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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.
601

An Embedded Nonlinear Control Implementation for a Hovering Small Unmanned Aerial System

Althaus, Joseph H. 20 July 2010 (has links)
No description available.
602

DERIVING ACTIVITY PATTERNS FROM INDIVIDUAL TRAVEL DIARY DATA: A SPATIOTEMPORAL DATA MINING APPROACH

Ding, Guoxiang 31 August 2009 (has links)
No description available.
603

Modeling Accelerating Trands of Displacement in Geodetic Time Series

Wang, Jian 13 September 2010 (has links)
No description available.
604

DETECTING MULTIPLE PROTEIN FOLDING TRAJECTORIES AND STRUCTURAL ALIGNMENT

Sun, Hong 15 December 2011 (has links)
No description available.
605

Human-like Robotic Handwriting and Drawing

Li, Boren 22 June 2012 (has links)
No description available.
606

Detecting Successful Throws

Almousa, Sami, Morad, Gorgis January 2023 (has links)
This project aims to create a robot system that can accurately figure out if the throws are successful. This can help make various industrial tasks more efficient. The system uses implemented methods to process data from fisheye camera data and depth sensor data, to check the quality of the throws. The main goal is to find out if the thrown object reaches its target or not, with more advanced tasks including predicting its path when frames are lost or not tracked properly.To put the system together the Robot Operating System (ROS) was used for handling data and processing, as well as different tools and techniques, like bag files and OpenCV. A variety of methods and algorithms were used to apply background subtraction, clustering, curve fitting, marking objects and drawing the path they take in the air. The depth sensor data processing is included to make up for the limitations of 2D camera data, providing more accurate and reliable tracking of thrown objects.
607

50-Year Catalogs of Uranus Trajectory Options with a New Python-Based Rapid Design Tool

Alec J Mudek (13129083) 22 July 2022 (has links)
<p>Ballistic and chemical trajectory options to Uranus are investigated for launch dates spanning 50 years. Trajectory solutions are found using STOUR, a patched conic propagator with an analytical ephemeris model. STOUR is heritage software developed by JPL and Purdue, written in FORTRAN. A total of 89 distinct gravity-assist paths to Uranus are considered, most of which will allow for a deep space maneuver (DSM) at some point along the path. For each launch year, the most desirable trajectory is identified and cataloged based on time of flight (up to 15 years), total $\Delta$V cost (DSM and capture maneuver), arrival $V_\infty$, and delivered payload. The Falcon Heavy (Recoverable), Vulcan VC6, Falcon Heavy (Expendable) and SLS Block 1B are considered to provide a range of low- to high-performance launch vehicle capabilities. A rough approximation of Starship's performance capabilities is also computed and applied to select years of launch dates. A flagship mission that delivers both a probe and an orbiter at Uranus is considered, which is approximated as a trajectory capable of delivering 2000 kg. Jupiter is unavailable as a gravity-assist body until the end of the 2020s but alternative gravity-assist paths exist, providing feasible trajectories even in years when Jupiter is not available. A rare Saturn-Uranus alignment in the late 2020's is identified which provides some such trajectory opportunities. A probe-and-orbiter mission to Uranus is feasible for a Vulcan VC6 with approximately 13 year flight times and for a Recoverable Falcon Heavy with approximately 14.5 year flight times. An Expendable Falcon Heavy reduces the time of flight to around 12.5 years and opens up `0E0U' as a gravity-assist path, while the SLS Block 1B typically offers trajectories with 10 to 11 year flight times and opens up more direct `JU' and `U' solutions. With the SLS, flight times as low as 7.5 years are possible.</p> <p>  </p> <p>A new, rapid grid search tool called GREMLINS is also outlined. This new software is capable of solving the same problems as STOUR, but improves on it in three crucial ways: an improved user-experience, more maneuver capabilities, and a more easily maintained and modified code base. GREMLINS takes a different approach to the broad search problem, forgoing $C_3$ matching in favor of using maneuvers to patch together tables of pre-computed Lambert arcs. This approach allows for vectorized computations across data frames of Lambert solutions, which can be computed much more efficiently than the for-loop style approach of past tools. Through the use of SQL tables and a two-step trajectory solving approach, this tool is able to run very quickly while still being able to handle any amount of data required for a broad search. Every line of code in GREMLINS is written in Python in an effort to make it more approachable and easier to develop for a wide community of users, as GREMLINS will be the only only grid search tool available as free and open source software. Multiple example missions and trajectory searches are explored to verify the output from GREMLINS and to compare its performance against STOUR. Despite using a slower coding language, GREMLINS is capable of performing the same trajectory searches in approximately 1/5 the runtime of STOUR, a FORTRAN-coded tool, thanks to its vectorized computations.</p>
608

[pt] PAIS E FILHOS: TRAJETÓRIAS DE DESENVOLVIMENTO DE CRENÇAS E VALORES MATERIALISTAS / [en] PARENTS AND CHILDREN: DEVELOPMENTAL TRAJECTORIES OF MATERIALIST BELIEFS AND VALUES

ALEXANDRE RODRIGUES SENA 22 January 2020 (has links)
[pt] O objetivo desse estudo foi investigar a relação entre a percepção dos filhos acerca das crenças e valores materialistas dos pais com os próprios sistemas de crenças e valores em seu percurso de desenvolvimento. Participaram da pesquisa 892 jovens, moradores dos 27 estados brasileiros e com idades entre 18 e 25 anos. De acordo com a fundamentação teórica, os pais são os principais responsáveis pela transmissão de crenças e valores aos filhos. Esse processo é dinâmico, interacional e pode ser alterado de acordo com as ênfases socioculturais e históricas de cada geração. Os jovens de 18 a 25 anos pertencem à Geração Y e seus pais, às gerações Baby Boomers e X. O estudo mostrou que, apesar das inúmeras e intensas transformações entre essas gerações no Ocidente, os valores e crenças materialistas foram transmitidos pelos pais durante a trajetória de vida dos filhos. As crenças sobre status, lucro, riqueza e autoridade podem ser utilizadas para definir os valores materialistas. A pesquisa apresentou que, no percurso da parentalidade material, a punição e a rejeição durante a adolescência estão possivelmente associadas à aquisição de valores e crenças materialistas no futuro. O estudo também apontou que, a transmissão geracional de valores e crenças materialistas pode ressaltar os objetivos de vida extrínsecos durante a trajetória de desenvolvimento. Acredita-se que esse estudo tenha contribuído para a área da Psicologia da Saúde e do Desenvolvimento. / [en] The purpose of this study was to investigate the relationship between children s perceptions of their parents beliefs and material values with their own belief systems and values in their developmental path. Eight hundred and ninety two young people (892), residents of the 27 Brazilian states and between the ages of 18 and 25 participated in the study. According to the theoretical framework, parents are the main responsible for the transmission of beliefs and values to their children. This process is dynamic, interactive and can be altered according to the sociocultural and historical emphases of each generation. Young people between the ages of 18 and 25 belong to generation Y and their parents, to the generations Baby Boomers and X. The study showed that, parents transmitted materialistic values and beliefs during their children s life trajectory, despite the numerous and intense transformations between these generations that happened in the West. Beliefs about status, profit, wealth, and authority can be used to define the materialistic values. The research showed that, in the course of material parenting, punishment and rejection during adolescence are possibly associated with the acquisition of materialistic values and beliefs in the future. The study also pointed out that the generational transmission of values and materialistic beliefs highlights the extrinsic life goals during the development trajectory. It is deemed that this study has contributed to the area of Health and Developmental Psychology.
609

Aircraft Contrail Prediction for Commercial Flights / Förutsägning av flygplans kondensspår för kommersiella flygningar

Kundgol, Chirag January 2022 (has links)
The prediction of contrails have been studied since the 1930s primarily for militaryapplications. In present times, contrail avoidance strategies are gaining popularity insustainable aviation. In this project, the theory behind their formation, persistenceand the mitigation strategies are explored, studied and implemented.Several methods are evaluated in order to predict the critical temperature. Aircraftparameters are included in the prediction of contrails and implemented. This dynamicprogramming is contrasted against real case operational flight plans.The first implementation considers an operational flight plan for which contrails are pre-dicted along the trajectory. The second involves the prediction of contrails at the end ofthe vertical trajectory optimisation. The optimisation for contrail persistence avoidanceis also accomplished. Results show that contrail persistence can be avoided. / Förutsägelsen av kondensspår har studerats sedan 1930-talet, främst för militära tillämp-ningar. I nutid, strategier för undvikande av långvariga kondensspår ökar i popularitetinom hållbar flygning. I det här examensarbetet, utforskas och studeras teorin bakombildning, uthållighet och begränsningsstrategier för kondensspår för att sedan imple-menteras.Flera metoder evalueras för att förutsäga den kritiska temperaturen. Flygplansparame-trar är inkluderade och implementerade i förutsägelsen av kondesspår. Den dynamiskaprogrammeringen jämförs mot verkliga operativa färdplaner.Den första implementeringen avser en operativ färdplan för vilken kondensspår förut-spås längs banan. Den andra implementeringen involverar förutsägelse av kondensspåri slutet av den vertikala banoptimeringen. Optimeringen med avseende på långvarigakondensspår genomförs också. Resultaten visar att långvariga kondensspår kan und-vikas.
610

Development of a Trajectory Modeling Software for Spacecrafts in Earth Orbit as well as Interplanetary Transfers

Basyal, Ishan January 2013 (has links)
Trajectory modeling is one of the most important aspects of any mission design. The trajectory should be able to propagate the S/C to the final destination while optimizing the flight duration, the total change in velocity and also the total launch mass. The Spacecraft Trajectory Optimizer (STO) tool described in this report first solves the Gauss Lambert problem and generates initial departure and arrival conditions which can also be expressed as porkchop plots. These initial conditions are then used as input to optimize the flight steps which are based on a patched conic approximation with the elliptical transfer with respect to the Sun and the hyperbolic transfers at the departure and arrival planet's sphere of influence. The tool is completely based on MATLAB 2007 or later and uses ODE45 for trajectory propagation and FMINCON with Active-set algorithm for optimization. The results obtained in house were compared with four Mars Sample return orbits calculated at ESOC and there is a very good correlation between the required change in velocities and transfer duration for e.g. Orbit case: O22S, ESOC values: total Delta V = 3.946 - 4.119 [km/s], TOF = 329 - 342 [days] &amp; STO values: Delta V = 3:986 [km/s] &amp; TOF = 335 [days]. The in house data was also used as an input in the System Tool Kit (a professional trajectory calculation software) for modeling an interplanetary trajectory to Mars and the S/C arrived at Mars without any optimization. Therefore, even though the STO does not have all the capabilities of a professional software it can be used for preliminary mission analysis as it offers quite accurate results for interplanetary transfers. / <p>Validerat; 20131127 (global_studentproject_submitter)</p>

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