ppxscal/embedding_network huggingface dataset:
Decomposition and Classification of Spectral Lines in Astronomical Radio Data Cubes
Authors: Vincent Mazet, Christophe Collet, Bernd Vollmer
Venue: Proceedings of the 16th Scandinavian Conference on Image Analysis (2009)

The natural output of imaging spectroscopy in astronomy is a 3D data cube with two spatial and one frequency axis. The spectrum of each image pixel consists of an emission line which is Doppler-shifted by gas motions along the line of sight. These data are essential to understand the gas distribution and kinematics of the astronomical object. We propose a two-step method to extract coherent kinematic structures from the data cube. First, the spectra are decomposed into a sum of Gaussians using a Bayesian method to obtain an estimation of spectral lines. Second, we aim at tracking the estimated lines to get an estimation of the structures in the cube. The performance of the approach is evaluated on a real radio-astronomical observation.
Uncovering cognitive processes: cued retrospective reporting based on eye-movement records
Authors: Tamara Van Gog, Saskia Brand-Gruwel, Ludo Van Meeuwen, Fred Paas
Venue: Proceedings of the 8th international conference on International conference for the learning sciences - Volume 3 (2008)

The verbal reporting techniques used most in research on learning and instruction, concurrent and retrospective reporting, both have drawbacks. Retrospective reporting often results in omissions/fabrications, and concurrent reporting is difficult to implement when tasks impose high cognitive load or contain auditory information. Cued retrospective reporting (CRR) based on eye-movement records might be able to overcome these drawbacks: while maintaining the retrospective nature, the cue shows both physical (mouse/keyboard) and cognitive (eye movements) actions, thereby presumably leading to less omissions/fabrications. Because a previous study showed promising results, the present study extends the test of CRR to qualitative data (i.e., process coverage).
Some Characterizations of Parseval Frame Wavelet
Authors: Guochang Wu, Junmin Wang
Venue: Proceedings of the 2009 International Conference on Computational Intelligence and Natural Computing - Volume 02 (2009)

This paper characterizes all generalized low pass filters and MRAParseval frame wavelets in $L^2(R^n)$ with matrixdilations of the form $(D f )(x) =\sqrt{2}f (Ax)$,where $A$ is an arbitrary expanding $n\times n$ matrix with integer coefficients,such that $|detA| =2$. The pseudo-scaling functions, generalized low pass filters and MRA Parseval frame wavelets are studied and some important properties about them are given.
Structure Tensor of Colour Quaternion Image Representations for Invariant Feature Extraction
Authors: Jesús Angulo
Venue: Computational Color Imaging: Second International Workshop, CCIW 2009, Saint-Etienne, France, March 26-27, 2009. Revised Selected Papers (2009)

Colour image representation using real quaternions has shown to be very useful for linear and morphological colour filtering. This paper deals with the extension of first derivatives-based structure tensor for various quaternionic colour image representations. Classical corner and edge features are obtained from eigenvalues of the quaternionic colour structure tensors. We study the properties of invariance of the quaternion colour spatial derivatives and their robustness for feature extraction on practical examples. 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
Short-Range Wireless Communications: Emerging Technologies and Applications
Authors: Rolf Kraemer, Marcos Katz
Venue:  (2009)

This unique book reviews the future developments of short-range wireless communication technologies Short-Range Wireless Communications: Emerging Technologies and Applications summarizes the outcomes of WWRF Working Group 5, highlighting the latest research results and emerging trends on short-range communications. It contains contributions from leading research groups in academia and industry on future short-range wireless communication systems, in particular 60 GHz communications, ultra-wide band (UWB) communications, UWB radio over optical fiber, and design rules for future cooperative short-range communications systems. Starting from a brief description of state-of-the-art, the authors highlight the perspectives and limits of the technologies and identify where future research work is going to be focused. Key Features: Provides an in-depth coverage of wireless technologies that are about to start an evolution from international standards to mass products, and that will influence the future of short-range communications Offers a unique and invaluable visionary overview from both industry and academia Identifies open research problems, technological challenges, emerging technologies, and fundamental limits Covers ultra-high speed short-range communication in the 60 GHz band, UWB communication, limits and challenges, cooperative aspects in short-range communication and visible light communications, and UWB radio over optical fiber This book will be of interest to research managers, R&D engineers, lecturers and graduate students within the wireless communication research community. Executive managers and communication engineers will also find this reference useful.
The computational status of physics
Authors: Mike Stannett
Venue: Natural Computing: an international journal (2009)

According to the Church-Turing Thesis (CTT), effective formal behaviours can be simulated by Turing machines; this has naturally led to speculation that physical systems can also be simulated computationally. But is this wider claim true, or do behaviours exist which are strictly hypercomputational? Several idealised computational models are known which suggest the possibility of hypercomputation, some Newtonian, some based on cosmology, some on quantum theory. While these models' physicality is debatable, they nonetheless throw into question the validity of extending CTT to include all physical systems. We consider the physicality of hypercomputational behaviour from first principles, by showing that quantum theory can be reformulated in a way that explains why physical behaviours can be regarded as `computing something' in the standard computational state-machine sense. While this does not rule out the physicality of hypercomputation, it strongly limits the forms it can take. Our model also has physical consequences; in particular, the continuity of motion and arrow of time become theorems within the basic model.
Ambiguous decision trees for mining concept-drifting data streams
Authors: Jing Liu, Xue Li, Weicai Zhong
Venue: Pattern Recognition Letters (2009)

In real world situations, explanations for the same observations may be different depending on perceptions or contexts. They may change with time especially when concept drift occurs. This phenomenon incurs ambiguities. It is useful if an algorithm can learn to reflect ambiguities and select the best decision according to context or situation. Based on this viewpoint, we study the problem of deriving ambiguous decision trees from data streams to cope with concept drift. CVFDT (Concept-adapting Very Fast Decision Tree) is one of the most well-known streaming data mining methods that can learn decision trees incrementally. In this paper, we establish a method called ambiguous CVFDT (aCVFDT), which integrates ambiguities into CVFDT by exploring multiple options at each node whenever a node is to be split. When aCVFDT is used to make class predictions, it is guaranteed that the best and newest knowledge is used. When old concepts recur, aCVFDT can immediately relearn them by using the corresponding options recorded at each node. Furthermore, CVFDT does not automatically detect occurrences of concept drift and only scans trees periodically, whereas an automatic concept drift detecting mechanism is used in aCVFDT. In our experiments, hyperplane problem and two benchmark problems from the UCI KDD Archive, namely Network Intrusion and Forest CoverType, are used to validate the performance of aCVFDT. The experimental results show that aCVFDT obtains significantly improved results over traditional CVFDT.
On least squares estimation for long-memory lattice processes
Authors: Jan Beran, Sucharita Ghosh, Dieter Schell
Venue: Journal of Multivariate Analysis (2009)

A flexible class of anisotropic stationary lattice processes with long memory can be defined in terms of a two-way fractional ARIMA (FARIMA) representation. We consider parameter estimation based on minimizing an approximate residual sum of squares. The method can be applied to sampling areas that are not necessarily rectangular. A central limit theorem is derived under general conditions. The method is illustrated by an analysis of satellite data consisting of total column ozone amounts in Europe and the Atlantic respectively.
A SPN-Based Performance Evaluation of Wireless Sensor Networks
Authors: Wu Zeng, Zhiguo Hong
Venue: Proceedings of the 2009 Second International Symposium on Electronic Commerce and Security - Volume 02 (2009)

On the basis of communication process a Stochastic Petri Net (SPN) model is constructed to analyze the performance of Wireless Sensor Networks (WSNs). The effects of arrival rate, data packet number, sink node's buffer size on average time delay, throughput and the utilization of the sink node buffer are also analyzed by solving the linear equations from corresponding isomorphic Markov Chains of the SPN model under different parameters. The proposed approach has great benefit to the design and performance evaluation of WSNs.
New exponentially convergent state estimation method for delayed neural networks
Authors: Magdi S. Mahmoud
Venue: Neurocomputing (2009)

The problem of designing a globally exponentially convergent state estimator for a class of delayed neural networks is investigated in this paper. The time-delay pattern is quite general and including fast time-varying delays. The activation functions are monotone nondecreasing with known lower and upper bounds. A linear estimator of Luenberger-type is developed and by properly constructing a new Lyapunov-Krasovskii functional coupled with the integral inequality, the global exponential stability conditions of the error system are derived. The unknown gain matrix is determined by solving a delay-dependent linear matrix inequality. The developed results are shown to be less conservative than previously published ones in the literature, which is illustrated by a representative numerical example.
A new R package for Bayesian estimation of multivariate normal mixtures allowing for selection of the number of components and interval-censored data
Authors: Arnošt Komárek
Venue: Computational Statistics Data Analysis (2009)

An R package mixAK is introduced which implements routines for a semiparametric density estimation through normal mixtures using the Markov chain Monte Carlo (MCMC) methodology. Besides producing the MCMC output, the package computes posterior summary statistics for important characteristics of the fitted distribution or computes and visualizes the posterior predictive density. For the estimated models, penalized expected deviance (PED) and deviance information criterion (DIC) is directly computed which allows for a selection of mixture components. Additionally, multivariate right-, left- and interval-censored observations are allowed. For univariate problems, the reversible jump MCMC algorithm has been implemented and can be used for a joint estimation of the mixture parameters and the number of mixture components. The core MCMC routines have been implemented in C++ and linked to R to ensure a reasonable computational speed. We briefly review the implemented algorithms and illustrate the use of the package on three real examples of different complexity.
On-Demand Associative Cross-Language Information Retrieval
Authors: André Pinto Geraldo, Viviane P. Moreira, Marcos A. Gonçalves
Venue: Proceedings of the 16th International Symposium on String Processing and Information Retrieval (2009)

This paper proposes the use of algorithms for mining association rules as an approach for Cross-Language Information Retrieval. These algorithms have been widely used to analyse market basket data. The idea is to map the problem of finding associations between sales items to the problem of finding term translations over a parallel corpus. The proposal was validated by means of experiments using queries in two distinct languages: Portuguese and Finnish to retrieve documents in English. The results show that the performance of our proposed approach is comparable to the performance of the monolingual baseline and to query translation via machine translation, even though these systems employ more complex Natural Language Processing techniques. The combination between machine translation and our approach yielded the best results, even outperforming the monolingual baseline.
A fully redundant decimal adder and its application in parallel decimal multipliers
Authors: Saeid Gorgin, Ghassem Jaberipur
Venue: Microelectronics Journal (2009)

Decimal hardware arithmetic units have recently regained popularity, as there is now a high demand for high performance decimal arithmetic. We propose a novel method for carry-free addition of decimal numbers, where each equally weighted decimal digit pair of the two operands is partitioned into two weighted bit-sets. The arithmetic values of these bit-sets are evaluated, in parallel, for fast computation of the transfer digit and interim sum. In the proposed fully redundant adder (VS semi-redundant ones such as decimal carry-save adders) both operands and sum are redundant decimal numbers with overloaded decimal digit set [0, 15]. This adder is shown to improve upon the latest high performance similar works and outperform all the previous alike adders. However, there is a drawback that the adder logic cannot be efficiently adapted for subtraction. Nevertheless, this adder and its restricted-input varieties are shown to efficiently fit in the design of a parallel decimal multiplier. The two-to-one partial product reduction ratio that is attained via the proposed adder has lead to a VLSI-friendly recursive partial product reduction tree. Two alternative architectures for decimal multipliers are presented; one is slower, but area-improved, and the other one consumes more area, but is delay-improved. However, both are faster in comparison with previously reported parallel decimal multipliers. The area and latency comparisons are based on logical effort analysis under the same assumptions for all the evaluated adders and multipliers. Moreover, performance correctness of all the adders is checked via running exhaustive tests on the corresponding VHDL codes. For more reliable evaluation, we report the result of synthesizing these adders by Synopsys Design Compiler using TSMC 0.13@mm standard CMOS process under various time constrains.
Testing for independence in heavy-tailed time series using the codifference function
Authors: Dedi Rosadi
Venue: Computational Statistics Data Analysis (2009)

In this paper, we consider a Portmanteau-type test of randomness for symmetric @a stable random variables with exponent 0
Calibration of Rotating Sensors
Authors: Karsten Scheibe, Fay Huang, Reinhard Klette
Venue: Proceedings of the 13th International Conference on Computer Analysis of Images and Patterns (2009)

This paper reports about a method for calibrating rotating senors, namely, rotating sensor-line cameras and laser range-finders. Both together are used to reconstruct accurately 3D environments, such as, for example, large buildings. One of the important steps in the 3D reconstruction pipeline is the fusion of data. This requires an understanding of spatial relationships among the acquired data. Sensor calibration is the key to accurate 3D models. 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 Low Power High Performance Radix-4 Approximate Squaring Circuit
Authors: Satyendra R. Datla, Mitchell A. Thornton, David W. Matula
Venue: Proceedings of the 2009 20th IEEE International Conference on Application-specific Systems, Architectures and Processors (2009)

An implementation of a radix-4 approximate squaring circuit is described employing a new operand dual recoding technique. Approximate squaring circuits have numerous applications including use in computer graphics, digital radio modules, implementation of division and function approximation in ALU circuits. The theory of operation of the circuit is described including radix-4 operand dual recoding. Our recoding yields non negative partial squares and other features which simplify the design of the approximate squaring circuit. Results of the implementation in terms of delay, power, and area in both 130nm and 90nm technologies are presented and analyzed. The results show the circuit is power, area and performance efficient, yielding reduction factors by three or more when compared to a truncated multiplication approach using state-of-the-art logic synthesis tools. The radix-4 squaring circuit is also shown to be more efficient than a radix-2 state-of-the-art binary squaring circuit.
Making classrooms socio-technical environments for supporting collaborative learning: the role of personal devices and boundary objects
Authors: Chen-Chung Liu, Chen-Wei Chung, Shu-Yuan Tao
Venue: Proceedings of the 9th international conference on Computer supported collaborative learning - Volume 1 (2009)

The emergence of low-price computers has made possible numerous new ways of classroom learning. The personal devices that are applied in a manner without interoperation with appropriate peripherals may interfere with face-to-face collaboration since the personal devices were design for personal usages. To improve the collaboration that takes place in small face-to-face groups in repeated episodes, we seek to strengthen relationships by encouraging non-verbal contact, which is known to be a key component to increasing intimacy in personal relationships. Through gathering the small group learning interactions in a collaborative learning scenario, this study proposed that classroom environments require, in addition to personal devices, special design of boundary objects to sustain and support social learning activities. An experimental classroom was developed with LCD displays and shared-display groupware. Analysis of student learning activity found that students working with only personal devices tended to learn together in a disjoint interaction pattern. Contrarily, in the environment with shared-displays as boundary objects students demonstrated a joint and coherent interaction pattern since they took more notice of the shared group work.
The Fuzzy-PI Control of Switched Reluctance Motor Based on DTC
Authors: Mianhua Wang
Venue: Proceedings of the 2009 International Conference on Measuring Technology and Mechatronics Automation - Volume 02 (2009)

A strategy of fuzzy-PI control of switched reluctance motor drive system is presented. The strategy of fuzzy and PI is combined to realize the speed adjustment. The outer loop input is speed error and speed error derivative, while the outer loop output is torque which enters the inner loop of the direct torque control system to control 60KW three phase 6/4 pole SRM. For the outer loop, it adopts fuzzy control when the speed error is big, and adopts PI control when the error is small. Simulation results indicate that this compound control strategy can settle the parameter which is hard to be determined caused by inaccurate motor model, and it overcomes the steady-state error of speed in classical fuzzy controller, and the paradox between the response time and overshoot of speed is managed. The system has a good anti-interference performance.
Logic and Integer Programming, 1st edition
Authors: H. Paul Williams
Venue:  (2009)

Integer programming (discrete optimization) is best used for solving problems involving discrete, whole elements. Using integer variables, one can model logical requirements, fixed costs, sequencing and scheduling requirements, and many other problem aspects. Whether its taught in OR graduate programs or in math or computer science programs; in courses called "Integer Programming," "Combinatorial Optimization," "Combinatorial Optimization and Integer Programming" or simply "Advanced Operations Management," its a part of every OR curriculum, and one of its greatest teachers has developed a text that shows how to use logic in integer programming to develop models with much greater precision. Paul Williams, a leading authority on modeling in integer programming, has written a concise, readable introduction to the science and art of using modeling in logic for integer programming. Written for graduate and postgraduate students, as well as academics and practitioners, the book is divided into four chapters that all avoid the typical format of definitions, theorems and proofs and instead introduce concepts and results within the text through examples. References are given at the end of each chapter to the more mathematical papers and texts on the subject, and exercises are included to reinforce and expand on the material in the chapter. Chapter 1 gives a basic introduction to logic and its aims, and goes on to explain the Propositional and Predicate Calculus. Chapter 2 explains Linear Programming (LP) and Integer Programming (IP) using the machinery of logic; explains the fundamental structural and mathematical properties of these types of models, along with the main methods of solving IP models; covers main areas of practical application; and attempts to distinguish between computationally difficult and easy classes of problem. Chapter 3 applies logic to the formulation of IP models using the methods explained in chapter 1 and looks at the deeper mathematical concepts involved. Chapter 4 then covers the fundamental problem of computational logic: the satisfiability problem, which lies at the heart of the entire book. Methods of solving with both logic and IP are given and their connections are described. Applications in diverse fields are discussed, and Williams shows how IP models can be expressed as satisfiability problems and solved as such. 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
Practical challenges of requirements prioritization based on risk estimation
Authors: Andrea Herrmann, Barbara Paech
Venue: Empirical Software Engineering (2009)

Requirements prioritization and risk estimation are known to be difficult. However, so far, risk-based requirements prioritization has not been investigated empirically and quantitatively. In two quantitative experiments, we explored practical challenges and needs of risk estimations in general and of our method MOQARE specifically. In the first experiment, ten students made individual estimations. In the second one, twenty-four students estimated risks in seven moderated groups. The students prioritized the same requirements with different methods (risk estimation and ranking). During the first experiment, we identified factors which influence the quality of the prioritization. In the second experiment, the results of the risk estimation could be improved by discussing risk estimations in a group of experts, gathering risk statistics, and defining requirements, risks and prioritization criteria more tangibly. This first quantitative study on risk-based requirements prioritization helps to understand the practical challenges of this task and thus can serve as a basis for further research on this topic.