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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.
11

Συμβολή των Συστημάτων Γεωγραφικών Πληροφοριών (GIS) και της περιβαλλοντικής εκπαίδευσης στην διαχείριση φυσικών περιοχών

Καλησπέρη, Αγγελική 10 June 2014 (has links)
Τα GIS αποτελούν σημαντικά εργαλεία στη διαχείριση των φυσικών περιοχών καθώς έχουν την δυνατότητα καταγραφής, ανάλυσης, παρουσίασης χωρικών και άλλων δεδομένων. Επίσης, η Περιβαλλοντική Εκπαίδευση αποτελεί μια σημαντική πρόταση για την επίτευξη σωστής διαχείρισης των φυσικών περιοχών και μπορεί να συμβάλει στην προστασία του περιβάλλοντος. Καθώς η Περιβαλλοντική Εκπαίδευση είναι άρρηκτα συνδεδεμένη με παράγοντες που αφορούν το περιβάλλον, τα GIS μπορούν να αποτελέσουν ένα εργαλείο για την επίτευξη των στόχων της. Η συλλογή δεδομένων από φορείς που εφαρμόζουν προγράμματα μη τυπικής Περιβαλλοντικής Εκπαίδευσης (Φορείς Διαχείρισης και Κέντρα Περιβαλλοντικής Εκπαίδευσης), ως προς τα προγράμματα και το εκπαιδευτικό υλικό που χρησιμοποιούν, οδήγησε στη δημιουργία θεματικών χαρτών με την βοήθεια των GIS. Οι θεματικοί χάρτες μπορούν να επεκταθούν και με άλλα θεματικά πεδία, ανά διαστήματα δε να ενημερώνονται και να επικαιροποιούνται. Επιπλέον, μπορούν να προστεθούν και στοιχεία που αφορούν τις ΜΚΟ. Ως περιοχή εστιασμένης έρευνας επιλέχθηκε ο ποταμός Χάραδρος ( μέσος και κάτω ρους) που βρίσκεται στην ευρύτερη περιοχή των Πατρών. Ο Χάραδρος διατηρεί ακόμα μέρος της φυσικότητάς του με χαρακτηριστική παρόχθια βλάστηση κατά τόπους, παρά τις έντονες πιέσεις και τροποποιήσεις που δέχεται. Σημαντική είναι επίσης η παρουσία του πλατανοδάσους κοντά στις εκβολές, με το μοναδικό εξελισσόμενο Δέλτα στη βόρεια Πελοπόννησο. Την μελέτη της περιοχής και τον προσδιορισμό των κύριων μονάδων βλάστησης και των ανθρωπογενών επιδράσεων στην περιοχή ακολούθησε η δημιουργία θεματικών χαρτών με την βοήθεια των GIS, για την εξαγωγή συμπερασμάτων ως προς την οικολογική κατάσταση του ποταμού. Τέλος δημιουργήθηκε ένα πρόγραμμα Περιβαλλοντικής Εκπαίδευσης για τον ποταμό Χάραδρο όπου τα GIS χρησιμοποιούνται ως εργαλείο, με βασικό στόχο την ευαισθητοποίηση της τοπικής κοινωνίας και την απόκτηση ενεργού στάσης και τάσης για συμμετοχή σε δράσεις που αφορούν την προστασία του. Το πρόγραμμα συνοδεύεται από ένα πλήρες πρωτότυπο εκπαιδευτικό υλικό (φύλλα εργασίας, χάρτες, ενημερωτικό υλικό για τα ποτάμια οικοσυστήματα και τον Χάραδρο, κλείδες) που αποτελεί προϊόν της μελέτης στην περιοχή. Τόσο η Περιβαλλοντική Εκπαίδευση όσο και τα GIS, μεμονωμένα ή σε συνδυασμό, μπορούν να αποτελέσουν χρήσιμα εργαλεία για την διαχείριση των φυσικών περιοχών. / GIS are important tools in the management of natural areas as they have the ability to record, analyse and present spatial and other type of data. Environmental Education is an important proposal in order to achieve the right management of natural areas and can be helpful in the protection of the environment. As Environmental Education is strongly connected to factors that concern the environment, GIS may be used as a tool to achieve its objectives. We collected data from organizations applying programmes of non-formal environmental education (Management Agencies for protected areas and Centres for Environmental Education), about the programmes and educational materials that they use and we have created thematic maps by using GIS. These maps may be extended to other thematic fields, informed and updated at certain intervals. Moreover, data related to NGOs may can be added later on. The chosen case study area is the river Charadros (middle and lower river course), located in the broader area of the city of Patras. Despite the intense pressure and modifications that it sustains, Charadros still maintains part of its naturalness with typical riparian vegetation in some places. The presence of the plane forest near the river’s estuaries with its unique evolving Delta in northern Peloponnese is also an important reason to choose this as our study area. Our study included identification of the main vegetation units and the man induced impacts on them, was followed by the creation of thematic maps with the use of GIS, in order to assess the ecological status of the river. Finally, we have created an Environmental Education program for the river Charadros, where GIS are used as a tool. The principal aim of the program is to raise the awareness of the local community and help it to adopt an active participate in actions concerning the protection of the area. This programme also includes a complete and original educational material (worksheets, maps, information material for river ecosystems and Charadros speciffically, and photos serving as keys to identify plant species). Environmental Education and GIS, individually or in combination, can be useful as tools for the management of natural areas.
12

Η χρήση του GIS στη μελέτη της διάβρωσης σε γεωλογικά ενεργές λεκάνες απορροής του Κορινθιακού κόλπου

Τσουνάκα, Σταυρούλα 09 October 2009 (has links)
Ο σκοπός της εργασίας είναι η ανάλυση της χωρικής κατανομής των κατολισθητικών φαινομένων στην υδρολογική λεκάνη του Βουραϊκού ποταμού. Απώτερος σκοπός είναι η δημιουργία ενός χάρτη ευστάθειας πρανών (χάρτης επικινδυνότητας) ο οποίος θα μπορεί να παρέχει σημαντικές πληροφορίες για περιοχές επιδεκτικές σε κατολίσθηση. / -
13

ENHANCED GRAIN CROP YIELD MONITOR ACCURACY THROUGH SENSOR FUSION AND POST-PROCESSING ALGORITHMS

Veal, Matthew Wayne 01 January 2006 (has links)
Yield monitors have become an indispensable part of precision agriculture systemsbecause of their ability to measure the yield variability. Accurate yield monitor data availabilityis essential for the assessment of farm practices. The current technology of measuring grainyields is prone to errors that can be attributed to mass flow variations caused by the mechanismswithin a grain combine. Because of throughput variations, there are doubts regarding thecorrelation between the mass flow measurement and the actual grain volume produced at aspecific location. Another inaccuracy observed in yield monitor data can be attributed to inexactcut-widths values entered by the machine operator.To effectively address these yield monitor errors, two crop mass flow sensing deviceswere developed and used to correct yield monitor data. The two quantities associated with cropmaterial mass flow that were sensed were tension on the feeder housing drive chain and thehydraulic pressure on the threshing cylinder's variable speed drive. Both sensing approacheswere capable of detecting zero mass flow conditions better than the traditional grain mass flowsensor. The alternative sensors also operate without being adversely affected by materialtransport delays. The feeder housing-based sensor was more sensitive to variations in cropmaterial throughput than the hydraulic pressure sensor. Crop mass flow is not a surrogate forgrain mass flow because of a weak relationship (R2 andlt; 0.60) between the two quantities. The cropmass flow signal does denote the location and magnitude of material throughput variations intothe combine. This delineation was used to redistribute grain mass flow by aligning grain andcrop mass flow transitions using sensor fusion techniques. Significant improvements (?? = 0.05)in yield distribution profile were found after the correction was applied.To address the cut-width entry error, a GIS-based post-processing algorithm wasdeveloped to calculate the true harvest area for each yield monitor data point. Based on theresults of this method, a combine operator can introduce yield calculation errors of 15%. Whenthese two correction methods applied to yield monitor data, the result is yield maps withdramatically improved yield estimates and enhanced spatial accuracy.
14

Implementing The Dijsktra

Hakbilir, Muzaffer 01 May 2004 (has links) (PDF)
Network analysis in GIS is often related to finding solutions to transportation problems. In a GIS the real world is represented by either one of two spatial models, vector-based, or raster-based. Prefering raster or vector GIS is more a question of choice than of accuracy. A raster-based GIS model shows a better fit, when the problem is concerned with finding a path across terrain which does not have predefined paths. The approach of this study is to translate the scenario into a &lsquo / least-cost path&rsquo / graph with an associated cost function on the raster-based GIS layer. Sometimes, computation of shortest paths between different locations on a raster-based GIS has to be done in real-time. Therefore, knowing which shortest path algorithm runs fastest on real networks is needed. In order to meet this requirement, Dijsktra&rsquo / s algorithm with priority queue implementation is selected, because it reduces the time complexity of Dijsktra&rsquo / s algorithm from O(V2 log V) to O(E log V ). The run-time results of Dijsktra&rsquo / s algorithm, Dijsktra&rsquo / s algorithm with priority queue implementation and ArcMap Spatial Analyst Tool are compared for a number of raster GIS layers which have different number of nodes. Dijsktra&rsquo / s algorithm with priority queue implementation and Spatial Analyst tool of ArcMap show a linear relationship between node numbers and time, whereas Dijsktra&rsquo / s algorithm represents a quadratic relationship. Hence, when the number of nodes and edges in graph is increased, the run-time performance of the Dijsktra&rsquo / s algorithm decreases rapidly.
15

Gis-based Structural Performance Assessment Of Sakarya City After 1999 Kocaeli-turkey Earthquake From Geotechnical And Earthquake Engineering Point Of View

Yilmaz, Zeynep 01 July 2004 (has links) (PDF)
The August 17, 1999 Kocaeli-Turkey Earthquake (Mw=7.4) caused severe damage to the structures and lifelines in the Marmara region. Soil liquefaction was identified as one of the major causes of this damage. The aim of this study is to determine geotechnical and earthquake engineering factors that contribute to the structural damage observed in Sakarya city after 1999 Kocaeli Earthquake. For this purpose, the results of an extensive field investigation program compiled by General Directorate of Disaster Affairs including subsurface soil characterization and documenting structural performance data were used. The database was carefully screened for poor quality data and was transferred to geographic information system (GIS) framework. Maximum likelihood methodology for the probabilistic assessment of seismically induced structural performance was chosen as the statistical tool. After series of sensitivity analyses, important geotechnical and earthquake engineering parameters of the problem were selected as i) liquefaction severity index, ii) post liquefaction volumetric settlement, iii) peak ground acceleration and, iv) spectral acceleration defined at the period range of conventional buildings. In addition to these parameters, structural performance defined as a) no damage and light, b) moderate damage, c) heavy damage and collapse, as well as the number of storeys of each structure were used as to correlate structural damage with geotechnical earthquake engineering factors. As a conclusion series of vulnerability functions specific to Adapazari shaken by Kocaeli Earthquake were developed. Performance predictions of these vulnerability functions were shown to be consistent with as high as 65 percent of the observed structural performance.
16

The spatial distribution of Tsetse (Diptera: Glossinidae) within the Trypanosoma brucei rhodesiense focus of Uganda

Mugenyi, Albert Wafula January 2015 (has links)
One of the greatest problems for sub-Saharan Africa is shortage of epidemiological data to support planning for provision of adequate public and animal health services. The overriding challenge is to provide the necessary resources to facilitate the process of regular data collection in support of disease surveillance and vector monitoring across target regions. Due to such circumstances, there is currently an increasing interest towards devising cheaper but yet significantly reliable means for availing the needed epidemiological and vector data for planning purpose. This study comes as a contribution towards solving such challenges. The study has three research components starting with a review of past Uganda national tsetse and trypanosomiasis control efforts as a means towards appreciating the dynamics of controlling the vector and disease. This is an analysis of what was applied, what worked, what didn't, and why it didn’t as linked to the broader vector and disease control system. Secondly through the use of remote sensing, geographical information systems and global positioning technologies tsetse species were sampled within Lake Victoria Basin. Only two species of tsetse were trapped, G. f. fG. f. fuscipes which was widely distributed across the surveyed area, and G. Pallidipes which was detected in a few isolated locations close to the border with Kenya in Eastern Uganda. The analysis of land cover with tsetse findings showed an important association between G. f. fuscipes and particular vegetation mosaics. Unfortunately, while the results are highly informative, approaches for data collection such as this one are costly and unlikely to be sustained by the already over-burdened health systems in the low developed countries of Africa. The third and main part of this study investigates, demonstrates and delivers the possibilities of applying spatial epidemiological modelling techniques to produce both tsetse distribution and abundance maps. Four spatial and non-spatial regression models (Logistic, Autologistic, Negative binomial and Auto-negative binomial), were constructed and used to predict tsetse fly presence and tsetse fly abundance for the study area. The product is an improved understanding of association between environmental variables and tsetse fly distribution/abundance and maps providing continuous representations of the probability of tsetse occurrence and predicted tsetse abundance across the study area. The results indicate that tsetse presence and abundance are influenced differently. Tsetse abundance is highly determined by river systems while tsetse presence is majorly influenced by forested landscapes. Therefore, efforts to control trypanosomiasis through vector control in the Lake Victoria basin will call for delineation of such clearly identified high tsetse accumulation zones for targeted tsetse control operations. This will ensure optimum utilization of the scarce resources and above all contribute to the protection of humans and animals against trypanosomiasis infection.
17

Rainfall-runoff changes due to urbanization: a comparison of different spatial resolutions for lumped surface water hydrology models using HEC-HMS.

Redfearn, Howard Daniel 12 1900 (has links)
Hydrologic models were used to examine the effects of land cover change on the flow regime of a watershed located in North-Central Texas. Additionally, the effect of spatial resolution was examined by conducting the simulations using sub-watersheds of different sizes to account for the watershed. Using the Army Corps of Engineers, Hydrologic Engineering Center Hydrologic Modeling System (HEC-HMS), two different modeling methods were evaluated at the different sub-watershed resolutions for four rainfall events. Calibration results indicate using the smaller spatial resolutions improves the model results. Different scenarios for land cover change were evaluated for all resolutions using both models. As land cover change increased, the amount of flow from the watershed increased.
18

Use of geographic information systems for assessing ground water pollution potential by pesticides in central Thailand

Thapinta, Anat 08 1900 (has links)
This study employed geographic information systems (GIS) technology to evaluate the vulnerability of groundwater to pesticide pollution. The study area included three provinces (namely, Kanchana Buri, Ratcha Buri, and Suphan Buri) located in the western part of central Thailand. Factors used for this purpose were soil texture, percent slope, primary land use, well depth, and monthly variance of rainfall. These factors were reclassified to a common scale showing potential to cause groundwater contamination by pesticides. This scale ranged from 5 to 1 which means high to low pollution potential. Also, each factor was assigned a weight indicating its influence on the movement of pesticides to groundwater. Well depth, the most important factor in this study, had the highest weight of 0.60 while each of the remaining factors had an equal weight of 0.10. These factors were superimposed by a method called “arithmetic overlay” to yield a composite vulnerability map of the study area. Maps showing relative vulnerability of groundwater to contamination by pesticides were produced. Each of them represented the degree of susceptibility of groundwater to be polluted by the following pesticides: 2,4-D, atrazine, carbofuran, dicofol, endosulfan, dieldrin & aldrin, endrin, heptachlor & heptachlor epoxide, total BHC, and total DDT. These maps were compared to groundwater quality data derived from actual observations. However, only the vulnerability maps of atrazine, endosulfan, total BHC, and heptachlor & heptachlor epoxide showed the best approximation to actual data. It was found that about 7 to 8%, 83 to 88% and 4.9 to 8.7% of the study area were highly, moderately, and lowly susceptible to pesticide pollution in groundwater, respectively. In this study a vulnerability model was developed, which is expressed as follow: V = 0.60CW + 0.10CS + 0.10CR + 0.10CL + 0.10CSL. Its function is to calculate a vulnerability score for a certain area. The factor “V” in the model represents the vulnerability score of a certain area, whereas CW, CS, CR, CL, and CSL represent the values or classes assigned to well depth, soil texture, monthly variance of rainfall, primary land use, and percent slope in that area.
19

Next Generation EV Charging Infrastructure

Aziz, Selim 24 May 2022 (has links)
No description available.
20

Assessing the Performance of Water Bodies in Hillsborough County, Florida Using Data Envelopment Analysis (DEA)

Fouad, Geoffrey George 03 April 2009 (has links)
The purpose of this thesis is to describe the relationship between surface water quality and land use. Water management recommendations will be divulged based upon the interaction of lake water quality and land use. The methodology developed for this research applied Data Envelopment Analysis (DEA), a performance measurement tool, to evaluate lake water quality in relation to surrounding land use. Lake performance ratings were generated by DEA software that assessed multiple variables describing surface water nutrient loads and surrounding land use. Results from this analysis revealed a significant trend between lake water quality and land use within the study area. Lakes located within a two mile radius of more naturally preserved land area typically attained higher performance ratings than lakes located within a two mile radius of less naturally preserved land area. The spatial quantity of naturally preserved land influenced lake nutrient concentrations. Also, lake performance ratings generally declined in two mile radius delineations that contained less naturally preserved land area indicating a direct relationship between natural land area and lake performance.

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