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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.
611

Regional Economic Studies on Natural Resources and Their Economic Impact

Bae, Jinwon, Bae, Jinwon January 2017 (has links)
Various adaptation and mitigation strategies have been explored to cope with changes in the climate. Estimating these strategies impacts on the local economy is one of the growing and pressing issues for the management of natural resources. This thesis consists of three parts and aims to contribute to regional economic studies by analyzing: (1) the economic impact of solar energy facilities, (2) the level of virtual water flow and the effectiveness of scenarios to mitigate water resource shortage, and (3) the impact of climate change on agriculture through a Ricardian approach weighted by stream flow connectivity. As an increasingly adopted renewable energy resource, solar power has a high potential for carbon emission reduction and economic development. In the first essay the impacts on jobs, income, and economic output of a new solar power plant are calculated in an input-output framework. The contribution is twofold. First, we compare the multipliers generated by the construction and operation/maintenance of a plant located in California with those that would pertain had it been built in Arizona. Second, we point out the differences in the results obtained with the popular IMPLAN software from those obtained with the solar photovoltaic model of JEDI. The second essay focuses on water use in Arizona. As much as 73% of the state's scarce water is used by a single sector: crop production. Because 79% of Arizona's crop production is consumed outside the state, this means that, 67% of the water available in the state is being exported to the rest of the country and abroad. This should be of major concern for a state expected to see its population grow and its climate get drier. Using input-output techniques we explore three scenarios aimed at saving 19% of the water available. This figure is based on the results of the first of the scenarios that explores how much can be saved through improving the efficiency of the current irrigation system. The second scenario shows that equivalent water savings could be reached by a twenty-seven-fold increase in the price of water. The third scenario shows that a 19.5% reduction in crop exports could conserve an equal amount of water. The model results suggest that the least costly solution is a more efficient irrigation system, while export reduction is the second best choice. The third and final essay offers an extension of the well-known Ricardian model of agrarian economic rent. In spite of its popularity among studies of the impact of climate change on agriculture, there has been few attempts to examine the role of interregional spillovers in this framework. We remedy this gap by focusing on the spatial externalities of surface water flow used for irrigation purposes and demonstrate that farmland value—the usual dependent variable used in the Ricardian framework—is a function of the climate variables experienced locally and in upstream locations. This novel approach is tested empirically on a spatial panel model estimated across the counties of the Southwest USA for every five-year period from 1997 to 2012. This region is one of the driest in the country, hence its agriculture relies heavily on irrigation with the preponderance of the sources being surface water transported over long distances. The results highlight the significant role of irrigation spillovers and indicate that the actual impact of climate change on agriculture and subsequent adaptation policies can no longer overlook the streamflow network.
612

On the energy efficiency of spatial modulation concepts

Stavridis, Athanasios January 2015 (has links)
Spatial Modulation (SM) is a Multiple-Input Multiple-Output (MIMO) transmission technique which realizes low complexity implementations in wireless communication systems. Due the transmission principle of SM, only one Radio Frequency (RF) chain is required in the transmitter. Therefore, the complexity of the transmitter is lower compared to the complexity of traditional MIMO schemes, such as Spatial MultipleXing (SMX). In addition, because of the single RF chain configuration of SM, only one Power Amplifier (PA) is required in the transmitter. Hence, SM has the potential to exhibit significant Energy Efficiency (EE) benefits. At the receiver side, due to the SM transmission mechanism, detection is conducted using a low complexity (single stream) Maximum Likelihood (ML) detector. However, despite the use of a single stream detector, SM achieves a multiplexing gain. A point-to-point closed-loop variant of SM is receive space modulation. In receive space modulation, the concept of SMis extended at the receiver side, using linear precoding with Channel State Information at the Transmitter (CSIT). Even though receive space modulation does not preserve the single RF chain configuration of SM, due to the deployed linear precoding, it can be efficiently incorporated in a Space Division Multiple Access (SDMA) or in a Virtual Multiple-Input Multiple-Output (VMIMO) architecture. Inspired by the potentials of SM, the objectives of this thesis are the evaluation of the EE of SM and its extension in different forms of MIMO communication. In particular, a realistic power model for the power consumption of a Base Station (BS) is deployed in order to assess the EE of SM in terms of Mbps/J. By taking into account the whole power supply of a BS and considering a Time Division Multiple Access (TDMA) multiple access scheme, it is shown that SM is significantly more energy efficient compared to the traditional MIMO techniques. In the considered system setup, it is shown that SM is up to 67% more energy efficient compared to the benchmark systems. In addition, the concept of space modulation is researched at the receiver side. Specifically, based on the union bound technique, a framework for the evaluation of the Average Bit Error Probability (ABEP), diversity order, and coding gain of receive space modulation is developed. Because receive space modulation deploys linear precoding with CSIT, two new precoding methods which utilize imperfect CSIT are proposed. Furthermore, in this thesis, receive space modulation is incorporated in the broadcast channel. The derivation of the theoretical ABEP, diversity order, and coding gain of the new broadcast scheme is provided. It is concluded that receive space modulation is able to outperform the corresponding traditional MIMO scheme. Finally, SM, receive space modulation, and relaying are combined in order to form a novel virtual MIMO architecture. It is shown that the new architecture practically eliminates or reduces the problem of the inefficient relaying of the uncoordinated virtual MIMO space modulation architectures. This is undertaken by using precoding in a novel fashion. The evaluation of the new architecture is conducted using simulation and theoretical results.
613

Identifying and analysing carbon 'hot-spots' in an Inter-Regional Input Output framework

Katris, Antonios January 2015 (has links)
Input Output frameworks have been widely used to study the emissions of industrial sectors either in specific economies or globally but usually focus on aggregated measures under production or consumption accounting principles (PAP and CAP). This leads to a lack of transparency in terms of the structure of the emissions and provides limited information on what are the main drivers of the emissions allocated to each sector under PAP and CAP. This information gap limits the options of policy makers to interventions on whole sectors, rather than the components of their supply chains that hold the major shares of the total embodied emissions. In this thesis we argue in favour of a more disaggregated, a ‘hot-spot’, approach that provides a better understanding of the structure of emissions under both of these headline measures. We develop a methodology to identify CO2 ‘hot-spots’ in downstream and upstream supply chains, both domestic and global. The methodology is applied first to a Single Region Input Output framework for China in 2005 identifying ‘Electricity, Gas and Water Supply’ as the Chinese sector with the highest direct emissions. Examination of the sector’s domestic downstream supply chain reveals that the majority of emissions are generated to support the final demand of other domestic sectors. Of these ‘Construction’ is the main driver and it also is the Chinese sector that is found to have the largest domestic CO2 footprint, with several emissions ‘hot-spots’ in its domestic upstream supply chain. The ‘hot-spot’ methodology is then extended to a global Inter-Regional Input Output framework to consider ‘hot-spots’ in a global supply chain context. By focusing on 2009 (the year for which appropriate data are most recently available) and UK total final demand we find that Chinese ‘Electricity, Gas and Water Supply’ is the non-UK sector with the largest direct emissions driven by UK total final demand. Studying this sector’s downstream supply chain outside China reveals that a large share of the sector’s emissions is ultimately generated to support several UK-based sectors’ domestic final demand. Furthermore, the UK ‘Health and Social Work’ sector is identified as the UK sector with the second largest global footprint to support domestic final demand. We identified a number of ‘hot-spots’ in the international part of its upstream supply chain, with a key finding being its dependence on the activity and the embodied emissions in global chemicals production. Finally, the thesis goes on to demonstrate how conducting ‘hot-spot’ analysis on disaggregated regional/sub-national Input Output tables can provide more detailed local level analysis of ‘hot-spot’ findings from the Inter-Regional Input Output framework. The key finding in this respect is the importance of introducing region specific emissions data where possible, as non-region specific data can lead in incorrect estimation of the embodied emissions in any component of the supply chains of any sectors. In general, through this research project we developed a methodology that can enhance the policy makers understanding of the structure and the drivers of the emissions generated throughout the economy. This additional information on the emissions structure, when combined with familiar IO analysis on employment and value-added for example, has the potential to lead to more targeted/focused policies, which result in significant emissions reduction with the minimum employment, resources and value-added cost.
614

Turbo Receiver for Spread Spectrum Systems Employing Parity Bit Selected Spreading Sequences

Mirzaee, Alireza January 2012 (has links)
In spread spectrum systems employing parity bit selected spreading sequences, parity bits generated from a linear block encoder are used to select a spreading code from a set of mutually orthogonal spreading sequences. In this thesis, turbo receivers for SS-PB systems are proposed and investigated. In the transmitter, data bits are rst convolutionally encoded before being fed into SS-PB modulator. In fact, the parity bit spreading code selection technique acts as an inner encoder in this system without allocating any transmit energy to the additional redundancy provided by this technique. The receiver implements a turbo processing by iteratively exchanging the soft information on coded bits between a SISO detector and a SISO decoder. In this system, detection is performed by incorporating the extrinsic information provided by the decoder in the last iteration into the received signal to calculate the likelihood of each detected bit in terms of LLR which is used as the input for a SISO decoder. In addition, SISO detectors are proposed for MC-CDMA and MIMO-CDMA systems that employ parity bit selected and permutation spreading. In the case of multiuser scenario, a turbo SISO multiuser detector is introduced for SS-PB systems for both synchronous and asynchronous channels. In such systems, MAI is estimated from the extrinsic information provided by the SISO channel decoder in the previous iteration. SISO multiuser detectors are also proposed for the case of multiple users in MC-CDMA and MIMO-CDMA systems when parity bit selected and permutation spreading are used. Simulations performed for all the proposed turbo receivers show a signi cant reduction in BER in AWGN and fading channels over multiple iterations.
615

Thermo-Optic and Refractometric Performance of Long-Range Surface Plasmon Multiple-Output Mach-Zehnder Interferometers

Fan, Hui January 2016 (has links)
Long-range surface plasmon-polaritons are transverse-magnetic polarized optical surface waves formed through the interaction of photons with free electrons at the surface of metal slabs or stripes. They play important roles in a variety of field such as integrated optics, amplifiers and lasers, optical sensing, modulation, etc. Due to their longer propagation length and deeper penetration depth compared to those of single-interface surface plasmon-polaritons, they have become increasingly promising in optical sensing. In sensing applications, it is necessary to reduce the noise level in order to obtain a lower detection limit. One way to achieve this is to use dual- or triple-output Mach-Zehnder interferometers so that the common perturbations among the outputs can be suppressed. The objective of this thesis is to provide deeper insights on the performances of dual- and triple-output Mach-Zehnder interferometers in thermo-optic and optical bulk sensing applications, theoretically and experimentally, and to demonstrate their ability to suppress common perturbations and lower the detection limit. On the theoretical side, the objective is approached by constructing a model for the transfer characteristic. For dual-output Mach-Zehnder interferometers, the plane-wave model is used to develop a general model for thermo-optic sensing and an unbalanced model for optical bulk sensing. For triple-output ones, local normal mode theory is used with modal analysis for the 3×3 coupler portion of the structure. Quantitative methods to analyze and compare different detection schemes are developed. The minimum detectable phase shift is determined for the case of thermo-optic sensing while the detection limit is determined for optical bulk sensing. On the experimental side, the objective is approached by providing a direct experimental demonstration of the transfer characteristics at an optimized operating wavelength for the coupler portion of the device, then comparing to theory. Time traces are carried out and various detection schemes are applied to suppress common perturbations among the outputs, and to improve the minimum detectable phase shift or the detection limit.
616

River Analysis and Climate Change: Continuous Prediction of Clay-Bed Erosion in Watts Creek

Brennan, Colin January 2017 (has links)
Predicted future precipitation is downscaled and used to drive a hydrologic model to assess future erosion potential in a semi-alluvial clay-bed watercourse, Watts Creek. The 21 km2 watershed is predominantly urban, with overall impervious cover of 22%, and the remaining land use split between agricultural and forested areas. Continuous simulations for the open water year, excluding spring freshet (April 1st to October 31st) were performed using the SWMHYMO (Stormwater Management Hydrologic Model) lumped hydrologic modelling platform. A shear stress exceedance and stream power erosion routine was added to the platform to calculate erosion potential. To account for uncertainty in the collected data, nine different observed discharge data sets were used to calibrate the model, each leading to a distinct set of calibrated parameter values. The difference between the observed data sets lies in the choice of rating curves and the collection period. The 2041-2080 precipitation outputs of the fourth version of the Canadian Regional Climate Model (CanRCM4) ran under Representative Concentration Pathways (RCPs) 4.5 and 8.5 at the MacDonald Cartier International Airport were downscaled using quantile matching and then used as input to the hydrologic model. For each set of calibrated parameters, a cumulative effective work index (CWI) based on the reach-averaged shear stress was calculated for Watts Creek during the open water year using both the historic (1968 2007) and projected future (2041-2080) flows, using a bed material critical shear stress for entrainment of 3.7 Pa. Results suggest an increase of 75% (resp. 139%) under RCP4.5 (resp. RCP8.5) in CWI compared to historic conditions for the average measured bed strength. The work index increase is driven by an increased occurrence of above-threshold events, and more importantly by the increased frequency of large events. The predicted flow regime under climate change would significantly alter the erosion potential and stability of Watts Creek. A channel adjustment sensitivity analysis, which balances future erosion potential with historic potential, was implemented and indicated that the channel could widen in the future from the current bankfull width of 6.1 m to 8.2 m for RCP4.5 and 10.2 m for RCP8.5. Specific morphological behaviour should be investigated in more detail, particularly to assess if the governing erosion mechanism is seasonally dependent, perhaps incising during spring freshet and widening when the bed is vegetated in the summer.
617

Zhodnocení ekonomické úrovně hlavních kategorií zemědělských podniků v ČR / Assessing the economic level of the main categories of farms in the Czech Republic

Hammerová, Eliška January 2013 (has links)
The aim of this thesis is to evaluate the economic level of Czech farms. To achieve this goal, the standard output indicators will be analyzed according FADN methodology. The analysis will be done according to the main categories of the farms according to type of farming, economic size, legal status and relationship with the LFA. Another goal is to make international comparisons of Czech agriculture with a sample of the European Union countries again by analyzing data from the FADN EU. The main purpose of the international comparison is to highlight the strengths and weaknesses of the Czech agriculture affecting its competitiveness among the EU countries.
618

Řízení po linii výkonů a jeho informační zajištění (na příkladu konkrétního podniku) / Management costing and information assurance (on example of concrete company)

Merunková, Lucie January 2015 (has links)
The aim of the thesis Management costing and information assurance (on example of concrete company) is to evaluate the calculation formula and the calculation system of the selected company and to propose suggestions for improvements. The theoretical part is devoted mainly to well-known methods and principles of calculations. The practival part is devoted directly to Zentiva, k.s. and its particular calculation formula and calculation system. Costing principles are evaluated and suggestions are designed to improve the whole system.
619

Analýza možností řešení výběru reportingových nástrojů / Analysis of possibilities of choice solution of reporting instruments

Hodinka, Pavel January 2010 (has links)
The diploma thesis deals with the selection of tools used for reporting and managerial output for a telecommunications company that, with respect to the volume of its activities, falls into the category of small and medium-sized enterprises. The theoretical part of the thesis focuses on general issues of Business Intelligence, on finding and combining recommendations for high-quality reporting and output, and on the method of choosing the right option meeting the necessary requirements from a wide selection. The practical part describes the reasons that led a specific company to the need for reporting tools. It summarizes the company's needs and analyzes the market of potential products. This part is concluded with a selection procedure that, using the created criteria, assesses individual products and attempts to find the best solution. This thesis is based on theoretical knowledge acquired during studies, as well as practical experience and consultations with experts in reporting. It can also serve to summarize requirements and to find options for companies looking for optimal reporting and output tools.
620

Analýza dopadů větrné energie na hospodaření ČEPSu a dopad rozvojových investic firmy ČEPS na českou ekonomiku / Analysis of the impact of electricity generation from wind on investment activities of CEPS’s company, assessment of the impact of these investments on the Czech economy

Krchová, Eva January 2014 (has links)
The aim of master thesis is to analyze the impact of electricity generation from wind on investment activities of CEPS's company, and also to assess the impact of these investments on the Czech economy. The work familiarizes readers with reasons for the development of the transmission system in the Czech Republic, with the concept of blackout and also with apparatus of assessing the impact of investment on the economy of the selected state -- input-output model analysis. The method used to obtain data for this work is based on the literature review, as well as expert advice on the input-output model, consultation with the experts in CEPS and the data provided by them. The theoretical part deals with Czech transmission system, and it is followed by the development of wind energy construction and the problems associated with it, with blackout and readiness of the Czech Republic to the possible failure in electricity supply. In the practical part, there are measures that are built in order to prevent the risk of blackouts in the Czech Republic, there is a more detailed examination of the Plan of development and rehabilitation of Czech transmission system, and there is also described the process of construction of analytical input-output apparatus for analyzing the impact of CEPS's development investments on the Czech economy, approximated by GDP.

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