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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.
51

All Digital Frequency Synthesizer Using Flying Adder Architecture and Low Power Low Latency 2-dimensional Bypassing Signed Multiplier

Lu, Yu-cheng 06 July 2009 (has links)
This thesis includes two topics. The first topic is an ADFS¡]All Digital Frequency Synthesizer¡^using a Flying Adder architecture. The second one is a low-power and low-latency 2-dimensional bypassing signed multiplier. In the first topic, the ADFS is implemented by only using the standard cell library of TSMC¡]Taiwan Semiconductor Manufacturing Company¡^0.18 £gm 1P6M CMOS process. The turn-around time is effectively reduced. Furthermore, the portability and reusability of the proposed design is significantly enhanced. The design provides stable clock signals with fast switching time. In the second topic, the proposed multiplier is carried out by Baugh-Wooley algorithm using 2-dimensional bypassing units. The proposed bypassing units automatically skip redundant signal transitions when either the horizontally¡]row¡^partial products or vertically¡]column¡^operands are zero.
52

Economic Impacts of Sport Events : Case study of The European Championships in Figure Skating Malmö City 2003

Nordin , Lina January 2008 (has links)
<p> <strong>Abstract</strong><p>This thesis is based on two questions: What are the differences in the outcome of a sport event depending on the choice of method to be used for evaluation? And what method is the most appropriate one in terms of evaluation of the economic effects of sport events? There are two methods used: and the first one is the traditional multiplier analysis and the second method used is introduced by Braunerhielm and Andersson (2007). The economic results of the two different methods used in this thesis have been applied on a real life event, The European Championships in Figure Skating in Malmo City 2003. The two methods is of great importance and they provide us with two suggested results that are of interest, but what method to be used depends on who is making the evaluation and for what purpose. The suggested method by Braunerhielm and Andersson (2007) results in an outcome representing the economic effects of the event concerning all areas in the municipality involved both the private sector and the public sector. This method is of best use for athlete organizations that wants to keep a continuous record of their contribution towards the municipality through events and the positive result will help them promote their importance of existence to the municipality so that they can get public funding for arranging future events and gain more profit by increasing the interest of their association. Whereas,the multiplier analysis is appropriate to use for the municipality, as the results is the tax revenue gained from the event that is to be reinvested in e.g. new schools or roads the result will then help promoting the public funding of sport events to the public. The appropriate method to use is the multiplier analysis as it generates results that is of interest for the public as it calculates the effect for the municipality as a whole and not only the effects for the once directly involved in the sport event.</p></p><p> </p>
53

Essays on Macroeconomics and Finance

Mendel, Joshua Brock January 2013 (has links)
The Local Multiplier: Theory and Evidence. I show that 1) the policy-relevant "global multiplier" can be written as the sum of a spending component and a taxation component, all scaled up by spillover effects, 2) the "local multiplier" is exactly the spending com- ponent, and 3) if trade is anonymous, the local effects of a shock to federal government purchases in a county will be identical to the effects of a shock to consumer demand for the exports of that locality. I estimate a bound for the local multiplier and consider spillover effects to contiguous counties. I find that a shock of $48,000 creates at least one job-year locally. Analysis at a monthly frequency suggests that these jobs are more persistent than previously estimated. Evidence of higher multipliers in recessions is mixed. / Economics
54

Modelling, Optimisation and Advanced Duty Detection in a Mining Machine

Charles Mcinnes Unknown Date (has links)
This thesis presents advanced algorithms for realtime detection of dragline duty, the quantification of its causes and the combined optimisation of dragline motion to minimise cycle time and duty. Draglines are large, powerful, rotating, multibody systems that operate in a similar manner to cranes and certain pick and place robots. Duty is an estimate of fatigue damage on the dragline boom caused by cyclic stresses that are associated with the repetitive dig and dump operation. Neither realtime detection of duty nor the quantification of its causes were previously available. In addition, no previous researchers have optimised the dynamic motion of mining equipment to achieve the combined maximisation of productivity and minimisation of maintenance measures. The advanced duty detection system was developed to improve feedback to dragline operators. The algorithms that were developed are based on the mechanics of dragline motion and fatigue. In particular, fatigue cycles in measured stress are identified at the earliest possible time, based on a novel proof and modification to the rainflow cycle counting algorithm. The contributions of specific causes to each individual stress range are quantified based on the mechanics of operator dependent control and dragline dynamics. In this manner, specific causes of duty are measured. The algorithms confirmed the significant contribution from operator dependent factors and identified the major causes, attributing 28% of the total duty to out-of-plane bucket motion and 15% to dynamic vibration. Further improvements to dragline performance required the development of a dragline dynamic model for offline testing and optimisation. A complete, condensed set of equations for a four-degree-of-freedom nonlinear coupled model of a dragline was derived using Lagrange’s method, allowing direct insight into dragline behaviour not available from previous research. The model was used to investigate the relationship between motor power, operator behaviour, bucket trajectory, productivity and duty during the swing and return phases of operation. Significant potential for increasing productivity and reducing duty was demonstrated. The advanced duty detection system and the dragline model were validated with field measured data, video footage, alternative modelling and expert review. Realtime and end-of-cycle feedback was simulated over many cycles of measured data. Experts from industry and research were consulted to verify the causes of duty based on detailed measured data analysis. The forces, stresses and out-of-plane angle predicted by the dragline model were closely compared with measured data over various indicative cycles. The dragline model was also validated against an alternative model constructed in ADAMS. The development of the dragline model enabled model-based numerical optimisation. Significant nonlinearities in the model and the constraints necessitated the use of the Lagrange multiplier method. The bucket trajectory during the swing and return phase was directly optimised. In order to minimise cycle time and duty, a penalty for duty incurred was added to the cycle time, effectively maximising long-term productivity. For a slew torque optimisation scenario using measured rope lengths, the numerical optimisation performance was shown to be 10-30% better than manual optimisation and 50-60% better than the operator performance. This thesis outlines several significant contributions to improving dragline performance. Underpinning the advanced duty detection system are three significant contributions to fatigue cycle counting algorithms: a proof of the equivalence of two pre-existing algorithms; a new algorithm that enables realtime detection of duty; and an algorithm that can attribute duty to specific causes. These novel feedback tools can provide realtime operator feedback and identify the causes of excess duty and when it was incurred. A complete and condensed set of equations for the four-degree-of-freedom model enabled, for the first time, the optimisation of dragline operation to concurrently reduce duty and increase productivity. The models and feedback algorithms were validated with field measured data. Future work could include installation and extension of the advanced duty detection system. In addition, further modelling and optimisation research could focus on improving the heuristics used for bucket trajectory control, realtime determination of optimum bucket trajectory and testing proposed dragline modifications.
55

Broadband Schottky diode components for millimeter-wave instrumentation

Viegas, Colin January 2017 (has links)
Terahertz source technology has been an active area of research for a number of years. This has helped develop continuous wave solid-state sources that are highly desirable in a wide range of applications spanning from Earth science to medical science. However, even with advances in terahertz technology, the generation of fundamental source power at these frequencies is still challenging. Promising electronic solid-state devices fall short in overcoming source power shortage due to electronic breakdown mechanism and fabrication limits at terahertz frequencies. The fundamental physical limitation of photonic devices, such as low photon energy, force cryogenic operation which at times is impractical. Schottky diode frequency multipliers often offer a very practical solution for generating continuous wave radiation based on solid-state technology. This harmonic source technology is today a most certain candidate for many applications where compactness and room temperature operation is desired. However, despite of all the advances in Schottky diode fabrication and their use in frequency multiplication, output power falls rapidly with increasing frequency. Thermal constrains, fabrication limits, assembly errors and parasitic losses all constitute changes that affect the performance of these devices and make it difficult to reproduce experimental data. To overcome these problems and progress towards the generation of milliwatts of power at terahertz frequencies, the study of existing methods to generate and handle high power is necessary. In the first part of the thesis, the design, fabrication and development of two Schottky diode-based frequency doublers is discussed. The work focuses on the generation of high-power sources that are capable of handling higher input powers while maintaining good thermal efficiencies. A detailed study into the machining tolerances, assembly errors and temperature effects are evaluated for the frequency doublers. High frequency effect such as velocity saturation is also addressed. Depending on the design frequency and power handling, two different circuit configurations are employed for the frequency doublers. While the high-power 80/160 GHz frequency doubler used a discrete flip-chip diode configuration, the 160/320 GHz frequency doubler employed an integrated diode membrane to mitigate sensitivity issues encountered during assembly and enable correlation between simulated and measured data. The second part proposes the use of millimeter-wave Schottky diode-based radiometers for imaging of composites samples. The focus of this experiment is the introduction of an alternate EM inspection method with the use of broadband Schottky diode components. This technique combines two different fields {--} non-destructive testing and radiometry, which presents a potentially new and interesting area for research. Since no single method can qualify to be the most accurate for all inspections, and with the future integration bringing down manufacturing costs of high frequency components, this demonstration presents a new approach to consider for future material imaging and evaluation experiments.
56

We just estimated twenty million fiscal multipliers

Capek, Jan, Crespo Cuaresma, Jesus 08 1900 (has links) (PDF)
We analyse the role played by data and specification choices as determinants of the size of the fiscal multipliers obtained using structural vector autoregressive models. The results, based on over twenty million fiscal multiplier estimated for European countries, indicate that many seemingly harmless modelling choices have a significant effect on the size and precision of fiscal multiplier estimates. In addition to the structural shock identification strategy, these modelling choices include the definition of spending and taxes, the national accounts system employed, the use of particular interest rates or inflation measures, or whether data are smoothed prior to estimation. / Series: Department of Economics Working Paper Series
57

Testování metody tržního porovnání na softwarových firmách s využitím regresních rovnic pro odhad tržních multiplikátorů / Testing market approach using regression equations to estimate the market multipliers for software companies

Tůma, Pavel January 2008 (has links)
Ph.D. thesis deals with testing precise use market approach to the valuation of software companies. Contains justification for the need of dealing with less traditional valuation methods, theoretical approaches for the use of market multipliers and existing knowledge to regression analysis is used to explain the multipliers. The analytical part is assembled its own regression equation to determine the multiplier in the years 2004-2010, the usability was tested in comparison with the use of a multiplier based on the median level of comparable sample of firms. There was also objective to determine the preferred type multiplier for software companies, which can be used e.g. when using scoring methods to adjust the multiplier. Complementing the thesis was to compare the quality of its own regression equations and equations published by Professor Damodaran. In most years through its own regression equations managed to establish a more precise multiplier than was achieved by using the mean value of a comparable sample of firms. We were also able, in most years to find suitable regression equation than the equation published by Professor Damodaran. Type multiplier P/E appeared to be significantly better to explain the regression equation in comparison with the other types of multiplier.
58

Analogové funkční převodníky pro laboratorní výuku / Analog nonlinear function structures for educational laboratory purposes

Filko, Patrik January 2019 (has links)
This master’s thesis deals with the design and the realization of a laboratory teaching device, which includes two-port parts with nonlinear transmission characteristics corresponding to quadratic, inverse quadratic and cubic functions. It also includes a more complicated design of a polynomial function converter that offers students a practical view of functions mathematically designed while verifying their accuracy in laboratory exercises. The whole concept is supported by the design of the power supply circuit and the harmonic signal generator. The individual features of this project are feasible from components commercially available.
59

Development of a Thick Gas Electron Multiplier Detector for Microdosimetry

Orchard, Gloria M. 12 1900 (has links)
<p> In experimental microdosimetry one of the goals is to measure the absorbed dose in microscopic volumes of tissue. The traditional spherical tissue-equivalent proportional counter (TEPC) is the most common detector currently used for microdosimetry. A new microdosimetric detector based on a thick gas electron multiplier (THGEM) was developed. To investigate the feasibility of the THGEM type detector for microdosimetry, a prototype detector was designed and manufactured. The THGEM detector is robust, easy to manufacture and is cost effective. The THGEM foil is composed of a thin FR4-epoxy insulator coated with copper on both sides. The THGEM contains 32 holes each with a diameter of 0.35 mm and pitch of 0.64 mm. The sensitive volume of the detector is a right cylinder with a diameter of ~5 mm and height of ~5 mm and is located in the center of the detector. Systematic tests were conducted at the McMaster Accelerator Laboratory to investigate its overall performance. A neutron-gamma ray radiation field was generated using the 7Li(p,n) reaction. The detector was operated at low bias voltages initially to test the stability and then the relative multiplication gain was measured as a function of the operating high voltage. The detector performance was observed with different THGEM insulator thicknesses ranging from 0.12 mm to 1.48 mm. The multiplication gain was assessed and both neutron and gamma-ray radiation was detected by the THGEM detector. The spectra obtained with the THGEM detector were analyzed and compared to the data collected with the standard spherical TEPC. The investigations provided information about the THGEM detector operation for microdosimetry and the THGEM microdosimetric spectra observed are comparable to the standard TEPC data.</p> / Thesis / Doctor of Philosophy (PhD)
60

Precision Tunable Hardware Design

Nayak, Ankita Manjunath January 2016 (has links)
No description available.

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