Дисертації з теми "Coordinated method"
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1
Thepparat, Pakorn. "Analysis of the combined and coordinated control method for HVDC transmission." Aachen Shaker, 2010. http://d-nb.info/1001789059/04.
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2
Thepparat, Pakorn [Verfasser]. "Analysis of the Combined and Coordinated Control Method for HVDC Transmission / Pakorn Thepparat." Aachen : Shaker, 2010. http://d-nb.info/1122546165/34.
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3
[Verfasser], Pakorn Thepparat. "Analysis of the Combined and Coordinated Control Method for HVDC Transmission / Pakorn Thepparat." Aachen : Shaker, 2010. http://nbn-resolving.de/urn:nbn:de:101:1-201701012279.
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4
Striley, Catherine M. "A Multiple Method Longitudinal Study of Gifted Adolescents’ Communication of and about Ostracism and Social Exclusion." Ohio University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1417725012.
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5
Chen, Guodong. "Solution of diffusion equation in axisymmetrical coordinates." Ohio : Ohio University, 1994. http://www.ohiolink.edu/etd/view.cgi?ohiou1176840295.
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6
ANGELOCCI, LUCAS V. "Estudo de casos clínicos em radioterapia através do sistema de planejamento AMIGOBrachy." reponame:Repositório Institucional do IPEN, 2016. http://repositorio.ipen.br:8080/xmlui/handle/123456789/26926.
Повний текст джерелаАнотація:
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O sucesso de uma radioterapia depende do correto planejamento da dose a ser entregue ao volume alvo. Na braquiterapia, modalidade da radioterapia onde um radioisótopo selado é implantado intracavitariamente ou intersticialmente no paciente, há menos avanços em sistemas de planejamento de tratamento computacionais do que na teleterapia, amplamente mais utilizada nos serviços típicos. Porém, a braquiterapia, quando aplicável, é preferível por poupar tecidos sadios vizinhos de uma dose desnecessária. O AMIGOBrachy, um sistema de planejamento para braquiterapia de interface amigável, compatibilidade com outros sistemas comerciais em uso e integrado ao código MCNP6 (Monte Carlo N-Particle Transport Code v. 6) foi desenvolvido no Centro de Engenharia Nuclear do Instituto de Pesquisas Energéticas e Nucleares (CEN-IPEN) e atualmente está em processo de validação. Este trabalho contribuiu para este processo, avaliando três diferentes casos clínicos através do AMIGOBrachy com o formalismo do TG43 da AAPM (Associação Americana de Física Médica), protocolo que rege a dosimetria em braquiterapia, e comparando seus resultados com as distribuições de dose calculadas por outros sistemas comerciais consagrados: Varian BrachyVision TM (Varian Medical Systems; Palo Alto, CA, EUA) e Nucletron Oncentra® (Elekta; Estocolmo, Suécia). Os resultados obtidos estão dentro de uma faixa de concordância de ±10%, estando mais discrepantes em regiões muito próximas do aplicador, onde os sistemas de planejamento comerciais e o AMIGOBrachy divergem devido aos diferentes métodos de cálculo. Em pelo menos dois terços da região de interesse, porém, a dose concordou em uma faixa de ±3% para os três casos. Também foram realizadas simulações utilizando o formalismo do TG186 da AAPM, que considera heterogeneidades no tecido, para avaliar o impacto dos mesmos na dose. Em adição ao processo de validação, também foi realizado um estudo em braquiterapia oftálmica para posterior inserção de um módulo adicional ao AMIGOBrachy; para isso, um modelo de olho humano foi desenvolvido utilizando geometria UM (Unstructured Mesh), para validação com o código MCNP6, que apenas nesta versão demonstra um novo recurso capaz de simular uma geometria híbrida: parcialmente analítica, parcialmente UM. O modelo considera dez diferentes estruturas no olho humano: esclera, coroide, retina, corpo vítreo, córnea, câmara anterior, lente, nervo óptico, parede do nervo óptico, e um tumor definido de forma arbitrária crescendo da superfície externa do globo ocular em direção ao seu centro. Os resultados foram comparados com um modelo de olho puramente analítico modelado com o MCNP6 e tomado como referência. Os resultados foram satisfatórios em todas as simulações desenvolvidas, exceto para as estruturas do nervo óptico e sua parede, que devido ao seu pequeno tamanho e distância da fonte, mostraram erros relativos maiores, mas ainda menores que 10%, e não representam problema de preocupação clínica uma vez que recebem doses muito pequenas. Discutiu-se também a eficácia e problemas encontrados nessa nova capacidade do código MCNP de simular geometrias híbridas, uma vez que é recente e ainda apresenta deficiências, que tiveram que ser contornadas no presente trabalho.
Dissertação (Mestrado em Tecnologia Nuclear)
IPEN/D
Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
7
區榮海 and Wing-hoi Au. "Numerical generation of body-fitted coordinates by multigrid method." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1990. http://hub.hku.hk/bib/B31209555.
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Au, Wing-hoi. "Numerical generation of body-fitted coordinates by multigrid method /." [Hong Kong] : University of Hong Kong, 1990. http://sunzi.lib.hku.hk/hkuto/record.jsp?B1296637X.
Повний текст джерела
9
Mund, F. C. "Coordinated application of CFD and gas turbine performance methods." Thesis, Cranfield University, 2006. http://dspace.lib.cranfield.ac.uk/handle/1826/10571.
Повний текст джерелаАнотація:
In conventional
gas turbine performance methods, components are represented
by characteristics where the 3d properties of the flow fields' are averaged providing key flow properties at component interfaces. For the design of a component,
the consideration of the 3d nature of the flow is crucial and Computational Fluid
Dynamics (CFD) is well established in the design process; however computational
challenges generally limit the application to individual components only. The fact
that each
engine component has an effect on the overall engine performance sets
a
strong incentive to link the two methods closer together. This thesis explores
the
potential benefits of the 'coordinated application of performance modelling
and CFD
through two proof-of-concept case studies.
The, research context of the first case study was high fidelity performance simulation.
A
performance simulation process With a 2d radial representation of the
low
pressure system has been developed for a high bypass turbofan. The intake
and
bypass section were represented using axial-symmetric 2d CFD modules and
radial flow
profiles were exchanged at the component interfaces to an existing 2d
radial fan model. The iteration
procedure between the two tools was performed
manually and investigated for various operating conditions. A match of the flow
data between the tools was achieved for the intake. Guidance for improvements
and an automation of the
process are also given.
The research of the second case
study involved the design of component subsystems
in an industrial application and illustrates the potential of using CFD and
performance simulation for the design of a compressor washing system; The optimisation
of a
compressor washing system for an industrial gas turbine has been
studied
using a 3d CFD model of the intake component. Due to the interaction of
droplets with the surrounding air flow, the key factors from injection system and'
the air flow demand of the
gas turbine were investigated. Boundary conditions
were
provided using a performance simulation tool which facilitated the evaluation
of relevant
operating conditions. Associated spray parameters were derived
from numerical
sensitivity studies calibrated to data from visual field inspections
and
key design parameters were provided. Improvements were suggested and
confirmed for a similar field installation. ~
10
Mund, Friederike C. "Coordinated application of CFD and gas turbine performance methods." Thesis, Cranfield University, 2006. http://dspace.lib.cranfield.ac.uk/handle/1826/10571.
Повний текст джерелаАнотація:
In conventional gas turbine performance methods, components are represented by characteristics where the 3d properties of the flow fields' are averaged providing key flow properties at component interfaces. For the design of a component, the consideration of the 3d nature of the flow is crucial and Computational Fluid Dynamics (CFD) is well established in the design process; however computational challenges generally limit the application to individual components only. The fact that each engine component has an effect on the overall engine performance sets a strong incentive to link the two methods closer together. This thesis explores the potential benefits of the 'coordinated application of performance modelling and CFD through two proof-of-concept case studies. The, research context of the first case study was high fidelity performance simulation. A performance simulation process With a 2d radial representation of the low pressure system has been developed for a high bypass turbofan. The intake and bypass section were represented using axial-symmetric 2d CFD modules and radial flow profiles were exchanged at the component interfaces to an existing 2d radial fan model. The iteration procedure between the two tools was performed manually and investigated for various operating conditions. A match of the flow data between the tools was achieved for the intake. Guidance for improvements and an automation of the process are also given. The research of the second case study involved the design of component subsystems in an industrial application and illustrates the potential of using CFD and performance simulation for the design of a compressor washing system; The optimisation of a compressor washing system for an industrial gas turbine has been studied using a 3d CFD model of the intake component. Due to the interaction of droplets with the surrounding air flow, the key factors from injection system and' the air flow demand of the gas turbine were investigated. Boundary conditions were provided using a performance simulation tool which facilitated the evaluation of relevant operating conditions. Associated spray parameters were derived from numerical sensitivity studies calibrated to data from visual field inspections and key design parameters were provided. Improvements were suggested and confirmed for a similar field installation.
11
Yun, Sangwoon. "A coordinate gradient descent method for structured nonsmooth optimization /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/5738.
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12
Takac, Martin. "Randomized coordinate descent methods for big data optimization." Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/9670.
Повний текст джерелаАнотація:
This thesis consists of 5 chapters. We develop new serial (Chapter 2), parallel (Chapter 3), distributed (Chapter 4) and primal-dual (Chapter 5) stochastic (randomized) coordinate descent methods, analyze their complexity and conduct numerical experiments on synthetic and real data of huge sizes (GBs/TBs of data, millions/billions of variables). In Chapter 2 we develop a randomized coordinate descent method for minimizing the sum of a smooth and a simple nonsmooth separable convex function and prove that it obtains an ε-accurate solution with probability at least 1 - p in at most O((n/ε) log(1/p)) iterations, where n is the number of blocks. This extends recent results of Nesterov [43], which cover the smooth case, to composite minimization, while at the same time improving the complexity by the factor of 4 and removing ε from the logarithmic term. More importantly, in contrast with the aforementioned work in which the author achieves the results by applying the method to a regularized version of the objective function with an unknown scaling factor, we show that this is not necessary, thus achieving first true iteration complexity bounds. For strongly convex functions the method converges linearly. In the smooth case we also allow for arbitrary probability vectors and non-Euclidean norms. Our analysis is also much simpler. In Chapter 3 we show that the randomized coordinate descent method developed in Chapter 2 can be accelerated by parallelization. The speedup, as compared to the serial method, and referring to the number of iterations needed to approximately solve the problem with high probability, is equal to the product of the number of processors and a natural and easily computable measure of separability of the smooth component of the objective function. In the worst case, when no degree of separability is present, there is no speedup; in the best case, when the problem is separable, the speedup is equal to the number of processors. Our analysis also works in the mode when the number of coordinates being updated at each iteration is random, which allows for modeling situations with variable (busy or unreliable) number of processors. We demonstrate numerically that the algorithm is able to solve huge-scale l1-regularized least squares problems with a billion variables. In Chapter 4 we extended coordinate descent into a distributed environment. We initially partition the coordinates (features or examples, based on the problem formulation) and assign each partition to a different node of a cluster. At every iteration, each node picks a random subset of the coordinates from those it owns, independently from the other computers, and in parallel computes and applies updates to the selected coordinates based on a simple closed-form formula. We give bounds on the number of iterations sufficient to approximately solve the problem with high probability, and show how it depends on the data and on the partitioning. We perform numerical experiments with a LASSO instance described by a 3TB matrix. Finally, in Chapter 5, we address the issue of using mini-batches in stochastic optimization of Support Vector Machines (SVMs). We show that the same quantity, the spectral norm of the data, controls the parallelization speedup obtained for both primal stochastic subgradient descent (SGD) and stochastic dual coordinate ascent (SCDA) methods and use it to derive novel variants of mini-batched (parallel) SDCA. Our guarantees for both methods are expressed in terms of the original nonsmooth primal problem based on the hinge-loss. Our results in Chapters 2 and 3 are cast for blocks (groups of coordinates) instead of coordinates, and hence the methods are better described as block coordinate descent methods. While the results in Chapters 4 and 5 are not formulated for blocks, they can be extended to this setting.
13
de, Tenorio Cyril. "Methods for collaborative conceptual design of aircraft power architectures." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34818.
Повний текст джерелаАнотація:
This thesis proposes an advanced architecting methodology. This methodology allows for the sizing and optimization of aircraft system architecture concepts and the establishment of subsystem development strategies. The process is implemented by an architecting team composed of subsystem experts and architects. The methodology organizes the architecture definition using the SysML language. Using meta-modeling techniques, this definition is translated into an analysis model which automatically integrates subsystem analyses in a fashion that represents the specific architecture concept described by the team. The resulting analysis automatically sizes the subsystems composing it, synthesizes their information to derive architecture-level performance and explores the architecture internal trade-offs. This process is facilitated using the Coordinated Optimization method proposed in this dissertation. This method proposes a multi-level optimization setup. An architecture-level optimizer orchestrates the subsystem sizing optimizations in order to optimize the aircraft as whole. The methodologies proposed in this thesis are tested and demonstrated on a proof of concept based on the exploration of turbo-electric propulsion aircraft concepts.
14
Daskilewicz, Matthew John. "Methods for parameterizing and exploring Pareto frontiers using barycentric coordinates." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/47658.
Повний текст джерелаАнотація:
The research objective of this dissertation is to create and demonstrate methods for parameterizing the Pareto frontiers of continuous multi-attribute design problems using barycentric coordinates, and in doing so, to enable intuitive exploration of optimal trade spaces. This work is enabled by two observations about Pareto frontiers that have not been previously addressed in the engineering design literature. First, the observation that the mapping between non-dominated designs and Pareto efficient response vectors is a bijection almost everywhere suggests that points on the Pareto frontier can be inverted to find their corresponding design variable vectors. Second, the observation that certain common classes of Pareto frontiers are topologically equivalent to simplices suggests that a barycentric coordinate system will be more useful for parameterizing the frontier than the Cartesian coordinate systems typically used to parameterize the design and objective spaces.
By defining such a coordinate system, the design problem may be reformulated from y = f(x) to (y,x) = g(p) where x is a vector of design variables, y is a vector of attributes and p is a vector of barycentric coordinates. Exploration of the design problem using p as the independent variables has the following desirable properties: 1) Every vector p corresponds to a particular Pareto efficient design, and every Pareto efficient design corresponds to a particular vector p. 2) The number of p-coordinates is equal to the number of attributes regardless of the number of design variables. 3) Each attribute y_i has a corresponding coordinate p_i such that increasing the value of p_i corresponds to a motion along the Pareto frontier that improves y_i monotonically.
The primary contribution of this work is the development of three methods for forming a barycentric coordinate system on the Pareto frontier, two of which are entirely original. The first method, named "non-domination level coordinates," constructs a coordinate system based on the (k-1)-attribute non-domination levels of a discretely sampled Pareto frontier. The second method is based on a modification to an existing "normal boundary intersection" multi-objective optimizer that adaptively redistributes its search basepoints in order to sample from the entire frontier uniformly. The weights associated with each basepoint can then serve as a coordinate system on the frontier. The third method, named "Pareto simplex self-organizing maps" uses a modified a self-organizing map training algorithm with a barycentric-grid node topology to iteratively conform a coordinate grid to the sampled Pareto frontier.
15
Somthong, Thammarat. "3D freeform surface measurement on coordinate measuring machine using photometric stereo method." Thesis, Brunel University, 2017. http://bura.brunel.ac.uk/handle/2438/15270.
Повний текст джерелаАнотація:
Surface metrology has been widely used in manufacturing for many years. There has been a wide range of techniques applied for measuring surface topography. A photometric stereo technique is one of the best ways for the analysis of three-dimensional (3D) surface textural patterns. Many published works are concerned the developed approach for recovering the 3D profiles from surface normal. This research not only presents a methodology used to retrieve the profiles of surface roughness standards but also investigates the uncertainty estimation of textural measurement determined by the photometric stereo method. Various input quantities have been studied such as pixel error from recovered 3D surface textural patterns, the power of light source which involved with surface roughness average (Ra) value and the effect of room temperature. The surface roughness standards were utilized as the reference value. In term of increasing accuracy of the reference value, a contact method (stylus instrument) was used to calibrate them. Illumination angles of light source had some influence on the measurement results. A coordinate measuring machine (CMM) was used for holding the light source in order to study the effects of tilt and slant angles. The effect of tilt and slant angles were investigated. The results of these experiments successfully indicated that the angle used in photometric stereo method played an important role to the accuracy level of the roughness measurement results. The surface roughness specimen manufactured by a Computer Numerical Control (CNC) was applied to validate the capability of the photometric stereo system.
16
Pendse, Nachiket Vishwas. "An effective dimensional inspection method based on zone fitting." Texas A&M University, 2004. http://hdl.handle.net/1969.1/3239.
Повний текст джерелаАнотація:
Coordinate measuring machines are widely used to generate data points from an actual surface. The generated measurement data must be analyzed to yield critical geometric deviations of the measured part according to the requirements specified by the designer. However, ANSI standards do not specify the methods that should be used to evaluate the tolerances. The coordinate measuring machines employ different verification algorithms which may yield different results. Functional requirements or assembly conditions on a manufactured part are normally translated into geometric constraints to which the part must conform. Minimum zone evaluation technique is used when the measured data is regarded as an exact copy of the actual surface and the tolerance zone is represented as geometric constraints on the data.
In the present study, a new zone-fitting algorithm is proposed. The algorithm evaluates the minimum zone that encompasses the set of measured points from the actual surface. The search for the rigid body transformation that places the set of points in the zone is modeled as a nonlinear optimization problem. The algorithm is employed to find the form tolerance of 2-D (line, circle) as well as 3-D geometries (cylinder). It is also used to propose an inspection methodology for turbine blades. By constraining the transformation parameters, the proposed methodology determines whether the points measured at the 2-D cross-sections fit in the corresponding tolerance zones simultaneously.
17
Міхненко, Ярослав Олександрович. "Модифікований метод передачі даних в мережі Інтернету Речей". Master's thesis, КПІ ім. Ігоря Сікорського, 2021. https://ela.kpi.ua/handle/123456789/42139.
Повний текст джерелаАнотація:
Робота містить 70 сторінок, 15 рисунків, та 10 таблиць. Було використано 35 джерел.
Мета роботи: підвищити енергоефективність сенсорної мережі IoT за рахунок модифікації методу передачі інформації, що дозволить збільшити час роботи вузлів збору та передачі інформації сенсорної мережі IoT.
Проведено детальний аналіз проблем Інтернету речей, особливу увагу було звернено на питання модернізації архітектури мережі задля підвищення енергоефективності та збільшення терміну служби мережі. Детально розібрано метод випадкового циклу Sleep/Wake. Поставлено та виконано завдання модифікації архітектури бездротової сенсорної мережі Інтернету речей. Запропоновано координований метод циклу Sleep/Wake для передачі пакетів інформації в межах сенсорної мережі Інтернету речей. Після проведення оцінки нового методу та його імітаційного моделювання, було зроблено висновок, що такий модифікований метод може бути корисним для впровадження, оскільки:
1. Життєвий цикл мережі за допомогою запропонованого координованого методу обчислення робочого циклу та визначення черг збільшився від 3,8% до 11,25%.
2. Збільшився термін служби сенсорної мережі в порівнянні з асинхронним циклом черг в сенсорних мережах Інтернету речей від 8,4% до 14,8%.The thesis contains 70 pages, 15 figures, and 10 tables. 35 sources have been used. The purpose of the work is to increase the energy efficiency of the IoT sensor network by modifying the method of information transmission, which will increase the operating time of the nodes of collection and transmission of information of the IoT sensor network. The detailed analysis of the problems of the Internet of Things has been made. Special attention has been paid to modernizing the architecture of the network for improving its energy efficiency and extending its lifetime. The method of random Sleep/Wake cycle has been analyzed in detail. The task to modify the architecture of the wireless sensorу network of the Internet of Things has been fulfilled. The co-ordinated Sleep/Wake cycle method is proposed for transmitting information packets within the sensory network of the Internet of Things. After evaluating the new method and its simulation model, it was concluded that this modified method might be useful for implementation, since: 1. The life cycle of the network with the proposed coordinated method for calculating the duty cycle and queue determination increased from 3.8% to 11.25%. 2. The lifetime of the sensory network increased from 8.4% to 14.8%, compared to the asynchronous cycle of queues in the sensory networks of the Internet of Things.
18
PIRES, LUIS FERNANDO GONCALVES. "A NUMERICAL METHOD FOR SOLVING FLOWS USING COVARIANT COMPONENTS IN NON-ORTHOGONAL COORDINATES." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1994. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=18621@1.
Повний текст джерелаАнотація:
PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
O trabalho desenvolveu uma metodologia de solução numérica de escoamentos em geometrias complexas, numa formulação incompressível e bi-dimensional. As equações de conservação são discretizas com o emprego da técnica de volumes finitos em coordenadas não ortogonais. Esta técnica mapeia o espaço real num espaço transformado, no qual as fronteiras do domínio de cálculo coincidem com as fronteiras do domínio físico. Os componentes contravariantes da velocidade foram empregados como variáveis dependentes nas equações de conservação de quantidade de movimento. Estas equações foram obtidas em coordenadas não ortogonais pela manipulação algébrica das equações discretizadas para os componentes cartesianos. Este procedimento, que emprega um sistema de coordenadas auxiliar fixo localmente, evita o surgimento dos diversos termos oriundos da curvutura e da não ortogonalidade da malha, que seriam obtidos caso fosse empregada a análise tensorial para a derivação destas equações. O ocoplamento pressão-velocidade é feito utilizando SIMPLEC. O conjunto de equações algébricas resultante é resolvido por um esquema de solução segregado, no qual é empregado um esquema de solução linha-a-a linha(TDMA), com um processo de correção por blocos para acelerar a convergência. A metodologia desenvolvida foi utilizada para solução de diversos problemas visando analisar o seu desempenho. Foram estudados os seguintes casos-escoamento laminar entre dois cilindros, convecção natural entre dois cilidros excêntricos, escoamento induzido numa cavidade trapezoidal pelo movimento de suas bases, escoamento laminar num canal, escoamento axi-simétrico num duto com estrangulamento.Tendo em vista os bons resultados obtidos para testes, pode-se concluir que as opções realizadas para a confeção do esquema desenvolvido foram corretas, pois geraram um algoritimo efeciente e versátil.
A solution method for bi-dimensional incompressibible fluid flow problems in complex geometrics is developed in this work. The method solves the conservation equations in nonorthogonal coordinate system using the finite volumes technique. The contravariant velocities are kept as dependent variables in the momentum equations. These equations are obtained by an algebric manipulation of the discretization equations written in locally fixed coordinate system. This producedure avoids the treatment of the extra terms if the discretization equations for the curvilinear velocities are obtained in the conventional manner. The coupling of pressure and velocities are performed by the SIMPLEC algorithm. The set of algebric equations are solved using an iterative method in conjunction with coefficient update for linerization. In the computer implementation of the proposed scheme a line-by-line algorithm (TDMA) has been employed with a block corretion procedure to enhance the convergence. The method is tested by solving a variety of problems. The problems include-flow between two concentric rotating cylinders, natural convection in an eccentric annuli, driven flow in a trapezoidal cavity with moving lids, laminar flow in a channel, exismetric flow in duct with reduced cross section and laminar and turbulent flow through a tube with an axisimetric constriction. The objetive of these tests is to establish the validity of the proposed scheme and demonstrate its applicability to a wide variety of problems.
19
Hu, Yang. "Investigation and development of an advanced virtual coordinate measuring machine." Thesis, Brunel University, 2010. http://bura.brunel.ac.uk/handle/2438/7507.
Повний текст джерелаАнотація:
Dimensional measurement plays a critical role in product development and quality control. With the continuously increasing demand for tighter tolerances and more complex workpiece shapes in the industry, dimensional metrology often becomes the bottleneck of taking the quality and performance of manufacturing to the next level. As one kind of the most useful and powerful measuring instruments, coordinate measuring machines (CMMs) are widely employed in manufacturing industries. Since the accuracy and efficiency of a CMM have a vital impact on the product quality, productivity and manufacturing cost, the evaluation and improvement of CMM performance have always been important research topics since the invention of CMM. A novel Advanced Virtual Coordinate Measuring Machine (AVCMM) is proposed against such a background. The proposed AVCMM is a software package that provides an integrated virtual environment, in which user can plan inspection strategy for a given task, carry out virtual measurement, and evaluate the uncertainty associated with the measurement result, all without the need of using a physical machine. The obtained estimate of uncertainty can serve as a rapid feedback for user to optimize the inspection plan in the AVCMM before actual measurement, or as an evaluation of the result of a performed measurement. Without involving a physical CMM in the inspection planning or evaluation of uncertainty, the AVCMM can greatly reduce the time and cost needed for such processes. Furthermore, as the package offers vivid 3D visual representation of the virtual environment and supports operations similar to a physical CMM, it does not only allow the user to easily plan and optimise the inspection strategy, but also provide a cost-effective, risk-free solution for training CMM operators. A modular, multitier architecture has been adopted to develop the AVCMM system, which incorporates a number of functional components covering CMM and workpiece modelling, error simulation, inspection simulation, feature calculation, uncertainty evaluation and 3D representation. A new engine for detecting collision/contact has been developed and utilized, which is suitable for the virtual environment of simulated CMM inspections. A novel approach has been established to calculate errors required for the error simulation, where the data are obtained from FEA simulations in addition to conventional experimental method. Monte Carlo method has been adopted for uncertainty evaluation and has been implemented with multiple options available to meet different requirements. A prototype of the proposed AVCMM system has been developed in this research. Its validity, usability and performance have been verified and evaluated through a set of experiments. The principles for utilising the AVCMM in practical use have also been established and demonstrated. The results have indicated that the proposed AVCMM system has great potentials to improve the functionalities and overall performance of CMMs.
20
Ternsjö, Simon. "Optimization of routine to find the correct zone for GPS coordinates." Thesis, Uppsala universitet, Institutionen för informationsteknologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-210605.
Повний текст джерелаАнотація:
In this thesis a logistics program for keeping track of delivery cars was developed. The program was developed for Jetpak, a logistics company and customer of the IT consulting company Softronic where this thesis work was preformed. Jetpak has divided Sweden into areas called ''trafikledningszoner'' (TLZs) which are used to direct the most suitable car for a new delivery. The aim was to improve Jetpaks current system for keeping track of their cars by increasing the speed at which the cars' TLZs are tracked as well as by visualising the TLZs on a map and make them editable. Two programs were developed to perform this task. The look up program uses the crossing method to calculate in what TLZ each car is in using its GPS coordinates. The editing program displays and enables editing of TLZs on a Google map. This work has resulted in the possibility of a greater understanding of the exact layout of the TLZs as well as a possibility to edit them to better suit Jetpaks needs. This is an improvement over the current system because more understanding and more control is given to Jetpak. However, these programs can still be improved to ease the editing process by adding more usable functionality.
21
Hua, Xiaoqin. "Studies on block coordinate gradient methods for nonlinear optimization problems with separable structure." 京都大学 (Kyoto University), 2015. http://hdl.handle.net/2433/199447.
Повний текст джерела
22
Kuhlman, Kristopher Lee. "Laplace Transform Analytic Element Method for Transient Groundwater Flow Simulation." Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/193735.
Повний текст джерелаАнотація:
The Laplace transform analytic element method (LT-AEM), applies the traditionally steady-state analytic element method (AEM) to the Laplace-transformed diffusion equation (Furman and Neuman, 2003). This strategy preserves the accuracy and elegance of the AEM while extending the method to transient phenomena. The approach taken here utilizes eigenfunction expansion to derive analytic solutions to the modified Helmholtz equation, then back-transforms the LT-AEM results with a numerical inverse Laplace transform algorithm. The two-dimensional elements derived here include the point, circle, line segment, ellipse, and infinite line, corresponding to polar, elliptical and Cartesian coordinates. Each element is derived for the simplest useful case, an impulse response due to a confined, transient, single-aquifer source. The extension of these elements to include effects due to leaky, unconfined, multi-aquifer, wellbore storage, and inertia is shown for a few simple elements (point and line), with ready extension to other elements. General temporal behavior is achieved using convolution between these impulse and general time functions; convolution allows the spatial and temporal components of an element to be handled independently.Comparisons are made between inverse Laplace transform algorithms; the accelerated Fourier series approach of de Hoog et al. (1982) is found to be the most appropriate for LT-AEM applications. An application and synthetic examples are shown for several illustrative forward and parameter estimation simulations to illustrate LT-AEM capabilities. Extension of LT-AEM to three-dimensional flow and non-linear infiltration are discussed.
23
Garza-Delgado, Abelardo. "A study of casting distortion and residual stresses in die casting." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1196175848.
Повний текст джерела
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Tråsdahl, Øystein. "High order methods for partial differential equations: geometry representation and coordinate transformations." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for matematiske fag, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-17077.
Повний текст джерела
25
Lehmann, Rüdiger. "Ein automatisches Verfahren für geodätische Berechnungen." Hochschule für Technik und Wirtschaft Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:520-qucosa-188715.
Повний текст джерелаАнотація:
Dieses Manuskript entstand aus Vorlesungen über Geodätische Berechnungen an der Hochschule für Technik und Wirtschaft Dresden. Da diese Lehrveranstaltung im ersten oder zweiten Semester stattfindet, werden noch keine Methoden der höheren Mathematik benutzt. Das Themenspektrum beschränkt sich deshalb weitgehend auf elementare Berechnungen in der Ebene. Nur im Kapitel 7 kommen einige Methoden der
Vektorrechnung zum Einsatz.
26
Чернова, О., та А. І. Азаренкова. "Векторно-координатний метод розв’язання задач". Thesis, Видавництво СумДУ, 2009. http://essuir.sumdu.edu.ua/handle/123456789/13392.
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Peres, Noele. "A 3D pseudospectral method for cylindrical coordinates. Application to the simulations of rotating cavity flows." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM4309/document.
Повний текст джерелаАнотація:
La simulation d'écoulements dans des cavités cylindriques en rotation présente une difficulté particulière en raison de l'apparition de singularités sur l'axe. Le présent travail propose une méthode collocative pseudospectrale suffisamment efficace et précise pour surmonter cette difficulté et résoudre les équations 3D de Navier-Stokes écrites en coordonnées cylindriques. Cette méthode a été développée dans le cadre des différentes études menées au laboratoire M2P2, utilisant une méthode collocative de type Chebychev dans les directions radiale et axiale et Fourier-Galerkin dans la direction azimutale [thêta]. Pour éviter de prescrire des conditions sur l'axe, une nouvelle approche a été développée. Le domaine de calcul est défini par (r,[thêta],z)∈[-1,1]×[0,2π]×[-1,1] avec un nombre N pair de points de collocation dans la direction radiale. Ainsi, r=0 n'est pas un point de collocation. La distribution de points de type Gauss-Lobatto selon r et z densifie le maillage seulement près des parois ce qui rend l'algorithme bien adapté pour simuler les écoulements dans des cavités cylindriques en rotation. Dans la direction azimutale, le chevauchement des points dû à la discrétisation est évitée par l'introduction d'un décalage égal à π/2K à [thêta]>π dans la transformée de Fourier. La méthode conserve la convergence spectrale. Des comparaisons avec des résultats expérimentaux et numériques de la littérature montrent un très bon accord pour des écoulements induits par la rotation d'un disque dans des cavités cylindriques ferméesWhen simulating flows in cylindrical rotating cavities, a difficulty arises from the singularities appearing on the axis. In the same time, the flow field itself does not have any singularity on the axis and this singularity is only apparent. The present work proposes an efficient and accurate collocation pseudospectral method for solving the 3D Navier-Stokes equations using cylindrical coordinates. This method has been developed in the framework of different studies of rotor-stator flows, using Chebyshev collocation in the radial and axial directions and Fourier-Galerkin approximation in the azimuthal periodic direction [thêta]. To avoid the difficulty on the axis without prescribing any pole and parity conditions usually required, a new approach has been developed. The calculation domain is defined as (r,[thêta];,z)∈[-1,1]×[0,2π]×[-1,1] using an even number N of collocation points in the radial direction. Thus, r=0 is not a collocation point. The method keeps the spectral convergence. The grid-point distribution densifies the mesh only near the boundaries that makes the algorithm well-suited to simulate rotating cavity flows where thin layers develop along the walls. In the azimuthal direction, the overlap in the discretization is avoided by introducing a shift equal to π/2K for [thêta]>π in the Fourier transform. Comparisons with reliable experimental and numerical results of the literature show good quantitative agreements for flows driven by rotating discs in cylindrical cavities. Associated to a Spectral Vanishing Viscosity, the method provides very promising LES results of turbulent cavity flows with or without heat transfer
28
Pierce, Janine E. (Janine Elizabeth) 1980. "Coordinate system dependence of muscle forces predicted using optimization methods in musculoskeletal joints." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/27119.
Повний текст джерелаАнотація:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004.Includes bibliographical references (p. 143-147).
Optimization methods are widely used to predict in-vivo muscle forces in musculoskeletal joints. Moment equilibrium at the joint center (usually defined as the origin of the joint coordinate system) has been used as a constraint condition for optimization procedures and the joint reaction moments were assumed to be zero. This research project, through the use of a three-dimensional elbow model, investigated the effect of joint center location on muscle forces predicted using a nonlinear static optimization method. The results demonstrated that moving the joint center medially and laterally along the flexion-extension axis caused dramatic variations in the predicted muscle forces. For example, moving the joint center from a position 5 mm medial to 5 mm lateral of the geometric elbow center caused the predicted biceps force to vary from 12% to 46% and the brachialis force to vary from 80% to 34% of the total muscle loading. The joint reaction force reduced by 24% with this medial to lateral variation of the joint center location. This data revealed that the muscle forces predicted using optimization methods are sensitive to the joint center location due to the zero joint reaction moment assumption in the moment constraint condition. For accurate prediction of muscle load distributions using optimization methods, it is necessary to determine the true joint center location where the condition of a zero joint reaction moment is satisfied. Furthermore, improvements to the current optimization methodology were suggested. Incorporation of the 3D joint center location, as three unknown variables, into the optimization program was proposed, and this procedure was investigated for a pilot case incorporating one of the joint center components (y-axis variable) into the optimization.
(cont.) This thesis work indicates that all previously published data on muscle and joint loads predicted via optimization methods should be revisited since the joint reaction moment was eliminated in those works.
by Janine E. Pierce.
S.M.
29
Tuzun, Aydin. "Large Deformation Analysis Of Flexible Multibody Systems." Phd thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614821/index.pdf.
Повний текст джерелаАнотація:
Large displacement and large strain problems of mechanical systems can be solved mainly by four methods. These are Floating Frame of Reference, Incremental Finite Element, Large Rotation Vector and Absolute Nodal Coordinate Formulations (ANCF). Due to exact rigid body representation, simple mass matrix structure and non-incremental formulation, ANCF is more convenient in analyzing flexible multibody systems. However, it is limited to problems with regular boundaries, currently.
The aim of the thesis is to improve the current ANCF in order to handle various problems with irregular boundaries. For this purpose, firstly meshfree ANCF has been developed to analyze flexible multibody systems. Verification of the developed meshfree formulation has been performed for beam type structures and accurate results have been obtained. Then, &ldquoANCF with Virtual Element Mapping Method&rdquo
has been proposed to overcome the boundary problems of the current formulations. The proposed method has been implemented to plane stress, plane strain, plate/shell and 3D solid finite elements. Verification of the proposed method has been performed by using the patch test problems available in the literature. Besides, it has been verified by various flexible multibody problems with large deformations. Additionally, shape function polynomials for thin plate assumption have been derived. It is observed that developed formulations and methods can be useful not only for flexible multibody systems but also for structural mechanics problems subjected to large deformations and/or rotations. The proposed methods and formulations are more efficient than the current formulations in the literature due to extended shape limits of finite elements.
30
Fossum, Heidi. "Coordinated freight logistics in existing city districts- Evaluation of methods for calculating energy and environmental effects." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-84166.
Повний текст джерелаАнотація:
Norra Djurgårdsstaden is the largest ongoing construction project in Sweden and is planned to be completed in 2030. The city district is situated in north-eastern Stockholm, in a former industrial area where approximately 12 000 new homes and 35 000 workplaces are planned. The city district focuses strongly on reducing energy consumption and the negative impacts on the environment. One idea for realizing this goal is to implement coordinated freight logistics. This can be accomplished by building a consolidation centre where goods from different logistics companies and freight carriers can be loaded together on the same delivery vehicles and then be delivered in the same area in Norra Djurgårdsstaden. The purpose of this master thesis is to evaluate five earlier evaluation reports on consolidation centres. Based on these evaluation reports and other relevant literature, it is recommended how a coordinated freight logistic project should be organized in Norra Djurgårdsstaden and how the impact on the environment and energy consumption should be calculated. The evaluation reports are from the logistic centre in the Old Town of Stockholm, the pilot project Samlic in Linköping, the urban consolidation centre in Norwich, the micro-consolidation centre in London and several urban logistic practices in Utrecht. A thorough comparative analysis of the five different evaluation reports has looked at the initiators and the stakeholders, the delivery situation before and after the implementation of the consolidation centre as well as done a deeper evaluation analysis of all the evaluation reports. The comparative analysis showed that the consolidation centres have had a positive effect on decreasing the number of delivery vehicles in the city district and thereby reducing the emissions and the energy consumption from the delivery vehicles. Based on the comparative analysis and other literature it is suggested that the initiative to build a consolidation centre in Norra Djurgårdsstaden has to come from the City of Stockholm. The stakeholders should be the City of Stockholm, logistics companies, freight companies, the different businesses in the area and the Ports of Stockholm. To encourage even more businesses to have deliveries from the consolidation centre and get more environmentally friendly delivery vehicles in the city district it might be necessary to use several management control instruments. Examples of control instruments are environmental zones, time windows and implement different restrictions on the delivery vehicles. It is essential to gather information about the delivery vehicles in the city district to estimate emissions and the energy consumption. The collection of data from the delivery vehicles can be gathered from consignment notes, driver notes, invoice data or statistics of the number of vehicles that have delivered goods in the city centre from freight and logistics companies. Then the delivery vehicles impact on energy consumption and the environment can be estimated with the computer tool Network of transports and environment (NTM-method).Norra Djurgårdsstaden är det största pågående byggprojektet i Sverige och är planerat att slutföras under 2030. Stadsdelen ligger i nordöstra Stockholm, i ett före detta industriområde där cirka 12 000 nya bostäder och 35 000 arbetsplatser är planerade att byggas. Stadsdelen har ett starkt fokus på att minska miljöeffekterna och påverkan av energianvändningen. En av idéerna för att uppfylla detta är att införa samordnad varulogistik. Detta kan göras genom att bygga ett logistikcenter där gods från olika logistikföretag och godstransportörer kan lastas på samma leveransfordon och sedan levereras inom samma område i Norra Djurgårdsstaden. Syftet med detta examensarbete är att utvärdera fem tidigare utvärderingsrapporter om logistikcenter. Med hjälp av dessa utvärderingsrapporter och annan litteratur ges det förslag på hur ett projekt inom samordnad varulogistik kan organiseras i Norra Djurgårdsstaden och hur miljöpåverkan och energiförbrukning från leveransfordonen kan beräknas. Utvärderingsrapporterna kommer från logistikcentret i Gamla Stan i Stockholm, pilotprojektet Samlic i Linköping, logistikcentret i Norwich, mikro-logistikcentret i London och olika logistikmetoder i Utrecht. En noggrann jämförande analys av de fem olika utvärderingsrapporterna har undersökt initiativtagare och intressenter, leveranssituationerna före och efter uppförandet av logistikcentren samt gjort en fördjupad utvärderingsanalys av samtliga utvärderingsrapporter. Den jämförande analysen visar att införandet av logistikcenter har haft en positiv effekt för att minska antalet leveransfordon i stadsdelen och därmed inneburit minskade utsläpp och lägre energianvändning för leveransfordonen. Baserad på den komparativa analysen och annan litteratur föreslås det att initiativet i Norra Djurgårdsstaden måste komma från Stockholms stad. Intressenterna bör vara Stockholms Stad, logistikföretag, godstransportörer, de olika företagen i området och Stockholms Hamnar. För att få fler företag att använda logistikcentret samt att få miljövänligare leveransfordon i stadsdelen kan det vara nödvändigt att använda flera styrmedel. Exempel på styrmedel är miljözoner, tidsfönster och att införa olika begränsningar på leveransfordon. Det är väsentligt att samla information om leveransfordonen i stadsdelen för att beräkna utsläpp och energianvändning. Insamlingen av data från leveransfordon kan hämtas från fraktsedlar, fakturaunderlag eller statistik över antalet fordon som har levererat varor i stadsdelen från frakt-och logistikföretag. Då kan miljö- och energieffekterna från leveransfordonen beräknas med dataverktyget Nätverket för transporter och miljö (NTM-metoden).
31
Lee, Joo-Kiong. "Radiowave propagation over an irregular terrain using the parabolic equation method in a curvilinear coordinate system." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1995. http://handle.dtic.mil/100.2/ADA297694.
Повний текст джерела
32
Breheny, Patrick John. "Regularized methods for high-dimensional and bi-level variable selection." Diss., University of Iowa, 2009. https://ir.uiowa.edu/etd/325.
Повний текст джерелаАнотація:
Many traditional approaches cease to be useful when the number of variables is large in comparison with the sample size. Penalized regression methods have proved to be an attractive approach, both theoretically and empirically, for dealing with these problems. This thesis focuses on the development of penalized regression methods for high-dimensional variable selection. The first part of this thesis deals with problems in which the covariates possess a grouping structure that can be incorporated into the analysis to select important groups as well as important members of those groups. I introduce a framework for grouped penalization that encompasses the previously proposed group lasso and group bridge methods, sheds light on the behavior of grouped penalties, and motivates the proposal of a new method, group MCP.
The second part of this thesis develops fast algorithms for fitting models with complicated penalty functions such as grouped penalization methods. These algorithms combine the idea of local approximation of penalty functions with recent research into coordinate descent algorithms to produce highly efficient numerical methods for fitting models with complicated penalties. Importantly, I show these algorithms to be both stable and linear in the dimension of the feature space, allowing them to be efficiently scaled up to very large problems.
In the third part of this thesis, I extend the idea of false discovery rates to penalized regression. The Karush-Kuhn-Tucker conditions describing penalized regression estimates provide testable hypotheses involving partial residuals. I use these hypotheses to connect the previously disparate elds of multiple comparisons and penalized regression, develop estimators for the false discovery rates of methods such as the lasso and elastic net, and establish theoretical results.
Finally, the methods from all three sections are studied in a number of simulations and applied to real data from gene expression and genetic association studies.
33
Sutisna, S. "The three-dimensional combination of absolute and relative coordinates derived from satellite and terrestrial methods." Thesis, University of Newcastle Upon Tyne, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233314.
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34
Gibbons, Sean L. "Impacts of sigma coordinates on the Euler and Navier-Stokes equations using continuous Galerkin methods." Thesis, Monterey, Calif. : Naval Postgraduate School, 2009. http://edocs.nps.edu/npspubs/scholarly/theses/2009/March/09Mar%5FGibbons.pdf.
Повний текст джерелаАнотація:
Thesis (M.S. in Meteorology and M.S. in Applied Mathematics )--Naval Postgraduate School, March 2009.Thesis Advisor(s): Giraldo, Francis X. ; Eckel, Tony. "March 2009." Description based on title screen as viewed on 23 April 2009. Author(s) subject terms: Sigma coordinates, Continuous Galerkin, Euler Equations, Navier-Stokes Equations, linear hydrostatic mountain, linear non-hydrostatic mountain, explicit time integration, RK35, Runge-Kutta. Includes bibliographical references (p. 71-74). Also available in print.
35
Hinohara, Nobuo. "Microscopic description of nuclear large-amplitude collective motion by means of the adiabatic self-consistent collective coordinate method." 京都大学 (Kyoto University), 2008. http://hdl.handle.net/2433/136880.
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36
Kobayasi, Masato. "A microscopic study of the shape coexistence phenomena by means of the adiabatic self-consistent collective coordinate method." 京都大学 (Kyoto University), 2005. http://hdl.handle.net/2433/145078.
Повний текст джерелаАнотація:
Kyoto University (京都大学)0048
新制・課程博士
博士(理学)
甲第11310号
理博第2868号
新制||理||1429(附属図書館)
22953
UT51-2005-D61
京都大学大学院理学研究科物理学･宇宙物理学専攻
(主査)助教授 松柳 研一, 教授 堀内 昶, 教授 中村 卓史
学位規則第4条第1項該当
37
Kim, Heeyoung. "Statistical methods for function estimation and classification." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/44806.
Повний текст джерелаАнотація:
This thesis consists of three chapters. The first chapter focuses on adaptive smoothing splines for fitting functions with varying roughness. In the first part of the first chapter, we study an asymptotically optimal procedure to choose the value of a discretized version of the variable smoothing parameter in adaptive smoothing splines. With the choice given by the multivariate version of the generalized cross validation, the resulting adaptive smoothing spline estimator is shown to be consistent and asymptotically optimal under some general conditions. In the second part, we derive the asymptotically optimal local penalty function, which is subsequently used for the derivation of the locally optimal smoothing spline estimator. In the second chapter, we propose a Lipschitz regularity based statistical model, and apply it to coordinate measuring machine (CMM) data to estimate the form error of a manufactured product and to determine the optimal sampling positions of CMM measurements. Our proposed wavelet-based model takes advantage of the fact that the Lipschitz regularity holds for the CMM data. The third chapter focuses on the classification of functional data which are known to be well separable within a particular interval. We propose an interval based classifier. We first estimate a baseline of each class via convex optimization, and then identify an optimal interval that maximizes the difference among the baselines. Our interval based classifier is constructed based on the identified optimal interval. The derived classifier can be implemented via a low-order-of-complexity algorithm.
38
Beltran, Royo César. "Generalized unit commitment by the radar multiplier method." Doctoral thesis, Universitat Politècnica de Catalunya, 2001. http://hdl.handle.net/10803/6501.
Повний текст джерелаАнотація:
This operations research thesis should be situated in the field of the power generation industry. The general objective of this work is to efficiently solve the Generalized Unit Commitment (GUC) problem by means of specialized software. The GUC problem generalizes the Unit Commitment (UC) problem by simultane-ously solving the associated Optimal Power Flow (OPF) problem. There are many approaches to solve the UC and OPF problems separately, but approaches to solve them jointly, i.e. to solve the GUC problem, are quite scarce. One of these GUC solving approaches is due to professors Batut and Renaud, whose methodology has been taken as a starting point for the methodology presented herein.This thesis report is structured as follows. Chapter 1 describes the state of the art of the UC and GUC problems. The formulation of the classical short-term power planning problems related to the GUC problem, namely the economic dispatching problem, the OPF problem, and the UC problem, are reviewed. Special attention is paid to the UC literature and to the traditional methods for solving the UC problem. In chapter 2 we extend the OPF model developed by professors Heredia and Nabona to obtain our GUC model. The variables used and the modelling of the thermal, hydraulic and transmission systems are introduced, as is the objective function. Chapter 3 deals with the Variable Duplication (VD) method, which is used to decompose the GUC problem as an alternative to the Classical Lagrangian Relaxation (CLR) method. Furthermore, in chapter 3 dual bounds provided by the VDmethod or by the CLR methods are theoretically compared.
Throughout chapters 4, 5, and 6 our solution methodology, the Radar Multiplier (RM) method, is designed and tested. Three independent matters are studied: first, the auxiliary problem principle method, used by Batut and Renaud to treat the inseparable augmented Lagrangian, is compared with the block coordinate descent method from both theoretical and practical points of view. Second, the Radar Sub- gradient (RS) method, a new Lagrange multiplier updating method, is proposed and computationally compared with the classical subgradient method. And third, we study the local character of the optimizers computed by the Augmented Lagrangian Relaxation (ALR) method when solving the GUC problem. A heuristic to improve the local ALR optimizers is designed and tested.
Chapter 7 is devoted to our computational implementation of the RM method, the MACH code. First, the design of MACH is reviewed brie y and then its performance is tested by solving real-life large-scale UC and GUC instances. Solutions computed using our VD formulation of the GUC problem are partially primal feasible since they do not necessarily fulfill the spinning reserve constraints. In chapter 8 we study how to modify this GUC formulation with the aim of obtaining full primal feasible solutions. A successful test based on a simple UC problem is reported. The conclusions, contributions of the thesis, and proposed further research can be found in chapter 9.
39
Yamakawa, Yuya. "Studies on Optimization Methods for Nonlinear Semidefinite Programming Problems." 京都大学 (Kyoto University), 2015. http://hdl.handle.net/2433/199446.
Повний текст джерела
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Suhara, Tadahiro. "The coexistence of cluster and shell-model structures in light nuclei studied with antisymmetrized molecular dynamics and generator coordinate method." 京都大学 (Kyoto University), 2011. http://hdl.handle.net/2433/142370.
Повний текст джерела
41
Santhanam, Siva priya. "Child-Related Factors That Influence Responsiveness In Mothers Of Preschool-Age Children With Autism Spectrum Disorders: A Mixed-Methods Study." Bowling Green State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1395145355.
Повний текст джерела
42
Keating, Chris M. "A Method for Achieving Analytic Formulas for Three Body Integrals Consisting of Powers and Exponentials in All Three Interparticle Hylleraas Coordinates." Thesis, Portland State University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=1606197.
Повний текст джерелаАнотація:
After an introduction to the variational principle of three body systems via the Helium atom, we present general analytical formulas for the radial parts of integrals that occur when three body systems are described using wave functions that consist of powers and exponentials in all three interparticle Hylleraas coordinates [Hylleraas1929]. This work is an extension of integrals given by Harris, Frolov and Smith, Jr. [Harris2004]. Specifically included are radial integrals encountered in calculations involving the dipole moment matrix element in Hylleraas coordinates that contain a function f(kr 1) (such as a spherical Bessel function) in addition to a plane wave, a hydrogenic orbital and exponentials in all three interparticle coordinates.
43
Keating, Chris M. "A Method for Achieving Analytic Formulas for Three Body Integrals Consisting of Powers and Exponentials in All Three Interparticle Hyllerass Coordinates." PDXScholar, 2015. https://pdxscholar.library.pdx.edu/open_access_etds/2638.
Повний текст джерелаАнотація:
After an introduction to the variational principle of three body systems via the Helium atom, we present general analytical formulas for the radial parts of integrals that occur when three body systems are described using wave functions that consist of powers and exponentials in all three interparticle Hylleraas coordinates [Hylleraas1929]. This work is an extension of integrals given by Harris, Frolov and Smith, Jr. [Harris2004]. Specifically included are radial integrals encountered in calculations involving the dipole moment matrix element in Hylleraas coordinates that contain a function f(kr1) (such as a spherical Bessel function) in addition to a plane wave, a hydrogenic orbital and exponentials in all three interparticle coordinates.
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Yildiz, Ozgur. "Implementation Of Mesh Generation Algorithms." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/1339621/index.pdf.
Повний текст джерелаАнотація:
In this thesis, three mesh generation software packages have been developed and
implemented. The first two were based on structured mesh generation algorithms
and used to solve structured surface and volume mesh generation problems of
three-dimensional domains. Structured mesh generation algorithms were based
on the concept of isoparametric coordinates. In structured surface mesh
generation software, quadrilateral mesh elements were generated for complex
three-dimensional surfaces and these elements were then triangulated in order to
obtain high-quality triangular mesh elements. Structured volume mesh
generation software was used to generate hexahedral mesh elements for volumes.
Tetrahedral mesh elements were constructed from hexahedral elements using
hexahedral node insertion method. The results, which were produced by the mesh
generation algorithms, were converted to a required format in order to be saved in output files. The third software package is an unstructured quality tetrahedral
mesh generator and was used to generate exact Delaunay tetrahedralizations,
constrained (conforming) Delaunay tetrahedralizations and quality conforming
Delaunay tetrahedralizations. Apart from the mesh generation algorithms used
and implemented in this thesis, unstructured mesh generation techniques that can
be used to generate quadrilateral, triangular, hexahedral and tetrahedral mesh
elements were also discussed.
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高下, 和浩, Kazuhiro KOHGE, 吉泰 峯村, Kiyoshi MINEMURA, 知実 内山 та Tomomi UCHIYAMA. "三次元一般曲線座標系に対するCIP法粘性流解法". 日本機械学会, 2000. http://hdl.handle.net/2237/9217.
Повний текст джерела
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Lewis, Thomas Frederick. "Special Educational Need Coordinator (SENCO) wellbeing : a mixed methods exploration of workplace demands and effective coping actions." Thesis, University of Birmingham, 2017. http://etheses.bham.ac.uk//id/eprint/7781/.
Повний текст джерелаАнотація:
Occupational stress (OS) presents a significant threat to teachers’ wellbeing. High levels of OS can impact multiple areas, including teachers’ health, job-performance, schools’ financial resources, and pupils’ wellbeing. Special Educational Needs Coordinators (SENCOs) play a critical role in coordinating provision for pupils with special educational needs, and represent a group that have received little research attention in relation to OS and wellbeing. This research adopted a sequential exploratory mixed-methods design to explore the extent, causes, and means of effectively managing OS in the SENCO role. The role that educational psychologists (EPs) can play in supporting SENCOs to manage OS was also explored. 38 practicing SENCOs from a local authority in the West Midlands, England, participated in the study. Participant views were gathered using questionnaires and semi-structured interviews, and were analysed via descriptive statistics and thematic analysis. 84% of participants reported to find the role ‘moderately stressful’, ‘very stressful’ or ‘extremely stressful’. Factors which were perceived to cause OS a.) most frequently, and b.) to the greatest extent were identified. These were diverse and included those related to workload and resource availability, as well as those related to the status of the role, and relational and emotional factors. Approaches that enabled participants to cope well with OS, despite facing high workplace demands were also identified, as were means through which educational psychologists could support SENCOs in managing OS. Participants’ beliefs about the role, relationships, cognitive resources, and the culture and systems within their school were instrumental in coping with OS. It was perceived that EPs could support SENCOs in managing OS through contact, working in a child and school-centred manner, and through facilitating problem-solving. Findings are discussed in relation to extant literature, and implications for theory and educational psychology practice are also highlighted.
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Wu, Wei. "Paving the Randomized Gauss-Seidel." Scholarship @ Claremont, 2017. http://scholarship.claremont.edu/scripps_theses/1074.
Повний текст джерелаАнотація:
The Randomized Gauss-Seidel Method (RGS) is an iterative algorithm that solves overdetermined systems of linear equations Ax = b. This paper studies an update on the RGS method, the Randomized Block Gauss-Seidel Method. At each step, the algorithm greedily minimizes the objective function L(x) = kAx bk2 with respect to a subset of coordinates. This paper describes a Randomized Block Gauss-Seidel Method (RBGS) which uses a randomized control method to choose a subset at each step. This algorithm is the first block RGS method with an expected linear convergence rate which can be described by the properties of the matrix A and its column submatrices. The analysis demonstrates that RBGS improves RGS more when given appropriate column-paving of the matrix, a partition of the columns into well-conditioned blocks. The main result yields a RBGS method that is more e cient than the simple RGS method.
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Chahad, Alexandre Pereira. "Estudo de um formalismo para discretizar eficientemente as equações integrais do Método da Coordenada Geradora Hartree-Fock." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/75/75131/tde-07102009-092235/.
Повний текст джерелаАнотація:
A busca por um conjunto de bases de alta qualidade é feita por vários grupos, pois a utilização destes conjuntos é importante para a obtenção de resultados exatos, tanto para propriedades atômicas quanto para propriedades moleculares. Os conjuntos usados neste trabalho são constituídos através da utilização do Método da Coordenada Geradora Hartree-Fock em sua versão polinomial e foram construídos de forma a permitirem uma maior flexibilidade à camada de valência do átomo, flexibilidade esta que foi proporcionada pelo número de funções que descrevem a última camada do átomo. Uma nova metodologia para a construção de conjuntos de base foi proposta neste trabalho. Esta nova metodologia diminui a busca artesanal pela busca pelos conjuntos de base introduzindo o Método Simplex em nosso programa gerador de base GENBASIS minimizando o tempo de procura por essa bases de qualidade. A aplicação destes conjuntos para estimativa de propriedades atômicas e moleculares foi feita em comparação com conjuntos de base largamente utilizados na literatura, envolvendo cálculos com vários níveis de teoria, desde o método Hartree-Fock até a Teoria do Funcional Densidade.The search for high quality basis set is made by several groups since the quality of the basis sets is a very important factor to obtain accurate results for atomic and molecular properties. The basis sets used in this work are designed by using the polynomial Generate Coordinate Method and were constructed with the aim to improve the flexibility of a basis sets to describe the valence shell. A new methodology for the search of this basis set is proposed in this work. This new methodology makes the search for this basis set less artisanal with the introduction of the Simplex Method in our basis generator program, GENBASIS. This introduction minimizes the time used in the search for these quality basis set. The application of our basis sets in atomic and molecular calculations were compared with the most used basis sets in the literature and were performed by using different level of calculations, namely, from Hartree-Fock to Density Functional Theory.
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Montenegro, Chingal Jessica Maribel [Verfasser], Christoph [Akademischer Betreuer] Buchheim, and Angelika [Gutachter] Wiegele. "A coordinate ascent method for solving semidefinite relaxations of non-convex quadratic integer programs / Jessica Maribel Montenegro Chingal ; Gutachter: Angelika Wiegele ; Betreuer: Christoph Buchheim." Dortmund : Universitätsbibliothek Dortmund, 2017. http://d-nb.info/1132813778/34.
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Savas, Berkant. "Algorithms in data mining using matrix and tensor methods." Doctoral thesis, Linköpings universitet, Beräkningsvetenskap, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-11597.
Повний текст джерелаАнотація:
In many fields of science, engineering, and economics large amounts of data are stored and there is a need to analyze these data in order to extract information for various purposes. Data mining is a general concept involving different tools for performing this kind of analysis. The development of mathematical models and efficient algorithms is of key importance. In this thesis we discuss algorithms for the reduced rank regression problem and algorithms for the computation of the best multilinear rank approximation of tensors. The first two papers deal with the reduced rank regression problem, which is encountered in the field of state-space subspace system identification. More specifically the problem is \[ \min_{\rank(X) = k} \det (B - X A)(B - X A)\tp, \] where $A$ and $B$ are given matrices and we want to find $X$ under a certain rank condition that minimizes the determinant. This problem is not properly stated since it involves implicit assumptions on $A$ and $B$ so that $(B - X A)(B - X A)\tp$ is never singular. This deficiency of the determinant criterion is fixed by generalizing the minimization criterion to rank reduction and volume minimization of the objective matrix. The volume of a matrix is defined as the product of its nonzero singular values. We give an algorithm that solves the generalized problem and identify properties of the input and output signals causing a singular objective matrix. Classification problems occur in many applications. The task is to determine the label or class of an unknown object. The third paper concerns with classification of handwritten digits in the context of tensors or multidimensional data arrays. Tensor and multilinear algebra is an area that attracts more and more attention because of the multidimensional structure of the collected data in various applications. Two classification algorithms are given based on the higher order singular value decomposition (HOSVD). The main algorithm makes a data reduction using HOSVD of 98--99 \% prior the construction of the class models. The models are computed as a set of orthonormal bases spanning the dominant subspaces for the different classes. An unknown digit is expressed as a linear combination of the basis vectors. The resulting algorithm achieves 5\% in classification error with fairly low amount of computations. The remaining two papers discuss computational methods for the best multilinear rank approximation problem \[ \min_{\cB} \| \cA - \cB\| \] where $\cA$ is a given tensor and we seek the best low multilinear rank approximation tensor $\cB$. This is a generalization of the best low rank matrix approximation problem. It is well known that for matrices the solution is given by truncating the singular values in the singular value decomposition (SVD) of the matrix. But for tensors in general the truncated HOSVD does not give an optimal approximation. For example, a third order tensor $\cB \in \RR^{I \x J \x K}$ with rank$(\cB) = (r_1,r_2,r_3)$ can be written as the product \[ \cB = \tml{X,Y,Z}{\cC}, \qquad b_{ijk}=\sum_{\lambda,\mu,\nu} x_{i\lambda} y_{j\mu} z_{k\nu} c_{\lambda\mu\nu}, \] where $\cC \in \RR^{r_1 \x r_2 \x r_3}$ and $X \in \RR^{I \times r_1}$, $Y \in \RR^{J \times r_2}$, and $Z \in \RR^{K \times r_3}$ are matrices of full column rank. Since it is no restriction to assume that $X$, $Y$, and $Z$ have orthonormal columns and due to these constraints, the approximation problem can be considered as a nonlinear optimization problem defined on a product of Grassmann manifolds. We introduce novel techniques for multilinear algebraic manipulations enabling means for theoretical analysis and algorithmic implementation. These techniques are used to solve the approximation problem using Newton and Quasi-Newton methods specifically adapted to operate on products of Grassmann manifolds. The presented algorithms are suited for small, large and sparse problems and, when applied on difficult problems, they clearly outperform alternating least squares methods, which are standard in the field.