726 research outputs found
A Clustering-Anonymity Approach for Trajectory Data Publishing Considering both Distance and Direction
Trajectory data contains rich spatio-temporal information of moving objects. Directly publishing it for mining and analysis will result in severe privacy disclosure problems. Most existing clustering-anonymity methods cluster trajectories according to either distance- or direction-based similarities, leading to a high information loss. To bridge this gap, in this paper, we present a clustering-anonymity approach considering both these two types of similarities. As trajectories may not be synchronized, we first design a trajectory synchronization algorithm to synchronize them. Then, two similarity metrics between trajectories are quantitatively defined, followed by a comprehensive one. Furthermore, a clustering-anonymity algorithm for trajectory data publishing with privacy-preserving is proposed. It groups trajectories into clusters according to the comprehensive similarity metric. These clusters are finally anonymized. Experimental results show that our algorithm is effective in preserving privacy with low information loss
Facile Fabrication of Ultrafine Copper Nanoparticles in Organic Solvent
A facile chemical reduction method has been developed to fabricate ultrafine copper nanoparticles whose sizes can be controlled down to ca. 1 nm by using poly(N-vinylpyrrolidone) (PVP) as the stabilizer and sodium borohyrdride as the reducing agent in an alkaline ethylene glycol (EG) solvent. Transmission electron microscopy (TEM) results and UV–vis absorption spectra demonstrated that the as-prepared particles were well monodispersed, mostly composed of pure metallic Cu nanocrystals and extremely stable over extended period of simply sealed storage
Rapid assessment of knowledge, attitudes, practices, and risk perception related to the prevention and control of Ebola virus disease in three communities of Sierra Leone
Questionnaire on Ebola knowledge, attitudes, practices, and risk perception in three communities of Sierra Leone, 2015. (DOCX 34 kb
The LAMOST Survey of Background Quasars in the Vicinity of the Andromeda and Triangulum Galaxies -- II. Results from the Commissioning Observations and the Pilot Surveys
We present new quasars discovered in the vicinity of the Andromeda and
Triangulum galaxies with the LAMOST during the 2010 and 2011 observational
seasons. Quasar candidates are selected based on the available SDSS, KPNO 4 m
telescope, XSTPS optical, and WISE near infrared photometric data. We present
509 new quasars discovered in a stripe of ~135 sq. deg from M31 to M33 along
the Giant Stellar Stream in the 2011 pilot survey datasets, and also 17 new
quasars discovered in an area of ~100 sq. deg that covers the central region
and the southeastern halo of M31 in the 2010 commissioning datasets. These 526
new quasars have i magnitudes ranging from 15.5 to 20.0, redshifts from 0.1 to
3.2. They represent a significant increase of the number of identified quasars
in the vicinity of M31 and M33. There are now 26, 62 and 139 known quasars in
this region of the sky with i magnitudes brighter than 17.0, 17.5 and 18.0
respectively, of which 5, 20 and 75 are newly-discovered. These bright quasars
provide an invaluable collection with which to probe the kinematics and
chemistry of the ISM/IGM in the Local Group of galaxies. A total of 93 quasars
are now known with locations within 2.5 deg of M31, of which 73 are newly
discovered. Tens of quasars are now known to be located behind the Giant
Stellar Stream, and hundreds behind the extended halo and its associated
substructures of M31. The much enlarged sample of known quasars in the vicinity
of M31 and M33 can potentially be utilized to construct a perfect astrometric
reference frame to measure the minute PMs of M31 and M33, along with the PMs of
substructures associated with the Local Group of galaxies. Those PMs are some
of the most fundamental properties of the Local Group.Comment: 26 pages, 6 figures, AJ accepte
Cutaneous immunoprofiles of three spotted fever group Rickettsia cases
Spotted fever group rickettsia (SFGR) can cause mild to fatal illness. The
early interaction between the host and rickettsia in skin is largely unknown, and the
pathogenesis of severe rickettsiosis remains an important topic. A surveillance of
SFGR infection by PCR of blood and skin biopsy specimens followed by sequencing
and immunohistochemical (IHC) detection was performed on patients with a recent
tick bite between 2013 and 2016. Humoral and cutaneous immunoprofiles were
evaluated in different SFGR cases by serum cytokine and chemokine detection, skin
IHC staining, and transcriptome sequencing (RNA-seq). A total of 111 SFGR cases
were identified, including 79 “Candidatus Rickettsia tarasevichiae,” 22 Rickettsia raoultii,
8 Rickettsia sibirica, and 2 Rickettsia heilongjiangensis cases. The sensitivity to detect
SFGR in skin biopsy specimens (9/24, 37.5%) was significantly higher than that
in blood samples (105/2,671, 3.9%) (P 0.05). As early as 1 day after the tick bite,
rickettsiae could be detected in the skin. R. sibirica infection was more severe than
“Ca. Rickettsia” and R. raoultii infections. Increased levels of serum interleukin-18 (IL-
18), IP10, and monokine induced by gamma interferon (MIG) and decreased levels of
IL-2 were observed in febrile patients infected with R. sibirica compared to those infected
with “Ca. Rickettsia.” RNA-seq and IHC staining could not discriminate between
SFGR-infected and uninfected tick bite skin lesions. However, the type I interferon
(IFN) response was differently expressed between R. sibirica and R. raoultii
infections at the cutaneous interface. It is concluded that skin biopsy specimens
were more reliable for the detection of SFGR infection in human patients although
the immunoprofile may be complicated by immunomodulators induced by the tick
bite.The Natural Science Foundation of China (81621005 and 81773492) and the State Key Research Development Program of China (2016YFC 1200301).https://iai.asm.orgam2020Veterinary Tropical Disease
Effects of dissipation on quantum phase transitions
We discuss the effect of dissipation on quantum phase transitions. In
particular we concentrate on the Superconductor to Insulator and Quantum-Hall
to Insulator transitions. By invoking a phenomenological parameter to
describe the coupling of the system to a continuum of degrees of freedom
representing the dissipative bath, we obtain new phase diagrams for the quantum
Hall and superconductor-insulator problems. Our main result is that, in
two-dimensions, the metallic phases observed in finite magnetic fields
(possibly also strictly zero field) are adiabatically deformable from one to
the other. This is plausible, as there is no broken symmetry which
differentiates them.Comment: 13 pages, 4 figure
JUNO Conceptual Design Report
The Jiangmen Underground Neutrino Observatory (JUNO) is proposed to determine
the neutrino mass hierarchy using an underground liquid scintillator detector.
It is located 53 km away from both Yangjiang and Taishan Nuclear Power Plants
in Guangdong, China. The experimental hall, spanning more than 50 meters, is
under a granite mountain of over 700 m overburden. Within six years of running,
the detection of reactor antineutrinos can resolve the neutrino mass hierarchy
at a confidence level of 3-4, and determine neutrino oscillation
parameters , , and to
an accuracy of better than 1%. The JUNO detector can be also used to study
terrestrial and extra-terrestrial neutrinos and new physics beyond the Standard
Model. The central detector contains 20,000 tons liquid scintillator with an
acrylic sphere of 35 m in diameter. 17,000 508-mm diameter PMTs with high
quantum efficiency provide 75% optical coverage. The current choice of
the liquid scintillator is: linear alkyl benzene (LAB) as the solvent, plus PPO
as the scintillation fluor and a wavelength-shifter (Bis-MSB). The number of
detected photoelectrons per MeV is larger than 1,100 and the energy resolution
is expected to be 3% at 1 MeV. The calibration system is designed to deploy
multiple sources to cover the entire energy range of reactor antineutrinos, and
to achieve a full-volume position coverage inside the detector. The veto system
is used for muon detection, muon induced background study and reduction. It
consists of a Water Cherenkov detector and a Top Tracker system. The readout
system, the detector control system and the offline system insure efficient and
stable data acquisition and processing.Comment: 328 pages, 211 figure
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