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Everett, Pauline. "A relational defence of surrogate motherhood." Thesis, Durham University, 2011. http://etheses.dur.ac.uk/4464/.
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This thesis explores surrogate motherhood using Christian ethics within a relational framework. A surrogate mother is a woman who has a child for a commissioning couple who are usually infertile. Chapter one explores how surrogacy is presented in three secular and three Church reports by focusing upon the surrogate, the commissioning couple and the child. The key theological and ethical objections to surrogacy are briefly explored: that it undermines motherhood, involves baby selling, coercion, exploitation and commodification. Chapter two analyses motherhood according to three secular feminists and three theologians. The secular feminists are criticised for not recognising the complexity of motherhood. By contrast, motherhood in Christianity is presented as multidimensional. Chapter three analyses whether paid surrogacy commodifies, exploits and coerces the participants. Theologically the chapter explores human beings as created in the image of God and as having dignity, which can mean that payment does not always have to lead to commodification, exploitation or coercion. Chapter four explores whether paid surrogacy involves baby selling. Theologically the chapter explores the concepts of the self and other in Augustine and Aquinas. It also explores agape in Anders Nygren and Gene Outka, arguing that self-interest and altruism can co-exist with care for the self and the other in a relational framework without detriment. Comparisons are made with blood donation to suggest that paid and unpaid surrogacy can operate together without paid surrogacy being regarded as baby selling or the purchase of parenthood. Finally, chapter five outlines three models towards surrogacy: a contract model, an adoption model and my relational approach, influenced by Louis Janssens’ personalism. My relationalism aims for a more sophisticated ontology of the relationship between the self and the other and calls for various solutions in a surrogacy custody dispute.
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G'Fellers, Jeanne. "Surrogate." Digital Commons @ East Tennessee State University, 2017. https://www.amzn.com/1944591338/.
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Worker. Trade Agent. Serf. Etain Ixtii detests the labels others give her, but there are some things she must accept. She was genetically designed to do specific tasks. Her breeding instincts interrupt her life every forty-five days. But workers like Etain are taught not to question so when she returns from training questioning her home world Gno's profit-based caste system, she risks her life. She doesn't want to be an agent and doesn't want to cross through the wormhole to never return. Why does she have to go? Can't someone else?
Usurer Serria, the owner of Etain's birth and training debt, quickly tires of her problem worker and launches Etain through a collapsing wormhole so she can collect the insurance payout. Very bad business indeed, but Etain manages to survive the attempt, arriving on the other side plagued by debilitating headaches and hounded by a dangerous insectoid enemy that no one, including Physician Leigheas Sternbow, the Takla royal physician, and Mercine Feney, the Empire's powerful female leader, can make disappear.https://dc.etsu.edu/alumni_books/1028/thumbnail.jpg
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Leek, Jeffrey Tullis. "Surrogate variable analysis /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/9586.
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Dyers, Bianca. "Does the involvement of third parties in surrogacy agreements raise the risk of exploitation of prospective surrogates and prospective parent(s)?" University of Western Cape, 2019. http://hdl.handle.net/11394/7578.
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Magister Legum - LLMSurrogacy on many occasions is referred to a million-dollar industry. Just like many countries, South Africa has prohibited commercial surrogacy, thus South Africa only permits altruistic surrogacy. The prohibition has consequences for third parties such as surrogacy agencies and surrogacy facilitators, as their right to occupation freedom which is guaranteed by the Constitution of the Republic of South Africa, is limited. No right is absolute, any right can be limited if it can be proved that it is in the best interest of the public. The prohibition on commercial surrogacy is argued to be in the best interest of the public as it can lead to the exploitation of women and the commodification of children.
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Loshchilov, Ilya. "Surrogate-Assisted Evolutionary Algorithms." Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-00823882.
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Les Algorithmes Évolutionnaires (AEs) ont été très étudiés en raison de leur capacité à résoudre des problèmes d'optimisation complexes en utilisant des opérateurs de variation adaptés à des problèmes spécifiques. Une recherche dirigée par une population de solutions offre une bonne robustesse par rapport à un bruit modéré et la multi-modalité de la fonction optimisée, contrairement à d'autres méthodes d'optimisation classiques telles que les méthodes de quasi-Newton. La principale limitation de AEs, le grand nombre d'évaluations de la fonction objectif, pénalise toutefois l'usage des AEs pour l'optimisation de fonctions chères en temps calcul. La présente thèse se concentre sur un algorithme évolutionnaire, Covariance Matrix Adaptation Evolution Strategy (CMA-ES), connu comme un algorithme puissant pour l'optimisation continue boîte noire. Nous présentons l'état de l'art des algorithmes, dérivés de CMA-ES, pour résoudre les problèmes d'optimisation mono- et multi-objectifs dans le scénario boîte noire. Une première contribution, visant l'optimisation de fonctions coûteuses, concerne l'approximation scalaire de la fonction objectif. Le meta-modèle appris respecte l'ordre des solutions (induit par la valeur de la fonction objectif pour ces solutions) ; il est ainsi invariant par transformation monotone de la fonction objectif. L'algorithme ainsi défini, saACM-ES, intègre étroitement l'optimisation réalisée par CMA-ES et l'apprentissage statistique de meta-modèles adaptatifs ; en particulier les meta-modèles reposent sur la matrice de covariance adaptée par CMA-ES. saACM-ES préserve ainsi les deux propriété clé d'invariance de CMA-ES~: invariance i) par rapport aux transformations monotones de la fonction objectif; et ii) par rapport aux transformations orthogonales de l'espace de recherche. L'approche est étendue au cadre de l'optimisation multi-objectifs, en proposant deux types de meta-modèles (scalaires). La première repose sur la caractérisation du front de Pareto courant (utilisant une variante mixte de One Class Support Vector Machone (SVM) pour les points dominés et de Regression SVM pour les points non-dominés). La seconde repose sur l'apprentissage d'ordre des solutions (rang de Pareto) des solutions. Ces deux approches sont intégrées à CMA-ES pour l'optimisation multi-objectif (MO-CMA-ES) et nous discutons quelques aspects de l'exploitation de meta-modèles dans le contexte de l'optimisation multi-objectif. Une seconde contribution concerne la conception d'algorithmes nouveaux pour l'optimi\-sation mono-objectif, multi-objectifs et multi-modale, développés pour comprendre, explorer et élargir les frontières du domaine des algorithmes évolutionnaires et CMA-ES en particulier. Spécifiquement, l'adaptation du système de coordonnées proposée par CMA-ES est couplée à une méthode adaptative de descente coordonnée par coordonnée. Une stratégie adaptative de redémarrage de CMA-ES est proposée pour l'optimisation multi-modale. Enfin, des stratégies de sélection adaptées aux cas de l'optimisation multi-objectifs et remédiant aux difficultés rencontrées par MO-CMA-ES sont proposées.
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Smith, Clara A. "The black surrogate mother." DigitalCommons@Robert W. Woodruff Library, Atlanta University Center, 2011. http://digitalcommons.auctr.edu/dissertations/298.
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This study examines the literary depiction of the black surrogate mother as she is created according to the author’s race, gender, background, experience, biases and goals. Even though she is one of the most successful and popular characters of fiction, she is also controversial. Her reputation is iconic as well as dichotomous. For example, she is credited for the exemplary upbringing of her white charges, while simultaneously blamed for neglecting her own children. Particularly, this paper looks at three black surrogate mothers who conform to the prototypical, often stereotypical, image of the black surrogate mother: Mammy, Aunt Mammy Jane, and Dilsey. The critique substantiates that Mitchell and Faulkner, respectively, were invested in depicting Mammy and Dilsey as representatives of the real black surrogate mothers of their lives. Although, the character of Mammy Jane mirrors Mammy and Dilsey in her commitment and devotion to her white family, Chesnutt employs her as a cautionary warning to the blacks who refuse to accept change and progress after Emancipation. The other three black surrogate mothers, Sofia, Berenice, and Ondine, are antithetical to the stereotypical black surrogate mother. Sofia, an accidental maid, is representative of Walker’s intense efforts to deconstruct the image of the black surrogate mother that plagued her throughout her lifetime. Unlike most white authors, McCullers crafts Berenice as independent, strong, and autonomous, not just as a black surrogate mother of a white child. Morrison provides Ondine with a husband and daughter to be concerned with so that she cannot be cast as the stereotypically loving, nurturing black mother of white children. The conclusion of this study validates that the literary black surrogate mother is most often a creation based upon her author’s specific and personal biases and goals. In conjunction with the above assertion, the critique also contends that the real life black domestic has been and will continue to be significantly influenced by her fictional representative.
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Feng, Chunyao Seaman John Weldon. "Bayesian evaluation of surrogate endpoints." Waco, Tex. : Baylor University, 2006. http://hdl.handle.net/2104/4187.
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Lewis, Nigel da Costa. "Surrogate markers in clinical trials." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620204.
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Jaiem, Karim. "High Speed Surrogate Vehicle Development." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-69078.
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In order to keep down the costs in the automotive industry, it is decided to simulate dangerous scenarios that could occur in traffic, either virtually or by means of custom-made vehicles. This report addresses the development of a new type of surrogate vehicle called High Speed Surrogate Vehicle. This project has been carried out to prevent today's issues with surrogate vehicles and to enable an increase in testing efficiency, without increasing the risk of damaging test vehicles and injuries on personnel in an eventual collision.The report presents the surrogate vehicles area of use and its technical components. Reflection measurements have been made to compare radar characteristic between a real car and surrogate target and construction work has been carried out to manufacture fasteners for attaching the new High Speed Surrogate Vehicle. In the last phase of this degree project, final performance tests and collision tests were performed to verify its drive-and collision ability against test cars.
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Azzi, Soumaya. "Surrogate modeling of stochastic simulators." Electronic Thesis or Diss., Institut polytechnique de Paris, 2020. http://www.theses.fr/2020IPPAT009.
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Cette thèse propose des outils statistiques pour étudier l’impact qu’a la morphologie d’une ville sur l’exposition des populations induite par un champ électromagnétique provenant d’une station de base. Pour cela l’exposition a été évaluée numériquement en propageant (via des techniques de lancer de rayons) les champs émis dans une antenne dans des villes aléatoires. Ces villes aléatoires ont les mêmes caractéristiques macroscopiques (e.g. hauteur moyenne des immeubles, largeur moyenne des rues et anisotropie) mais sont distinctes les unes des autres. Pour les mêmes caractéristiques de nombreuses villes aléatoires ont été générées et l’exposition induite a été calculée pour chacune. Par conséquent, chaque combinaison de variables correspond à plusieurs valeurs d’exposition. L’exposition est décrite par une distribution statistique non nécessairement gaussienne. Ce comportement stochastique est présent en plusieurs problèmes industriels et souvent les nombreuses simulations menées ont un cout de calcul important. Les travaux de cette thèse étudient la modélisation de substitution des fonctions aléatoires. Le simulateur stochastique est considéré comme un processus stochastique. On propose une approche non paramétrique basée sur la décomposition de Karhunen-Loève du processus stochastique. La fonction de substitution a l’avantage d’être très peu coûteuse à exécuter et à fournir des prédictions précises.En effet, l’objectif de la thèse consiste à évaluer la sensibilité de l’exposition aux caractéristiques morphologiques d’une ville. On propose une approche d’analyse de sensibilité tenant compte de l’aspect stochastique du modèle. L’entropie différentielle du processus stochastique est évaluée et la sensibilité est estimée en calculant les indices de Sobol de l’entropie. La variance de l’entropie est exprimée en fonction de la variabilité de chacune des variables d’entréeThis thesis is a contribution to the surrogate modeling and the sensitivity analysis on stochastic simulators. Stochastic simulators are a particular type of computational models, they inherently contain some sources of randomness and are generally computationally prohibitive. To overcome this limitation, this manuscript proposes a method to build a surrogate model for stochastic simulators based on Karhunen-Loève expansion. This thesis also aims to perform sensitivity analysis on such computational models. This analysis consists on quantifying the influence of the input variables onto the output of the model. In this thesis, the stochastic simulator is represented by a stochastic process, and the sensitivity analysis is then performed on the differential entropy of this process.The proposed methods are applied to a stochastic simulator assessing the population’s exposure to radio frequency waves in a city. Randomness is an intrinsic characteristic of the stochastic city generator. Meaning that, for a set of city parameters (e.g. street width, building height and anisotropy) does not define a unique city. The context of the electromagnetic dosimetry case study is presented, and a surrogate model is built. The sensitivity analysis is then performed using the proposed method
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Rispel, Shane-Leane. "The scope and content of the child's right to identidy in the context of surrogacy." Thesis, University of the Western Cape, 2017. http://hdl.handle.net/11394/5703.
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Magister Legum - LLMThe development of assisted reproductive technology (ART) has radically changed the landscape of the conventional family. It has permitted a platform for the creation of families and family structures with tremendous diversity in their demographic characteristics. It has also changed the way in which individuals become parents. The advances in medical and scientific fertility treatments have meant that for many the dream of having a child of their own has now become a real possibility. Public perception and attitudes towards infertility treatments and more latterly surrogacy has changed tremendously and becoming increasingly acceptable. While there are those who have celebrated the advancement in reproductive technologies and potential freedoms that this may contain, ART has opened the proverbial Pandora's Box amongst scholars and the public policy makers, principally in the area of rights.
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Trowse, Philippa Mary. "Exploitation and harm in the context of Indian commercial surrogate women." Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/120021/2/Philippa_Trowse_Thesis.pdf.
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The law relating to commercial surrogacy is complex and presents many problems for legislators, intended parents and those acting as surrogate women, both within and outside Australia. This research conducted a comprehensive legal analysis, a social science analysis of empirical research using the experience of Indian women as a case study, and a theoretical critique of policy values underpinning the prohibition of commercial surrogacy in Australia using Mill's harm principle and the theory of exploitation as evaluative measures. Findings can inform reforms of legislation, policy and practice in Australia and overseas.
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McClelland, Carol Margaret. "Surrogate markers to determine drug activity." Thesis, University of Kent, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.413298.
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Smith, Christopher P. "Surrogate models for aerodynamic performance prediction." Thesis, University of Surrey, 2015. http://epubs.surrey.ac.uk/808464/.
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Automatic optimisers can play a vital role in the design and development of engineering systems and processes. However, a lack of available data to guide the search can result in the global optimum solution never being found. Surrogate models can be used to address this lack of data and allow more of the design space to be explored, as well as provide an overall computational saving. In this thesis I have developed two novel long-term prediction methods that investigate the use of ensembles of surrogates to perform predictions of aerodynamic data. The models are built using intermediate computational fluid dynamic convergence data. The first method relies on a gradient based learning algorithm to optimise the base learners and the second utilises a hybrid multi-objective evolutionary algorithm. Different selection schemes are investigated to improve the prediction performance and the accuracy of the ensembles are compared to the converged data, as well as to the delta change between flow conditions. Three challenging real world aerodynamic data sets have been used to test the developed algorithms and insights into aerodynamic performance has been gained through analysis of the computational fluid dynamic convergence histories. The trends of the design space can be maintained, as well as achieving suitable overall prediction accuracy. Selecting a subset improves ensemble performance, but no selection method is superior to any others. The hybrid multi-objective evolutionary algorithm approach is also tested on two standard time series prediction tasks and the results presented are competitive with others reported in the literature. In addition, a novel technique that improves a parameter based surrogates learning through the transfer of additional information is also investigated to address the lack of data. Transfer learning has an initial impact on the learning rate of the surrogate, but negative transfer is observed with increasing numbers of epochs. Using the data available for the low dimensional problems, it is shown that the convergence prediction results are comparable to those from the parameter based surrogate. Therefore, the convergence prediction method could be used as a surrogate and form part of an aerodynamic optimisation task. However, there are a number of open questions that need to be addressed, including what is the best use of the surrogate during the search?
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Al-Mohammad, Abdallah. "Hibernating myocardium : prevalence and surrogate markers." Thesis, University of Aberdeen, 2017. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=235453.
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The aims of this thesis are to determine: 1. The true prevalence of hibernating myocardium in patients with severely impaired left ventricular contraction. (Chapter 3) 2. The viability status of the left ventricular wall aneurysm as defined by positron emission tomography. (Chapter 4) 3. The relationship between the incidence of hibernating myocardium and the coronary artery flow grade determined angiographically. (Chapter 5) 4. The relationship between the presence of Q waves (with or without preserved R wave) on the surface electrocardiogram and the presence of scar in the myocardium as diagnosed by positron emission tomography. (Chapter 6) 5. The relationship between the incidence of hibernating myocardium and QT dispersion on the surface electrocardiogram. (Chapter 7) 6. Looking for other markers of hibernation by PET. (Chapters 8 and 9) I proposed to look at the relationship between continuing metabolic activity in 10 akinetic or severely hypokinetic segments as an alternative method and thus as a new definition of pre-operative determination of hibernating myocardium. This is the topic in Chapter 8. Following the completion of question number 3, and the observed role of collateral circulation, I proposed to look into the role of TIMI 0-1 and collaterals grade 2-3 in maintaining viability and their role as a marker of hibernating myocardium. This won support in the form of a research grant from the British Heart Foundation in 1998. This was the topic of my last project, which was added to the thesis after its initial completion on the 23rd of December 2000. This is the topic of Chapter 9. 7. Following the delayed submission of the Thesis in 2015, I was asked to add Chapter 11 which summarised both my contribution since the Thesis was concluded into the topic of Hibernating myocardium; and the knowledge progression into the detection of the phenomenon and its clinical usefulness to bring the Thesis up to date. Methods: The patients were those with coronary artery disease and impaired left ventricular contraction recruited into a series of studies of the presence of hibernating myocardium using positron emission tomography, as the method of choice to preoperatively detect this phenomenon. The patients were either recruited from the cardiac catheterization laboratory or from the cohort of patients presenting with myocardial infarction to the cardiology unit at Aberdeen Royal Infirmary. All the studies were approved by the Grampian Research Ethics Committee. In some of the studies, cardiac magnetic resonance imaging was used for simple assessment of the myocardial contraction and thickening in the study reported in Chapter 9. Results and Conclusions: 1. Hiberanting myocardium affects over 50% of the patients with severe left ventricular systolic impairment with coronary artery disease. (Chapter 3). 2. None of the aneurysmal segments are viable. (Chapter 4) 3. Compared to the areas supplied by arteries with Thrpmbolysis In Myocardial Infarction (TIMI) flow grades 2-3, the areas supplied by almost occluded coronary arteries (TIMI 0-1 flow grades) are significantly more likely to have both evidence of scarred myocardium (highly significantly statistical difference p < 0.0001) and evidence of hibernating myocardium, just reaching statistical significance (p < 0.05). (Chapter 5) 4. The specificity of Q waves on the electrocardiogram (ECG) as markers for 11 myocardial scarring is 79%, with a low sensitivity of 41%. (Chapter 6) 5. Maintaining R waves following a pathological Q wave on the ECG is not helpful for predicting the presence of hibernating myocardium. (Chapter 6) 6. The presence or absence of hibernating myocardium did not impact on native QT dispersion, rate corrected QTc dispersion or on the maximum adjacent QT dispersion on the ECG. (Chapter 7). 7. A new definition of hibernating myocardium is proposed, helping to detect it preoperatively through the demonstration of metabolism – mechanical mismatch defect using a single radio-pharmaceutical. (Chapter 8) 8. As a marker of the classical perfusion –metabolism mismatch defect, the new proposed metabolism-mechanical mismatch defect by PET is sensitive (92%) and specific (97%), with excellent positive and negative predictive accuracies (96% and 93%, respectively). (Chapter 8) 9. While collaterals grade 2-3 supplying territories with blocked arteries and flow grades TIMI 0-1 may be sensitive markers (83%) of hibernating myocardium; they lack specificity (20%), and the differences between the two small groups completing the study did not reach statistical significance. (Chapter 9).
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Niemeyer, Kyle Evan. "Skeletal Mechanism Generation for Surrogate Fuels." Cleveland, Ohio : Case Western Reserve University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=case1259018155.
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Thesis(M.S.)--Case Western Reserve University, 2009Title from PDF (viewed on 2010-01-28) Department of EMC - Aerospace Engineering Includes abstract Includes bibliographical references and appendices Available online via the OhioLINK ETD Center
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Nilsson, Elina. "Surrogatmödraskap: Arbete, gudagåva eller exploatering? : En analys av den svenska debatten kring surrogatmödraskap." Thesis, Uppsala universitet, Centrum för genusvetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-209395.
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Surrogacy is an arrangement in which a woman carries, delivers, and then relinquishes a baby to commissioning parents. The arrangement challenges traditional norms and definitions of reproduction, pregnancy and motherhood, and at the same time raises difficult ethical, philosophical and social questions. There is currently an ongoing debate in Sweden, where all forms of surrogacy is illegal. The debate is polemical and harsh, with advocates arguing that surrogacy is defensible on the basis of individual rights and women's right to choose over their own bodies, and those in opposition are convinced on an intersectional basis that women are being used and exposed on the market of surrogacy.The purpose of this study is to investigate the debate on surrogacy in the Swedish context. Using qualitative text analysis, the study aims to increase understanding about the debate over surrogacy by analyzing texts published in Swedish press during 2010-2013. I have analyzed the advocating arguments as well as the oppositional arguments constructing the ongoing debate of surrogacy with a focus on the transnational relations and the discrepancy between the views on altruistic and commercial forms of surrogacy.The findings indicate that surrogacy is in general seen as either a win-win situation or exploitation and confirms earlier intersectional postcolonial research that centers on surrogacy, which highlights a general tendency to not acknowledge the dimensions and intersections of gender, class, race, and ethnicity. This is crucial especially concerning surrogacy is such a transnational phenomenon, where for example (white) Swedes longing for babies go to India and through an Indian surrogate mother become parents. The study shows that the debate is somewhat a minefield, and while being polemical the debate is also very complex.
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Ostadi, Mohammad. "Surrogate Models for Integrated Reforming Combined Cycle Optimization : Surrogat-modeller til optimalisering av naturgassbaserte kraftverk med integrert reformering." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for energi- og prosessteknikk, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-23052.
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In the light of increasing concerns about climate change, greenhouse gas mitigation technologies have gained growing attention. Integrated Reforming Combined Cycle (IRCC) is one of the processes for reducing CO2 emissions from natural gas (NG) power plants, which could help attenuate the rise in atmospheric temperature.The reforming process, an important part of an IRCC, is a chemical process for fuel conversion and the process model involves chemical equilibrium and reaction kinetics. A first principles model of this process in an optimization framework will be very complex and may involve solving of hundreds (or thousands) of nonlinear equations and therefore is computationally expensive. A so-called surrogate model (or metamodel) is a multivariable general purpose mapping that can be used in an optimization framework to reduce the model complexity and thus reduce computational load in the optimization to something that is manageable. There are many different methods for developing surrogate models varying from "simple" polynomial models to complicated models such a Kriging etc. Objectives for the thesis work were development of Kriging and Polynomial surrogate models for two configurations of IRCC process: air blown and oxygen blown ATR. The figure below gives a brief overview of possible alternatives in the design of an IRCC with CO2 capture. A total of 30 cases were considered for metamodel building with different sample sizes and different number of inputs to metamodels. The built metamodels were compared based on their accuracy in predicting the outputs. Kriging models yield results that are equal or slightly better than Polynomial models in accuracy. One Polynomial and Kriging model were tested in an existing optimization framework to identify a model with best computational cost-accuracy trade-off. The Polynomial model demonstrated faster performance than the Kriging model. Polynomial models with a predictive accuracy close to Kriging models but with an advantage of less computational time will most likely be used for optimization of IRCC plants. The contribution that this thesis has made is better understanding of the process and metamodel building.
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Andersson, Daniel. "Improved accuracy of surrogate models using output postprocessing." Thesis, University of Skövde, School of Humanities and Informatics, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-312.
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Using surrogate approximations (e.g. Kriging interpolation or artifical neural networks) is an established technique for decreasing the execution time of simulation optimization problems. However, constructing surrogate approximations can be impossible when facing complex simulation inputs, and instead one is forced to use a surrogate model, which explicitly attempts to simulate the inner workings of the underlying simulation model. This dissertation has investigated if postprocessing the output of a surrogate model with an artificial neural network can increase its accuracy and value in simulation optimization problems. Results indicate that the technique has potential in that when output post-processing was enabled the accuracy of the surrogate model increased, i.e. its output more losely matched the output of the real simulation model. No apparent improvement in optimization performance could be observed however. It was speculated that this was due to either the optimization algorithm used not taking advantage of the improved accuracy of the surrogate model, or the fact the the improved accuracy of the surrogate model was to small to make any measurable impact. Further investigation of these issues must be conducted in order to get a better understanding of the pros and cons of the technique.
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Gustafsson, Erik. "Optimization of Castings by using Surrogate Models." Licentiate thesis, Linköping University, Department of Management and Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-10192.
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In this thesis structural optimization of castings and thermomechanical analysis of castings are studied.
In paper I an optimization algorithm is created by using Matlab. The algorithm is linked to the commercial FE solver Abaqus by using Python script. The optimization algorithm uses the successive response surfaces methodology (SRSM) to create global response surfaces. It is shown that including residual stresses in structural optimization of castings yields an optimal shape that differs significantly from the one obtained when residual stresses are excluded.
In paper II the optimization algorithm is expanded to using neural networks. It is tested on some typical bench mark problems and shows very promising results. Combining paper I and II the response surfaces can be either analytical functions, both linear and non-linear, or neural networks. The optimization is then performed by using sequential linear programming or by using a zero-order method called Complex. This is all gathered in a package called StuG-OPT.
In paper III and IV focus is on the thermomechanical problem when residual stresses are calculated. In paper III a literature review is performed and some numerical simulations are performed to see where numerical simulations can be used in the industry today. In paper IV simulations are compared to real tests. Several stress lattices are casted and the residual stresses are measured. Simulations are performed by using Magmasoft and Abaqus. In Magmasoft a J2-plasticity model is used and in Abaqus two simulations are performed using either J2-plasticity or the ”Cast Iron Plasticity” available in Abaqus that takes into account the different behavior in tension and compression for grey cast iron.
Report code: LIU-TEK-LIC-2007:34.
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Nordman, Ina IC Clinical School St Vincent's Hospital Faculty of Medicine UNSW. "Surrogate endpoints of survival in metastatic carcinoma." Publisher:University of New South Wales. Clinical School - St Vincent's Hospital, 2008. http://handle.unsw.edu.au/1959.4/42791.
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In most randomised controlled trials (RCTs), a large number of patients need to be followed over many years, for the clinical benefit of the drug to be accurately quantified (1). Using an early proxy, or a surrogate endpoint, in place of the direct endpoint of overall survival (OS) could theoretically shorten the duration of RCTs and minimise the exposure of patients to ineffective or toxic treatments (2, 3). This thesis examined the relationship between surrogate endpoints and OS in metastatic colorectal cancer (CRC), advanced non-small cell lung cancer (NSCLC) and metastatic breast cancer (MBC). A review of the literature identified 144 RCTs in metastatic CRC, 189 in advanced NSCLC and 133 in MBC. The publications were generally of poor quality with incomplete reporting on many key variables, making comparisons between studies difficult. The introduction of the CONSORT statement was associated with improvements in the quality of reporting. For CRC (337 arms), NSCLC (429 arms) and MBC (290 arms) there were strong relationships between OS and progression free survival (PFS), time to progression (TTP), disease control rate (DCR), response rate (RR) and partial response (PR). Correlation was also demonstrated between OS and complete response (CR) in CRC and duration of response (DOR) in MBC. However, while strong relationships were found, the proportion of variance explained by the models was small. Prediction bands constructed to determine the surrogate threshold effect size indicated that large improvements in the surrogate endpoints were needed to predict overall survival gains. PFS and TTP showed the most promise as surrogates. The gain in PFS and TTP required to predict a significant gain in overall survival was between 1.2 and 7.0 months and 1.8 and 7.7 months respectively, depending on trial size and tumour type. DCR was a better potential predictor of OS than RR. The results of this study could be used to design future clinical trials with particular reference to the selection of surrogate endpoint and trial size.
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Mackman, Thomas James. "Surrogate model construction for steady aerodynamic loads." Thesis, University of Bristol, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.633231.
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An efficient method for predicting steady aerodynamic loads with respect to varying geometric and flow parameters is to use a surrogate model to interpolate or approximate a finite set of Computational Fluid Dynamics (CFD) simulations. Further improvements to the strategy for constructing the surrogate have the potential to provide more accurate predicted values or to reduce the number of simulations required to achieve a model of sufficient quality. This work was originally motivated by the task of providing data for calculating structural loads for civil passenger aircraft, but is directly relevant for closely related applications such as providing aerodynamic data for flight mechanics analysis, and quantification of race-car aerodynamic performance. The objective at the outset was to develop aspects toward an improved surrogate modelling strategy for predicting aerodynamic data that enables a reduction in the overall simulation budget. To this end, the fundamental topics of adaptive sampling, model parameter tuning, and practical implementation for aerodynamic data have been investigated, with the goal of developing novel methods in each of these areas, and analysing their operation. Details of an adaptive sampling method based on a combination of curvature-adaptive and space-filling components are presented, including recovery of expected behaviour for analytic functions, formulation of the space-filling component, simultaneous addition of update points; and how best to optimise the criterion efficiently for multidimensional problems. An advanced strategy for choosing locally varying interpolation parameters is then presented, which works by optimising a single value to scale a prescribed local distribution of parameters, subject to constraints on the properties of the interpolation matrix. Following this, the use of various physics-based responses to drive the sampling algorithm and techniques for mitigating noise are investigated for application to aerodynamic data.
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劉巨基 and Kui-kai Gary Lau. "Surrogate markers of atherosclerosis and cardiovascular disease." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40733749.
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Kamath, Atul Krishna. "Surrogate-assisted optimisation-based verification & validation." Thesis, University of Exeter, 2014. http://hdl.handle.net/10871/15637.
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This thesis deals with the application of optimisation based Validation and Verification (V&V) analysis on aerospace vehicles in order to determine their worst case performance metrics. To this end, three aerospace models relating to satellite and launcher vehicles provided by European Space Agency (ESA) on various projects are utilised. As a means to quicken the process of optimisation based V&V analysis, surrogate models are developed using polynomial chaos method. Surro- gate models provide a quick way to ascertain the worst case directions as computation time required for evaluating them is very small. A sin- gle evaluation of a surrogate model takes less than a second. Another contribution of this thesis is the evaluation of operational safety margin metric with the help of surrogate models. Operational safety margin is a metric defined in the uncertain parameter space and is related to the distance between the nominal parameter value and the first instance of performance criteria violation. This metric can help to gauge the robustness of the controller but requires the evaluation of the model in the constraint function and hence could be computationally intensive. As surrogate models are computationally very cheap, they are utilised to rapidly compute the operational safety margin metric. But this metric focuses only on finding a safe region around the nominal parameter value and the possibility of other disjoint safe regions are not explored. In order to find other safe or failure regions in the param- eter space, the method of Bernstein expansion method is utilised on surrogate polynomial models to help characterise the uncertain param- eter space into safe and failure regions. Furthermore, Binomial failure analysis is used to assign failure probabilities to failure regions which might help the designer to determine if a re-design of the controller is required or not. The methodologies of optimisation based V&V, surrogate modelling, operational safety margin, Bernstein expansion method and risk assessment have been combined together to form the WCAT-II MATLAB toolbox.
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Lau, Kui-kai Gary. "Surrogate markers of atherosclerosis and cardiovascular disease." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B40733749.
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Wang, Xiaolin. "Synchronous fault simulation by surrogate with exceptions." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184687.
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The contribution of this dissertation is the development of a completely new and accurate algorithm SFSSE for synchronous fault simulation of sequential circuits. The distinctive difference between SFSSE (Synchronous Fault Simulation by Surrogate with Exceptions) and similar approaches for fault simulation in combinational logic circuits is that SFSSE is capable of handling faults stored in more than one memory elements and the reconvergence over time of the stored fault effect with the original fault. The experimental result shows a significant improvement for SFSSE by comparing its execution time to that of parallel fault simulation. After a stored fault list is established during one clock period, all paths from the output of that memory element to the primary outputs might be blocked in subsequent clock periods. A fault is usually propagated through many paths in various subnetworks over several clock periods, and it is detected when only one of these paths reaches a primary output. A new idea for efficiency is suggested in the last chapter to avoid the unproductive simulation activity. In that approach the waste of simulation time is avoided by overlapping the simulation of multiple clock periods.
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Koch, Christiane. "Quantum dissipative dynamics with a surrogate Hamiltonian." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2002. http://dx.doi.org/10.18452/14816.
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Diese Dissertation untersucht Quantensysteme in kondensierter Phase, welche mit ihrer Umgebung wechselwirken und durch ultrakurze Laserpulse angeregt werden. Die Zeitskalen der verschiedenen beteiligten Prozessen lassen sich bei solchen Problemen nicht separieren, weshalb die Standardmethoden zur Behandlung offener Quantensysteme nicht angewandt werden können. Die Methode des Surrogate Hamiltonian stellt ein Beispiel neuer Herangehensweisen an dissipative Quantendynamik dar. Die Weiterentwicklung der Methode und ihre Anwendung auf Phänomene, die zur Zeit experimentell untersucht werden, stehen im Mittelpunkt dieser Arbeit. Im ersten Teil der Arbeit werden die einzelnen dissipativen Prozesse klassifiziert und diskutiert. Insbesondere wird ein Modell der Dephasierung in die Methode des Surrogate Hamiltonian eingeführt. Dies ist wichtig für zukünftige Anwendungen der Methode, z.b. auf kohärente Kontrolle oder Quantencomputing. Diesbezüglich hat der Surrogate Hamiltonian einen großen Vorteil gegenüber anderen zur Verfügung stehenden Methoden dadurch, daß er auf dem Spin-Bad, d.h. auf einer vollständig quantenmechanischen Beschreibung der Umgebung, beruht. Im nächsten Schritt wird der Surrogate Hamiltonian auf ein Standardproblem für Ladungstransfer in kondensierter Phase angewandt, zwei nichtadiabatisch gekoppelte harmonische Oszillatoren, die in ein Bad eingebettet sind. Dieses Modell stellt eine große Vereinfachung von z.B. einem Molekül in Lösung dar, es dient hier jedoch als Testbeispiel für die theoretische Beschreibung eines prototypischen Ladungstransferereignisses. Alle qualitativen Merkmale eines solchen Experimentes können wiedergegeben und Defizite früherer Behandlungen identifiziert werden. Ultraschnelle Experimente beobachten Reaktionsdynamik auf der Zeitskala von Femtosekunden. Dies kann besonders gut durch den Surrogate Hamiltonian als einer Methode, die auf einer zeitabhängigen Beschreibung beruht, erfaßt werden. Die Kombination der numerischen Lösung der zeitabhängigen Schrödingergleichung mit der Wignerfunktion, die die Visualisierung eines Quantenzustands im Phasenraum ermöglicht, gestattet es, dem Ladungstransferzyklus intuitiv Schritt für Schritt zu folgen. Der Nutzen des Surrogate Hamiltonian wird weiterhin durch die Verbindung mit der Methode der Filterdiagonalisierung erhöht. Dies gestattet es, aus mit dem Surrogate Hamiltonian nur für relative kurze Zeite konvergierte Erwartungswerten Ergebnisse in der Frequenzdomäne zu erhalten. Der zweite Teil der Arbeit beschäftigt sich mit der theoretischen Beschreibung der laserinduzierten Desorption kleiner Moleküle von Metalloxidoberflächen. Dieses Problem stellt ein Beispiel dar, in dem alle Aspekte mit derselben methodischen Genauigkeit beschrieben werden, d.h. ab initio Potentialflächen werden mit einem mikroskopischen Modell für die Anregungs- und Relaxationsprozesse verbunden. Das Modell für die Wechselwirkung zwischen angeregtem Adsorbat-Substrat-System und Elektron-Loch-Paaren des Substrats beruht auf einer vereinfachten Darstellung der Elektron-Loch-Paare als ein Bad aus Dipolen und auf einer Dipol-Dipol-Wechselwirkung zwischen System und Bad. Alle Parameter können aus Rechnungen zur elektronischen Struktur abgeschätzt werden. Desorptionswahrscheinlichkeiten und Desorptionsgeschwindigkeiten werden unabhängig voneinander im experimentell gefundenen Bereich erhalten. Damit erlaubt der Surrogate Hamiltonian erstmalig eine vollständige Beschreibung der Photodesorptionsdynamik auf ab initio-Basis.This thesis investigates condensed phase quantum systems which interact with their environment and which are subject to ultrashort laser pulses. For such systems the timescales of the involved processes cannot be separated, and standard approaches to treat open quantum systems fail. The Surrogate Hamiltonian method represents one example of a number of new approaches to address quantum dissipative dynamics. Its further development and application to phenomena under current experimental investigation are presented. The single dissipative processes are classified and discussed in the first part of this thesis. In particular, a model of dephasing is introduced into the Surrogate Hamiltonian method. This is of importance for future work in fields such as coherent control and quantum computing. In regard to these subjects, it is a great advantage of the Surrogate Hamiltonian over other available methods that it relies on a spin, i.e. a fully quantum mechanical description of the bath. The Surrogate Hamiltonian method is applied to a standard model of charge transfer in condensed phase, two nonadiabatically coupled harmonic oscillators immersed in a bath. This model is still an oversimplification of, for example, a molecule in solution, but it serves as testing ground for the theoretical description of a prototypical ultrafast pump-probe experiment. All qualitative features of such an experiment are reproduced and shortcomings of previous treatments are identified. Ultrafast experiments attempt to monitor reaction dynamics on a femtosecond timescale. This can be captured particularly well by the Surrogate Hamiltonian as a method based on a time-dependent picture. The combination of the numerical solution of the time-dependent Schrödinger equation with the phase space visualization given by the Wigner function allows for a step by step following of the sequence of events in a charge transfer cycle in a very intuitive way. The utility of the Surrogate Hamiltonian is furthermore significantly enhanced by the incorporation of the Filter Diagonalization method. This allows to obtain frequency domain results from the dynamics which can be converged within the Surrogate Hamiltonian approach only for comparatively short times. The second part of this thesis is concerned with the theoretical treatment of laser induced desorption of small molecules from oxide surfaces. This is an example which allows for a description of all aspects of the problem with the same level of rigor, i.e. ab initio potential energy surfaces are combined with a microscopic model for the excitation and relaxation processes. This model of the interaction between the excited adsorbate-substrate complex and substrate electron-hole pairs relies on a simplified description of the electron-hole pairs as a bath of dipoles, and a dipole-dipole interaction between system and bath. All parameters are connected to results from electronic structure calculations. The obtained desorption probabilities and desorption velocities are simultaneously found to be in the right range as compared to the experimental results. The Surrogate Hamiltonian approach therefore allows for a complete description of the photodesorption dynamics on an ab initio basis for the first time.
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Whiting, Brant R. "Improving Surrogate Monitoring Techniques for Suspended Sediment." DigitalCommons@USU, 2013. https://digitalcommons.usu.edu/etd/2075.
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The quality of water of our nation’s rivers and streams is important to many vital uses including drinking water treatment, recreation, and the natural environment. Water quality can be severely impacted by the quantity and type of suspended sediment found therein. Because suspended sediment can be associated with many other contaminants that degrade water quality, it is noted as the most common impairment to water quality in the United States. Suspended sediment can cause significant ecological impacts to the chemical and biological characteristics of surface waters. The ability to accurately quantify suspended sediment concentrations at the appropriate time(s) and location(s) is critical in assessing whether streams are meeting their designated beneficial uses and in implementing and evaluating watershed management and mitigation plans and restoration efforts. Currently, new methods for quantifying suspended sediment concentrations use mathematical and statistical techniques to relate turbidity and suspended sediment and have been shown to be affected by several factors, including the size and characteristics of suspended sediment particles. In this research we used turbidity as a surrogate (substitute) for suspended sediment at six locations in the Little Bear River, Utah, U.S.A. We also examined the differences between single-point and width and depth integrated suspended sediment sampling at two sites. This was used to develop a method to account for the differences and improve the resulting estimates of suspended sediment concentrations. Statistical techniques were used to assess—in probabilistic terms—the duration and magnitude of potential water quality criteria exceedance. Findings highlight that among some monitoring locations with wide geographic distances, turbiditysuspended sediment relationships are not site-specific for the more frequent (90th percentile) but lower (<50 NTU) turbidity values. Comparisons of point measures of turbidity and width and depth integrated suspended sediment samples revealed that suspended sediment is homogenous at their respective stream cross sections for 90% and 99% of the time at sites 2 and 6, respectively. The results are applicable to water managers who are charged with the determination of attainment or exceedance of water quality standards.
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Travis, Spencer Kyle, Jacob Goodin, Dylan Suarez, and Caleb D. Bazyler. "Identifying a Surrogate Measure of Weightlifting Performance." Digital Commons @ East Tennessee State University, 2017. https://dc.etsu.edu/etsu-works/5795.
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Filander, Tanian. "The enforceability of international surrogacy in South Africa : how would a South African court proceed in determining an international surrogacy case?" University of the Western Cape, 2016. http://hdl.handle.net/11394/5503.
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Magister Legum - LLMIn this research, I sought to investigate the extent to which South Africa recognises international surrogacy agreements. I examined Chapter 19 of the Children's Act as the first legislation to afford surrogate motherhood agreements legal recognition in South Africa. Section 292(1)(b)-(e) of the Children's Act sets out the requirements for the validity of a surrogate agreement. The validity of the agreement is governed by South African law if it was concluded in South Africa, and at least one of the commissioning parents and the surrogate mother and her husband or partner must be domiciled in South Africa at the time of entering into the agreement. I explored South African legislation that may be applicable to the children born of commissioning parents (whether the commissioning parents are South Africans or foreign nationals) who entered into international surrogacy agreements. I concluded that the main issue that relates to international surrogacy are the implications that rise from registering a surrogate born child’s birth in South Africa and in other countries. I further concluded that the current position of South African law will result in a surrogate born child being left stateless and parentless. I considered the criminal aspect of international surrogacy agreements as a consequence of a null and void international surrogacy agreement. Furthermore, I referred to the legal difficulties of international surrogacy and potential rights infringed on or denied to the child born of an international surrogacy by examining international case law. I concluded that South African courts do not have precedents, guidelines or legislation governing international surrogacy agreements and thus it is important to examine international case law. I further concluded that, it is important for South African authorities and courts to consider the possibility of international surrogacy occurring in South Africa. I hope that the South African courts take a child-centered approach, building on the views established in the international case law, and that courts do not adopt a strict interpretation of our current laws. Lastly, I suggested recommendations for the appropriate manner in which to legislate international surrogacy agreements in South Africa. I submitted that judicial and administrative authorities could inspect the international surrogacy agreement and ensure that the terms do not harm the child and that the child is recognised as the legal child of the commissioning parents. The courts should first look at the suitability of the commissioning parents and finally consider the best interest of the child as being of paramount importance, before ordering the international surrogacy agreement null and void. I further suggested that a statutory regulation that contemplates international surrogacy should be formulated, as a source of reference, which will assist a court when faced with determining the issue of the parentage of a surrogate born child, and consequently, his or her nationality. I concluded that the South African Parliament should either re-draft or provide clearer guidelines regarding surrogacy and the possibility of international surrogacy agreements.
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Reinders, Claudia I. "Nitric oxide : a surrogate marker of bowel inflammation /." Stockholm, 2005. http://diss.kib.ki.se/2005/91-7140-491-0/.
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Evans, Jane 1954. "Surrogate decision-making : speaking on behalf of another." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33756.
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The adult, competent patient has the ability to be involved in decisions regarding care and treatment. The critically ill patient, who is incompetent or incapacitated will be unable to speak for herself and yet, decisions will need to continue to be made. Decisions should reflect the values and beliefs of the patient. In health care we have determined that one of the best methods of preserving the autonomy of the patient through the reflection of values and beliefs is by involving a surrogate decision-maker. This thesis examines the many facets and factors that define the complex role of surrogacy. The role is described by reviewing literature on the current legal standards of decision-making, by analysing the data describing patient-surrogate preferences and the relevancy of such factors as culture and religion as facilitators or inhibitors in the decision-making process. The thesis suggests that a shared decision-making approach could provide the key to a partnership between the health care professional and the surrogates to assist in the preservation of patient autonomy.
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McKnight, J. J. "Surrogate markers in transitional cell carcinoma of bladder." Thesis, Queen's University Belfast, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.401757.
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Ooi, Boon Hooi. "Surrogate-based optimization of a BioMEMs microfluidic weir." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/45276.
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Thesis (S.M.)--Massachusetts Institute of Technology, Computation for Design and Optimization Program, 2008.Includes bibliographical references (p. 127-130).
BioMEM microfluidic weirs enable biologists to study biological processes at the cell level. A novel substrate-affixed microfluidic array of weirs allows active sorting of cells via control electrodes. The ability of the weirs to retain cells hydrodynamically is vital to the functionality of the substrate-affixed array of weirs. The objective of this thesis is to give insight using numeric tools to the microfluidic weir designer on how to improve the ability of the microfluidic weir to retain cells. Simulations of the interactions between the cell and the weir were performed using a computer simulation of Stokes flow. The computational approach uses a pre-corrected Fast Fourier Transform Boundary Element Method to evaluate the drag forces acting on the cell and a rigid body physics library to handle rigid body collision dynamics between the cell and the weir. This model was used to address two research questions which are the two main discussions of the thesis. The first discussion studies in detail the mechanisms behind the 'Around The Side' (ATS) and 'Over The Top' (OTT) modes of escape that were observed experimentally. A model example was studied for each mode. The forces and torques experienced by the cell when it escaped through either mode are explained in detail. Each mode was segmented into time periods and the mechanisms behind these modes of escape were discussed to give insight to the microfluidic weir designer. The second discussion focuses on design space exploration and optimization of the ability of the microfluidic weir to retain the cell. In order to make design optimization computationally tractable a surrogate is derived; that is, a model that provides an accurate approximation to the input/output map of the simulation but that is much cheaper computationally to evaluate.
(cont.) The surrogate was built using the Support Vector Machine (SVM) algorithm and was then used for the design space exploration and optimization. The weir geometry and flow rate were used as design variables to maximize the ability of the microfluidic weir to retain cells in the design optimization problem. Results from the design space exploration and optimization showed that a minimal depth of the mouth of the weir is required for the weir to be able to retain any beads. However, the ability of the weir to retain beads is more sensitive to the width of the mouth than the depth.
by Boon Hooi Ooi.
S.M.
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Liem, Rhea Patricia. "Surrogate modeling for large-scale black-box systems." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/41559.
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Thesis (S.M.)--Massachusetts Institute of Technology, Computation for Design and Optimization Program, 2007.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (p. 105-110).
This research introduces a systematic method to reduce the complexity of large-scale blackbox systems for which the governing equations are unavailable. For such systems, surrogate models are critical for many applications, such as Monte Carlo simulations; however, existing surrogate modeling methods often are not applicable, particularly when the dimension of the input space is very high. In this research, we develop a systematic approach to represent the high-dimensional input space of a large-scale system by a smaller set of inputs. This collection of representatives is called a multi-agent collective, forming a surrogate model with which an inexpensive computation replaces the original complex task. The mathematical criteria used to derive the collective aim to avoid overlapping of characteristics between representatives, in order to achieve an effective surrogate model and avoid redundancies. The surrogate modeling method is demonstrated on a light inventory that contains light data corresponding to 82 aircraft types. Ten aircraft types are selected by the method to represent the full light inventory for the computation of fuel burn estimates, yielding an error between outputs from the surrogate and full models of just 2.08%. The ten representative aircraft types are selected by first aggregating similar aircraft types together into agents, and then selecting a representative aircraft type for each agent. In assessing the similarity between aircraft types, the characteristic of each aircraft type is determined from available light data instead of solving the fuel burn computation model, which makes the assessment procedure inexpensive.
(cont.) Aggregation criteria are specified to quantify the similarity between aircraft types and a stringency, which controls the tradeoff between the two competing objectives in the modeling -- the number of representatives and the estimation error. The surrogate modeling results are compared to a model obtained via manual aggregation; that is, the aggregation of aircraft types is done based on engineering judgment. The surrogate model derived using the systematic approach yields fewer representatives in the collective, yielding a surrogate model with lower computational cost, while achieving better accuracy. Further, the systematic approach eliminates the subjectivity that is inherent in the manual aggregation method. The surrogate model is also applied to other light inventories, yielding errors of similar magnitude to the case when the reference light inventory is considered.
by Rhea Patricia Liem.
S.M.
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Macatula, Romcholo Yulo. "Linear Parameter Uncertainty Quantification using Surrogate Gaussian Processes." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/99411.
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We consider uncertainty quantification using surrogate Gaussian processes. We take a previous sampling algorithm and provide a closed form expression of the resulting posterior distribution. We extend the method to weighted least squares and a Bayesian approach both with closed form expressions of the resulting posterior distributions. We test methods on 1D deconvolution and 2D tomography. Our new methods improve on the previous algorithm, however fall short in some aspects to a typical Bayesian inference method.Master of Science
Parameter uncertainty quantification seeks to determine both estimates and uncertainty regarding estimates of model parameters. Example of model parameters can include physical properties such as density, growth rates, or even deblurred images. Previous work has shown that replacing data with a surrogate model can provide promising estimates with low uncertainty. We extend the previous methods in the specific field of linear models. Theoretical results are tested on simulated computed tomography problems.
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Gonçalves, Diogo Antunes. "Energy management systems based on adaptive surrogate modelling." Doctoral thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/23559.
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Doutoramento em Sistemas Energéticos e Alterações ClimáticasEstima-se que o sector dos edifícios seja responsável por cerca de 40% da totalidade de energia consumida na União Europeia e Estados Unidos da América. 50% dessa energia está alocada a sistemas de aquecimento, ventilação e ar-condicionado (AVAC), dos quais 20% estimam-se ser desperdiçados devido a ineficiência na gestão de energia. Considera-se pertinente focar-se no melhoramento da eficiência energética do edificado, reduzindo o desperdício de forma a evitar a escassez de recursos fósseis, bem como para mitigar os problemas ambientais e as alterações climáticas causadas pelo consumo e produção de energia. A tese propõe abordagens e metodologias que permitem tomar o controlo preditivo de supervisão dos sistemas de climatização enquanto medida de reabilitação energética na requalificação de edifícios. A principal contribuição deste trabalho prende-se com a implementação e desenvolvimento de metamodelos adaptativos baseados em aprendizagem computacional que assistam o processo de otimização multi-objetivo inerente ao controlo supervisor da gestão de energia em edifícios de serviços. Esta metodologia deverá ainda permitir a sua implementação de forma agnóstica a natureza dos sistemas AVAC existentes no edifício. A metodologia apresentada propõe uma abordagem convergente com o estado da arte no desenvolvimento científico na área da inteligência artificial. O esforço mínimo requerido para a implementação deste tipo de sistema de gestão inteligente e avaliado, concluindo-se que o seu potencial de aplicação e significativo. Para este fim, foi desenvolvida uma aplicação informática capaz de conduzir toda a metodologia em regime de simulação computacional de modo a averiguar a utilidade das soluções propostas pelo sistema de controlo supervisor desenvolvido. Os resultados obtidos apresentam soluções compatíveis com o melhoramento do paradigma energético-ambiental corrente, contribuindo desse modo para uma maior sustentabilidade do edificado obsoleto em termos energéticos. Os custos com energia alocada a sistemas AVAC podem alcançar uma redução de 27% dos custos base, acompanhando uma melhoria ao nível do conforto dos ocupantes. Mesmo em casos em que a requalificação da envolvente do edifício e do sistema de climatização seja anterior a implementação de um sistema de gestão inteligente, ou que a envolvente seja já competente em termos de eficiência energética (como o caso de estudo apresentado), a poupança energética e, ainda assim, assegurada devido a natureza flexível e autodidata do sistema de supervisão proposto. Portanto, recomenda-se que a reabilitação energética de edifícios tome como prioridade a requalificação do sistema de controlo AVAC por sistemas avançados e supervisores de controlo de forma a potenciarem a inércia dos edifícios, bem como toda a informação disponível na atual era digital.
Buildings account for almost 40% of the total energy consumption in the European Union and the United States combined. From that fraction, 50% is allocated to the heating, ventilation and air-conditioning systems (HVAC), from which 20% is wasted due to system's ine ciency. Considering that most of this energy is obtained from scarce fossil reserves and its consumption has an adverse impact on the climate change problem, it is of utmost importance to reduce energy wastes, namely by improving the overall energy e ciency of buildings. This thesis postulates the implementation of intelligent supervisory control systems for new or existing HVAC equipment as an energy retro tting measure concurrent with conventional architectural and systems retro tting. The proposed methodology is characterized by a exible, yet robust predictive control algorithm, capable of supervising generic HVAC systems in real-time by suggesting high-level controls, resulting in an optimized compromise between occupants' comfort requirements and energy consumption (and/or cost), taking advantage of the building constructive characteristics and information availability. The proposed solution integrates the exibility of machine learning techniques with the robustness of surrogate models to deliver data-driven predictive models capable of assisting the multi-objective optimization problem of minimizing energy consumption and cost while improving occupants comfort. The proposed modelling and optimization strategies are presented as a novelty capable of answering the quest for a robust yet exible supervisory predictive control for generic HVAC systems. A software package capable of delivering advanced and generic supervisory predictive controls, especially focusing on the scope of building energy retro tting was developed and used as the delivery method for the results presented in this thesis. The obtained results suggest that o ce buildings, characterized by a contemporary construction and HVAC system, can be improved regarding overall energy e ciency and occupants comfort by retro tting the control solution adding a supervisory predictive control level, external to the existing HVAC system. The expected energy saving by considering the proposed control are in line with the requirements imposed by the present energy and climate change framework, with up to 27% savings of energy related costs due to autonomous demand shifting. Moreover, it is recommended that building energy retro ts should consider as a priority the update of the energy control strategies by adding supervisory solutions capable of capitalizing the use of the building thermal inertia as well as the available data in this current information era (occupancy schedules, weather, etc.).
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Wang, Hui. "Response Adaptive Randomization using Surrogate and Primary Endpoints." VCU Scholars Compass, 2016. http://scholarscompass.vcu.edu/etd/4517.
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In recent years, adaptive designs in clinical trials have been attractive due to their efficiency and flexibility. Response adaptive randomization procedures in phase II or III clinical trials are proposed to appeal ethical concerns by skewing the probability of patient assignments based on the responses obtained thus far, so that more patients will be assigned to a superior treatment group. General response-adaptive randomizations usually assume that the primary endpoint can be obtained quickly after the treatment. However, in real clinical trials, the primary outcome is delayed, making it unusable for adaptation. Therefore, we utilize surrogate and primary endpoints simultaneously to adaptively assign subjects between treatment groups for clinical trials with continuous responses. We explore two types of primary endpoints commonly used in clinical tirials: normally distributed outcome and time-to-event outcome. We establish a connection between the surrogate and primary endpoints through a Bayesian model, and then update the allocation ratio based on the accumulated data. Through simulation studies, we find that our proposed response adaptive randomization is more effective in assigning patients to better treatments as compared with equal allocation randomization and standard response adaptive randomization which is solely based on the primary endpoint.
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Delimont, Isaac L. "Compliant Joints Suitable for Use as Surrogate Folds." BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/4231.
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Origami-inspired design is an emerging field capable of producing compact and efficient designs. The object of a surrogate fold is to provide a fold-like motion in a non-paper material without undergoing yielding. Compliant mechanisms provide a means to achieve these objectives as large deflections are achieved. The purpose of this thesis is to present a summary of existing compliant joints suitable for use as surrogate folds. In doing so, motions are characterized which no existing compliant joint provides. A series of compliant joints is proposed which provides many of these motions. The possibility of patterning compliant joints to form an array is discussed. Arrays capable of producing interesting motions are noted.
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Cravens, Brittany. "Surrogacy Law?: The Unparalleled Social Utility of Surrogacy and The Need for Federal Legislation." Wittenberg University Honors Theses / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=wuhonors1338487474.
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Berg, Fredrik, and Rawa Alhaider. "Surrogate boycotts : and the effects on companies and marketing." Thesis, Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-15770.
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The purpose of this research is to understand what role surrogate boycotts can play on companies targeted by a surrogate boycott and how companies can work with their marketing strategies to reduce the effects of a surrogate boycotts. We have used a qualitative approach in this thesis, with multiple cases studies as a method. Our empirical data was collected through personal interviews with people from the Danish companies: Mette Munk A/S, Nordex Foods, Quantum and Arla Foods. We conclude that the role that surrogate boycotts play on companies involved is that it effect the company’s financial situation and gives the problems with the image. We also conclude that companies can work with promotion, altering their products and choosing other ways to distribute their products in order to reduce the effects of a surrogate boycott. Also different marketing tools and strategies can be used during different stages of the boycott in order to be most effective.
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Ormandy, Shannon L. "An Experimental Demonstration of the Surrogate Conditioned Motivating Operation." Thesis, The Chicago School of Professional Psychology, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10750075.
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The present study attempted to establish a flashing or solid red light as a surrogate conditioned motivating operation (CMO-S) by pairing the light with the unconditioned motivating operation (UMO) of heat. The effects of the red light were assessed by an ABAB reversal design for three participants and an ABA reversal design for one participant. Baseline sessions consisted of presenting the red light in the absence of the UMO of heat to assess for any behavioral effects of the red light before and after pairing with the UMO of heat. Galvanic Skin Response (GSR) was recorded for all participants as an indirect measure of sweating. Additional dependent variables and the ambient temperature for each participant’s UMO of heat were identified through a temperature and response assessment. The additional dependent variable was drinking water for Participants 2–4 and throat clearing for Participant 1. Results suggest that the flashing red light may have been conditioned as a CMO-S for Participants 2 and 3. Participant 4 did not consume any water during any baseline session, suggesting that the solid red light did not function as a CMO-S after pairing. Results for Participant 1 suggests that throat clearing was controlled by additional unknown variables and was not evoked by the UMO of heat. Results potentially supporting the CMO-S should be interpreted cautiously given study limitations involving temperature control and the extent that the UMO of heat was clearly demonstrated for each participant.
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Eason, John P. "A Trust Region Filter Algorithm for Surrogate-based Optimization." Research Showcase @ CMU, 2018. http://repository.cmu.edu/dissertations/1145.
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Modern nonlinear programming solvers can efficiently handle very large scale optimization problems when accurate derivative information is available. However, black box or derivative free modeling components are often unavoidable in practice when the modeled phenomena may cross length and time scales. This work is motivated by examples in chemical process optimization where most unit operations have well-known equation oriented representations, but some portion of the model (e.g. a complex reactor model) may only be available with an external function call. The concept of a surrogate model is frequently used to solve this type of problem. A surrogate model is an equation oriented approximation of the black box that allows traditional derivative based optimization to be applied directly. However, optimization tends to exploit approximation errors in the surrogate model leading to inaccurate solutions and repeated rebuilding of the surrogate model. Even if the surrogate model is perfectly accurate at the solution, this only guarantees that the original problem is feasible. Since optimality conditions require gradient information, a higher degree of accuracy is required. In this work, we consider the general problem of hybrid glass box/black box optimization, or gray box optimization, with focus on guaranteeing that a surrogate-based optimization strategy converges to optimal points of the original detailed model. We first propose an algorithm that combines ideas from SQP filter methods and derivative free trust region methods to solve this class of problems. The black box portion of the model is replaced by a sequence of surrogate models (i.e. surrogate models) in trust region subproblems. By carefully managing surrogate model construction, the algorithm is guaranteed to converge to true optimal solutions. Then, we discuss how this algorithm can be modified for effective application to practical problems. Performance is demonstrated on a test set of benchmarks as well as a set of case studies relating to chemical process optimization. In particular, application to the oxycombustion carbon capture power generation process leads to significant efficiency improvements. Finally, extensions of surrogate-based optimization to other contexts is explored through a case study with physical properties.
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Mühlenberend, Sandra. "Surrogate der Natur die historische Anatomiesammlung der Kunstakademie Dresden." Paderborn München Fink, 2004. http://deposit.ddb.de/cgi-bin/dokserv?id=2805963&prov=M&dok_var=1&dok_ext=htm.
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Tsuga, Toshihiro. "Multi-objective optimization of blast simulation using surrogate model." Fairfax, VA : George Mason University, 2007. http://hdl.handle.net/1920/2916.
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Thesis (M.S.)--George Mason University, 2007.Title from PDF t.p. (viewed Jan. 22, 2008). Thesis director: Rainald Löhner. Submitted in partial fulfillment of the requirements for the degree of Master of Science in Computational Sciences and Informatics. Vita: p. 49 Includes bibliographical references (p. 44-48). Also available in print.
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Mühlenberend, Sandra. "Surrogate der Natur : die historische Anatomiesammlung der Kunstakademie Dresden /." Paderborn : Fink, 2007. http://deposit.ddb.de/cgi-bin/dokserv?id=2805963&prov=M&dok_var=1&dok_ext=htm.
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Khan, Maryam. "Validation of Surrogate Outcomes: Application to Biomarkers of Atherosclerosis." Thèse, Université d'Ottawa / University of Ottawa, 2011. http://hdl.handle.net/10393/19963.
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Statement of the problem: Many methods for surrogate outcome validation require individual patient data which is often inaccessible by clinical trialists. Methods: A review was performed to identify statistical methods for surrogate outcome validation that may be implemented using summary data from published clinical trials. The methods were used to evaluate carotid intima-media thickness (CIMT) as a surrogate outcome for cardiovascular events in a systematic review of randomized trials of interventions for atherosclerosis. Results: the review of methods identified five procedures. At two or more years of follow-up, there was a marginally significant association of CIMT with myocardial infarction and a statistically significant association with cardiovascular mortality. At ≥ four years of follow-up, a statistically significant, negative relationship was observed between CIMT and stroke. Conclusions: CIMT may be a valid surrogate outcome for myocardial infarction and cardiovascular mortality. Additional data is needed to evaluate CIMT in specific drug classes.
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Prieß, Malte [Verfasser]. "Surrogate-Based Optimization for Marine Ecosystem Models / Malte Prieß." Kiel : Universitätsbibliothek Kiel, 2012. http://d-nb.info/1025371062/34.
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Canipa, Steven James. "Catalytic asymmetric synthesis using (-)-sparteine and the (+)-sparteine surrogate." Thesis, University of York, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.533539.
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Cross, Kathryn Mary Louise. "Studies on nicotinic acetylcholine receptors expressed in surrogate cells." Thesis, University of Southampton, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295914.
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