WWW Programming using computational logic systems (and the PiLLoW/Ciao library)

We discuss from a practical point of view a number of issues involved in writing Internet and WWW applications using LP/CLP systems. We describe Pd_l_oW, a public-domain Internet and WWW programming library for LP/CLP systems which we argüe significantly simplifies the process of writing such applications. Pd_l_oW provides facilities for generating HTML structured documents, producing HTML forms, writing form handlers, accessing and parsing WWW documents, and accessing code posted at HTTP addresses. We also describe the architecture of some application classes, using a high-level model of client-server interaction, active modules. We then propose an architecture for automatic LP/CLP code downloading for local execution, using generic browsers. Finally, we also provide an overview of related work on the topic. The PiLLoW library has been developed in the context of the &- Prolog and CIAO systems, but it has been adapted to a number of popular LP/CLP systems, supporting most of its functionality.

Latest developments in data analysis tools for disruption prediction and for the exploration of multimachine operational spaces.

In the last years significant efforts have been devoted to the development of advanced data analysis tools to both predict the occurrence of disruptions and to investigate the operational spaces of devices, with the long term goal of advancing the understanding of the physics of these events and to prepare for ITER. On JET the latest generation of the disruption predictor called APODIS has been deployed in the real time network during the last campaigns with the new metallic wall. Even if it was trained only with discharges with the carbon wall, it has reached very good performance, with both missed alarms and false alarms in the order of a few percent (and strategies to improve the performance have already been identified). Since for the optimisation of the mitigation measures, predicting also the type of disruption is considered to be also very important, a new clustering method, based on the geodesic distance on a probabilistic manifold, has been developed. This technique allows automatic classification of an incoming disruption with a success rate of better than 85%. Various other manifold learning tools, particularly Principal Component Analysis and Self Organised Maps, are also producing very interesting results in the comparative analysis of JET and ASDEX Upgrade (AUG) operational spaces, on the route to developing predictors capable of extrapolating from one device to another.

Vanadium-Doped In and Sn Sulphides: Photocatalysts able to use the whole visible light spectrum

Using photocatalysis for energy applications depends, more than for environmental purposes or selective chemical synthesis, on converting as much of the solar spectrum as possible; the best photocatalyst, titania, is far from this. Many efforts are pursued to use better that spectrum in photocatalysis, by doping titania or using other materials (mainly oxides, nitrides and sulphides) to obtain a lower bandgap, even if this means decreasing the chemical potential of the electron-hole pairs. Here we introduce an alternative scheme, using an idea recently proposed for photovoltaics: the intermediate band (IB) materials. It consists in introducing in the gap of a semiconductor an intermediate level which, acting like a stepstone, allows an electron jumping from the valence band to the conduction band in two steps, each one absorbing one sub-bandgap photon. For this the IB must be partially filled, to allow both sub-bandgap transitions to proceed at comparable rates; must be made of delocalized states to minimize nonradiative recombination; and should not communicate electronically with the outer world. For photovoltaic use the optimum efficiency so achievable, over 1.5 times that given by a normal semiconductor, is obtained with an overall bandgap around 2.0 eV (which would be near-optimal also for water phtosplitting). Note that this scheme differs from the doping principle usually considered in photocatalysis, which just tries to decrease the bandgap; its aim is to keep the full bandgap chemical potential but using also lower energy photons. In the past we have proposed several IB materials based on extensively doping known semiconductors with light transition metals, checking first of all with quantum calculations that the desired IB structure results. Subsequently we have synthesized in powder form two of them: the thiospinel In2S3 and the layered compound SnS2 (having bandgaps of 2.0 and 2.2 eV respectively) where the octahedral cation is substituted at a â?10% level with vanadium, and we have verified that this substitution introduces in the absorption spectrum the sub-bandgap features predicted by the calculations. With these materials we have verified, using a simple reaction (formic acid oxidation), that the photocatalytic spectral response is indeed extended to longer wavelengths, being able to use even 700 nm photons, without largely degrading the response for above-bandgap photons (i.e. strong recombination is not induced) [3b, 4]. These materials are thus promising for efficient photoevolution of hydrogen from water; work on this is being pursued, the results of which will be presented.

Quasi chaotic digital behaviour in an optically processing

Digital chaotic behavior in an optically processing element is reported. It is obtained as the result of processing two fixed train of bits. The process is performed with an Optically Programmable Logic Gate. Possible outputs for some specific conditions of the circuit are given. These outputs have some fractal characteristics, when input variations are considered. Digital chaotic behavior is obtained by using a feedback configuration. A random-like bit generator is presented.

Analysis of digital chaotic optical signals

The main objective of this paper is to present some tools to analyze a digital chaotic signal. We have proposed some of them previously, as a new type of phase diagrams with binary signals converted to hexadecimal. Moreover, the main emphasis will be given in this paper to an analysis of the chaotic signal based on the Lempel and Ziv method. This technique has been employed partly by us to a very short stream of data. In this paper we will extend this method to long trains of data (larger than 2000 bit units). The main characteristics of the chaotic signal are obtained with this method being possible to present numerical values to indicate the properties of the chaos.

A new method to analyse the perception of size

In living bodies, the correct perceptual representation of size constancy requires that an object's size appear the same when it changes its location with respect to the observer. At the same time, it is necessary that objects at different locations appear to be the same size if they are. In order to do that, the perceptual system must recover from the stimuli impinging on the individual, from the light falling on the retina, a representation of the relative sizes of objects in the environment. Moreover, at the same time, image perception is related to another type of phenomena. It corresponds to the well known perceptual illusions. To analyze this facts, we propose a system based on a particular arrays of receptive points composed by optical fibers and dummy fibers. The structure is based on the first layers of the mammalians primary visual cortex. At that part of the brain, the neurons located at certain columns, respond to particular directions. This orientation changes in a systematic way as one moves across the cortical surface. In our case, the signals from the above-mentioned array are analyzed and information concerning orientation and size of a particular line is obtained. With this system, the Muelle-Lyer illusion has been studied and some rules to interpret why equal length objects give rise to different interpretations are presented.

Strange attractor in optical logic cells

Optical logic cells, employed in several tasks as optical computing or optically controlled switches for photonic switching, offer a very particular behavior when the working conditions are slightly modified. One of the more striking changes occurs when some delayed feedback is applied between one of the possible output gates and a control input. Some of these new phenomena have been studied by us and reported in previous papers. A chaotic behavior is one of the more characteristic results and its possible applications range from communications to cryptography. But the main problem related with this behavior is the binary character of the resulting signal. Most of the nowadays-employed techniques to analyze chaotic signals concern to analogue signals where algebraic equations are possible to obtain. There are no specific tools to study digital chaotic signals. Some methods have been proposed. One of the more used is equivalent to the phase diagram in analogue chaos. The binary signal is converted to hexadecimal and then analyzed. We represented the fractal characteristics of the signal. It has the characteristics of a strange attractor and gives more information than the obtained from previous methods. A phase diagram, as the one obtained by previous techniques, may fully cover its surface with the trajectories and almost no information may be obtained from it. Now, this new method offers the evolution around just a certain area being this lines the strange attractor.

Time evolution of frequency components In a chaotic digital signal

The type of signals obtained has conditioned chaos analysis tools. Almost in every case, they have analogue characteristics. But in certain cases, a chaotic digital signal is obtained and theses signals need a different approach than conventional analogue ones. The main objective of this paper will be to present some possible approaches to the study of this signals and how information about their characteristics may be obtained in the more straightforward possible way. We have obtained digital chaotic signals from an Optical Logic Cell with some feedback between output and one of the possible control gates. This chaos has been reported in several papers and its characteristics have been employed as a possible method to secure communications and as a way to encryption. In both cases, the influence of some perturbation in the transmission medium gave problems both for the synchronization of chaotic generators at emitter and receiver and for the recovering of information data. A proposed way to analyze the presence of some perturbation is to study the noise contents of transmitted signal and to implement a way to eliminate it. In our present case, the digital signal will be converted to a multilevel one by grouping bits in packets of 8 bits and applying conventional methods of time-frequency analysis to them. The results give information about the change in signals characteristics and hence some information about the noise or perturbations present. Equivalent representations to the phase and to the Feigenbaum diagrams for digital signals are employed in this case.

Software industry experiments: a systematic literature review

There is no specialized survey of experiments conducted in the software industry. Goal: Identify the major features of software industry experiments, such as time distribution, independent and dependent variables, subject types, design types and challenges. Method: Systematic literature review, taking the form of a scoping study. Results: We have identified 10 experiments and five quasi-experiments up to July 2012. Most were run as of 2003. The main features of these studies are that they test technologies related to quality and management and analyse outcomes related to effectiveness and effort. Most experiments have a factorial design. The major challenges faced by experimenters are to minimize the cost of running the experiment for the company and to schedule the experiment so as not to interfere with production processes.

Building lean thinking in a telecom software development organization: strengths and challenges.

The potential shown by Lean in different domains has aroused interest in the software industry. However, it remains unclear how Lean can be effectively applied in a domain such as software development that is fundamentally different from manufacturing. This study explores how Lean principles are implemented in software development companies and the challenges that arise when applying Lean Software Development. For that, a case study was conducted at Ericsson R&D Finland, which successfully adopted Scrum in 2009 and subsequently started a comprehensible transition to Lean in 2010. Focus groups were conducted with company representatives to help devise a questionnaire supporting the creation of a Lean mindset in the company (Team Amplifier). Afterwards, the questionnaire was used in 16 teams based in Finland, Hungary and China to evaluate the status of the transformation. By using Lean thinking, Ericsson R&D Finland has made important improvements to the quality of its products, customer satisfaction and transparency within the organization. Moreover, build times have been reduced over ten times and the number of commits per day has increased roughly five times.The study makes two main contributions to research. First, the main factors that have enabled Ericsson R&D?s achievements are analysed. Elements such as ?network of product owners?, ?continuous integration?, ?work in progress limits? and ?communities of practice? have been identified as being of fundamental importance. Second, three categories of challenges in using Lean Software Development were identified: ?achieving flow?, ?transparency? and ?creating a learning culture?

BiGlobal and point vortex methods for the instability analysis of wakes

To better understand destruction mechanisms of wake-vortices behind aircraft, the point vortex method for stability (inviscid) used by Crow is here compared with viscous modal global stability analysis of the linearized Navier-Stokes equations acting on a two-dimensional basic flow, i.e. BiGlobal stability analysis. The fact that the BiGlobal method is viscous, and uses a flnite área vortex model, gives rise to results somewhat different from the point vortex model. It adds more parameters to the problem, but is more realistic.

Spatial linear global instability analysis of the HIFiRE-5 elliptic cone model flow

The linear instability of the three-dimensional boundary-layer over the HIFiRE-5 flight test geometry, i.e. a rounded-tip 2:1 elliptic cone, at Mach 7, has been analyzed through spatial BiGlobal analysis, in a effort to understand transition and accurately predict local heat loads on next-generation ight vehicles. The results at an intermediate axial section of the cone, Re x = 8x10 5, show three different families of spatially amplied linear global modes, the attachment-line and cross- ow modes known from earlier analyses, and a new global mode, peaking in the vicinity of the minor axis of the cone, termed \center-line mode". We discover that a sequence of symmetric and anti-symmetric centerline modes exist and, for the basic ow at hand, are maximally amplied around F* = 130kHz. The wavenumbers and spatial distribution of amplitude functions of the centerline modes are documented

An asymptotic solution for the main problem

In this paper, an analytical solution of the main problem, a satellite only perturbed by the J2 harmonic, is derived with the aid of perturbation theory and by using DROMO variables. The solution, which is valid for circular and elliptic orbits with generic eccentricity and inclination, describes the instantaneous time variation of all orbital elements, that is, the actual values of the osculating elements

A new regularization method for fast and accurate propagation of roto-translationally coupled asteroids

There is a well-distinguished group of asteroids for which the roto-translational cou-pling is known to have a non-negligible e�ect in the long-term. The study of such asteroids suggests the use of specialized propagation techniques, where perturbation methods make their best. The techniques from which the special regularization method DROMO is derived, have now been extended to the attitude dynamics, with equally remarkable results in terms of speed and accuracy, thus making the combination of these algorithms specially. well-suited to deal with the propagation of bodies with strong attitude coupling.

Los productos forestales no maderables como complemento económico en zonas forestales de países en desarrollo. Caso de El Merendón, en San Pedro Sula. Honduras. CA.

Se analizan las posibilidades que tiene el cultivo de mariposas y la utilización de las plantas en la alimentación, sanidad y otros usos en el medio rural de Honduras, como complemento para su desarrollo.