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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.
291

Three dimensional evaluation of the TMJ condyle position in different types of skeletal patterns

Guedes, Ines H. 06 March 2014 (has links)
Objective: To evaluate three-dimensional position of the TMJ condyle within the glenoid fossa in different types of skeletal patterns. Materials and methods: Ninety CBCT images were consecutively selected and divided into skeletal class I, class II and class III. The images were analyzed locating landmarks in the different areas of the condyle and glenoid fossa. All landmarks presented acceptable reliability. The mean results were compared using ANOVA and Bonferroni post-hoc test (p < 0.05). Results: There was a tendency for the anterior joint space to be smaller than the posterior joint space. Statistical analysis, however, evidenced no significant differences between the anterior, superior and posterior joint spaces and the different skeletal patterns or between sides. Conclusion: There was non-concentricity of the condyle for all the groups studied, and no particular direction was statistically significantly favored. It is unclear whether the differences found would be clinically significant, considering anatomical individual variations.
292

Trimačių galerijų šablonų generavimas / Generation of three-dimensional gallery patterns

Zigmantaitė, Danguolė 27 August 2009 (has links)
Šiame darbe apžvelgtos įvairios trimatės galerijos ir jų kūrimo principai. Atlikta programų ir įrankių, skirtų galerijoms kurti, analizė. Atlikta VRML programavimo kalbos galimybių ir jos taikymų trimatės grafikos sistemose analizė. Supažindinama su šablonų generavimo būdais. Atlikta įskiepų, skirtų trimačių galerijų naršyklėse peržiūrai, analizė. Panaudojant ArchiCad projektavimo įrankį ir VRML kalbą, sukurtas trimatis galerijos šablonas. / This paper reviews various three – dimensional galleries and their development principles. There was made an analysis of programmes and tools, which were designed for the creation of galleries. The analysis was also made of VRLM programming language – its options and applications in three–dimensional graphics systems. This work acquaints with methods of template generation. There was made an analysis of plugins, which are intended for the viewing in the browsers of three–dimensional galleries. There was created the three–dimensional template of the gallery, by using ArchiCad and VRML design tool.
293

ROLE OF CELL ADHESION MICROENVIRONMENT AND THE SRC/STAT3 AXIS IN AUTOCRINE HGF SIGNALING DURING BREAST TUMOURIGENESIS

Starova, BLERTA 22 September 2008 (has links)
Over-expression of both hepatocyte growth factor (HGF) and its receptor Met frequently occurs in invasive human breast cancer, suggesting that the establishment of an HGF “autocrine loop” may be linked to breast tumour progression. We have recently shown a novel activating function of two signaling molecules, Src tyrosine kinase and the signal transducer and activator of transcription-3 factor (Stat3), on HGF expression in breast epithelial cells. Interestingly, Stat3 is also important in normal breast development,but this function does not require Src. In addition, β1-integrin adhesion occurs minimally in differentiated breast epithelium, but is upregulated during oncogenic progression and is required for transformation by Src. We therefore hypothesize that β1-integrin engagement is necessary for Src/Stat3-dependent activation of HGF transcription and breast tumourigensis. Using specific inhibitors of Src (Dasatinib) and Stat3 (CPA7) we demonstrated that autocrine HGF expression is linked to activation of Src/Stat3 in a malignant breast cell line. Phenotypic reversion (e.g., cell rounding and loss of filopodial extensions) and inhibition of pY705Stat3, HGF and pYMet expression as determined by immunofluorescence was achieved with both inhibitor treatments separately, and a synergistic effect was observed with combined treatment. Furthermore, β-catenin localization was nuclear in malignant cells, but shifted to cortical cytoplasmic following inhibitor treatment, similar to non-malignant mouse breast epithelial cells (EPH4). We are currently extrapolating these findings to a 3D Matrigel culture model in which EPH4 cells form acini-like spheroids with hollow lumen surrounded by a well-polarized outer layer of cells. Under these conditions, Stat3 levels are decreased followed by a reduction in cyclin D1 expression, while Src activation remains at a low baseline level. Interestingly,expression of Stat5, which has a reciprocal relationship with Stat3 in breast development and involution, is increased concomitant with elevated β-casein expression. Moreover, Fibronectin and HGF in combination stimulate tubular outgrowths with lumen filling. These findings suggest that aberrant changes in extracellular matrix milieu may stimulate integrin cross talk resulting in a switch of HGF/Met signaling to a transformation phenotype. Information from this study may lead to novel cancer therapies through targeting the HGF/Met and integrin signaling cascades. / Thesis (Master, Pathology & Molecular Medicine) -- Queen's University, 2008-09-19 18:19:22.744
294

Three-dimensional kinematic model of a task specific motion based on instantaneous screw axis theory developed for golf motion analysis

Vena, Alessandro S Unknown Date
No description available.
295

Two and three dimensional cephalometric assessment of dental and skeletal changes following orthodontic treatment with Damon passive self-ligating system

Ehsani, Sayeh Unknown Date
No description available.
296

Design and Use of Servo-Driven Actuators for Spanwise-Varying Control of a Backward-Facing Step Flow

Schostek, Marc A. Unknown Date
No description available.
297

Modeling the hydraulic characteristics of fully developed flow in corrugated steel pipe culverts

Toews, Jonathan Scott 25 September 2012 (has links)
The process of fish migration within rivers and streams is important, especially during the spawning season which often coincides with peak spring discharges in Manitoba. Current environmental regulations for fish passage through culverts require that the average velocity be limited to the prolonged swimming speed of the fish species present. In order to examine the validity of this approach, physical model results were used to calibrate and test a commercially available Computational Fluid Dynamics (CFD) model. Detailed analysis showed that CFD models and the empirical equations used were both able to give a better representation of the flow field than the average velocity. However, the empirical equations were able to provide a more accurate velocity distribution within the fully developed region. A relationship was then developed, to estimate the cumulative percent area less than a threshold velocity within CSP culverts, to be used as a guideline during the design phase.
298

Interaction techniques for common tasks in immersive virtual environments : design, evaluation, and application

Bowman, Douglas A. January 1999 (has links)
No description available.
299

Three-Dimensional Patterning Using Ultraviolet Curable Nanoimprint Lithography.

Mohamed, Khairudin January 2009 (has links)
Although a large number of works on nanoimprint lithography (NIL) techniques have been reported, the the ability for three-dimensional (3-D) patterning using NIL has not been fully addressed in terms of the mold fabrication and imprint processes. Patterning 3-D and multilevel features are important because they eliminate multiple steps and complex interlevel alignments in the nanofabrication process. The 3-D and multilevel mold design and fabrication, and imprint processes have been studied and investigated in this research work. In the UV-NIL technique, a transparent mold with micro/nanostructure patterns on its surface is allowed to be replicated on UV curable polymer without the need of high applied pressure or temperature. UV-NIL has the potential to fabricate micro/nanostructures with high resolution, high reproducibility, low cost, high throughput and is capable of 3-D patterning. This research focuses on two aspects; the development of mold making and imprint processes. In the process of making a master mold, an EBL technique was employed for writing patterns on e-beam resists. PMMA positive resist was used for 2-D patterning and ma-N2403 negative resist from Microresist Technology was used for 3-D patterning. After being developed, the 3-D mold pattern was transferred onto quartz substrate using a single-step reactive ion etching (RIE) technique. A number of challenging issues such as surface charging, electron scattering and proximity effects surfaced during the EBL pattern writing on insulating and transparent molds. A number of new approaches have been developed for suppressing the charging effects in the 2-D and 3-D patterning. Using thin metallic coating on the quartz substrates or on top of the resist, or conductive polymer coating using PEDOT/PSS on top of the resist has demonstrated excellent results in a 2-D structure with a high aspect-ratio of 1:10 and feature sizes down to 60 nm. In 3-D patterning, two approaches have been followed; the critical energy method and/or a top coating of conductive polymer (PEDOT/PSS) layer. Isolated 3-D structures with feature sizes down to 500 nm were successfully fabricated using the first method while by using the second method, dense 3-D structures patterns with feature sizes down to 300 nm, on 400 nm pitch have been demonstrated. In UV-NIL, the surface roughness Rq(rms) should be less than 5 nm, which is important for replicating optical structures and devices. In this work, the RIE process been optimized to yield 2 nm roughness on a patterned quartz surface. This was achieved by optimizing the RIE process pressure of below 6 mTorr. The other part of this thesis is on replication or imprinting of 2-D and 3-D structures. In the process of replicating the master mold profiles, the imprint processes were carried out using a vacuum operated manual imprint tool which was attached to a Mask Aligner UV illumination system. In 2-D imprinting, resist sticking on the vertical side wall was the main issue, especially on high aspect ratio structures. Meanwhile in 3-D imprinting, the imprint results have shown good reproducibility in up to 15 imprint cycles, where the issue of Ormocomp soft/daughter mold cracking after long UV exposure had limited the repetition of the imprint cycles. In this thesis, the 2-D and 3-D resist patterning on insulating substrates using the EBL technique have been demonstrated with the assistance of a number of developed charge suppression methods. Single-step RIE pattern transfer onto quartz substrates with surface roughness below 5nm has been achieved. Replication of 3-D and multilevel structures reliably make the UV-NIL technique suitable for future applications such as surface texturing, optical devices and many other complex structures including MEMS.
300

Camera calibration for a three-dimensional range finding system

Zhang, Jinlei January 1995 (has links)
The purpose of this project is to develop the procedures to perform the camera calibration in a three dimension range finding system. The goal is to have a system that will provide reasonably accurate range data which can be used in further three-dimensional computer vision research such as edge detection, surface recovery and object recognition. In this project, an active lighting, optical, triangulation based range finding system has been developed. The software system is designed in object oriented technology and implemented using the C++ programming language. The overall performance of the system is investigated and the system has achieved 0.5 mm (or 4%) accuracy. A review of three range data acquisition techniques is given. Based on the analysis to the current system, suggestions to future improvement are also provided. / Department of Physics and Astronomy

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