6,990 research outputs found
Reliable Energy-Efficient Routing Algorithm for Vehicle-Assisted Wireless Ad-Hoc Networks
We investigate the design of the optimal routing path in a moving vehicles
involved the internet of things (IoT). In our model, jammers exist that may
interfere with the information exchange between wireless nodes, leading to
worsened quality of service (QoS) in communications. In addition, the transmit
power of each battery-equipped node is constrained to save energy. We propose a
three-step optimal routing path algorithm for reliable and energy-efficient
communications. Moreover, results show that with the assistance of moving
vehicles, the total energy consumed can be reduced to a large extend. We also
study the impact on the optimal routing path design and energy consumption
which is caused by path loss, maximum transmit power constrain, QoS
requirement, etc.Comment: 6 pages, 5 figures, rejected by IEEE Globecom 2017,resubmit to IEEE
WCNC 201
Molecular Dynamics Simulation of Macromolecules Using Graphics Processing Unit
Molecular dynamics (MD) simulation is a powerful computational tool to study
the behavior of macromolecular systems. But many simulations of this field are
limited in spatial or temporal scale by the available computational resource.
In recent years, graphics processing unit (GPU) provides unprecedented
computational power for scientific applications. Many MD algorithms suit with
the multithread nature of GPU. In this paper, MD algorithms for macromolecular
systems that run entirely on GPU are presented. Compared to the MD simulation
with free software GROMACS on a single CPU core, our codes achieve about 10
times speed-up on a single GPU. For validation, we have performed MD
simulations of polymer crystallization on GPU, and the results observed
perfectly agree with computations on CPU. Therefore, our single GPU codes have
already provided an inexpensive alternative for macromolecular simulations on
traditional CPU clusters and they can also be used as a basis to develop
parallel GPU programs to further speedup the computations.Comment: 21 pages, 16 figure
Discovery of the transient magnetar 3XMM J185246.6+003317 near supernova remnant Kesteven 79 with XMM-Newton
We report the serendipitous discovery with XMM-Newton that 3XMM
J185246.6+003317 is an 11.56 s X-ray pulsar located 1' away from the southern
boundary of supernova remnant Kes 79. The spin-down rate of 3XMM
J185246.6+003317 is s s, which, together with the
long period P=11.558714(2) s, indicates a dipolar surface magnetic field of
Myr, and a spin-down
luminosity of erg s. The X-ray spectrum of the
source is best-fitted with a resonant Compton scattering model, and can be also
adequately described by a blackbody model. The observations covering a seven
month span from 2008 to 2009 show variations in the spectral properties of the
source, with the luminosity decreasing from erg s to
erg s, along with a decrease of the blackbody
temperature from keV to keV. The X-ray luminosity
of the source is higher than its spin-down luminosity, ruling out rotation as a
power source. The combined timing and spectral properties, the non-detection of
any optical or infrared counterpart, together with the lack of detection of the
source in archival X-ray data prior to the 2008 XMM-Newton observation, point
to this source being a newly discovered transient low-B magnetar undergoing an
outburst decay during the XMM-Newton observations. The non-detection by Chandra
in 2001 sets an upper limit erg s to the quiescent
luminosity of 3XMM J185246.6+003317. Its period is the longest among currently
known transient magnetars. The foreground absorption toward 3XMM
J185246.6+003317 is similar to that of Kes 79, suggesting a similar distance of
7.1 kpc.Comment: 7 pages, 4 figures, 1 table; updated to match the published versio
On the Generation of Medical Question-Answer Pairs
Question answering (QA) has achieved promising progress recently. However,
answering a question in real-world scenarios like the medical domain is still
challenging, due to the requirement of external knowledge and the insufficient
quantity of high-quality training data. In the light of these challenges, we
study the task of generating medical QA pairs in this paper. With the insight
that each medical question can be considered as a sample from the latent
distribution of questions given answers, we propose an automated medical QA
pair generation framework, consisting of an unsupervised key phrase detector
that explores unstructured material for validity, and a generator that involves
a multi-pass decoder to integrate structural knowledge for diversity. A series
of experiments have been conducted on a real-world dataset collected from the
National Medical Licensing Examination of China. Both automatic evaluation and
human annotation demonstrate the effectiveness of the proposed method. Further
investigation shows that, by incorporating the generated QA pairs for training,
significant improvement in terms of accuracy can be achieved for the
examination QA system.Comment: AAAI 202
4-(1H-Tetrazol-5-yl)-1H-indole
There are two molecules with similar configurations in the asymmetric unit of the title compound, C9H7N5, which are linked by intermolecular N—H⋯N hydrogen bonds into chains with graph-set motif C
2
2(8) along the b axis. The indole core has the expected planar geometry in the two molecules, with a maximum deviation of 0.008 (8) Å from the least-squares plane defined by the nine constituent atoms, and the dihedral angles between the indole and tetrazole rings are similar [42.4 (2) and 42.7 (2)°]
Effects of Rh-endostar in Combination with Radiotherapy on Rats with Lung Cancer
Background and objective Radiation sensitivity is closely related to tissue oxygen, and rh-endostatin can induce the high level of oxygen content in tumor by "normalizing" tumor angiogenesis which is associated with radiotherapy sensitivity. The aim of this study is to observe the effect of combination of radiotherapy with rh-endostatin in the rats with lung cancer. Methods Immediate lewis cancerous ascetic injection method was used to make rats tumors bearing model, then the rats was divided into four groups randomly: group A was treated with saline; group B was treated with rh-endostatin; group C was treated with irradiation and group D was treated with rh-endostatin and irradiation. After all rats were treated, inhibition rates and the tumor growth curve were calculated. Immunohistochemisty was adopted to check the expressions of vascular endothelial growth factor (VEGF) and microvessel density (MVD). Results Compared with group A, the growth rates of the tumors in the other group were obviously slower, and the tumor weights were significantly different form group A (P<0.05). Compared with the other groups, the tumor weights of group D were obviously reduced (P<0.05). Compared with group A, VEGF and MVD of other three groups were reduced (P<0.05), and group D were significantly cut down. Conclusion Combination with radiotherapy and rh-endostatin could inhibit the lung cancer significantly in rats. The possible mechanisms are to decrease the expression of VEGF and inhibit the production of angiogenesis
Analytical Multi-Scale Methodology for Fluidization Systems - Retrospect and Prospect
Understanding the spatio-temporal multi-scale structure of fluidization is a challenging problem. This presentation reviews our 20-year efforts on this subject, showing the roadmap that has gradually evolved from a simple idea to a systematic methodology inclusive of subsidiary, related systems and industrial applications. The strategy of establishing stability conditions through analyses of the compromise between dominant mechanisms is emphasized. The presentation concludes with prospects for further theoretical explorations and industrial applications
Graphene-enhanced visible-light photocatalysis of large-sized CdS particles for wastewater treatment
The hybrid composites of graphene decorated by large-sized CdS particles (G/M-CdS) were prepared by a one-pot solvothermal route in which the reduction of graphite oxide into graphene was accompanied by the generation of microsized CdS particles. The structure and composition of the obtained nanocomposites were studied by means of X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The CdS particles with the average sizes of approximately 640 nm were formed on graphene sheets. The as-prepared composite was used as adsorbent to remove dye from wastewater using the organic dye Rhodamine B as the adsorbate. The G/M-CdS composite reveals a high photodegradation rate under visible light irradiation. Our results demonstrate that the G/M-CdS is very promising for removing organic dyes from wastewater
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