6,832 research outputs found
Particle impact location detector
Detector includes delay lines connected to each detector surface strip. When several particles strike different strips simultaneously, pulses generated by each strip are time delayed by certain intervals. Delay time for each strip is known. By observing time delay in pulse, it is possible to locate strip that is struck by particle
A cosmic dust composition analyzed with a spark ion source
Simulated iron micrometeoroids were fired unto a capacitor-type micrometeoroid detector which responded to an impact with a spark. Large ion currents were extracted from the spark and analyzed in a crude ion time-of-flight mass spectrometer. The mass spectra show the elements of both detector and particle materials
Micrometeoroid velocity-and-trajectory analyzer
By adding potential energy of charged capacitor to kinetic energy of impacting particle, new technique causes major fraction of atoms in microscopic particle impacting on particle-receiving surface to be ionized. Chemical constituents of impacting particle are represented by generated ion mass spectrum in approximately correct proportions
Revisiting Visual Question Answering Baselines
Visual question answering (VQA) is an interesting learning setting for
evaluating the abilities and shortcomings of current systems for image
understanding. Many of the recently proposed VQA systems include attention or
memory mechanisms designed to support "reasoning". For multiple-choice VQA,
nearly all of these systems train a multi-class classifier on image and
question features to predict an answer. This paper questions the value of these
common practices and develops a simple alternative model based on binary
classification. Instead of treating answers as competing choices, our model
receives the answer as input and predicts whether or not an
image-question-answer triplet is correct. We evaluate our model on the Visual7W
Telling and the VQA Real Multiple Choice tasks, and find that even simple
versions of our model perform competitively. Our best model achieves
state-of-the-art performance on the Visual7W Telling task and compares
surprisingly well with the most complex systems proposed for the VQA Real
Multiple Choice task. We explore variants of the model and study its
transferability between both datasets. We also present an error analysis of our
model that suggests a key problem of current VQA systems lies in the lack of
visual grounding of concepts that occur in the questions and answers. Overall,
our results suggest that the performance of current VQA systems is not
significantly better than that of systems designed to exploit dataset biases.Comment: European Conference on Computer Visio
The paradoxes of the revolutions of 1989 in central Europe
The self-limiting revolutions of 1989 in Central Europe offer an alternative paradigm of revolutionary change that is reminiscent more of the American struggle for independence in 1776 than the Jacobin tendencies that grew out of the French Revolution of 1789. In order to understand the contradictory impulses of the revolutions of 1989 - the desire for a radical renewal and the concern for preservation - this article takes as its point of departure the political thought of Hannah Arendt and Edmund Burke.published_or_final_versio
A composition analyzer for microparticles using a spark ion source
Iron microparticles were fired onto a capacitor-type microparticle detector which responded to an impact with a spark discharge. Ion currents were extracted from the spark and analyzed in a time-of-flight mass spectrometer. The mass spectra showed the element of both detector and particle materials. The total extracted ion currents was typically 10A within a period of 100ns, indicating very efficient vaporization of the particle and ionization of the vapor. Potential applications include research on cosmic dust, atmospheric aerosols and cloud droplets, particles ejected by rocket or jet engines, by machining processes, or by nuclear bomb explosions
Europe between reckless optimism and reckless despair
The article offers thoughts on the status of politics in Europe. According to the author, the call of the European Union's (EU) elite on the creation of 'more Europe' destroys the societies more politically. Revolutions that influence the future of Europe are being discussed. Additionally, the author argues that the protracted crisis of European integration has caused the deteriorating economic and political condition to European nations.published_or_final_versio
Colloidal crystal growth at externally imposed nucleation clusters
We study the conditions under which and how an imposed cluster of fixed
colloidal particles at prescribed positions triggers crystal nucleation from a
metastable colloidal fluid. Dynamical density functional theory of freezing and
Brownian dynamics simulations are applied to a two-dimensional colloidal system
with dipolar interactions. The externally imposed nucleation clusters involve
colloidal particles either on a rhombic lattice or along two linear arrays
separated by a gap. Crystal growth occurs after the peaks of the nucleation
cluster have first relaxed to a cutout of the stable bulk crystal.Comment: 4 pages, accepted for publication in Phys. Rev. Let
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