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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.
21

Extraction of Causal-Association Networks from Unstructured Text Data

Bojduj, Brett N 01 June 2009 (has links)
Causality is an expression of the interactions between variables in a system. Humans often explicitly express causal relations through natural language, so extracting these relations can provide insight into how a system functions. This thesis presents a system that uses a grammar parser to extract causes and effects from unstructured text through a simple, pre-defined grammar pattern. By filtering out non-causal sentences before the extraction process begins, the presented methodology is able to achieve a precision of 85.91% and a recall of 73.99%. The polarity of the extracted relations is then classified using a Fisher classifier. The result is a set of directed relations of causes and effects, with polarity as either increasing or decreasing. These relations can then be used to create networks of causes and effects. This “Causal-Association Network” (CAN) can be used to aid decision-making in complex domains such as economics or medicine, that rely upon dynamic interactions between many variables.
22

Analysis to China's Urban and Rural CPI Data

SUN, FEI January 2012 (has links)
No description available.
23

Energy Consumption and Growth : The case of Sweden for the industry and service sector

Petkova, Aleksandra, Jordeva, Melanija January 2012 (has links)
This paper examines the relationship between energy and economic growth in the case of Sweden.  It analyzes the role energy plays in the level of economic activity. The prevailing economic theories focus more on other factors as important for the economic growth. The included statistical data shows that the total energy use in Sweden has declined in the last couple of years. This is mainly as a result of the shift in energy use to higher quality fuels, electricity, optimized production process and machinery, and increased use of renewable energy sources. This paper investigates the connection between total energy use and levels of economic activity in Sweden. Furthermore, it discusses Sweden’s energy policy activities and their economic and environmental implications. Instead of looking at the entire economy, as some earlier papers, the focus is placed on the industrial and service sectors. This gives the possibility to better analyze the implemented energy policies, showing their effectiveness at these sectors. Time series analysis is employed following a four step procedure. First it is the Augmented Dickey-Fuller test performed, followed by the Johansen test and the Vector Error Correction Model (VECM). The results from VECM are interpreted with the help of the Wald test. The results from this four step procedure showed univariate cointegration between Industry`s output and energy consumption and bivariate cointegration between Service`s output and energy consumption. The paper further shows that there is a relation between the types of energy used in the economic sectors and the sectors` productivity levels. This paper also aims to demonstrate the environmental and economic effects from such relation.
24

Aid and Peace A Critique of Foreign Assistance, Conflict and Development

Kibriya, Shahriar 2011 December 1900 (has links)
In 2000, the World Bank estimated that 2.8 billion people lived on incomes of less than $2.00 a day. Meanwhile about forty percent of the world's population endured conflict, most of them from the same subset. The implementation of foreign assistance to mitigate poverty and conflict is a key focus of politicians, bureaucrats and social scientists. The goal of this research is to discover relationships among foreign aid, conflict, and socio-economic development, and assess the implications. Other evaluations either approach this issue from a hedonistic, theoretical standpoint, or follow a stylized project evaluation method. This research is intended to create a bridge between the two approaches by: 1) proposing theoretical models of assistance and conflict accounting for current status quo, and 2) introducing novel empirical methods to analyze the causes and effects of development, intervention and conflict. The research begins with a comparative analysis of different schools of thought concerning foreign intervention, conflict and development. Contemporary philosophies and policies provide the basis for assumptions and inquiries addressed in the latter part of this dissertation. The review is followed by a critique of relevant data and their sources. A theoretical model of foreign assistance allocation and its possible impacts on conflict is proposed. The theoretical model is verified through an empirical examination using inductive casual inference methods. It is concluded that under current mandates and policies, aggregate foreign assistance has no effect on conflict and development in poor countries. Research is then directed toward analyzing the effect of foreign assistance on conflict, disaggregated by sector. Agricultural and food security assistance were identified as the most effective method of mitigating conflict. The next segments of research concentrate on agricultural development. A model of agricultural development is proposed that will promote food security and mitigate conflict. In the last analysis, a direct causal relationship is found between commodity prices and conflict. Findings are summarized in the conclusion, and recommendations are provided for policy re-evaluations.
25

Causally Appropriate Graphical Modelling for Time Series with Applications to Economics, Ecology and Environmental Science

Meurk, Carla Siobhan January 2005 (has links)
I apply the GMTS approach to graphical modelling of time series to data sets from economics, ecology and environmental science. This approach improves on traditional approaches to modelling insofar as it selects the most parsimonius model. I improve on this approach by removing some redundancies in the GMTS approach. However, a bias in terms of which links are selected means that it is unlikely that this model will select the best causal model.
26

Estimating causal effects with observational data : the intensity-score approach to adjusting for confounding /

Redman, Mary W. January 2004 (has links)
Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (p. 123-129).
27

Visual Analytics Methodologies on Causality Analysis

January 2019 (has links)
abstract: Causality analysis is the process of identifying cause-effect relationships among variables. This process is challenging because causal relationships cannot be tested solely based on statistical indicators as additional information is always needed to reduce the ambiguity caused by factors beyond those covered by the statistical test. Traditionally, controlled experiments are carried out to identify causal relationships, but recently there is a growing interest in causality analysis with observational data due to the increasing availability of data and tools. This type of analysis will often involve automatic algorithms that extract causal relations from large amounts of data and rely on expert judgment to scrutinize and verify the relations. Over-reliance on these automatic algorithms is dangerous because models trained on observational data are susceptible to bias that can be difficult to spot even with expert oversight. Visualization has proven to be effective at bridging the gap between human experts and statistical models by enabling an interactive exploration and manipulation of the data and models. This thesis develops a visual analytics framework to support the interaction between human experts and automatic models in causality analysis. Three case studies were conducted to demonstrate the application of the visual analytics framework in which feature engineering, insight generation, correlation analysis, and causality inspections were showcased. / Dissertation/Thesis / Doctoral Dissertation Computer Science 2019
28

Dual causality and Bell's essential conflict

Scott, Thomas Petrie January 2014 (has links)
The Bible claims that God actively governs the world on a day-to-day basis; that is, he is an active causal agent. The Bible also appears to claim that there are naturally occurring events; that is, in addition to divine causality there is natural causality. The thesis explores whether dual causality is theologically viable; whether nature may allow space for God to govern without violation of the laws of nature; and the desirability of causal closure. Having arrived at the conclusion that dual causality is viable both theologically and physically, and that causal closure is desirable, it will be proposed that dual causality is a feature of the world. Arguably the most notable dispute in twentieth century physics was that between Niels Bohr and Albert Einstein, culminating in the EPR thought experiment. The EPR paradox was refined and clarified by John Bell into an 'essential conflict' between special relativity and any interpretation of quantum mechanics. As a test case dual causality will be applied to Bell's essential conflict. The thesis claims that dual causality resolves Bell's essential conflict and also provides the most complete explanation of the world as revealed by modern physics. It will suggest that a theological interpretation of quantum mechanics may be possible.
29

Children's understanding the inside of the body, illness and death

Deluca, Paolo January 2000 (has links)
No description available.
30

Causality, Prediction, and Replicability in Applied Statistics: Advanced Models and Practices

Pütz, Peter 03 May 2019 (has links)
No description available.

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