106 research outputs found
Effect of different plants on azo-dye wastewater bio-decolorization
AbstractTwo salt-tolerant plants (Medicago sativa L. and Sesbania cannabina Pers) as well as a kind of salt-tolerant azo-dye decolorization bacteria GTY (Gracilibacillus sp.GTY) were selected to treat acid red B or acid scarlet GR contaminated water. Results showed that Medicago sativa L. was more tolerant to the azo dyes and more helpful in promoting the azo-dye wastewater bio-decoloration than Sesbania cannabina Pers, but GTY density was higher in the root exudates of Sesbania cannabina Pers than that of Medicago sativa L. This indicated that the increase of GTY density only partially presented the azo-dye decolorization promoted by plants
5G Mobile Communications
This book provides a comprehensive overview of the emerging technologies for next-generation 5G mobile communications, with insights into the long-term future of 5G. Written by international leading experts on the subject, this contributed volume covers a wide range of technologies, research results, and networking methods. Key enabling technologies for 5G systems include, but are not limited to, millimeter-wave communications, massive MIMO technology and non-orthogonal multiple access.
5G will herald an even greater rise in the prominence of mobile access based upon both human-centric and machine-centric networks. Compared with existing 4G communications systems, unprecedented numbers of smart and heterogeneous wireless devices will be accessing future 5G mobile systems. As a result, a new paradigm shift is required to deal with challenges on explosively growing requirements in mobile data traffic volume (1000x), number of connected devices (10–100x), typical end-user data rate (10–100x), and device/network lifetime (10x). Achieving these ambitious goals calls for revolutionary candidate technologies in future 5G mobile systems.
Designed for researchers and professionals involved with networks and communication systems, 5G Mobile Communications is a straightforward, easy-to-read analysis of the possibilities of 5G systems
GPUSCAN:Efficient Structural Graph Clustering on GPUs
Structural clustering is one of the most popular graph clustering methods,
which has achieved great performance improvement by utilizing GPUs. Even
though, the state-of-the-art GPU-based structural clustering algorithm,
GPUSCAN, still suffers from efficiency issues since lots of extra costs are
introduced for parallelization. Moreover, GPUSCAN assumes that the graph is
resident in the GPU memory. However, the GPU memory capacity is limited
currently while many real-world graphs are big and cannot fit in the GPU
memory, which makes GPUSCAN unable to handle large graphs. Motivated by this,
we present a new GPU-based structural clustering algorithm, GPUSCAN++, in this
paper. To address the efficiency issue, we propose a new progressive clustering
method tailored for GPUs that not only avoid high parallelization costs but
also fully exploits the computing resources of GPUs. To address the GPU memory
limitation issue, we propose a partition-based algorithm for structural
clustering that can process large graphs with limited GPU memory. We conduct
experiments on real graphs, and the experimental results demonstrate that our
algorithm can achieve up to 168 times speedup compared with the
state-of-the-art GPU-based algorithm when the graph can be resident in the GPU
memory. Moreover, our algorithm is scalable to handle large graphs. As an
example, our algorithm can finish the structural clustering on a graph with 1.8
billion edges using less than 2 GB GPU memory
Aggregate Interference Modeling in Cognitive Radio Networks with Power and Contention Control
In this paper, we present an interference model for cognitive radio (CR)
networks employing power control, contention control or hybrid power/contention
control schemes. For the first case, a power control scheme is proposed to
govern the transmission power of a CR node. For the second one, a contention
control scheme at the media access control (MAC) layer, based on carrier sense
multiple access with collision avoidance (CSMA/CA), is proposed to coordinate
the operation of CR nodes with transmission requests. The probability density
functions of the interference received at a primary receiver from a CR network
are first derived numerically for these two cases. For the hybrid case, where
power and contention controls are jointly adopted by a CR node to govern its
transmission, the interference is analyzed and compared with that of the first
two schemes by simulations. Then, the interference distributions under the
first two control schemes are fitted by log-normal distributions with greatly
reduced complexity. Moreover, the effect of a hidden primary receiver on the
interference experienced at the receiver is investigated. It is demonstrated
that both power and contention controls are effective approaches to alleviate
the interference caused by CR networks. Some in-depth analysis of the impact of
key parameters on the interference of CR networks is given via numerical
studies as well.Comment: 24 pages, 8 figures, submitted to IEEE Trans. Communications in July
201
Collective Entity Alignment via Adaptive Features
Entity alignment (EA) identifies entities that refer to the same real-world
object but locate in different knowledge graphs (KGs), and has been harnessed
for KG construction and integration. When generating EA results, current
solutions treat entities independently and fail to take into account the
interdependence between entities. To fill this gap, we propose a collective EA
framework. We first employ three representative features, i.e., structural,
semantic and string signals, which are adapted to capture different aspects of
the similarity between entities in heterogeneous KGs. In order to make
collective EA decisions, we formulate EA as the classical stable matching
problem, which is further effectively solved by deferred acceptance algorithm.
Our proposal is evaluated on both cross-lingual and mono-lingual EA benchmarks
against state-of-the-art solutions, and the empirical results verify its
effectiveness and superiority.Comment: ICDE2
Energy-Spectral Efficiency Trade-Off in Virtual MIMO Cellular Systems
Virtual multiple-input multiple-output (V-MIMO) technology promises significant performance enhancements to cellular systems in terms of spectral efficiency (SE) and energy efficiency (EE). How these two conflicting metrics scale up in large cellular V-MIMO networks is unclear. This paper studies the EE-SE trade-off of the uplink of a multi-user cellular V-MIMO system with decode-and-forward type protocols. We first express the trade-off in an implicit function and further derive closed-form formulas of the trade-off in low and high SE regimes. Unlike conventional MIMO systems, the EE-SE trade-off of the V-MIMO system is shown to be susceptible to many factors including protocol design (e.g., resource allocation) and scenario characteristics (e.g., user density). Focusing on the medium and high SE regimes, we propose a heuristic resource allocation algorithm to optimize the EE-SE trade-off. The fundamental performance limits of the optimized V-MIMO system are subsequently investigated and compared with conventional MIMO systems in different scenarios. Numerical results reveal a surprisingly chaotic behavior of V-MIMO systems when the user density scales up. Our analysis indicates that low frequency reuse factor, adaptive resource allocation, and user density control are critical to harness the full benefits of cellular V-MIMO systems.</p
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