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Ein Bewertungsverfahren für Schallimmissionen unter Einbeziehung des AtmosphärenzustandesViertel, René, Wilsdorf, Michael, Raabe, Armin 04 April 2017 (has links) (PDF)
Es wird ein Verfahren vorgestellt, welches im Rahmen einer Projektbearbeitung für die Bundeswehr entwickelt wurde und die Einbeziehung des meteorologischen Einflusses auf die Schallausbreitung in die Schallimmissionsprognose auf relativ einfache Weise ermöglicht. Zunächst wurden alle denkbaren meteorologischen Situationen (Unterscheidung nach Temperatur, Windgeschwindigkeit und Windrichtung) klassifiziert. Für die verschiedenen Klassen wurden Verteilungen der Schalldruckpegeldämpfung mit dem Schallausbreitungsmodell SMART (Sound Propagation Model for the Atmosphere using Ray Tracing) berechnet. Die Ergebnisse wurden in einer Datenbank zusammengefasst. Die Analyse und Bewertung dieser Prognosen, sowie der Zugriff auf die Datenbank erfolgt über das Visualisierungstool MetaVIS (Meteorological attenuation visualization). Damit ist eine schnelle Schallimmissionsprognose für aktuelle Schallausbreitungssituationen möglich. Im Rahmen dieses Verfahrens ist die Regionalisierung eines Gesamtgebietes in schallklimatologisch ähnliche Teilgebiete möglich. Eine solche Untersuchung erfolgte durch die Analyse von Schalldruckpegeldämpfungskarten für eine Vielzahl von Atmosphärenstrukturen. Im Ergebnis konnte eine Karte zur Neustrukturierung der Beratungsräume der Bundeswehr, unter Berücksichtigung meteorologischer Einflüsse auf die Schallausbreitung, erarbeitet werden. / A procedure is described, which has been developed within the framework of a project for the Bundeswehr. This method provides a relatively simple way to include meteorological influences on the sound propagation for forecasting sound immission. Therefore, at first, different meteorological situations (differentiation regarding temperature, wind speed, wind direction) have been classified. For the different classes the spatial distribution attenuation of sound level have been calculated using a model of sound propagation SMART (Sound propagation model of the atmosphere using ray-tracing). The results are stored in a database. The analysis and evaluation of this forecasts as well as the access to the database is realized using the visualization tool MetaVIS (Meteorological attenuation visualization). Therewith fast forecasts of sound immission for present
meteorological situations are enabled. Moreover, with this procedure a regionalization of an entire territory in areas with a similar sound climatology is possible. Such an estimation has been done by analysing maps of sound level attenuation for different atmospheric structures. As a result, a map for restructuring the consulting areas of the Bundeswehr, considering meteorological influences on the sound propagation, could be acquired.
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Remote sensing of swell and currents in coastal zone by HF radar / Télédétection de la houle océanique et d'autres processus côtiers via un radar HFWang, Weili 27 May 2015 (has links)
L’environnement maritime du littoral implique de nombreux processus complexes, mais le manque de données en haute résolution couvrant une large zone sur une longue période est souvent l’obstacle principal à des recherches plus approfondies. Le radar haute-fréquence (HF) est un moyen de faire de la télédétection afin d’obtenir pratiquement en temps réel de l’information sur la surface de la mer et sur une large zone. Ainsi l’étude de l’inversion des paramètres marins à partir de données issues de radars HF est réellement porteuse de sens. Cette thèse fait l’usage d’un jeu de données collectées durant 13 mois par deux réseaux de radar HF à commande de phase pour étudier les caractéristiques de signaux d’échos de la mer, étudier les données à traiter et les méthodes d’inversion, calculer les paramètres de la surface de la mer et évaluer la précision de l’inversion radar des paramètres de la houle.Cette thèse se réfère à l’onde de sol radar HF, dont les ondes radio interagissent avec l’océan du fait de la diffraction de résonance de Bragg. Nous passons en revue l’historique et les applications du radar HF. Nous rappelons les bases de la théorie des ondes électromagnétiques. Nous décrivons les principes d’inversion des courants de surface de la mer, direction du vent et paramètres de houles. La faisabilité de l’inversion de paramètres de houle est examinée. A partir de l’analyse théorique et des études statistiques de nombreux échantillons de données, cette thèse propose une série de méthodes sur le traitement du signal brut et le contrôle de qualité, ce qui inclut la détermination du niveau de bruit, le moyennage des données dans l’espace et le temps, l’identification correcte des pics spectraux, le seuil de largeur de pic, etc. Respectant les caractéristiques de différents processus physiques, les inversions de courant et de vent utilisent des spectres collectés toutes les 20 minutes ; l’inversion des paramètres de houle utilise des spectres moyennés sur 1 heure. Les statistiques des spectres utilisés pour le calcul des paramètres de houle sont présentées pour chacune des stations. Un ensemble de programme efficaces de calculs automatiques avec une complexité algorithme réduite sont développés pour réaliser le traitement et en tirer les paramètres marins.Les vitesses de courants radiales sont obtenues à partir d’une unique station radar. Les champs de vecteurs de courants sont obtenus en combinant chaque station. On montre une année de débit moyen dans la mer d’Iroise, ainsi que le calcul de la vorticité et de la divergence. On étudie un ensemble de données d’un mois du radar SeaSonde de Qingdao. Les schémas de débit moyen, ainsi que la vorticité et la divergence sur un mois sont présentés.La direction relative du vent par rapport à la direction de visée du radar est mesurée à travers le ratio des amplitudes des pics de Bragg. Différents modèles empiriques sont employés pour obtenir la vitesse relative du vent par inversion radar. Les résultats présentés sont en accord avec les estimations prédites par le modèle. Différents modèles de distribution directionnelle sont utilisés pour mesurer le facteur de diffusion pour la mer d’Iroise.Cette thèse se concentre sur l’étude des paramètres de houle. Les résultats sont validés à l’aide de bouées et de données du modèle de vagues (Wavewatch III). L’estimation montre que la précision de la fréquence de houle est très bonne, la précision sur la hauteur significative de houle est très raisonnable et la précision sur la direction absolue de la houle est faible. La cohérence des mesures par chacune des stations radars est vérifiée par comparaison entre les deux. L’utilisation conjointe des échantillons est également prise en charge pour réaliser l’inversion. L’utilisation de deux radars n’améliore pas seulement la précision, mais résout aussi l’ambiguïté de direction relative de houle à partir d’une unique station et donne la direction absolue de vague avec une certaine précision. / Nearshore marine environment contains many complex processes, but the lack of high-resolution data over a large area during a long time is often the primary obstacle to further research. High-frequency (HF) radar is a mean of remote sensing which obtains continuous near-real time sea surface information over a large area. Thus the study of inversion of marine parameters from HF radar data is very meaningful. Thisthesis makes use of a 13-month-long dataset collected by two phased array HF radar to investigate the characteristics of the sea echo signals, study the data processing and inversion methods, compute sea surface parameters and evaluate the accuracy of radarinversion of swell parameters.The thesis refers to the ground wave HF radar, whose radio waves interact with ocean by Bragg resonance scattering. The development history and applications of HF radar is introduced. The basic theory of electromagnetic wave is reviewed. The principles of inversion of sea surface current, wind direction and swell parameters are described. The feasibility of the swell parameter inversion is investigated. Based on theoretical analysis and statistical studies of a large number of samples, the thesis proposes a series of methods on raw signal processing and quality control, including the determination of the noise level, data averaging in space and time, the proper identification of spectral peaks, the peak width threshold, etc. Respecting the characteristics of different physical processes, inversions of current and wind use spectra collected every 20 min; inversion of swell parameters uses one-hour averaged spectra. The statistics of qualified spectra for swell parameter calculations are presented for both stations. A set of efficient, with a reduced computational cost, automatic computing programs are developed to do the processing and derive marine parameters. Radial current velocities are derived from single radar station. Current vector fields are obtained by combination of both stations. One-year mean flow field in the Iroise Sea is shown, together with the computation of vorticity and divergence. A one-month SeaSonde radar dataset off Qingdao is studied. One-month mean flow pattern together with vorticity and divergence are presented.Relative wind direction with respect to radar look direction is measured through ratio of Bragg peaks amplitudes. Different empirical models are employed to derive radar-inverted relative wind direction. Results show reasonable agreement with model estimations. Different directional distribution models are used to measure the spreading factor for the Iroise Sea. The thesis focuses on the study of swell parameters. Results are validated by buoy and wave model (WAVEWATCH III) data. The assessments show that the accuracy of swell frequency is very good, the accuracy of swell significant waveheight is reasonable, and the accuracy of relative swell direction is low.Consistency of measurements by both radar stations is verified by comparison between the two. This also supports the use of double samples to do the inversion. Use of two radars not only further improves the accuracy but also solves the ambiguity of relative swell direction from single station and gives the absolute wave direction to a certain precision. The thesis proposes a constant relative directionmethod to derive swell significant waveheight, based on the studies of radar integral equation and the inverted results of relative swell direction. This proposal is demonstrated to improve the agreement of radar inversion and buoy/model provided significant waveheight and increases significantly the number of samples. The thesis investigates the accuracy of swell parameters obtained by HF radar. Contributions of random errors in radar observations are quantified. Comparing the differences between radar and buoy/model estimations gives assessments of the contribution of radar intrinsic uncertainty and contribution of other factors.
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Model Sensitivity, Performance and Evaluation Techniques for The Air Pollution Model in Southeast QueenslandLeishman, Natalie January 2005 (has links)
One important component for successful air quality modelling is the utilisation of a reliable meteorological simulator. Evaluating the model with respect to its overall performance in predicting natural processes is no easy task. The problem is twofold, firstly there is the availability and suitability of field data with which to compare a model with and secondly there is the method of evaluation. The Air Pollution Model (TAPM), developed by the CSIRO was used to simulate the winds in Southeast Queensland (SEQ). The complex nature of the airshed makes it difficult to compare modelled data with observational data as the observational data may be influenced by local phenomena. Evaluation of the model through the use of standard statistics and monthly and seasonal statistics illustrated that overall the model predicted the annual average wind speeds and temperatures well. Through the use of synoptic clustering, more detail on model performance was gained and it was found that TAPM predicted sea breezes that occurred on high pollution days. The sensitivity of the model to the selection of input parameters such as soil type, land use, vegetation, and rain processes was also investigated.
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Dispersão de machos de Diatraea saccharalis (Fabricius) (Leipdoptera: Crambidae) em cana-de-açúcar /Caixeta, Daniel Ferreira. January 2010 (has links)
Orientador: Odair Aparecido Fernandes / Banca: José Alexandre Freitas Barrigossi / Banca: Leila Lucci Dinardo-Miranda / Resumo: A broca-da-cana, Diatraea saccharalis (Fabr.), é a uma das pragas mais importantes da cana-de-açúcar no Brasil. Para o sucesso na utilização de plantas geneticamente modificadas visando o controle deste inseto, faz-se necessário conhecer sua dispersão. Estudos da dinâmica de vôo também podem ajudar na compreensão do comportamento do inseto, e de suas interações ecológicas. O estudo da dispersão de D. saccharalis foi possível através da marcação, liberação e captura dos machos adultos. A marcação foi realizada por meio da incorporação de corante lipossolúvel à dieta das larvas. As armadilhas de feromônio foram dispostas nos talhões de cana-de-açúcar nos sentidos norte, sul, leste e oeste, circundando o ponto de liberação. Os resultados obtidos mostram que mais de 45 % dos machos marcados capturados permaneceram nas áreas mais próximas ao ponto de liberação. Fatores climáticos como a temperatura, umidade relativa, velocidade do vento e precipitação não interferem decisivamente na captura dos machos liberados e dos machos do campo. A direção do vento exerce um papel fundamental na dispersão de D. saccharalis, uma vez que a maioria dos insetos voou a favor do vento. O modelo mais adequado para explicar a relação entre a distância de vôo e o número de indivíduos capturados é dado por y = a2/(1+(2a1,8bx))2,6. Com isso, para o manejo de resistência de D. saccharalis em cultivos de cana-de-açúcar geneticamente modificada expressando proteínas de Bacillus thuringiensis Berliner, deve se manter no máximo 800 m de distância entre as áreas de refúgio / Abstract: The sugarcane borer, Diatraea saccharalis (Fabr.), is one of the most important sugarcane pests in Brazil. For a successful utilization of genetically modified crops aiming at the control of this insect, it is necessary to know its dispersal. Studies of flight dynamics can also help understand the insect's behavior and its ecological interactions. The study of D. saccharalis dispersal was possible through labeling, releasing and capturing adult males. Labeling was performed by incorporating oil soluble dyes into the larval diet. The pheromone traps were placed in a sugarcane field following the cardinal directions (North, South, East, West) around the release site. The results showed that more than 45 % of the labeled males were captured closer to the release site. Climatic factors such as temperature, relative humidity, wind speed and rain do not affect decisively in the release or wild males capture. The wind direction is important in D. saccharalis dispersal, once the majority of insects flew towards the wind. The most adequate model to explain the relationship between flight distance and number of captured insects is y = a2/(1+(2a1,8bx))2,6. Thus, for resistance management of D. saccharalis in genetically modified sugarcane expressing Bacillus thuringiensis Berliner proteins, the refugia sites should be kept at most 800 m apart / Mestre
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Dispersão de machos de Diatraea saccharalis (Fabricius) (Leipdoptera: Crambidae) em cana-de-açúcarCaixeta, Daniel Ferreira [UNESP] 22 February 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:25:19Z (GMT). No. of bitstreams: 0
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caixeta_df_me_jabo.pdf: 1848611 bytes, checksum: 79743f9ce966451f4711dc33bf6a1398 (MD5) / A broca-da-cana, Diatraea saccharalis (Fabr.), é a uma das pragas mais importantes da cana-de-açúcar no Brasil. Para o sucesso na utilização de plantas geneticamente modificadas visando o controle deste inseto, faz-se necessário conhecer sua dispersão. Estudos da dinâmica de vôo também podem ajudar na compreensão do comportamento do inseto, e de suas interações ecológicas. O estudo da dispersão de D. saccharalis foi possível através da marcação, liberação e captura dos machos adultos. A marcação foi realizada por meio da incorporação de corante lipossolúvel à dieta das larvas. As armadilhas de feromônio foram dispostas nos talhões de cana-de-açúcar nos sentidos norte, sul, leste e oeste, circundando o ponto de liberação. Os resultados obtidos mostram que mais de 45 % dos machos marcados capturados permaneceram nas áreas mais próximas ao ponto de liberação. Fatores climáticos como a temperatura, umidade relativa, velocidade do vento e precipitação não interferem decisivamente na captura dos machos liberados e dos machos do campo. A direção do vento exerce um papel fundamental na dispersão de D. saccharalis, uma vez que a maioria dos insetos voou a favor do vento. O modelo mais adequado para explicar a relação entre a distância de vôo e o número de indivíduos capturados é dado por y = a2/(1+(2a1,8bx))2,6. Com isso, para o manejo de resistência de D. saccharalis em cultivos de cana-de-açúcar geneticamente modificada expressando proteínas de Bacillus thuringiensis Berliner, deve se manter no máximo 800 m de distância entre as áreas de refúgio / The sugarcane borer, Diatraea saccharalis (Fabr.), is one of the most important sugarcane pests in Brazil. For a successful utilization of genetically modified crops aiming at the control of this insect, it is necessary to know its dispersal. Studies of flight dynamics can also help understand the insect’s behavior and its ecological interactions. The study of D. saccharalis dispersal was possible through labeling, releasing and capturing adult males. Labeling was performed by incorporating oil soluble dyes into the larval diet. The pheromone traps were placed in a sugarcane field following the cardinal directions (North, South, East, West) around the release site. The results showed that more than 45 % of the labeled males were captured closer to the release site. Climatic factors such as temperature, relative humidity, wind speed and rain do not affect decisively in the release or wild males capture. The wind direction is important in D. saccharalis dispersal, once the majority of insects flew towards the wind. The most adequate model to explain the relationship between flight distance and number of captured insects is y = a2/(1+(2a1,8bx))2,6. Thus, for resistance management of D. saccharalis in genetically modified sugarcane expressing Bacillus thuringiensis Berliner proteins, the refugia sites should be kept at most 800 m apart
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Land/ Sea Breeze Circulation Systems of Churchill, ManitobaHolland, Susan 04 1900 (has links)
This research paper was submitted to the Department of Geography in fulfilment of the requirements of Geography 4C6. / This research details the presence of the land/ sea breeze circulation system near Churchill, Manitoba. Data collected from June 6 to August 13, 1987 were analyzed with respect to wind direction, temperature and vapour pressure to determine the effects of the system on the climate. Results indicate that there is a seasonal progression in wind frequency from dominantly onshore (42% of the time) to dominantly mixed winds (75% of the time). The frequency of the land/ sea breeze increases across the season. Smaller wind velocities, colder temperatures and larger vapour pressures are associated with onshore winds, while offshore winds have greater velocities, higher temperatures, and smaller vapour pressures. Offshore winds are 5-7°C warmer than onshore winds. The sea breeze is larger than the land breeze by a 3:2 ratio. / Thesis / Bachelor of Arts (BA)
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Ein Bewertungsverfahren für Schallimmissionen unter Einbeziehung des AtmosphärenzustandesViertel, René, Wilsdorf, Michael, Raabe, Armin 04 April 2017 (has links)
Es wird ein Verfahren vorgestellt, welches im Rahmen einer Projektbearbeitung für die Bundeswehr entwickelt wurde und die Einbeziehung des meteorologischen Einflusses auf die Schallausbreitung in die Schallimmissionsprognose auf relativ einfache Weise ermöglicht. Zunächst wurden alle denkbaren meteorologischen Situationen (Unterscheidung nach Temperatur, Windgeschwindigkeit und Windrichtung) klassifiziert. Für die verschiedenen Klassen wurden Verteilungen der Schalldruckpegeldämpfung mit dem Schallausbreitungsmodell SMART (Sound Propagation Model for the Atmosphere using Ray Tracing) berechnet. Die Ergebnisse wurden in einer Datenbank zusammengefasst. Die Analyse und Bewertung dieser Prognosen, sowie der Zugriff auf die Datenbank erfolgt über das Visualisierungstool MetaVIS (Meteorological attenuation visualization). Damit ist eine schnelle Schallimmissionsprognose für aktuelle Schallausbreitungssituationen möglich. Im Rahmen dieses Verfahrens ist die Regionalisierung eines Gesamtgebietes in schallklimatologisch ähnliche Teilgebiete möglich. Eine solche Untersuchung erfolgte durch die Analyse von Schalldruckpegeldämpfungskarten für eine Vielzahl von Atmosphärenstrukturen. Im Ergebnis konnte eine Karte zur Neustrukturierung der Beratungsräume der Bundeswehr, unter Berücksichtigung meteorologischer Einflüsse auf die Schallausbreitung, erarbeitet werden. / A procedure is described, which has been developed within the framework of a project for the Bundeswehr. This method provides a relatively simple way to include meteorological influences on the sound propagation for forecasting sound immission. Therefore, at first, different meteorological situations (differentiation regarding temperature, wind speed, wind direction) have been classified. For the different classes the spatial distribution attenuation of sound level have been calculated using a model of sound propagation SMART (Sound propagation model of the atmosphere using ray-tracing). The results are stored in a database. The analysis and evaluation of this forecasts as well as the access to the database is realized using the visualization tool MetaVIS (Meteorological attenuation visualization). Therewith fast forecasts of sound immission for present
meteorological situations are enabled. Moreover, with this procedure a regionalization of an entire territory in areas with a similar sound climatology is possible. Such an estimation has been done by analysing maps of sound level attenuation for different atmospheric structures. As a result, a map for restructuring the consulting areas of the Bundeswehr, considering meteorological influences on the sound propagation, could be acquired.
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Uppskattning av vindklimat – Implementering och utvärdering av en metod för normalårskorrektionHelmersson, Irene January 2010 (has links)
The expected technical lifetime for a wind turbine is 20-25 years (Wizelius, 2007). In the process of planning a wind farm on a site an estimation of the average wind speed and the energy yield is required from the site. Due to large fluctuations in wind velocity from one year to another it is, from a climatologically point of view, not sufficient to measure the wind for a short period of time, e.g. one year. The year measured may have uncommonly high or uncommonly low winds and thereby generate an average not representative of the wind climate on the site. In the same time it is neither practical nor economically desirable to measure for a longer time period. Instead the measured data collected for a short period of time is scaled into a normal year before it is used to calculate the energy content. This normal year correction can be preformed using different methods. Principally, the methods relate the short time series, measured on the site, to one or more variables of a long time reference series. As a long time reference series the geostrophic wind on the site or a series of measured wind nearby can be used. If the correlation between the two series is sufficiently high a normal year correction may be done using the relation. Normal year correction has foremost been done using the relation between the velocities of the measured wind and a reference wind. The purpose in this study is to evaluate and implement a part of an algorithm for normal year correction considering additional variables besides wind velocity. The relationships studied are between measured wind speed and geostrophic wind speed, geostrophic wind direction and time of the year. For the purpose of evaluating the algorithm two wind data series from Näsudden, on the Swedish island of Gotland, for a period of 15 years has been used. Measured wind on 75 meters and geostrophic wind on 850hPa. Where the geostrophic wind has been used as a long time reference and the measured wind for one year at the time has been related to this reference. The relation has then been used together with the geostrophic wind data to create an estimation of the wind climate on Näsudden in three steps. Step one establishes the estimation due to the relation of geostrophic wind speed. Step two corrects the estimation due to the relation of geostrophic wind direction and step three corrects the estimation due to the relation of time of year. The conclusions from this study showed that with the method used for implementing the algorithm the normal year correction using only the relation between the velocities of the measured wind and the geostrophic wind gives the best estimation of the climatically mean wind speed. The standard deviation gives a 5 % risk for more than 0.436 m/s error for estimation of the mean wind on the site, which is comparable to earlier studies. The introduction of the wind direction dependence overestimates the mean wind on the site and amplifies the error. The introduction of the season dependence amplifies the error further and overestimates the mean wind additionally. / En vindturbin har en planerad livslängd på 20-25 år (Wizelius, 2007). Vid planering av en vindkraftspark behöver en estimering av medelvinden och energiutvinningen utföras för platsen man är intresserad av. På grund av stora fluktuationer av vindhastighet från år till år är det ur klimatologisk synpunkt inte tillräckligt att mäta under en kort period, exempelvis ett år. Det år man mäter kan ha ovanligt starka eller ovanligt svaga vindar och ge en icke representativ bild av vindklimatet på platsen. Samtidigt är det inte praktiskt eller ekonomiskt önskvärt att mäta under en längre tidsperiod. Istället kan den korta mätserie som insamlats korrigeras till ett normalår med hjälp av en långtidsreferens innan den används för att beräkna energiinnehållet. I princip går normalårskorrigering ut på att relatera den korta mätserien till en eller flera variabler i långtidsreferensen. Som långtidsreferensdata kan den geostrofiska vinden på platsen eller en lång mätserie från en närliggande plats användas. Om korrelationen mellan de två serierna är tillräckligt hög kan en normalårskorrigering göras med hjälp av relationen. Tidigare har man vid normalårskorrigering främst sett till relationen mellan vindhastigheterna för den uppmätta vinden och en referensvind. Syftet i detta arbete är att utvärdera en del av en algoritm för normalårskorrigering där hänsyn tas till fler variabler än endast vindhastighet. Samband som studeras är mellan uppmätt vindhastighet och geostrofisk vindhastighet, geostrofisk vindriktning och tid på året. För utvärderingen av algoritmen har två vinddataserier från Näsudden på Gotland använts för en period av 15 år med uppmätt vind på 75m och geostrofisk vind på 850hPa. Där den geostrofiska vinden fått representera långtidsreferensen och den uppmätta vinden för ett år i taget har relaterats till denna. Efter normalårskorrigeringen har den uppmätta vinden för 15 år fått representera vindklimatet på platsen som jämförelse. Enligt algoritmen har uppskattning av vindklimatet på Näsudden skapats i tre steg. Steg 1 är en uppskattning av vinden från sambandet för geostrofisk vindhastighet. Steg 2 är en korrektion av uppskattningen genom sambandet till geostrofisk vindriktning och steg 3 en korrektion av uppskattningen genom sambandet till tid på året. Efter vart steg skickas det aktuella estimatet vidare till nästa steg där det korrigeras med avseende på nästa samband. Slutsatserna från undersökningen visade att med den metod som använts ger normalårskorrigeringen med enbart sambandet till hastighet bäst uppskattning av den klimatologiska medelvinden. Standardavvikelsen för estimatet ger 5 % risk för mer än 0,436 m/s fel vid uppskattning av klimatologisk medelvind vilket är jämförbart med tidigare studier. Vidare överskattar införandet av vindriktningsberoendet den uppskattade medelvindhastigheten samt ökar osäkerheten. Även införandet av säsongsberoendet överskattar medelvindhastigheten ytterligare samt även osäkerheten.
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Quantification of the Seasonality and Vertical Dispersion Environment of PM2.5 Variation: A Comparative Analysis of Micro-Scale Wind-Based Buffer MethodsRay, Noah R. 05 1900 (has links)
Increasing PM2.5 (particulate matter smaller than 2.5 micrometers) poses a significant health risk to people. Understanding variables critical to PM2.5 spatial and temporal variation is a first step towards protecting vulnerable populations from exposure. Previous studies investigate variables responsible for PM2.5 variation but have a limited temporal span. Moreover, although land-use classes are often taken into account, the vertical environment's influence (e.g., buildings, trees) on PM2.5 concentrations is often ignored and on-road circle buffers are used. To understand variables most critical to PM2.5 concentration variation, an air pollution sensor and GPS unit were affixed to a bicycle to sample for variables over three seasons (spring, summer, fall). Samples were taken on a route during the weekdays at four targeted hours (7AM, 11AM, 3PM, and 7PM) and joined with meteorological data. 3D morphology was assessed using LiDAR data and novel wind-based buffers. Wind speed only, wind direction only, and wind speed and direction buffers were computed and compared for their performance at capturing micro-scale urban morphological variables. Zonal statistics were used to compute morphological indicators under different wind assumptions in seasonal ordinary least squares regression models. A comprehensive wind and buffer performance analysis compares statistical significance for spatial and temporal variation of PM2.5. This study identifies the best wind parameters to use for wind-based buffer generation of urban morphology, which is expected to have implications for buffer design in future studies. Additionally, significant exposure hotspots for UNT students to PM2.5 pollution are identified.
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Integrated, Intelligent Sensor Fabrication Strategies for Environmental MonitoringSuzuki, Takeharu, n/a January 2004 (has links)
The humidity, temperature, wind speed/direction micro sensors can be manufactured individually, resulting in three individual substrates. The integration of the three sensors into a single substrate is a vital challenge to achieve an integrated intelligent sensor so called a multiple sensor. This requires the integration of process flows and is a major challenge because adequate sensor performance must be maintained. Polyimide was selected as a humidity sensing material for its compatibility with conventional integrated circuit fabrication technology, negligible temperature dependence and good resistance against contamination. Nickel was selected for the temperature and wind speed/direction sensor because of its useful temperature coefficient and the advantage of its cost. Since the known wet etchant for nickel requires hard-baked photoresist, a method which does not attack the polyimide while removing the photoresist must be developed. The method developed for etching nickel employs hard-bake-free photoresist. Other challenge was ensuring good thermal isolation for the wind speed/direction sensor fabricated on a silicon nitride layer preformed on top of a silicon wafer. Since silicon acts as a good heat sink, the silicon under the sensor was etched entirely away until the silicon nitride layer was reached. This structure achieved good thermal isolation resulting in small power consumption. This low power feature is essential for sensors deployed in fields where power access or replacement of power sources is restricted. This structure was compared with the structure created by polyimide plateau on a silicon nitride layer coated on a silicon substrate as a function of power consumption. Based on the examination of thermal isolation, the multiple sensor utilizing a MEMS technique was fabricated with a single-sided mask aligner. The characteristics of humidity sensors fabricated with polyimide were examined in detail with respect to variations of electrode structures, improvement of sensitivity, effect of process temperature, temperature and frequency dependence, and stability. The humidity sensor constructed with O2 plasma treated polyimide resulted an improvement in sensitivity and hysteresis. The investigation using XPS, FTIR and AFM concluded the chemical modification of polyimide played an important role in this improvement. The design, fabrication and results of a series of humidity sensors are quantified. There is always no unique packaging solution for sensors because of the application-specific nature of the sensors. This intelligent environmental monitoring system was designed to accommodate both an environmental sensor and its signal conditioning electronics circuitry (SICONEC) into a single package. The environmental sensors need direct exposure to the environment while SICONEC needs a sealed encapsulation to avoid environmental damage. A new style of packaging addressing these requirements was demonstrated using a hot embossing machine. The hot embossing machine was used to embed an integrated circuit (IC) in a bare die condition into a polycarbonate (PC) sheet. In this case, the IC was flipped down against the PC, which protects the front side of the IC from the environmental damages. In a test phase, a die containing operational amplifiers was embossed into the PC. A humidity sensor and surface mount resisters were placed on the same surface of the PC to test the validity of this new technique. Interconnection between the embossed die and the humidity sensor was established using bonding wires. Copper tracks were also used to ensure all electrical connections for the die, the humidity sensor and the resistors. The results clarified the method developed. Details of process methods, issues and further potential improvement are reported.
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