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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.
341

Observations of solar wind related climate effects in the Northern Hemisphere winter

Maliniemi, V. (Ville) 21 December 2016 (has links)
Abstract This thesis studies the long-term relation between the solar wind driven energetic particle forcing into the atmosphere and the tropospheric circulation in the Northern Hemisphere winter. The work covers the period of more than one hundred years since the turn of the 20th century to present. The thesis makes a statistical analysis of satellite measurements of precipitating energetic electrons, sunspot number data and geomagnetic activity, and compares them with temperature and pressure measurements made at the Earth's surface. Recent results, both observational and from chemistry climate models, have indicated significant effects in the Earth's middle atmosphere due to the energetic electrons precipitating from the magnetosphere. These effects include the formation of reactive hydrogen and nitrogen oxides in the high latitude mesosphere and the depletion of ozone caused by them. Ozone is a radiatively active and important gas, which affects the thermal structure and dynamics of the middle atmosphere. Accordingly, the depletion of ozone can intensify the large scale stratospheric circulation pattern called the polar vortex. Winter weather conditions on the surface have been shown to be dependent on the polar vortex strength. This thesis shows that there is a significant relation between the average fluxes of medium energy (ten to hundred keVs) precipitating electrons and surface temperatures in parts of the Northern Hemisphere in winter time. Temperatures are positively correlated with electron fluxes in North Eurasia and negatively correlated in Greenland during the period 1980-2010 which is covered by direct satellite observations of precipitating particles. This difference is especially notable when major sudden stratospheric warmings and the quasi-biennial oscillation (QBO), which both are known to affect the polar vortex strength, are taken into account. When extended to the late 19th century, the analysis shows that a similar temperature pattern is predominated during the declining phase of the sunspot cycle. The high speed solar wind streams and energetic particle precipitation typically maximize also at the declining phase of the solar cycle. This specific temperature pattern is related to the variability of the northern annular mode (NAM), which is the most significant circulation pattern in the Northern Hemisphere winter. Before the space era, geomagnetic activity measured by ground observations can be used as a proxy for energetic particle precipitation. Earlier studies have found a significant positive correlation between geomagnetic activity and NAM since the 1960s. We find that, when the QBO measured at 30 hPa height is in the easterly phase, a positive correlation is extended to the beginning of 1900s. We also show that high geomagnetic activity causes a stronger effect in the Northern Hemisphere winter than high sunspot activity, especially in the Atlantic and Eurasia. A comprehensive knowledge of the Earth's climate system and all its drivers is crucial for the future projection of climate. Solar variability effects have been estimated to produce only a small factor to the global climate change. However, there is increasing evidence, including the results presented in this thesis, that the different forms of solar variability can have a substantial effect to regional and seasonal climate variability. With this new evidence, the solar wind related particle effects in the atmosphere are now gaining increasing attention. These effects will soon be included in the next coupled model inter comparison project (CMIP6) as an additional solar related climate effect. This emphasizes the relevance of this thesis.
342

Vývojové trendy letecké dopravy mezi člůenskými státy EU a severoamerickým kontinentem / The perspectives of air transport between EU member states and North America

Veverka, Jakub January 2009 (has links)
The final thesis analyzes the actual situation of air transport in North America and the EU. New Open skies treaty signed by EU and USA (also EU and Canada) is the objective of the final thesis. An other goal is its influence on transatlantic flights. Moreover the final thesis treats of the allocation of the airport's slots and the actual safety situation as well. Finally there is a small part about alternative jet fuels and the perspectives of air freight transport.
343

Role of Small States in International Relations: Comparative Analysis of the Czech Republic and Israel / Role malých států v mezinárodních vztazích: Komparativní analýza České republiky a Izraele

Hlavsová, Aneta January 2014 (has links)
This study is titled Role of Small States in International Relations: Comparative Analysis of the Czech Republic and Israel and its main purpose is to analyze a typical small state's behavior in the international arena on the examples of the Czech and Israeli foreign policy. It is divided into four respective sections -- a theoretical framework, historical background, and the two case studies, and it strives to answer a foundational question whether the Czech Republic and Israel can be considered small players in international relations based on the theoretical definition of the notion of a small state as well as the countries' current foreign policy approaches and tools.
344

Role Spojených států amerických v NATO: změny po 11. září 2001 za vlády prezidenta G. W. Bushe / The Role of the US in NATO: How Did It Change after 9/11 under Bush Administration

Štverková, Iva January 2017 (has links)
The goal of this thesis is to examine president Bush's policy after 9/11 and its implications for the North Atlantic Treaty Organization. The shock of 9/11 attacks resulted in "war mentality" manifesting itself in the pressure of the public and media for swift radical actions. This resulted in ad hoc decisions taken without proper analyses and consideration of consequences. After 9/11, Bush Administration used black-and-white rhetoric and simplified the war on terror into war between good and evil. The U.S. under Bush did not consider international institutions to play significant role in international politics and preferred bilateral cooperation. By omitting the Alliance, Washing, however, undermined NATO. Europe was sympathetic to the U.S. and proclaimed its support for Washington since day one but European NATO members and the U.S. had different threat perception regarding Iraq, and could not agree on a common solution. The actions taken by Americans in Afghanistan and Iraq and the reluctance of European allies in supporting the U.S. war against terrorism resulted in escalation of relations in the Alliance. As the U.S. headed toward engagement in two conflicts, it increasingly appreciated the value of NATO. On the other hand, Europe never forgot that the United States is its main ally. Most...
345

Národní identita a její promítání do diskuse o vstupu Bosny a Herzegoviny do Severoatlantické alliance / Reflection of National Identities in Bosnia and Herzegovina in the Discussion of NATO Membership

Fajtová, Magdaléna January 2020 (has links)
Diploma thesis "Reflection of National Identities in Bosnia and Herzegovina in the Discussion of NATO Membership" is a discourse analysis focusing on the socio-political environment in Bosnia and Herzegovina in the perspective of discussion over possible accession to the North Atlantic Treaty Organisation. The first part of the thesis begins by an overview of the history of NATO engagement in the conflicts in the former Yugoslavia, followed by a summary of current NATO relations with the countries of Western Balkans, specifically with Bosnia and Herzegovina. Special regard is given to national identities and their role in the conduct of the country's foreign policy. The second part of the thesis is dedicated to examining the current political debate. It seeks to understand how national identity shapes the discussion over the accession to the organisation. Specifically, through discourse analysis, it aims to identify the tools employed in the political debate and the impact it has on the overall political environment of the country.
346

A Bridge between Short-Range and Seasonal Forecasts: Data-Based First Passage Time Prediction in Temperatures

Wulffen, Anja von 25 January 2013 (has links)
Current conventional weather forecasts are based on high-dimensional numerical models. They are usually only skillful up to a maximum lead time of around 7 days due to the chaotic nature of the climate dynamics and the related exponential growth of model and data initialisation errors. Even the fully detailed medium-range predictions made for instance at the European Centre for Medium-Range Weather Forecasts do not exceed lead times of 14 days, while even longer-range predictions are limited to time-averaged forecast outputs only. Many sectors would profit significantly from accurate forecasts on seasonal time scales without needing the wealth of details a full dynamical model can deliver. In this thesis, we aim to study the potential of a much cheaper data-based statistical approach to provide predictions of comparable or even better skill up to seasonal lead times, using as an examplary forecast target the time until the next occurrence of frost. To this end, we first analyse the properties of the temperature anomaly time series obtained from measured data by subtracting a sinusoidal seasonal cycle, as well as the distribution properties of the first passage times to frost. The possibility of generating additional temperature anomaly data with the same properties by using very simple autoregressive model processes to potentially reduce the statistical fluctuations in our analysis is investigated and ultimately rejected. In a next step, we study the potential for predictability using only conditional first passage time distributions derived from the temperature anomaly time series and confirm a significant dependence of the distributions on the initial conditions. After this preliminary analysis, we issue data-based out-of-sample forecasts for three different prediction targets: The specific date of first frost, the probability of observing frost before summer for forecasts issued in spring, and the full probability distribution of the first passage times to frost. We then study the possibility of improving the forecast quality first by enhancing the stationarity of the temperature anomaly time series and then by adding as an additional input variable the state of the North Atlantic Oscillation on the date the predictions are issued. We are able to obtain significant forecast skill up to seasonal lead times when comparing our results to an unskilled reference forecast. A first comparison between the data-based forecasts and corresponding predictions gathered from a dynamical weather model, necessarily using a lead time of only up to 15 days, shows that our simple statistical schemes are only outperformed (and then only slightly) if further statistical post-processing is applied to the model output. / Aktuelle Wetterprognosen werden mit Hilfe von hochdimensionalen, numerischen Modellen generiert. Durch die dem Klima zugrunde liegende chaotische Dynamik wachsen Modellfehler und Ungenauigkeiten in der Modellinitialisierung exponentiell an, sodass Vorhersagen mit signifikanter Güte üblicherweise nur für eine Vorlaufzeit von maximal sieben Tagen möglich sind. Selbst die detaillierten Prognosen des Europäischen Zentrums für mittelfristige Wettervorhersagen gehen nicht über eine Vorlaufzeit von 14 Tagen hinaus, während noch längerfristigere Vorhersagen auf zeitgemittelte Größen beschränkt sind. Viele Branchen würden signifikant von akkuraten Vorhersagen auf saisonalen Zeitskalen pro-fitieren, ohne das ganze Ausmaß an Details zu benötigen, das von einem vollständigen dynamischen Modell geliefert werden kann. In dieser Dissertation beabsichtigen wir, am Beispiel einer Vorhersage der Zeitdauer bis zum nächsten Eintreten von Frost zu untersuchen, inwieweit deutlich kostengünstigere, datenbasierte statistische Verfahren Prognosen von gleicher oder sogar besserer Güte auf bis zu saisonalen Zeitskalen liefern können. Dazu analysieren wir zunächst die Eigenschaften der Zeitreihe der Temperaturanomalien, die aus den Messdaten durch das Subtrahieren eines sinusförmigen Jahresganges erhalten werden, sowie die Charakteristiken der Wahrscheinlichkeitsverteilungen der Zeitdauer bis zum nächsten Eintreten von Frost. Die Möglichkeit, durch einen einfachen autoregressiven Modellprozess zusätzliche Datenpunkte gleicher statistischer Eigenschaften wie der Temperaturanomalien zu generieren, um die statistischen Fluktuationen in der Analyse zu reduzieren, wird untersucht und letztendlich verworfen. Im nächsten Schritt analysieren wir das Vorhersagepotential, wenn ausschließlich aus den Temperaturanomalien gewonnene bedingte Wahrscheinlichkeitsverteilungen der Wartezeit bis zum nächsten Frost verwendet werden, und können eine signifikante Abhängigkeit der Verteilungen von den Anfangsbedingungen nachweisen. Nach dieser einleitenden Untersuchung erstellen wir datenbasierte Prognosen für drei verschiedene Vorhersagegrößen: Das konkrete Datum, an dem es das nächste Mal Frost geben wird; die Wahrscheinlichkeit, noch vor dem Sommer Frost zu beobachten, wenn die Vorhersagen im Frühjahr ausgegeben werden; und die volle Wahrscheinlichkeitsverteilung der Zeitdauer bis zum nächsten Eintreten von Frost. Anschließend untersuchen wir die Möglichkeit, die Vorhersagegüte weiter zu erhöhen - zunächst durch eine Verbesserung der Stationarität der Temperaturanomalien und dann durch die zusätzliche Berücksichtigung der Nordatlantischen Oszillation als einer zweiten, den Anfangszustand charakterisierenden Variablen im Vorhersageschema. Wir sind in der Lage, im Vergleich mit einem naiven Referenzvorhersageschema eine signifikante Verbesserung der Vorhersagegüte auch auf saisonalen Zeitskalen zu erreichen. Ein erster Vergleich zwischen den datenbasierten Vorhersagen und entsprechenden, aus den dynamischen Wettermodellen gewonnenen Prognosen, der sich notwendigerweise auf eine Vorlaufzeit der Vorhersagen von lediglich 15 Tagen beschränkt, zeigt, dass letztere unsere simplen statistischen Vorhersageschemata nur schlagen (und zwar knapp), wenn der Modelloutput noch einer statistischen Nachbearbeitung unterzogen wird.
347

Dynamika bezpečnostních vztahů Polska a USA: motivace spolupráce a současný vývoj / The dynamics of Poland-U.S. security relations: motivation for cooperation and current developments

Kučová, Markéta January 2021 (has links)
The subject of this diploma thesis is the topic of Poland-United States bilateral relations, the form of which results, among other things, from the geographical location and historical experience of Poland. This bilateral cooperation has a major impact on events in the region, making it a very relevant topic to explore in the light of current developments on the international scene. The work is conducted in the form of a case study and its purpose is to analyse the dynamics of Poland-United States cooperation, while the basic premise of the research is the asymmetric form of Polish-U.S. bilateral relations. The aim is to point out that relations between Warsaw and Washington are, by their development and current form, based on consensus rather than coercion from the position of a stronger partner. Glenn H. Snyder's alliance security dilemma is used in this work to analyse the dynamics, too. Due to the conceptualization of strategic culture as a context of strategic behaviour, the work also provides a relatively detailed insight into Polish strategic culture, which serves as a tool for better understanding of Polish foreign policy, security priorities and thus motivation to maintain significant relations with the United States. It is precisely the form of these relations that opens the opportunity...
348

Integrace zemí Visegrádské skupiny do EU a NATO. Spolupráce či samostatný postup? / Integration of the Visegrad Group Countries into the EU and NATO. Cooperation or Individual Approach?

Brychta, Martin January 2011 (has links)
Graduation thesis tries to explore, if the Visegrad Group Countries, i.e. the Czech Republic, Hungary, Poland and Slovakia cooperated together during their effort to acces the North Atlantic Treaty Organisation and the European Union. The thesis is divided into four parts. First part analyses the first steps of Visegrad Cooperation, second part describes the integration process into NATO. The third part is related to the integration with EU. The last part of the thesis sketches the continuation of Visegrad cooperation after accession into EU in 2004. The theory of international regimes was chosen as a theoretical approach to Visegrad Cooperation. The thesis desribes the course of integration process and different forms of cooperation.
349

Utilisation de l’habitat et pressions anthropiques sur une population de rorquals à bosse (Megaptera novaeangliae) de Guadeloupe par suivi terrestre

Proulx, Bruno 10 1900 (has links)
Le sanctuaire Agoa est une aire marine protégée dans la zone économique exclusive (ZEE) des Antilles françaises qui fut créée en 2010 pour la conservation des mammifères marins et de leurs habitats. Il est connu que le rorqual à bosse fréquente les eaux des Antilles de décembre à mai pour la reproduction et la mise bas. Par contre, peu d’information existe sur l’abondance, le comportement, la distribution et les pressions anthropiques sur cette espèce aux Antilles et encore moins dans le sanctuaire. Cette maîtrise s’intéresse principalement à connaître cette espèce dans un secteur précis de cette aire marine et les liens qu’elle entretient avec certains utilisateurs humains de son habitat. Le tout vise à informer les intervenants en place, autant institutionnels qu’utilisateurs, vers une mise en place de mesures de conservation adaptées. Un suivi terrestre hivernal de plus de 300 heures, en 2012 et 2013, a permis de déterminer l’utilisation de l’habitat et les pressions anthropiques sur une population de rorquals à bosse fréquentant le sud de la péninsule de la Pointe-des-Châteaux en Guadeloupe. Il s’agit du premier suivi terrestre de cette espèce aux Antilles françaises et un des premiers dans l'arc caribéen. La zone d’étude couvre environ 264 km2 et serait une des zones les plus fréquentées de l’archipel guadeloupéen par l’espèce. À l’aide d’un théodolite, la trajectoire de 107 groupes différents (137,8 heures, 699 remontées) a été décrite. Les résultats montrent que la zone d’étude est principalement fréquentée en mars et avril, avec une abondance maximale au début du mois d’avril. La forte présence de baleineaux, particulièrement au mois de mars, pousse à croire que cette zone est utilisée comme pouponnière. Le comportement n’est pas aléatoire dans la zone d’étude et les trajectoires convergent vers certaines zones ayant possiblement un lien avec la bathymétrie. De plus, la zone marine à proximité de la Pointe-des-Châteaux pourrait potentiellement être un lieu de convergence des groupes. Ceux-ci se déplacent à vitesse réduite en direction ENE en général, à l’exception des femelles accompagnées de baleineaux qui prennent une orientation tout autre, c’est-à-dire vers le ONO, et ce à plus grande vitesse. Bien que la pression d’observation soit considérée comme modérée, une forte proportion des remontées se trouve dans les corridors de navigation présents dans la zone d’étude. De plus, le corridor de navigation des navettes entre Saint-François et La Désirade comporte le plus grand risque relatif de collision mortelle. Une réduction de vitesse des embarcations fréquentant le corridor des navettes diminuerait significativement le risque de collision mortelle. Ces pistes de réflexion mèneront sans doute à d’autres études plus poussées afin de continuer à en apprendre sur l’écologie de cette espèce fascinante. / The Agoa sanctuary, a marine protected area (MPO) covering the exclusive economic zone (EEZ) in the French Caribbean, was created in 2010 to protect marine mammals and their habitats. It is known that the Caribbean islands are used from December to May by humpback whales (Megaptera novaeangliae) as a reproductive area. However, sparse information exists on the abundance, the behaviour, the distribution and the anthropogenic pressures on this species in the Caribbean and even less in the sanctuary. This thesis focuses on increasing scientific knowledge about this species’ use of a part of the Agoa Sanctuary and their interactions with human users of the MPO. Such knowledge may inform stakeholders’ (institutional and individual) decision-making towards implementation of appropriate conservation measures. A land-based survey of more than 300 hours, in 2012 and 2013, was carried out to determine the habitat use of, and anthropogenic pressures on, a population of humpback whales frequenting the surrounding water of the Pointe-des-Châteaux peninsula in Guadeloupe. This is the first land-based survey of this species in the French West Indies and one of the first in the Caribbean. The study area of approximately 264 square kilometres is one of the most visited areas by this species in the Guadeloupe archipelago. Using a theodolite, 107 trajectories (i.e. groups of whales) were recorded, representing 137.8 hours and 699 surfacings. Results show that the abundance was higher in March and April with a peak in the first week of April. The high proportion of calves in this population, mainly in March, suggest that the study zone is a nursing area. Overall movement patterns are not random and may possibly be dictated by the bathymetry. Furthermore, trajectories seem to converge close to the Pointe-des-Châteaux. The average movement is slow and oriented in the same direction as the dominant current to the west of the Pointe-des-Châteaux (i.e. ENE), except for mother and calf groups that swim faster in the opposite direction (i.e. WNW). Even if the anthropogenic pressure may be consided as moderate, a high proportion of surfacing is located in some of the main maritime traffic corridors. In addition, the shuttle corridor between Saint-Francois and Désirade island has the greatest relative risk of fatal collision. A reduced speed for the shuttle corridor would lower significantly the collision risk. These findings may lead to more extensive studies to better understand the ecology of this fascinating species.
350

NATO continuity and change : the Atlantic Alliance as an institution, organization and force by reference to Articles 4, 5, and 6 of the Washington Treaty

Branikas, Spyros 12 1900 (has links)
Approved for public release; distribution in unlimited. / This thesis examines the evolution of NATO as an institution in the International System by reference to Articles 4, 5 and 6 of the Washington Treaty of 1949. Initially, the thesis considers NATO from an international relations perspective. It then proceeds to examine the institutional evolutionary process of the Alliance since its inception and implementation in 1949. Furthermore, it explores the significance and the meaning of the aforementioned Articles. This thesis utilizes the case study method and refers to four distinct events that have shaped allied policies and strategies: the Suez Crisis of 1956, the establishment of the politico-military consultation process, the Yom Kippur War (1973), and the end of the Cold War (1989-1991). It also examines the allied policies after the events of September 11, 2001. Moreover, it identifies a general pattern of events pertinent to crisis creation inside NATO when the organization is facing a defense issue outside the Euro-Atlantic area. Finally, the thesis concludes that NATO is more than an ordinary military Alliance, as advocated by its longevity, agility and adaptability, which allows the Alliance to maintain a central position in the International System as a robust politico-military organization. / Lieutenant Commander, Hellenic Navy

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