• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 4071
  • 1867
  • 513
  • 276
  • 238
  • 219
  • 134
  • 111
  • 84
  • 84
  • 61
  • 53
  • 53
  • 38
  • 35
  • Tagged with
  • 8629
  • 2085
  • 1831
  • 1826
  • 1210
  • 1202
  • 1181
  • 1018
  • 727
  • 719
  • 678
  • 534
  • 462
  • 429
  • 366
  • 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.
11

On the relation between density and index of refraction of air ... /

Gale, Henry Gordon, January 1900 (has links)
Thesis (Ph. D.)--University of Chicago. / "Reprinted from the Physical review, Vol. XIV, No. 1, January, 1902." Includes bibliographical references. Also available on the Internet.
12

The Development and Evaluation of an index language for energy research [Volume 2]

Blomkamp, Yvonne 29 September 2023 (has links) (PDF)
Although numerous dictionaries of energy terms are available, and there are other thesauri on specific aspects of energy, for example, coal, biomass, nuclear energy, there are few comprehensive energy thesauri. So far, no energy thesaurus applicable to South Africa, has been published. It was found that energy terms in the US. Department of Energy's Energy Data Base: Subject Thesaurus are used in a different context to South Africa. The United Kingdom in - turn, used terms in a different context to the United States . In order for there to be effective cooperation between information centres engaged in the collection, storage and . dissemination of energy-related information in South Africa, a need was perceived for the definition and standardisation of the terms and concepts used in the energy field. In recognition of this need, the CSIR provided funds for a year to develop an energy thesaurus relevant to South Africa. As the Energy Research Institute at the University of Cape Town had the most developed energy information system in South Africa at the time, the vocabulary from the Institute's energy database was used as the base from which the thesaurus was constructed. The database contained information considered to be most representative of the main areas of research in the energy field in South Africa. Compilation was undertaken with the assistance and cooperation of the research staff at the Institute. The core area of the thesaurus is the energy field, with an emphasis on energy technology, energy research and development, energy sources, energy resources and reserves, and energy utilisation. A special emphasis is placed on alternative energy, which includes appropriate technology and alternative fuels. The fringe areas of the thesaurus are economics, engineering, and air pollution. The thesaurus has been designed for use mainly in a computerised information system, although it could be made available for use in a manual system. In a computerised system, it is hoped that, built into the system, it could be used for reference as an online aid to both indexers and searchers. It must be emphasised that this will not exclude the use of natural or free language in searching. Thus, the thesaurus can be used as a guide if and when required.
13

Novel approaches to the analysis of generalised bandit problems

Crosbie, James January 1997 (has links)
No description available.
14

The Z-Semimagic of Some Graphs

Huang, Shao-lun 22 August 2011 (has links)
We call a finite simple graph G = (V (G),E(G)) to be Z-semimagic if it admits an edge labeling l : E(G) ¡÷ Z {0} such that the induced vertex sum labeling l+(v) = uv∈E(G) l(uv) is constant. The constant is called a semimagic index, or an index for short, of G under the labeling l. We consider the set of all possible semimagic indices r such that G is Z-semimagic with a semimagic index r, and denote it by IZ(G). We call IZ(G) the index set of G with respect to Z. In this thesis, we decide the index set IZ(G) for G being regular graphs, complete bipartite graphs, wheel graphs and fan graphs. Also, we determine whether 0 ∈ IZ(G) for G being complete multi-partite graphs.
15

The Hong Kong stock index futures market /

Wan, Hon-kuen, Francis. January 1987 (has links)
Thesis (M.B.A.)--University of Hong Kong, 1987. / Cover title.
16

Fundamentální indexování / Fundamental indexing

Chytrý, Martin January 2009 (has links)
The paper deals with stock market indices. It reveals the flaws inherent in traditional market capitalization weighted indices, that causes a return drag. At the same time it shows how you can get rid of these flaws by using fundamental indices, and gives proofs about their superiority. The practical part focuses on building fundamental indices of czech stocks traded on the Prague Stock Exchange, dealing with historical data. It empirically demonstrates their outperformance of a benchmark market capitalization weighted index.
17

Indices for generalised forms of bandit problem

Greatrix, Simon Gregory John January 1995 (has links)
No description available.
18

Characteristics, Applications, and Properties of Carbon-Dioxide-Laser-Induced Long-Period Fiber Gratings

Bachim, Brent Leland 23 June 2005 (has links)
Long-period fiber gratings (LPFGs) are typically fabricated by exposing photosensitive optical fiber to ultraviolet light. However, LPFGs can be fabricated by a variety of other techniques, including exposure to carbon-dioxide (CO2) laser light. The physical process by which the refractive-index change is induced in an optical fiber during exposure to CO2 laser light gives CO2-laser-induced LPFGs unique properties when compared to more traditional LPFGs fabricated by exposure to UV light. As such, CO2-laser-induced LPFGs respond differently to external perturbations and useful behavior has been observed, including variable attenuation tuning at a constant wavelength and wavelength tuning at constant amplitude with applied flexure. In order to manipulate, harness, and enhance the unique features of CO2-laser-induced LPFGs, it is necessary to understand their physical properties and optical characteristics. The main objectives of the research presented in this thesis are to quantify experimentally the optical performance of CO2-laser-induced LPFGs with respect to flexure, torsion, and variable incident polarization, to characterize grating cross-sectional refractive-index profiles, and to demonstrate applications of CO2-laser-induced LPFGs that exploit their unique properties. As part of the investigation of the effects of asymmetry, the fabrication and basic transmission characteristics of CO2-laser-induced LPFGs were examined. The polarization-dependent transmission characteristics, specifically polarization-dependent loss and polarization mode dispersion, of CO2-laser-induced LPFGs were investigated. The unique behavior of the gratings in response to applied flexure and applied torsion was also explored. Example variable optical attenuator, optical tunable filter, and fiber-to-waveguide coupler devices illustrate the potential advantages of the asymmetric index profile present in CO2-laser-induced LPFGs for certain applications. A new cross-sectional refractive-index profiling technique was presented that enables measurement of profiles containing small and irregular index variations. The profiling technique was used to measure the cross-sectional refractive-index profiles of optical fiber exposed to CO2 laser light. Future areas of research concerning CO2-laser-induced LPFGs were identified and discussed.
19

Clear Sky Index : Framtagen med enkortsdator och webbkamera

Enström, Oskar, Klavebäck, Erik, Muhrbeck, Rasmus January 2015 (has links)
A future sustainable society need to rely more on renewable energy sources. One of the most promising alternatives is solar power. However, there are inherent fluctuations accompanied with solar power, for example if the shadow of a cloud blocks the sun light on a whole solar cell it will not produce any power. This will cause problems with connecting the solar panels to the power grid. Clear sky index (CSI) is a measurement of how much of the sky that is covered by clouds, and is a key parameter for planning of large scale solar panels. This report describes the manufacturing and programming of a cheap device for calculating the so called clear sky index (CSI) over a large portion of the sky. The device contains a Raspberry PI computer with a camera module, and utilize a program that through the computer-vision library OpenCV can calculate the CSI of the images provided by the camera. The resulting prototype costs about 800 SEK, and has possibility to be improved by adding a fish-eye lens to cover a bigger area, or to be water resistant by improving the casing, without exceeding a 1000 SEK price tag.
20

Combined Use of Vegetation and Water Indices from Remotely-Sensed AVIRIS and MODIS Data to Monitor Riparian and Semiarid Vegetation

Kim, Ho J January 2006 (has links)
The objectives of dissertation were to examine vegetation and water indices from AVIRIS and MODIS data for monitoring semiarid and upland vegetation communities related with moisture condition and their spatial and temporal dependencies in estimating evapotranspiration (ET). The performance of various water indices, including the normalized difference water index (NDWI) and land surface water index (LSWI), with the chlorophyll-based vegetation indices (VIs), the normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI) was evaluated in 1) investigating sensitivity of vegetation and land surface moisture condition 2) finding optimal indices in detecting seasonal variations in vegetation water status at the landscape level, and 3) their spatial and temporal scale dependency on estimating ET. The analyses were accomplished through field radiometric measurement, airborne-based and satellite data processing accompanied with water flux data.The results of these studies showed vegetation and landscape moisture condition could be identified in VI - WI scatter-plot. LSWI (2100) showed the biggest sensitivity to variation of vegetation and background soil moisture condition as well. Multi-temporal MODIS data analysis was able to show water use characteristic of riparian vegetation and upland vegetation. Results showed water use characteristics of riparian vegetation are relatively insensitive to summer monsoon pulse, while upland vegetation is highly tied to summer monsoon rain. The relationship between water flux measurement from eddy covariance tower and satellite data has shown that MODIS derived EVI and LSWI (2100) have similar merit to estimate ET rate, but better correlation was observed from the relationship between MODIS EVI and ET.Pixel aggregation results using fine resolution AVIRIS data showed moderate resolution spatial scale 250m or 500m, best predicted ET rates over all study areas. Surface fluxes temporally aggregated to weekly or biweekly intervals showed the strongest ET versus EVI relationships. ET measured at flux towers can be scaled over heterogeneous vegetation associations by simple statistical methods that use meteorological data and flux tower data as ground input, and using the MODIS Enhanced Vegetation Index (EVI) as the only source of remote sensing data.

Page generated in 0.0423 seconds