Social multimedia content had an unprecedented increasing trend in recent years, and receiving a number of research attentions. Images, an exceedingly expressive form of social multimedia, can be widely seen in news r...
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Social multimedia content had an unprecedented increasing trend in recent years, and receiving a number of research attentions. Images, an exceedingly expressive form of social multimedia, can be widely seen in news report for social emergency. Among the vast number of images for social emergency are many repurposed images, that is, variants not interpreted as what the original images express. Such repurposed images appear in many online pages and may mislead the public. This make it being an interesting and challenging task to identify whether an image is repurposed. We propose a novel framework, called SOFC, to identify the repurposed images. A SIFT-based identical parts finding algorithm is used to find and align all potential identical blocks in the repurposed images and the original images. We then compute the similarity of the potential identical blocks by implementing an object-based likelihood measuring algorithm, to determine whether these blocks are identical in the two images. Finally, the effectiveness of the proposed identification method is validated by experiments on a image set of real social emergency.
A promising P2P application, P2P-TV, has attracted hundreds of thousands of Chinese viewers. These viewers who are located in different regions represent groups with distinct cultures. However, little existing researc...
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A promising P2P application, P2P-TV, has attracted hundreds of thousands of Chinese viewers. These viewers who are located in different regions represent groups with distinct cultures. However, little existing research has provided sufficient insights into the societal impact of P2P-TV systems, from the viewpoint of geographic distribution of viewers. In this paper, we analyze geographic distribution of viewers of three most popular P2P-TV systems simultaneously, PPLive, PPStream and UUSee. With more than 20 GB worth of log data from three different P2P-TV systems, we have completed a thorough investigation of geographic distribution of viewers. We also seek to explore the potential correlation between viewer population density and economic development level and find that there is indeed a highly negative correlation between them.
Because the structure and function of a high-rise building is complex and the density of occupants in it is high, fire safety is still a worldwide difficult problem. Safety and timely evacuation is an important issue ...
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Sina-Microblog, the earliest and biggest microblogging service in China, has become one of the most popular media in information propagation. In order to gain insights into the topological and information diffusing ch...
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Sina-Microblog, the earliest and biggest microblogging service in China, has become one of the most popular media in information propagation. In order to gain insights into the topological and information diffusing characteristics of microblogging network in China, we crawled Sina-Microblog for about 3 months and obtain the trace of its topology and topics. Compared with other online social networks, our measurement study shows a number of interesting findings. Our data suggests that Sina-Microblog network has apparent small-world effect and scale-free characteristic, specially, the outdegree distribution appears to have multiple separate power-law regimes with different exponents. We also observe the overlay graph of Sina-Microblog represents assortative mixing pattern and weak correlation of indegree and outdegree. Moreover, by constructing the cascades of different topics, our data suggests that the distribution of cascades size follows a power-law and heavy-tailed property with the slope approximately -2, and the common motifs of cascades with different topics are very similar, above 93% of them are isolated nodes. In order to find the formative motivity of hot cascades, we find that they always evolve to the structures like `star pattern' and `two-polar pattern', which are mainly due to the indegree of participating nodes, and are also correlated with the content of tweet.
With the advantage of simulating the details of a transportation system, the “microsimulation” of a traffic system has long been a hot topic in the Intelligent Transportation systems (ITS) research. The Cellular Aut...
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With the advantage of simulating the details of a transportation system, the “microsimulation” of a traffic system has long been a hot topic in the Intelligent Transportation systems (ITS) research. The Cellular Automata (CA) and the Multi-Agent System (MAS) modeling are two typical methods for the traffic microsimulation. However, the computing burden for the microsimulation and the optimization based on it is usually very heavy. In recent years the Graphics Processing Units (GPUs) have been applied successfully in many areas for parallel computing. Compared with the traditional CPU cluster, GPU has an obvious advantage of low cost of hardware and electricity consumption. In this paper we build an MAS model for a road network of four signalized intersections and we use a Genetic Algorithm (GA) to optimize the traffic signal timing with the objective of maximizing the number of the vehicles leaving the network in a given period of time. Both the simulation and the optimization are accelerated by GPU and a speedup by a factor of 195 is obtained. In the future we will extend the work to large scale road networks.
Because the structure and function of a high-rise building is complex and the density of occupants in it is high, fire safety is still a worldwide difficult problem. Safety and timely evacuation is an important issue ...
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Because the structure and function of a high-rise building is complex and the density of occupants in it is high, fire safety is still a worldwide difficult problem. Safety and timely evacuation is an important issue under fire in the high-rise buildings. Because it is impossible in fact to do experiments about fire safety evacuation in high-rise buildings, in this paper, a research framework based on the artificial system, computationalexperiments, and parallel excution (ACP) theory is proposed. First, an evacuation process is considered to compose of two stages including pre-evacuation stage and evacuation stage. Second, artifical men with recognition functions based agent technology is proposed. Finally, computationalexperiments are designed by using an orthogonal experiment table, and experiment procedure of pre-evacuation stage is given. The idea of systimatic research about the influence of fire control facilities to evacuation is also proposed.
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