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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
701

Theory and Application of Damping in Jointed Structures

Mathis, Allen, MATHIS 28 June 2019 (has links)
No description available.
702

A note on the second derivatives of rHCT basis functions

Weise, Michael January 2014 (has links)
We consider reduced Hsieh-Clough-Tocher basis functions with respect to a splitting into subtriangles at the barycenter of the original triangular element. This article gives a proof that the second derivatives of those functions, which in general may jump at the subtriangle boundaries, do not jump at the barycenter.:1 Introduction 2 Shape functions 3 Transformation of second derivatives 4 Second derivatives at the barycenter
703

Simplified calculation of rHCT basis functions for an arbitrary splitting

Weise, Michael January 2015 (has links)
Reduced Hsieh-Clough-Tocher elements are triangular C1-elements with only nine degrees of freedom. Simple formulas for the basis functions of reduced Hsieh-Clough-Tocher elements based on the edge vectors of the triangle have been given recently for a barycentric splitting. We generalise these formulas to the case of an arbitrary splitting point.:1 Introduction 2 Basic definitions 3 Mapping to the reference triangle 4 Construction of the rHCT shape functions
704

A note on the second derivatives of rHCT basis functions - extended

Weise, Michael January 2015 (has links)
We consider reduced Hsieh-Clough-Tocher basis functions with respect to a splitting into subtriangles at an arbitrary interior point of the original triangular element. This article gives a proof that the second derivatives of those functions, which in general may jump at the subtriangle boundaries, do not jump at the splitting point.:1 Introduction 2 Shape functions 3 Transformation of second derivatives 4 Second derivatives at the splitting point
705

Modeling diesel combustion in heavy duty engine using detailed chemistry approach and CFD

Duyar, Serkan January 2014 (has links)
Emission and fuel consumption are among the key parameters when designing a combustion system. Combustion CFD can assist in this task only if good enough accuracy is achieved regarding combustion and emission predictions. The aim of this master thesis is to evaluate the use of detailed reaction mechanisms (as a substitute for standard combustion model) in terms of computational time and result accuracy. Several mechanisms for n-heptane are tested. Lund University optical engine experimental case is used for this evaluation.Results showed that detailed chemistry can predict ignition accurately but differences are observed in the peak cylinder pressure. The computational time also increased significantly as size and complexity of the mechanism increased. Recommendations are given to improve predictions using detailed chemistry approach which is found to be an interesting approach especially for lift-off length predictions.
706

Accepterat pris: -En studie om bakgrunden till införandet och om syftet uppnåtts och hålls än idag? / Accepted price: -A study of background to the introduction and the purpose achieved and if maintained today?

Bergroth, Carl-Henrik, Karlsson, Zandra January 2014 (has links)
The great debate topic in media and among real estate agents in spring 2011 was specially reduced prices. Specially reduced prices means that a property is advertised at a considerably lower price than the evaluated current market value of the property. This is to attract more bidders in a potential bidding. It is in this case not completely established by law what is meant by considerably lower price, why this concept is difficult to interpret. Real estate agents got lot of criticism due to the output prices which were too low compared to the final prices. The real estate agents industry’s reputation became worse and to counter this, there was formed a taskforce of real estate agents in Stockholm. This resulted in that instead of making use of a starting price the concept of accepted price was introduced. The accepted price meant that the price that was advertised was going to be at such a level that the seller was willing to sell the property for that. With the free trial right the seller would not be compelled to sell anyhow. This study is about accounting for the emergence of accepted price and the factors behind the introduction and the concept. It also aims to clarify what the goal of accepted price was and to discuss if specially reduced prices are coming back. Finally to investigate if there can be some underlying factors that can contribute to that our perception increases as specially reduced prices. The results of the paper show that one of the ideas behind the introduction of the accepted price was to strengthen the real estate agent industry's reputation and increase transparency to bidders so they would get a further idea of the final price of the property already at the announcement. According to the interviews made with the real estate agents, it is noticed a certain tendency that specially reduced prices are considered to be on the way back. Although the collected statistics shows that such could be the case when the difference between starting- and final price has recently increased. To be able to make a more definite conclusion, this is something that could be considered when more data have been collected over a wider time frame in the future. / Våren 2011 var det stora debattämnet i media, bland konsumenter och hos fastighetsmäklare lockpriser. Med lockpris avses att en bostad annonseras till ett väsentligt lägre pris än det bedömda marknadsvärdet på bostaden. Motivet var att locka till sig fler spekulanter till en eventuell budgivning. Innebörden av väsentligt är inte helt fastställt i lagen, vilket gör begreppet svårtolkat. I och med att utgångspriserna var satta så lågt jämfört med vad slutpriset blev så fick fastighetsmäklarna utstå mycket kritik. Mäklarbranschens anseende försämrades, och för att motverka detta bildades en arbetsgrupp av fastighetsmäklare från olika mäklarföretag i Stockholms innerstad. Detta mynnade ut i att istället för att använda sig av ett utgångspris så infördes begreppet accepterat pris. Ett accepterat pris innebär att det pris som annonseras ska vara på en sådan nivå att säljaren kan tänka sig att sälja bostaden till det priset. Dock med den kvarstående fria prövningsrätten som säljaren oavsett har, som innebär att tvång till försäljning inte råder, trots inkommit bud på annonserat pris. Som säljare har du rätt att sälja när du vill, till vem du vill och till vilket pris du vill. Syftet med uppsatsen är att redogöra för överenskommelsen av accepterat pris, vilka de bakomliggande faktorerna var vid införandet och vad målet var. Vidare vill vi klargöra om lockpriser är på väg tillbaka och utreda vilka andra bakomliggande faktorer som kan bidra till att ett pris uppfattas som lockpris. Resultatet av uppsatsen visar att en av tankarna bakom införandet av accepterat pris var att stärka mäklarbranschens anseende och öka transparensen till spekulanterna då dem skulle få en bättre uppfattning om bostadens slutpris redan vid annonseringen av objektet. Enligt de gjorda intervjuerna med mäklare så märks en viss tendens till att lockpriserna anses vara på väg tillbaka. Även den inhämtade statistiken visar att så skulle kunna vara fallet då skillnaden mellan accepterat pris/utgångspris och slutpris på senare tid har ökat. För att kunna dra någon mer definitiv slutsats är detta något man bör ta ställning till när mer data har insamlats över ett större tidsperspektiv framåt i tiden.
707

Direct simulation and reduced-order modeling of premixed flame response to acoustic modulation

Qiao, Zheng 13 May 2022 (has links) (PDF)
This dissertation introduces a general, predictive and cost-efficient reduced-order modeling (ROM) technique for characterization of flame response under acoustic modulation. The model is built upon the kinematic flame model–G-equation to describe the flame topology and dynamics, and the novelties of the ROM lie in i) a procedure to create the compatible base flow that can reproduce the correct flame geometry and ii) the use of a physically-consistent acoustic modulation field for the characterization of flame response. This ROM addresses the significant limitations of the classical kinematic model, which is only applicable to simple flame configurations and relies on ad-hoc models for the modulation field. The ROM is validated by considering the acoustically-excited premixed methane/air flames in conical and M-shape configurations. To test the model availability to practical burners, a confined flame configuration is also employed for model evaluation. Furthermore, to investigate the generality of the ROM to the burner flame, the performance of the ROM with respect to the V-shape and the swirled V-shape is investigated. The model accuracy is evaluated concerning flame geometrical features and flame describing function, and assessed by comparing the ROM results with both experimental measurements and direct- numerical-simulation results. It is found that the flame describing/transfer functions predicted by the ROM compare well with reference data, and are more accurate than those obtained from the conventional kinematic model built upon heuristically-presumed modulation fields.
708

Advanced Algorithms for Virtual Reconstruction and Finite Element Modeling of Materials with Complex Microstructures

Yang, Ming January 2021 (has links)
No description available.
709

Model Reduction of Computational Aerothermodynamics for Multi-Discipline Analysis in High Speed Flows

Crowell, Andrew R. 08 August 2013 (has links)
No description available.
710

Reduced Model Analysis of Performing Arts Programming at the Massachusetts Museum of Contemporary Art, 2002-2005

Andrews, Krista M. 02 September 2008 (has links)
No description available.

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