ppxscal/embedding_network huggingface dataset:
UMTS-HSDPA in High Altitude Platforms (HAPs) communications with finite transmitted power and unequal cell's load
Authors: Bazil Taha-Ahmed, Miguel Calvo-Ramón
Venue: Computer Communications (2009)

In this paper, the performance of HAPs (High Altitude Platforms) UMTS HSDPA (High Speed Downlink Packet Access) is studied for different scenarios and two directions (0^o and 30^o) within the cell where the network under study is assumed to have 61 cells. It is concluded that, for urban zone users, the effective range is lower than the effective range for users in rural zones. It is shown that in rural zones, the HSDPA mode can support the modulation 16QAM with 7/8 code rate when cells are not fully loaded. For fully loaded rural cells, the 16QAM modulation scheme with code rate of 7/8 cannot be supported. Also, it is noticed that, in urban zones, HSDPA mode can support 16QAM with code rate of 1/2 and QPSK modulation schemes when cells are not fully loaded. For fully loaded urban cells, only QPSK with code rate of 1/2 can be supported.
Enumerating Membrane Structures
Authors: Vincenzo Manca
Venue: Membrane Computing: 9th International Workshop, WMC 2008, Edinburgh, UK, July 28-31, 2008, Revised Selected and Invited Papers (2009)

A recurrent formula for enumerating membrane structures is given. It is deduced by elementary combinatorial methods, by providing a simplification with respect to a classical formula for the enumeration of trees, which is based on the analytical method of generating functions.
Development of fuzzy and control charts using α-cuts
Authors: Sevil Senturk, Nihal Erginel
Venue: Information Sciences: an International Journal (2009)

Statistical process control (SPC) is an approach that uses statistical techniques to monitor the process. Shewhart introduced the control charts that are one of the most important techniques of quality control to detect if assignable causes exist. The widely used control charts are and . These are called traditional variable control charts. In the traditional variable control charts, center line, upper control limit and lower control limit are represented by numeric values. A process is either "in control" or "out of control" depending on numeric observation values. For many problems, control limits could not be so precise. Uncertainty comes from the measurement system including operators and gauges, and environmental conditions. In this context, fuzzy set theory is a useful tool to handle this uncertainty. Numeric control limits can be transformed to fuzzy control limits by using membership functions. If a sample mean is too close to the control limits and the used measurement system is not so sensitive, the decision may be faulty. Fuzzy control limits provide a more accurate and flexible evaluation. This study constructs the fuzzy and control charts with @a-cuts. An application is presented for fuzzy control charts. By using fuzzy and control charts, the flexibility of traditional control limits is increased.
Distinguishing humans from robots in web search logs: preliminary results using query rates and intervals
Authors: Omer Duskin, Dror G. Feitelson
Venue: Proceedings of the 2009 workshop on Web Search Click Data (2009)

The workload on web search engines is actually multiclass, being derived from the activities of both human users and automated robots. It is important to distinguish between these two classes in order to reliably characterize human web search behavior, and to study the effect of robot activity. We suggest an approach based on a multi-dimensional characterization of search sessions, and take first steps towards implementing it by studying the interaction between the query submittal rate and the minimal interval of time between different queries.
ROISeer: Region-Based Image Retrieval by Hierarchical Feature Filtering
Authors: Zou Lei, Bizhong Wei, Xiaodong Cai, Yuelin Chen
Venue: Proceedings of the 9th Pacific Rim Conference on Multimedia: Advances in Multimedia Information Processing (2008)

In this paper, an image retrieval system, ROISeer is proposed. ROISeer uses a region-based approach for feature extraction, and integrated region matching based upon color and shape similarity measurements. Different from most existing image query by example systems, the proposed system provides a hierarchical feature filtering instead of using single or multiple features fusion. It considers that color feature is the most significant factor simulating the attention of Human Visual System (HVS), therefore image segmentation procedure is only applied for those image where similar color patch is presented. The novel design of this technique significantly reduces the complexity of image segmentation for large scale image databases. In addition, to enhance the reliability of the system, a region-based shape matching algorithm is utilized. This method ensures that the same region is robustly retrieved when the target is rotated, resized and shifted. Experimental results show that the ROISeer provides robust and well performance in Region of Interest (ROI) retrieval in single category or cross-category image databases.
Adapting Application Mapping to Systematic Within-Die Process Variations on Chip Multiprocessors
Authors: Yang Ding, Mahmut Kandemir, Mary Jane Irwin, Padma Raghavan
Venue: Proceedings of the 4th International Conference on High Performance Embedded Architectures and Compilers (2008)

Process variations, which lead to timing and power variations across identically-designed components, have been identified as one of the key future design challenges by the semiconductor industry. Using worst case latency/power assumptions is one option to address process variations. This option, while simplifying the problem, is becoming less and less attractive as its performance and power costs keep increasing. As a result, exploring options that allow the software to have knowledge about the actual latency/power consumption values is critical for future systems. Targeting systematic process variations, this paper makes two contributions. First, we discuss how we can assign threads to the cores of a chip multiprocessor (CMP) with process variations in mind and show the energy-delay product (EDP) benefits such a process variation-aware thread mapping can bring. Second, we study the benefits of varying the frequencies on a subset of the cores to increase EDP savings. We propose and evaluate integer linear programming based thread mapping schemes in both studies. While these schemes operate with profile data, they can be made to work with partial profiling as well with the help of curve fitting. We tested our schemes using both sequential and multi-threaded benchmarks from different suites and the results collected indicate that we can achieve EDP savings as much as 73.4%, with an average saving of 37.1% over a process variation agnostic scheme.
Creating standardised data lists for traceability: a study of honey processing
Authors: Kathryn Anne-Marie Donnelly, Kine Mari Karlsen, Petter Olsen, Joop Van Der Roest
Venue: International Journal of Metadata, Semantics and Ontologies (2008)

In food supply chains, there are numerous measurements, properties and parameters that must be recorded. This documentation is already necessary for legal reasons, labelling, traceability, profiling desirable characteristics, showing compliance and for meeting customer requirements. Standards for name and content of each of these data elements would aid information exchange between buyers, sellers, authorities, consumers and other interested parties. To establish what could form such a list of standard data elements for honey processors, a multi-stage survey was carried out. This and other research resulted in a standardised list of data elements capable of application by all honey processors.
Comparative Analysis of High Performance Solvers for 3D Elasticity Problems
Authors: Ivan Lirkov, Yavor Vutov, Maria Ganzha, Marcin Paprzycki
Venue: Numerical Analysis and Its Applications: 4th International Conference, NAA 2008, Lozenetz, Bulgaria, June 16-20, 2008. Revised Selected Papers (2009)

We consider the numerical solution of 3D linear elasticity equations. The investigated problem is described by a coupled system of second order elliptic partial differential equations. This system is then discretized by conforming or nonconforming finite elements. After applying the Finite Element Method (FEM) based discretization, a system of linear algebraic equations has to be solved. In this system the stiffness matrix is large, sparse and symmetric positive definite. In the solution process we utilize a well-known fact that the preconditioned conjugate gradient method is the best tool for efficient solution of large-scale symmetric systems with sparse positive definite matrices. In this context, the displacement decomposition (DD) technique is applied at the first step to construct a preconditioner that is based on a decoupled block diagonal part of the original matrix. Then two preconditioners, namely the Modified Incomplete Cholesky factorization MIC(0) and the Circulant Block-Factorization (CBF) preconditioning, are used to precondition thus obtained block diagonal matrix.As far as the parallel implementation of the proposed solution methods is concerned, we utilize the Message Passing Interface (MPI) communication libraries. The aim of our work is to compare the performance of the two proposed preconditioners: the DD MIC(0) and the DD CBF. The presented comparative analysis is based on the execution times of actual codes run on modern parallel computers. Performed numerical tests demonstrate the level of parallel efficiency and robustness of the proposed algorithms. Furthermore, we discuss the number of iterations resulting from utilization of both preconditioners.
Performance Evaluation of PNtMS: A Portable Network Traffic Monitoring System on Embedded Linux Platform
Authors: Mostafijur Rahman, Zahereel Ishwar Abdul Khalib, R. B. Ahmad
Venue: Proceedings of the 2009 International Conference on Computer Engineering and Technology - Volume 01 (2009)

The principal role of embedded software is the transformation of data and the interaction with the physical world stimulus. The main concern in developing embedded software for network application is the lack of published best practice software architecture for optimizing performance by means of reducing protocol processing overhead, memory usage, and power consumption. This paper presents the implementation, operation and performance evaluation of the portable network traffic monitoring system (PNtMS) on an embedded Linux platform. The system has been designed to capture network packets information from the network and performs some statistical analysis, which includes providing data on the volume and types of traffic transferred within a LAN, traffic generated per node, number of traffic going through or comming from a system or application which is causing bottleneck, and the level of peak traffic. These data are then stored into the log files, and the traffic information can be shown through web browser or onboard LCD. Result shows that PNtMS is performing at par with an existing network protocol analyzer with minimal usage of RAM ( 578 KB), low end processor (133MHz) and storage(less than 1GB).
Semantic enrichment of places: Ontology learning from web
Authors: Ana Alves, Bruno Antunes, Francisco C. Pereira, Carlos Bento
Venue: International Journal of Knowledge-based and Intelligent Engineering Systems (2009)

In this paper, we present an approach to a challenge well known from the area of Ubiquitous Computing: extracting meaning out of geo-referenced information. We believe that Public Places can also be an environment where users can be confronted with intelligent services depending on their needs. To make this a reality we need firstly an intelligent way to represent places. The importance of this "semantics of place" problem is proportional to the number of available services and data that are common nowadays. Having rich knowledge about a place, we open up a new realm of "Location Based Services" that can behave more intelligently. Our approach builds on Ontology Engineering techniques in order to build a network of semantic associations between a place and related concepts. We briefly describe the KUSCO system and present some preliminary results.
Virtual model of MAIN FRAME COMPUTER ES 1020B from Computer Museum of Mathematics and Informatics Faculty in Shumen University
Authors: Katerina Velcheva, Violeta Velcheva, Stanimir Stanev
Venue: Proceedings of the 9th International Conference on Computer Systems and Technologies and Workshop for PhD Students in Computing (2008)

The paper deals with the virtual model of the 3d generation Bulgarian mainframe computer ES1020 B, which is a part of the virtual computer museum of FMI- Shumen University. This model is important for presentation of the history of Computing in Bulgaria at the beginning of the corresponded educational courses for students in this University. The model of the computing hall and the computer is based on VRML language and gives a good imagination of the main parts of this computer. Virtual models of ES 1020 has been installed at http://info.fmi.shu-bg.net/.
Automatic analysis of 3D low dose CT images for early diagnosis of lung cancer
Authors: A. El-Baz, G. Gimel'farb, R. Falk, M. Abo El-Ghar
Venue: Pattern Recognition (2009)

Our long term research goal is to develop a fully automated, image-based diagnostic system for early diagnosis of pulmonary nodules that may lead to lung cancer. This paper focuses on monitoring the development of lung nodules detected in successive chest low dose (LD) CT scans of a patient. We propose a new methodology for 3D LDCT data registration which is non-rigid and involves two steps: (i) global target-to-prototype alignment of one scan to another using the learned prior appearance model followed by (ii) local alignment in order to correct for intricate relative deformations. After equalizing signals for two subsequent chest scans, visual appearance of these chest images is described using a Markov-Gibbs random field (MGRF) model with multiple pairwise interaction. An affine transformation that globally registers a target to a prototype is estimated by the gradient ascent-based maximization of a special Gibbs energy function. To get an accurate visual appearance model, we developed a new approach to automatic selection of most characteristic second-order cliques that describe pairwise interactions in the LDCT data. To handle local deformations, we displace each voxel of the target over evolving closed equi-spaced surfaces (iso-surfaces) to closely match the prototype. The evolution of the iso-surfaces is guided by a speed function in the directions that minimize distances between the corresponding voxel pairs on the iso-surfaces in both the data sets. Preliminary results on the 135 LDCT data sets from 27 patients show that the proposed accurate registration could lead to precise diagnosis and identification of the development of the detected pulmonary nodules.
Independent component analysis based on gradient equation and kernel density estimation
Authors: Yunfeng Xue, Yujia Wang, Jie Yang
Venue: Neurocomputing (2009)

In this paper, a new algorithm is proposed for linear instantaneous independent component analysis. This new algorithm is based on solving the gradient equation, and an iterative method is introduced to solve this equation efficiently. To make the proposed algorithm adaptive to source distributions, the density functions as well as their first and second derivatives are estimated by kernel density method. Empirical comparisons with several popular independent component analysis (ICA) algorithms confirm the efficiency and accuracy of the proposed algorithm.
Optimization of multimodal continuous functions using a new crossover for the real-coded genetic algorithms
Authors: Nedim Tutkun
Venue: Expert Systems with Applications: An International Journal (2009)

In this study, a new crossover approach to the real-coded genetic algorithm is proposed. The approach is simply based on efficiently tuned real-coded crossover operation using the probability distribution function of Gauss distribution to generate rather dissimilar strings which may be candidates of possible solutions. Also linear and quadratic mapping algorithms comparatively used both to constrain individuals in the given search spaces and to produce different individuals in order to increase average fitness relatively for the same population. Moreover, to refine genetically found optimum points the local search technique based on Newton's method was performed. The designed software was first implemented on 11 well-known test functions and their results were compared with previous findings as shown in tables. In few test functions, the elitism operator was put into effect to maintain fitness stability helping increase the search performance of the proposed algorithm. The results indicate that the solutions to the test functions were almost the same with theoretical ones and the number of function evaluations for each test function was less than that obtained from using previous approaches.
Bayesian networks: A teacher's view
Authors: Russell G. Almond, Valerie J. Shute, Jody S. Underwood, Juan-Diego Zapata-Rivera
Venue: International Journal of Approximate Reasoning (2009)

Teachers viewing Bayesian network-based proficiency estimates from a classroom full of students face a different problem from a tutor looking at one student at a time. Fortunately, individual proficiency estimates can be aggregated into classroom and other group estimates through sums and averages. This paper explores a few graphical representations for group-level inferences from a Bayesian network.
Novel lossless and lossy grounded inductor simulators consisting of a canonical number of components
Authors: Erkan Yuce
Venue: Analog Integrated Circuits and Signal Processing (2009)

In this paper, four series lossy inductor simulators including a minimum number of active and passive components, a current feedback operational amplifier (CFOA), two resistors and a capacitor, are proposed. Also, four lossless simulated inductors using a canonical number of elements, a new CFOA, two resistors and a capacitor, are developed. All the introduced circuits do not need critical component matching constraints. Simulations achieved by means of SPICE program are added so as to demonstrate the performance.
A note on approximate Nash equilibria
Authors: Constantinos Daskalakis, Aranyak Mehta, Christos Papadimitriou
Venue: Theoretical Computer Science (2009)

In view of the intractability of finding a Nash equilibrium, it is important to understand the limits of approximation in this context. A subexponential approximation scheme is known [Richard J. Lipton, Evangelos Markakis, Aranyak Mehta, Playing large games using simple strategies, in: EC, 2003], and no approximation better than 14 is possible by any algorithm that examines equilibria involving fewer than logn strategies [Ingo Althofer, On sparse approximations to randomized strategies and convex combinations, Linear Algebra and its Applications (1994) 199]. We give a simple, linear-time algorithm examining just two strategies per player and resulting in a 12-approximate Nash equilibrium in any 2-player game. For the more demanding notion of approximately well supported Nash equilibrium due to [Constantinos Daskalakis, Paul W. Goldberg, Christos H. Papadimitriou, The complexity of computing a Nash equilibrium, SIAM Journal on Computing (in press) Preliminary version appeared in STOC (2006)] no nontrivial bound is known; we show that the problem can be reduced to the case of win-lose games (games with all utilities 0 or 1), and that an approximation of 56 is possible, contingent upon a graph-theoretic conjecture. Subsequent work extends the 14 impossibility result of Ingo Althofer's paper, as mentioned above, to 12 [Tomas Feder, Hamid Nazerzadeh, Amin Saberi, Approximating nash equilibria using small-support strategies, in: EC, 2007], making our 12-approximate Nash equilibrium algorithm optimal among the algorithms that only consider mixed strategies of sublogarithmic size support. Moreover, techniques similar to our techniques for approximately well supported Nash equilibria are used in [Spyros Kontogiannis, Paul G. Spirakis, Efficient algorithms for constant well supported approximate equilibria in bimatrix games, in: ICALP, 2007] for obtaining an efficient algorithm for 0.658-approximately well supported Nash equilibria, unconditionally.
Relational concurrent refinement part II: Internal operations and outputs
Authors: Eerke Boiten, John Derrick, Gerhard Schellhorn
Venue: Formal Aspects of Computing (2009)

Two styles of description arise naturally in formal specification: state-based and behavioural. In state-based notations, a system is characterised by a collection of variables, and their values determine which actions may occur throughout a system history. Behavioural specifications describe the chronologies of actions&#x2014;interactions between a system and its environment. The exact nature of such interactions is captured in a variety of semantic models with corresponding notions of refinement; refinement in state based systems is based on the semantics of sequential programs and is modelled relationally. Acknowledging that these viewpoints are complementary, substantial research has gone into combining the paradigms. The purpose of this paper is to do three things. First, we survey recent results linking the relational model of refinement to the process algebraic models. Specifically, we detail how variations in the relational framework lead to relational data refinement being in correspondence with traces&#x2013;divergences, singleton failures and failures&#x2013;divergences refinement in a process semantics. Second, we generalise these results by providing a general flexible scheme for incorporating the two main &#x201c;erroneous&#x201d; concurrent behaviours: deadlock and divergence, into relational refinement. This is shown to subsume previous characterisations. In doing this we derive relational refinement rules for specifications containing both internal operations and outputs that corresponds to failures&#x2013;divergences refinement. Third, the theory has been formally specified and verified using the interactive theorem prover KIV.
An optimal overlay topology for routing peer-to-peer searches
Authors: Brian F. Cooper
Venue: Proceedings of the ACM/IFIP/USENIX 2005 International Conference on Middleware (2005)

Unstructured peer-to-peer networks are frequently used as the overlay in various middleware toolkits for emerging applications, from content discovery to query result caching to distributed collaboration. Often it is assumed that unstructured networks will form a power-law topology; however, a power-law structure is not the best topology for an unstructured network. In this paper, we introduce the square-root topology, and show that this topology significantly improves routing performance compared to power-law networks. In the square-root topology, the degree of a peer is proportional to the square root of the popularity of the content at the peer. Our analysis shows that this topology is optimal for random walk searches. We also present simulation results to demonstrate that the square-root topology is better, by up to a factor of two, than a power-law topology for other types of search techniques besides random walks. We then describe a decentralized algorithm for forming a square-root topology, and evaluate its effectiveness in constructing efficient networks using both simulations and experiments with our implemented prototype. Our results show that the square-root topology can provide a significant performance improvement over power-law topologies and other topology types.