4,266 research outputs found
Recruitment Market Trend Analysis with Sequential Latent Variable Models
Recruitment market analysis provides valuable understanding of
industry-specific economic growth and plays an important role for both
employers and job seekers. With the rapid development of online recruitment
services, massive recruitment data have been accumulated and enable a new
paradigm for recruitment market analysis. However, traditional methods for
recruitment market analysis largely rely on the knowledge of domain experts and
classic statistical models, which are usually too general to model large-scale
dynamic recruitment data, and have difficulties to capture the fine-grained
market trends. To this end, in this paper, we propose a new research paradigm
for recruitment market analysis by leveraging unsupervised learning techniques
for automatically discovering recruitment market trends based on large-scale
recruitment data. Specifically, we develop a novel sequential latent variable
model, named MTLVM, which is designed for capturing the sequential dependencies
of corporate recruitment states and is able to automatically learn the latent
recruitment topics within a Bayesian generative framework. In particular, to
capture the variability of recruitment topics over time, we design hierarchical
dirichlet processes for MTLVM. These processes allow to dynamically generate
the evolving recruitment topics. Finally, we implement a prototype system to
empirically evaluate our approach based on real-world recruitment data in
China. Indeed, by visualizing the results from MTLVM, we can successfully
reveal many interesting findings, such as the popularity of LBS related jobs
reached the peak in the 2nd half of 2014, and decreased in 2015.Comment: 11 pages, 30 figure, SIGKDD 201
Superclustering at Redshift Z=0.54
We present strong evidence for the existence of a supercluster at a redshift
of z=0.54 in the direction of Selected Area 68. From the distribution of
galaxies with spectroscopic redshifts we find that there is a large
over-density of galaxies (a factor of four over the number expected in an
unclustered universe) within the redshift range 0.530 < z < 0.555. By
considering the spatial distribution of galaxies within this redshift range
(using spectroscopic and photometric redshifts) we show that the galaxies in
SA68 form a linear structure passing from the South-West of the survey field
through to the North-East (with a position angle of approximately 35 deg East
of North). This position angle is coincident with the positions of the X-ray
clusters CL0016+16, RX J0018.3+1618 and a new X-ray cluster, RX J0018.8+1602,
centered near the radio source 54W084. All three of these sources are at a
redshift of approximately z=0.54 and have position angles, derived from their
X-ray photon distributions, consistent with that measured for the supercluster.
Assuming a redshift of 0.54 for the distribution of galaxies and a FWHM
dispersion in redshift of 0.020 this represents a coherent structure with a
radial extent of 31 Mpc, transverse dimension of 12 Mpc, and a thickness of
approximately 4 Mpc. The detection of this possible supercluster demonstrates
the power of using X-ray observations, combined with multicolor observations,
to map the large scale distribution of galaxies at intermediate redshifts.Comment: 12 pages, 3 figures, Latex, aaspp4.sty, accepted for publication in
Ap J Letters. Figure 3 and followup observations can be found at
http://tarkus.pha.jhu.edu/~ajc/papers/supercluster
The XMM-Newton Project
The abundance of high-redshift galaxy clusters depends sensitively on the
matter density \OmM and, to a lesser extent, on the cosmological constant
. Measurements of this abundance therefore constrain these fundamental
cosmological parameters, and in a manner independent and complementary to other
methods, such as observations of the cosmic microwave background and distance
measurements. Cluster abundance is best measured by the X-ray temperature
function, as opposed to luminosity, because temperature and mass are tightly
correlated, as demonstrated by numerical simulations. Taking advantage of the
sensitivity of XMM-Newton, our Guaranteed Time program aims at measuring the
temperature of the highest redshift (z>0.4) SHARC clusters, with the ultimate
goal of constraining both \OmM and .Comment: To appear in the Proceedings of the XXI Moriond Conference: Galaxy
Clusters and the High Redshift Universe Observed in X-rays, edited by D.
Neumann, F. Durret, & J. Tran Thanh Va
Sex differences in exercise-induced diaphragmatic fatigue in endurance-trained athletes
There is evidence that female athletes may be more susceptible to exercise-induced arterial hypoxemia and expiratory flow limitation and have greater increases in operational lung volumes during exercise relative to men. These pulmonary limitations may ultimately lead to greater levels of diaphragmatic fatigue in women. Accordingly, the purpose of this study was to determine whether there are sex differences in the prevalence and severity of exercise-induced diaphragmatic fatigue in 38 healthy endurance-trained men (n = 19; maximal aerobic capacity = 64.0 ± 1.9 ml·kg–1·min–1) and women (n = 19; maximal aerobic capacity = 57.1 ± 1.5 ml·kg–1·min–1). Transdiaphragmatic pressure (Pdi) was calculated as the difference between gastric and esophageal pressures. Inspiratory pressure-time products of the diaphragm and esophagus were calculated as the product of breathing frequency and the Pdi and esophageal pressure time integrals, respectively. Cervical magnetic stimulation was used to measure potentiated Pdi twitches (Pdi,tw) before and 10, 30, and 60 min after a constant-load cycling test performed at 90% of peak work rate until exhaustion. Diaphragm fatigue was considered present if there was a 15% reduction in Pdi,tw after exercise. Diaphragm fatigue occurred in 11 of 19 men (58%) and 8 of 19 women (42%). The percent drop in Pdi,tw at 10, 30, and 60 min after exercise in men (n = 11) was 30.6 ± 2.3, 20.7 ± 3.2, and 13.3 ± 4.5%, respectively, whereas results in women (n = 8) were 21.0 ± 2.1, 11.6 ± 2.9, and 9.7 ± 4.2%, respectively, with sex differences occurring at 10 and 30 min (P < 0.05). Men continued to have a reduced contribution of the diaphragm to total inspiratory force output (pressure-time product of the diaphragm/pressure-time product of the esophagus) during exercise, whereas diaphragmatic contribution in women changed very little over time. The findings from this study point to a female diaphragm that is more resistant to fatigue relative to their male counterparts
Assessment of Connections Between Knowledge- Based Economy Characteristics and Selected Macroeconomic Categories in the European Union's Countries by Means of Panel Models
The aim of the article is to analyze the impact of knowledge-based economy variables on the selected macroeconomic categories - the share of total investments in GDP and the employment rate- in European Union's countries in the years 2000-2007, conducted with application of panel models.Celem artykułu jest analiza wpływu zmiennych opisujących gospodarkę opartą na wiedzy na podstawowe kategorie makroekonomiczne - udział całkowitych inwestycji w PKB i stopę zatrudnienia - w krajach Unii Europejskiej (z podziałem na kraje UE-15 i nowe kraje członkowskie UE) w latach 2000-2007, przeprowadzona w oparciu o modele panelowe
An extension of the SHARC survey
We report on our search for distant clusters of galaxies based on optical and
X-ray follow up observations of X-ray candidates from the SHARC survey. Based
on the assumption that the absence of bright optical or radio counterparts to
possibly extended X-ray sources could be distant clusters. We have obtained
deep optical images and redshifts for several of these objects and analyzed
archive XMM-Newton or Chandra data where applicable. In our list of candidate
clusters, two are probably galaxy structures at redshifts of z0.51 and
0.28. Seven other structures are possibly galaxy clusters between z0.3
and 1. Three sources are identified with QSOs and are thus likely to be X-ray
point sources, and six more also probably fall in this category. One X-ray
source is spurious or variable. For 17 other sources, the data are too sparse
at this time to put forward any hypothesis on their nature. We also
serendipitously detected a cluster at z=0.53 and another galaxy concentration
which is probably a structure with a redshift in the [0.15-0.6] range. We
discuss these results within the context of future space missions to
demonstrate the necessity of a wide field of view telescope optimized for the
0.5-2 keV range.Comment: Accepted in A&
Response Functions to Critical Shocks in Social Sciences: An Empirical and Numerical Study
We show that, provided one focuses on properly selected episodes, one can
apply to the social sciences the same observational strategy that has proved
successful in natural sciences such as astrophysics or geodynamics. For
instance, in order to probe the cohesion of a policy, one can, in different
countries, study the reactions to some huge and sudden exogenous shocks, which
we call Dirac shocks. This approach naturally leads to the notion of structural
(as opposed or complementary to temporal) forecast. Although structural
predictions are by far the most common way to test theories in the natural
sciences, they have been much less used in the social sciences. The Dirac shock
approach opens the way to testing structural predictions in the social
sciences. The examples reported here suggest that critical events are able to
reveal pre-existing ``cracks'' because they probe the social cohesion which is
an indicator and predictor of future evolution of the system, and in some cases
foreshadows a bifurcation. We complement our empirical work with numerical
simulations of the response function (``damage spreading'') to Dirac shocks in
the Sznajd model of consensus build-up. We quantify the slow relaxation of the
difference between perturbed and unperturbed systems, the conditions under
which the consensus is modified by the shock and the large variability from one
realization to another
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