após randomizadas, as obesas formaram dois grupos: controle (GC) e intervenção Grupo Breath Stacking (GBS). Para a técnica de BS foi utilizado máscara facial com oclusão do ramo expiratório e ventilômetro de Wright. O GBS realizou três técnicas com intervalo de três minutos entre cada manobra, as imagens foram feitas por cinco minutos, antes e após as técnicas. O GC usou o mesmo circuito sem a oclusão do ramo expiratório e seguiu o mesmo protocolo de captação das imagens. Para a comparação entre os grupos foi realizado teste de análise de variância (ANOVA), com post-hoc de Bonferroni e correlação de Pearson para análise de associação entre o IMC, circunferência cintura (CC), circunferência quadril (CQ) e RCQ com as variáveis da ventilação pulmonar. Na segunda etapa, para a comparação dos grupos das variáveis antropométricas foi realizado o teste t não pareado, e para a espirometria e ventilação pulmonar antes e depois em cada grupo foi aplicado o teste t pareado. Resultados: Na primeira etapa, o GOC apresentou diferença na frequência respiratória, volume minuto (VM), tempo expiratório e nas variáveis espirométricas: VEF1 (p=0,00) e CVF (p=0,00) quando comparado ao GC. Na análise da ventilação pulmonar regional, foi encontrada nas obesas maior contribuição do volume corrente no compartimento abdominal (Vc,cab). Enquanto, no GC a maior contribuição foi no volume do compartimento torácico pulmonar (Vc,ctp). Houve correlação do Vc,ab com as variáveis antropométricas: IMC (r=+0,636;p=0,005), RCQ (r=+0,556;p=0,005) e CC (r=+0,,646;p=0,005). Na segunda etapa, o GBS apresentou aumento da contribuição do Vc,cta (p=0,04) e diminuição no Vc,ab (p=0,02), em relação aos valores absolutos do Vc nos compartimentos da caixa torácica. Antes e após a técnica o grupo GBS, não apresentou diferença nas variáveis espirométricas: VEF1(%), CVF(%), VEF1/CVF(%) e Capacidade Inspiratória (CI). Das variáveis da ventilação pulmonar a VM apresentou diminuição (p=0,03) no GBS. Conclusões: A obesidade em mulheres modifica o padrão de distribuição daventilação pulmonar total e regional em relação às mulheres de peso normal. Os dois tipos de obesidade apresentaram diferença na ventilação regional no compartimento abdominal. A obesidade central leva a padrão respiratório rápido e maior impacto na função pulmonar quanto à espirometria. Em relação ao efeito da técnica de BS houve maior contribuição no volume pulmonar na região inferior da caixa torácica. Houve uma redistribuição do volume entre os compartimentos, demonstrando a eficácia da técnica em ventilar áreas pulmonares basais

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