924 resultados para Discrete global grid system


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The highly dynamic nature of some sandy shores with continuous morphological changes require the development of efficient and accurate methodological strategies for coastal hazard assessment and morphodynamic characterisation. During the past decades, the general methodological approach for the establishment of coastal monitoring programmes was based on photogrammetry or classical geodetic techniques. With the advent of new geodetic techniques, space-based and airborne-based, new methodologies were introduced in coastal monitoring programmes. This paper describes the development of a monitoring prototype that is based on the use of global positioning system (GPS). The prototype has a GPS multiantenna mounted on a fast surveying platform, a land vehicle appropriate for driving in the sand (four-wheel quad). This system was conceived to perform a network of shore profiles in sandy shores stretches (subaerial beach) that extend for several kilometres from which high-precision digital elevation models can be generated. An analysis of the accuracy and precision of some differential GPS kinematic methodologies is presented. The development of an adequate survey methodology is the first step in morphodynamic shore characterisation or in coastal hazard assessment. The sample method and the computational interpolation procedures are important steps for producing reliable three-dimensional surface maps that are real as possible. The quality of several interpolation methods used to generate grids was tested in areas where there were data gaps. The results obtained allow us to conclude that with the developed survey methodology, it is possible to Survey sandy shores stretches, under spatial scales of kilometers, with a vertical accuracy of greater than 0.10 m in the final digital elevation models.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Ten GPS-Met stations were installed in northwest Mexico from June - September 2013. Each station included a Trimble NetR9 GPS receiver for PWV and a Vaisala WXT520 surface meteorological package measuring wind speed and direction, air temperature, humidity, pressure and precipitation. The geographic location, elevation and data period for each station are provided in Serra et al. (2016). The GPS receiver at Rayon failed on July 16, 21 days after installation, thus these data are not included in the archive but are available upon request (yserra@uw.edu). Data include 1-min surface meteorological variables, while the GPS PWV is calculated at 5-min intervals. A full description of the experiment can be found in Serra et al., 2016: Bull. Am. Meteor. Soc., doi: 10.1175/BAMS-D-14-00250.1.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Anualmente, realizam-se no país inúmeras iniciativas de Todo-Terreno Turístico (TTT) onde são automaticamente registadas as coordenadas de Global Positioning System (GPS) por aplicações de dispositivos móveis. Este tipo de informação pode ser utilizada, quer para fins de divulgação turística, quer por outro tipo de entidades que necessitem de circular nesses caminhos rurais, tipicamente no meio da montanha. Entre outras, são registadas a posição, velocidade e altitude do veículo, o que permite obter informações relevantes, tais como, se o percurso se encontra transitável ou qual a velocidade recomendada. Por exemplo, durante os combates a incêndios, os bombeiros e proteção civil poderão saber se estes percursos são utilizáveis no planeamento dos combates a incêndios com reduzida probabilidade de complicações relativa ao acesso dos veículos, melhorando assim o tempo de resposta. O presente documento discute como poderá ser concebida uma aplicação web mapping, de código aberto, que permita a partilha, utilização e valorização de dados relativos aos percursos todo-terreno dos praticantes de TTT. O presente documento descreve como a aplicação desenvolvida no âmbito da dissertação de mestrado permite selecionar e ordenar possíveis trajetos que incluem os trajetos de TTT, apresentando as caraterísticas do terreno de modo a auxiliar a tomada de decisão por membros das corporações de Bombeiros. Será igualmente apresentada a interface atual da aplicação que inclui um mapa dinâmico e um gestor de pontos de referência.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The aim of this thesis was threefold, firstly, to compare current player tracking technology in a single game of soccer. Secondly, to investigate the running requirements of elite women’s soccer, in particular the use and application of athlete tracking devices. Finally, how can game style be quantified and defined. Study One compared four different match analysis systems commonly used in both research and applied settings: video-based time-motion analysis, a semi-automated multiple camera based system, and two commercially available Global Positioning System (GPS) based player tracking systems at 1 Hertz (Hz) and 5 Hz respectively. A comparison was made between each of the systems when recording the same game. Total distance covered during the match for the four systems ranged from 10 830 ± 770 m (semi-automated multiple camera based system) to 9 510 ± 740m (video-based time-motion analysis). At running speeds categorised as high-intensity running (>15 km⋅h-1), the semi-automated multiple camera based system reported the highest distance of 2 650 ± 530 m with video-based time-motion analysis reporting the least amount of distance covered with 1 610 ± 370 m. At speeds considered to be sprinting (>20 km⋅h-1), the video-based time-motion analysis reported the highest value (420 ± 170 m) and 1 Hz GPS units the lowest value (230 ± 160 m). These results demonstrate there are differences in the determination of the absolute distances, and that comparison of results between match analysis systems should be made with caution. Currently, there is no criterion measure for these match analysis methods and as such it was not possible to determine if one system was more accurate than another. Study Two provided an opportunity to apply player-tracking technology (GPS) to measure activity profiles and determine the physical demands of Australian international level women soccer players. In four international women’s soccer games, data was collected on a total of 15 Australian women soccer players using a 5 Hz GPS based athlete tracking device. Results indicated that Australian women soccer players covered 9 140 ± 1 030 m during 90 min of play. The total distance covered by Australian women was less than the 10 300 m reportedly covered by female soccer players in the Danish First Division. However, there was no apparent difference in the estimated "#$%&', as measured by multi-stage shuttle tests, between these studies. This study suggests that contextual information, including the “game style” of both the team and opposition may influence physical performance in games. Study Three examined the effect the level of the opposition had on the physical output of Australian women soccer players. In total, 58 game files from 5 Hz athlete-tracking devices from 13 international matches were collected. These files were analysed to examine relationships between physical demands, represented by total distance covered, high intensity running (HIR) and distances covered sprinting, and the level of the opposition, as represented by the Fédération Internationale de Football Association (FIFA) ranking at the time of the match. Higher-ranking opponents elicited less high-speed running and greater low-speed activity compared to playing teams of similar or lower ranking. The results are important to coaches and practitioners in the preparation of players for international competition, and showed that the differing physical demands required were dependent on the level of the opponents. The results also highlighted the need for continued research in the area of integrating contextual information in team sports and demonstrated that soccer can be described as having dynamic and interactive systems. The influence of playing strategy, tactics and subsequently the overall game style was highlighted as playing a significant part in the physical demands of the players. Study Four explored the concept of game style in field sports such as soccer. The aim of this study was to provide an applied framework with suggested metrics for use by coaches, media, practitioners and sports scientists. Based on the findings of Studies 1- 3 and a systematic review of the relevant literature, a theoretical framework was developed to better understand how a team’s game style could be quantified. Soccer games can be broken into key moments of play, and for each of these moments we categorised metrics that provide insight to success or otherwise, to help quantify and measure different methods of playing styles. This study highlights that to date, there had been no clear definition of game style in team sports and as such a novel definition of game style is proposed that can be used by coaches, sport scientists, performance analysts, media and general public. Studies 1-3 outline four common methods of measuring the physical demands in soccer: video based time motion analysis, GPS at 1 Hz and at 5 Hz and semiautomated multiple camera based systems. As there are no semi-automated multiple camera based systems available in Australia, primarily due to cost and logistical reasons, GPS is widely accepted for use in team sports in tracking player movements in training and competition environments. This research identified that, although there are some limitations, GPS player-tracking technology may be a valuable tool in assessing running demands in soccer players and subsequently contribute to our understanding of game style. The results of the research undertaken also reinforce the differences between methods used to analyse player movement patterns in field sports such as soccer and demonstrate that the results from different systems such as GPS based athlete tracking devices and semi-automated multiple camera based systems cannot be used interchangeably. Indeed, the magnitude of measurement differences between methods suggests that significant measurement error is evident. This was apparent even when the same technologies are used which measure at different sampling rates, such as GPS systems using either 1 Hz or 5 Hz frequencies of measurement. It was also recognised that other factors influence how team sport athletes behave within an interactive system. These factors included the strength of the opposition and their style of play. In turn, these can impact the physical demands of players that change from game to game, and even within games depending on these contextual features. Finally, the concept of what is game style and how it might be measured was examined. Game style was defined as "the characteristic playing pattern demonstrated by a team during games. It will be regularly repeated in specific situational contexts such that measurement of variables reflecting game style will be relatively stable. Variables of importance are player and ball movements, interaction of players, and will generally involve elements of speed, time and space (location)".

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The coastal districts, as an intersection of two perfectly different ecosystems of dry land and sea, is one of the most complicated and the richest natural system on earth. Considering these areas are constantly exposed to aggregation of water pollutants and also consequence resulting from construction and development activities, they are very vulnerable. Therefore, "sensitive Coastal areas" has become a common word in the related subjects to marine environment recently. The said title relates to the areas of the coastal lines which are vulnerable to the natural condition or human actions because of ecological, social, economic, educational and research importance, also they need particular supports. The southern coasts of Caspian Sea, In Iran prominent samples are of these sensitive areas which their environment are exposed to demolition and destruction intensely, due to increasing and uncontrolled development. The first stage of protecting and managing the coastal areas is identifying sensitive Coastal areas and broadening the Coasts. In this survey, we attempted to examine a definite area in the southern coasts of Caspian Sea. In Iran, by profiting from the world experiences and concluded researches in Iran especially the concluded studies by marine environment office and the Environment protection organization on the subject of determination criteria of the sensitive ecological districts. For this purpose (In Gilan Province) Boujagh national park district which is located in the mouth of sefidroud river and also is possessed of the special ecological and environmental features and distinctions. In this survey, first they said district is divided proportionally on the basis of using a grid system in order to identify the sensitive ecological districts and broaden the coast, and then the desired indices have been determined and scored by numeral valuation method in each unit and then analysis has been done by using of the geography information system (GIS) and final has estimated economic valuation of sensitive ecological areas that is presented in this essay.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Augmented Reality (AR) applications often require knowledge of the user’s position in some global coordinate system in order to draw the augmented content to its correct position on the screen. The most common method for coarse positioning is the Global Positioning System (GPS). One of the advantages of GPS is that GPS receivers can be found in almost every modern mobile device. This research was conducted in order to determine the accuracies of different GPS receivers. The tests included seven consumer-grade tablets, three external GPS modules and one professional-grade GPS receiver. All of the devices were tested with both static and mobile measurements. It was concluded that even the cheaper external GPS receivers were notably more accurate than the GPS receivers of the tested tablets. The absolute accuracy of the tablets is difficult to determine from the test results, since the results vary by a large margin between different measurements. The accuracy of the tested tablets in static measurements were between 0.30 meters and 13.75 meters.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Long-term monitoring of data of ambient mercury (Hg) on a global scale to assess its emission, transport, atmospheric chemistry, and deposition processes is vital to understanding the impact of Hg pollution on the environment. The Global Mercury Observation System (GMOS) project was funded by the European Commission (http://www.gmos.eu) and started in November 2010 with the overall goal to develop a coordinated global observing system to monitor Hg on a global scale, including a large network of ground-based monitoring stations, ad hoc periodic oceanographic cruises and measurement flights in the lower and upper troposphere as well as in the lower stratosphere. To date, more than 40 ground-based monitoring sites constitute the global network covering many regions where little to no observational data were available before GMOS. This work presents atmospheric Hg concentrations recorded worldwide in the framework of the GMOS project (2010–2015), analyzing Hg measurement results in terms of temporal trends, seasonality and comparability within the network. Major findings highlighted in this paper include a clear gradient of Hg concentrations between the Northern and Southern hemispheres, confirming that the gradient observed is mostly driven by local and regional sources, which can be anthropogenic, natural or a combination of both.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Resumen La intensificación de la crisis a nivel global, luego de la bancarrota de Lehman Brothers en septiembre del 2008, ha provocado que el actual entorno económico y financiero sea complicado para la economía mundial, el sector financiero a nivel global y para los bancos centrales. La actual crisis deriva de muchas causas; no obstante las principales son tres: primero, aspectos macroeconómicos; segundo, la inadecuada regulación de los entes encargados, y tercero, los reguladores estimularon el rápido crecimiento de los derivados en el mercado OTC. Abstract The amplification of the global financial crisis, following the bankruptcy of Lehman Brothers in September 2008, has made the present economic and financial environment a not easy time for the world economy, the global financial system and for central banks. There are many causes from the recent financial crisis. Main could be three. First, there were macroeconomic components. Second, the inadequate oversight/regulation provided by financial market regulators. And third, federal regulators have actively encouraged the rapid growth of over-the-counter (OTC) derivatives and securities by all types of financial institutions.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

vulnerabilidad a deslizamientos ubicado en el Cerro Tamuga del cantón Paute, provincia del Azuay, la metodología empleada consiste en utilizar la técnica DGPS (Differential Global Positioning System), la misma que incluye el uso simultaneo de dos o más receptores, el método de medida empleado para las observaciones DGPS es el estático rápido con un tiempo de medida de diez minutos para cada hito, los resultados fueron comparados con mediciones realizadas con estación total, para lo que se aplicó el método de medida y cálculo de triangulación; que consiste en observar desde dos bases diferentes al mismo hito para realizar la triangulación y procesamiento de los datos. Durante la etapa de muestreo se realizó 20 campañas de medición con técnicas DGPS, monitoreando un total de 14 hitos, con técnicas convencionales (Topográficas) se realizó 7 campañas y se monitoreó 14 hitos. De estos datos se obtiene la diferencia entre la última y la primera medición tanto para valores de X, Y y Z, y por tanto se obtiene la variación de precisión para los dos métodos de medición (DGPS y Estación Total). Con los resultados (∆X, ∆Y, ∆Z) se realiza el análisis de la direccionalidad de los vectores de desplazamiento mediante la diferencia entre el promedio de todas las mediciones con el primer punto medido. Los resultados DGPS presentan menor variabilidad de los datos, por lo que se sugiere emplear esta técnica en la medición de desplazamiento en extensiones grandes. Con relación al caso de estudio del Cerro Tamuga, se determinó que mediante las mediciones con DGPS, éste no presenta movimientos, pero se deben continuar las campañas de monitoreo para analizar la situación a largo plazo.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Many studies suggest that migratory birds are expected to travel more quickly during spring, when they are en route to the breeding grounds, in order to ensure a high-quality territory. Using data recorded by means of Global Positioning System satellite tags, we analysed at three temporal scales (hourly, daily and overall journey) seasonal differences in migratory performance of the booted eagle (Aquila pennata), a soaring raptor migrating between Europe and tropical Africa, taking into account environmental conditions such as wind, thermal uplift and day length. Unexpectedly, booted eagles showed higher travel rates (hourly speed, daily distance, overall migration speed and overall straightness) during autumn, even controlling for abiotic factors, probably thanks to higher hourly speeds, more straight routes and less non-travelling days during autumn. Tailwinds were the main environmental factor affecting daily distance. During spring, booted eagles migrated more quickly when flying over the Sahara desert. Our results raise new questions about which ecological and behavioural reasons promote such unexpected faster speeds in autumn and not during spring and how events occurring in very different regions can affect migratory performance, interacting with landscape characteristics, weather conditions and flight behaviour.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Use of the Global Positioning System (GPS) for quantifying athletic performance is common in many team sports. The effect of running velocity on measurement validity is well established, but the influence of rapid directional change is not well understood in team sport applications. This effect was systematically evaluated using multidirectional and curvilinear adaptations of a validated soccer simulation protocol that maintained identical velocity profiles. Team sport athletes completed 90 min trials of the Loughborough Intermittent Shuttle-running Test movement pattern on curvilinear, and multidirectional shuttle running tracks while wearing a 5 Hz (with interpolated 15 Hz output) GPS device. Reference total distance (13 200 m) was systematically over- and underestimated during curvilinear (2.61±0.80%) and shuttle (-3.17±2.46%) trials, respectively. Within-epoch measurement uncertainty dispersion was widest during the shuttle trial, particularly during the jog and run phases. Relative measurement reliability was excellent during both trials (Curvilinear r = 1.00, slope = 1.03, ICC = 1.00; Shuttle r = 0.99, slope = 0.97, ICC = 0.99). Absolute measurement reliability was superior during the curvilinear trial (Curvilinear SEM = 0 m, CV = 2.16%, LOA ± 223 m; Shuttle SEM = 119 m, CV = 2.44%, LOA ± 453 m). Rapid directional change degrades the accuracy and absolute reliability of GPS distance measurement, and caution is recommended when using GPS to quantify rapid multidirectional movement patterns.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Here, we show how seasonal changes in animal density drive strategic shifts in the activities of wildlife-watching operators. These shifts result in high viewing intensity when animal densities are low, highlighting the need for modifications to existing wildlife-watching guidelines. We used the endangered loggerhead sea turtle Caretta caretta as a model species that exhibits staggered departure from an important breeding area (Zakynthos, Greece, Mediterranean) over a 2-month period (July to August) when tourism is at a peak, to investigate changes in wildlife-watching strategies, zoning effectiveness and voluntary guideline compliance over time. We used a combination of direct land-based observations, global positioning system tracking (of wildlife-watching vessels and turtles) and models. The modelled number of turtles present in the breeding area decreased from >200 in July to <50 in August, while the intensity of turtle-viewing increased from a mean 1.5 to 6.1 wildlife-watching vessels per turtle-viewing event (i.e. concurrent and consecutive vessels observing a single turtle) over the same period, respectively. During this period, the wildlife-watching strategy changed and compliance to guidelines reduced (exacerbated by recreational vessels). However, wildlife-watching activity was limited to a highly restricted 0.95-km2 nearshore area, overlapping with just 9.5% of the core habitat area used by turtles. Our results have broad implications (whale watching etc.) by showing the importance of taking the number of animals available for viewing into consideration when assessing wildlife-watching activity and when designing viewing guidelines, particularly for populations where numbers noticeably fluctuate.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

How to enhance the communication efficiency and quality on vehicular networks is one critical important issue. While with the larger and larger scale of vehicular networks in dense cities, the real-world datasets show that the vehicular networks essentially belong to the complex network model. Meanwhile, the extensive research on complex networks has shown that the complex network theory can both provide an accurate network illustration model and further make great contributions to the network design, optimization and management. In this paper, we start with analyzing characteristics of a taxi GPS dataset and then establishing the vehicular-to-infrastructure, vehicle-to-vehicle and the hybrid communication model, respectively. Moreover, we propose a clustering algorithm for station selection, a traffic allocation optimization model and an information source selection model based on the communication performances and complex network theory.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This thesis presents a load sharing method applied in a distributed micro grid system. The goal of this method is to balance the state-of-charge (SoC) of each parallel connected battery and make it possible to detect the average SoC of the system by measuring bus voltage for all connected modules. In this method the reference voltage for each battery converter is adjusted by adding a proportional SoC factor. Under such setting the battery with a higher SoC will output more power, whereas the one with lower SoC gives out less. Therefore the higher SoC battery will use its energy faster than the lower ones, and eventually the SoC and output power of each battery will converge. And because the reference voltage is related to SoC status, the information of the average SoC in this system could be shared for all modules by measuring bus voltage. The SoC balancing speed is related to the SoC droop factors. This SoC-based load sharing control system is analyzed in feasibility and stability. Simulations in MATLAB/Simulink are presented, which indicate that this control scheme could balance the battery SoCs as predicted. The observation of SoC sharing through bus voltage was validated in both software simulation and hardware experiments. It could be of use to non-communicated distributed power system in load shedding and power planning.