ppxscal/embedding_network huggingface dataset:
An algorithm for automatic generation of fuzzy neural network based on perception frames
Authors: Aleksandar Milosavljevic, Leonid Stoimenov, Dejan Rančic
Venue: Proceedings of the 9th WSEAS International Conference on Neural Networks (2008)

In this paper we present an algorithm for automatic generation of fuzzy neural networks (FNN). Fuzzy neural networks are concept that integrates some features of the fuzzy logic and the artificial neural networks theory. Based on analysis of several different fuzzy neural networks models, uniform representation method is presented, and two basic types are identified: FNN based on perception frames, and FNN with independent rules. Presented algorithm supports rule generation of fuzzy neural network based on perception frames, while training for adaptation relies on gradient decent method, i.e. modified backpropagation algorithm.
Switched and PieceWise Nonlinear Hybrid System Identification
Authors: Fabien Lauer, Gérard Bloch
Venue: Proceedings of the 11th international workshop on Hybrid Systems: Computation and Control (2008)

Hybrid system identification aims at both estimating the discrete state or mode for each data point, and the submodel governing the dynamics of the continuous state for each mode. The paper proposes a new method based on kernel regression and Support Vector Machines (SVM) to tackle this problem. The resulting algorithm is able to compute both the discrete state and the submodels in a single step, independently of the discrete state sequence that generated the data. In addition to previous works, nonlinear submodels are also considered, thus extending the class of systems on which the method can be applied from PieceWise Affine (PWA) and switched linear to PieceWise Smooth (PWS) and switched nonlinear systems with unknown nonlinearities. Piecewise systems with nonlinear boundaries between the modes are also considered with some preliminary results on this issue.
Polynomial Distinguishability of Timed Automata
Authors: Sicco Verwer, Mathijs Weerdt, Cees Witteveen
Venue: Proceedings of the 9th international colloquium on Grammatical Inference: Algorithms and Applications (2008)

We study the complexity of identifying (learning) timed automata in the limit from data. Timed automata are finite state models that model time explicitly, i.e., using numbers. Because timed automata use numbers to represent time, they can be exponentially more compact than models that model time implicitly, i.e., using states.We show three results that are essential in order to exactly determine when timed automata are efficiently identifiable in the limit. First, we show that polynomial distinguishability is a necessary condition for efficient identifiability in the limit. Second, we prove that deterministic time automata with two or more clocks are not polynomially distinguishable. As a consequence, they are not efficiently identifiable. Last but not least, we prove that deterministic timed automata with one clock are polynomially distinguishable, which makes them very likely to be efficiently identifiable in the limit.
Approximating List-Coloring on a Fixed Surface
Authors: Ken-Ichi Kawarabayashi
Venue: Proceedings of the 35th international colloquium on Automata, Languages and Programming, Part I (2008)

It is well-known that approximating the chromatic number within a factor of n 1 ¿ ¿ cannot be done in polynomial time for any ¿> 0, unless coRP = NP. Also, it is known that computing the list-chromatic number is much harder than the chromatic number (assuming that the complexity classes NP and coNP are different). In fact, the problem of deciding if a given graph is f-list-colorable for a function f : V ¿{k ¿ 1,k} for k ¿ 3 is ¿ 2 p -complete.In this paper, we are concerned with the following questions: 1 Given a graph embedded on a surface of bounded genus, what is its list-chromatic number ? 1 Given a graph embedded on a surface of bounded genus with list-chromatic number k, what is the least l (l ¿ k) such that the graph can be efficiently and legally colored given a list (coloring scheme) of order l ? The seminal result of Thomassen [19] gives rise to answers for these problems when a given graph is planar. In fact, he gave a polynomial time algorithm to 5-list-color a planar graph. Thomassen's result together with the hardness result (distinguishing between 3, 4 and 5 list-colorability is NP-complete for planar graphs and bounded genus graphs) gives an additive approximation algorithm for list-coloring planar graphs within 2 of the list-chromatic number.Our main result is to extend this result to bounded genus graphs. In fact, our algorithm gives a list-coloring when each vertex has a list with at least ¿ l (G) + 2 colors available. The time complexity is O(n).It also generalizes the other deep result of Thomassen [20] who gave an additive approximation algorithm for graph-coloring bounded genus graphs within 2 of the chromatic number.This theorem can be compared to the result by Kawarabayashi and Mohar(STOC'06) who gave an O(k)-approximation algorithm for list-coloring graphs with no K k -minors. For minor-closed graphs, there is a 2-approximation algorithm for graph-coloring by Demaine, Hajiaghayi and Kawarabayashi (FOCS'05), but it seems that there is a huge gap between list-coloring and graph-coloring in minor-closed family of graphs. On the other hand, this is not the case for bounded genus graphs, as we pointed out above.
DIChirp: direct injection bandwidth estimation
Authors: Yusuf Ozturk, Manish Kulkarni
Venue: International Journal of Network Management (2008)

Ideally, network bandwidth estimation algorithms should be independent of the end system performance. If end system capabilities are involved, then the measurement will be of the system throughput and will not indicate a correct assessment of network bandwidth. Packet dispersion-based active bandwidth estimation schemes including Pathload, TOPP and pathChirp use delay correlation where the network-induced delay on packets transmitted at certain rates is translated into bandwidth estimation. Since packet dispersion-based active measurement schemes use delay correlation, bandwidth estimations are distorted by the host protocol stack-induced delay variations. Studies revealed that the host protocol stack-induced delay variations due to context switching are stovepiped in the network-induced delay variations and impact the measurement process. This study explores the delay variations introduced by the host protocol stack in packet dispersion-based techniques. The impact of host protocol delay variations and context switching on bandwidth estimation is analyzed and a new active bandwidth estimation tool minimizing the impact of context switching is proposed. Direct Injection Chirp (DIChirp) bypasses the TCP/IP protocol stack and directly interfaces with the network hardware. It uses the kernel for scheduling the outgoing packets, thus achieving more accurate estimation of bandwidth. Experiments revealed that the host protocol and context switching-induced delay variations can be as high as 800µs and could result in bandwidth estimation errors near 20%. Experiments also revealed that the DIChirp is superior to the pathChirp implementation in performance estimation since the datapath utilized by DIChirp is less prone to delay variations induced by context switching.
GEP-Induced Expression Trees as Weak Classifiers
Authors: Joanna Jedrzejowicz, Piotr Jedrzejowicz
Venue: Proceedings of the 8th industrial conference on Advances in Data Mining: Medical Applications, E-Commerce, Marketing, and Theoretical Aspects (2008)

The paper proposes applying Gene Expression Programming (GEP) to induce expression trees used subsequently as weak classifiers. Two techniques of constructing ensemble classifiers from weak classifiers are investigated in the paper. The working hypothesis of the paper can be stated as follows: given a set of classifiers generated through applying gene expression programming method and using some variants of boosting technique, one can construct the ensemble producing effectively high quality classification results. A detailed description of the proposed GEP implementation generating classifiers in the form of expression trees is followed by the report on AdaBoost and boosting algorithms used to construct an ensemble classifier. To validate the approach computational experiment involving several benchmark datasets has been carried out. Experiment results show that using GEP-induced expression trees as weak classifiers allows for construction of a high quality ensemble classifier outperforming, in terms of classification accuracy, many other recently published solutions.
Using Interaction Analysis to Reveal Self-Regulated Learning in Virtual Communities
Authors: Giuliana Dettori, Donatella Persico
Venue: Proceedings of the 3rd European conference on Technology Enhanced Learning: Times of Convergence: Technologies Across Learning Contexts (2008)

Aim of this paper is to analyse whether Interaction Analysis can help investigate the practice and development of Self-Regulated Learning (SRL) in Virtual Learning Communities (VLC). Interaction analysis is increasingly used to study learning dynamics within online activities. It proceeds by searching expressions that reveal the aspects under study in the written messages exchanged by the learners. To this end, we devised and classified a number of indicators suggesting the existence of self-regulated events, and tested this approach on the online component of a blended course for trainee teachers. We analysed the messages exchanged by a group of learners in two modules of the course and compared the results with those of a previous study carried out with more traditional methods. The similarity of the results obtained by the two approaches suggests that Interaction Analysis is an effective, though rather labour-intensive, way to study SRL in VLCs.
Analysis of an algebraic Petrov--Galerkin smoothed aggregation multigrid method
Authors: Hervé Guillard, Aleš Janka, Petr Vaněk
Venue: Applied Numerical Mathematics (2008)

We give a convergence estimate for a Petrov-Galerkin Algebraic Multigrid method. In this method, the prolongations are defined using the concept of smoothed aggregation while the restrictions are simple aggregation operators. The analysis is carried out by showing that these methods can be interpreted as variational Ritz-Galerkin ones using modified transfer and smoothing operators. The estimate depends only on a weak approximation property for the aggregation operators. For a scalar second order elliptic problem using linear elements, this assumption is shown to hold using simple geometrical arguments on the aggregates.
Effect of Groove Shape on Flow Characteristics around a Circular Cylinder with Grooves
Authors: Y. Yamagishi, M. Oki
Venue: Journal of Visualization (2004)

In the flow around a circular cylinder, a sudden decrease in the drag force occurs at a high Reynolds number, but the same phenomenon occurs at a lower Reynolds number in the case where there exist grooves or roughness on the circular cylinder surface. In this paper, in order to make clear the flow characteristics around a circular cylinder in the case of changing the shapes of grooves, the drag coefficient, pressure distribution, velocity distribution and turbulent distribution were measured. Moreover the flow around the cylinder was analyzed by applying the RNG k &minus;ε turbulent model, and the surface flow pattern was investigated using the oil-film technique. From these results, it is clear that the drag coefficient of a circular cylinder with triangular grooves decreases by about 15% compared with that of a circular cylinder with arc grooves.
Proceedings of the 9th workshop on Mobile computing systems and applications
Venue: Workshop on Mobile Computing Systems and Applications (2008)

HotMobile 2008: The Workshop on Mobile Computing Systems and Applications continues to serve as the premier venues for workshop style results in the areas of mobile systems and computing. We received 79 submissions for the workshop, an increase of 65% increase over the 48 submissions in 2007. After through review we accepted 18 papers to appear at the workshop, for a 22% acceptance rate. This year, HotMobile joins the ACM family transitioning form its roots as an IEEE Workshop. This further strengthens the growing ties with the ACM SIGMOBILE conference MobiSys. It is our hope that early work that appears in HotMobile will eventually appear at MobiSys.
On Classifying Disease-Induced Patterns in the Brain Using Diffusion Tensor Images
Authors: Peng Wang, Ragini Verma
Venue: Proceedings of the 11th international conference on Medical Image Computing and Computer-Assisted Intervention - Part I (2008)

Diffusion tensor imaging (DTI) provides rich information about brain tissue structure especially in the white matter, which is known to be affected in several diseases like schizophrenia. Identifying patterns of brain changes induced by pathology is therefore crucial to clinical studies. However, the high dimensionality and complex structure of DTI make it difficult to apply conventional linear statistical and pattern classification methods to identify such patterns. In this paper, we present a novel framework that uses a combination of DTI-based anisotropy and geometry features to effectively identify brain regions with pathology-induced abnormality, and to classify brains into the diseased and healthy groups. Our method first directly estimates the underlying overlap between the patient and control groups, based on a semi-parametric Bayes error estimation method. By ranking voxels based on these estimation results, the method identifies abnormal brain regions from which features are extracted through Kernel Principal Component Analysis (KPCA) for subsequent classification. Application of the method to a dataset of controls and patients with schizophrenia, demonstrates promising accuracy of this framework in identifying brain patterns to separate two groups, and hence aiding in prognosis and treatment.
Fault Tolerant Schemes for Hot-Swappable and Non Hot-Swappable Mezzanine Cards
Authors: Mark Lanus
Venue: Proceedings of the 4th international symposium on Service Availability (2007)

First generation, highly-available computer systems deployed a two-level physical hierarchy whereby a shelf was composed of field replaceable units (FRU) and the unit of fault detection, fault isolation, fault containment, fault recovery, fault repair, and sparing was the FRU. In 1995, IEEE introduced the non hot-swappable PCI Mezzanine Card (PMC) draft standard [1] that allows fault detection, isolation, containment, recovery, and sparing to be implemented at the mezzanine card level but requires fault repair to occur at the carrier board level. In 2005 the PCI Industrial Computer Manufacturers Group (PICMG®) introduced the hot swappable Advanced Mezzanine Card (AMC) standard [2] that extends the PMC model to allow all fault management functions, including fault repair, to be implemented at the mezzanine card level. This paper develops fault management strategies and availability models for the monolithic, non hot swap partitioned, and hot swap partitioned hardware architectures.
Performance evaluation of active route time-out parameter in ad-hoc on demand distance vector (AODV)
Authors: Wadhah Al-Mandhari, Koichi Gyoda, Nobuo Nakajima
Venue: Proceedings of the 6th WSEAS International Conference on Applied Electromagnetics, Wireless and Optical (2008)

Ad-hoc mobile networks routing protocol play an important role in the performance of the network. The Route states hold time parameter in routing protocols has a direct effect on the packet delivery rate. Moreover, the number of stations and their movement speed in the network also has an effect on the network performance. Our aim is to identify the effect of varying Route states hold time parameters for Ad-hoc On Demand Distance Vector (AODV) routing protocol and to measure the degree at which the number of stations and their movement speeds will affect the packet delivery rate. These factors are presented, discussed and simulated using OPNET simulation software.
Colocatedness and Lebesgue Integrability
Authors: Douglas S. Bridges
Venue: Proceedings of the 3rd conference on Computability in Europe: Computation and Logic in the Real World (2007)

With reference to Mandelkern's characterisation of colocated subsets of the line in constructive analysis, we introduce the notion of "strongly colocated set" and find conditions under which such a set is Lebesgue integrable.
Quadratic Stability of Discrete-Time Switched Systems
Authors: Chunming Li, Xiaohua Liu
Venue: Proceedings of the 2008 Congress on Image and Signal Processing, Vol. 5 - Volume 05 (2008)

Quadratic stability of switched systems consisting of a class of m-discrete subsystems is studied. An interval matrix is constructed to transform the discrete-time switched system into interval system. Then, a sufficient condition is presented in terms of linear matrix inequality for the quadratic stability of discrete-time switched systems under arbitrary switching laws. This condition is much simpler than the other methods because it needs only one linear matrix inequality to solve. A numerical example illustrates the effectiveness of the method.
Adaptation of Elaborated Feedback in e-Learning
Authors: Ekaterina Vasilyeva, Mykola Pechenizkiy, Paul Bra
Venue: Proceedings of the 5th international conference on Adaptive Hypermedia and Adaptive Web-Based Systems (2008)

Design of feedback is a critical issue of online assessment development within Web-based Learning Systems (WBLSs). In our work we demonstrate the possibilities of tailoring the feedback to the students' learning style (LS), certitude in response and its correctness. We observe in the experimental studies that these factors have a significant influence on the feedback preferences of students and the effectiveness of elaborated feedback (EF), i.e. students' performance improvement during the test. These observations helped us to develop a simple EF recommendation approach. Our experimental study shows that (1) many students are eager to follow the recommendations on necessity to read certain EF in the majority of cases; (2) the students more often find the recommended EF to be useful, and (3) the recommended EF helped to answer related questions better.
Optimum shape design for turbulent viscous flows around complete configurations of 2D flying sails
Authors: Mattia de' Michieli Vitturi, François Beux, Giovanni Lombardi, Alain Dervieux
Venue: Journal of Computational Methods in Sciences and Engineering (2004)

Optimization of a complete 2D flying sails configuration is considered. An optimum shape design problem is then defined considering the maximization of the drive force on the sails and a complete flow modelling including accurate turbulent effects. The corresponding numerical algorithm is based on a gradient descent method coupled with a discrete shape grid-point parametrization. The descent direction is obtained by an exact computation of an incomplete discrete gradient associated with a multi-level strategy. The numerical behavior of the present formulation has been illustrated by the optimization of a real 2D configuration of an America's Cup yacht.
Semi-autonomous Servers in Wireless Cellular Networks
Authors: John Tsiligaridis
Venue: Proceedings of the 2008 The Third International Multi-Conference on Computing in the Global Information Technology (iccgi 2008) (2008)

An innovative framework for the management of server services at various sites across a communication network is presented. It consists of a better organization of queries' plan and data allocation to server, considering the group and query mobility along with the dependency of servers. Nowadays servers' ability to work semi autonomously, in regards to the decision of the appropriate query plan and the provision of the effective data location, plays a significant role to the query and network performance. Our objective is to minimize the communication and execution cost of the query plan for the dependent servers (when the query can not be completed in the starting servers) servers having query and group mobility. Data Mining methods are applied to reduce the dependent servers' external queries. A set of direct executing methods for starting the query server enforces the semi-autonomous server process. Simulation results are provided.
Annotation of Emotion in Dialogue: The Emotion in Cooperation Project
Authors: Federica Cavicchio, Massimo Poesio
Venue: Proceedings of the 4th IEEE tutorial and research workshop on Perception and Interactive Technologies for Speech-Based Systems: Perception in Multimodal Dialogue Systems (2008)

In this research we investigate the relationship between emotion and cooperation in dialogue tasks. It is an area were still many unsolved questions are present. One of the main open issues is the labeling of "blended" emotions and their recognition. Usually there is a low agreement among raters in labeling and naming emotions and surprisingly emotion recognition is higher in a condition of modality deprivation (only acoustic or only visual vs. bimodal). Because of this previous results we don't ask raters to directly label emotions, but to use a small set of features (as lips or eyebrows shape) to annotate our corpus. The analyzed materials come from an audiovisual corpus of Map Task dialogues elicited with a script. We point out the "emotive" tokens by simultaneous recordings of the phsychophysiological indexes (ElectroCardioGram ECG, Galvanic Skin Conductance GSC, ElectroMyoGraphy EMG). After this selection we annotate each token with our multimodal annotation scheme. Each annotation will lead to a cluster of signals identifying the emotion corresponding to a cooperative/non cooperative level; the last step involves agreement among coders and reliability of the emotion description. Future research will deal with brain imaging experiment on the effect of putting emotions into words and the role of context in emotion recognition.
Identification of a periodic time series from an environmental proxy record
Authors: Anouk de Brauwere, Fjo De Ridder, Rik Pintelon, Jeroen Meersmans, Johan Schoukens, Frank Dehairs
Venue: Computers Geosciences (2008)

The past environment is often reconstructed by measuring a certain proxy (e.g. @d^1^8O) in an environmental archive, i.e. a species that gradually accumulates mass and records the current environment during this mass formation (e.g. corals, shells, trees, etc.). When such an environmental proxy is measured, its values are known on a distance grid. However, to relate the data to environmental variations, the date associated with each measurement has to be known too. This transformation from distance to time is not straightforward to solve, since species usually do not grow at constant or known rates. In this paper, we investigate this problem for environmental archives exhibiting a certain periodicity. In practice, the method will be applicable to most annually resolved archives because these contain a seasonal component, e.g. clams, corals, sediment cores or trees. Due to variations in accretion rate the data along the distance axis have a disturbed periodic profile. In this paper, a method is developed to extract information about the accretion rate, such that the original (periodic, but further unknown) signal as a function of time can be recovered. The final methodology is quasi-independent of choices made by the investigator and is designed to deliver the most precise and accurate result. Every step in the procedure is described in detail, the results are tested on a Monte-Carlo simulation, and finally the method is exemplified on a real world example.