pinecone/core-2020-05-10-deduplication huggingface dataset:
A Neural-Genetic Technique for Coastal  Engineering: Determining Wave-induced  Seabed Liquefaction Depth

In the past decade, computational intelligence (CI) techniques have been widely adopted in various fields such as business, science and engineering, as well as information technology. Specifically, hybrid techniques using artificial neural networks (ANNs) and genetic algorithms (GAs) are becoming an important alternative for solving problems in the field of engineering in comparison to traditional solutions, which ordinarily use complicated mathematical theories. The wave-induced seabed liquefaction problem is one of the most critical issues for analysing and designing marine structures such as caissons, oil platforms and harbours. In the past, various investigations into wave-induced seabed liquefaction have been carried out including numerical models, analytical solutions and some laboratory experiments. However, most previous numerical studies are based on solving complicated partial differential equations. In this study, the proposed neural-genetic model is applied to wave-induced liquefaction, which provides a better prediction of liquefaction potential. The neural-genetic simulation results illustrate the applicability of the hybrid technique for the accurate prediction of wave-induced liquefaction depth, which can also provide coastal engineers with alternative tools to analyse the stability of marine sediments.Griffith Sciences, School of Engineering and Built EnvironmentFull Tex
Sensor Registration for Robotic Applications

Multi-sensor data fusion plays an essential role in most robotic applications. Appropriate registration of information from different sensors is a fundamental requirement in multi-sensor data fusion. Registration requires significant effort particularly when sensor signals do not have direct geometric interpretations, observer dynamics are unknown and occlusions are present. In this paper, we propose Mutual Information (MI) based sensor registration which exploits the effect of a common cause in the observed space on the sensor outputs that does not require any prior knowledge of relative poses of the observers. Simulation results are presented to substantiate the claim that the algorithm is capable of registering the sensors in the presence of substantial observer dynamics
Visually-guided robot navigation: From artificial to natural landmarks

Presentado a la 6th International Conference on Field and Service Robotics (FSR) celebrada en 2007 en Chamonix (Francia).Landmark-based navigation in unknown unstructured environments is far from solved. The bottleneck nowadays seems to be the fast detection of reliable visual references in the image stream as the robot moves. In our research, we have decoupled the navigation issues from this visual bottleneck, by first using artificial landmarks that could be easily detected and identified. Once we had a navigation system working, we developed a strategy to detect and track salient regions along image streams by just performing on-line pixel sampling. This strategy continuously updates the mean and covariances of the salient regions, as well as creates, deletes and merges regions according to the sample flow. Regions detected as salient can be considered as potential landmarks to be used in the navigation task.This work was supported by projects: 'Sistema reconfigurable para la navegación basada en visión de robots caminantes y rodantes en entornos naturales.' (00), 'Perception, action & cognition through learning of object-action complexes.' (4915).This work has been supported by the Spanish\ud
Ministerio de Ciencia y Tecnología and FEDER under the project SIRVENT (DPI2003-05193-C02-01), as well as the European Union under the project\ud
PACO-PLUS (FP6-2004-IST-4-27657).Peer Reviewe
Tradeoffs in SLAM with sparse information filters

Designing filters exploiting the sparseness of the information matrix for efficiently solving the simultaneous localization and mapping (SLAM) problem has attracted significant attention during the recent past. The main contribution of this paper is a review of the various sparse information filters proposed in the literature to date, in particular, the compromises used to achieve sparseness. Two of the most recent algorithms that the authors have implemented, Exactly Sparse Extended Information Filter (ESEIF) by Walter et al. [5] and the D-SLAM by Wang et al. [6] are discussed and analyzed in detail. It is proposed that this analysis can stimulate developing a framework suitable for evaluating the relative merits of SLAM algorithms
Revisiting VLT/UVES constraints on a varying fine-structure constant

Current analyses of VLT/UVES quasar spectra disagree with the Keck/HIRES evidence for a varying fine-structure constant, alpha. To investigate this we introduce a simple method for calculating the minimum possible uncertainty on Delta(alpha)/alpha for a given quasar absorber. For many absorbers in Chand et al. (2004) and for the single-absorber constraint of Levshakov et al. (2006) the quoted uncertainties are smaller than the minimum allowed by the UVES data. Failure of this basic consistency test prevents reliable comparison of the UVES and HIRES results
Hydrodynamical model atmospheres and 3D spectral synthesis

We discuss three issues in the context of three-dimensional (3D)
hydrodynamical model atmospheres for late-type stars, related to spectral line
shifts, radiative transfer in metal-poor 3D models, and the solar oxygen
abundance. We include a brief overview about the model construction, taking the
radiation-hydrodynamics code CO5BOLD (COnservative COde for the COmputation of
COmpressible COnvection in a BOx of L Dimensions with L=2,3) and the related
spectral synthesis package Linfor3D as examples.Comment: 6 pages, 2 figures, to appear in the Proceedings of the
  ESO/Lisbon/Aveiro Workshop "Precision Spectroscopy in Astrophysics", eds. L.
  Pasquini, M. Romaniello, N.C. Santos, and A. Correi
Planets around active stars

We present the results of radial velocity measurements of two samples of
active stars. The first sample contains field G and K giants across the Red
Giant Branch, whereas the second sample consists of nearby young stars (d < 150
pc) with ages between 10 - 300 Myrs. The radial velocity monitoring program has
been carried out with FEROS at 1.52 m ESO telescope (1999 - 2002) and continued
since 2003 at 2.2 m MPG/ESO telescope. We observed stellar radial velocity
variations which originate either from the stellar activity or the presence of
stellar/substellar companions. By means of a bisector technique we are able to
distinguish the sources of the radial velocity variation. Among them we found
few candidates of planetary companions, both of young stars and G-K giants
sample.Comment: 4 pages, 5 figures, to appear in the Proceedings of the ESO Workshop
  "Precision Spectroscopy in Astrophysics", eds. L. Pasquini, M. Romaniello,
  N.C. Santos, A. Correi
Complete determination of the orbital parameters of a system with N+1
  bodies using a simple Fourier analysis of the data

Here we show how to determine the orbital parameters of a system composed of
a star and N companions (that can be planets, brown-dwarfs or other stars),
using a simple Fourier analysis of the radial velocity data of the star. This
method supposes that all objects in the system follow keplerian orbits around
the star and gives better results for a large number of observational points.
The orbital parameters may present some errors, but they are an excellent
starting point for the traditional minimization methods such as the
Levenberg-Marquardt algorithms.Comment: 4 page
Physical parameters of evolved stars in clusters and in the field from
  line-depth ratios

We present a high-resolution spectroscopic analysis of two samples of evolved
stars selected in the field and in the intermediate-age open cluster IC 4651,
for which detailed measurements of chemical composition were made in the last
few years. Applying the Gray's method based on ratios of line depths, we
determine the effective temperature and compare our results with previous ones
obtained by means of the curves of growth of iron lines. The knowledge of the
temperature enables us to estimate other fundamental stellar parameters, such
as color excess, age, and mass.Comment: 4 pages, 1 figure, to appear in the Proceedings of the ESO Workshop
  "Precision Spectroscopy in Astrophysics", eds. L. Pasquini, M. Romaniello,
  N.C. Santos, A. Correi
On the combination of constraint programming and stochastic search: the Sudoku case

Sudoku is a notorious logic-based puzzle that is popular with puzzle enthusiasts the world over. From a computational perspective, Sudoku is also a problem that belongs to the set of NP-complete problems, implying that we cannot hope to find a polynomially bounded algorithm for solving the problem in general. Considering this feature, in this paper we demonstrate how a metaheuristic-based method for solving Sudoku puzzles (which was reported by the same author in an earlier paper), can actually be significantly improved if it is coupled with Constraint Programming techniques. Our results, which have been gained through a large amount of empirical work, suggest that this combination of techniques results in a hybrid algorithm that is significantly more powerful than either of its constituent parts
Analysis of time series data with predictive clustering trees

Predictive clustering is a general framework that unifies clustering and prediction. This paper investigates how to apply this framework to cluster time series data. The resulting system, Clus-TS, constructs predictive clustering trees (PCTs) that partition a given set of time series into homogeneous clusters. In addition, PCTs provide a symbolic description of the clusters. We evaluate Clus-TS on time series data from microarray experiments. Each data set records the change over time in the expression level of yeast genes as a response to a change in environmental conditions. Our evaluation shows that Clus-TS is able to cluster genes with similar responses, and to predict the time series based on the description of a gene. Clus-TS is part of a larger project where the goal is to investigate how global models can be combined with inductive databases.status: publishe
Integrating decision tree learning into inductive databases

In inductive databases, there is no conceptual difference between data and the models describing the data: both can be stored and queried using some query language. The approach that adheres most strictly to this philosophy is probably the one proposed by Calders et al. (2006): in this approach, models are stored in relational tables and queried using standard SQL. The approach has been described in detail for association rule discovery. In this work, we study how decision tree induction can be integrated in this approach. We propose a representation format for decision trees similar to the format proposed earlier for association rules, and queryable using standard SQL; and we present a prototype system in which part of the needed functionality is implemented. In particular, we have developed an exhaustive tree learning algorithm able to answer a wide range of constrained queries.status: publishe
Beam search induction and similarity constraints for predictive clustering trees

Much research on inductive databases (IDBs) focuses on local models, such as item sets and association rules. In this work, we investigate how IDBs can support global models, such as decision trees. Our focus is on predictive clustering trees (PCTs). PCTs generalize decision trees and can be used for prediction and clustering, two of the most common data mining tasks. Regular PCT induction builds PCTs top-down, using a greedy algorithm, similar to that of C4.5. We propose a new induction algorithm for PCTs based on beam search. This has three advantages over the regular method: (a) it returns a set of PCTs satisfying the user constraints instead of just one PCT; (b) it better allows for pushing of user constraints into the induction algorithm; and (c) it is less susceptible to myopia. In addition, we propose similarity constraints for PCTs, which improve the diversity of the resulting PCT set.status: publishe
Enforcing P3P policies using a digital rights management system

The protection of privacy has gained considerable attention recently. In response to this, new privacy protection systems are being introduced. SITDRM is one such system that protects private data through the enforcement of licenses provided by consumers. Prior to supplying data, data owners are expected to construct a detailed license for the potential data users. A license specifies whom, under what conditions, may have what type of access to the protected data.\ud
The specification of a license by a data owner binds the enterprise data handling to the consumer’s privacy preferences. However, licenses are very detailed, may reveal the internal structure of the enterprise and need to be kept synchronous with the enterprise privacy policy. To deal with this, we employ the Platform for Privacy Preferences Language (P3P) to communicate enterprise privacy policies to consumers and enable them to easily construct data licenses. A P3P policy is more abstract than a license, allows data owners to specify the purposes for which data are being collected and directly reflects the privacy policy of an enterprise
Integrating inductive definitions in SAT

We investigate techniques for supporting inductive definitions (IDs) in SAT, and report on an implementation, called MidL, of the resulting solver. This solver was first introduced in [Marien et al. 2006], as a part of a declarative problem solving framework.  We go about our investigation by proposing a new formulation of the semantics of IDs as presented in [Denecker 2000]. This new formulation suggests a way to perform the computational task involved, resulting in an algorithm supporting IDs. We show in detail how to integrate our algorithm with traditional SAT solving techniques. We also point out the similarities with another algorithm that was recently developed for ASP [Anger et al. 2006]. Indeed, our formulation reveals a very tight relation with stable model semantics.  We conclude by an experimental validation of our approach using MidL.status: publishe
A fine-grained XML structural comparison approach

As the Web continues to grow and evolve, more and more information is being placed in structurally rich documents, XML documents in particular, so as to improve the efficiency of similarity clustering, information retrieval and data management applications. Various algorithms for comparing hierarchically structured data, e.g., XML documents, have been proposed in the literature. Most of them make use of techniques for finding the edit distance between tree structures, XML documents being modeled as ordered labeled trees. Nevertheless, a thorough investigation of current approaches led us to identify several structural similarity aspects, i.e. sub-tree related similarities, which are not sufficiently addressed while comparing XML documents. In this paper, we provide an improved comparison method to deal with fine-grained sub-trees and leaf node repetitions, without increasing overall complexity with respect to current XML comparison methods. Our approach consists of two main algorithms for discovering the structural commonality between sub-trees and computing tree-based edit operations costs. A prototype has been developed to evaluate the optimality and performance of our method. Experimental results, on both real and synthetic XML data, demonstrate better performance with respect to alternative XML comparison methods.N/
A Simplification of a Real-Time Verification Problem

We revisit the problem of real-time verification with dense dynamics using
timeout and calendar based models and simplify this to a finite state
verification problem. To overcome the complexity of verification of real-time
systems with dense dynamics, Dutertre and Sorea, proposed timeout and calender
based transition systems to model the behavior of real-time systems and
verified safety properties using k-induction in association with bounded model
checking. In this work, we introduce a specification formalism for these models
in terms of Timeout Transition Diagrams and capture their behavior in terms of
semantics of Timed Transition Systems. Further, we discuss a technique, which
reduces the problem of verification of qualitative temporal properties on
infinite state space of (a large fragment of) these timeout and calender based
transition systems into that on clockless finite state models through a
two-step process comprising of digitization and canonical finitary reduction.
This technique enables us to verify safety invariants for real-time systems
using finite state model-checking avoiding the complexity of infinite state
(bounded) model checking and scale up models without applying techniques from
induction based proof methodology. Moreover, we can verify liveness properties
for real-time systems, which is not possible by using induction with infinite
state model checkers. We present examples of Fischer's Protocol, Train-Gate
Controller, and TTA start-up algorithm to illustrate how such an approach can
be efficiently used for verifying safety, liveness, and timeliness properties
specified in LTL using finite state model checkers like SAL-smc and Spin. We
also demonstrate how advanced modeling concepts like inter-process scheduling,
priorities, interrupts, urgent and committed location can be specified as
extensions of the proposed specification formalism.Comment: 32 Pages, 6 Figures. A preliminary version of this draft appeared in
  the proceedings of ATVA 200
Towards Pose-Invariant 2D Face Classification for Surveillance

A key problem for "face in the crowd" recognition from existing surveillance cameras in public spaces (such as mass transit centres) is the issue of pose mismatches between probe and gallery faces. In addition to accuracy, scalability is also important, necessarily limiting the complexity of face classification algorithms. In this paper we evaluate recent approaches to the recognition of faces at relatively large pose angles from a gallery of frontal images and propose novel adaptations as well as modifications. Specifically, we compare and contrast the accuracy, robustness and speed of an Active Appearance Model (AAM) based method (where realistic frontal faces are synthesized from non-frontal probe faces) against bag-of-features methods (which are local feature approaches based on block Discrete Cosine Transforms and Gaussian Mixture Models). We show a novel approach where the AAM based technique is sped up by directly obtaining pose-robust features, allowing the omission of the computationally expensive and artefact producing image synthesis step. Additionally, we adapt a histogram-based bag-of-features technique to face classification and contrast its properties to a previously proposed direct bag-of-features method. We also show that the two bag-of-features approaches can be considerably sped up, without a loss in classification accuracy, via an approximation of the exponential function. Experiments on the FERET and PIE databases suggest that the bag-of-features techniques generally attain better performance, with significantly lower computational loads. The histogram-based bag-of-features technique is capable of achieving an average recognition accuracy of 89% for pose angles of around 25 degrees
Logic–Based Detection of Conflicts in APPEL Policies

This paper was presented at the International Symposium on Fundamentals of Software Engineering, International Symposium, FSEN 2007, Tehran, Iran, April 17-19, 2007 and published as Lecture Notes on Computer Science, 2007, 4767, pp. 257-271.APPEL is a general language for expressing policies in a variety of application domains with a clear separation between the core language and its specialisation for concrete domains. Policies can conflict, thus leading to undesired behaviour. We present a novel formal semantics for the APPEL language based on ΔDSTL(x) (so far APPEL only had an informal semantics). ΔDSTL(x) is an extension of temporal logic to deal with global applications: it includes modalities to localize properties to system components, an operator to deal with events, and temporal modalities à la Unity. A further contribution of the paper is the development of techniques based on the semantics to reason about conflicts.Peer reviewedPost prin
Formal testing of systems presenting soft and hard deadlines

We present a formal framework to specify and test systems presenting both soft and hard deadlines. While hard deadlines must be always met on time, soft deadlines can be sometimes met in a different time, usually higher, from the specified one. It is this characteristic (to formally define sometimes) what produces several reasonable alternatives to define appropriate implementation relations, that is, relations to decide wether an implementation is correct with respect to a specification. In addition to introduce these relations, we define a testing framework to test implementations
Regulating Data Exchange in Service Oriented Applications

We define a type system for COWS, a formalism for specifying and combining services, while modelling their dynamic behaviour. Our types permit to express policies constraining data exchanges in terms of sets of service partner names attachable to each single datum. Service programmers explicitly write only the annotations necessary to specify the wanted policies for communicable data, while a type inference system (statically) derives the minimal additional annotations that ensure consistency of services initial configuration. Then, the language dynamic semantics only performs very simple checks to authorize or block communication. We prove that the type system and the operational semantics are sound. As a consequence, we have the following data protection property: services always comply with the policies regulating the exchange of data among interacting services. We illustrate our approach through a simplified but realistic scenario for a service-based electronic marketplace
Formal specification of multi-agent systems by using EUSMs

The behavior of e-commerce agents can be defined at different levels of abstraction. A formalism allowing to define them in terms of their economic activities, Utility State Machines, has been proposed. Due to its high level of abstraction, this formalism focuses on describing the economic goals rather on how they are achieved. Though this approach is suitable to specify the objectives of e-commerce agents, as well as to construct formal analysis methodologies, this framework is not suitable to define the strategic behavior of agents. In this paper we develop a new formalism to explicitly define the strategic behavior of agents in a modular way. In particular, we reinterpret the role of utility functions, already used in USMs in a more restrictive manner, so that they define strategic preferences and activities of agents. We apply the formalism to define the agents in a benchmark e-commerce agent environment, the Supply Chain Management Game. Since the strategic behavior of agents is located in a specific part of the formalism, different strategies can be easily considered, which enhances the reusability of the proposed specification
Tagged Volume Rendering of the Heart

We present a novel system for 3-D visualisation of the heart and coronary arteries. Binary tags (generated offline) are combined with value-gradient transfer functions (specified online) allowing for interactive visualisation, while relaxing the offline segmentation criteria. The arteries are roughly segmented using a Hessian-based line filter and the pericardial cavity using a Fast Marching active contour. A comparison of different contour initialisations reveals that simple geometric shapes (such as spheres or extruded polygons) produce suitable results