14,649 research outputs found
A Commander’s Power, A Civilian’s Reason: Justice Jackson’s Korematsu Dissent
Barrett examines the dissent opinion of Supreme Court Justice Robert Houghwout Jackson in Korematsu v. United States, which centered on the internment of Japanese Americans during WWII. Although the dissent has been criticized as incoherent, it contains strong legal implications within its complexity
The Independent Counsel Investigation, the Impeachment Proceedings, and President Clinton\u27s Defense: Inquiries into the Role and Responsibilities of Lawyers, Symposium, The Leak and the Craft: A Hard Line Proposal To Stop Unaccountable Disclosures of Law Enforcement Information
Anomalous pattern based clustering of mental tasks with subject independent learning – some preliminary results
In this paper we describe a new method for EEG signal classification in which the classification of one subject’s EEG signals is based on features learnt from another subject. This method applies to the power spectrum density data and assigns class-dependent information weights to individual features. The informative features appear to be rather similar among different subjects, thus supporting the view that there are subject independent general brain patterns for the same mental task. Classification is done via clustering using the intelligent k-means algorithm with the most informative features from a different subject. We experimentally compare our method with others.</jats:p
Keeping New Teachers: A First Look at the Influences of Induction in the Chicago Public Schools
Examines whether participation in a formal induction program can improve teachers' experiences and job satisfaction, and demonstrates that strong levels of mentoring and support for new teachers greatly improve their desire to continue teaching
Non-Equilibrium Ionization Model for Stellar Cluster Winds and its Application
We have developed a self-consistent physical model for super stellar cluster
winds based on combining a 1-D steady-state adiabatic wind solution and a
non-equilibrium ionization calculation. Comparing with the case of collisional
ionization equilibrium, we find that the non-equilibrium ionization effect is
significant in the regime of a high ratio of energy to mass input rate and
manifests in a stronger soft X-ray flux in the inner region of the star
cluster. Implementing the model in X-ray data analysis softwares (e.g., XSPEC)
directly facilitates comparisons with X-ray observations. Physical quantities
such as the mass and energy input rates of stellar winds can be estimated by
fitting observed X-ray spectra. The fitted parameters may then be compared with
independent measurements from other wavelengths. Applying our model to the star
cluster NGC 3603, we find that the wind accounts for no more than 50% of the
total "diffuse" emission, and the derived mass input rate and terminal velocity
are comparable to other empirical estimates. The remaining emission most likely
originate from numerous low-mass pre-main-sequence stellar objects.Comment: 29 pages, 17 figures. accepted by MNRA
Wavelet Lifting over Information-Based EEG Graphs for Motor Imagery Data Classification
The imagination of limb movements offers an intuitive paradigm for the control of electronic devices via brain computer interfacing (BCI). The analysis of electroencephalographic (EEG) data related to motor imagery potentials has proved to be a difficult task. EEG readings are noisy, and the elicited patterns occur in different parts of the scalp, at different instants and at different frequencies. Wavelet transform has been widely used in the BCI field as it offers temporal and spectral capabilities, although it lacks spatial information. In this study we propose a tailored second generation wavelet to extract features from these three domains. This transform is applied over a graph representation of motor imaginary trials, which encodes temporal and spatial information. This graph is enhanced using per-subject knowledge in order to optimise the spatial relationships among the electrodes, and to improve the filter design. This method improves the performance of classifying different imaginary limb movements maintaining the low computational resources required by the lifting transform over graphs. By using an online dataset we were able to positively assess the feasibility of using the novel method in an online BCI context
The correlation space of Gaussian latent tree models and model selection without fitting
We provide a complete description of possible covariance matrices consistent
with a Gaussian latent tree model for any tree. We then present techniques for
utilising these constraints to assess whether observed data is compatible with
that Gaussian latent tree model. Our method does not require us first to fit
such a tree. We demonstrate the usefulness of the inverse-Wishart distribution
for performing preliminary assessments of tree-compatibility using
semialgebraic constraints. Using results from Drton et al. (2008) we then
provide the appropriate moments required for test statistics for assessing
adherence to these equality constraints. These are shown to be effective even
for small sample sizes and can be easily adjusted to test either the entire
model or only certain macrostructures hypothesized within the tree. We
illustrate our exploratory tetrad analysis using a linguistic application and
our confirmatory tetrad analysis using a biological application.Comment: 15 page
Abell 2111: An Optical and Radio Study of the Richest Butcher-Oemler Cluster
We present an in-depth analysis of the Butcher-Oemler cluster A2111,
including new optical spectroscopy plus a deep Very Large Array (VLA) radio
continuum observation. These are combined with optical imaging from the Sloan
Digital Sky Survey (SDSS) to assess the activity and properties of member
galaxies. Prior X-ray studies have suggested A2111 is a head-on cluster merger,
a dynamical state which might be connected to the high level of activity
inferred from its blue fraction. We are able to directly assess this claim,
using our spectroscopic data to identify 95 cluster members among 196 total
galaxy spectra. These galaxy velocities do not themselves provide significant
evidence for the merger interpretation, however they are consistent with it
provided the system is viewed near the time of core passage and at a viewing
angle >~30 degrees different from the merger axis. The SDSS data allow us to
confirm the high blue fraction for A2111, f_b = 0.15 +/- 0.03 based on
photometry alone and f_b = 0.23 +/- 0.03 using spectroscopic data to remove
background galaxies. We are able to detect 175 optical sources from the SDSS in
our VLA radio data, of which 35 have redshift information. We use the SDSS
photometry to determine photometric redshifts for the remaining 140
radio-optical sources. In total we identify up to 26 cluster radio galaxies, 14
of which have spectroscopic redshifts. The optical spectroscopy and radio data
reveal a substantial population of dusty starbursts within the cluster. The
high blue fraction and prevalence of star formation is consistent with the
hypothesis that dynamically-active clusters are associated with more active
member galaxies than relaxed clusters.Comment: To appear in AJ; 53 pages including 10 figures and several long
table
Censoring, Factorizations, and Spectral Analysis for Transition Matrices with Block-Repeating Entries
In this paper, we use the Markov chain censoring technique to study infinite state Markov chains whose transition matrices possess block-repeating entries. We demonstrate that a number of important probabilistic measures are invariant under censoring. Informally speaking, these measures involve first passage times or expected numbers of visits to certain levels where other levels are taboo;they are closely related to the so-called fundamental matrix of the Markov chain which is also studied here. Factorization theorems for the characteristic equation of the blocks of the transition matrix are obtained. Necessary and sufficient conditions are derived for such a Markov chain to be positive recurrent, null recurrent, or transient based either on spectral analysis, or on a property of the fundamental matrix. Explicit expressions are obtained for key probabilistic measures, including the stationary probability vector and the fundamental matrix, which could be potentially used to develop various recursivealgorithms for computing these measures.block-Toeplitz transition matrices, factorization of characteristic functions, spectral analysis, fundamental matrix, conditions of recurrence and transience.
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