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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

The in-situ data analysis for infragravity edge wave and its application in tsunami and typhoon waves

Chien, Hsiao-ching 12 February 2009 (has links)
The edge wave is a kind of infragravity wave. It¡¦s forcing and evolu- ion are different from common progressive waves. It may damage the co- astal area when a wave incident to the shore with an angle is reflected and reflected back by topography. In this thesis,by AWCP deployed near Kao- hsiung and Hualien harbor,the flow and surface elevation of the tsunami generated in PingTung earthquake and typhoon waves are analyzed.By assuming uni-directional progressive waves and HHT, the theoretical solution is used to check if the edge wave exists. The primary results suggest that Stokes edge wave is a significant component of the tsunami in Kaohsiung area and it might be generated when the tsunami arrived the DongGung or SGC.The infragravity wave generated by typhoon waves in typhoon Kaemi, Bopha and Hugupit are also edge waves by the relation between pressure and flow.That means edge waves be generated by typhoon waves outside the Hualien harbor will transport low frequence energy to the the harbor basin and cause the resonance of Hualien harbor.
2

Domination Edge Lift Critical Trees

Desormeaux, Wyatt J., Haynes, Teresa W., Henning, Michael A. 01 March 2012 (has links)
Let uxv be an induced path with center x in a graph G. The edge lifting of uv off x is defined as the action of removing edges ux and vx from the edge set of G, while adding the edge uv to the edge set of G. We study trees for which every possible edge lift changes the domination number. We show that there are no trees for which every possible edge lift decreases the domination number. Trees for which every possible edge lift increases the domination number are characterized.
3

On the Depression of Graphs

Schurch, Mark 17 April 2013 (has links)
An edge ordering of a graph G = (V,E) is an injection f : E → R, where R denotes the set of real numbers. A path in G for which the edge ordering f increases along its edge sequence is called an f-ascent; an f-ascent is maximal if it is not contained in a longer f-ascent. The depression of G is the smallest integer k such that any edge ordering f has a maximal f-ascent of length at most k. In this dissertation we discuss various results relating to the depression of a graph. We determine a formula for the depression of the class of trees known as double spiders. A k-kernel of a graph G is a set of vertices U ⊆ V (G) such that for any edge ordering f of G there exists a maximal f-ascent of length at most k which neither starts nor ends in U. We study the concept of k-kernels and discuss related depression results, including an improved upper bound for the depression of trees. We include a characterization of the class of graphs with depression three and without adjacent vertices of degree three or higher, and also construct a large class of graphs with depression three which contains graphs with adjacent vertices of high degree. Lastly, we apply the concept of ascents to edge colourings using possibly fewer than |E(G)| colours (integers). We consider the problem of determining the minimum number of colours for which there exists an edge colouring such that the length of a shortest maximal path of edges with increasing colors has a given length. / Graduate / 0405
4

Explicit data graph compilation

Smith, Aaron Lee, 1977- 19 August 2010 (has links)
Technology trends such as growing wire delays, power consumption limits, and diminishing clock rate improvements, present conventional instruction set architectures such as RISC, CISC, and VLIW with difficult challenges. To show continued performance growth, future microprocessors must exploit concurrency power efficiently. An important question for any future system is the division of responsibilities between programmer, compiler, and hardware to discover and exploit concurrency. In this research we develop the first compiler for an Explicit Data Graph Execution (EDGE) architecture and show how to solve the new challenge of compiling to a block-based architecture. In EDGE architectures, the compiler is responsible for partitioning the program into a sequence of structured blocks that logically execute atomically. The EDGE ISA defines the structure of, and the restrictions on, these blocks. The TRIPS prototype processor is an EDGE architecture that employs four restrictions on blocks intended to strike a balance between software and hardware complexity. They are: (1) fixed block sizes (maximum of 128 instructions), (2) restricted number of loads and stores (no more than 32 may issue per block), (3) restricted register accesses (no more than eight reads and eight writes to each of four banks per block), and (4) constant number of block outputs (each block must always generate a constant number of register writes and stores, plus exactly one branch). The challenges addressed in this thesis are twofold. First, we develop the algorithms and internal representations necessary to support the new structural constraints imposed by the block-based EDGE execution model. This first step provides correct execution and demonstrates the feasibility of EDGE compilers. Next, we show how to optimize blocks using a dataflow predication model and provide results showing how the compiler is meeting this challenge on the SPEC2000 benchmarks. Using basic blocks as the baseline performance, we show that optimizations utilizing the dataflow predication model achieve up to 64% speedup on SPEC2000 with an average speedup of 31%. / text
5

Power dissipation in a divertor plasma

Weber, S. January 1993 (has links)
No description available.
6

Regularity of Powers of Edge Ideals

January 2017 (has links)
acase@tulane.edu / Let $G$ be a finite simple graph and let $I = I(G)$ be its edge ideal. Main goal in this thesis is to relate algebraic invariants of powers of edge ideals and combinatorial data of graphs. In particular, we focus on the Castelnuovo-Mumford regularity of an edge ideal and its powers. The first part of this thesis focuses on regularity of edge ideals. In that regard, we give new bounds on the regularity of $I$ when $G$ contains a Hamiltonian path and when $G$ is a Hamiltonian graph. Moreover, we explicitly compute the regularity of unicyclic graphs and characterize the unicyclic graphs with regularity $\nu(G)+1$ and $\nu(G)+2$ where $\nu(G)$ denotes the induced matching number of $G.$ The second problem is on the regularity of powers of edge ideals. Let $R=k[x_1, \ldots, x_n]$ be a polynomial ring and let $I \subset R$ be a homogeneous ideal. It is a celebrated result of Cutkosky, Herzog,Trung \cite{CHT}, Kodiyalam \cite{Kodi}, Trung and Wang \cite{TW} that regularity of $I^s$ is asymptotically a linear function for $s \gg 0,$ i.e., $as+b$ for integers $a,b$ and $s_0$ when $s \geq s_0.$ It is known that $a$ is equal to 2 when $I=I(G)$ is the edge ideal of a graph. We then turn on our focus on identifying $b$ and $s_0$ via combinatorial data of the graph $G.$ We explicitly compute the regularity of $I^s$ for all $s\geq 1$ when $G$ is a forest, a cycle and a unicyclic graph. We also present a lower bound on the regularity of powers of edge ideals in terms of the induced matching number of a graph. / 1 / Selvi Beyarslan
7

Automatic Video Object Segmentation Method with Predictive Extending Edge

Lai, Yi-Tung 23 June 2004 (has links)
Recently, for the new demands of nowadays multimedia system, such as video interaction, the MPEG-4 standard has been designed. In MPEG-4, because of those new demands of nowadays multimedia system the video stream can be divided into several video object planes ( VOPs ). Those VOPs can be separately encoded, stored, or transmitted. VOP is the basic interactive unit in MPEG-4 video stream, how to automatically or semi-automatically separate appropriate VOPs from an image sequence has become one of the most important issues for an MPEG-4 system, which is also the goal of this proposal. However, MPEG-4 does not provide concrete techniques for VOP extraction. Nonetheless, it is very difficult to extract VOPs, thus the preprocessing used to decompose sequences into VOPs becomes an important issue for an MPEG-4 system, which is also the goal of this thesis. In this thesis, we will develop techniques for segmenting images contained in an image sequence, which can separate two or more image segments ( or regions ) from MPEG-4 test image sequences, and those image segments can be coded as MPEG-4 VOPs. First, we utilize the feature of wavelet to improve the change detection, such that we can obtain a better result of the moving object edge by improved change detection. Second, we use an edge-based method for tracking boundary which is using the canny edge detection and the connected edge component labeling to label those edges. Third, we can combine those two information to obtain a more complete boundary by extracting moving object edges. Although we catch all the edges which is detected on the location of the true boundary, it usually occurs some gaps on which we catch. Because it sometimes will not have a clear boundary, we have to find some method to complete these gaps. Therefore, we propose a multi-level prediction scheme to complete the gaps between the disjoint edges of the boundary we caught by extending the edges on the predictive direction. Final, we use a simple connecting operation for the little gaps (distance=1 or 2). That will make the result more close and smooth. Experimental results for several test sequences show that this novel automatic video segmentation algorithm can give a more accurate object masks.
8

Short Cavity, Single-Frequency Edge-Emitting Laser with Fiber Grating

Liu, Ching-Chen 10 July 2006 (has links)
Short cavity lasers have several advantages such as improved output linearity in comparison with long lasers, longitudinal oscillation mode stabilized against the injection level and the operating temperature, and large mode spacing for allowing single-mode operation. In this paper, a short cavity laser has been successfully fabricated. The waveguides of laser diodes were formed by wet-etching with width of 4£gm. A SiO2 thin film was then sputtered onto the sample as surface passivation layer, after that, a PMGI polymer was spun on the sample and used for opening ridge window of metalization. After the SiO2 layers on the top of the ridge were removed, the metalizations were deposited for contact. The final finished laser was 200£gm long. The turn on voltage of the laser diode is 0.8 V with total resistance of 9.8£[. In the CW operation, the threshold current of laser is 20mA with threshold voltage of 1.3V, reaching total output optical power of 8mW at 50mA and 12mW at 70mA. The small signal frequency response is 8GHz (current 70mA). By adopting fiber grating and circulator to filter the main mode, the side mode suppression ratio (SMSR) of single longitudinal mode is about 40dB, showing single mode operation.
9

Receptivity of Boundary Layers under Pressure Gradient

Schrader, Lars-Uve January 2008 (has links)
<p>Boundary-layer flow over bodies such as aircraft wings or turbine blades is characterized by a pressure gradient due to the curved surface of the body. The boundary layer may experience modal and non-modal instability, and the type of dominant instability depends on whether the body is swept with respect to the oncoming flow or not. The growth of these disturbances causes transition of the boundary-layer flow to turbulence. Provided that they are convective in nature, the instabilities will only arise and persist if the boundary layer is continuously exposed to a perturbation environment. This may for example consist of turbulent fluctuations or sound waves in the free stream or of non-uniformities on the surface of the body. In engineering, it is of relevance to understand how susceptive to such perturbations the boundary layer is, and this issue is subject of <em>receptivity analysis</em>.</p><p> </p><p>In this thesis, receptivity of simplified prototypes for flow past a wing is studied. In particular, the three-dimensional swept-plate boundary layer and the boundary layer forming on a flat plate with elliptic leading edge are considered. The response of the boundary layer to vortical free-stream disturbances and surface roughness is analyzed, receptivity mechanisms are identified and their efficiency is quantified.</p> / 76218 VR Receptivity
10

Both hands

Lendzian, Daniel Francis 16 September 2013 (has links)
This thesis is an in-depth analysis of the role of Voice in Suzan Zeder’s The Edge of Peace. A brief description of the author’s acting work before matriculating into The University of Texas’ MFA Acting program is described. The author then describes the skills learned in graduate school needed to perform the role both in Texas and Seattle. He briefly describes prior acting work at the University, and details some plans for the future of his acting career. / text

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