ppxscal/embedding_network huggingface dataset:
Improving the accuracy and efficiency of result retrieval in peer-to-peer networks
Authors: Linh T. Nguyen
Venue:  (2009)

Searching techniques of centralized search engines are not directly applicable to peer-to-peer (P2P) networks due to the dynamic and distributed characteristics of peers and shared data. As searching in P2P networks involves data transfer among peers, it is important to maintain the accuracy of search results without sacrificing the network bandwidth. We propose methods to improve each of the three stages of searching in P2P networks, namely result ranking, result retrieval, and query routing. Result ranking in P2P networks is ineffective because results are poorly described by a few keywords. We develop a metadata probing technique that allows us to enrich the metadata of the returned results. Our technique is based on the fact that peers' contents overlap, and each peer independently describes its own shared content (i.e., the same file might have different description on different peers). As more metadata from other peers are retrieved, result ranking performance is improved by up to 15%. Result retrieval in P2P networks suffers from the word mismatch problem: if a short description of a relevant file does not contain all query keywords, it will not be returned to the querying peer. To allow more relevant results to be returned, we relax the requirement of returning only results that contain all query keywords by replacing the query by one of its sub-queries (i.e., masking out one or more query keywords). Our query masking technique improves ranking performance up to 40%. Query routing in P2P networks aims to forward queries only to peers that have the answers. Poorly described peer contents make query routing inefficient. We propose to enhance peer content summaries, without affecting the scalability of the network. Our method is based on partitioning the shared contents into a number of groups, and representing each group separately. We develop a theoretical cost model and a cost based distance function to guide the partitioning process. Our technique eliminates up to 94% of erroneously routed queries for unstructured P2P networks, and reduces the query processing cost of structured P2P networks by up to 73%. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Influence of computer mediated communication on social capital: a disaggregated approach
Authors: Israr Qureshi
Venue:  (2009)

In a knowledge driven firm, who you know and how they can help you has become as important as what you know. This realization has brought social interactions to the center of organizational studies. These social interactions are now being increasingly shaped by computer mediated communication (CMC). Two recent trends make investigation of the effects of CMC on social interactions relevant. First, Generation Y, which grew up with the Internet, will dominate the demographics of the organizations in the future. Second, the rise of social networking tools in the organizations. To investigate these issues, one conceptual and two empirical studies were conducted. Study 1 conceptualizes the impact of CMC on social interactions. Its central argument is: social capital is built on the foundation of social interactions; its development and maintenance relies on communications that are increasingly supported by CMC. Study 2 is empirical. This study attempts to address the past disparate results about the effects of the Internet on the number of social ties by incorporating various types of Internet usage instead of traditional net use measure. The results indicate entertainment use of the Internet results in isolation irrespective of context investigated in this Study. Higher entertainment use led to less ties and low centrality. In contrast, socializing use of Internet led to more ties and high centrality in close friendship neworks. Finally, learning use of Internet led to more ties and centrality in advice networks. Study 3 is an emperical study in an organization setting which investigates the importance of CMC-based and face to face ties in the context of knowledge sharing. The results indicate that CMC based ties are more diverse than face to face ties and are more associated with competence based trust. The CMC based strong ties are most significantly associated with knowedge sharing because CMC-based strong ties possess the required trust as well as the unique information to share with the focal individual. Once CMC ties are taken into account, the addition of face to face ties adds little predictive ability, explaining less than 1% variance over and above what is already explained by CMC based ties. Key words. Computer Mediated Communications, Knowledge Sharing, Social Networking Sites, Social Networks, Social Interactions, Social Capital The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Mobile network adaptation in the UbiData mobile file system
Authors: J. A. Zhang, S. F. Jones, A. S. Helal
Venue: International Journal of Computers and Applications (2008)

An important characteristic of mobile networks is the large variations of available bandwidth. Network conditions can vary from strong to weak to total disconnection. These variations may be masked from the users by a common technique called "data hoarding". Limited mobile network bandwidth is an expensive resource today and in the foreseeable future. Efficiently utilizing scarce mobile bandwidth is a challenge for managing data in the mobile environment. In this paper, we introduced the network adaptation approaches used in the UbiData mobile file system. UbiData mobile file system is designed to automatically select a mobile user's active data set and automatically migrate that data when the user switches from device to device. Automation of data management, including data set selection, data replication, network adaptation, and data reintegration, is a goal in our system to tackle the problems incurred from data unavailability in weak and disconnection modes. We discuss the adaptation techniques in our UbiData system and present enhancements. To further reduce the network bandwidth requirement, two major approaches are introduced in our system. First, the communication requests are shortly delayed and optimized. Secondly, we employ content aware/transparent adaptation to reduce possible data transmission within acceptable weak connection bandwidth. The mobile network adaptation techniques can significantly reduce the potential communications between the mobile devices and the fixed host.
A mixed integer linear program and tabu search approach for the complementary edge covering problem
Authors: Ali Naimi Sadigh, Marzieh Mozafari, Ali Husseinzadeh Kashan
Venue: Advances in Engineering Software (2010)

In this paper we study a complementary edge covering problem (CECP) as a variant of the total edge covering problem (TECP) which has application in the area of facility location. Unlike TECP, the partial cover of an edge through vertices is allowed in CECP such that in a feasible solution the entire edge will be covered. We propose a new mixed integer linear formulation for the problem. A number of size reduction rules are proposed which speed up getting optimal solution(s). Since the CECP is NP-Hard, a solution method based on tabu search is designed to search for optimal or near-optimal solutions. Computational experiments are carried out to evaluate effectiveness of the proposed mathematical formulation and the modified tabu search algorithm. Results justify that the proposed mathematical model can solves problems with up to 40 vertices and 456 edges optimally. Our computational efforts signify that the proposed tabu search is very effective and can find high quality solutions for larger problems in reasonable amount of time.
Short Communication: Churn models for prepaid customers in the cellular telecommunication industry using large data marts
Authors: Marcin Owczarczuk
Venue: Expert Systems with Applications: An International Journal (2010)

In this article, we test the usefulness of the popular data mining models to predict churn of the clients of the Polish cellular telecommunication company. When comparing to previous studies on this topic, our research is novel in the following areas: (1) we deal with prepaid clients (previous studies dealt with postpaid clients) who are far more likely to churn, are less stable and much less is known about them (no application, demographical or personal data), (2) we have 1381 potential variables derived from the clients' usage (previous studies dealt with data with at least tens of variables) and (3) we test the stability of models across time for all the percentiles of the lift curve - our test sample is collected six months after the estimation of the model. The main finding from our research is that linear models, especially logistic regression, are a very good choice when modelling churn of the prepaid clients. Decision trees are unstable in high percentiles of the lift curve, and we do not recommend their usage.
CandiSNPer
Authors: Armin O. Schmitt, Jens Aßmus, Ralf H. Bortfeldt, Gudrun A. Brockmann
Venue: Bioinformatics (2010)

Summary: Human single nucleotide polymorphism (SNP) chips which are used in genome-wide association studies (GWAS) permit the genotyping of up to 4 million SNPs simultaneously. To date, about 1000 human SNPs have been identified as statistically significantly associated with a disease or another trait of interest. The identified SNP is not necessarily the causal variant, but it is rather in linkage disequilibrium (LD) with it. CandiSNPer is a software tool that determines the LD region around a significant SNP from a GWAS. It provides a list with functional annotation and LD values for the SNPs found in the LD region. This list contains not only the SNPs for which genotyping data are available, but all SNPs with rs-IDs, thus increasing the likelihood to include the causal variant. Furthermore, plots showing the LD values are generated. CandiSNPer facilitates the preselection of candidate SNPs for causal variants. Availability and Implementation: The CandiSNPer server is freely available at http://www2.hu-berlin.de/wikizbnutztier/software/CandiSNPer. The source code is available to academic users ‘as is’ upon request. The web site is implemented in Perl and R and runs on an Apache server. The Ensembl database is queried for SNP data via Perl APIs. Contact: armin.schmitt@agrar.hu-berlin.de The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
A fuzzy ensemble of parallel polynomial neural networks with information granules formed by fuzzy clustering
Authors: Seok-Beom Roh, Sung-Kwun Oh, Witold Pedrycz
Venue: Knowledge-Based Systems (2010)

In this paper, we introduce a new category of fuzzy models called a fuzzy ensemble of parallel polynomial neural network (FEP^2N^2), which consist of a series of polynomial neural networks weighted by activation levels of information granules formed with the use of fuzzy clustering. The two underlying design mechanisms of the proposed networks rely on information granules resulting from the use of fuzzy C-means clustering (FCM) and take advantage of polynomial neural networks (PNNs). The resulting model comes in the form of parallel polynomial neural networks. In the design procedure, in order to estimate the optimal values of the coefficients of polynomial neural networks we use a weighted least square estimation algorithm. We incorporate various types of structures as the consequent part of the fuzzy model when using the learning algorithm. Among the diverse structures being available, we consider polynomial neural networks, which exhibit highly nonlinear characteristics when being viewed as local learning models. We use FCM to form information granules and to overcome the high dimensionality problem. We adopt PNNs to find the optimal local models, which can describe the relationship between the input variables and output variable within some local region of the input space. We show that the generalization capabilities as well as the approximation abilities of the proposed model are improved as a result of using polynomial neural networks. The performance of the network is quantified through experimentation in which we use a number of benchmarks already exploited within the realm of fuzzy or neurofuzzy modeling.
Fault tolerance routing for wavelength routed optical networks in ONoC
Authors: L. Zhang, Y. Jiang, E. E. Regentova
Venue: International Journal of Computers and Applications (2008)

As a promising replacement for the conventional wire-connected on-chip micro-networks, the wavelength routed optical network (WRON) is an optical interconnection architecture particularly suitable for future super large system-on-chips. In this paper, we will lay down the theoretical foundations concerning the enumeration of all the routing paths that exist in a WRON. Actually, all the links and the nodes that a routing path has to pass through can now be enumerated under this proposed theoretical framework. Availability of such detailed information of a routing path at the node/link level makes it possible to analyse the WRON network behaviour when a fault exists. Specially, four types of faults are modelled in the WRON, and subsequently, we propose a set of procedures to locate the fault if it exists. Because the data transmission in an optical network is at the speed of light, the delay due to the non-shortest path data transmission tends to be negligibly small. This observation leads us to propose a multiplepass-transmission (MT) scheme which can be applied to rebuild the data transmission paths by bypassing/avoiding the detected fault location.
A temporal data mining approach for shelf-space allocation with consideration of product price
Authors: Maryam Nafari, Jamal Shahrabi
Venue: Expert Systems with Applications: An International Journal (2010)

Marketing research has suggested that the in-store stimuli such as shelf-space allocation and product assortment have great influence on customer buying behaviour and may induce sales by maximizing impulse buying and cross-selling. The previous studies, however, have ignored the effect of product price in shelf-space arrangement. That is, they study the relationship between products and their simultaneous sales in a static fashion, disregarding the dynamic changes of their prices. The changes in product price may change the association between products such as complementarity and substitutability relationships. Consequently, it would affect the applied strategies of shelf allocation. In this paper a new approach is developed to optimally select and price the products and allocate them to shelf space with consideration of their prices. This paper takes advantage of data mining techniques, association rules, to find relationships between products regarding to their prices. Finally, to show the efficiency and effectiveness of the proposed approach, the experiment on real world data is executed.
Brief paper: Path following using transverse feedback linearization: Application to a maglev positioning system
Authors: Christopher Nielsen, Cameron Fulford, Manfredi Maggiore
Venue: Automatica (Journal of IFAC) (2010)

This article presents an approach to path following control design based on transverse feedback linearization. A ''transversal'' controller is designed to drive the output of the plant to the path. A ''tangential'' controller meets the application-specific requirements on the path, such as speed regulation and internal stability. This methodology is applied to a five-degree-of-freedom (5-DOF) magnetically levitated positioning system. Experimental results are provided that demonstrate the effectiveness of our control design.
Metscape
Authors: Jing Gao, V. Glenn Tarcea, Alla Karnovsky, Barbara R. Mirel, Terry E. Weymouth, Christopher W. Beecher, James D. Cavalcoli, Brian D. Athey, Gilbert S. Omenn, Charles F. Burant, H. V. Jagadish
Venue: Bioinformatics (2010)

Summary: Metscape is a plug-in for Cytoscape, used to visualize and interpret metabolomic data in the context of human metabolic networks. We have developed a metabolite database by extracting and integrating information from several public sources. By querying this database, Metscape allows users to trace the connections between metabolites and genes, visualize compound networks and display compound structures as well as information for reactions, enzymes, genes and pathways. Applying the pathway filter, users can create subnetworks that consist of compounds and reactions from a given pathway. Metscape allows users to upload experimental data, and visualize and explore compound networks over time, or experimental conditions. Color and size of the nodes are used to visualize these dynamic changes. Metscape can display the entire metabolic network or any of the pathway-specific networks that exist in the database. Availability: Metscape can be installed from within Cytoscape 2.6.x under ‘Network and Attribute I/O’ category. For more information, please visit http://metscape.ncibi.org/tryplugin.html Contact: jinggao@umich.edu Supplementary information:Supplementary data are available at Bioinformatics online. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
The human analysis element of intrusion detection: a cognitive task model and interface design and implications
Authors: Maxine S. Cohen
Venue:  (2009)

The use of monitoring and intrusion detection tools are common in today&rsquo;s network security architecture. The combination of tools generates an abundance of data which can result in cognitive overload of those analyzing the data. ID analysts initially review alerts generated by intrusion detection systems to determine the validity of the alerts. Since a large number of alerts are false positives, analyzing the data can severely reduce the number of unnecessary and unproductive investigations. The problem remains that this process is resource intensive. To date, very little research has been done to clearly determine and document the process of intrusion detection. In order to rectify this problem, research was conducted which involved several phases. Fifteen individuals were selected to participate in a cognitive task analysis. The results of the cognitive task analysis were used to develop a prototype interface which was tested by the participants. A test of the participants&rsquo; knowledge after the use of the prototype revealed an increase in both effectiveness and efficiency in analyzing alerts. Specifically, the findings revealed an increase in effectiveness as 72% of the participants made better determinations using the prototype interface. The results also showed an increase in efficiency when 72% of the participants analyzed and validated alerts in less time while using the prototype interface. These findings, based on empirical data, showed that the use of the task diagram and prototype interface helped to reduce the amount of time it previously took to analyze alerts generated by intrusion detection systems. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Role of spiral wave pinning in inhomogeneous active media in the termination of atrial fibrillation by electrical cardioversion
Authors: Pawel Kuklik, Christopher X. Wong, Anthony G. Brooks, Jan Jacek Żebrowski, Prashanthan Sanders
Venue: Computers in Biology and Medicine (2010)

Atrial fibrillation is the most common type of arrhythmia to affect humans. One of the treatment modalities for atrial fibrillation is an electrical cardioversion. Electrical cardioversion can result in one of three outcomes: an immediate termination of arrhythmic activity, a delayed termination or unsuccessful termination. The mechanism of delayed termination is unknown. Here we present a model of an atrial fibrillation as a coexistence of several spiral waves pinned to the inhomogeneities in active media. We show that in inhomogeneous system delayed termination can be explained as the unpinning of a spiral wave from inhomogeneities and its termination after collision with the edge of the system.
A rough set approach for selecting clustering attribute
Authors: Tutut Herawan, Mustafa Mat Deris, Jemal H. Abawajy
Venue: Knowledge-Based Systems (2010)

A few of clustering techniques for categorical data exist to group objects having similar characteristics. Some are able to handle uncertainty in the clustering process while others have stability issues. However, the performance of these techniques is an issue due to low accuracy and high computational complexity. This paper proposes a new technique called maximum dependency attributes (MDA) for selecting clustering attribute. The proposed approach is based on rough set theory by taking into account the dependency of attributes of the database. We analyze and compare the performance of MDA technique with the bi-clustering, total roughness (TR) and min-min roughness (MMR) techniques based on four test cases. The results establish the better performance of the proposed approach.
Solving PDEs in non-rectangular 3D regions using a collocation finite element method
Authors: Granville Sewell
Venue: Advances in Engineering Software (2010)

The general-purpose partial differential equation (PDE) solver PDE2D uses a Galerkin finite element method, with standard triangular elements of up to fourth degree, to solve PDEs in general 2D regions. For 3D problems, a very different approach is used, which involves a collocation finite element method, with tricubic Hermite basis functions, and an automatic global coordinate transformation. If the user can define the 3D region by X=X(P1,P2,P3),Y=Y(P1,P2,P3),Z=Z(P1,P2,P3) with constant limits on P1,P2,P3, then the PDEs and boundary conditions can be written in their usual Cartesian coordinate form and PDE2D will automatically convert the equations to the new coordinate system and solve the problem internally in this rectangle. The result is that for a wide range of simple 3D regions, once the global coordinate system is defined, the rest of the input is as simple as if the region were a rectangle.
Reduction of power system model using balanced realization, routh and pade approximation methods
Authors: N. Singh, R. Prasad, H. O. Gupta
Venue: International Journal of Modelling and Simulation (2008)

A time domain model reduction technique based on balanced realization has been applied to a single machine power system model i.e., a synchronous machine connected to an infinite bus through transmission line. The controllability and observability grammians have been computed by solving the Lyapunov equations. The high order system is transformed into balanced form by using the similarity transformation matrix to bring the grammian matrices to the balanced format, which is used to formulate the reduced order model in state space form. The results have also been compared with the Routh and Pade approximation methods, the two well-known frequency domain techniques. The comparison of time and frequency responses shows that, the reduced order models satisfactorily approximate the original system.