• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 212
  • 90
  • 38
  • 16
  • 15
  • 13
  • 8
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • Tagged with
  • 489
  • 489
  • 174
  • 115
  • 98
  • 75
  • 75
  • 53
  • 53
  • 47
  • 45
  • 43
  • 38
  • 35
  • 34
  • 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.
291

Geometria do desacoplamento e integração numérica de equações diferenciais não lineares implícitas. / Decoupling geometry and numerical integration of differential equations implicit nonlinear systems.

Iderval Silva de Souza 24 November 2006 (has links)
Existem métodos de integração de equações algébrico diferenciais não lineares (DAEs) considerados clássicos pela literatura. Porém, neste trabalho, através uma abordagem geométrica, apresenta-se um método de integração de DAEs. Tal método é inspirado na teoria de desacoplamento de sistemas não lineares explícitos, quando se considera que as saídas são restrições algébricas. Neste caso, a DAE pode ser identificada como dinâmica zero. O resultado principal desta abordagem é que, dada uma DAE, sob certas condições, é possível a construção de um sistema explícito, de tal maneira, que as soluções desse sistema explícito convergem para as soluções da DAE. / Classical methods for numerical integration of diferential algebraic equations (DAEs) can be formal in the literature. In this work, using a diferential geometric approach, a numerical method of integration of DAEs is established. This method is inspired in the decoupling theory of nonlinear explicit systems, when one considers that the outputs are algebraic constraints. The main result is the construction of an explicit system, whose solutions converge to the solutions of the DAE.
292

Cross-Border Effects of Fiscal Policies / Přeshraniční dopady fiskálních politik

Maleček, Petr January 2015 (has links)
This study seeks to analyse and quantify cross-border effects of discretionary fiscal policies from two major points of view. The aggregate approach rests on the use of the structural vector autoregression model (SVAR) and its extension, the global vector autoregression model (GVAR). The discretionary fiscal impulse itself is then defined as a change in cyclically adjusted balance of the government sector, calculated at quarterly frequencies. This section is then complemented by a case study of a single measure: the German car scrapping scheme during 2009 and its effects on the Czech economy. It was found that cross-border effects of discretionary fiscal policies may be indeed present, in case certain conditions are met. Importantly, a fiscal impulse has to originate from a sufficiently large economy and there needs to be a tight trade linkage between examined countries. In most cases, cross-border effects have also been found of lesser magnitude than direct impacts of fiscal policies on the domestic country. Finally, as demonstrated on the German-Czech case, even a single fiscal measure can trigger substantial cross-border spillovers. It was estimated that this measure positively contributed to real GDP growth in 2009 in the Czech Republic by 0.44 pp.
293

Assessment of the Effects of Sanctions on trade between the EU and Russia / Ohodnotenie vplyvu sankcií na obchod medzi EU a Ruskom

Hašková, Barbara January 2015 (has links)
This thesis concerns about the effectiveness of sanctions imposed between Russia and the EU in 2014. Firstly are conducted theoretical foundations of sanctions and their imposition from the EU as well as Russian contra-sanctions. Secondly, the analysis is based on the gravity model in trade in log-linear form and further develop out-of-sample estimations about trade potentials. Although trade potentials did not proved the expected decrease in exports from EU to Russia, the Input-Output analysis of impacts on exports of food products did so. Results yielded calculated impacts on GDP of various countries due to food embargo that are more or less comparable with the actual evolution of GDP and trade flows. Thirdly, the indirect effects of sanctions of third country effect and re-exports are observed from trade patterns. There has been recorded increased exports of food related products from the EU towards members of Euroasian Customs Union as well as increased imports from these countries to Russia. Finally, the results points out decreased economic activity of Russia due to depreciation of domestic currency, capital flight, decline in oil prices and also sanctions adding up to the problems the economy deals with. The economic impacts of sanctions are present in both parties. However, from the political view sanctions did not proved to be effective so far. Russian intervention in Ukraine territory is continuing.
294

Utbyte av styrsystem : Projektering, implementering och verifiering / Exchange of PLC control systems : Projection, implementation and authentication

Johansson, Anton, Bigeat, Régis, Kerr, Michael January 2020 (has links)
Sjöfartshögskolan i Kalmar behövde förnya sin programvara för programmerbara styrsystem (PLC), detta ledde till att två styrsystem blev påverkade. Det ena är för att styra och reglera en ångprocess medan den andra används för att styra en simulatortank. Det har tidigare varit relativt svårt för lärare att få studenter att komma igång med programmeringen då det förra systemet var komplext. Linnéuniversitet bestämde sig därför att ett utbyte av styrsystemet för ångprocessen och arbetsstationer var att föredra. Ett viktigt mål var att få arbetsstationerna mindre eftersom antalet stationer kommer utökas. Det framkom under arbetets gång att uppdatering av dokumentation av systemen behövde göras samt en förenkling av växling mellan PLC och regulator. Resultatet är ett system som är kompakt och lättare att hantera. / Kalmar Maritime Academy needed to renew the software for programmable logic controller (PLC). There are two systems that are involved, one is for controlling a steam process and the other a simulation of a cistern. Previously it has been relatively difficult for the teachers to get the students to begin with the programming because the prior system was to complex. Linnaeus University therefore decided that a change of control system for the steam system and workstation was preferable. An important task was to minimize the workstation size because the number of stations are increasing. While performing the work it became apparent that the documentation for the system needed to be updated, and to simplify the switch between PLC and regulator control. The result was a compact and easier system to use.
295

Just-in-time (JIT) concept: a case study of its implementation in a computer peripheral manufacturer in HongKong

Chaw, Chi-chuen., 周志聰. January 1991 (has links)
published_or_final_version / Business Administration / Master / Master of Business Administration
296

Investigating cognitive control in language switching

Clapp, Amanda Louise January 2013 (has links)
How do bi/multilinguals switch between languages so effectively that there is no obvious intrusion from the alternatives? One can examine this by comparing language selection with task selection, or language switching with task switching. This is the approach adopted in the first of two strands of research presented in this thesis. In task switching, providing advance warning of the task typically leads to a reduction in the performance ‘switch cost’, suggesting top-down biasing of task selection. It is not clear whether the language switch cost also reduces with preparation, partly because there have been very few attempts to examine preparation for a language switch, and partly because these attempts suffered from non-trivial methodological drawbacks. In Experiments 1-3 I used an optimised picture naming paradigm in which language changed unpredictably and was specified by a language cue presented at different intervals before the picture. Experiment 1, conducted on ‘unbalanced’ bilinguals, revealed some evidence of reduction in the language switch cost for naming times with preparation, but only when cue duration was short. In an attempt to further optimise the paradigm, in Experiment 2 the cue-stimulus interval (which was varied from trial to trial in Experiment 1), was varied over blocks instead. Visual cues were replaced with auditory cues – the latter also enabled a comparison between semantically transparent word cues (the spoken names of the languages) and less transparent cues (fragments of national anthems). Experiment 2 revealed a reduction in switch cost with preparation for naming latencies, but only in the second language; the first language showed the reverse. To examine whether the increase in switch cost with preparation in the first language could be due to unbalanced bilinguals biasing processing towards L2, balanced bilinguals were tested in Experiment 3. This revealed a robust reduction in switch cost in naming latencies for both languages, which was driven primarily by the trials with the anthem cues. However, in the error rates the switch cost increased with preparation interval, thus complicating the interpretation of the reduction observed for response times. Experiment 4 investigated whether preparation for a language switch elicits the electrophysiological patterns commonly found during preparation for a task switch – a switch-induced positive polarity Event-Related Potential (ERP) with a posterior scalp distribution. Contrary to a recent report of the absence of the posterior positivity in language switching, it was clearly present in the present EEG data. As in task switching, the amplitude of the posterior positivity predicted performance. The electrophysiological data suggest that preparation for a language switch and preparation for a task switch rely on highly overlapping control mechanisms. The behavioural data suggest that advance control can be effective in language switching, but perhaps not as effective as in task switching. Experiments 1-3 also examined the effect of stimulus associative history – whether the language used on the previous encounter with a given stimulus influenced performance on the current trial). Having previously named a given picture in the same language benefited overall performance, but did not do so more for switches than repeats. Thus, stimulus associative history does not seem to contribute to the language switch cost. The second strand of my research asked whether bilinguals can set themselves independently for speech vs. comprehension. Previous research has examined the cost of switching the language in output tasks and in input tasks. But, it is not clear whether one can apply separate control settings for input and output selection. To investigate this, I used a paradigm that combined switching languages for speech production and comprehension. My reasoning was that, if there is cross-talk between the control settings for input vs. output, performance in one pathway should benefit if the language selected for the other pathway is the same relative to when it is different: a ‘language match effect’. Conversely, if there is no cross-talk, there should not be a language match effect. In Experiment 5 bilinguals alternated predictably between naming numbers in their first and second language (in runs of 3 trials), whilst also having to semantically categorise spoken words which occasionally (and unpredictably) replaced the numbers. The language of the categorisation ‘probes’ varied over blocks of ~17 naming runs, but was constant within a block. The results showed a clear match effect in the input task (categorisation), but not the output task (naming). To examine the potential role of proficiency, Experiment 6 used the same paradigm to test unbalanced and balanced bilinguals. The pattern of results was qualitatively similar in both groups to that observed in Experiment 5: a language match effect confined to the input task. These results suggest ‘leakage’ from the output control settings into the input control settings.
297

Input-Output Analysis of Emissions Embodied in Swedish Imports from China, 1995-2009

Pär, Holmberg January 2017 (has links)
With the growth of international trade many researchers are questioning the effects on the environment by emissions embodied in international trade flows. The embodied emissions in the import (EEI) and export of Sweden are relatively unexplored despite being a trade-dependent country. However, a few earlier studies indicate that the largest share of embodied CO2 in the international trade of Sweden is in the import from China. This thesis evaluates Sweden’s EEI from China during the years 1995-2009 by using an input-output analysis with the emissions in bilateral trade approach. Different from existing studies, the sector distributions of the EEI are outlined with high transparency and the driving factors for the change in EEI are identified by using a structural decomposition analysis (SDA). Results shows that the EEI increased significantly from 1995-2009 and that the main increase occurred during 2002-2007. The import of electrical and optical equipment, textile products and renting of machinery and equipment contributed to the largest share of the EEI. The EEI induced from the total import were mainly generated from electricity, gas and water supply and other heavy industries. Results from the SDA showed that the scale effect from increased imports from especially heavy industries had a large influence on the growth in embodied CO2 emissions. The service sectors contributed to the second largest share of the increase in the EEI due to scale and structural effects. The technical effect, on the contrary, was markedly offsetting the increase of embodied CO2 emissions both for heavy and light industries.
298

A Design Approach for Digital Computer Peripheral Controllers, Case Study Design and Construction

Cabrera, A. L. 05 1900 (has links)
The purpose of this project was to describe a novel design approach for a digital computer peripheral controller, then design and construct a case study controller. This document consists of three chapters and an appendix. Chapter II presents the design approach chosen; a variation to a design presented by Charles R. Richards in an article published in Electronics magazine. Richards' approach consists of a finite state machine circuitry controlling all the functions of a controller. The variation to Richards' approach consists of considering the various logically independent processes which a controller carries out and assigning control of each process to a separate finite state machine. The appendix contains the documentation of the design and construction of the controller.
299

Structural production layer decomposition: a new method to measure differences between MRIO databases for footprint assessments

Wieland, Hanspeter, Giljum, Stefan, Bruckner, Martin January 2018 (has links) (PDF)
Recent empirical assessments revealed that footprint indicators calculated with various multi-regional input-output (MRIO) databases deliver deviating results. In this paper, we propose a new method, called structural production layer decomposition (SPLD), which complements existing structural decomposition approaches. SPLD enables differentiating between effects stemming from specific parts in the technology matrix, e.g. trade blocks vs. domestic blocks, while still allowing to link the various effects to the total region footprint. Using the carbon footprint of the EU-28 in 2011 as an example, we analyse the differences between EXIOBASE, Eora, GTAP and WIOD. Identical environmental data are used across all MRIO databases. In all model comparisons, variations in domestic blocks have a more significant impact on the carbon footprint than variations in trade blocks. The results provide a wealth of information for MRIO developers and are relevant for policy makers designing climate policy measures targeted to specific stages along product supply chain.
300

Análise dinâmica estrutural de uma cadeia global de geração de valor modelada por hipergrafos: estudo de caso da cadeia global do ferro e aço de 1996 até 2016 / Dynamic structural analysis of a global value chain modelled by hypergraphs: a case study of the global iron and steel chain from 1996 to 2016

Andrade Junior, José Augusto Morais de 15 March 2019 (has links)
Embora o Brasil tenha uma das maiores reservas de minério de ferro do mundo, estimada em 170 bilhões de toneladas, e também possua siderúrgicas próximas às minas de ferro, como a Usiminas, por exemplo, o Brasil exporta minério de ferro e importa produtos semi-acabados de aço de outros países, como o Japão e a China. O objetivo desta pesquisa é modelar a cadeia de valor global de ferro e aço e analisar sua dinâmica estrutural para verificar se esse modelo é capaz de determinar os fatores que impulsionam a geração de valor e que levaram alguns países a ter maior impacto sobre seu desenvolvimento econômico do que outros. A modelagem da cadeia de valor usa a técnica padrão de análise de entrada-saída de balanço de massa (método de modelagem estrutural ampliado de Leontief), detalhado na revisão da literatura. Para obter esses resultados, foi necessário coletar e consolidar diferentes bancos de dados utilizando ferramentas capazes de conciliar, tratar e analisar o grande volume de dados presentes nesses diferentes bancos de dados, em diferentes unidades e níveis de agregação. A análise da dinâmica estrutural revelou uma série de aspectos fundamentais para entender a guerra comercial entre os EUA e a China. A China passou de 10% da produção mundial de aço bruto para 50% em 20 anos, reduzindo a relevância de outros países no contexto da cadeia de ferro e aço. Além disso, a análise revelou que o Brasil exporta quase exclusivamente minério de ferro bruto. A Austrália, por exemplo, conseguiu agregar mais valor do que o Brasil. Isso revela, portanto, que a análise da dinâmica estrutural modelada por hipergrafos pode gerar informações semânticas relevantes sobre o contexto, atores e interesses envolvidos e pode servir como um mapa para orientar decisões e políticas voltadas para uma melhor inserção e atuação de um país em uma cadeia global de produção / Although Brazil has one of the largest reserves of iron ore in the world, estimated at 170 billion tons, and also steel mills near the iron mines, such as Usiminas, e.g., Brazil exports iron ore and imports (semi-)finished steel products from other countries, such as Japan and China. The objective of this research is to model the global value chain of iron and steel and to analyse its structural dynamics to verify if this model is able to determine the factors that drive the generation of value and that have led some countries to have greater impact on their economic development than others. Value chain modelling uses the standard mass balance input-output analysis technique (Leontief\'s extended structural modelling method), detailed in the literature review. To obtain these results, it was necessary to collect and consolidate different databases using tools able to reconcile, treat and analyse the large volume of data present in these different databases, in different units and levels of aggregation. The analysis of the structural dynamics revealed a series of fundamental aspects to understand the commercial war between the USA and China. China has shifted from 10% of the world\'s crude steel production to 50% in 20 years, reducing the relevance of other countries in the context of the iron and steel chain. In addition, the analysis revealed that Brazil exports almost exclusively crude iron ore. Australia, for example, was able to add more value than Brazil. This reveals, therefore, that the analysis of the structural dynamics modelled by hyper-graphs can generate relevant semantic information about the context, actors and interests involved and can serve as a map to guide decisions and policies aimed at a better insertion and performance of a country in a global value chain

Page generated in 0.0529 seconds