1,921 research outputs found
Turtle Beach
This paper thoroughly examines the production of the thesis film, Turtle Beach. Each area of the film’s production is carefully dissected, including the writing, production design, cinematography, directing, editing, sound, technology, workflow and visual effect. Specific attention has been paid to writing and cinematography, and how they affect editing
An Improved Sideband Current Harmonic Model of Interior PMSM Drive by Considering Magnetic Saturation and Cross-Coupling Effects
The sideband current harmonics, as parasitic characteristics in permanent-magnet synchronous machine (PMSM) drives with space vector pulsewidth modulation technique, will increase the corresponding electromagnetic loss, torque ripple, vibration, and acoustic noises. Therefore, fast yet accurate evaluation of the resultant sideband current harmonic components is of particular importance during the design stage of the drive system. However, the inevitable magnetic saturation and cross-coupling effects in interior PMSM drives would have a significant impact on the current components, while the existing analytical sideband current harmonic model neglects those effects. This paper introduces a significant improvement on the analytical model by taking into account these effects with corresponding nonlinear factors. Experimental results are carried out to underpin the accuracy improvements of the predictions from the proposed model over the existing analytical one. The proposed model can offer a very detailed and insightful revelation of impacts of the magnetic saturation and cross-coupling effects on the corresponding sideband current harmonics
Optimal trajectory generation with DMOC versus NTG : application to an underwater glider and a JPL aerobot.
Optimal trajectory generation is an essential part for robotic explorers to execute the total exploration of deep oceans or outer space planets while curiosity of human and technology advancements of society both require robots to search for unknown territories efficiently and safely. As one of state-of-the-art optimal trajectory generation methodologies, Nonlinear Trajectory Generation (NTG) combines with B-spline, nonlinear programming, differential flatness technique to generate optimal trajectories for modelled mechanical systems. While Discrete Mechanics and Optimal Control (DMOC) is a newly proposed optimal control method for mechanical systems, it is based on direct discretization of Lagrange-d\u27Alembert principle. In this dissertation, NTG is utilized to generate trajectories for an underwater glider with a 3D B-spline ocean current model. The optimal trajectories are corresponding well with the Lagrangian Coherent Structures (LCS). Then NTG is utilized to generate 3D opportunistic trajectories for a JPL (Jet Propulsion Laboratory) Aerobot by taking advantage of wind velocity. Since both DMOC and NTG are methods which can generate optimal trajectories for mechanical systems, their differences in theory and application are investigated. In a simple ocean current example and a more complex ocean current model, DMOC with discrete Euler-Lagrange constraints generates local optimal solutions with different initial guesses while NTG is also generating similar solutions with more computation time and comparable energy consumption. DMOC is much easier to implement than NTG because in order to generate good solutions in NTG, its variables need to be correctly defined as B-spline variables with rightly-chosen orders. Finally, the MARIT (Multiple Air Robotics Indoor Testbed) is established with a Vicon 8i motion capture system. Six Mcam 2 cameras connected with a datastation are able to track real-time coordinates of a draganflyer helicopter. This motion capture system establishes a good foundation for future NTG and DMOC algorithms verifications
PSYCHOLOGICAL OBSTACLES AND COUNTERMEASURES OF COLLEGE STUDENTS\u27 ENGLISH LEARNING BASED ON PSYCHOLINGUISTICS
PSYCHOLOGICAL OBSTACLES AND COUNTERMEASURES OF COLLEGE STUDENTS\u27 ENGLISH LEARNING BASED ON PSYCHOLINGUISTICS
Synthesis and characterization of plasma enhanced chemically vapor deposited tantalum films
A low temperature inorganic plasma-enhanced chemical vapor deposition (PECVD) process has been developed for the growth of Ta using tantalum pentachloride (TaC15) as the preferred precursor and hydrogen as the reactant gas. Ta coatings were deposited at substrate temperature of 370-400 °C, reactor working pressures of 0.7-2 Ton, hydrogen carrier flow rate of 10-20 sccm, hydrogen reactant flow rates of 500 sccm, and plasma power ranging from 60 to 100W. Ta coatings were characterized with respect to their chemical, structural, and morphological properties by Auger electron spectroscopy (AES), x-ray diffraction (XRD), atomic force microscopy (AFM), x-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and x-ray reflectivity (XRR). The hydrogen concentration was detected by NRA. These studies indicated that a phase predominant Ta coatings with traces of oxygen, carbon, chlorine, and hydrogen were deposited by PECVD method.
The coatings properties had been investigated in relation to deposition temperature, precursor temperature, RF input power, plasma working distance and reactant concentration. The growth rate was significantly enhanced by decreasing the plasma working distance between the plasma shower head and substrate. The growth rate increased with increasing in the precursor temperatures and deposition temperatures. The plasma working distance was also discussed as the main experimental parameter to cause a-phase formation in PECVD Ta deposition. The in-situ annealing process was produced to evaluate effects of thermal treatment of Ta phase formation. XRR measurements showed that the density of the CVD Ta coatings is closed to that of bulk Ta.
The various seed layers were used to try to promote the a-phase formation, such as Cr, Au, Nb, Pt, Ti, and TaNx. Tantalum coatings had successfully been deposited on all different seed layers. The SEM results exhibited dense Ta coatings with perfectly conformal coverage. The typical topography of CVD Ta coatings were indicated by AFM analysis. The a-phase promoting effect of those seed layers was indicated by XRD analysis. XRD analysis indicates that mixture a and 13 phase were deposited on the Cr seed layers, but Cr seed layers do not promote a phase formation. However, sputtered Cr gave more crystalline R phase formation. CVD Ta coatings deposited on Nb and Au seed layers no longer exhibited evidence of 13 phase. XRD results of CVD Ta coatings deposited on TaNx seed layers showed predominant presence of a phase formation
Multidimensionality of Power Use in Organizations and its Correlates
The present study was conducted to examine power use patterns and general power use strategies in organizations multidimensionally (i.e., downward, upward, and lateral directions of power use), to extend and explain previous findings by Kipnis et al. (1980), with reference to situational effects on multidimensional power use. The samples in this study consist of 230 full-time managers who were from eight local businesses, and a second sample of 140 college students who worked over 15 hours a week at the time of the study. Two exploratory factor analyses resulted in five commonly used power patterns and two general power use strategies based on the eight factors found from Kipnis et al. (1980) factor analysis. Significant differences between the manager\u27s level and manager\u27s power tactics use were not found in downward, upward, or lateral power tactics use when three corresponding MANOVA analyses were conducted. Two different measures of work unit size were used, and the relationship between the work unit size and manager\u27s power tactics use was significant when tested by a stepwise multiple regression analysis. A final multivariate analysis with repeated measures found no significant difference between the two response formats used on the questionnaires given to the college student sample. The important implications and contributions of the present study are discussed as well as future research directions
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An on-line library of design patterns
This project is to develop an on-line library to help software engineers who utilize design patterns for developing e-commerce applications it translates generic design patterns to concrete design patterns. The graphical user interface was developed to allow the user to develop their own design patterns by modifying or changing stored design patterns
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