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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.
31

Dėžių pakavimo trimatėje erdvėje algoritmas ir jo taikymas logistikos uždaviniams spręsti / The algorithm of 3D bin packing and it application in logistics

Ražas, Artūras 31 May 2006 (has links)
Whether you are in industrial manufacturing striving to optimize your supply chain, international or domestic carrier committed to lower your operational costs, retailer dedicated to run your distribution network more efficiently, or anywhere else where the words "cargo", "freight", "shipment" are in your business language, automated load planning and optimization will significantly improve your business process. While the concept of computerized simulation of 3D load building is not new, with some companies offering software solutions for "virtual" loading, no one has a single product that is capable to handle complex variety of business rules and constraints of the modern transportation industry. We are analyzing the problems related with 3D box loading and then to analyze existing 3D load building systems. After accumulating all analyzes data we are having enough experience to create our own algorithm. And we did it! We create 3D box loading algorithm witch is fast and accurate and 3D box loading system which is using this new algorithm. To ensure that we succeeded we compare this new system with existing 3D box loading software to make sure that it’s really useful for solving logistic problems. After testing we are sure that we made a big job and we have created system, which can compete with the logistic IT leaders made solutions.
32

An analysis of the relative importance of institutional factors associated with plant location, with particular reference to meat packing plants

Blinka, Gary L. January 1966 (has links)
LD2668 .T4 1966 B648 / Master of Science
33

Capillary electrochromatography

Frame, Lesley A. January 2002 (has links)
No description available.
34

Applying meta-heuristic algorithms to the nesting problem utilising the no fit polygon

Kendall, Graham January 2000 (has links)
No description available.
35

Algorithmes pour des problèmes de bin packing mono- et multi-objectif / Algorithms for mono- and multi-objective bin packing problems

Khanafer, Ali 11 October 2010 (has links)
Le problème de bin packing consiste à déterminer le nombre minimum de conteneurs (bins) nécessaires pour ranger un ensemble d’objets. Ce problème NP- complet fait depuis de nombreuses années l’objet de multiples travaux de recherche, théoriques et pratiques. On le retrouve entre autres dans l’industrie de découpe de tissu, de l’acier, de bois et de verre. La littérature sur le problème de bin packing est riche et les algorithmes et approches de résolution sont très diverses. Cependant, les solutions proposées par ces algorithmes peuvent ne pas être utiles quand on traite des problèmes industriels réels. Dans cette thèse, nous considérons plusieurs types de contraintes liées à des incompatibilités entre objets. Ces contraintes sont inspirées de celles rencontrées lors d’une collaboration industrielle. Le sujet de recherche de cette thèse porte sur la résolution d’une variété de problèmes de bin packing. Nous nous intéressons à des bornes inférieures et supérieures pour les trois problèmes suivants : un problème de bin packing avec conflits dans lequel des relations de compatibilité sont exprimées entre les couples d’objets ; un problème de bin packing bi-objectif dans lequel deux critères sont à minimiser, le nombre de bins utilisés et le nombre de couples en conflit placés dans le même bin ; un problème de bin packing avec objets fragiles dans lequel la somme des tailles des objets placés dans un bin ne dépasse la fragilité d’aucun de ces objets. / The bin packing problem consists in minimizing the number of containers (bins) needed to place a set of objects. This NP-complete problem has been, for many years, the subject of multiple theoretical and practical researches. It appears in many industrial applications such as cutting steel, wood and glass. The literature on the bin packing problem is rich and the algorithms and resolution approaches are also very are very diversified. However, solutions offered by these algorithms may not be useful when we deal with real industrial problems. In this thesis, we consider several types of constraints such as compatibility relations between objects. These constraints are issued from real life industrial applications. The research topic of this thesis focuses on solving a variety of bin packing problems. We are interested in lower and upper bounds for three problems: a bin packing problem with conflicts in which some compatibility relations exist between pairs of objects, a problem bi-objective bin packing in which two criteria are to minimize: the number of bins used and the number of conflicting couples of objects placed in the same bin, a problem of bin packing with fragile objects in which the sum of the sizes of objects placed in a bin does not exceed the fragility of any of these objects.
36

Determining the Crystal Structure of Cellulose III by Modeling

Ford, Zakhia 10 August 2005 (has links)
Recently, a one-chain monoclinic unit cell for Cellulose IIII having a single glucose in the asymmetric unit was proposed based on high-resolution diffraction patterns. The new work challenged a two-chain structure published 25 years earlier, although it did not provide new three-dimensional coordinates. Our goals were to solve the structure by modeling, find whether modeling would reject the previously determined two-chain unit cell, and compare the model with the anticipated experimental structure. Combinations of the O2, O3, and O6 hydroxyls produced 54 starting structures. Clusters of 13 cellotetraose chains terminated by methyl groups for each of the 54 starting structures were optimized with MM3(96). Hydroxyl groups on 16 of these 54 structures reoriented to give very similar hydrogenbonding schemes in the interiors, along with the lowest energies. The one-chain cell models had much lower energy. The eight best “up” one-chain models agree well with the structure newly determined by experiment.
37

Academic Packing for Commercial FPGA Architectures

Haroldsen, Travis D. 01 July 2017 (has links)
With a few exceptions, academic packing algorithms for FPGAs are typically applied solely to theoretical architectures. This has allowed the algorithms to focus on the basic components of packing while abstracting away many of the details dictated by real hardware. As commercially available FPGAs have advanced, however, the academic algorithms and architectures have diverged significantly from their commercial counterparts. In this dissertation, the RapidSmith 2 framework is presented. This framework accurately reflects the architecture of Xilinx FPGAs and provides support for integrating custom tools into the commercial CAD tools. Using this framework, the RSVPack packing algorithm is implemented. The RSVPack algorithm can accept a design synthesized using the commercial Xilinx CAD tools, pack designs which make use of the many features of commercial FPGA architectures and return the packed designs to the Xilinx CAD tools to be placed and routed in their software. This enables researchers to isolate the packing portion of the algorithm from the commercial flow and evaluate different packing techniques while allowing the high-quality commercial tools to perform the remainder of the flow. Integrating the RSVPack algorithm the commercial flow shows RSVPack produces packing which lead to circuits with minimum clock periods within 10%, on average, of circuits generated using the pure Xilinx flow. Included in this work is a novel table lookup-based algorithm which RSVPack utilizes to quickly determine the routability of a cluster. This algorithm performs 5 times faster on average than the current academic alternatives. Finally, using RSVPack, this dissertation explores various techniques for improving the quality of packing for Xilinx circuits. Together, this demonstrates the potential for academic research into FPGA CAD tools for commercial architectures.
38

Bit-Packing Optimization for StreamIt

Agrawal, Kunal, Amarasinghe, Saman P., Wong, Weng Fai 01 1900 (has links)
StreamIt is a language specifically designed for modern streaming applications. A certain important class of these applications operates on streams of bits. This paper presents the motivation for a bit-packing optimization to be implemented in the StreamIt compiler for the RAW Architecture. This technique aims to pack bits into integers so that operations can be performed on multiple bits at once thus increasing the performance of these applications considerably. This paper gives some simple example applications to illustrate the various conditions where this technique can be applied and also analyses some of its limitations. / Singapore-MIT Alliance (SMA)
39

Circle Packings on Affine Tori

Sass, Christopher Thomas 01 August 2011 (has links)
This thesis is a study of circle packings for arbitrary combinatorial tori in the geometric setting of affine tori. Certain new tools needed for this study, such as face labels instead of the usual vertex labels, are described. It is shown that to each combinatorial torus there corresponds a two real parameter family of affine packing labels. A construction of circle packings for combinatorial fundamental domains from affine packing labels is given. It is demonstrated that such circle packings have two affine side-pairing maps, and also that these side-pairing maps depend continuously on the two real parameters.
40

Optimization methods for nesting problems

Timmerman, Mattijs January 2013 (has links)
Nesting problems have been present for as long as mankind exists. Present days these problems occur in many different industries, e.g. textile, paper, wood, metal and glass industry. These industries produce massive amounts of products to answer the global demand. To minimize the material waste making these products, a good cutting and packing layout is beneficial. The last three decades, researchers have focused on developing methods to solve these problems through computing, instead of solving them manually. Many possible solutions have been found, each method focusing on the specifications of the problem. This thesis had two sub-objectives. The first one was to find the best method for nesting optimization, by doing an intensive literature study. The second sub-objective was to work with a previous made program that is capable of doing optimization tests, containing a nesting optimization method, and try to improve this method to get better results, using the literature study. At a certain point in this project, based on the progress of the literature study and knowledge acquired on the in-house developed program, a decision had to be made either to continue with the previous developed method or to try a new method. A lot of ideas from the literature where used and implemented to improve the method leading to improving results. Hence, the choice was made to continue working with the previous developed method. A new placement strategy was introduced in the program. Additional program code to improve stencil evaluation was added. A proper user interface was created. At the end of this project, a nesting optimization method was obtained, capable of producing a feasible solution when solving a nesting problem, within a reasonable amount of time.

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