3,042 research outputs found
Toward automatic censorship detection in microblogs
Social media is an area where users often experience censorship through a
variety of means such as the restriction of search terms or active and
retroactive deletion of messages. In this paper we examine the feasibility of
automatically detecting censorship of microblogs. We use a network growing
model to simulate discussion over a microblog follow network and compare two
censorship strategies to simulate varying levels of message deletion. Using
topological features extracted from the resulting graphs, a classifier is
trained to detect whether or not a given communication graph has been censored.
The results show that censorship detection is feasible under empirically
measured levels of message deletion. The proposed framework can enable
automated censorship measurement and tracking, which, when combined with
aggregated citizen reports of censorship, can allow users to make informed
decisions about online communication habits.Comment: 13 pages. Updated with example cascades figure and typo fixes. To
appear at the International Workshop on Data Mining in Social Networks
(PAKDD-SocNet) 201
Hannibal Central School District and Hannibal Education Association
In the matter of the fact-finding between the Hannibal Central School District, employer, and the Hannibal Education Association, union. PERB case no. M2012-106. Before: Clifford B. Donn, fact finder
Hannibal Central School District and Hannibal Faculty Association
In the matter of the fact-finding between the Hannibal Central School District, employer, and the Hannibal Faculty Association, union. PERB case no. M2012-372. Before: Clifford B. Donn, fact finder
Spoken affect classification : algorithms and experimental implementation : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Computer Science at Massey University, Palmerston North, New Zealand
Machine-based emotional intelligence is a requirement for natural interaction between humans and computer interfaces and a basic level of accurate emotion perception is needed for computer systems to respond adequately to human emotion. Humans convey emotional information both intentionally and unintentionally via speech patterns. These vocal patterns are perceived and understood by listeners during conversation. This research aims to improve the automatic perception of vocal emotion in two ways. First, we compare two emotional speech data sources: natural, spontaneous emotional speech and acted or portrayed emotional speech. This comparison demonstrates the advantages and disadvantages of both acquisition methods and how these methods affect the end application of vocal emotion recognition. Second, we look at two classification methods which have gone unexplored in this field: stacked generalisation and unweighted vote. We show how these techniques can yield an improvement over traditional classification methods
Laboratory Research
To properly interpret the rapidly growing body of data from comet observations, many types of laboratory measurements are needed. These include: (1) molecular spectroscopy in the visible, ultraviolet, infrared and microwave region of the spectra; (2) laser fluorescent spectroscopy of photofragments; (3) laboratory cross-section or reaction rate measurements using flow tube techniques, fluorescent spectroscopy detection for neutrals and ion-molecule reaction techniques; (4) experiments to simulate solar-wind interactions with comets; (5) studies of the properties and behavior of ice mixtures; (6) experiments on the sublimation rate of ice, and the phase transition from amorphous to crystalline ice; (7) investigations of the irradiation of ice; and (8) the electron impact dissociation and excitation of molecules of cometary interest. A nearly completed experiment on the proton irradiation of ice is described
A Comparison of the Composition of New and Evolved Comets
The intensity ratio of the continuum to the molecular emissions was estimated in the spectra of eight-five comets. Four conclusions are drawn: (1) There is no readily apparent difference in continuum to emission intensity ratio between new and more evolved comets; (2) an intrinsic distribution of this characteristic does occur; (3) periodic comets with weak continua are derived from new comets with the same property; and (4) no weakening of the continuum in general occurs following perihelion passage. The infrared evidence for comet Encke suggests that the faintness of its continuum may be caused by a size distribution containing only particles larger than about 10 um
Grain formation in astronomical systems: A critical review of condensation processes
An analysis is presented of the assumption and the applicability of the three theoretical methods for calculating condensations in cosmic clouds where no pre-existing nuclei exist. The three procedures are: thermodynamic equilibrium calculations, nucleation theory, and a kinetic treatment which would take into account the characteristics of each individual collision. Thermodynamics provide detailed results on the composition temperature and composition of the condensate provided the system attains equilibrium. Because of the cosmic abundance mixture of elements, large supersaturations in some cases and low pressures, equilibrium is not expected in astronomical clouds. Nucleation theory, a combination of thermodynamics and kinetics, has the limitations of each scheme. Kinetics, not requiring equilibrium, avoids nearly all the thermodynamics difficulties but requires detailed knowledge of many reactions which thermodynamics avoids. It appears to be the only valid way to treat grain formation in space. A review of experimental studies is given
Comets, interstellar clouds and star clusters
The association of comets with star formation in clusters is elaborated. This hypothesis is also used to explain origin and evaluation of the Oort cloud, the composition of comets, and relationships between cometary and interstellar molecules
Einstein-de Sitter model re-examined for the newly discovered SNe Ia
Consistency of Einstein-de Sitter model with the recently observed SNe Ia by
the Hubble Space Telescope is examined. The model shows a reasonable fit to the
observation, if one takes into account the extinction of SNe light by the
intergalactic metallic dust ejected from the SNe explosions. Though the fit to
the new data is worsened considerably compared with the earlier data, it can
still be regarded acceptable. We should wait for more accurate observations at
higher redshifts (as expected from the coming space missions such as SNAP and
JWST) in order to rule out a model, which seems to explain all the other
existing observations well (some even better than the favoured CDM
model), is consistent with beautiful theoretical ideas like inflation and cold
dark matter, and is not as speculative as the models of dark energy.Comment: 14 pages including 2 figures, to appear in the Mon. Not. Roy. Astron.
So
Structure and origin of cometary nuclei
There is strong evidence that a comet nucleus consists of a single object whose basic structure is Whipple's icy conglomerate. A number of cometary phenomena indicate that the nucleus is a low density, fragile object with a large degree of radial uniformity in structure and composition. Details of the ice-dust pattern are more uncertain. A working model is proposed which is based on theories of accumulation of larger objects from grains. This nucleus is a distorted spherical aggregate of a hierarchy of ice-dust cometesimals. These cometesimals retain some separate identity which lead to comet fragmentation when larger components break off. The outer layers of new comets were modified by cosmic ray irradiation in the Oort Cloud. The evidence for meteorite-comet association is steill controversial. Current dynamical studies do not seem to require a cometary source of meteorites
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