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Prediction Of The Behaviors Of Hollow/Foam-Filled Axially Loaded Steel/Composite Hat Sections For Advanced Vehicle Crash Safety DesignHaorongbam, Bisheshwar 11 1900 (has links) (PDF)
Hat sections, single and double, made of steel are frequently encountered in automotive body structural components such as front rails, B-Pillar, and rockers of unitized-body cars. These thin-walled components can play a significant role in terms of crashworthiness and impact energy absorption, through a nonlinear phenomenon called as progressive dynamic buckling. As modern vehicle safety design relies heavily on computer-aided engineering, there is a great need for analysis-based predictions to yield close correlation with test results. Although hat sections subjected to axial loading have been studied widely in the past, there is scanty information in published literature on modeling procedures that can lead to robust prediction of test responses. In the current study, both single-hat and double-hat components made of mild steel are studied extensively experimentally and numerically to quantify statistical variations in test responses such as peak load, mean load and energy absorption, and formulate modeling conditions for capturing elasto-plastic material behavior, strain rate sensitivity, spot-welds, etc. that can lead to robust predictions of force-time and force-displacement histories as well as failure modes. In addition, keeping initial stages of vehicle design in mind, the effectiveness of soft computing techniques based on polynomial regression analysis, radial basis functions and artificial neural networks for quick assessment of the behaviors of steel hat sections has been demonstrated. The study is extended to double-hat sections subjected to eccentric impact loading which has not been previously reported. A lightweight enhancement of load carrying capacity of steel hat section components has been investigated with PU (polyurethane) foam-filled single and double hat sections, and subjecting the same to quasi-static and axial impact loading. Good
predictions of load-displacement responses are again obtained and shortening of fold lengths vis-à-vis hollow sections is observed. Finally, the performance of hat sections made of glass fiber-reinforced composites is studied as a potential lightweight substitute to steel hat section components. The challenging task of numerical prediction of the behaviors of the composite hat sections has been undertaken using a consistent modeling and analysis procedure described earlier and by choosing an appropriate constitutive behavior available in the popular explicit contact-impact analysis solver, LS-DYNA.
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Calcination d’oxalates mixtes U-Ce : Evolution des caractéristiques des poudres et cinétique de décomposition. / Calcination of mixed U-Ce oxalates : Powders characteristics evolution and decomposition kinetics.Venturin, Agustina 03 February 2015 (has links)
Le recyclage du combustible nucléaire passe par la production de poudres d’oxydes mixtes (U,Pu)O₂. Un des principaux procédés utilisés pour obtenir ce type de poudre comporte une étape de calcination d’oxalates mixtes qui se décomposent en oxyde. Le contrôle des propriétés physico-chimiques de la poudre au cours du traitement thermique des oxalates (étape précédant la mise en forme des pastilles combustibles) requiert une attention particulière, car celles-ci auront une conséquence directe sur l’aptitude à la compaction et au frittage.Dans ce contexte, ces travaux traitent de l’évolution des caractéristiques des poudres, et de la cinétique des différentes étapes de décomposition les influençant, lors de la calcination des oxalates mixtes U-Ce (simulant U-Pu).Une étude expérimentale détaillée sur les caractéristiques morphologiques et texturales, notamment la surface spécifique, a été menée et a permis de dresser un schéma d’évolution de la poudre lors des différentes étapes de décomposition. De plus, les variations de la teneur en carbone au cours de la calcination ont aussi été étudiées. Ce travail a permis d’identifier les étapes de décomposition d’intérêt pour le contrôle des caractéristiques des poudres lors du procédé de calcination.Enfin, ces étapes réactionnelles d’intérêt ont fait l’objet d’une étude cinétique détaillée. Celle-ci a conduit à l’identification de modèles adaptés au système d’étude qui décrivent les phénomènes physiques et chimiques ayant lieu au cours de la décomposition. / Nuclear fuel recycling process includes production of mixed oxide powder as (U,Pu)O₂. One of the most common processes actually investigated to get this kind of powder involves a calcination step of mixed oxalate which decomposes in oxide products. Physical and chemical powder characteristics during oxalate heat treatment (taking place before pellet shaping step) need a special attention. In fact, powder properties can affect directly their sintering and compaction abilities.The aim of this work deals with the powder characteristics evolution and the decomposition kinetics of steps having an effect on them, during U-Ce mixed oxalate calcination (surrogate system of U-Pu couple).A detailed experimental study of morphological and textural characteristics, especially specific surface area, has been carried out. The results have enabled to achieve a textural evolution pattern during different steps of oxalate decomposition. Moreover, carbon content variations through heat treatment process have been studied. This experimental route point out the most interesting decomposition steps impacting powder characteristics during calcination.Finally, a kinetic study of these decomposition steps has been performed. This exercise led to suitable kinetic models describing physical and chemical phenomena taking place during oxalate thermal decomposition process.
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Detección de opinion spam usando PU-learningHernández Fusilier, Donato 20 July 2016 (has links)
[EN] Abstract
The detection of false or true opinions about a product or service has become nowadays a very important problem. Recent studies show that up to 80% of people have changed their final decision on the basis of opinions checked on the web. Some of these opinions may be false, positive in order to promote a product/service or negative to discredit it.
To help solving this problem in this thesis is proposed a new method for detection of false opinions, called PU-Learning*, which increases the precision by an iterative algorithm. It also solves the problem of lack of labeled opinions.
To operate the method proposed only a small set of opinions labeled as positive and another large set of opinions unlabeled are needed. From this last set, missing negative opinions are extracted and used to achieve a two classes binary classification. This scenario has become a very common situation in the available corpora.
As a second contribution, we propose a representation based on n-grams of characters. This representation has the advantage of capturing both the content and the writing style, allowing for improving the effectiveness of the proposed method for the detection of false opinions.
The experimental evaluation of the method was carried out by conducting three experiments classification of opinions, using two different collections. The results obtained in each experiment allow seeing the effectiveness of proposed method as well as differences between the use of several types of attributes.
Because the veracity or falsity of the reviews expressed by users becomes a very important parameter in decision making, the method presented here, can be used in any corpus where you have the above characteristics. / [ES] Resumen
La detección de opiniones falsas o verdaderas acerca de un producto o servicio, se ha convertido en un problema muy relevante de nuestra 'época. Según estudios recientes hasta el 80% de las personas han cambiado su decisión final basados en las opiniones revisadas en la web. Algunas de estas opiniones pueden ser falsas positivas, con la finalidad de promover un producto, o falsas negativas para desacreditarlo.
Para ayudar a resolver este problema se propone en esta tesis un nuevo método para la detección de opiniones falsas, llamado PU-Learning modificado. Este método aumenta la precisión mediante un algoritmo iterativo y resuelve el problema de la falta de opiniones etiquetadas.
Para el funcionamiento del método propuesto se utilizan un conjunto pequeño de opiniones etiquetadas como falsas y otro conjunto grande de opiniones no etiquetadas, del cual se extraen las opiniones faltantes y así lograr una clasificación de dos clases. Este tipo de escenario se ha convertido en una situación muy común en los corpus de opiniones disponibles.
Como una segunda contribución se propone una representación basada en n-gramas de caracteres. Esta representación tiene la ventaja de capturar tanto elementos de contenido como del estilo de escritura, permitiendo con ello mejorar la efectividad del método propuesto en la detección de opiniones falsas.
La evaluación experimental del método se llevó a cabo mediante tres experimentos de clasificación de opiniones utilizando dos colecciones diferentes. Los resultados obtenidos en cada experimento permiten ver la efectividad del método propuesto así como también las diferencias entre la utilización de varios tipos de atributos.
Dado que la falsedad o veracidad de las opiniones vertidas por los usuarios, se convierte en un parámetro muy importante en la toma de decisiones, el método
que aquí se presenta, puede ser utilizado en cualquier corpus donde se tengan las características mencionadas antes. / [CAT] Resum
La detecció d'opinions falses o vertaderes al voltant d'un producte o servei s'ha convertit en un problema força rellevant de la nostra època. Segons estudis recents, fins el 80\% de les persones han canviat la seua decisió final en base a les opinions revisades en la web. Algunes d'aquestes opinions poden ser falses positives, amb la finalitat de promoure un producte, o falses negatives per tal de desacreditarlo.
Per a ajudar a resoldre aquest problema es proposa en aquesta tesi un nou mètode de detecció d'opinions falses, anomenat PU-Learning*. Aquest mètode augmenta la precisió mitjançant un algoritme iteratiu i resol el problema de la falta d'opinions etiquetades.
Per al funcionament del mètode proposat, s'utilitzen un conjunt reduït d'opinions etiquetades com a falses i un altre conjunt gran d'opinions
no etiquetades, del qual se n'extrauen les opinions que faltaven i, així, aconseguir una classificació de dues classes. Aquest tipus d'escenari s'ha convertit en una situació molt comuna en els corpus d'opinions de què es disposa.
Com una segona contribució es proposa una representació basada en n-gramas de caràcters. Aquesta representació té l'avantatge de capturar tant elements de contingut com a d'estil d'escriptura, permetent amb això millorar l'efectivitat del mètode proposat en la detecció d'opinions falses.
L'avaluació experimental del mètode es va dur a terme mitjançant tres experiments de classificació d'opinions utilitzant dues coleccions diferents. Els resultats obtingut en cada experiment permeten veure l'efectivitat del mètode proposat, així com també les diferències entre la utilització de varis tipus d'atributs.
Ja que la falsedat o veracitat de les opinions vessades pels usuaris es converteix en un paràmetre molt important en la presa de decisions, el mètode que ací es presenta pot ser utilitzat en qualsevol corpus on es troben les característiques abans esmentades. / Hernández Fusilier, D. (2016). Detección de opinion spam usando PU-learning [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/61990 / TESIS
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En jämförande studie av konventionellt och veganskt läder : Med hänsyn till ekonomi, funktionella egenskaper, miljö och etik / A comparative study of conventional and vegan leatherKågström, Lukas, Cederberg, Anton January 2020 (has links)
Läderindustrin har funnits i flera århundraden och läder används ofta tack vare materialets slitstarka egenskaper. De senaste åren har kunskapen och även intresset kring hållbarhet och djurs rättigheter ökat. Detta har lett till ökande efterfrågan på veganska alternativ till läder. Begreppet “veganskt läder” definieras som alla läderimiterade material tillverkade utan animalistiska produkter. Det vanligaste veganska lädret är PU-läder, tillverkat av polyuretan. Piñatex är ett nonwoven-material tillverkat av ananasblad som annars brukar brännas. Reishiär ett material producerat av företaget MycoWorks, tillverkat av mycel; den vegetativa delen hos svamp. Syftet med studien är att analysera kromgarvat och vegetabiliskt garvat läder med deras veganska substitut, PU-läder, Piñatex och Reishi utifrån fyra olika parametrar; ekonomi, hållbarhet, funktionella egenskaper och djuretik. Studiens resultat visar att kromgarvat läder är det starkaste materialet, men det har även stornegativ påverkan på miljön. Anledningen till att PU-läder är det vanligaste veganska lädret är på grund av de låga produktionskostnaderna, detta avspeglas på materialets lågt presterandefunktionella egenskaper. Reishi är ett mycket innovativt material, med minst miljöpåverkan och bra egenskaper. Med stigande efterfrågan finns stort potential till att materialet kan utvecklas och användas i fler sammanhang. Ur ett djuretiskt perspektiv kan inte konventionellt läder vinna över veganskt läder. Produktionen av veganskt läder kräver inte direkt att några djur slaktas, men veganskt läder är inte helt utan negativ miljöpåverkan. Slutligen faller valet av material och dess etiska värde till var enskild individ och slutproduktens önskade egenskaper. / The leather industry has been around for centuries and leather is frequently used due to the materials durable qualities. In the past few years environmental responsibility and interest in the wellbeing of animals has increased. This has led to an increase in demand for vegan substitutes for leather. Vegan leather is defined as any leather imitating material that is produced completely without animal products. The most commonly used vegan leather today is polyurethane leather, also known as pleather. Piñatex is a nonwoven fabric produced by pineapple leaves which would otherwise be discarded. Reishi is a material produced by the company MycoWorks, made from fine mycelium, the vegetative part of a fungus. The purpose of this study is to analyze chrome tanned leather and vegetable tanned leather with their vegan counterparts, pleather, Piñatex and Reishi from four different perspectives; economic, environmental, functional and ethical perspectives. The result of the study shows that chrome tanned leather is by far the most durable of the materials, but it also has a high, negative environmental impact. The reason pleather is the most common vegan leather, is the low production cost of the fabric. This is mirrored by the low performance qualities of the fabric. Reishi is an incredibly innovative material, having the lowest environmental impact and with growing demand, the fabric has great potential to evolve and become more frequently used. Ethically speaking, vegan leather has an advantage over conventional leather, since no animals are harmed in the production process, but vegan leather is not without environmental impact. Ultimately, the choice and ethical value of each fabric comes down to the consumer and the desired qualities of the intended product.
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Regulace transkripce mikroRNA klastru miR-17-92 v průběhu diferenciace makrofágů. / Transcriptional regulation of miR-17-92 microRNA cluster during macrophage differentiation.Rybářová, Jana January 2010 (has links)
miR-17-92 cluster (Oncomir1) encodes seven microRNAs (miRNA, miR) regulating many biological processes including proliferation, differentiation or apoptosis. Overexpression of microRNAs encoded by miR-17-92 cluster is found in a number of tumors including acute and chronic myeloid leukemias (Dixon-McIver et al., 2008; Li et al., 2008; Venturini et al., 2007). Myeloid progenitors express miR-17-92 cluster at a high level, while macrophage differentiation associates with its downregulation. Our laboratory found, that miR-17-92 cluster is repressed by transcription factor Early growth response 2 (Egr2) upon differentiation of primary myeloid PUER progenitors, induced with transcription factor PU.1. Aim of this thesis is to further test the abovementioned data by preparing a reporter vectors set, carrying various fragments of miR-17-92 putative promoter, which enables us to study regulation of transcription of miR-17-92 cluster. This task complicated by presence of increased GC content of the miR-17-92 promoter was successfully accomplished resulting in amplification of eight fragments containing the various parts of miR-17-92 promoter including region -3.3 to 0 kb relative to the start of miR-17-5p sequence, that were inserted into pGL3 reporter vector. Transfection of pGL3 reporter vector carrying...
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Judge and Jurisconsult - Coercive and Persuasive Authority in Islamic LawSamour, Nahed 06 May 2021 (has links)
Judge and Jurisconsult – Coercive and Persuasive Authority in Islamic Law
(Richter und Rechtsberater- Zwingende und überzeugende Autorität im Islamischen Recht)
Wer spricht das Recht in der islamischen Rechtsprechung? Die islamische Rechtsgeschichte konzentrierte sich lange auf den Einzelrichter (qadi) als Inbegriff der Rechtsprechung. Der Richter handelte jedoch nicht als einzige Verkörperung der Rechtsprechung. Ein Justizpersonal unterstützte seine und arbeitete von einer ihm unterstellten Position aus. Darüber hinaus hat der gelehrte Rechtsberater (mufti) die Rechtsprechung durch übereinstimmende und abweichende Meinungen vor Gericht in vielerlei Hinsicht geprägt. Die Arbeit konzentriert sich auf zwei Autoritäten am Gericht – qadi und mufti – in der frühen Abbasidischen Rechtsgeschichte (2. und 3. Jahrhundert nach der islamischen Zeitrechnung bzw. 8. und 9. Jahrhundert der gregorianischen Zeit), die miteinander kooperiert oder auch konkurriert haben. Die Grundlage ihrer Beziehung ist das islamische Prinzip der gerichtlichen Beratung von Experten in Rechtsfragen. Die islamische Rechtslehre ermutigt einen Richter, der mit Rechtsunsicherheiten konfrontiert war, einen gelehrten Rechtsberater (mufti) zu konsultieren, bevor er eine gerichtliche Entscheidung trifft. Die islamische Rechtsprechung entstand somit aus einem Verhältnis von Kooperation, Konfrontation und Kooptation zwischen Richtern und (außer-gerichtlichen) gelehrten Rechtsberatern. / Judge and Jurisconsult – Coercive and Persuasive Authority in Islamic Law
Who dispenses justice at court? Islamic legal historians have long focused on the single judge (qadi) as the embodiment of the administration of justice. The judge, however, did not act alone in dispensing justice. A judicial staff supported his work, working from a position subordinate to him. In addition, evading a clearly demarcated judicial hierarchy, the learned jurisconsult (mufti) shaped adjudication in many distinct ways through concurring and dissenting opinions at court. This contribution focuses on two authorities—the qadi and the mufti—who cooperated or competed with each other at court in early Abbasid legal history (2nd-3rd century A. H. / 8th-9th century C.E.). Fundamental to their relationship is the Islamic principle of judicial consultation of experts on legal questions. Islamic legal doctrine encouraged a judge confronted with legal uncertainties to consult a mufti before issuing a judicial decision. Islamic adjudication thus emerged out of cooperation, confrontation and cooptation between judge and (extra-judicial) legal experts.
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Die außergerichtliche Restrukturierung durch den acuerdo de refinanciaciónde Ponte, Lucas 14 April 2022 (has links)
Mit dem Ausbruch der Weltwirtschaftskrise 2008/2009 begann in Spanien eine über ein Jahrzehnt andauernde Reform des Konkursrechts mit dem Fokus die außergerichtlichen Restrukturierungsinstrumente im Geiste der Zeit zu stärken. Im Zentrum dieser Reformen stand der acuerdo de refinanciación - die sog. Refinanzierungsvereinba-rung - die durch verschiedene Schutzmechanismen und Privilegien den frühen Zugang zu einer außergerichtlichen Restrukturierung ermöglichen und damit für sanierungsfähige Unternehmen den Gang zu dem kostspieligen und oft wenig erfolgsversprechenden Konkursverfahren vermeiden sollte. Das Werk untersucht dieses Instrument auf seine Kohärenz und Praxistauglichkeit und entwickelt auf der Grundlage verbleibender Regelungslücken und Fehl-einschätzungen Verbesserungsvorschläge, die einen Beitrag für zukünftige Reformdebatten leisten soll. Der Ver-fasser gelangt zu dem Ergebnis, dass das spanische Konkursrecht ein Paradigmenwechsel vollzogen hat und trotzdem noch einen weiten Weg bis zu einem in der Praxis erfolgreichen Restrukturierungsrecht gehen muss. / With the onset of the global economic crisis in 2008/2009, Spain embarked on a decade-long reform of its bank-ruptcy laws with a focus on strengthening out-of-court restructuring instruments in the spirit of the times. At the center of these reforms was the acuerdo de refinanciación - the so-called refinancing agreement - which was intended to provide early access to out-of-court restructuring through various protective mechanisms and privi-leges, thereby avoiding the need for companies capable of restructuring to go through the costly and often unprom-ising bankruptcy proceedings. The work examines this instrument in terms of its coherence and practicality and, on the basis of remaining regulatory gaps and misconceptions, develops proposals for improvement that are in-tended to contribute to future debates on reform. The author concludes that Spanish bankruptcy law has undergone a paradigm shift, but still has a long way to go to achieve a restructuring law that is successful in practice.
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Transcription factor regulation of T helper subset functionAwe, Olufolakemi O. 01 May 2015 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The immune system protects the body from foreign organisms. T cells and B cells are integral components of the ability of the immune system to generate focused immune responses. The development of specialized subsets of T helper cells is governed by transcription factors. Previous work demonstrated a requirement for the transcription factor PU.1 in the development of IL-9-secreting Th9 cells. Work in this dissertation demonstrates that the Th9 subset is not stable in vitro, and that PU.1 expression decreases during long-term culture. To examine a role for PU.1 in Th9-independent immunity we examined a model of multiple sclerosis termed experimental autoimmune encephalomyelitis (EAE). Mice that lack PU.1 expression in T cells (Sfpi1lck-/- mice) demonstrated more severe disease with attenuated recovery compared to control mice, and this was accompanied by an increase of T cells in the central nervous system. We also observed that following multiple routes of immunization Sfpi1lck-/- mice had increased numbers of T follicular helper (Tfh) cells and increased germinal center responses. This correlated with increased expression of the cytokine IL-21 and the surface protein CD40L in T cells that lacked PU.1 expression and resulted in increased numbers of germinal center B cells and antigen-specific antibody titers compared to control mice. The increased germinal center B cells and antibody titers were attenuated with blocking CD40L antibody but not with neutralizing IL-21 antibody. These results suggest that PU.1 limits the expression of CD40L on Tfh cells to regulate the humoral immune response. Together, the data in this dissertation demonstrate Th9-independent functions of PU.1. Moreover, this work shows that transcription factors promoting the development of one subset of T helper cells can simultaneously have negative effects on distinct T cell lineages.
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Hochverzweigte Polyesterole und deren Abmischungen für den Einsatz in Polyurethan-SchaumstoffenZiemer, Antje 04 June 2003 (has links)
Auf Grundlage der beiden Monomere (2,2-Bis(hydroxymethyl)propansäure (1) und 4,4-Bis(4-hydroxyphenyl)valeriansäure (2)) wurden hochverzweigte Polyester synthetisiert. Durch Verwendung von zwei-, drei-, vier- und sechsfunktionalen Kernmolekülen konnte die strukturelle Vielfalt der hochverzweigten Polyester erhöht werden. Abmischungen auf der Grundlage zweier Polyole (Polyether- bzw. Esterdiol) mit verschiedenen hochverzweigten Polyestern wurden hinsichtlich ihrer Mischbarkeit mittels DSC- und DMA-Messungen sowie rheologisch, mittels temperaturabhängiger IR-Spektroskopie, hinsichtlich ihrer Oberflächenspannung und mittels temperaturabhängiger AFM-Messungen bzw. SAXS-Messungen charakterisiert. DSC und DMA-Messungen des Glasübergangszustandes der Abmischungen gaben Hinweise, dass hochverzweigte Polyester unterschiedlicher Strukturen mit den Polyolen auf molekularer Ebene mischbar sind. Die hochverzweigten Polyester P1 und P1-PEG400 verbesserten die Verarbeitungseigenschaften eines geschlossenzelligen PU-Hartschaumstoffes. Durch die Hochfunktionalität der hochverzweigten Polyester erfolgte das Aushärten des Schaumstoffes schneller, wobei überraschenderweise das "Fließen" des Schaumstoffes gleichzeitig verbessert werden konnte. Durch den Zusatz der genannten hochverzweigten Polyester zu dem Polyetherpolyol konnte die Viskosität gesenkt werden, was die Fließeigenschaften des Schaumstoffes verbessert. Die Schaumstoffe zeigen weiterhin verbesserte mechanische Eigenschaften.
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論浦東新區的環境衛生管理模式章燦鋼 January 2003 (has links)
University of Macau / Faculty of Social Sciences and Humanities / Department of Government and Public Administration
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