2,808 research outputs found
Leading Undergraduate Students to Big Data Generation
People are facing a flood of data today. Data are being collected at
unprecedented scale in many areas, such as networking, image processing,
virtualization, scientific computation, and algorithms. The huge data nowadays
are called Big Data. Big data is an all encompassing term for any collection of
data sets so large and complex that it becomes difficult to process them using
traditional data processing applications. In this article, the authors present
a unique way which uses network simulator and tools of image processing to
train students abilities to learn, analyze, manipulate, and apply Big Data.
Thus they develop students handson abilities on Big Data and their critical
thinking abilities. The authors used novel image based rendering algorithm with
user intervention to generate realistic 3D virtual world. The learning outcomes
are significant
Improving Routing Efficiency through Intermediate Target Based Geographic Routing
The greedy strategy of geographical routing may cause the local minimum
problem when there is a hole in the routing area. It depends on other
strategies such as perimeter routing to find a detour path, which can be long
and result in inefficiency of the routing protocol. In this paper, we propose a
new approach called Intermediate Target based Geographic Routing (ITGR) to
solve the long detour path problem. The basic idea is to use previous
experience to determine the destination areas that are shaded by the holes. The
novelty of the approach is that a single forwarding path can be used to
determine a shaded area that may cover many destination nodes. We design an
efficient method for the source to find out whether a destination node belongs
to a shaded area. The source then selects an intermediate node as the tentative
target and greedily forwards packets to it, which in turn forwards the packet
to the final destination by greedy routing. ITGR can combine multiple shaded
areas to improve the efficiency of representation and routing. We perform
simulations and demonstrate that ITGR significantly reduces the routing path
length, compared with existing geographic routing protocols
Document Clustering Based On Max-Correntropy Non-Negative Matrix Factorization
Nonnegative matrix factorization (NMF) has been successfully applied to many
areas for classification and clustering. Commonly-used NMF algorithms mainly
target on minimizing the distance or Kullback-Leibler (KL) divergence,
which may not be suitable for nonlinear case. In this paper, we propose a new
decomposition method by maximizing the correntropy between the original and the
product of two low-rank matrices for document clustering. This method also
allows us to learn the new basis vectors of the semantic feature space from the
data. To our knowledge, we haven't seen any work has been done by maximizing
correntropy in NMF to cluster high dimensional document data. Our experiment
results show the supremacy of our proposed method over other variants of NMF
algorithm on Reuters21578 and TDT2 databasets.Comment: International Conference of Machine Learning and Cybernetics (ICMLC)
201
RESOURCE ALLOCATION AND EFFICIENT ROUTING IN WIRELESS NETWORKS
In wireless networks, devices (nodes) are connected by wireless links. An important issue is to set up high quality (high bandwidth) and efficient routing paths when one node wants to send packets to other nodes. Resource allocation is the foundation to guarantee high quality connections. In addition, it is critical to handle void areas in order to set up detour-free paths. Moreover, fast message broadcasting is essential in mobile wireless networks. Thus, my research includes dynamic channel allocation in wireless mesh networks, geographic routing in Ad Hoc networks, and message broadcasting in vehicular networks.
The quality of connections in a wireless mesh network can be improved by equip- ping mesh nodes with multi-radios capable of tuning to non-overlapping channels. The essential problem is how to allocate channels to these multi-radio nodes. We develop a new bipartite-graph based channel allocation algorithm, which can improve bandwidth utilization and lower the possibility of starvation. Geographic routing in Ad Hoc networks is scalable and normally loop-free. However, traditional routing protocols often result in long detour paths when holes exist. We propose a routing protocol-Intermediate Target based Geographic Routing (ITGR) to solve this problem. The novelty is that a single forwarding path can be used to reduce the lengths of many future routing paths. We also develop a protocol called Hole Detection and Adaptive Geographic Routing, which identifies the holes efficiently by comparing the length of a routing path with the Euclidean distance between a pair of nodes. We then set up the shortest path based on it. Vehicles play an important role in our daily life. During inter-vehicle communication, it is essential that emergency information can be broadcast to surrounding vehicles quickly. We devise an approach that can find the best re-broadcasting node and propagate the message as fast as possible
Facile synthesis and enhanced visible light photocatalytic activity of N and Zr co-doped TiO2 nanostructures from nanotubular titanic acid precursors
Zr/N co-doped TiO2 nanostructures were successfully synthesized using
nanotubular titanic acid (NTA) as precursors by a facile wet chemical route and
subsequent calcination. These Zr/N-doped TiO2 nanostructures made by NTA
precursors show significantly enhanced visible light absorption and much higher
photocatalytic performance than the Zr/N-doped P25 TiO2 nanoparticles. Impacts
of Zr/N co-doping on the morphologies, optical properties, and photocatalytic
activities of the NTA precursor-based TiO2 were thoroughly investigated. The
origin of the enhanced visible light photocatalytic activity is discussed in
detail.Comment: 8 pages, 7 figure
Driving Scene Perception Network: Real-time Joint Detection, Depth Estimation and Semantic Segmentation
As the demand for enabling high-level autonomous driving has increased in
recent years and visual perception is one of the critical features to enable
fully autonomous driving, in this paper, we introduce an efficient approach for
simultaneous object detection, depth estimation and pixel-level semantic
segmentation using a shared convolutional architecture. The proposed network
model, which we named Driving Scene Perception Network (DSPNet), uses
multi-level feature maps and multi-task learning to improve the accuracy and
efficiency of object detection, depth estimation and image segmentation tasks
from a single input image. Hence, the resulting network model uses less than
850 MiB of GPU memory and achieves 14.0 fps on NVIDIA GeForce GTX 1080 with a
1024x512 input image, and both precision and efficiency have been improved over
combination of single tasks.Comment: 9 pages, 7 figures, WACV'1
Enhancement of Visible-Light-Induced Photocurrent and Photocatalytic Activity of V and N Codoped TiO2 Nanotube Array Films
Highly ordered TiO2 nanotube arrays (TNAs) codoped with V and N were
synthesized by electrochemical anodization in association with hydrothermal
treatment. The samples were characterized by field emission scanning electron
microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The
photocurrent and photocatalytic activity of codoped TiO2 nanotube arrays were
investigated under visible light irradiation. Moreover, the production of
hydroxyl radicals on the surface of visible light-irradiated samples is
detected by a photoluminescence technique using terephthalic acid (TA) as a
probe molecule. It was found that the V+N co-doped TiO2 nanotube arrays showed
remarkably enhanced photocurrent and photocatalytic activity than undoped
sample due to the V and N codoping.Comment: 15 Pages, 6 figure
An Immersive Telepresence System using RGB-D Sensors and Head Mounted Display
We present a tele-immersive system that enables people to interact with each
other in a virtual world using body gestures in addition to verbal
communication. Beyond the obvious applications, including general online
conversations and gaming, we hypothesize that our proposed system would be
particularly beneficial to education by offering rich visual contents and
interactivity. One distinct feature is the integration of egocentric pose
recognition that allows participants to use their gestures to demonstrate and
manipulate virtual objects simultaneously. This functionality enables the
instructor to ef- fectively and efficiently explain and illustrate complex
concepts or sophisticated problems in an intuitive manner. The highly
interactive and flexible environment can capture and sustain more student
attention than the traditional classroom setting and, thus, delivers a
compelling experience to the students. Our main focus here is to investigate
possible solutions for the system design and implementation and devise
strategies for fast, efficient computation suitable for visual data processing
and network transmission. We describe the technique and experiments in details
and provide quantitative performance results, demonstrating our system can be
run comfortably and reliably for different application scenarios. Our
preliminary results are promising and demonstrate the potential for more
compelling directions in cyberlearning.Comment: IEEE International Symposium on Multimedia 201
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