ppxscal/embedding_network huggingface dataset:
Serengeti broadband
Authors: Amos M. Nungu, Bjorn Pehrson, Nsubis Genesis
Venue: Proceedings of the second ACM SIGCOMM workshop on Networked systems for developing regions (2008)

This paper presents a broadband island defined by a fibre-optic communication network between Bunda and Serengeti, two rural districts in the Mara region in northern Tanzania. The purpose of the network is to facilitate creation and sharing of information at government institutions. The network is also expected to create jobs and entrepreneurial activities in these under-served areas The network is comprised of an optical fibre backbone and wireless local area networks operating in license-free spectrum as access networks. The fibre is currently terminated at three locations. VLAN-capable Ethernet switches with long range optical transceivers provide backbone transmission as well as fibre access. To minimize costs, routers and servers in the network are all based on standard PC hardware and Free Open Source software. The infrastructure is operated under an Open Access regime, other ways of resource sharing like virtualization at the link; network and application layers are explored. Although the broadband island defined by the fibre has a narrowband VSAT connection to the Internet, the focus on the services provided in the network is local, focusing on e-government, education, healthcare and support to local entrepreneurs.
Using FORAY models to enable MPSoC memory optimizations
Authors: Ilya Issenin, Nikil Dutt
Venue: International Journal of Parallel Programming (2008)

With the technology advances it becomes feasible to implement a large multiprocessor system on a single chip. In such Systems-on-Chip (SoCs), a significant portion of energy is spent in the memory subsystem. There are several approaches reducing this energy, including the ones at physical, architecture and algorithmic levels. Classical approaches, including algorithmic and some architectural approaches, use static analysis and transformation of the application source code. However, often it is not possible to perform static analysis and optimization of a program's memory access behavior unless the program is written in an easily analyzable form, e.g., free from pointer arithmetic. In this paper, we introduce the FORAY model of a program that allows aggressive analysis of the application's memory behavior and enables such optimizations on arbitrary code which are not possible to apply otherwise. We then present FORAY-GEN: an automated profile-based approach for extraction of the FORAY model from the original program. We also outline our approach in applying FORAY-GEN for multiprocessor SoCs. We demonstrate how FORAY-GEN enhances applicability of other memory subsystem optimization approaches, resulting in an average of two times increase in the number of memory references that can be analyzed by existing static approaches.
Effect of feature-type in selecting distance measure for an artificial immune system as a pattern recognizer
Authors: Seral Özşen, Salih Güneş
Venue: Digital Signal Processing (2008)

In designing an artificial immune system (AIS) for a problem domain, one must select a distance measure to find the affinity between system units and input data after determining a representation type. Euclidean distance is a commonly used distance measure in many proposed methods and is selected intuitively or due to simplicity of implementation. But this selection must be done carefully by considering the properties of problem domain. For example, most problems use data vectors with discrete, real-valued and nominal feature values. Whereas Euclidean distance can be used in this kind of problems, some other similarity measures designed for these hybrid vectors would give better results. To call attention of AIS designer to this point, we have tested three distance criteria which are Euclidean distance, Manhattan distance, and hybrid similarity measure on a simple AIS for the classification of two medical dataset taken from the UCI machine learning repository. One of the datasets, Statlog heart disease, contains nominal, discrete and real-valued vectors while the other one, BUPA liver disorders dataset, consists of purely real-valued vectors. For Statlog dataset, the best classification result was obtained with hybrid similarity measure as expected because this dataset consists of three-types of features while results for BUPA dataset were not different so much for the used measures, which is also an expected result considering the nature of this dataset.
The minimum spanning tree problem with fuzzy costs
Authors: Adam Janiak, Adam Kasperski
Venue: Fuzzy Optimization and Decision Making (2008)

In this paper the minimum spanning tree problem in a given connected graph is considered. It is assumed that the edge costs are not precisely known and they are specified as fuzzy intervals. Possibility theory is applied to characterize the optimality of edges of the graph and to choose a spanning tree under fuzzy costs.
Electronically Tunable Frequency Filters Based on Transformation Cells
Authors: Jaroslav Koton, Kamil Vrba
Venue: Proceedings of the Third International Conference on Systems (2008)

In the paper a novel circuit structure realizing a grounded parallel nth-order synthetic immittance system is introduced. Voltage conveyors (VCs) and transadmittance amplifiers (OTAs) are used as active elements. The use of the current-controlled OTAs enables modifying simply the parameters of the synthetic element designed. A further advantage of the synthetic element presented is that all the passive elements used are grounded. The application of the controlled synthetic elements is shown on a realization of tunable 4th-order frequency filters, where the cut-off frequency can be changed in a range from 1 kHz to 1 MHz. The symbolic-analysis conclusions are supplemented by PSpice simulation results.
Benchmarking Domain-Specific Compiler Optimizations for Variational Forms
Authors: Robert C. Kirby, Anders Logg
Venue: ACM Transactions on Mathematical Software (TOMS) (2008)

We examine the effect of using complexity-reducing relations [Kirby et al. 2006] to generate optimized code for the evaluation of finite-element variational forms. The optimizations are implemented in a prototype code named FErari, which has been integrated as an optimizing backend to the FEniCS form compiler, FFC [Kirby and Logg 2006; 2007]. In some cases, FErari provides very little speedup, while in other cases we obtain reduced local operation counts by a factor of as much as 7.9 and speedups for the assembly of the global sparse matrix by as much as a factor of 2.8 (see Figure 9).
A Chernoff bound for random walks on expander graphs
Authors: D. Gillman
Venue: Proceedings of the 1993 IEEE 34th Annual Foundations of Computer Science (1993)

We consider a finite random walk on a weighted graph G; we show that the sample average of visits to a set of vertices A converges to the stationary probability /spl pi/(A) with error probability exponentially small in the length of the random walk and the square of the size of the deviation from /spl pi/(A). The exponential bound is in terms of the expansion of G and improves previous results. We show that the method of taking the sample average from one trajectory is a more efficient estimate of /spl pi/(A) than the standard method of generating independent sample points from several trajectories. Using this more efficient sampling method, we improve the algorithms of Jerrum and Sinclair (1989) for approximating the number of perfect matchings in a dense graph and for approximating the partition function of an Ising system. We also give a fast estimate of the entropy of a random walk on an unweighted graph.
Performance Analysis of Dynamic Group Communication Systems with Intrusion Detection Integrated with Batch Rekeying in Mobile Ad Hoc Networks
Authors: Jin-Hee Cho, Ing-Ray Chen, Phu-Gui Feng
Venue: Proceedings of the 22nd International Conference on Advanced Information Networking and Applications - Workshops (2008)

We investigate performance characteristics of secure group communication systems (GCSs) in mobile ad hoc networks that employ intrusion detection techniques for dealing with insider attacks tightly coupled with rekeying techniques for dealing with outsider attacks. The objective is to identify optimal settings including the best intrusion detection interval and the best batch rekey interval under which the system lifetime (mean time to security failure) is maximized while satisfying performance requirements. We develop a mathematical model based on stochastic Petri net (SPN) to analyze tradeoffs between security and performance properties, when given a set of parameter values characterizing operational and environmental conditions of a GCS instrumented with intrusion detection tightly coupled with batch rekeying. We compare our design with a baseline system using intrusion detection integrated with individual rekeying to demonstrate the effectiveness.
Mean-square performance of the family of adaptive filters with selective partial updates
Authors: Mohammad Shams Esfand Abadi, John Håkon Husøy
Venue: Signal Processing (2008)

In this paper we present a general formalism for the family of adaptive filter algorithms with selective partial updates. Based on this, the mean-square performance analysis of this family of adaptive filters is presented in a unified way. This analysis is based on energy conservation arguments and does not need to assume a Gaussian or white distribution for the regressors. We demonstrate through simulations that the results are useful in predicting the performance of this family of adaptive filters.
Cognitive partnerships on the bench top: designing to support scientific researchers
Authors: Ellie Harmon, Nancy J. Nersessian
Venue: Proceedings of the 7th ACM conference on Designing interactive systems (2008)

There has been a growing interest to develop technologies for laboratory environments. However, existing systems are underdeployed in real research labs. In order to create more successful technologies for the creative laboratory setting, we need a deeper understanding of the values of the researchers we are designing for and the unique roles of technology in the research laboratory. Our three-year ethnographic study of a biomedical engineering (BME) lab contributes to building this foundation for future design. Drawing form a distributed and situated cognition framework, our analysis highlights the ways in which technology is integrated into the researchers' daily practices. This study is one of the first deep ethnographies of a laboratory culture with a central focus on technology and provides several insights for the design community.
The accuracy of statistical distributions in Microsoft®Excel 2007
Authors: A. Talha Yalta
Venue: Computational Statistics Data Analysis (2008)

We provide an assessment of the statistical distributions in Microsoft^(R) Excel versions 97 through 2007 along with two competing spreadsheet programs, namely Gnumeric 1.7.11 and OpenOffice.org Calc 2.3.0. We find that the accuracy of various statistical functions in Excel 2007 range from unacceptably bad to acceptable but significantly inferior in comparison to alternative implementations. In particular, for the binomial, Poisson, inverse standard normal, inverse beta, inverse student's t, and inverse F distributions, it is possible to obtain results with zero accurate digits as shown with numerical examples.
Convex comparisons for random sums in random environments and applications
Authors: José maría Fernández-ponce, Eva maría Ortega, Franco Pellerey
Venue: Probability in the Engineering and Informational Sciences (2008)

Recently, Belzunce, Ortega, Pellerey, and Ruiz [3] have obtained stochastic comparisons in increasing componentwise convex order sense for vectors of random sums when the summands and number of summands depend on a common random environment, which prove how the dependence among the random environmental parameters influences the variability of vectors of random sums. The main results presented here generalize the results in Belzunce et al. [3] by considering vectors of parameters instead of a couple of parameters and the increasing directionally convex order. Results on stochastic directional convexity of families of random sums under appropriate conditions on the families of summands and number of summands are obtained, which lead to the convex comparisons between random sums mentioned earlier. Different applications in actuarial science, reliability, and population growth are also provided to illustrate the main results.
Fast communication: Autocorrelation-invariant discrete-time functions and associated orthogonal sequences
Authors: P. Bréhonnet, N. Tanguy, P. Vilbé, L. -C. Calvez
Venue: Signal Processing (2008)

The paper studies frequency domain characterization and properties of autocorrelation discrete-time functions. Such functions may be useful in the design and synthesis of signaling waveforms with prescribed autocorrelation functions.
Virtually True: Questioning Online Media, First edition
Authors: Guofang Wan
Venue:  (2007)

Encourages readers to question the influential messages of online media. Describes what media is and how the Internet is a part of media.
A Production Support Infrastructure for Live Student Projects
Authors: Jeff Pittges
Venue: Proceedings of the Fifth International Conference on Information Technology: New Generations (2008)

The benefits to students who work on live projects are well documented, but the challenges of supporting the students, the clients, and the deliverables are largely unaddressed. Radford University has created the Small Project Support Center (SPSC) to coordinate live student projects and to support the applications that are deployed into production. This paper describes an infrastructure of tools, people, and processes developed by the SPSC to support live student projects from the initial project evaluation through development, deployment, and operation in a production environment.
A multi-agent-based model for a negotiation support system in electronic commerce
Authors: H. Li, H. Wang
Venue: Enterprise Information Systems (2007)

This study proposes a multi-agent-based model for bilateral multi-objective negotiation in electronic commerce trading. The function and behaviour of several types of agents are discussed. These agents interact with each other in our negotiation support system model to create the most appropriate solution for both negotiating parties. In particular, we are concerned with a win-win negotiation approach in which agents seek to strike a fair deal that also maximizes the payoff for everyone involved. That is, if the opponent cannot accept an offer then the proponent should endeavour to find an alternative to make a trade-off. Against this background, a utility model based on fuzzy constraint satisfaction problems is proposed to ensure that these agents reach a solution that is fair for both negotiating parties if such a solution exists. The model uses prioritized fuzzy constraints to indicate how concessions should be made when necessary. In addition, by incorporating the notion of a negotiation argument into our evaluation model, the agents can sometimes reach agreements that would otherwise be impossible. Finally, a numerical example is given to display the applicability of the proposed approach for electronic trading assistance.
Three Dimensional Face Recognition Using SVM Classifier
Authors: Mir Hashem Mousavi, Karim Faez, Amin Asghari
Venue: Proceedings of the Seventh IEEE/ACIS International Conference on Computer and Information Science (icis 2008) (2008)

In this paper, we presented a novel approach for automated 3D face recognition using range data. An object recognition system generally consists of two main parts: data registration and data comparison. In first step, the nose tip was used as the reference point and 3D face shape was normalized to standard image size. The 2DPCA was applied to the resultant range data and the corresponding principal images were used as the feature vectors. Classification was carried out by calculating the similarity score between the feature vectors. The SVM classifier was used in choosing the closest match. Recognition rate of 97% rank-four was achieved
Frequency-based representation of 3D point-based surfaces using spherical harmonics
Authors: M. Mousa, R. Chaine, S. Akkouche
Venue: Machine Graphics Vision International Journal (2006)

In this paper, we propose a precise frequency-based representation for oriented point-based surfaces using spherical harmonics. The representation can be useful in many applications, such as filtering, progressive transmission and coding of 3D surfaces. The basic computation in our approach is the spherical harmonics transform of local spherical radial functions induced by a set of points. An important feature of our approach is that the calculations are performed directly on local 2D triangulations of the point-based surface without any prior space voxelization. This property ensures that the complexity of our computation of the spherical harmonics transform is linear in the number of triangles in the local patch. We present some experimental results which demonstrate our technique.
On the polytope of non-additive measures
Authors: Elías F. Combarro, Pedro Miranda
Venue: Fuzzy Sets and Systems (2008)

In this paper we deal with the problem of studying the structure of the polytope of non-additive measures for finite referential sets. We give a necessary and sufficient condition for two extreme points of this polytope to be adjacent. We also show that it is possible to find out in polynomial time whether two vertices are adjacent. These results can be extended to the polytope given by the convex hull of monotone Boolean functions. We also give some results about the facets and edges of the polytope of non-additive measures; we prove that the diameter of the polytope is 3 for referentials of three elements or more. Finally, we show that the polytope is combinatorial and study the corresponding properties; more concretely, we show that the graph of non-additive measures is Hamilton connected if the cardinality of the referential set is not 2.
Sharing usability information in interactive system development
Authors: Paula M. Bach, Jiang Hao, John M. Carroll
Venue: Proceedings of the 2008 international workshop on Cooperative and human aspects of software engineering (2008)

In this paper we report on a preliminary study of usability information sharing in interactive system development. The study was conducted at a large technology company in the United States. The purpose of the study was to understand the usability information sharing practices of various members of multidisciplinary interactive system development teams. We found that the different job roles, specifically, usability expert, developer, and project manager share usability information in many ways.
Feature selection to diagnose a business crisis by using a real GA-based support vector machine: An empirical study
Authors: Liang-Hsuan Chen, Huey-Der Hsiao
Venue: Expert Systems with Applications: An International Journal (2008)

This research is aimed at establishing the diagnosis models for business crises through integrating a real-valued genetic algorithm to determine the optimum parameters and SVM to perform learning and classification on data. After finishing the training processes, the proposed GA-SVM can reach a prediction accuracy of up to 95.56% for all the tested business data. Particularly, only six influential features are included in the proposed model with intellectual capital and financial features after the 2-phase selecting process; the six features are ordinary and widely available from public business reports. The proposed GA-SVM is available for business managers to conduct self-diagnosis in order to realize whether business units are really facing a crisis.
Matrix solvers for computational fluid dynamics
Authors: Sijun Zhang, Ed Blosch, Xiang Zhao
Venue: Proceedings of the 10th WSEAS International Conference on APPLIED MATHEMATICS (2006)

The SIMPLE family sequential methods have been successfully applied for many fluid dynamics problems involving such as low/high speed flows, combustion, and multi-phase flows. The convergence of the pressure correction equation is directly related to the conservation of mass and is of crucial importance to guarantee the overall convergence. However, the matrixes of the discretized pressure correction equations are nonsymmetric and not (or weakly) diagonally dominant generally. Many iterative methods are not efficient and even fail to converge when they are applied to such equations. Due to the important role and the different matrix property, the most of computing time is spent on the solution of the pressure correction equation. The CGS, Bi-CGSTAB and GMRES(m) matrix solvers are incorporated to solve the pressure correction equation in an unstructured grid Navier-Stokes flow solver in this study. The robustness of different matrix solver has been tested on a variety of cases. The efficiency of the methods is measured in terms of the computing time required to obtain a steady state solution for a solid rocket motor flow. Numerical computation is also conducted for a time accurate solution of combustion in a ramjet combustor. It turns out that the restarting version of GMRES(m) is efficient and robust for solving the linear system of pressure correction equation with the extra cost of computer memory requirements.
Some notes on multivariate generalized Pareto distributions
Authors: René Michel
Venue: Journal of Multivariate Analysis (2008)

The investigation of multivariate generalized Pareto distributions (GPDs) has begun only recently and there are slightly varying definitions of GPDs available. In this article we investigate the one from Section 5.1 of Falk et al. [Laws of Small Numbers: Extremes and Rare Events, second ed., Birkhauser, Basel, 2004], which does not differ in the area of interest from those of other authors. We first give an interpretation of the case of independence in terms of the peaks-over-threshold approach. This case is also used in dimension d=3 by Falk et al. [Laws of Small Numbers: Extremes and Rare Events, second ed., Birkhauser, Basel, 2004] as a counterexample to show that GP functions are not necessarily distribution functions on their entire support. We generalize this counterexample to an arbitrary dimension d>=3 and demonstrate also that other GP functions show this behavior. Finally we show that different GPDs can lead to the same conditional probability measure in the area of interest.
Modeling of interaction design by end users through discourse modeling
Authors: Cristian Bogdan, Hermann Kaindl, Jürgen Falb, Roman Popp
Venue: Proceedings of the 13th international conference on Intelligent user interfaces (2008)

End users of software typically have to let someone else develop it and its user interface, or to learn to design and to program it themselves. Especially user interfaces developed by someone else may not fit well the given task. Designing and programming is hard and takes a lot of effort in general, and even more so for people not especially trained or experienced. Therefore, we propose end-user development of user interfaces through a new approach and interface for discourse modeling. End users may themselves model an interaction design as a discourse (in the sense of a dialogue between human and computer). From such an interaction design, eventually a user interface is to be generated automatically by a tool. As a consequence, end-user development becomes end-user modeling instead of programming.