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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.
571

Client-Server Communications Efficiency in GIS/NIS Applications : An evaluation of communications protocols and serialization formats / Kommunikationseffektivitet mellan klient och server i GIS/NIS-applikationer : En utvärdering av kommunikationsprotokoll och serialiseringsformat

Klingestedt, Kashmir January 2018 (has links)
Geographic Information Systems and Network Information Systems are important tools for our society, used for handling geographic spatial data and large information networks. It is therefore important to make sure such tools are of high quality. GIS/NIS applications typically deal with a lot of data, possibly resulting in heavy loads of network traffic. This work aims to evaluate two different communications protocols and serialization formats for client-server communications efficiency in GIS/NIS applications. Specifically, these are HTTP/1.1, HTTP/2, Java Object Serialization and Google's Protocol Buffers. They were each implemented directly into a commercial GIS/NIS environment and evaluated by measuring two signature server calls in the system. Metrics that were examined are call duration, HTTP overhead size and HTTP payload size. The results suggest that HTTP/2 and Google's Protocol Buffers outperform HTTP/1.1 and Java Object Serialization respectively. An 87% decrease in HTTP overhead size was achieved when switching from HTTP/1.1 to HTTP/2. The HTTP payload size is also shown to decrease with the use of Protocol Buffers rather than Java Object Serialization, especially for communications where data consist of many different object types. Concerning call duration, the results suggest that the choice of communications protocol is more significant than the choice of serialization format for communications containing little data, while the opposite is true for communications containing much data. / Geografiska informationssystem och nätverksinformationssystem är viktiga redskap för vårt samhälle, vilka används för hantering av geografisk data och stora informationsnätverk. Det är därför viktigt att se till att sådana system är av hög kvalitet. GIS/NIS-applikationer behandlar vanligtvis stora mängder data, vilket kan resultera i mycket nätverkstrafik. I det här arbetet utvärderas två olika kommunikationsprotokoll och serialiseringsformat för kommunikationseffektivitet mellan klient och server i GIS/NIS-applikationer. Specifikt är dessa HTTP/1.1, HTTP/2, Java Objektserialisering och Googles Protocol Buffers. De implementerades var och en i en kommersiell GIS/NIS-miljö och utvärderades genom mätningar av två signaturanrop i systemet. De aspekter som observerades är kommunikationstiden, mängden HTTP-overhead och mängden HTTP-payload. Resultaten tyder på att HTTP/2 och Googles Protocol Buffers presterar bättre än HTTP/1.1 respektive Java Objektserialisering. En 87% minskning av mängden HTTP overhead uppnåddes då HTTP/1.1 ersattes med HTTP/2. En minskning av mängden HTTP payload observeras också med användning av Protocol Buffers snarare än Java Objektserialisering, särskilt för kommunikationer där data innehåller många olika objekttyper. Gällande kommunikationstiden tyder resultaten på att valet av kommunikationsprotokoll påverkar mer än valet av serialiseringsformat för kommunikationer med små mängder data, medan motsatsen gäller för kommunikationer med mycket data.
572

Development of Traffic Safety Zones and Integrating Macroscopic and Microscopic Safety Data Analytics for Novel Hot Zone Identification

Lee, JaeYoung 01 January 2014 (has links)
Traffic safety has been considered one of the most important issues in the transportation field. With consistent efforts of transportation engineers, Federal, State and local government officials, both fatalities and fatality rates from road traffic crashes in the United States have steadily declined from 2006 to 2011.Nevertheless, fatalities from traffic crashes slightly increased in 2012 (NHTSA, 2013). We lost 33,561 lives from road traffic crashes in the year 2012, and the road traffic crashes are still one of the leading causes of deaths, according to the Centers for Disease Control and Prevention (CDC). In recent years, efforts to incorporate traffic safety into transportation planning has been made, which is termed as transportation safety planning (TSP). The Safe, Affordable, Flexible Efficient, Transportation Equity Act - A Legacy for Users (SAFETEA-LU), which is compliant with the United States Code, compels the United States Department of Transportation to consider traffic safety in the long-term transportation planning process. Although considerable macro-level studies have been conducted to facilitate the implementation of TSP, still there are critical limitations in macroscopic safety studies are required to be investigated and remedied. First, TAZ (Traffic Analysis Zone), which is most widely used in travel demand forecasting, has crucial shortcomings for macro-level safety modeling. Moreover, macro-level safety models have accuracy problem. The low prediction power of the model may be caused by crashes that occur near the boundaries of zones, high-level aggregation, and neglecting spatial autocorrelation. In this dissertation, several methodologies are proposed to alleviate these limitations in the macro-level safety research. TSAZ (Traffic Safety Analysis Zone) is developed as a new zonal system for the macroscopic safety analysis and nested structured modeling method is suggested to improve the model performance. Also, a multivariate statistical modeling method for multiple crash types is proposed in this dissertation. Besides, a novel screening methodology for integrating two levels is suggested. The integrated screening method is suggested to overcome shortcomings of zonal-level screening, since the zonal-level screening cannot take specific sites with high risks into consideration. It is expected that the integrated screening approach can provide a comprehensive perspective by balancing two aspects: macroscopic and microscopic approaches.
573

Monitorización de cambios en la lámina libre de agua en humedales mediante teledetección

Pena Regueiro, Jesús 07 September 2023 (has links)
Tesis por compendio / [ES] Los humedales son uno de los ecosistemas que reciben mayor atención por parte de la comunidad científica. Su importancia se puede explicar teniendo en cuenta que ayudan a mitigar los efectos de inundaciones, pueden actuar como filtros de agua y constituyen hábitats de valiosas especies de fauna y flora. En los últimos años este tipo de ambientes están cada vez más amenazados como consecuencia de la contaminación, alteraciones de los niveles de agua asociadas a los efectos del cambio climático y usos antrópicos, introducción de especies invasoras y los efectos negativos de algunos cambios de usos del suelo y determinadas prácticas asociados a ellos (agrícolas, pastoreo y urbanización). Para analizar estos ecosistemas, la teledetección se presenta como una herramienta con alto potencial que permite identificar, evaluar y monitorizar estos espacios. En esta tesis se utilizaron imágenes Sentinel-2A/B, Landsat-5 TM y Landsat-8 OLI para extraer láminas de agua libre en dos entornos: humedales mediterráneos costeros (Prat Cabanes-Torreblanca, Marjal de Sagunto, Marjal de La Safor y Marjal Pego-Oliva) y el humedal de llanura aluvial situado en el centro de España las Tablas de Daimiel. Para ello, se realizó un análisis de siete índices de agua (NDWI, mNDWI, Cedex, Re-NDWI, Awei(sh), AWEI (nsh) y B_Blue) y de umbrales para obtener la cartografía de las masas de agua libre en estos espacios. El objetivo principal es definir el índice y el umbral que permitan un uso más amplio de la metodología para su aplicación en otras zonas húmedas. También se utilizó información LiDAR (Laser Imaging Detection and Ranging) en el humedal de La Safor para analizar los efectos de la superficie inundada en diferentes usos del suelo. La evaluación de los resultados se realizó a partir de la validación con un conjunto de muestras obtenidas a partir de imágenes de elevada resolución espacial. Se calcularon la fiabilidad global y el índice kappa en los humedales analizados para distintas fechas y sensores. En el caso de los humedales costeros, el índice de agua NDWI con un umbral de ¿0,30 proporcionó los resultados con mayor precisión obteniendo un valor promedio de 0,89 en fiabilidad global. En el caso del humedal de las Tablas de Daimiel, se seleccionaron el índice MNDWI y umbral ¿0,15 para imágenes Landsat-5 (fiabilidad global 0,88), el índice MNDWI y umbral ¿0,25 para imágenes Landsat-8 (fiabilidad global 0,99) y el índice NDWI y umbral ¿0,20 (fiabilidad global 0,99) en el caso de imágenes Sentinel-2A/B. En el humedal de las Tablas de Daimiel se realizó un análisis temporal desde el año 2000 al 2021 que permitió calcular las anomalías de la superficie de agua, de la precipitación, del nivel piezométrico y del caudal hidrológico. Esta reconstrucción temporal también permitió comparar los resultados derivados a partir de las imágenes Sentinel-2A/B y de las imágenes Landsat 8. Se realizó un análisis de correlación entre los índices de anomalías calculados, que revela una correlación no significativa entre las anomalías precipitación y de superficie de agua. Mientras que el índice de anomalías de superficie de agua si presentó una correlación estadísticamente significativa con los índices de anomalía de caudal y de niveles piezométricos. En cuanto al análisis comparativo entre las imágenes Landsat-8 y Sentinel-2 se obtuvo una relación lineal entre la superficie de agua estimada por ambos sensores con un valor de R2 = 0,87. No obstante, la mayor resolución espacial de Sentinel-2 permite detectar masas de agua más pequeñas contribuyendo a un mejor análisis de los patrones de variabilidad en el área de estudio. La información derivada de esta tesis presenta una aplicabilidad de interés medioambiental para el seguimiento del estado de los humedales ayudando a adaptar planes de gestión que conduzcan a un estado de conservación adecuado. / [CA] Els aiguamolls són un dels ecosistemes que reben major atenció per part de la comunitat científica. La seua importància es pot explicar tenint en compte que ajuden a mitigar els efectes d'inundacions, poden actuar com a filtres d'aigua i constitueixen hàbitats de valuoses espècies de fauna i flora. En els últims anys aquest tipus d'ambients estan cada vegada més amenaçats a conseqüència de la contaminació, alteracions dels nivells d'aigua associades a l'efecte del canvi climàtic i usos antròpics, introducció d'espècies invasores i els efectes negatius d'alguns canvis d'usos del sòl i determinades pràctiques associades a ells (agrícoles, pasturatge i urbanització). Per a analitzar aquests ecosistemes, la teledetecció es presenta com una eina amb alt potencial que permet identificar, avaluar i monitorar aquests espais. En aquesta tesi es van utilitzar imatges Sentinel-2A/B, Landsat-5 TM i Landsat-8 OLI per a extraure làmines d'aigua lliure en dos entorns: aiguamolls mediterranis costaners (Prat Cabanes-Torreblanca, Marjal de Sagunt, Marjal de La Safor i Marjal Pego-Oliva) i l'aiguamoll de plana al·luvial situat en el centre d'Espanya les Taules de Daimiel. Per a això, es va realitzar una anàlisi de set índexs d'aigua (NDWI, mNDWI, Cedex, Re-NDWI, Awei (sh), AWEI (nsh) i B_Blue) i de llindars per a obtindre la cartografia de les masses d'aigua lliure en aquests espais. L'objectiu principal és definir l'índex i el llindar que permeten un ús més ampli de la metodologia per a la seua aplicació en altres zones humides. També es va utilitzar informació LiDAR (Laser Imaging Detection and Ranging) en l'aiguamoll de La Safor per a analitzar els efectes de la superfície inundada en diferents usos del sòl. L'avaluació dels resultats es va realitzar a partir de la validació amb un conjunt de mostres obtingudes a partir d'imatges d'elevada resolució espacial. Es van calcular la fiabilitat global i l'índex kappa en els aiguamolls analitzats per a diferents dates i sensors. En el cas dels aiguamolls costaners, l'índex d'aigua NDWI amb un llindar de ¿0,30 va proporcionar els resultats amb major precisió obtenint un valor mitjà de 0,89 en fiabilitat global. En el cas de l'aiguamoll de les Taules de Daimiel, es van seleccionar l'índex MNDWI i llindar ¿0,15 per a imatges Landsat-5 (fiabilitat global 0,88), l'índex MNDWI i llindar ¿0,25 per a imatges Landsat-8 (fiabilitat global 0,99) i l'índex NDWI i llindar ¿0,20 (fiabilitat global 0,99) en el cas d'imatges Sentinel-2A/B. En l'aiguamoll de les Taules de Daimiel es va realitzar una anàlisi temporal des de l'any 2000 al 2021 que va permetre calcular les anomalies de la superfície d'aigua, de la precipitació, del nivell piezomètric i del cabal hidrològic. Aquesta reconstrucció temporal també va permetre comparar els resultats derivats a partir de les imatges Sentinel-2A/B i de les imatges Landsat 8. Es va realitzar una anàlisi de correlació entre els índexs d'anomalies calculats, que revela una correlació no significativa entre les anomalies precipitació i de superfície d'aigua. Mentre que l'índex d'anomalies de superfície d'aigua si va presentar una correlació estadísticament significativa amb els índexs d'anomalia de cabal i de nivells piezomètrics. Quant a l'anàlisi comparativa entre les imatges Landsat-8 i Sentinel-2 es va obtindre una relació lineal entre la superfície d'aigua estimada per tots dos sensors amb un valor de R2 = 0,87. No obstant això, la major resolució espacial de Sentinel-2 permet detectar masses d'aigua de menor grandària contribuint a una millor anàlisi dels patrons de variabilitat en l'àrea d'estudi. La informació derivada d'aquesta tesi presenta una aplicabilitat d'interés mediambiental per al seguiment de l'estat dels aiguamolls ajudant a adaptar plans de gestió que condueixen a un estat de conservació adequat. / [EN] Wetlands are one of the ecosystems that receive the most attention from the scientific community. Their importance can be explained by the fact that they help mitigate the effects of flooding, can act as water filters, and provide habitats for valuable species of fauna and flora. In recent years, these types of environments are increasingly threatened as a result of pollution, alterations in water levels associated with the effects of climate change and anthropic uses, the introduction of invasive species and the negative effects of some changes in land use and certain practices associated with them (agriculture, grazing and urbanization). To analyze these ecosystems, remote sensing is presented as a tool with high potential to identify, evaluate and monitor these areas. In this thesis, Sentinel-2A/B, Landsat-5 TM and Landsat-8 OLI images were used to extract free water bodies in two environments: coastal Mediterranean wetlands (Prat Cabanes-Torreblanca, Marjal de Sagunto, Marjal de La Safor and Marjal Pego-Oliva) and the alluvial plain wetland located in the center of Spain, the Tablas de Daimiel. For this purpose, an analysis of seven water indices (NDWI, mNDWI, Cedex, Re-NDWI, Awei (sh), AWEI (nsh) and B_Blue) and thresholds were carried out to obtain the mapping of free water bodies in these areas. The main objective is to define the index and threshold that allow a wider use of the methodology for its application in other wetlands. LiDAR (Laser Imaging Detection and Ranging) information was also used in La Safor wetland to analyze the effects of the flooded surface on different land uses. The evaluation of the results was carried out based on the validation with a set of samples obtained from high spatial resolution images. The overall accuracy and the kappa index were calculated for the wetlands analyzed for different dates and sensors. In the case of the coastal wetlands, the NDWI water index with a threshold of ¿0.30 provided the most accurate results with an average value of 0.89 in global accuracy. In the case of Las Tablas de Daimiel wetland, the MNDWI index and threshold ¿0.15 were selected for Landsat-5 images (overall accuracy 0.88), the MNDWI index and threshold ¿0.25 for Landsat-8 images (overall accuracy 0.99) and the NDWI index and threshold ¿0.20 (overall accuracy 0.99) in the case of Sentinel-2A/B images. In Las Tablas de Daimiel wetland, a temporal analysis was carried out from 2000 to 2021 to calculate the anomalies of the water surface, precipitation, piezometric level and hydrological flow. This temporal reconstruction also made it possible to compare the results derived from Sentinel-2A/B images and Landsat 8 images. A correlation analysis was performed between the calculated anomaly indices, which revealed a non-significant correlation between the precipitation and water surface anomalies. However, the water surface anomaly index did show a statistically significant correlation with the flow anomaly and piezometric level indexes. As for the comparative analysis between Landsat-8 and Sentinel-2 images, a linear relationship was obtained between the water surface estimated by both sensors with a value of R2 = 0.87. However, the higher spatial resolution of Sentinel-2 allows the detection of smaller water masses contributing to a better analysis of the variability patterns in the study area. The information derived from this thesis presents an application of environmental interest for monitoring the state of wetlands helping to adapt management plans that lead to an adequate conservation status. / Pena Regueiro, J. (2023). Monitorización de cambios en la lámina libre de agua en humedales mediante teledetección [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/196109 / Compendio
574

Evaluating the potential of truck electrification and its implementation from user and agency perspectives

Theodora Konstantinou (5930705) 27 July 2022 (has links)
<p>  </p> <p>The trucking industry seems to be resistant to electrification, even though truck electrification can lead to large societal as well as user benefits. This dissertation develops a framework to inform policy making and enhance electric vehicle (EV) preparedness in the trucking industry through the study of two interrelated elements: (a) the adoption of electric trucks and (b) the appropriate implementation of electric truck technology. These two elements cover the user perspective, which is not adequately studied, and the agency perspective, which is pivotal in the decision-making process. Specifically, this study addressed the following research questions: (i) which factors affect the purchase decisions of truck fleet managers or owners for electric trucks? (ii) what is the ranking of and interrelationships between the barriers to the adoption of electric trucks? (iii) which location criteria should be considered for the strategic implementation of dynamic wireless charging (DWC) in a freight transportation network and where should this technology be located based on these criteria, and (iv) what is the impact of electric truck adoption on highway revenue and potential of alternative funding mechanisms to recover the revenue loss?</p> <p>For the adoption of electric trucks, a stated preference survey was designed and distributed online to truck fleet managers/owners in the U.S., gathering 200 completed responses. Statistical and multi-criteria decision-making approaches were employed to identify the factors that affect the purchase intentions of truck fleet managers and explore the barriers to electric truck adoption. The results showed that the purchase intentions of truck fleet managers are affected by trucking firm and truck fleet characteristics, behavioral factors/opinions regarding electric trucks, and awareness of innovative charging technologies. Furthermore, electric truck adoption would be accelerated if stakeholders focused on the barriers related to the business model, product availability, and charging time. Additionally, electric truck adopters and non-adopters may not be viewed as one homogenous group, since differences were found in the ranking and interrelationships of barriers to electric truck adoption between these two groups. </p> <p>The implementation of electric truck technology was examined based on the truck fleet managers’ survey, secondary data sources and the case of Indiana, U.S. A multi-criteria decision-making spatial approach was proposed to identify the candidate locations for the deployment of DWC. It was concluded that the most suitable locations for DWC lanes were on interstates, near airports and ports and away from EV charging stations. A data-driven framework was also developed to quantify the impact of electric truck adoption and estimate the optimal fee for each truck to recover the revenue loss. Using the market penetration levels estimated based on the survey data collected, the average annual fuel tax revenue loss for Indiana was approximately $349M. To maintain the same tax revenue per vehicle, annual fees ranging from $969 (in 2021) to $1,243 (in 2035) for single-unit trucks and $6,192 to $7,321 for combination trucks would be needed. To address public relations problems of EV fee implementation, this study also discussed alternative mitigation measures: a vehicle-miles-traveled fee and a pay-as-you-charge fee.</p> <p>In summary, this dissertation contributes to the body of literature by providing significant insights regarding the perspectives of truck fleet managers for electric trucks as well as a comprehensive list of all the location criteria for DWC. The proposed frameworks and study findings can be used by policymakers and other major stakeholders of the EV ecosystem to frame certain strategies to accelerate electric truck adoption, identify the most suitable locations for charging infrastructure, better understand the impact of electric trucks on the highway revenue, and provide the groundwork for developing EV roadmaps.</p>
575

Bivariate Best First Searches to Process Category Based Queries in a Graph for Trip Planning Applications in Transportation

Lu, Qifeng 22 April 2009 (has links)
With the technological advancement in computer science, Geographic Information Science (GIScience), and transportation, more and more complex path finding queries including category based queries are proposed and studied across diverse disciplines. A category based query, such as Optimal Sequenced Routing (OSR) queries and Trip Planning Queries (TPQ), asks for a minimum-cost path that traverses a set of categories with or without a predefined order in a graph. Due to the extensive computing time required to process these complex queries in a large scale environment, efficient algorithms are highly desirable whenever processing time is a consideration. In Artificial Intelligence (AI), a best first search is an informed heuristic path finding algorithm that uses domain knowledge as heuristics to expedite the search process. Traditional best first searches are single-variate in terms of the number of variables to describe a state, and thus not appropriate to process these queries in a graph. In this dissertation, 1) two new types of category based queries, Category Sequence Traversal Query (CSTQ) and Optimal Sequence Traversal Query (OSTQ), are proposed; 2) the existing single-variate best first searches are extended to multivariate best first searches in terms of the state specified, and a class of new concepts--state graph, sub state graph, sub state graph space, local heuristic, local admissibility, local consistency, global heuristic, global admissibility, and global consistency--is introduced into best first searches; 3) two bivariate best first search algorithms, C* and O*, are developed to process CSTQ and OSTQ in a graph, respectively; 4) for each of C* and O*, theorems on optimality and optimal efficiency in a sub state graph space are developed and identified; 5) a family of algorithms including C*-P, C-Dijkstra, O*-MST, O*-SCDMST, O*- Dijkstra, and O*-Greedy is identified, and case studies are performed on path finding in transportation networks, and/or fully connected graphs, either directed or undirected; and 6) O*- SCDMST is adopted to efficiently retrieve optimal solutions for OSTQ using network distance metric in a large transportation network. / Ph. D.
576

GIS-baserad analys över gång- och cykelvägnät : En GIS-analys med avseende på säkerhet och tillgänglighet över gång- och cykelvägnätet i Vänersborgs kommun / GIS-based analysis of pedestrian and cycle path : A GIS analysis of the security and accessibility of pedestrian and bicyclenetwork in the urban areas of the municipality of Vänersborg

Johansson, Paulina, Olsson, Elias January 2024 (has links)
Förbättring av cykling som hållbart transportmedel kräver skräddarsydda transportsystem. Svenska kommuner, som Vänersborgs, har påbörjat implementering av cykelplaner vid planering av infrastruktur. Med kommunens samtida mål om att öka invånarantalet från 39 000 till 50 000, är planens mål och riktlinjer för att utveckla ett högkvalitativt, säkert cykelvägnät som kopplar samman viktiga målpunkter och minskar olyckor. Denna avhandling utvärderar säkerheten och tillgängligheten över gång- och cykelvägnätet till skolor inom Vänersborgs kommun med hjälp av GIS-analyser, där fokus riktar mot barn i åldrarna 7–15 år, men även säkerheten över totala gång- och cykelvägnätet utvärderas. Studieområdet inkluderar Vänersborgs centrum, Öxnered och Vargön. Multikriterieanalys (Analytisk Hierarkisk Process) metoder med kombination av nätverksanalys användes för att bedöma GC-nätets säkerhet och tillgänglighet. Experter viktade olika kriterier för säkerhet, vilket ledde till säkerhetsklassificering i ArcGIS Pro. Inkluderade kategorier var Mycket god, god, mindre god och låg. Nätverksanalysen i ArcGIS Pro prioriterade rutter via gång- och cykelvägnätet och förbjöd rutter att färdas längs vägar med hastigheter över 80 km/h, med hjälp av verktyget Closest facility för att planera rutter till skolan och undersöka tillgängligheten. Resultaten visade att 48.33% av det totala GC-nätet klassificerades som mycket god, 1.89% som god, 26.14% mindre god och 23.64% som låg. Nätverksanalysen indikerade en tillgänglighet till skolor uppnår 73.98%. Trots en signifikant andel av GC-nätet uppnår mycket god säkerhetsnivå, noterades brister, specifikt vid mer urbana områden där vissa segment klassas som mindre god och låg. Sammantaget visar avhandlingen att medan GC-nätet generellt uppnår god säkerhet och tillgänglighet, förekommer märkbara brister. Att se över och eventuellt åtgärda dessa brister skulle främja utvecklingen av cyklandet i Vänersborgs kommun. / Enhancing bicycling as a sustainable transportation mode requires tailored transportation systems. Swedish municipalities such as Vänersborg are integrating bicycling into infrastructure planning. The municipality's aims to grow the population from 39,000 to 50,000, the plan aims to develop a high-quality, safe bicycle network connecting key destinations and reducing accidents. This thesis evaluates the safety and accessibility of the bicycle network to schools within Vänersborg municipality using GIS-based analyses, focusing on children aged 7 to 15, while also evaluating the safety of the total network. The study area includes Vänersborgcity center, Öxnered, and Vargön. Multi-Criteria Decision Making (Analytical Hierarchy Process) approaches coupled with network analysis were utilized to assess the network's security and accessibility. Experts weighted different security criteria, leading to a safety classification in ArcGIS Pro. Categories included very good, good, not so good, and low. The Network analysis in ArcGIS Pro prioritized bicycle routes and restricted roads with speed limits over 80 km/h, using the Closest Facility tool to route school access. The results indicated that 48.33% of the network was classified as very good, 1.89% asgood, 26.14% as not so good, and 23.64% as low. The network analysis indicated a 73.98% accessibility coverage to schools. Despite a significant portion of the network achieving a very good safety level, deficiencies were noted, particularly in urban areas where some sections were rated as not so good and low. Overall, the thesis reveals that while the bicycle network generally achieves good security and accessibility, there are notable shortcomings. Addressing these gaps is crucial for Vänersborg's efforts to promote cycling and support population growth.
577

Plant communities in organic and conventional agriculture - comparing local, landscape and regional effects / Ackerwildpflanzengesellschaften in ökologischer und konventioneller Landwirtschaft - die Bedeutung von Standort, Landschaft und Region

Gabriel, Doreen 03 February 2006 (has links)
No description available.
578

都市域の総合的地震被災ポテンシャルの定量化に基づく地域防災カルテの作成

福和, 伸夫, 森, 保宏, 飛田, 潤, 中野, 優, 中井, 正一, 勝倉, 裕, 川端, 寛文, 高堂谷, 正樹 03 1900 (has links)
科学研究費補助金 研究種目:基盤研究(B)(2) 課題番号:11555149 研究代表者:都市域の総合的地震被災ポテンシャルの定量化に基づく地域防災カルテの作成 研究期間:1999-2001年度
579

Tidal sedimentology and geomorphology in the central Salish Sea straits, British Columbia and Washington State

Mullan, Sean 03 January 2018 (has links)
Intra-archipelago waterways, including tidal strait networks, present a complex set of barriers to, and conduits for sediment transport between marine basins. Tidal straits may also be the least well understood tide-dominated sedimentary environment. To address these issues, currents, sediment transport pathways, and seabed sedimentology & geomorphology were studied in the central Salish Sea (Gulf and San Juan Islands region) of British Columbia, Canada and Washington State, USA. A variety of data types were integrated: 3D & 2D tidal models, multibeam bathymetry & backscatter, seabed video, grab samples, cores and seismic reflection. This dissertation included the first regional sediment transport modelling study of the central Salish Sea. Lagrangian particle dispersal simulations were driven by 2D tidal hydrodynamics (~59-days). It was found that flood-tide dominance through narrow intra-archipelago connecting straits resulted in the transfer of sediment into the inland Strait of Georgia, an apparent sediment sink. The formative/maintenance processes at a variety of seabed landforms, including a banner bank with giant dunes, were explained with modelled tides and sediment transport. Deglacial history and modern lateral sedimentological and morphological transitions were also considered. Based on this modern environment, adjustments to the tidal strait facies model were identified. In addition, erosion and deposition patterns across the banner bank (dune complex) were monitored with 8-repeat multibeam sonar surveys (~10 years). With these data, spatially variable bathymetric change detection techniques were explored: A) a cell-by-cell probabilistic depth uncertainty-based threshold (t-test); and B) coherent clusters of change pixels identified with the local Moran's Ii spatial autocorrelation statistic. Uncertainty about volumetric change is a considerable challenge in seabed change research, compared to terrestrial studies. Consideration of volumetric change confidence intervals tempers interpretations and communicates metadata. Techniques A & B may both be used to restrict volumetric change calculations in area, to exclude low relative bathymetric change signal areas. / Graduate / 2018-12-07
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Flächennutzungsmonitoring [I]: Konzepte - Indikatoren - Statistik

Meinel, Gotthard, Schumacher, Ulrich January 2009 (has links)
Grundlage des Buches sind die Beiträge des 1. Dresdner Flächennutzungssymposiums. Dieses ist der Auftakt für eine zukünftig jährlich stattfindende Fachtagung, die Wissenschaft und Praxis zu Fragen der Erhebung, Entwicklung und Prognose der Flächennutzungsentwicklung zusammenführt. Das 1. Buch der beginnenden Reihe „Flächennutzungsmonitoring“ informiert über die amtliche Flächenstatistik einschließlich deren Datengrundlage und alternativer Datengrundlagen für die Flächenerhebung. In diesem Zusammenhang werden auch Indikatoren zur Beschreibung der Flächeninanspruchnahme und der Freiraumentwicklung vorgestellt. Da es hier auch immer wieder um Fragen der Visualisierung geht, werden Verfahren zur kleinräumigen Darstellung von Zustand und Entwicklung von Indikatoren auf verschiedenen räumlichen Ebenen bis hin zu Rasterkarten erläutert. Im abschließenden Beitrag geht es um die Konzeption eines Monitors der Siedlungs- und Freiraumentwicklung auf Grundlage von geotopographischen Basisdaten.

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