• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 32
  • 10
  • 4
  • 4
  • 4
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 80
  • 10
  • 7
  • 6
  • 6
  • 6
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 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

The finite element analysis of laminated composites

Lin, Fu Tien 07 April 2010 (has links)
Laminated plates with homogeneous isotropic layers in bending and extension were investigated by an analytical method. / Ph. D.
2

RECORDERS IN NETWORKED DATA ACQUISITION SYSTEMS

Grebe, David L. 10 1900 (has links)
International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / The role of recorders in telemetry applications has undergone many changes throughout the years. We’ve seen the evolution from multi-track tape to disk to solid state technologies, both for airborne and ground based equipment. Data acquisition and collection system design has changed as well and a recent trend in airborne is to merge acquisition and recording. On the ground, increased decentralization of data collection and processing has generated the requirement to provide backup storage to protect against communication circuit outages. This paper explores the trend to adopt network based data acquisition, collection, and distribution systems for telemetry applications and the impact on recording techniques and equipment. It shows that in this emerging approach the recorder returns to its root mission of attempting to provide the fastest, largest capacity for the least amount of investment. In a network based architecture the recorder need only accept and reproduce data operating independently from the acquisition process.
3

assemblage: a water taxi terminal for alexandria

Rogers, Taylor W. 10 February 2010 (has links)
projects start with a goal, an end to be realized. this project provided a platform to explore architecture. drawings, models, text and printmaking were used to this end. a project is found through the assembly of these pieces. these pages contain no finite conclusion on architecture. rather they illuminate the path I choose travel. where will my ideas take me from here? / Master of Architecture
4

Stress transfer between multi-seam longwall mines

Ganguli, Rajive 24 March 2009 (has links)
The future of most underground coal mining in the USA will entail the extraction of coal under multi-seam mining conditions. Mine design in such an environment will require the accurate prediction of stress transfer between adjacent seams. The available knowledge on criteria controlling stress transfer has been exhaustively reviewed and critical factors affecting multi-seam mining investigated. Young's Moduli of rock layers, thickness of rock layers, number of these layers and the coefficient of friction between these layers were identified as important parameters which affect stress transfer from mining of one seam to another. These parameters were studied using photoelastic methods and results analyzed both qualitatively and quantitatively. Finite element studies were also performed using UTAH2PC. Data obtained from field studies was used to correlate laboratory findings with prototype observations. Excellent correlation was obtained between laboratory and field data. Validity of the research is demonstrated using case studies. / Master of Science
5

Analysing layered security protocols

Gibson-Robinson, Thomas January 2013 (has links)
Many security protocols are built as the composition of an application-layer protocol and a secure transport protocol, such as TLS. There are many approaches to proving the correctness of such protocols. One popular approach is verification by abstraction, in which the correctness of the application-layer protocol is proven under the assumption that the transport layer satisfies certain properties, such as confidentiality. Following this approach, we adapt the strand spaces model in order to analyse application-layer protocols that depend on an underlying secure transport layer, including unilaterally authenticating secure transport protocols, such as unilateral TLS. Further, we develop proof rules that enable us to prove the correctness of application-layer protocols that use either unilateral or bilateral secure transport protocols. We then illustrate these rules by proving the correctness of WebAuth, a single-sign-on protocol that makes extensive use of unilateral TLS. In this thesis we also present a full proof of the model's soundness. In particular, we prove that, subject to a suitable independence assumption, if there is an attack against the application-layer protocol when layered on top of a particular secure transport protocol, then there is an attack against the abstracted model of the application-layer protocol. In contrast to existing work in this area, the independence assumption consists of eight statically-checkable conditions, meaning that it can be checked statically, rather than having to consider all possible runs of the protocol. Lastly, we extend the model to allow protocols that consist of an arbitrary number of layers to be proven correct. In this case, we prove the correctness of the intermediate layers using the high-level strand spaces model, by abstracting away from the underlying transport-layers. Further, we extend the above soundness results in order to prove that the multi-layer approach is sound. We illustrate the effectiveness of our technique by proving the correctness of a couple of simple multi-layer protocols.
6

Routing Protocols for Indoor Wireless Ad-Hoc Networks : A Cross-Layer Perspective

Dricot, Jean-Michel PP 01 June 2007 (has links)
The all-over trend for an universal access and ubiquitous access to the Internet is driving a revolution in our societies. In order to support this era of nomadic applications, new flexible network architectures have emerged. They are referred to as “wireless ad-hoc networks.” Since human-operated devices will more likely be used indoor, it leads to many issues related to the strength of the fading in this environment. Recently, it has been suggested that a possible interaction might exist between various parameters of the ad-hoc networks and, more precisely, between the propagation model and the routing protocol. To address this question, we present in this dissertation a cross-layer perspective of the analysis of these indoor ad-hoc networks. Our reasoning is made of four stages. First, the cross-layer interactions are analyzed by the means of multivariate statistical techniques. Since a cross-layering between the physical layer and the routing protocol has been proven to be significant, we further investigate the possible development a physical layer-constrained routing algorithm. Second, fundamental equations governing the wireless telecommunications systems are developed in order to provide insightful informations on how a reliable routing strategy should be implemented in a strongly-faded environment. After that, and in order to allow a better spatial reuse, the routing protocol we propose is further enhanced by the adjonction of a power control algorithm. This last feature is extensively analyzed and a closed-form expression of the link probability of outage in presence of non-homogeneous transmission powers is given. Numerous simulations corroborate the applicability and the performance of the derived protocol. Also, we evaluate the gain, in terms of radio channel ressources, that has been achieved by the means of the power control algorithm. Third, an architecture for the interconnection with a cellular network is investigated. A closed-form expression of the relaying stability of a node is given. This equation expresses the minimal requirement that a relaying node from the ad-hoc network must fullfil in order to bridge properly the connections to the base-station. Finally, a real-life implementation is provided as a validation of the applicability of this novel ad-hoc routing protocol. It is concluded that, both from the performance and the spatial re-use point-of-views, it can be taken advantage from the cross-layering between the physical and the routing layers to positively enhance the networking architectures deployed in an indoor environment.
7

Propagação vegetativa de Romãzeira (Punica granatum L.) / Vegetative propagation of pomegranate tree (Punica granatum L.)

Antonio Flávio Arruda Ferreira 30 January 2017 (has links)
No contexto atual de alimentos nutracêuticos, a romãzeira, frutífera exótica no Brasil, se destaca mundialmente pelo alto poder antioxidante e propriedades anti-inflamatórias, anticancerígenas e antidegenerativas, com pesquisas recentes e produtos disponibilizados no mercado farmacêutico e alimentício. Para aumentar a oferta do produto no mercado consumidor a implantação de cultivos comercias é a primeira etapa do processo. Porém, para o bom desenvolvimento da cultura o uso de mudas de qualidade e com características agronômicas adequadas são primordiais. Almejando essas propriedades, a propagação, é o caminho mais utilizado na fruticultura para a produção de mudas com alto vigor e produtividade. O objetivo deste trabalho foi avaliar os métodos de propagação por estaquia e alporquia para produção de mudas de romãzeira cv. Comum. Avaliou-se o uso de AIB (0, 500, 1000, 1500, 2000 mg L-1) na formação de raízes adventícias em estacas herbáceas, semi-lenhosas e lenhosas de romãzeira, nos períodos de inverno e primavera em ambiente com nebulização. Avaliou-se também, o uso de AIB nas concentrações de (0, 500, 1000, 1500, 2000 mg L-1), no enraizamento de alporques em ramos com 10 e 15 mm de diâmetros, nos períodos de inverno e primavera. Pode-se concluir que, em romãzeira cv. Comum, o método de estaquia é mais eficiente com a utilização de estacas caulinares semi-lenhosas e lenhosas no período de inverno, não necessitando nesta época da aplicação de AIB para estimular a formação de raízes. O método de alporquia proporciona elevadas porcentagens de enraizamento tanto na primavera quanto no inverno. Alporques em ramos com diâmetro de 15,0 mm apresentam maior matéria seca de raízes quando comparados aos ramos de 10,0 mm de diâmetro. O uso de AIB em alporques influencia no comprimento e no número de raízes formadas. Os alporques realizados no inverno apresentam maior matéria seca de raízes. Os materiais usados para a contenção do substrato nos alporques, polietileno e papel alumínio, não interferem no enraizamento da romãzeira. / In the current context of nutraceutical foods, the exotic, fruitful pomegranate in Brazil stands out worldwide for its high antioxidant power and anti-inflammatory, anticancer and antidegenerative properties, with recent research and products available in the pharmaceutical and food market. To increase the supply of the product in the consumer market the implantation of commercial crops is the first stage of the process. However, for the good development of the crop the use of quality seedlings and with suitable agronomic characteristics are primordial. Targeting these properties, propagation, is the most used path in fruit growing for the production of seedlings with high vigor and productivity. The objective of this work was to evaluate the methods of propagation by cuttings and air-layerings for the production of pomegranate seedlings cv. Common. It was evaluated the use of AIB (0, 500, 1000, 1500, 2000 mg L-1) in the formation of adventitious roots in herbaceous, semi-woody and woody piles of pomegranate, during winter and spring periods in the nebulized environment. It was also evaluated the use of AIB in the concentrations of (0, 500, 1000, 1500, 2000 mg L-1), in the rooting of air-layering in branches with 10 and 15 mm of diameter, in the winter and spring periods. It can be concluded that in pomegranate cv. Common, the cutting method is more efficient with the use of semi-woody and woody stem cuttings in the winter period and does not require the application of IBA to stimulate root formation at this time. The weeding method provides high rooting percentages in both spring and winter. Air-layerings in branches with a diameter of 15 mm show a higher dry matter of roots when compared to the branches of 10 mm in diameter. The use of AIB in air-layering influences the length and number of roots formed. The air-layering made in the winter present greater dry matter of roots. The materials used for the containment of the substrate in the air-layering, polyethylene and aluminum foil, do not interfere in the rooting of the pomegranate.
8

Propagação vegetativa de Romãzeira (Punica granatum L.) / Vegetative propagation of pomegranate tree (Punica granatum L.)

Ferreira, Antonio Flávio Arruda 30 January 2017 (has links)
No contexto atual de alimentos nutracêuticos, a romãzeira, frutífera exótica no Brasil, se destaca mundialmente pelo alto poder antioxidante e propriedades anti-inflamatórias, anticancerígenas e antidegenerativas, com pesquisas recentes e produtos disponibilizados no mercado farmacêutico e alimentício. Para aumentar a oferta do produto no mercado consumidor a implantação de cultivos comercias é a primeira etapa do processo. Porém, para o bom desenvolvimento da cultura o uso de mudas de qualidade e com características agronômicas adequadas são primordiais. Almejando essas propriedades, a propagação, é o caminho mais utilizado na fruticultura para a produção de mudas com alto vigor e produtividade. O objetivo deste trabalho foi avaliar os métodos de propagação por estaquia e alporquia para produção de mudas de romãzeira cv. Comum. Avaliou-se o uso de AIB (0, 500, 1000, 1500, 2000 mg L-1) na formação de raízes adventícias em estacas herbáceas, semi-lenhosas e lenhosas de romãzeira, nos períodos de inverno e primavera em ambiente com nebulização. Avaliou-se também, o uso de AIB nas concentrações de (0, 500, 1000, 1500, 2000 mg L-1), no enraizamento de alporques em ramos com 10 e 15 mm de diâmetros, nos períodos de inverno e primavera. Pode-se concluir que, em romãzeira cv. Comum, o método de estaquia é mais eficiente com a utilização de estacas caulinares semi-lenhosas e lenhosas no período de inverno, não necessitando nesta época da aplicação de AIB para estimular a formação de raízes. O método de alporquia proporciona elevadas porcentagens de enraizamento tanto na primavera quanto no inverno. Alporques em ramos com diâmetro de 15,0 mm apresentam maior matéria seca de raízes quando comparados aos ramos de 10,0 mm de diâmetro. O uso de AIB em alporques influencia no comprimento e no número de raízes formadas. Os alporques realizados no inverno apresentam maior matéria seca de raízes. Os materiais usados para a contenção do substrato nos alporques, polietileno e papel alumínio, não interferem no enraizamento da romãzeira. / In the current context of nutraceutical foods, the exotic, fruitful pomegranate in Brazil stands out worldwide for its high antioxidant power and anti-inflammatory, anticancer and antidegenerative properties, with recent research and products available in the pharmaceutical and food market. To increase the supply of the product in the consumer market the implantation of commercial crops is the first stage of the process. However, for the good development of the crop the use of quality seedlings and with suitable agronomic characteristics are primordial. Targeting these properties, propagation, is the most used path in fruit growing for the production of seedlings with high vigor and productivity. The objective of this work was to evaluate the methods of propagation by cuttings and air-layerings for the production of pomegranate seedlings cv. Common. It was evaluated the use of AIB (0, 500, 1000, 1500, 2000 mg L-1) in the formation of adventitious roots in herbaceous, semi-woody and woody piles of pomegranate, during winter and spring periods in the nebulized environment. It was also evaluated the use of AIB in the concentrations of (0, 500, 1000, 1500, 2000 mg L-1), in the rooting of air-layering in branches with 10 and 15 mm of diameter, in the winter and spring periods. It can be concluded that in pomegranate cv. Common, the cutting method is more efficient with the use of semi-woody and woody stem cuttings in the winter period and does not require the application of IBA to stimulate root formation at this time. The weeding method provides high rooting percentages in both spring and winter. Air-layerings in branches with a diameter of 15 mm show a higher dry matter of roots when compared to the branches of 10 mm in diameter. The use of AIB in air-layering influences the length and number of roots formed. The air-layering made in the winter present greater dry matter of roots. The materials used for the containment of the substrate in the air-layering, polyethylene and aluminum foil, do not interfere in the rooting of the pomegranate.
9

CONSTRAINING MARTIAN SEDIMENTATION VIA ANALYSIS OF STRATAL PACKAGING, INTRACRATER LAYERED DEPOSITS, ARABIA TERRA, MARS

Cadieux, Sarah Beth 01 May 2011 (has links)
Craters within Arabia Terra, Mars, contain hundreds of meters of layered strata showing systematic alternation between slope- and cliff-forming units, suggesting either rhythmic deposition of distinct lithologies or lithologies that experienced differential cementation. Hypothesized origins of these intercrater layered deposits include lacustrine, aeolian, volcanic airfall, and impact surge deposition. On Earth, rhythmically deposited strata can be examined in terms of stratal packaging, wherein the interplay of tectonics, sediment deposition, and change in base level results in predictable patterns with respect to changes in the amount of space available for sediment accumulation. Fundamental differences between tectonic regimes of Earth and Mars demand that packaging of layered strata primarily reflects changes in sediment influx and base level. Analysis of stratal packaging may therefore help us understand the relative roles of these parameters, and provide crucial constraint on martian depositional models. Rhythmic stratal patterns in Becquerel Crater (7°W 22°N) have been attributed to astronomical forcing of regional climate. A clear depositional model, however, has yet to be presented. Here, we reanalyze strata of Becquerel Crater and compare results with two additional crater successions. Results indicate that, by contrast with Becquerel Crater, strata within Danielson Crater (7°W 8°N) and an unnamed crater (Crater X; 1.2°W 9°N) do not record hierarchical packaging readily attributable to astronomical effects, and suggest that regional climate forcing may not be readily applied as a paradigm for all intracrater deposition. Similarities in depositional style in these three craters, however, may be linked by a model for sediment accumulation—with potential links to regional climate—wherein episodic melting of ground ice raised local base level, stabilized aeolian sedimentation, and resulted in differential cementation of accumulated strata.
10

SEXUAL AND ASEXUAL REPRODUCTIVE CHARACTERISTICS OF THE NORTH AMERICAN PAWPAW [<i>ASIMINA TRILOBA</i> (L.) DUNAL]

Crabtree, Sheri Beth 01 January 2004 (has links)
The North American Pawpaw [Asimina triloba (L.) Dunal] shows great potential as a new fruit crop. Kentucky State University in Frankfort, Ky. is the site for the USDA National Clonal Germplasm Repository (NCGR) for Asimina species. Both the fruit and the trees themselves are of high value to growers and nursery producers. Pawpaw cultivars are currently propagated by grafting or budding onto seedling rootstock; no method currently exists to clonally propagate pawpaw on its own roots. Three methods of layering were attempted in this study to clonally propagate pawpaw: trench layering, pot layering, and mound layering. Both trench layering and pot layering experiments showed the importance of both juvenility and auxin application in adventitious rooting of pawpaw. Although rooting of more mature pawpaw shoots in these experiments did not exceed 30%, these propagation methods were more successful then previous attempts at rooting more mature pawpaw stems. Mound layering was less successful, but an easierto-root genotype of pawpaw in the KSU-USDA NCGR for Asimina spp. was discovered that may show promise for future propagation studies. Diversity in reproductive characteristics of pawpaw was also assessed in this study. Accessions in the KSU-USDA repository orchard collected from six different geographic regions were selected and trunk cross sectional area, total number of flowers, length of flowering, flowering peak, fruit set, total number of clusters, total number of fruit, number of fruit per cluster, average fruit weight, yield by weight, yield efficiency, length of harvest, harvest peak, and growing degree days required for ripening were evaluated. Significant differences were found among the regions in most of the characteristics evaluated. Correlations were also found between several vegetative and reproductive characteristics. This indicates that a significant level of reproductive diversity exists within KSUs repository collection, and between pawpaws collected from different regions of the native range.

Page generated in 0.0674 seconds