• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 112
  • 40
  • 26
  • 22
  • 12
  • 10
  • 9
  • 7
  • 5
  • 4
  • 3
  • 3
  • 3
  • 2
  • 2
  • Tagged with
  • 301
  • 29
  • 26
  • 23
  • 21
  • 20
  • 18
  • 16
  • 14
  • 14
  • 14
  • 13
  • 13
  • 13
  • 12
  • 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

Contemporary financial globalisation in historical perspective : dimensions, preconditions and consequences of the recent and unprecedented surge in global financial activity

Alexandre, Salles January 2008 (has links)
The subject of this thesis is financial globalisation in historical perspective, and its key contribution is to demonstrate the J-curve as an alternative depiction of financial globalisation since the classical Gold Standard period. As a preliminary and essential step, some definitions and clarifications on globalisation are provided in a literature review. Then, fundamental issues are considered to assess financial globalisation, so that both the goals and the boundaries of the thesis are clearly stated. Throughout the historical period in debate, there were two waves of financial globalisation: the first one occurring during the 1870-1914 period, and the second lasting from the end of the Bretton Woods agreements until the present day. The dominant approach in economics asserts that the degree of commercial and financial integration corresponds over time to a U-shaped pattern, i.e. markets presented high levels of integration during the forty years before WWI. Then, this integration collapsed in the years between the wars, recovering gradually after the Bretton Woods agreements until it reached again in the 1990s the same pre-1914 level of integration. The thesis approaches this model focusing on the financial side. Then, according to the U-curve, contemporary financial globalisation is not unprecedented. This thesis proposes an alternative view. In contrast to the mainstream U-curve, the empirical data provided indicates that today’s financial integration is unprecedented and more pervasive in some key financial markets than it was during the pre-1914 era. The empirical evidence provided proposes that a J-shaped pattern is a more appropriate way to interpret how financial markets have evolved since the late 19th century. The Jshape suggests that in some financial achieved a huge surge from the 1990s to 2005, surpassing the previous level of integration. So, in these markets, contemporary financial globalisation is unprecedented from the 1990s onwards. The J-curve does not mean that all financial markets became more globalised during the late 20th century in comparison to the Gold Standard era, but only some that presented the U-shape from 1870 to 1995. Qualitative aspects of the J-curve are examined. The different institutional frameworks underlying each historical period are discussed revealing that new institutional arrangements, policy changes, technological advances in ICT and a wide range of financial innovations are the key driving forces that have spurred today’s financial globalisation to higher levels than in the past. Finally, the last chapter assesses the key macroeconomic implications of this new era for the world economy.
2

The dynamics of a multi-axis, vibratory rate gyroscope

Eley, Rebecka January 2000 (has links)
No description available.
3

Assembly line balancing using hybrid genetic algorithms

Mapfaira, Herbert January 2002 (has links)
No description available.
4

A Novel Method for Manufacture of the Wedge-Shaped Fiber Array

Yin, Tseng-Hung 09 September 2005 (has links)
Here choose wedge-shaped fiber, which have sample shape, low manufacture cost and time, to manufacture wedge-shaped fiber array in the paper. In order to reduce cost, it depends on change and reduce manufacture process steps.
5

A design perspective on shaping possibilities with new technology v bed knitting machines

Guy, Katherine January 2001 (has links)
No description available.
6

Macromolecular Engineering of Cyclic Aliphatic Polyesters

Li, Haiying 25 January 2007 (has links)
Summary of the thesis This works aims at reporting a novel strategy that combines controlled ring-opening polymerization of lactones initiated by a cyclic tin(IV) dialkoxide and intramolecular cyclization by photo-cross-linking of pendant unsaturations next to the propagating sites. No linear species is ever involved in the polymerization, which allows higher molecular weight macrocycles to be prepared with high efficiency. Moreover, the synthetic route is very flexible to the point where macrocyclic polyesters with more complex although well-defined architectures, such as tadpole-shaped and sun-shaped copolyesters, can be tailored. Synthesis of well-defined star- and eight-shaped polyesters and twin tadpole-shaped amphiphilic copolymers has also been explored by using a spirocyclic tin(IV) alkoxide as initiator.
7

Photophysics of linear and star-shaped oligofluorenes and their application in lasers

Montgomery, Neil A. January 2013 (has links)
This thesis presents a study of the photophysical properties of a number of fluorene molecules used for organic semiconductor lasers. These results are then combined with lasing results to assess what the important properties in an organic semiconductor laser material are. Photophysical measurements were performed on a family of oligofluorenes; results show a redshift in the peak absorption and emission wavelengths with increasing length. There is also an increase in the molar extinction coefficient and photoluminescence quantum yields of the molecules. Transition dipole moments also increase with length, but fluorescence scales slower than absorption due to self-trapping occurring at longer molecular lengths. This study was then expanded to two families of star-shaped molecules with fluorene arms and differing cores. These molecules have three arms connected to either a central benzene unit or a larger truxene core. These molecules show an increase in PLQY and roughly three times higher molar extinction coefficients than comparable linear oligofluorenes. The star-shaped molecules PLQY and transition dipole moments are both greater than their linear oligofluorene counterparts. Energy transfer was then studied in the truxene-cored molecules, which showed that the symmetry of the molecule was broken due to interactions with the solvent. Energy transfer was observed on two timescales; a fast 500 fs process which is attributed to a localisation onto a single arm to emit, and a 3-10 ps second decay component, and was assigned to resonant energy transfer between the arms. Both decays were found to be wavelength dependent. Lasing results were then obtained for the benzene cored molecules. It was found that star-shaped molecules present improved lasing characteristics with lower ASE and lasing thresholds. These results were compared with those obtained for truxene-cored molecules whose rigid core provides them with better lasing and ASE characteristics.
8

Ground Antennas for Slim Handsets

CHU, FANG-HSIEN 20 August 2012 (has links)
In this dissertation, multiband ground antennas for slim handsets are presented. The design techniques are on efficiently exciting the resonant modes of the system ground plane of the handset to greatly enhance the antenna¡¦s operating bandwidth. The first antenna design is a monopole antenna integrated with a slot antenna formed in a clearance in the system ground plane to enhance the bandwidth of the antenna¡¦s lower band for penta-band WWAN operation. The second antenna design uses a shaped circuit board with a proper notch embedded therein to result in stronger surface current excitation in the ground plane, which leads to bandwidth enhancement in the antenna¡¦s lower band and upper band. The second antenna design can cover seven-band WWAN/LTE operation. The antenna geometry in the second antenna design is further applied in the third antenna design. In order to meet the practical application of slim handsets, the third antenna design is integrated with a battery element and a metal midplate to decrease the thickness of the handset. The third antenna design can cover seven-band WWAN/LTE operation. Finally, the simulated SAR and HAC results are analyzed for the three proposed antennas.
9

Frequency Shaped LQR Design of an Active Noise Cancellation Headphone

Lin, Tsai-Fu 26 August 2009 (has links)
The purpose of this thesis is to design and implement an active noise cancellation headphone (ANC) with a feedback controller optimally designed using the linear quadratic regulator (LQR) design approach. The controller compares the audio input signal with the measured signal from a mini microphone in the headphone, and attempts to generate a control signal so that the headphone may reproduce a clean, low noise audio sound, without being interfered by the environmental noise. The control bandwidth of the ANC headphone is 100~600Hz. The controller design emphasizes the choice of a weighting function in shaping the controller gain at different frequencies, so as to achieve maximum in-band noise cancellation and low noise amplification outside the bandwidth. The experimental result shows achievable noise cancellation of maximum 25dB within the control bandwidth and a barely noticeable slight noise amplification of maximum 6dB at high frequencies and 4.5dB at inaudible low frequencies.
10

An Aperture Synthesis Technique for Cylindrical Printed Lens/Transmitarray Antennas with Shaped Beams

Biswas, Mahmud 27 June 2013 (has links)
Printed lens antennas offer the possibility of realizing shaped beam patterns using no more complexity than is required for pencil beam patterns. Shaped beam patterns can be obtained by appropriately determining the complex transmission coefficient required for each cell (or element) of the printed lens, taking into account the varying feed field over the input surface of the lens. Certain ranges of transmission coefficient amplitude and phase are undesirable (eg. too low an amplitude implies a large reflection at the lens input surface). It would be preferable to constrain the range of values that the transmission coefficient can take as an integral part of the lens synthesis procedure, and thus the transmission coefficient itself needs to be the synthesis variable. In this thesis a synthesis technique for doing this is developed based on the method of generalized projections, modified to “operate” in the space of transmission coefficients. This makes it possible to immediately perceive what influence constraints on the actual transmission coefficients have on the possible radiation pattern performance. In addition, an approach that allows one to constrain the transmission coefficient to values that must be selected from an available database of transmission coefficients is incorporated into the synthesis technique.

Page generated in 0.0422 seconds