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Performance bounds provide a solid theoretical ground for comparing different localization methods. Similarly to the actual performance, they depend on two factors, namely the accuracy of the available data that are used for localization and the geometry of the network. While the impact of the accuracy of the available data has been studied extensively, the literature on the impact of network geometry...
In a downlink transmission, users can benefit from the high capacity gain achieved by transmitting independent data streams from multiple antennas to multiple users sharing the same physical time-frequency resources. This technique is known as multiuser MIMO (MU-MIMO). However, performance of MU-MIMO is sensitive towards propagation imperfections, such as time dispersion and inter-stream interference...
Polarized MIMO systems are an efficient solution for reducing inter-antenna correlation while maintaining compact terminal size. In this paper, a time-variant statistical channel model is proposed for tri-polarized antenna systems. The model is based on a coherent and a scattered component, where each component includes inter-channel correlation and cross-polar discriminations. The temporal variations...
In the bistatic radar, it is important to suppress the undesired signals such as the direct propagated signal from transmitter and its multipath components. Conventionally, the suppression method by subtracting the replicas of the undesired signals is often used. However, it requires the precise delay times of the undesired signals. In this paper we propose a new method to detect the target without...
In the Web 2.0 era, users share and discover interesting content via a network of relationships created in various social networking or content sharing sites. They can become for example contacts, followers or friends and express their appreciation of specific content uploaded by their peers by faving, retweeting or liking them depending on whether they are in Flickr, Twitter or Facebook respectively...
Social capital broadly refers to the opportunities an individual has by being part of a network of relationships. Recently organizations started deploying internal Enterprise 2.0 platforms and Social Network Sites (SNS) to improve how employees collaborate and work. In this paper we report our analysis of the relationships between social capital and the use of a SNS in a research institute. Data collected...
In identifying communities in the online environment most approaches consider as the basic tie that connects social actors together some form of direct contact, such as through communication. Other approaches use surrogates for direct ties including copresense, cooccurrence, or structural equivalence. In contrast, this paper focuses on semantic equivalence among social actors, regardless of their...
Many relationships naturally come in a bipartite setting: authors that write articles, proteins that interact with genes, or customers that buy, rent or rate products. Often we are interested in the clustering behavior of one side of the graph, i.e., in finding groups of similar articles or products. To find these clusters, a one-mode projection is classically applied, which results in a normal graph...
Management of traffic incident is an essential part of emergency management. Impact analysis of incident becomes more and more important in the operation of Intelligent Traffic System. This paper uses flow data collected from loop detectors to analyze the impact of incident in urban traffic system. A complex network model using correlation coefficient as the edge weight is constructed. Then, the random...
In this paper, factor analysis is applied on a set of data that was collected to study the effectiveness of 58 different agile practices. The analysis extracted 15 factors, each was associated with a list of practices. These factors with the associated practices can be used as a guide for agile process improvement. Correlations between the extracted factors were calculated, and the significant correlation...
This paper explores website link structure considering websites as interconnected graphs and analyzing their features as a social network. Factor Analysis provides the statistical methodology to adequately extract the main website profiles in terms of their internal structure. However, due to the large number of indicators, a genetic search of their optimum number is proposed, and applied to a case...
Researched and developed the software system of Information Management and Decision Support System of the hidden danger troubleshooting of Coal Mine. By using the technology of collaborative software to realize fast circulation of information, dynamic tracking, rapid feedback, and closed-loop management of transaction processing for the hidden danger, and by applying the technology of data mining,...
The vertex-betweenness centrality index is an essential measurement for analyzing social networks, but the computation time is excessive. At present, the fastest algorithm, proposed by Brandes in 2001, requires O(|V| |E|) time, which is computationally intractable for real-world social networks that usually contain millions of nodes and edges. In this paper, we propose a fast and accurate algorithm...
Over the last decade blogs became an important part of the Web, where people can announce anything that is on their mind. Due to their high popularity blogs have great potential to mine public opinions regarding products. Such knowledge is very valuable as it could be used to adjust marketing campaigns or advertisement of products accordingly. In this paper we investigate how the blogosphere can be...
Community detection consists in searching cohesive subgroups in complex networks. It has recently become one of the domain pivotal questions for scientists in many different fields where networks are used as modeling tools. Algorithms performing community detection are usually tested on real, but also on artificial networks, the former being costly and difficult to obtain. In this context, being able...
Copula function is a function that links joint distribution function of random vectors and its corresponding components marginal distribution function. It is an important tool to describe the structure relationship between many financial markets. With using the Copula function to construct the joint distribution function, it will not be limited by the marginal distribution function, instead, the marginal...
In this paper we present a statistically tested evidence about how quality and success rate are correlated with variables reflecting the organization and aspects of its project's governance, namely retrospectives and metrics. The results presented in this paper are based on the Agile Projects Governance Survey that collected 129 responses. This paper discuss the deep analysis of this survey, and the...
at the present time, the increase of e-mail spam are heavy to cumber and the spam are vastly spread. These spams cause various problems to the Internet users, such as full incoming mailbox, and wasting time. Therefore, tremendous methods have been proposed but most of them have limitation in the mapping feature and processing time. This paper proposed a method that can detect a set of image e-mail...
As a large-scale global parallel file system, Lustre file system plays a key role in High Performance Computing (HPC) system, and the potential performance of such systems can be difficult to predict because the potential impact to application performance is not clearly understood. It is important to gain insights into the deliverable Lustre file system IO efficiency. In order to gain a good understanding...
A long lasting myth of formal methods is that they are difficult to learn and expensive to apply. This paper reports a controlled experiment to test if this myth is true or false in the context of writing algebraic formal specifications. The experiment shows that writing algebraic specifications for software components can be learnt by ordinary university students. It does not heavily depend on mathematical...
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