• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 5
  • 4
  • 4
  • 4
  • 3
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 26
  • 26
  • 7
  • 7
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 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.
11

”Bra fråga, jättebra fråga…” : En kvalitativ studie av en lärares uppföljningar för stöttning i ett flerspråkigt klassrum. / ”Good question, very good question” : A qualitative study of a teacher’s follow-ups for support in a multilingual classroom.

Linda, Julien January 2022 (has links)
Syftet med föreliggande studie är att undersöka om och isåfall hur lärare på språkintroduktionsprogrammet i sin undervisning stöttar flerspråkiga elevers interaktion på målspråket genom uppföljningar. Metoden för studien grundar sig i två modeller: Exchange Structure Model av Sinclair & Coulthard (1975) och interaktionell stöttning av Hammond & Gibbons (2005). Data samlades in i form av ljudinspelningar och klassrumsobservationer på språkintroduktionsprogrammet. Resultatet visar att läraren i interaktionen med flerspråkiga elever med begränsade språkliga kunskaper använder sig av stöttande drag genom kopplingar till tidigare erfarenheter, sammanfattningar, metakommentar, approprieringar, omformuleringar, antydande eliciteringar  och framåtriktningar. Undersökningens slutsatser är att uppföljningar kan stötta interaktionen på målspråket och att det kan vara viktigt att läraren för det flerspråkiga klassrummet hittar ett innehåll som är intresseväckade för eleverna.
12

Product structure modeling for ETO system product considering the product lifecycle : A case study of ABB Mine Hoist

Zhang, Sumei January 2019 (has links)
In order to gain competitive advantages in markets, companies have provided a variety of customized products to satisfy customer-specific requirements, leading to not only a large amount of product data but also high cost, long lead-time and complexity of quality control. Efficient product data management throughout the product lifecycle has become increasingly crucial, of which product structure management is regarded as the most important constituent.  The study took ABB Mine Hoist system as a case to investigate how to construct a generic product structure model fit for engineer-to-order system offerings with the consideration of their sales-delivery product lifecycle. The aim of the model is to facilitate the product-related information sharing and reuse across a company, and the integration of different business operations throughout the entire product lifecycle as well. Based on the current situation analysis of product data management on ABB Mine Hoist, three major issues were identified which need to be addressed in the formulation of a generic structure model: namely the integration of requirements of multiple disciplines; the consistency of product information throughout the product lifecycle; and the constant update of product repository. Through illustrating the formulation of ABB Mine Hoist generic structure model, the method of how to construct a generic product structure model for engineer-to-order system product was presented. The model was achieved by applying the framework of the step-based product model and was regarded as a result of integrating domain-specific requirements. The adaptive generic product structure model was then employed to display the role of this generic model in the different phases of a sales-delivery lifecycle. The model could serve as a “master concept” to transfer common product information in the product lifecycle. It’s expected to benefit the business of engineer-to-order system product through improving the integration of different disciplines, enhancing information exchange and reuse. It could also provide an abstract and conceptual basis for potential product repository to reinforce data consistency and completeness.
13

一般帳戶投資型年金之資產負債管理:免疫理論與最適資產配置之應用

謝冠生 Unknown Date (has links)
本研究主要是針對投資型年金之資產負債管理作探討,其中是就規避利率風險對於資產負債管理上的影響以及分析資產配置最適化作為研究的架構,而所利用的研究方法乃是取決於建構利率隨機模型並輔以免疫理論與Markowitz投資組合理論,以期在規避利率風險的同時,亦能將資產配置達至最佳化。 首先,為實際模擬出符合現實經濟環境變動下的隨機利率期間模型,本研究利用C.I.R利率期間結構模型來建構年金保單期間的利率結構,並且由於投資型年金之保單價值的累積特性,因此本研究同時亦建構出連接保單價值的投資資產之報酬率型態,進而模擬出各期之現金流量以及各項投資資產的存續期間;再者,藉由Markowitz投資組合理論,以在免疫條件之限制下進行最適資產配置之評估。 最後,以某知名的保險公司所推出的投資型年金商品作為本研究之實證對象,透過模擬之方法,將研究模型中之各項參數予以評估,並且根據上述之研究過程將免疫理論與投資組合理論相連接,以檢視投資型年金商品在規避利率風險的狀態下,其最適之資產配置比例是否與現行法令之規範相牴觸,而能給予適時之建議。另外,由本實證結果可知,經由本研究的分析流程,可以有效地給予年金管理者規劃出年金資產負債管理時的最適投資組合比例,並且在增加外國投資資產時,更能有效的增加年金資產之報酬,同時也不影響保險法對於投資資產的比例與總金額之限制。再者,對於探討規避利率風險前後之資產組合之資產報酬之變化時,可以進一步了解到,當年金管理者在運用免疫策略來規避利率風險時,其所面對的風險成本之多寡,以作為制定避險決策時的依據。 / This research explores the asset-liability management (ALM) for the Investment-Link-Annuity. Two aspects investigated in this research are the interest rate risk and the optimal asset allocation. Moreover, the major issue investigated here is the trade-off between the optimal investment return and the hedge of interest rate risk. We refer this trade-off as ALM cost. By using stochastic interest rate model, Immunization theory and Portfolio Selection Model, we construct an ALM model to achieve the optimal asset allocation given on hedging the interest rate risk under the immunization strategies for the insurance company. First, we utilize the public trading data for investment market in Taiwan and in USA from 1985 to 2000 and the investment-link annuity product of a well-know insurance company in Taiwan to simulate the cash flow and demonstrate the implementation of our model. By analyzing different simulations under various scenarios, the empirical results are as the followings: 1.The ALM cost for immunization strategies is very small, and is estimated to be about 1% to 2%. Therefore, we suggest that insurance companies should start to undertake the asset liability management as soon as possible. 2.If relaxing the investment restrictions of Insurance Law or allowing insurance company to invest in foreign investment market, the overall investment return will be increased and the ALM cost will be reduced effectively.
14

Untersuchungen zur Struktur und Funktion taktiler kartographischer Medien und ihren Wechselwirkungen

Geiger, Stephanie 16 June 2008 (has links) (PDF)
Es wird heute weltweit versucht, Konzepte für vielfältige taktile kartographische Medien zu entwickeln, die vorrangig der allgemeinen Orientierung und Mobilität, aber auch verstärkt dem Wissenserwerb, z.B. im Geographieunterricht an Schulen für Blinde und Sehbehinderte, dienen sollen. Diese Konzepte müssen von denen der "visuellen Kartographie"1 zwangsläufig mehr oder weniger abweichen und auf weitgehend anderen Methoden, Regeln und Techniken beruhen. Wesentliche und durch die Praxis verifizierte Erkenntnisse der visuellen Kartographie sind der taktilen Kartographie zugänglich zu machen bzw. in/an diese zu adaptieren. Trotzdem dürfen grundlegende Theorien und Erfahrungen der Kartengestaltung und Kartennutzung für Sehende nicht völlig negiert werden.
15

An Introduction to Modern Pricing of Interest Rate Derivatives

Nohrouzian, Hossein January 2015 (has links)
This thesis studies interest rates (even negative), interest rate derivatives and term structure of interest rates. We review the different types of interest rates and go through the evaluation of a derivative using risk-neutral and forward-neutral methods. Moreover, the construction of interest rate models (term-structure models), pricing of bonds and interest rate derivatives, using both equilibrium and no-arbitrage approaches are discussed, compared and contrasted. Further, we look at the HJM framework and the LMM model to evaluate and simulate forward curves and find the forward rates as the discount factors. Finally, the new framework (after financial crisis in 2008), under the collateral agreement (CSA) has been taken into consideration.
16

Identifica??o e compara??o entre controle preditivo com modelo n?o linear e PI sintonizados com PSO em sistema de separa??o gravitacional de ?guia-?leo / Identification and comparison between predictive control with nonlinear model and PI control tuned using PSO in a gravitational separation system water-oil

Dantas, Andr? Felipe Oliveira de Azevedo 18 May 2012 (has links)
Made available in DSpace on 2015-03-03T15:07:34Z (GMT). No. of bitstreams: 1 AndreFOAD_DISSERT.pdf: 2002320 bytes, checksum: 0ebf2e7fb75a8ce59284dc72a43ef7ba (MD5) Previous issue date: 2012-05-18 / The separation methods are reduced applications as a result of the operational costs, the low output and the long time to separate the uids. But, these treatment methods are important because of the need for extraction of unwanted contaminants in the oil production. The water and the concentration of oil in water should be minimal (around 40 to 20 ppm) in order to take it to the sea. Because of the need of primary treatment, the objective of this project is to study and implement algorithms for identification of polynomial NARX (Nonlinear Auto-Regressive with Exogenous Input) models in closed loop, implement a structural identification, and compare strategies using PI control and updated on-line NARX predictive models on a combination of three-phase separator in series with three hydro cyclones batteries. The main goal of this project is to: obtain an optimized process of phase separation that will regulate the system, even in the presence of oil gushes; Show that it is possible to get optimized tunings for controllers analyzing the mesh as a whole, and evaluate and compare the strategies of PI and predictive control applied to the process. To accomplish these goals a simulator was used to represent the three phase separator and hydro cyclones. Algorithms were developed for system identification (NARX) using RLS(Recursive Least Square), along with methods for structure models detection. Predictive Control Algorithms were also implemented with NARX model updated on-line, and optimization algorithms using PSO (Particle Swarm Optimization). This project ends with a comparison of results obtained from the use of PI and predictive controllers (both with optimal state through the algorithm of cloud particles) in the simulated system. Thus, concluding that the performed optimizations make the system less sensitive to external perturbations and when optimized, the two controllers show similar results with the assessment of predictive control somewhat less sensitive to disturbances / Os m?todos de separa??o de ?leo e ?gua possuem, em sua maioria, aplica??es reduzidas devido ao custo operacional, a baixa efici?ncia de separa??o e ao alto tempo de processamento da separa??o. Por?m, Esses m?todos de tratamento s?o importantes devido a necessidade de extra??o dos contaminantes mais indesejados no processo de produ??o do petr?leo, a ?gua, e ao mesmo tempo, a concentra??o de ?leo na ?gua deve ser m?nima (da ordem de 40 a 20ppm) para o descarte regular da fase aquosa ao mar. A partir dessa necessidade de tratamento prim?rio objetiva-se, neste trabalho, estudar e implementar algoritmos de identifica??o para modelos polinomiais NARX em malha fechada, detectando a estrutura dos modelos, e comparar estrat?gias de controle PI e preditivo utilizando os modelos NARX (Nonlinear Auto-Regressive with Exogenous Input) atualizados online em uma combina??o de separador trif?sico em s?rie com tr?s baterias de hidrociclones. Os objetivos principais deste trabalho s?o obter um processo otimizado de separa??o trif?sica que regule o sistema, mesmo na presen?a de golfadas; mostrar que e poss?vel obter sintonias otimizadas para os controladores analisando a malha como um todo; e, avaliar e comparar as estrat?gias de controle PI e preditivo aplicadas ao processo. Para cumprir estes objetivos foi utilizado um simulador para representar o separador trif?sico e os hidrociclones, al?m de desenvolvidos algoritmos de identifica??o de sistemas (NARX) utilizando MQR (M?nimos Quadrados Recursivo), aliados a m?todos de detec??o de estrutura de modelos. Tamb?m foram implementados algoritmos de controle preditivo com modelos NARX atualizados online, e algoritmos de otimiza??o que utilizam PSO (Particle Swarm Optimization). O trabalho finaliza com a compara??o de resultados obtidos a partir da utiliza??o dos controladores PI e preditivo no sistema simulado ambos com par?metros otimizados atrav?s do algoritmo de nuvem de part?culas, e concluindo que as otimiza??es realizadas tornam o regulat?rio menos sens?vel a perturba??es externas (golfadas) e quando otimizados os dois controladores apresentam resultados similares, sendo os resultados do preditivo um pouco menos sens?vel as perturba??es
17

Controle adaptativo por modelo de referencia e estrutura vari?vel discreto no tempo

Jacome, Isael Calistrato 05 February 2013 (has links)
Made available in DSpace on 2015-03-03T15:07:35Z (GMT). No. of bitstreams: 1 IsaelCJ_DISSERT.pdf: 3710521 bytes, checksum: ffcd6197d140a1f366f43dd76204f72c (MD5) Previous issue date: 2013-02-05 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / With the technology progess, embedded systems using adaptive techniques are being used frequently. One of these techniques is the Variable Structure Model- Reference Adaptive Control (VS-MRAC). The implementation of this technique in embedded systems, requires consideration of a sampling period which if not taken into consideration, can adversely affect system performance and even takes the system to instability. This work proposes a stability analysis of a discrete-time VS-MRAC accomplished for SISO linear time-invariant plants with relative degree one. The aim is to analyse the in uence of the sampling period in the system performance and the relation of this period with the chattering and system instability / Com o avanco da tecnologia, sistemas embarcados utilizando t?cnicas adaptativas est?o sendo utilizados com mais frequencia. Uma dessas t?cnicas ? o Controlador adaptativo por Modelo de Referencia e Estrutura Variavel (VS-MRAC). A implementa??o dessa t?cnica em sistemas embarcados, requer a considera??o de um per?odo de amostragem que se n?o for levado em considera??o, pode afetar de maneira negativa a performance do sistema e at? mesmo lev?-lo a instabilizacao. Este trabalho prop?e uma an?lise de estabilidade do VS-MRAC para o caso discreto para uma planta SISO linear, invariante no tempo, de grau relativo unit?rio. O objetivo ? analisar a influ?ncia do per?odo de amostragem no desempenho do sistema, e a rela??o desse per?odo com o fen?meno de "chattering" e instabiliza??o do sistema
18

Pavilon moderního umění / Pavilion for Modern Arts

Hýblová, Kateřina January 2017 (has links)
The assignment of my degree work was a proposal of two variants of the steel structure of a modern art exhibition hall. The ground plan dimensions of the structure are 52,5 x 24 m. The whole structure of the two variants is supported by two quadrilateral truss columns and the upper floor level is at a height of 8 m above the ground. The ceiling structure is set by the truss girders. The proposal of two alternative solutions and the assessment of the main structure support elements forms another part of the work. With a winning option then a solution of the selected details, working out of the detailed drawings of the solved joints and the creation of the workshop documentation of the selected parts is supposed.
19

Hledání tvaru skořepinových konstrukcí / Form finding of shell structures

Musil, Jiří January 2017 (has links)
The theme of this doctoral thesis is the design of concrete shell structures with the focus on finding their optimal shape. The optimal shape of a concrete shell is the shape in which for a given load (usually the dead weight of the structure) no significant bending moments are generated in the shell and the structure is in the so-called membrane state. The inspiration for this thesis is the work of Swiss engineer Heinz Isler, who developed the shapes of shell structures using model tests of appropriately loaded flexible membranes. He developed the shell structure for large spans by inverting the resultant shape, which carried its weight almost entirely via membrane forces. The numerical solution of the above experiments using Midas Civil is presented herein. The basic principles of the method are demonstrated on the example of sagged cable. The numerically found shapes are compared with the analytical solution. A shell is designed based on the numerically found shapes and its stress response to dead load is described, particularly in relation to the membrane action. In the next part, the acquired knowledge and methods were used to design three relatively complicated shell structures. Each structure was statically analysed and its static behaviour was described. Structures with perfectly rigid or flexible supports, which simulate real behaviour of the supports, were studied. In the final phase, the results of static analysis of the selected shell were experimentally verified on a physical model in a scale of 1: 55.56. The model has been built using 3D printing. The thesis describes the use of a modelling similarity, the model design, the production process, and the experiment. The load test confirmed the optimal design of the shell structure and the validity of the numerical method for finding their shapes.
20

Půdorysně zakřivené konstrukce podepřené oblouky / Plan curved structures supported by arches

Trenz, Jan Unknown Date (has links)
The aim of this doctoral thesis is the research of the plan curved footbridges with the deck supported by arch. The research is preceded by the survey of present findings about arch structures with upper deck. The summary of reasons and difficulties of design of plan curved structures follows. The appropriate approach for design of plan curved structure is searched on the basis of methods for design of straight structure. The design of arch which is subjected to minimal bending moments is emphasised. At first, the structure is designed in the same way as straight structure and the limit plan curvature (for which the method is not suitable anymore) is sought. Then the approach based on method of inversion of suspended cable is examined and adapted for designing of plan curved arch geometry. The approach is thoroughly analysed through calculation model and experimentally verified on physical model in scale 1:10. The process of design, construction and testing of the physical model is described in detail. Measured deformations and stresses are compared with expected behaviour based on numerical analysis. The comparison proves good correlation between calculation and measurement, as well as high load bearing capacity of the structure.

Page generated in 0.078 seconds