• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 96
  • 44
  • 16
  • 12
  • 5
  • 5
  • 4
  • 3
  • 3
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 222
  • 222
  • 32
  • 30
  • 25
  • 25
  • 23
  • 16
  • 14
  • 14
  • 14
  • 14
  • 11
  • 11
  • 11
  • 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.
171

Autovlaky v mezinárodní železniční přepravě / Car trains in International Rail Transport

Nejedlý, Vojtěch January 2012 (has links)
This thesis is focused on the segment of motorail services in the international long-distance passenger rail transport. It presents this service in the Czech Republic and also in the context of international passenger rail transport. The practical part is aimed at analyzing the potential and competitiveness of this service compared to road individual car transport and at exploring options of this product for practical usage by the final customer in choosing an appropriate service or means of transport for long-distance passenger transport in conditions of the Central European market.
172

Koncept design automobilu pro dálkové cestování / Concept design of a Long-Range Car

Baka, Michal January 2020 (has links)
The topic of this diploma thesis is concept design long-range car of future, using electric drive. The main goal is to solve analyzed problems, which are reflected in the conceptual design of the vehicle that meets the ergonomic, technical and visual aspects, all focused in car interior.
173

Solutions évolutives pour les réseaux de communication quantique / Scalable solutions for quantum communication networks

Fedrici, Bruno 13 December 2017 (has links)
Le déploiement de réseaux de communication quantique représente un défi auquel cette thèse apporte des solutions originales. Deux dispositifs très performants sont construits uniquement autour de composants standards de l'optique intégrée et des télécommunications optiques. Le premier correspond à un schéma de synchronisation tout optique sur longue distance à très haute cadence et de précision inégalée pour la communication sécurisée par cryptographie quantique. Le montage expérimental repose sur une configuration de relais quantique mettant en œuvre deux sources indépendantes de paires de photons intriqués dont il faut synchroniser les temps d'émissions. L’idée principale s’appuie sur l’utilisation d’un unique laser télécom picoseconde cadencé à 2.5 GHz afin de générer l’horloge et de pouvoir la distribuer efficacement aux deux sources. Nous démontrons la synchronisation de notre lien relais pour une distance effective séparant les sources de plus de 100 km. Le second dispositif correspond quant à lui à la réalisation d'une expérience de compression à une longueur d'onde des télécommunications réalisée, pour la première fois, de manière entièrement guidée. La lumière comprimée étant une ressource fondamentale dans bon nombre de protocoles d'information quantique, la réalisation de systèmes expérimentaux facilement reconfigurables et compatibles avec les réseaux télécoms fibrés existants représente une étape cruciale en vue du déploiement de dispositifs de communication quantique en régime de variables continues. Enfin, un traitement quantique des effets de gigue temporelle dans les détecteurs de photons 0N/0FF est proposé. Malgré l'importance des systèmes de détection dans les technologies quantiques photoniques émergentes, aucune modélisation quantique de leurs effets de gigue temporelle n'avait été, à notre connaissance, développé jusqu'à présent. / This thesis presents solutions to the challenges of developing quantum communication networks. Two powerful experimental devices have been set up relying only on standard telecom and integrated optical components. The first device corresponds to an all-optical synchronization scheme allowing, with an unprecedented accuracy, quantum key distribution at a high rate over long distances. The experimental scheme relies on two independent entangled photon pair sources that have to be synchronized in their emission time. Our approach is based on using a 2.5 GHz picosecond telecom laser as a master clock to efficiently synchronize the different sources. We demonstrate the synchronization for an effective distance of 100 km between sources. With our second device, we perform a squeezing experiment at telecom wavelengths and this for the first time in a fully guided-wave approach. Squeezed light being a fundamental resource for several quantum information protocols, developing plug-and-play experimental devices that are compatible with already existing telecom fiber networks is of first interest in the perspective of future quantum networks. Finally, we propose a quantum description of timing jitter effects in 0N/0FF detectors. Despite the importance of detection systems in emerging photonic quantum technologies, no quantum description of their timing jitter effects has been proposed so far.
174

Kontrola aktivit partnera na dálku v prostředí nových médií / Monitoring of long distance relationship's partner activity in the context of new media

Plecitá, Pavlína January 2020 (has links)
The text of the thesis deals with controlling, monitoring, tracking and analyzing an individual's online activities by another person and the influence of this Internet behavior on its reflection in reality. The theoretical part deals with relevant issues from the field of ethics, psychology, theory of computer communication and theory of privacy and technological supervision. The practical part is focused on qualitative analysis of behavior of individuals living in long distance relationships and their strategies for using new media as a means to control the activity of their faraway partner.
175

The usage of location based big data and trip planning services for the estimation of a long-distance travel demand model. Predicting the impacts of a new high speed rail corridor

Llorca, Carlos, Ji, Joanna, Molloy, Joseph, Moeckel, Rolf 24 September 2020 (has links)
Travel demand models are a useful tool to assess transportation projects. Within travel demand, long-distance trips represent a significant amount of the total vehicle-kilometers travelled, in contrast to commuting trips. Consequently, they pay a relevant role in the economic, social and environmental impacts of transportation. This paper describes the development of a microscopic long-distance travel demand model for the Province of Ontario (Canada) and analyzes the sensitivity to the implementation of a new high speed rail corridor. Trip generation, destination choice and mode choice models were developed for this research. Multinomial logit models were estimated and calibrated using the Travel Survey for Residents in Canada (TSRC). It was complemented with location-based social network data from Foursquare, improving the description of activities and diverse land uses at the destinations. Level of service of the transit network was defined by downloading trip time, frequency and fare using the planning service Rome2rio. New scenarios were generated to simulate the impacts of a new high speed rail corridor by varying rail travel times, frequencies and fares of the rail services. As a result, a significant increase of rail modal shares was measured, directly proportional to speed and frequency and inversely proportional to price.
176

Dálkové šíření Rumex alpinus / Long distance dispersal of Rumex alpinus

Řičařová, Veronika January 2011 (has links)
Long-distance dispersal of Rumex alpinus was studied in the Giant Mountain in the National Park. The invasion of R. alpinus is there kind of problem. The work builds on a thesis from year 2007 (20007 Červenková), in which was made the model of the invasion of R. alpinus in the area of the Giant Mountain. The measurements of the seeds spread take place at four localities, three of them were for measuring of water dispersal and one was for measuring of winter dispersal. Anemochory was measured using traps in the meadow up to a distance of 50 m. The seeds were dispersed by wind to a distance of 20 meters. Hydrochory was measured using a network's traps in the streams up to 100 m. The largest measured water dispersal was 100 m. Hydrochory therefore proved to be an important factor, which influenced the invasion of R. alpinus. The storms and flood had the great influence on the hydrochory and anemochory. The prediction exponential curves were compiled from the data about the wind dispersal. The curves express the spread to more than a measured distance. The field dispersion curves were compared with theoretical curves, which were used in the model of the invasion from 2007. It turned out that the theoretical curves overestimate the spread of R. alpinus by wind. The dispersion of seeds was underestimated in the...
177

Alternative Drivetrain for Future Freight Trucks

Tsamos, Athanasios January 2020 (has links)
Presently, heavy-duty trucks are responsible for approximately 25% of global CO2 emissions. Although the world seems to incline towards the transport sector's electrification, the electrification of long-range freight trucks is profoundly challenging. The dominant disincentives are the required infrastructure, cost/size of batteries, limited mileage, and long charging sessions. However, despite the efforts to reduce emissions, current trends indicate that these continue to rise, mostly because of the continually increasing freight transit. Regional economies are heavily dependent on the latter. Thus, the imminent depletion of fossil fuels and the emerging environmental issues are disquieting aspects for the sustainability of this crucial sector. This thesis focuses on the possible alternative powertrain/drivetrain solutions for heavy-duty, long-range freight trucks in conjunction with sustainable energy carriers for the transportation sector overall. In terms of viable fuelling alternatives, the following are being reviewed: Electric Power, Bio-Fuels, and Synthetic Fuels, along with their current status, advantages, disadvantages and future prospects. In terms of powertrain/drivetrain alternatives, the following are being theoretically and critically evaluated and compared against a direct drive conventional Diesel engine truck (25.2% wheel efficiency): Battery Electric, Electric powered with overhead cables or underground conductive coils, combined Gas Turbine/Stirling Engine Hybrid Electric in series, combined Diesel engine/Stirling engine Hybrid Electric in series, and Diesel engine Hybrid Electric in series.  It is concluded that the best scenario for future freight trucks, is the use of an electric drivetrain/powertrain in conjunction with overhead powering cables along the highways. However, due to uncertainties in the universal realization of such infrastructure, to ensure uninterrupted transportation of goods, a plausible transitional solution could be the use of a Diesel engine/Stirling engine Hybrid Electric in series technology. This could reduce emissions/consumption by a factor of 2.4 (60% wheel efficiency). For the case of Gas turbine/Stirling engine and Diesel engine (both) Hybrid Electric in-series arrangements, this factor drops to 1.7 and 1.4 (42.9% and 34.3% wheel efficiency), respectively. Furthermore, this can be a clean and sustainable solution if biofuels are employed as the prime energy carriers. Such an approach is future-proof for use with overhead cables, since the suggested powertrain is electric, rendering a freight truck as a very versatile heavy-duty, long-range vehicle. Electro-fuels are not considered as a viable option due to their inefficient formulation, elevated costs, and problematic handling (Hydrogen).
178

Creencias y atribuciones causales de docentes del Nivel Inicial de Lima Metropolitana respecto a la educación a distancia (EAD) a partir de la estrategia multicanal del Ministerio de Educación “Aprendo en casa” / Beliefs and causal attributions of teachers of the preschool level of Metropolitan Lima regarding distance education (DL) from the multi-channel strategy of the Ministry of Education "Aprendo en casa"

Ojeda Rebaza, Martha Gabriela, Paz Castro, Danitza Nicole 08 August 2021 (has links)
El propósito del estudio fue identificar, en docentes de Nivel Inicial de Lima Metropolitana, creencias y atribuciones causales sobre la educación a distancia (EAD) a partir de su experiencia con la estrategia del Ministerio de Educación (Minedu) “Aprendo en casa” (AEC). La indagación se elaboró desde el método cualitativo, con recursos de la teoría fundamentada y la aproximación fenomenológica. En ese marco, se realizaron 5 entrevistas semiestructuradas, con un total de 16 preguntas agrupadas en 5 dimensiones que abordaban la EAD y la estrategia AEC. Los resultados muestran que las docentes consideran que, en la EAD, se desarrollan competencias del Nivel Inicial, aunque de forma limitada. Atribuyen esto a la edad del estudiante, la participación de los padres y el rol del docente. Asimismo, respecto a la formación docente para desenvolverse en EAD, las participantes se consideraban preparadas en aspectos como la capacidad de investigación y el aprendizaje continuo; habilidades obtenidas en la universidad. Sin embargo, frente al manejo de herramientas tecnológicas, afirmaban experimentar ciertas dificultades que superaron con el trabajo colegiado, y algunas orientaciones del Estado o complementarias. Por otro lado, si bien la experiencia con AEC y la EAD ha sido un reto para ellas, manifiestan sentirse satisfechas con su desempeño y con la estrategia. Lo primero ocurre porque perciben que se han comprometido con su trabajo de la misma manera que en la presencialidad. Lo segundo se produce debido a que atribuyen lo oportuno de la estrategia a la organización, a la atención de necesidades de la edad y el contexto, y porque fue desarrollada por especialistas del Minedu. / The purpose of the study was to identify, in teachers of Initial Level of Metropolitan Lima, beliefs and causal attributions about distance education (DL) from their experience with the strategy of the Ministry of Education (Minedu) "Aprendo en casa" (AEC). The inquiry was developed from the qualitative method, with resources from grounded theory and the phenomenological approach. Within this framework, 5 semi-structured interviews were conducted, with a total of 16 questions grouped into 5 dimensions that addressed the DL and the AEC strategy. The results show that the teachers consider that, in the DL, competences of the preschool level are developed, although in a limited way. They attribute this to the age of the student, parental involvement, and the role of the teacher. Likewise, regarding teacher training to function in DL, the participants considered themselves prepared in aspects such as research capacity and continuous learning; skills obtained in college. However, when dealing with technological tools, they claimed to experience certain difficulties that they overcame with collegiate work, and some guidance from the State or complementary. On the other hand, although the experience with AEC and DL has been a challenge for them, they state that they feel satisfied with their performance and with the strategy. The first occurs because they perceive that they have committed to their work in the same way as in person. The second occurs because they attribute the appropriateness of the strategy to the organization, to meeting the needs of age and context, and because it was developed by Minedu specialists. / Trabajo de Suficiencia Profesional
179

Exploring the Impact of Psychological Detachment on Stress and Anxiety in Distance Caregivers of Cancer Patients

Musacchio, Christine Marie 26 January 2021 (has links)
No description available.
180

Work on track! : A train interior design concept to meet contemporary work trends and needs

Abaitua Knight, Alicia M January 2023 (has links)
In a future vision for rail travel, trains will be designed as an activity-based whole space, with different areas for various activities, such as relaxing, socialising or family bonding. My degree project, in collaboration with SJ, proposes a concept carriage dedicated to work, analogous to spending a day at a mobile coworking space. By recognising the new ways of working, this carriage will cater for the needs of different individuals and various types of work and will include private digital meeting spaces, group compartments, collaborative open spaces and cocoon-like seating options in quiet areas. Unlike other modes of transportation, trains allow for passengers to navigate and experience different spaces. By enhancing the use of space and incorporating amenities that improve the user experience, I aim to transform the perception of long train journeys from tedious to exciting and allow a more seamless and efficient way of getting work done while travelling. Ultimately, this degree project encourages sustainable travel through user-centred design.

Page generated in 0.0637 seconds