Visual Topology is used here to describe the spatial relations between objects as they appear in the 2D viewing plane. This thesis sets out the concept, explains why it is needed in Geographic Information Science and suggests how it may be computed through development of prototype software. Section 1 considers the functionality that any Spatial Data Infrastructure would need to encompass in order to support the inclusion of visual analysis into landscape planning and monitoring systems. Section 2 introduces various aspects of visual topology. In particular it sets out how visual intersections of occluding edges may be modelled topologically and formally defines a novel higher level topological structure to the viewing space - the 'Euler Zone' based on the Euler complexity of a graph formed by the occluding horizons in a view. Whether such a graph has meaning to an observer is considered in Section 5, which presents the results of a web based forced­ choice experiment with significant implications for the role of topology in modelling landscape preference via quantitative metrics derived from 20 maps. Sections 3 and 4 discuss how existing methods for handling perspective models and visualisations need to be improved in order to model visual topology. Section 3 focuses on the limitations of current techniques and design criterion for a new methodology. Section 4 looks at the lessons learnt from developing a prototype implementation (VM-LITE) based on Quad-Edge Delaunay Triangulation, in the VoronoiMagic software package. Some potential applications are highlighted, both within landscape modelling and beyond, before drawing conclusions as to the potential for the concepts and methods respectively. Although important research questions remain, particularly as regards view point dynamics, Visual Topology has the potential to fundamentally change how visual modelling is undertaken in GIS. It allows the analysis of scenes based upon a richer representation of individual experience. It provides the basis for data structures that can support the extraction of generalisable metrics from this rich scene information, taking into account the qualitatively different nature of scene topology as distinct from metrics of shape and colour. In addition new metrics based on attributes only apparent in perspective, such as landform, can be analysed. Finally, it also provides a rationale for reporting units for landscapes with some measure of homogeneity and scale-independence in their scenic properties.

No description available.

The diploma thesis "Strategic Defense Initiative" deals with the issue of the Strategic initiative on the basis of historical-political analysis. The SDI was a crucial topic during the 80s, which had political impacts on the development of the international events and the Cold war in general. This work presents brief history of the United States ABM systems and introduced historical context. Furthermore, the author analyzes possible reasons for the SDI announcement and reexamines Reagan's speech from March 1983. Persons and interest groups who were promoting strategic defense are also included in this analysis. Problems connected to the SDI and its brief description are also mentioned. The following chapter deals with Soviet reaction to the SDI. The seventh chapter dicusses the European reaction to the SDI. The topic is analyzed on the example of United Kingdom. Next chapter deals with the Anti Ballistic Missile treaty and its interpretations from the SDI prespective. Last chapter discusses US - Soviet summits which took place in the 80s with emphasis on the SDI.

With a constant increase of the datasphere so does the need for proper management of this data in order to minimise potential inefficiencies when it comes to the usage of this data. Geodata is no exception to the need of management.  The purpose of this thesis was to investigate the current challenges of geodata management in Swedish companies and public authorities through qualitative analysis by interviews. Geodata- and GIS-users from the public and private sector made up the pool of interviewees and a total of 20 interviews were conducted. Despite a large diversity of daily tasks at hand, from data transfer for a customer in a system change process to updating attributes in NIS tools, all of the interviewees had some degree of challenges with respect to management of geodata. The results showed that the main challenges regarded inadequate or lack of quality geodata and its metadata as well as clarity of the location of these datasets. Scarcity of common understanding of geodata and GIS-systems among colleagues of geodata- and GIS-users causes these colleagues to often deliver incorrect, poorly formatted or low quality geodata and metadata. A large number of geodata file formats also contributes to confusion amongst geodata- and GIS-users and non-users which directly and indirectly causes some inefficiency. It was determined that the challenges of geodata management are highly abundant in the Swedish public and private sector. Furthermore, it was evaluated that the possible solutions would be to simplify geodata with less file formats as well as better and more clear coordination at organisational levels. Educating non-geodata and GIS-users in the workforce as well as in higher educational institutions that have majors related to geodata was also suggested as a possible solution to minimise challenges.

4 pp. / Converting from Gallons -- to Inches -- to Runtime Hours for Row Crop Drip Irrigation Systems / Many growers in Arizona are switching from surface to drip irrigation. This change requires many changes in water management. One of the changes that growers are having the most difficulty with is the concept of applying gallons of water instead of inches. This paper helps growers make this conversion from inches to gallons and then back again. An accompanying EXCEL program, available on the web, will help growers determine run times and application amounts.

4 pp. / Many growers in Arizona are switching from surface to drip irrigation. This change requires many changes in water management. One of the changes that growers are having the most difficulty with is the concept of applying gallons of water instead of inches. This paper helps growers make this conversion from inches to gallons and then back again. An accompanying EXCEL program, available on the web, will help growers determine run times and application amounts.

Revised; Originally Published: 2007 / 4 pp.

De nos jours, l'information géographique constitue une ressource incontournable dans un contexte de prise de décision et les données numériques spatiales sont de plus en plus fréquemment exploitées comme support et aide à la décision par de nombreuses organisations.<br />L'institution militaire utilise elle aussi les données spatiales comme soutien et aide à la décision. A chaque étape d'une mission, des informations géographiques de tous types sont employées (données numériques, cartes papiers, photographies aériennes...) pour aider les unités dans leurs choix stratégiques. Par ailleurs, l'utilisation de réseaux de communication favorise le partage et l'échange des données spatiales entre producteurs et utilisateurs situés à des endroits différents. L'information n'est pas centralisée, les données sont répliquées sur chaque site et les utilisateurs peuvent ponctuellement être déconnectés du réseau, par exemple lorsqu'une unité mobile va faire des mesures sur le terrain.<br />La problématique principale concerne donc la gestion dans un contexte militaire, d'une application collaborative permettant la mise à jour asynchrone et symétrique de données géographiques répliquées selon un protocole à cohérence faible optimiste. Cela nécessite de définir un modèle de cohérence approprié au contexte militaire, un mécanisme de détection des mises à jour conflictuelles lié au type de données manipulées et des procédures de réconciliation des écritures divergentes adaptées aux besoins des unités participant à la mission.<br />L'analyse des travaux montre que plusieurs protocoles ont été définis dans les communautés systèmes (Cederqvist :2001 ; Kermarrec :2001) et bases de données (Oracle :2003 ; Seshadri :2000) pour gérer la réplication des données. Cependant, les solutions apportées sont souvent fonctions du besoin spécifique de l'application et ne sont donc pas réutilisables dans un contexte différent, ou supposent l'existence d'un serveur de référence centralisant les données. Les mécanismes employés en information géographique pour gérer les données et les mises à jour ne sont pas non plus appropriés à notre étude car ils supposent que les données soient verrouillées aux autres utilisateurs jusqu'à ce que les mises à jour aient été intégrée (approche check in-check out (ESRI :2004), ou utilisent un serveur centralisé contenant les données de référence (versionnement : Cellary :1990).<br />Notre objectif est donc de proposer des solutions permettant l'intégration cohérente et autant que possible automatique, des mises à jour de données spatiales dans un environnement de réplication optimiste, multimaître et asynchrone.<br />Nous proposons une stratégie globale d'intégration des mises à jour spatiales basée sur une vérification de la cohérence couplé à des sessions de mises à jour. L'originalité de cette stratégie réside dans le fait qu'elle s'appuie sur des métadonnées pour fournir des solutions de réconciliation adaptées au contexte particulier d'une mission militaire.<br />La contribution de cette thèse est double. Premièrement, elle s'inscrit dans le domaine de la gestion de la mise à jour des données spatiales, domaine toujours très actif du fait de la complexité et de l'hétérogénéité des données (Nous limitons néanmoins notre étude aux données géographiques vectorielles) et de la relative «jeunesse » des travaux sur le sujet. Deuxièmement, elle s'inscrit dans le domaine de la gestion de la cohérence des données répliquées selon un protocole optimiste, en spécifiant en particulier, de nouveaux algorithmes pour la détection et la réconciliation de données conflictuelles, dans le domaine applicatif de l'information géographique.

<p>A Spatial Data Infrastructure (SDI) is required to make the spatial data be fully used and well shared by the society. In China, SDI’s has also been established progressively. A thorough understanding of the potentials and shortcomings about SDI in China has a positive significance to clearly identify the future direction and actions.In order to find out the potentials and shortcomings of SDI in China, the current situation of SDI and SDI in China have been assessed through literature review and interview. Then a Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis has been developed. Based on the current experiences of SDI development in China, the thesis concludes that China have a good potential to develop its SDI function. It also points out that there still are some weaknesses needed to be surmounted, such as: lacking advanced technology, data duplication, and lack of skilled workforce. There is a big room and capability to improve the development of Chinese SDI well in the future.</p>

This thesis seeks to review Urban Sustainability in cities of the Developing South within the broader spectrum of Sustainable Development. Notably, the Developing South has for many years struggled to embrace Sustainability in its general terms: in part, because of the fragile institutions that cannot be counted on to uphold sustainability in the truest sense of the word; and in part because of the numerous challenges that often distract any attempt to prioritize Sustainable Development. Sustainability then becomes an option in the midst of other options, rather than an option that should affect all other options. Narrowing it down further to matters urban makes it even stranger in a host of cities across the Developing South. It is against this backdrop that this study seeks to examine in depth the contextual challenges that have invariably stood in the way of Sustainable Development across the Developing South. While it may not be practically possible in a four-month study to offer outright solutions or recommendations that could address these challenges in entirety, this study nevertheless has endeavoured to stay true to the realities that are often ignored whenever challenges of Sustainable Development are mentioned on global platforms. Among these realities is the reality of slum presence in most cities of the Developing South that existentially complicates any equation for urban sustainability ever formulated to provide a way out or forward for these cities. State governments understand this too well, and so do Civil Society Organizations (CSOs) and international organizations alike involved in the crusade for improved living conditions for city resident, and in particular slum residents. Yet the State governments have never been as resolute in their quest for slum free cities. The question then remains: exactly what are the sustainable approaches for this noble cause? While the State governments have over the years insisted on enforcing conventional approaches (that include forced evictions, relocations and/ or redevelopment); one international network, however, thinks and responds differently to slum situations. The network is Shack/Slum Dwellers International (SDI). It is considerably this network of slum dwellers and their undeniably innovative approach to urban sustainability and inclusivity that largely frames the direction and general content of this study. Specifically, the methodology adopted in the study is one of a Case study - which in this case is SDI; and two separate Cases, namely Railway Relocation Action Plan (RAP) in Nairobi, Kenya and slum Re-blocking project in Joe Slovo, Cape Town, South Africa, respectively - as typical cases that captures in large part the enormous contribution that SDI is making towards inclusive and sustainable cities in the Developing South. In the discussion part, however, the study introduces Soft Systems Methodology (SSM) as a comparative methodology to SDI’s approach. SSM particularly benefits from LUMAS model and Social Learning – both key components that potentially reserve a dynamic capacity to enriching SDI’s approach as a future reference methodology for urban sustainability and inclusivity.