West Virginia University

About: West Virginia University is a(n) education organization based out in Morgantown, West Virginia, United States. It is known for research contribution in the topic(s): Population & Poison control. The organization has 25632 authors who have published 48308 publication(s) receiving 1343934 citation(s). The organization is also known as: WVU & West Virginia University, WVU.

Observation of Gravitational Waves from a Binary Black Hole Merger

Abstract: On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of $1.0 \times 10^{-21}$. It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203 000 years, equivalent to a significance greater than 5.1 {\sigma}. The source lies at a luminosity distance of $410^{+160}_{-180}$ Mpc corresponding to a redshift $z = 0.09^{+0.03}_{-0.04}$. In the source frame, the initial black hole masses are $36^{+5}_{-4} M_\odot$ and $29^{+4}_{-4} M_\odot$, and the final black hole mass is $62^{+4}_{-4} M_\odot$, with $3.0^{+0.5}_{-0.5} M_\odot c^2$ radiated in gravitational waves. All uncertainties define 90% credible intervals.These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of gravitational waves and the first observation of a binary black hole merger.

GW170817: observation of gravitational waves from a binary neutron star inspiral

Abstract: On August 17, 2017 at 12∶41:04 UTC the Advanced LIGO and Advanced Virgo gravitational-wave detectors made their first observation of a binary neutron star inspiral. The signal, GW170817, was detected with a combined signal-to-noise ratio of 32.4 and a false-alarm-rate estimate of less than one per 8.0×10^{4} years. We infer the component masses of the binary to be between 0.86 and 2.26 M_{⊙}, in agreement with masses of known neutron stars. Restricting the component spins to the range inferred in binary neutron stars, we find the component masses to be in the range 1.17-1.60 M_{⊙}, with the total mass of the system 2.74_{-0.01}^{+0.04}M_{⊙}. The source was localized within a sky region of 28 deg^{2} (90% probability) and had a luminosity distance of 40_{-14}^{+8} Mpc, the closest and most precisely localized gravitational-wave signal yet. The association with the γ-ray burst GRB 170817A, detected by Fermi-GBM 1.7 s after the coalescence, corroborates the hypothesis of a neutron star merger and provides the first direct evidence of a link between these mergers and short γ-ray bursts. Subsequent identification of transient counterparts across the electromagnetic spectrum in the same location further supports the interpretation of this event as a neutron star merger. This unprecedented joint gravitational and electromagnetic observation provides insight into astrophysics, dense matter, gravitation, and cosmology.

Transformational leader behaviors and their effects on followers' trust in leader, satisfaction, and organizational citizenship behaviors

Abstract: This study examines the impact of transformational leader behaviors on organizational citizenship behaviors, and the potential mediating role played by subordinates' trust and satisfaction in that process. Measures of six transformational leader behaviors (Articulating a Vision, Providing an Appropriate Model, Fostering the Acceptance of Group Goals, High Performance Expectations, Individualized Support, and Intellectual Stimulation), one transactional leader behavior (Contingent Reward Behavior), employees' trust in their leader, and satisfaction were obtained from 988 exempt employees of a large petrochemical company. Matching evaluations of five citizenship behaviors of these employees (Altruism, Conscientiousness, Courtesy, Civic Virtue, and Sportsmanship) were obtained from their supervisors. In order to determine whether transformational behaviors augment the impact of transactional behaviors, their effects on followers' trust, satisfaction, and citizenship behaviors were examined in the context of the effect of transactional leader behaviors on these same variables. The results indicate that the effects of the transformational leader behaviors on citizenship behaviors are indirect, rather than direct, in that they are mediated by followers' trust in their leaders. Moreover, these results were found not to be wholly attributable to the effects of common method biases. The implications of these findings for future research on transformational leader behaviors, trust, and organizational citizenship behavior are then discussed.

An introduction to biometric recognition

Abstract: A wide variety of systems requires reliable personal recognition schemes to either confirm or determine the identity of an individual requesting their services. The purpose of such schemes is to ensure that the rendered services are accessed only by a legitimate user and no one else. Examples of such applications include secure access to buildings, computer systems, laptops, cellular phones, and ATMs. In the absence of robust personal recognition schemes, these systems are vulnerable to the wiles of an impostor. Biometric recognition, or, simply, biometrics, refers to the automatic recognition of individuals based on their physiological and/or behavioral characteristics. By using biometrics, it is possible to confirm or establish an individual's identity based on "who she is", rather than by "what she possesses" (e.g., an ID card) or "what she remembers" (e.g., a password). We give a brief overview of the field of biometrics and summarize some of its advantages, disadvantages, strengths, limitations, and related privacy concerns.

An Introduction to Applied Geostatistics

Abstract: Keywords: Krigeage ; continuite spatiale ; variogramme ; incertitudes ; anisotropie ; interpolation Reference Record created on 2005-06-20, modified on 2011-09-01