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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.
581

Die SLUB bloggt und twittert

Bonte, Achim, Heide, Thomas 23 September 2009 (has links) (PDF)
... Im Interesse eines lebendigen Dialogs mit ihrer weitaus größten Benutzergruppe hat sich die SLUB im Frühjahr 2009 entschlossen, die Klaviatur der sozialen Netzwerke, der Blogs und Mikro-Blogs, planmäßig zu nutzen. Erklärte Ziele sind die möglichst zielgruppengerechte Vermittlung und beschleunigte Optimierung der Bibliotheksdienstleistungen sowie eine hohe Identifikation der Studierenden mit „ihrer“ Bibliothek. Die SLUB zählt zu den ersten Bibliotheken in Deutschland, die die neuen Werkzeuge konsequent einsetzt, jedoch kann kein Zweifel bestehen, dass die Kommunikation via Blogs und Mikro-Blogs recht bald weithin zum bibliothekarischen Alltag gehören wird. ...
582

Turbo Decoding With Early State Decisions

Lindblom, Johannes January 2008 (has links)
<p>Turbo codes was first presented in 1993 by C. Berrou, A. Glavieux and P. Thitimajshima. Since then this class of error correcting codes has become one of the most popular, because of its good properties. The turbo codes are able to come very close to theoretical limit, the Shannon limit. Turbo codes are for example used in the third generation of mobile phone (3G) and in the standard IEEE 802.16 (WiMAX).</p><p>There are some drawbacks with the algorithm for decoding turbo codes. The deocoder uses a Maximum A Posteriori (MAP) algorithm, which is a complex algorith. Because of the use of many variables in the decoder the decoding circuit will consume a lot of power due to memory accesses and internal communication. One way in which this can be reduced is to make early decisions.</p><p>In this work I have focused on making early decision of the encoder states. One major part of the work was also to be sure that the expressions were written in a way that as few variables as possible are needed. A termination condition is also introduced. Simulations based on estimations of the number of memory accesses, shows that the number of memory accesses will significantly decrease.</p>
583

Arrowmont at Loghaven craft and art /

Bailey, Karen January 2009 (has links)
Thesis (M. Arch.)--University of Tennessee, Knoxville, 2009. / Title from title page screen (viewed on Mar. 11, 2010). Thesis advisor: William Rudd. Vita. Bailey appendix II.pdf (18364 KB) link located at bottom of [Article summary page]. Includes bibliographical references.
584

A Note on Transformed Density Rejection

Leydold, Josef January 1999 (has links) (PDF)
In this paper we describe a version of transformed density rejection that requires less uniform random numbers. Random variates below the squeeze are generated by inversion. For the expensive part between squeeze and density an algorithm that uses a coverering with triangles is introduced. (author's abstract) / Series: Preprint Series / Department of Applied Statistics and Data Processing
585

Short Universal Generators Via Generalized Ratio-of-Uniforms Method

Leydold, Josef January 2000 (has links) (PDF)
We use inequalities to design short universal algorithms that can be used to generate random variates from large classes of univariate continuous or discrete distributions (including all log-concave distributions). The expected time is uniformly bounded over all these distributions for a particular generator. The algorithms can be implemented in a few lines of high level language code. (author's abstract) / Series: Preprint Series / Department of Applied Statistics and Data Processing
586

Optimal transport, free boundary regularity, and stability results for geometric and functional inequalities

Indrei, Emanuel Gabriel 01 July 2013 (has links)
We investigate stability for certain geometric and functional inequalities and address the regularity of the free boundary for a problem arising in optimal transport theory. More specifically, stability estimates are obtained for the relative isoperimetric inequality inside convex cones and the Gaussian log-Sobolev inequality for a two parameter family of functions. Thereafter, away from a ``small" singular set, local C^{1,\alpha} regularity of the free boundary is achieved in the optimal partial transport problem. Furthermore, a technique is developed and implemented for estimating the Hausdorff dimension of the singular set. We conclude with a corresponding regularity theory on Riemannian manifolds. / text
587

Inversion-based petrophysical interpretation of logging-while-drilling nuclear and resistivity measurements

Ijasan, Olabode 01 October 2013 (has links)
Undulating well trajectories are often drilled to improve length exposure to rock formations, target desirable hydrocarbon-saturated zones, and enhance resolution of borehole measurements. Despite these merits, undulating wells can introduce adverse conditions to the interpretation of borehole measurements which are seldom observed in vertical wells penetrating horizontal layers. Common examples are polarization horns observed across formation bed boundaries in borehole resistivity measurements acquired in highly-deviated wells. Consequently, conventional interpretation practices developed for vertical wells can yield inaccurate results in HA/HZ wells. A reliable approach to account for well trajectory and bed-boundary effects in the petrophysical interpretation of well logs is the application of forward and inverse modeling techniques because of their explicit use of measurement response functions. The main objective of this dissertation is to develop inversion-based petrophysical interpretation methods that quantitatively integrate logging-while-drilling (LWD) multi-sector nuclear (i.e., density, neutron porosity, photoelectric factor, natural gamma ray) and multi-array propagation resistivity measurements. Under the assumption of a multi-layer formation model, the inversion approach estimates formation properties specific to a given measurement domain by numerically reproducing the available measurements. Subsequently, compositional multi-mineral analysis of inverted layer-by-layer properties is implemented for volumetric estimation of rock and fluid constituents. The most important prerequisite for efficient petrophysical inversion is fast and accurate forward models that incorporate specific measurement response functions for numerical simulation of LWD measurements. In the nuclear measurement domain, first-order perturbation theory and flux sensitivity functions (FSFs) are reliable and accurate for rapid numerical simulation. Albeit efficient, these first-order approximations can be inaccurate when modeling neutron porosity logs, especially in the presence of borehole environmental effects (tool standoff or/and invasion) and across highly contrasting beds and complex formation geometries. Accordingly, a secondary thrust of this dissertation is the introduction of two new methods for improving the accuracy of rapid numerical simulation of LWD neutron porosity measurements. The two methods include: (1) a neutron-density petrophysical parameterization approach for describing formation macroscopic cross section, and (2) a one-group neutron diffusion flux-difference method for estimating perturbed spatial neutron porosity fluxes. Both methods are validated with full Monte Carlo (MC) calculations of spatial neutron detector FSFs and subsequent simulations of neutron porosity logs in the presence of LWD azimuthal standoff, invasion, and highly dipping beds. Analysis of field and synthetic verification examples with the combined resistivity-nuclear inversion method confirms that inversion-based estimation of hydrocarbon pore volume in HA/HZ wells is more accurate than conventional well-log analysis. Estimated hydrocarbon pore volume from conventional analysis can give rise to errors as high as 15% in undulating HA/HZ intervals. / text
588

Evaluating profitability of solid timber production from 15 year old pruned and thinned Eucalyptus nitens (Deane & Maiden) in Canterbury

Satchell, Stuart Dean January 2015 (has links)
This case study investigated profitability of a small stand of fast-grown Eucalyptus nitens in Canterbury for sawn timber production. This stand was pruned and thinned and then harvested at 15 years old. An estimate of per-hectare log yields and diameters was made from the stand. Sample logs were sawn, dried and profiled, then products quantified. Log prices were estimated using the residual value method. Prices were summed for sawn products from each log, from which processing expenses and sawmill profit were deducted for an estimate of log value. In the absence of market prices for sawn E. nitens products empirical estimates of price were derived from market survey data. Predictive models were produced from estimated stand log yields along with predicted product revenues and processing costs from sample logs. These were used for estimating per-hectare log residual values from the case study stand trees. Financial returns to the grower were then calculated as discounted cash flows from the estimated log residual values per hectare, taking into account grower costs along with harvesting and transport costs. Best-practice processing methods were identified from the literature and applied as a productivity benchmark. Methods were developed with the view to standardising data across research efforts that seek to improve grade recoveries for E. nitens. A range of factors were investigated that potentially influenced E. nitens log residual value in this case study, including log diameter and log position. Outcomes included a reasonably favourable return on investment for the grower. However, this depended on a number of factors such as land price, distance from processor, product prices, grading methods, drying methods and level of sawmill profit. The application of contemporary best practice small-scale processing methods indicates that E. nitens has potential as a profitable plantation species for solid timber production.
589

The Predictability of Speculative Bubbles : An examination of the log-periodic power law model

Gustavsson, Marcus, Levén, Daniel January 2015 (has links)
In this thesis we examine the ability of the log-periodic power law model to accurately predict the end of speculative bubbles on financial markets through modeling of asset price dynamics on a selection of historical bubbles. The methods we use are based on a nonlinear least squares estimation which yields predictions of when the bubble will change regime.We find evidence which support the occurrence of LPPL-patterns leading up to the change in regime; asset prices during bubble periods seem to oscillate around a faster-than-exponential growth. In most cases the estimation yields accurate predictions, although we conclude that the predictions are quite dependent on at which point in time the prediction is conducted. We also find that the end of a speculative bubble seems to be influenced by both endogenous speculative growth and exogenous factors. For this reason we propose a new way of interpreting the predictions of the model, where the end dates should be interpreted as the start of a time period where the asset prices are especially sensitive to exogenous events. We propose that negative news during this time period results in a regime shift of the bubble. This study is the first to address both the possibilities and the limitations of the LPPL-model, and should therefore be considered as a contribution to the academia.
590

手機使用者於電量管理之行為模式分析 / User Behavior Analysis of Power Management from Smart-Phone User Logs

張錦生, Chang, Chin Sheng Unknown Date (has links)
資訊科技的進步與智慧型手機的普及,使得人們通訊方式改變,生活也更加依賴智慧型手機。然而,電池技術卻未能支援智慧型手機長時間使用,因此手機使用者在電量管理上的行為就變得相對重要。欲研究探討手機使用者的電量管理行為模式,須建立一個包含軟、硬體及使用者的實驗平台,本研究採用經麻省理工學院驗證的Funf Framework開放性原始碼框架,作為蒐集使用者操作紀錄資料,以情境假設觀察這些資料,定義出各情境行為模式的特徵,並根據實驗數據進行所有資料驗證。根據實驗結果,大致歸納出電量管理行為模式,此結果可提供使用者使用手機在電量管理上參考,或發展智慧型電量管理應用程式,以最佳化電量管理。 / The innovation of information technology and the spread of smart phones are changing the way that people communicate and how their livings rely on smart-phones. However, the technology of battery nowadays is still insufficient to meet the need of heavy smart-phones users; therefore, it be-comes relatively important to observe and analyze the user behavior on power management. This research aims to study the patterns of user be-havior on power management by building an experimental platform with appropriate software, hardware and users. We use the Funf Open Sensing Framework, which is originally developed at the MIT Media Lab, to collect user logs on smart phones. We have observed collected data under contex-tual assumptions, identified characteristics within the context of each be-havior pattern, and validated with the experimental data. With the result of the experiment, several patterns of power management have been classified. The experimental result can be used as a reference for the users to manage battery life, or for developing applications on smart power management that best optimizes energy consumption.

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