3,040 research outputs found
Vocable Code
Vocable Code is both a work of âsoftware artâ (software as artwork, not software to make an artwork) and a âcodeworkâ (where the source code and critical writing operate together) produced to embody âqueer codeâ. Collective statements and voices complete the phrase âQueer isâŠâ and together make a computational and poetic composition for two screens: on one of these, texts and voices are repeated and disrupted by mathematical chaos, together exploring the performativity of code and language; on the other, is a mix of a computer programming syntax and human language. In this sense queer code can be understood as both an object and subject of study that intervenes in the worldâs âbecomingâ and how material bodies are produced via human and nonhuman practices. Through mixing the natural and computer language, this article presents a script in six parts from a performative lecture for two persons and a computer. The purpose is to exemplify the speech-like qualities of a computer program, and to explore the constant regeneration and re-running of code as a way to rethink computational logic from a posthuman position
Vocable Code (13082018): A lecture-performance in six parts
Vocable Code (13082018) is both a work of âsoftware artâ (software as artwork, not software to make an artwork) and a âcodeworkâ (where the source code and critical writing operate together) produced to embody âqueer codeâ, examining the notion of queerness in computer coding through the interplay of different human and nonhuman voices
The focal plane reception pattern calculation for a paraboloidal antenna with a nearby fence
A computer simulation program is described which is used to estimate the effects of a proximate diffraction fence on the performance of paraboloid antennas. The computer program is written in FORTRAN. The physical problem, mathematical formulation and coordinate references are described. The main control structure of the program and the function of the individual subroutines are discussed. The Job Control Language set-up and program instruction are provided in the user's instruction to help users execute the present program. A sample problem with an appropriate output listing is made available as an illustration of the usage of the program
Solar Flare Intermittency and the Earth's Temperature Anomalies
We argue that earth's short-term temperature anomalies and the solar flare
intermittency are linked. The analysis is based upon the study of the scaling
of both the spreading and the entropy of the diffusion generated by the
fluctuations of the temperature time series. The joint use of these two methods
evidences the presence of a L\'{e}vy component in the temporal persistence of
the temperature data sets that corresponds to the one that would be induced by
the solar flare intermittency. The mean monthly temperature datasets cover the
period from 1856 to 2002.Comment: 4 pages, 5 figure
Magnetic cycles at different ages of stars
We study the different patterns of interannual magnetic variability in stars
on or near the lower main sequence, approximately solar-type (G-K dwarf) stars
in time series of 36 years from the Mount Wilson Observatory Ca\,{\sc ii}\,H\&K
survey. Our main aim is to search for correlations between cycles, activity
measures and ages. Time-frequency analysis has been used to discern and reveal
patterns and morphology of stellar activity cycles, including multiple and
changing cycles, in the datasets. Both the results from short-term Fourier
transform and its refinement using the Choi-Williams distribution, with better
frequency resolution, are presented in this study. Rotational periods of the
stars were derived using multi-frequency Fourier analysis.From the studied 29
stars we found at least one activity cycle on 28 of them. Twelve stars, with
longer rotational periods ( days) have simple, smooth cycles, and
the rest of the stars, with on-average much faster rotation (
days) show complex and sometimes vigorously changing, multiple cycles. The
cycles are longer and quite uniform in the first group ( years),
while are generally shorter and with greater variety in the second one
(). There is a clear age division between stars with smooth and
complex cycles that follows the known separation between the older and younger
stars at around 2 to 3~Gyr of age.Comment: Accepted to Astronomy and Astrophysic
Climate hypersensitivity to solar forcing?
International audienceWe compare the equilibrium climate responses of a quasi-dynamical energy balance model to radiative forcing by equivalent changes in CO2, solar total irradiance (Stot) and solar UV (SUV). The response is largest in the SUV case, in which the imposed UV radiative forcing is preferentially absorbed in the layer above 250 mb, in contrast to the weak response from global-columnar radiative loading by increases in CO2 or Stot. The hypersensitive response of the climate system to solar UV forcing is caused by strongly coupled feedback involving vertical static stability, tropical thick cirrus ice clouds and stratospheric ozone. This mechanism offers a plausible explanation of the apparent hypersensitivity of climate to solar forcing, as suggested by analyses of recent climatic records. The model hypersensitivity strongly depends on climate parameters, especially cloud radiative properties, but is effective for arguably realistic values of these parameters. The proposed solar forcing mechanism should be further confirmed using other models (e.g., general circulation models) that may better capture radiative and dynamical couplings of the troposphere and stratosphere
Propellant-Free Control of Tethered Formation Flight, Part 1: Linear Control and Experimentation
We introduce a decentralized attitude control strategy that can dramatically reduce the usage of propellant, by
taking full advantage of the physical coupling of the tether. Motivated by a controllability analysis, indicating that both array resizing and spin-up are fully controllable by the reaction wheels and the tether motor, we report the first propellant-free underactuated control results for tethered formation flying spacecraft. This paper also describes the hardware development and experimental validation of the proposed method using the Synchronized Position Hold, Engage, and Reorient Experimental Satellites test bed. In particular, a new relative sensing mechanism that uses sixderee-of-freedom force-torque sensors and rate gyroscopes is introduced and validated in the closed-loop control experiments
Managing the cardiovascular complications of chronic kidney disease
Patients with chronic kidney disease have risk factors for cardiovascular disease which are additional to those found in the general population. Many patients will die of cardiovascular disease before they require dialysis for their kidney disease. While lifestyle modification is essential, it is important to manage the patient's anaemia, dyslipidaemia and hypertension. Managing heart failure can be difficult because of the need to adjust the patient's fluid balance according to renal and cardiac function. If the progression of chronic kidney disease can be slowed, cardiac risk may be reduced. (author abstract
Design, Implementation and Operation of a Sparse Aperture Imaging Satellite Testbed
In order to better understand the technological difficulties involved in designing and building a sparse aperture array, the challenge of building a white light Golay-3 telescope was undertaken. The MIT Adaptive Reconnaissance Golay-3 Optical Satellite (ARGOS) project exploits wide-angle Fizeau interferometer technology with an emphasis on modularity in the optics and spacecraft subsystems. Unique design procedures encompassing the nature of coherent wavefront sensing, control and combining as well as various system engineering aspects to achieve cost effectiveness, are developed. To demonstrate a complete spacecraft in a 1-g environment, the ARGOS system is mounted on a frictionless air-bearing, and has the ability to track fast orbiting satellites like the ISS or the planets. Wavefront sensing techniques are explored to mitigate initial misalignment and to feed back real-time aberrations into the optical control loop. This paper presents the results and the lessons learned from the conceive, design, implement and operate phases of ARGOS. A preliminary assessment shows that the beam combining problem is the most challenging aspect of sparse optical arrays. The need for optical control is paramount due to tight beam combining tolerances. The wavefront sensing/control requirements appear to be a major technology and cost driver
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