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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.
91

ACTS radiometers and a comparison of atmospheric attenuation derived form temperature-humidity and radiometric data

Evers, Brent A. 04 December 2009 (has links)
Virginia Tech has recently developed and constructed seven ground terminals for use in a propagation experiment employing the Advanced Communications Technology Satellite. This satellite was deployed by NASA in September of 1993. The ground terminals are used in the study of propagation effects caused by the atmosphere for 20 and 30 GHz signals. Each of these terminals contains one total power radiometer for each frequency. These radiometers are used to set clear sky attenuation reference levels for satellite beacon calibration. This thesis describes the design, implementation and testing of the radiometers built at Virginia Tech. In addition, a mathematical algorithm used for the prediction of clear sky attenuation along satellite paths is tested for correlation with radiometer predicted clear sky attenuation. Test data is compared to determine if the algorithm might serve as a radiometer replacement in future propagation experiments or other applications. / Master of Science
92

Effects of a dialogical argumentation based instruction on grade 9 learners' conceptions of a meteorological concept: Cold Fronts in the Western Cape, South Africa.

Riffel, Alvin Daniel January 2012 (has links)
<p>&nbsp / </p> <div style="line-height: 150% / margin: 0cm 0cm 12pt"><span style="line-height: 150% / font-size: 12pt"><span style="line-height: 115% / font-family: &quot / Calibri&quot / ,&quot / sans-serif&quot / font-size: 12pt / mso-ansi-language: EN-US / mso-fareast-font-family: Calibri / mso-bidi-font-family: 'Times New Roman' / mso-fareast-language: EN-US / mso-bidi-language: AR-SA" lang="EN-US"> <div style="line-height: 150% / margin: 0cm 0cm 12pt"><span style="line-height: 150% / font-size: 12pt">This study looks at the effects of a dialogical argumentation instructional model (DAIM) on grade 9 learners understanding of selected meteorological concepts: Cold fronts in the Western Cape of South Africa. Using a quasi-experimental research design model, the study employed both quantitative and qualitative (so-called &lsquo / mixed methods&rsquo / ) to collect data in a public secondary school in Cape Town, in the Western Cape Province. A survey questionnaire on attitudes and perceptions towards high school as well as conceptions of weather was administered before the main study to give the researcher baseline information and to develop pilot instruments to use in the main study.</span></div> <div style="line-height: 150% / margin: 0cm 0cm 12pt"><span style="line-height: 150% / font-size: 12pt">&nbsp / The study employed a dialogical instructional model (DAIM) with an experimental group of learners exposed to the intervention, and recorded differences from a control group which had no intervention. Learners from the two groups were exposed to a meteorological literacy test evaluation before and after the DAIM intervention. The results from the two groups were then compared and analysed according to the two theoretical frameworks that underpin the study namely: Toulmin&rsquo / s Argumentation Pattern - TAP (Toulmin, 1958) and Contiguity Argumentation Theory - CAT (Ogunniyi, 1997).</span></div> <span style="line-height: 115% / font-size: 12pt">&nbsp / Further analyses were conducted on learners&rsquo / beliefs and indigenous knowledge, according to their conceptual understanding of weather related concepts used in the current NCS (National Curriculum Statement).&nbsp / After completing the study some interesting findings were made and based on these findings certain recommendations were suggested on how to implement a DAIM-model into classroom teaching using Indigenous Knowledge (IK). These recommendations are suggestions to plot the way towards developing a science&ndash / IK curriculum for the Natural Sciences subjects in South African schools. </span></span></span></div>
93

Effects of a dialogical argumentation based instruction on grade 9 learners' conceptions of a meteorological concept: Cold Fronts in the Western Cape, South Africa.

Riffel, Alvin Daniel January 2012 (has links)
<p>&nbsp / </p> <div style="line-height: 150% / margin: 0cm 0cm 12pt"><span style="line-height: 150% / font-size: 12pt"><span style="line-height: 115% / font-family: &quot / Calibri&quot / ,&quot / sans-serif&quot / font-size: 12pt / mso-ansi-language: EN-US / mso-fareast-font-family: Calibri / mso-bidi-font-family: 'Times New Roman' / mso-fareast-language: EN-US / mso-bidi-language: AR-SA" lang="EN-US"> <div style="line-height: 150% / margin: 0cm 0cm 12pt"><span style="line-height: 150% / font-size: 12pt">This study looks at the effects of a dialogical argumentation instructional model (DAIM) on grade 9 learners understanding of selected meteorological concepts: Cold fronts in the Western Cape of South Africa. Using a quasi-experimental research design model, the study employed both quantitative and qualitative (so-called &lsquo / mixed methods&rsquo / ) to collect data in a public secondary school in Cape Town, in the Western Cape Province. A survey questionnaire on attitudes and perceptions towards high school as well as conceptions of weather was administered before the main study to give the researcher baseline information and to develop pilot instruments to use in the main study.</span></div> <div style="line-height: 150% / margin: 0cm 0cm 12pt"><span style="line-height: 150% / font-size: 12pt">&nbsp / The study employed a dialogical instructional model (DAIM) with an experimental group of learners exposed to the intervention, and recorded differences from a control group which had no intervention. Learners from the two groups were exposed to a meteorological literacy test evaluation before and after the DAIM intervention. The results from the two groups were then compared and analysed according to the two theoretical frameworks that underpin the study namely: Toulmin&rsquo / s Argumentation Pattern - TAP (Toulmin, 1958) and Contiguity Argumentation Theory - CAT (Ogunniyi, 1997).</span></div> <span style="line-height: 115% / font-size: 12pt">&nbsp / Further analyses were conducted on learners&rsquo / beliefs and indigenous knowledge, according to their conceptual understanding of weather related concepts used in the current NCS (National Curriculum Statement).&nbsp / After completing the study some interesting findings were made and based on these findings certain recommendations were suggested on how to implement a DAIM-model into classroom teaching using Indigenous Knowledge (IK). These recommendations are suggestions to plot the way towards developing a science&ndash / IK curriculum for the Natural Sciences subjects in South African schools. </span></span></span></div>
94

Effects of a dialogical argumentation based instruction on grade 9 learners’ conceptions of a meteorological concept: cold fronts in the Western Cape, South Africa

Riffel, Alvin Daniel January 2012 (has links)
Magister Educationis - MEd (Mathematics and Science Education) / This study looks at the effects of a dialogical argumentation instructional model (DAIM) on grade 9 learners understanding of selected meteorological concepts: Cold fronts in the Western Cape of South Africa. Using a quasi-experimental research design model, the study employed both quantitative and qualitative (so-called ‘mixed methods’) to collect data in a public secondary school in Cape Town, in the Western Cape Province. A survey questionnaire on attitudes and perceptions towards high school as well as conceptions of weather was administered before the main study to give the researcher baseline information and to develop pilot instruments to use in the main study. The study employed a dialogical instructional model (DAIM) with an experimental group of learners exposed to the intervention, and recorded differences from a control group which had no intervention. Learners from the two groups were exposed to a meteorological literacy test evaluation before and after the DAIM intervention. The results from the two groups were then compared and analysed according to the two theoretical frameworks that underpin the study namely: Toulmin’s Argumentation Pattern - TAP (Toulmin, 1958) and Contiguity Argumentation Theory - CAT (Ogunniyi, 1997). Further analyses were conducted on learners’ beliefs and indigenous knowledge, according to their conceptual understanding of weather related concepts used in the current NCS (National Curriculum Statement). After completing the study some interesting findings were made and based on these findings certain recommendations were suggested on how to implement a DAIM-model into classroom teaching using Indigenous Knowledge (IK). These recommendations are suggestions to plot the way towards developing a science–IK curriculum for the Natural Sciences subjects in South African schools.
95

Měření meteorologických veličin / Meteorological quantities measurement

BEZDĚKA, Vladimír January 2007 (has links)
The thesis consists of 95 pages and 41 pages of enclosure. Pictures, charts and colour graphs are included. The thesis and the enclosure contain data presented in charts and from the charts graphs have been made. Also, internal material provided by the Czech Hydrometeorological Institute, České Budějovice 7, Antala Staška 1177/32 is incorporated, as well as data from two amateur weather-stations situated in České Budějovice and Hluboká nad Vltavou. The objective of this work is to explain and describe measuring apparatus and methods used in meteorology. The work also compares results gained from a professional weather-station with those from an amateur one.
96

Information Technology Implementation Decisions to Support the Kentucky Mesonet

Grogan, D. Michael 01 April 2010 (has links)
The Kentucky Mesonet is a high-density, mesoscale network of automated meteorological and climatological sensing platforms being developed across the commonwealth. Data communications, collection, processing, and delivery mechanisms play a critical role in such networks, and the World Meteorological Organization recognizes that “an observing system is not complete unless it is connected to other systems that deliver the data to the users.” This document reviews the implementation steps, decisions, and rationale surrounding communications and computing infrastructure development to support the Mesonet. A general overview of the network and technology-related research is provided followed by a review of pertinent literature related to in situ sensing network technology. Initial infrastructure design considerations are then examined followed by an in-depth review of the Mesonet communications and computing architecture. Finally, some general benefits of the Mesonet to the citizens of Kentucky are highlighted.
97

Meteorologically adjusted trends of ozone and dispersion of air pollutants in the Hsuehshan Tunnel

Li, Han-chieh 22 June 2010 (has links)
This study separated two parts: PART ¢¹ Meteorologically adjusted trends of ozone Since meteorological changes strongly affect ambient ozone concentrations, trends in concentrations of ozone upon the adjustment of meteorological variations are important of evaluating emission reduction efforts. This work is to study meteorological effects on the long-term trends of ozone concentration using a multi-variable additive model in Kaohsiung. The long-term trends of ozone concentration were analyzed using the Holland model (without meteorological-adjusted) and the robust MM Regression model (with meteorological-adjusted) based on the data of eight EPA air quality stations from 1997 to 2006 in Kaohsiung area. According to the result of the simulation, the simulated value of the robust MM-Regression model present more valid than the Holland model.The simulated results show that the long-term ozone concentration increases at 13.84% (or 13.06%) monthly (or annually) after meteorological adjustments, less than at 26.10% (or 23.80%) without meteorological adjustments in Kaohsiung county. The simulated results show that the long-term ozone concentration increases at 9.01% (or 6.88%) monthly (or annually) after meteorological adjustments, less than at 22.01% (or 19.67%) without meteorological adjustments in Kaohsiung city. Wind speed, duration of sunshine and pressure are the three dominant factors that influence the ground-level ozone levels in Kaohsiung area. PART ¢º Dispersion of air pollutants in the Hsuehshan Tunnel Concentrations of carbon monoxide (CO) and nitrogen oxides (NOx) were measured from November 14 ¡V 17 2008 in a cross-mountain Hsuehshan traffic tunnel stretching 12.9 km and containing eastward and westward channels. Air pollutants of CO (carbon monoxide) and NOx (nitrogen oxides) will be monitored at the inlet, outlet and vertical shafts of the tunnel. Meanwhile, numerical simulation of three-dimensional turbulent flow will be performed using STAR-CD software. Traffic and pollutant concentrations during the weekends exceeded those during the weekdays. Measured concentrations of CO at the two tunnel outlets (14.5 ¡V 22.8 ppm) were approximately three times higher than those at the two tunnel inlets (3.2 ¡V 7.3 ppm), while concentrations of NOx at the two tunnel outlets (1.9 ¡V 2.9 ppm) were approximately four to five times higher than those at the two tunnel inlets (0.3 ¡V 0.8 ppm). The outlet of vertical draft 2 had the highest pollutant concentrations (CO = 12.3 ppm; NOx = 1.9 ppm), followed by vertical drafts 1 and 3. Three-dimensional turbulence modeling results indicate that airflow in the tunnel was primarily driven by the combined effects of axial fans and vehicles. Results of this study demonstrate that simulated pollutant concentrations increase downstream and are vertically stratified, due to tailpipe exhausts close to tunnel floor. Simulations agreed fairly well with measurements.
98

MESOMÓVEL: UMA ESTAÇÃO METEOROLÓGICA MÓVEL DE SUPERFÍCIE PARA A OBSERVAÇÃO DE FENÔMENOS CONVECTIVOS LOCAIS / MESOMÓVEL: A MOBILE SURFACE WEATHER STATION FOR THE OBSERVATION OF LOCAL CONVECTIVE PHENOMENA

Custodio, Diogo Machado 05 September 2012 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / This study presents a prototype of a deployable unit for automated surface weather observation, named Estação Mesomóvel, which is mounted on a tripod and portable in a small vehicle, allowing its installation in the path of oncoming convective storms. With a high frequency data sampling strategy, the Estação Mesomóvel is capable of monitoring adequately mesoscale surface features produced by convection. The challenges and solutions found during the conception of the prototype are discussed, as well as the results from the data comparison experiments conducted between the Estação Mesomóvel and an automated surface weather station from the operational network. The operation of the Estação Mesomóvel in storm interception mode is presented in the context of the weather analysis and forecasting strategies used, the deployment logistics, and the atmospheric data obtained in the field. Results from the analysis of the collected data showed the capability of the Estação Mesomóvel in sampling the evolution, at high frequency, of convective phenomena at the meso-g scale, such as gust fronts, cold pools, mesohighs and high precipitation rates, which are typically poorly represented by the synoptic-scale surface observing network. This investigation showed the feasibility of conducting storm interception in Brazil with the goal of collecting high-quality atmospheric data for scientific purposes. / Neste trabalho é apresentada a Estação Mesomóvel, que consiste no protótipo de uma unidade tática de observação meteorológica automática de superfície, montada sobre tripé e transportável em um veículo de pequeno porte, podendo assim ser instalada na trajetória de tempestades convectivas. Com sua amostragem em alta frequência, a Estação Mesomóvel é capaz de monitorar de maneira adequada circulações de mesoescala produzidas pela convecção. São apresentados os desafios e as soluções encontradas durante a concepção deste protótipo, e também os resultados de comparações feitas entre as medições da Estação Mesomóvel e de uma estação da rede operacional de observação em superfície. A operação da Estação Mesomóvel em modo de interceptação de tempestades é discutida em termos das estratégias de análise e previsão de tempo empregadas, da logística de deslocamento, e dos dados atmosféricos obtidos em campo. Resultados da análise dos dados coletados pela Estação Mesomóvel mostraram sua capacidade de amostrar a evolução, em alta frequência, de fenômenos convectivos da escala meso-g, como frentes de rajada, piscinas de ar frio, mesoaltas e altas taxas de precipitação, que tipicamente é mal representada pela rede de observação de superfície em escala sinótica. Esta pesquisa demonstrou que é factível realizar no Brasil a coleta de dados meteorológicos com qualidade científica através da estratégia de interceptação de tempestades convectivas.
99

Jak souvisí vlastnosti atmosférických aerosolů s meteorologickými veličinami a koncentracemi plynných polutantů? / What is a connection between atmospheric aerosols, meteorological parameters and gaseous pollutants?

Slezáčková Zíková, Naděžda January 2014 (has links)
Title: What is the connection between atmospheric aerosols, meteorological pa- rameters and gaseous pollutants? Author: RNDr. Naděžda Slezáčková Zíková Department: Department of Meteorology and Environment Protection Supervisor: Ing. Vladimír Ždímal, Dr. Laboratory of Aerosol Chemistry and Physics, Institute of Chemical Process Fun- damentals, Czech Academy of Sciences, v.v.i. Abstract: Five years of atmospheric aerosol (AA) measurements at rural back- ground station Košetice were compared with meteorological records and gaseous pollutants concentrations. The sampling and data analysis of AA data is de- scribed, and the statistical evaluation is done. The variability in the AA con- centrations is significant; the long-term measurements of AA, over the period at least several years, and the differentiation according to the season of the year are thus necessary. The clearly expressed annual cycle of AA concentrations is mainly influenced by two phenomena. From April to September, the total AA concentration cycle is driven mainly by the new particles formation events, from October to March, the concentrations are strongly influenced by particles coming from long-range transport and/or from the regional pollution. The relationship between AA and meteorological parameters, however, is not only season...
100

Automatizace geodetických měření a jejich datová analýza / Automation of Geodetic Measurements and Their Data Analysis

Vojkůvka, Michal January 2018 (has links)
The present thesis deals with the process of automation of geodetic measurements using electronic geodetic instruments, e.g. electronic levels, electronic total stations, as well as other measuring instruments and devices generally used for geodetic measurements, including meteorological sensors. The goal is to design and create a platform for automated measurement system with integrated data collection, their storage and analysis with the help of remote internet access and allowing to export data in various formats.

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