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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.
1

Sediment dynamics on the inner continental shelf of the Basque country (N. Spain)

Uriarte, Adolfo January 1998 (has links)
No description available.
2

Essays in Growth and Development

January 2013 (has links)
abstract: This dissertation consists of three essays that broadly deal with the growth and development of economies across time and space. Chapter one is motivated by the fact that agricultural labor productivity is key for understanding aggregate cross-country income differences. One important proximate cause of low agricultural productivity is the low use of intermediate inputs, such as fertilizers, in developing countries. This paper argues that farmers in poor countries rationally choose to use fewer intermediate inputs because it limits their exposure to large uninsurable risks. I formalize the idea in a dynamic general equilibrium model with incomplete markets, subsistence requirements, and idiosyncratic productivity shocks. Quantitatively, the model accounts for two-thirds of the difference in intermediate input shares between the richest and poorest countries. This has important implications for cross-country productivity. Relative to an identical model with no productivity shocks, the addition of agricultural shocks amplifies per capita GDP differences between the richest and poorest countries by nearly eighty percent. Chapter two deals with the changes in college completion in the United States over time. In particular, this paper develop a dynamic lifecycle model to study the increases in college completion and average IQ of college students in cohorts born from 1900 to 1972. I discipline the model by constructing historical data on real college costs from printed government reports covering this time period. The main finding is that that increases in college completion of 1900 to 1950 birth cohorts are due primarily to changes in college costs, which generate a large endogenous increase in college enrollment. Additionally, evidence is found that supports cohorts born after 1950 underpredicted sharp increases in the college earnings premium they eventually received. Combined with increasing college costs during this time period, this generates a slowdown in college completion, consistent with empirical evidence for cohorts born after 1950. Lastly, the rise in average college student IQ cannot be accounted for without a decrease in the variance of ability signals. This is attributed the increased precision of ability signals primarily to the rise of standardized testing. Chapter three again deals with cross-country income differences. In particular, it is concerned with the fact that cross-country income differences are primarily accounted for by total factor productivity (TFP) differences. Motivated by cross-country empirical evidence, this paper investigates the importance individuals who operate their own firms because of a lack of other job opportunities (need-based entrepreneurs). I develop a dynamic general equilibrium labor search model with with entrepreneurship to rationalize this misallocation across occupations and assess its role for understanding cross-country income differences. Developing countries are assumed to have tighter collateral constraints on entrepreneurs and lower unemployment benefits. Because these need-based entrepreneurs actually have a comparative advantage as workers, they operate smaller and less productive firms, lowering aggregate TFP in developing countries. / Dissertation/Thesis / Ph.D. Economics 2013
3

Sustainable Food Production : Farmers’ management of their agroforestry  systems in Tanzania.

Hägglund, Johanna January 2015 (has links)
The future of food production contains some challenges. The production needs to increase in order to feed a growing population, but at the same time there is an increased need to transi- tion to more sustainable ways of cultivation. This can be a challenge since increased intensity and sustainability is not always compatible. Agroforestry systems have shown potential as sustainable food production system in previous research. The area where this study was con- ducted, Haraa in Babati District, has a long history of agroforestry. The aim of this study was to answer what resources agroforestry farmers used to manage their farms, to determine if the agroforestry systems could be regarded as sustainable. Circular economy was used as a theo- retical framework and resource flow as an analytical tool. This study investigated how the resource flow looked like on six agroforestry farms in a Haraa, a village in Tanzania. The empirical data was gathered with semi-structured interviews from 8 informants. The analysis showed that the farmers were dependent on few external resources and could produce or pre- form most of the needed resources inside their own system. The farms had a circular flow to a large extent, but some of the farms have room for improvement in the management regarding sustainability.
4

Some results on bilinear control systems with rank-one inputs

Chou, Yonggang January 1995 (has links)
No description available.
5

Loginės funkcijos termų generavimo algoritmas pagrįstas programinio prototipo modeliu / Terms’ of logical function generation algorithm based on software prototype model

Žemaitis, Tomas 16 August 2007 (has links)
Technologijų plėtojimas leidžia vis labiau vystytis sudėtingų elektroninių sistemų produkcijai. Visos šios sistemos turi būti patikrintos ir ištestuotos tam, kad užtikrinti tikslų jų funkcionavimą. Kai sistemų sudėtingumas didėja, testavimas tampa vienas iš svarbiausių faktorių nustatant galutinę produkto kainą. Žinomų žemo lygio metodų, skirtų techninės įrangos testavimui, nepakanka ir daugiau darbo turi būti atlikta abstrakčiame lygyje pradiniuose projektavimo etapuose negu klasikiniame ventiliniame ir registrų perdavimo lygiuose. Realizuotas algoritmas, kuris atsitiktinai generuoja įėjimo poveikį, pagal programinio prototipo modelį paskaičiuoja poveikio reakciją ir iškraipant po vien��� įėjimo poveikio signalo reikšmę apibrėžia galimus išėjimų loginių funkcijų termus. Nagrinėjant kitus įėjimo poveikius apibrėžti išėjimų loginių funkcijų termai patikslinami išmetant dalinius termus. Atsitiktinai sugeneravus ir išnagrinėjus daug įėjimo poveikių gaunami galutiniai išėjimų loginių funkcijų termai. Algoritmas negarantuoja , kad bus gauti visi ir tikslūs išėjimų loginių funkcijų termai, bet gauti termai gali būti naudojami testų generavimui. Gauti išėjimų loginių funkcijų termai užrašomi kartu su įėjimo poveikiu, pagal kurį termas buvo nustatytas, ir patys paskaičiuoti termai jau gali būti naudojami kaip tikrinantys testai. Gauti rezultatai galės būti panaudoti tolimesniems tyrimams: schemų testavimui, defektų šalinimui, funkcijos elementų palyginimui, algoritmo gerinimui... [toliau žr. visą tekstą] / The technological development is enabling production of increasingly complex electronic systems. All those systems must be verified and tested to guarantee correct behavior. As the complexity grows, testing is becoming one of the most significant factors that contribute to the final product cost. The established low-level methods for hardware testing are not any more sufficient and more work has to be done at abstraction levels higher than the classical gate and register-transfer levels. Realized algorithm, which random generates inputs, computes reaction based on software prototype model and deforming values of inputs one by one determines possible terms of logical functions. Analyzing other inputs determined terms of logical functions are corrected by eliminating partial terms. After random generating and analyzing a lot of inputs terminal terms of logical functions are derived. Algorithm doesn’t guarantee that all and exact terms of logical functions are obtained but those terms could be used when generating test vectors. Derived terms of logical functions’ outputs are recorded with input that formed them and following terms can be used as inspecting tests. Collected results can be used for further researches: schemes testing, defect detection, comparing elements of logical function, improving algorithm. Main aspects of design are introduced. Experimental accurateness of results and factors (initial number of random generated test vectors, improvement coefficient, maximum... [to full text]
6

Vehicle activity data for emissions modelling in urban areas of the Canadian Prairie Region

Patmore, Keenan Scott 12 January 2012 (has links)
This research develops and applies a methodology to calculate vehicle activity inputs for modelling of emissions from on-road vehicles using traffic count data. The thesis: (1) provides an understanding of emissions modelling in Canada and the U.S. and discusses the traffic activity data inputs required by vehicle emissions modelling software; (2) develops a methodology to collect and prepare vehicle activity data for an urban centre and applies this methodology by estimating vehicle activity for Winnipeg and Saskatoon; and (3) estimates vehicle emissions and then compares the sensitivity of estimating emissions using locally developed vehicle activity to estimating emissions using default vehicle activity. The methodology this research develops and applies to Winnipeg and Saskatoon is applicable to any jurisdiction in need of developing their own vehicle activity inputs for emissions modelling. The emissions estimates calculated using these different inputs emphasizes the importance of obtaining jurisdiction-specific input values for emissions modelling.
7

Vehicle activity data for emissions modelling in urban areas of the Canadian Prairie Region

Patmore, Keenan Scott 12 January 2012 (has links)
This research develops and applies a methodology to calculate vehicle activity inputs for modelling of emissions from on-road vehicles using traffic count data. The thesis: (1) provides an understanding of emissions modelling in Canada and the U.S. and discusses the traffic activity data inputs required by vehicle emissions modelling software; (2) develops a methodology to collect and prepare vehicle activity data for an urban centre and applies this methodology by estimating vehicle activity for Winnipeg and Saskatoon; and (3) estimates vehicle emissions and then compares the sensitivity of estimating emissions using locally developed vehicle activity to estimating emissions using default vehicle activity. The methodology this research develops and applies to Winnipeg and Saskatoon is applicable to any jurisdiction in need of developing their own vehicle activity inputs for emissions modelling. The emissions estimates calculated using these different inputs emphasizes the importance of obtaining jurisdiction-specific input values for emissions modelling.
8

Micro and small-scale generation in urban distribution networks

Acosta Alvarez, Jorge Luis January 2013 (has links)
As the world moves towards a more sustainable development, the energy coming from fossil fuels still produces the greenhouse gases that threaten the world’s climate. The UK government has established targets for the penetration of renewable energy generation and low-carbon alternatives for the electricity production. One of these technologies is microgeneration. In 2006, the UK government launched the Microgeneration Strategy pushing forward micro and small-scale generation as a supplementary source of energy for the country’s growing electricity demand. The proposal is focused on several technologies, including micro-wind and micro-PV, among others. These microgeneration technologies are now a reality and widespread across the distribution networks. Therefore, the analysis of the impact of these systems connected to distribution grids and the benefits of these technologies, alongside with their negative effects on the network is an important research area. Correct modelling of micro and small-scale renewablebased generation technologies implemented in urban areas, however, is not a simple task, as it requires an adequate representation of highly dispersed and uncontrolled generation systems. These systems are small in size, but high in numbers and usually experience large variations in available renewable energy inputs. This thesis presents aggregate models of urban micro and small-scale PV and wind generation systems, which are connected to low-voltage networks. The thesis analyses impact of urban PV and wind generation on the steady-state network performance (power flows and voltage profiles), taking into account variability of energy inputs. The presented analysis is of particular importance for the analysis of the future of power system supplies, which will have significantly higher penetration levels of renewable-based distributed generation technologies, resulting in a much wider range of interactions between microgeneration systems, loads and transmission/distribution networks. In order to perform this analysis, the resource assessment for urban areas has to be carried out to both quantify the potential for each technology and help in their modelling. This has been a challenge since the aggregation of microgeneration systems is far from simple, as the parameters, performance and size varies between different technologies. A solution presented in this thesis is an approach for simple yet accurate aggregation of microgeneration technologies. This approach allows to quantify and analyse their impact and effect on the power supply systems directly in terms of penetration levels and general technology characteristics.
9

Patterns of privilege : school inputs in Brazil / School inputs in Brazil

Usher, Kelly Ann 20 August 2012 (has links)
Brazil’s Bolsa Família and its impacts on student enrollment and achievement is studied increasingly frequently, but the quality of education received by Bolsa Família recipients is often not factored in. This study uses school data and the Bolsa Família registry to map patterns of school inputs for all Brazilian students, and to discover any patterns in inputs for specifically Bolsa Família recipient students. The availability of all types of school inputs follow similar regional patterns: low quantities of materials and low quality facilities in the North and Northeast regions, and the reverse in the South and Southeast, with the most consistently high averages of all inputs found in the Central-West. High proportions of these students tend to be present in the North and Northeast, affecting their access to school inputs. These students also tended to lack infrastructure and technology inputs, which likely have a mixed impact on student performance. / text
10

Essays on Efficiency Analysis

Asava-Vallobh, Norabajra 2009 May 1900 (has links)
This dissertation consists of four essays which investigate efficiency analysis, especially when non-discretionary inputs exist. A new approach of the multi-stage Data Envelopment Analysis (DEA) for non-discretionary inputs, statistical inference discussions, and applications are provided. In the first essay, I propose a multi-stage DEA model to address the non-discretionary input issue, and provide a simulation analysis that illustrates the implementation and potential advantages of the new approach relative to the leading existing multi-stage models of non-discretionary inputs, such as Ruggiero's 1998 model and Fried, Lovell, Schmidt, and Yaisawarng's 2002 model. Furthermore, the simulation results also suggest that the constant returns to scale assumption seems to be preferred when observations have similar sizes, but variable returns to scale may be more appropriate when their scales are different. In the second essay, I make comments on Simar and Wilson work of 2007. My simulation evidence shows that traditional statistical inference does not underperform the bootstrap process proposed by Simar and Wilson. Moreover, my results also show that the truncated model recommended by Simar and Wilson does not outperform the tobit model in terms of statistical inference. Therefore, the traditional method, t-test, and the tobit model should continue to be considered applicable tools for a multi-stage DEA model with non-discretionary inputs, despite contrary claims by Simar and Wilson. The third essay raises an example of applying my new approach to data from Texas school districts. The results suggest that a lagged variable (e.g. students' performance in the previous year), a variable which has been used in the literature, may not play an important role in determining efficiency scores. This implies that one may not need access to panel data on individual scores to study school efficiency. My final essay applies a standard DEA model and the Malmquist productivity index to commercial banks in Thailand in order to compare their efficiency and productivity before and after Thailand?s Financial Sector Master Plan (FSMP) that was implemented in 2004.

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