1,721,042 research outputs found
PHOnA: A Public Dataset of Measured Headphone Transfer Functions
No full textA dataset of measured headphone transfer functions (HpTFs), the Princeton Headphone Open Archive (PHOnA), is presented. Extensive studies of HpTFs have been conducted for the past twenty years, each requiring a separate set of measurements, but this data has not yet been publicly shared. PHOnA aggregates HpTFs from different laboratories, including measurements for multiple different headphones, subjects, and repositionings of headphones for each subject. The dataset uses the spatially..
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Development of A Megawatt Class alpha^2+ Magnetoplasmadynamic Thruster and beginning steps for accompanying control system for autonomous monitoring of operational envelope
No full textWith the rising demand for deep space missions meant to either explore or collect data, it becomes increasingly necessary that newer systems and mechanisms are developed to support this growing need. In the context of long term missions, this implies the need for more powerful electric propulsion systems as they are most often relied upon for missions of this kind. Previous work on electric propulsion methods has focused on better characterizing and improving operation of already existing magnetoplasmadynamic thrusters. This is done in order to improve these thrusters as they are among the best options for long term space travel under past limitations. This thesis will do the following: 1) show how new considerations of nuclear power will allow for designing a feasible and more desirable thruster capable of utilizing large power sources for long term missions, 2) outline the process to implement a control system to allow for autonomous monitoring and correction of the designed thruster. This thesis will first motivate the work done as well as outline the underlying science driving this research after briefly explaining the necessity of electric propulsion for deep space missions. It will also address the change in topic scope as a result of limitations imposed by COVID-19. This thesis will then begin the process to developing this megawatt class thruster by first demonstrating an understanding of key Tikhonov relations. Afterwards, the Tikhonnv relations will be used to develop both operational parameters and dimensions for the megawatt class thruster. Finally, these Tikhonov relations will then be used to identify key parameters to be monitored for control system applications
Prediction of a Decompression Induced Mist Stand Off Distance For a Natural Convection System and the Design of a Novel Hygrometer
No full textControl and Analysis of a JxB Pump Propellant Feed System for the Lithium Lorentz Force Accelerator
No full textThe Lithium Lorentz Force Accelerator (LiLFA) is an applied-field magnetoplasma-dynamic thruster (AF-MPDT) within Princeton University’s Electric Propulsion and Plasma Dynamics Laboratory. Lithium propellant is fed to the thruster via an electromagnetic pump system. Tests of the pump using gallium were completed in order to measure possible mass flow rates and to determine whether or not desired precision could be achieved. In order to measure these flow rates, an induction probe measurement technique was employed in order to record the depletion of propellant in the feed system reservoir. Upon verification of successful pump operation and flow rate measurement, a new vacuum-sealed feed system was fabricated in order to accommodate lithium’s corrosive and reactive properties. Current testing of the lithium setup is proving faulty. Further experimentation will be required in order to ensure robustness of the feed system and to determine whether or not success with lithium propellant is possible with the current setup
Analysis of Space Debris Deorbit through Applied Impulse from a Satellite-Borne Short Pulse Laser
No full text
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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