Scipedia: Documents published in 2009

Static timing analysis for hard real-time systems

Scipedia content — Wed, 14 Oct 2020 15:15:56 +0200

Hard real-time systems have to satisfy strict timing constraints. To prove that these constraints are met, timing analyses aim to derive safe upper bounds on tasks execution times. Processor components such as caches, out-of-order pipelines, and speculation cause a large variation of the execution time of instructions, which may induce a large variability of a tasks execution time. The architectural platform also determines the precision and the complexity of timing analysis.\r \r This paper provides an overview of our timing-analysis technique and in particular the methodological aspects of interest to the verification community.

Document type: Part of book or chapter of book

The Elite Brain Drain

Scipedia content — Wed, 14 Oct 2020 15:08:39 +0200

We collect data on the movement and productivity of elite scientists. Their mobility is remarkable: nearly half of the world's most-cited physicists work outside their country of birth. We show they migrate systematically towards nations with large R & D spending. Our study cannot adjudicate on whether migration improves scientists' productivity, but we find that movers and stayers have identical h-index citations scores. Immigrants in the UK and US now win Nobel Prizes proportionately less often than earlier. US residents' h-indexes are relatively high. We describe a framework where a key role is played by low mobility costs in the modern world. Copyright © The Author(s). Journal compilation © Royal Economic Society 2009.

Document type: Book

Alleine wohnen empirische befunde zu einer weit verbreiteten lebensform

Scipedia content — Wed, 14 Oct 2020 15:06:57 +0200

Die im Zuge des sozialen Wandels zu beobachtende Ausdifferenzierung von Lebens- und Wohnformen wird verbreitet als Ausdruck von Individualisierung und erweiterten Wahlmöglichkeiten gedeutet. Laut diesem Denkzusammenhang ist die Zunahme von Einpersonenhaushalten vor allem den großstädtischen Singles zuzuschreiben. Der Beitrag liefert - basierend auf Auswertungen der laufenden Bevölkerungsumfrage des BBSR - empirische Befunde zur Wohn- und Lebenssituation allein wohnender Frauen und Männer in Deutschland. Als theoretische Orientierung werden vier Charakteristika heutigen Wohnens von Hartmut Häußermann und Walter Siebel zugrunde gelegt.

Document type: Part of book or chapter of book

Air traffic control a local approach to the trajectory segmentation issue

Scipedia content — Wed, 14 Oct 2020 15:06:44 +0200

Proceedings of: 23rd International Conference on Industrial, Engineering & Other Applications of Applied Intelligent Systems (IEA-AIE 2010) Córdoba-Spain, June 04-06, 2010 This paper presents a new approach for trajectory segmentation in the area of Air Traffic Control, as a basic tool for offline validation with recorded opportunity traffic data. Our approach uses local information to classify each measurement individually, constructing the final segments over these classified samples as the final solution of the process. This local classification is based on a domain transformation using motion models to identify the deviations at a local scale, as an alternative to other global approaches based on combinatorial analysis over the trajectory segmentation domain. This work was supported in part by Projects CICYT TIN2008-06742-C02-02/TSI, CICYT TEC2008-06732-C02-02/TEC, CAM CONTEXTS (S2009/TIC-1485) and DPS2008-07029-C02-02. Publicado

Document type: Part of book or chapter of book

Verkennende ecologische gebiedsvisie voor het leopoldkanaal en omgeving

Scipedia content — Wed, 14 Oct 2020 15:02:12 +0200

Document type: Book

Let it flow building mashups with data processing pipelines

Scipedia content — Wed, 14 Oct 2020 14:41:20 +0200

Mashups are a new kind of interactive Web application, built out of the composition of two or more existing Web service APIs and data sources. Whereas "pure" mashups are built relying entirely on the Web browser as a platform for integration at the presentation layer, this approach is not always feasible and part of the mashup integration logic must be deployed on the Web server instead. In the case study presented in this paper, we explore a novel approach to build mashups out of heterogeneous sources of streaming data. In particular, we introduce a layered mashup architecture, with a clear separation between the mashup user interface and the mashup integration logic run by a mashup engine. To do so, we show how to build a mashup application that displays in real time the location of visitors connecting to a Website. The integration logic feeding a map widget by processing the Web site logs is developed using a data flow model that connects a set of reusable and heterogeneous components into a data processing pipeline. We conduct a brief performance evaluation of the mashup showing that the pipeline introduces minimal delay and discuss several extensions of the mashup.

Document type: Part of book or chapter of book

Solar Energy

Scipedia content — Wed, 14 Oct 2020 14:33:54 +0200

This thesis is about Photovoltaic (PV) cells and its stresses in various directions by calculating the power generated using solar cells under different conditions to improve its efficiency. Our research studies found that using multi-junction cells with larger substrates can increase the efficiency to some extent which in practice is limited to 43 percent. The experiment was conducted using ten solar cells each with an area of 20.9?cm? ^2, where each cell gives 0.5 V and 0.4 A and a 1.25 ? resistor was used. The cells were connected in series. Once, the PV cells were fixed horizontally and the other time tested in tilted position under same outdoor condition. The purpose of testing PV cells was to investigate the efficiency under above mentioned conditions. The data collected from the readings was used in calculation, and we have obtained from the calculations that horizontally fixed cells gave 4.8 percent efficiency whereas tilted cells gave 6.6 percent efficiency. Hence, the ratio showed that fixed cells produced 37.5 percent more power compared to horizontally fixed cells. Our other experiment consisted of testing PV cells under different temperature conditions that was done using a freezer and an oven for temperature variation and a tungsten bulb was used as a light source. The purpose of performing this experiment was to investigate how the efficiency of PV cells is affected under extreme conditions. Part of our thesis was also including studies and analysis of produced energy by the solar panel installed on the roof of BTH building in Karlskrona, Sweden. The data consisted of energy produced from February up to August 2014. The investigation also included finding the highest produced energy during these months. We have found that the highest energy was generated on the 1st of July which was 12.86 kWh. Furthermore, we went deep into investigation of the 1st of July to know exactly which hour of that day the highest energy was produced. The data showed that the highest produced energy was at 12:19 and 13:19 which was 2.03 kWh. Ramzi: +46723231353, +966561993488 Zain

Document type: Part of book or chapter of book

Some observations on the air transport of animals

Scipedia content — Wed, 14 Oct 2020 14:23:56 +0200

With the increase in air transport, the transport of animals has grown, too. According to the International Association for Transport Companies, more than 500,000 animals are transported by airlines annually. Problems are caused by inadequate cages, an absence of health certificates, differences in temperature, insufficient oxygen and bad treatment. The European Convention for Protection of Animals during International Transport is divided into two parts: general rules and special rules. The latter include items such as means of transport, the same sort of animals being together and no overcrowding. National rules also exist and may include special rules for animals which are taken into the cabin. The US Federal Aviation Administration (FAA) allows each airline to decide whether or not to allow a person to travel with a pet in the passenger cabin. The rules are similar to the above European Convention of 1968. Keywords: animals; federal aviation administration (FAA); international transpor

Document type: Part of book or chapter of book

Evaluation of Automatically Extracted Landmarks for Future Driver Assistance Systems

Scipedia content — Wed, 14 Oct 2020 14:23:11 +0200

In the future, vehicles will gather more and more spatial information about their environment, using on-board sensors such as cameras and laser scanners. Using this data, e.g. for localization, requires highly accurate maps with a higher level of detail than provided by today's maps. Producing those maps can only be realized economically if the information is obtained fully automatically. It is our goal to investigate the creation of intermediate level maps containing geo-referenced landmarks, which are suitable for the specific purpose of localization. To evaluate this approach, we acquired a dense laser scan of a 22 km scene, using a mobile mapping system. From this scan, we automatically extracted pole-like structures, such as street and traffic lights, which form our pole database. To assess the accuracy, ground truth was obtained for a selected inner-city junction by a terrestrial survey. In order to evaluate the usefulness of this database for localization purposes, we obtained a second scan, using a robotic vehicle equipped with an automotive-grade laser scanner. We extracted poles from this scan as well and employed a local pole matching algorithm to improve the vehicle's position.

Document type: Part of book or chapter of book

Perceptions of risk and control understanding acceptance of advanced driver assistance systems

Scipedia content — Wed, 14 Oct 2020 14:22:30 +0200

With a marked increase in advanced driver assistance systems (ADAS) being designed and deployed for cars, there is a logical emergence of studies that critically examine the influence these have on driver behavior and attitudes towards risk and safety. The research question addressed within this paper asks to what extent the level of perceived criticality or risk on the part of drivers influences their acceptance of advanced assistance.

Document type: Part of book or chapter of book

Jbig for printer pipelines a compression test

Scipedia content — Wed, 14 Oct 2020 14:10:26 +0200

The proposed paper describes a compression test analysis of JBIG standard algorithm. The aim of such work is to proof the effectiveness of this standard for images acquired through scanners and processed into a printer pipeline. The main issue of printer pipelines is the necessity to use a memory buffer to store scanned images for multiple prints. This work demonstrates that for very large scales the buffer can be fixed using medium compression case, using multiple scans in case of uncommon random patterns.

Document type: Part of book or chapter of book

Moving Object Segmentation Using Optical Flow and Depth Information

Scipedia content — Wed, 14 Oct 2020 14:07:09 +0200

This paper discusses the detection of moving objects (being a crucial part of driver assistance systems) using monocular or stereoscopic computer vision. In both cases, object detection is based on motion analysis of individually tracked image points (optical flow), providing a motion metric which corresponds to the likelihood that the tracked point is moving. Based on this metric, points are segmented into objects by employing a globally optimal graph-cut algorithm. Both approaches are comparatively evaluated using real-world vehicle image sequences.

Document type: Part of book or chapter of book

Cause and effect in user interface development

Scipedia content — Wed, 14 Oct 2020 14:03:24 +0200

There is a lack of means of translating work products of elicitation to design and using results of evaluation as feedback to design. This paper lays the foundation of a model of evaluation to be built concurrently with the design activity. The evaluation model describes the implications which work models have on design and records the cause/effect relationship between design and the problem domain. The paper presents two case studies from air traffic control that are meant to motivate the need for such an evaluation model and serve as input to its design.

Document type: Part of book or chapter of book

Lock in effects of road expansion on co2 emissions results from a core periphery model of beijing

Scipedia content — Wed, 14 Oct 2020 13:53:12 +0200

In the urban planning literature, it is frequently explicitly asserted or strongly implied that ongoing urban sprawl and decentralization can lead to development patterns that are unsustainable in the long run. One manifestation of such an outcome is that if extensive road investments occur, urban sprawl and decentralization are advanced and locked-in, making subsequent investments in public transit less effective in reducing vehicle kilometers traveled by car, gasoline use and carbon dioxide emissions. Using a simple core-periphery model of Beijing, the authors numerically assess this effect. The analysis confirms that improving the transit travel time in Beijing?s core would reduce the city?s overall carbon dioxide emissions, whereas the opposite would be the case if peripheral road capacity were expanded. This effect is robust to perturbations in the model?s calibrated parameters. In particular, the effect persists for a wide range of assumptions about how location choice depends on travel time and a wide range of assumptions about other aspects of consumer preferences.

Document type: Book

Computing Differential Invariants of Hybrid Systems as Fixedpoints

Scipedia content — Wed, 14 Oct 2020 13:01:32 +0200

We introduce a fixedpoint algorithm for verifying safety properties of hybrid systems with differential equations whose right-hand sides are polynomials in the state variables. In order to verify nontrivial systems without solving their differential equations and without numerical errors, we use a continuous generalization of induction, for which our algorithm computes the required differential invariants. As a means for combining local differential invariants into global system invariants in a sound way, our fixedpoint algorithm works with a compositional verification logic for hybrid systems. With this compositional approach we exploit locality in system designs. To improve the verification power, we further introduce a saturation procedure that refines the system dynamics successively with differential invariants until safety becomes provable. By complementing our symbolic verification algorithm with a robust version of numerical falsification, we obtain a fast and sound verification procedure. We verify roundabout maneuvers in air traffic management and collision avoidance in train control and car control.

Document type: Part of book or chapter of book

Internationale Kompetenzen in der Berufsbildung: Stand der Wissenschaft und praktische Anforderungen

Scipedia content — Wed, 14 Oct 2020 13:00:18 +0200

In dieser Einleitung wird ein Überblick über den Stand der Wissenschaft sowie die praktischen Anforderungen im Hinblick auf internationale Kompetenzen in der Berufsbildung gegeben: Zunächst werden unter der Perspektive von der Exportorientierung über den Binnenmarkt zur Globalisierung die Bedarfsseiten der internationalen Qualifikationen sowie die Feststellung von internationalen Kompetenzen und ihre Verankerung in den Ausbildungsvorschriften beleuchtet. Danach wird auf den Erwerb internationaler Kompetenzen durch transnationale Mobilität insbesondere in Form von Auslandspraktika eingegangen. Zuletzt werden die Forschung über internationale Berufsbildung sowie die internationale berufliche Handlungskompetenz thematisiert. (DIPF/paul)

Document type: Part of book or chapter of book

Environmental costs account a base for measuring sustainability in transport plans

Scipedia content — Wed, 14 Oct 2020 12:59:51 +0200

Each city need to develop sustainable transport plans according to its future developments. This means identifying the best policy package of transport measures that could produce more sustainable future scenarios: lowest environmental impact, but also better social standards and at minimum cost. To that end, it is necessary to measure the environmental and social costs of each alternative transport mode. This paper proposes a methodology to calculate those costs in different city contexts: city centre and metropolitan suburbs. It provides a measure of the following environmental costs: pollution, noise, green house gasses and land taken. Then the social costs as congestion and accident costs. These two cost categories are calculated for each mean of transport: metro, bus, private car and taxi. The methodology has been applied to Madrid Region through modeling its mobility demand in 2004. The outputs are costs per passenger-km in each mode and Area: city centre and metropolitan ring. Therefore it is possible to assign monetary costs to environmental and social costs of each transport option; for example, car environmental costs are four times higher than buses on average, but it differs a lot from city centre to outskirt areas. Finally, some guidelines can be extracted to develop a more sustainable transport policy for Madrid Region. No data (2010) UEM

Document type: Part of book or chapter of book

Pricing externalities from passenger transportation in mexico city

Scipedia content — Wed, 14 Oct 2020 12:51:03 +0200

The Mexico City Metropolitan Area has been suffering severely from transportation externalities such as accidents, air pollution, and traffic congestion. This study examines pricing instruments to reduce these externalities using an analytical and numerical model. The study shows that the optimal levels of a gasoline tax and a congestion toll on automobiles could generate social benefits, measured in terms of welfare gain, of US$132 and US$109 per capita, respectively, through the reduction of externalities. The largest component of the welfare gains comes from reduced congestion, followed by local air pollution reduction. The optimal toll and tax would, however, double the cost of driving and could be politically sensitive. Still, more than half of those welfare gains could be obtained through a more modest tax or toll, equivalent to $1 per gallon of gasoline. The welfare gains from reforming the pricing of public transportation are small relative to those from reforming the taxation of automobiles. Although the choice among travel modes depends on specific circumstances, in the absence of road travel pricing that accounts for externalities, there will be potential for higher investment in roads relative to mass transit. Given the rapidly increasing demand for transportation infrastructure in Mexico City, careful efforts should be made to include the full social costs of travel in evaluating alternative infrastructure investments.

Document type: Book

A grounded theory approach towards conceptualizing CIS for heterogeneous work communities

Scipedia content — Wed, 14 Oct 2020 12:45:40 +0200

The notion of Common Information Space (CIS) is an area that has been gaining attention in the field of Computer Supported Cooperative Work (CSCW) over the last few years. This paper discusses one aspect of the investigation being undertaken to develop the conceptualization of CIS pertaining to heterogeneous work communities. This is based on empirical study of collaborative decision making involving different work communities in an airport of the air traffic control setting. The theory development is founded on the Grounded Theory approach. We present some of the findings of the ongoing analysis. In particular we discuss how the Grounded Theory methodological process has been adapted to this investigation by presenting illustrations of emergent theory development at the theoretical coding phase of the process.

Document type: Part of book or chapter of book

How to Improve the Capture of Urban Goods Movement Data?

Scipedia content — Wed, 14 Oct 2020 12:44:37 +0200

Paper presented at the Session: Urban goods surveys; The surveys specifically focused on the thorough knowledge of urban freight transport appeared about ten years ago. The local problematic of goods transport at local level was partially taken into account by the city planners and by the researchers: until recent years, the integration of goods transport in the total urban flows models was estimated applying a multiplying factor to car traffic. Delivering goods was not considered like a concern."br /"Because of the quick growth of car traffic in the cities, the main stakes changed too: the fight against traffic congestion, the management of the lack of space (shipment consolidation and storage), the attempts to reduce local environmental impacts and global externalities (energy saving, reduction of greenhouse gas emissions), and economic valuation of city centres (under the pressure of a slowed down economic growth)."br /"All these changes were taking place in a context in which available rooms for manoeuvre were limited by factors such as congestion, concerns about the quality of urban life and budget restriction. It resulted in a growing unease on the freight transport industry and the city authorities, the latter having little or no data, methods and references in order to elaborate a satisfactory policy framework.

Document type: Part of book or chapter of book

Road projects cost benefit analysis scenario analysis of the effect of varying inputs

Scipedia content — Tue, 29 Sep 2020 09:58:50 +0200

Six projects from six countries were selected as the cases for detailed analysis in this study. They are from Argentina, Botswana, India, Kenya, Lao PDR and Paraguay, representing a wide range of geographical distribution. Also, the extent of the effect of economic downturn which these countries experienced ranges a wide variety. In an economic downturn, uncertainties increase with many inputs of road projects Cost Benefit Analysis (CBA), including fuel prices, levels of demand, investment costs and maintenance availability. Also, important parameters of project evaluation such as discount rate and value of time need to be more carefully scrutinized. Therefore, it is very important for the developing countries to have good understanding about the effects of the variability of these inputs/parameters on project viability and the ranking of road investments. It is a role of the developing agencies to conduct a systematic analysis of these effects and disseminate the findings and knowledge obtained. The objective of the study is to obtain insights regarding the effects of varying inputs and parameters on the viability of road projects through case studies using Highway Development and Management Model (HDM-4), thereby to facilitate the formulation and implementation of road projects that increase the welfare of the society under the environment of increased uncertainty in an economic downturn. The results of the study will be summarized in a transport note as a discrete knowledge product and disseminated among various stakeholders including developing agencies staff, government officials and donor communities. To assess the effects of increased uncertainty with inputs of cost benefit analysis on the economic viability of road projects, this study first investigated the range of variability of the inputs for the six selected projects/countries. It was found that the variability ranges differ by country reflecting the degree of decrease in transport demand and relative change in factor prices due to economic downturn.

Document type: Book

Institutional Development and Good Governance in the Highway Sector

Scipedia content — Tue, 29 Sep 2020 09:52:38 +0200

The World Bank financed the Gujarat State Highway Project (GSHP) during 2001-07. The project development objective was to enhance the capacity of the Government of Gujarat (GOG) for effective and efficient planning and management of road infrastructure, while concurrently maximizing existing road infrastructure asset productivity through priority investments and increased maintenance funding. The project not only achieved its objective and targets successfully, but also was implemented with a significant cost reduction (about 23 percent). The GSHP resulted in a reduction in the backlog of major maintenance and an improved network to meet rapidly growing transport demand in the state. The project had the unique distinction of no contract disputes, a rarity among the highway development projects in India. The project also set best practices in developing and managing a very comprehensive asset management system, state of the art quality assurance framework and a very comprehensive training and capacity building program. The annual road sector allocation has grown from USD 30 million in 1995-1996 to an impressive USD 610 million in 2010-11, currently the second largest among all the Indian states. This study attempts to identify the key elements of the Gujarat road sector reforms and explores whether and, if so, how such reforms can be replicated across other Indian states and possibly even in other countries in the region.

Document type: Book

Die Europäisierung der Berufsbildung und ihre Auswirkungen auf die deutsche Trägerlandschaft

Scipedia content — Tue, 29 Sep 2020 09:51:15 +0200

Der Autor stellt zunächst einige allgemeine Überlegungen zum Thema „Mobilität und berufliche Bildung“ sowie zur Europäisierung und Internationalisierung der Berufsbildung an. Dabei nennt er insbesondere den EQF (den Europäischen Qualifikationsrahmen) und das ECVET (das Europäische Credit-System für die Berufsbildung) als Instrumente und Maßnahmen, mehr Transparenz und Vergleichbarkeit, mehr Mobilität und mehr Durchlässigkeit in den und zwischen den Bildungssystemen durchzusetzen. Anschließend geht er zu den Folgerungen über, die sich daraus für Anbieter beruflicher Bildung in Deutschland ergeben. Exemplarisch zeigt er dabei an einigen Aktivitäten der bbw Group auf, was das für den Bereich der beruflichen Bildung konkret bedeuten kann. (DIPF/ ssch)

Document type: Part of book or chapter of book

Contingency Plans for Air Traffic Management

Scipedia content — Tue, 29 Sep 2020 09:41:01 +0200

We present two heuristics based on constraint technology that solve the problem of generating air traffic management contingency plans, which are used in the case of a catastrophic infrastructure failure within EUROCONTROL, the European Organisation for the Safety of Air Navigation. Of the heuristics presented, one is based on constraint-based local search and tabu search, and the other one is a constraint programming and large neighbourhood search hybrid algorithm. The heuristics show that it is feasible to automate the development of contingency plans, which is currently done by human experts; this is desirable for several reasons, for example it would allow the contingency plans to be generated with an increased frequency. The generated plans were evaluated, by EUROCONTROL, to be at least as good as the human-made ones.

Document type: Part of book or chapter of book

Olgierd Cecil Zienkiewicz obituary

María Jesús Samper — Tue, 19 Nov 2019 11:52:37 +0100

Control of the finite element discretization error during the convergence of structural shape optimization algorithms

María Jesús Samper — Tue, 19 Nov 2019 11:44:06 +0100

This work analyzes the influence of the discretization error contained in the Finite Element (FE) analyses of each design configuration proposed by structural shape optimization algorithms over the behaviour of the algorithm. If the FE analyses are not accurate enough, the final solution will neither be optimal nor satisfy the constraints. The need for the use of adaptive FE analysis techniques in shape optimum design will be shown. The paper also proposes the use of the algorithm described in [1] in order to reduce the computational cost associated to the adaptive FE analysis of each geometrical configuration when evolutive optimization algorithms are used.

Guaranteed energy error bounds for the Poisson equation using a flux-free approach: solving the local problems in subdomains

María Jesús Samper — Mon, 28 Oct 2019 15:32:27 +0100

A method to compute guaranteed upper bounds for the energy norm of the exact error in the finite element solution of the Poisson equation is presented. The bounds are guaranteed for any finite element mesh however coarse it may be, not just in the asymptotic regime. The bounds are constructed by employing a subdomain based a posteriori error estimate which yields self-equilibrated residual loads in stars (patches of elements). The proposed approach is an alternative to standard equilibrated residual methods providing sharper bounds. The use of a flux-free error estimator improves the effectivities of the upper bounds for the energy while retaining the certainty of the bounds.

Exact bounds for linear outputs of the advection-diffusion-reaction equation using flux-free error estimates

María Jesús Samper — Mon, 28 Oct 2019 15:28:02 +0100

The paper introduces a methodology to compute strict upper and lower bounds for linear-functional outputs of the exact solutions of the advection-reaction-diffusion equation. The proposed approach is an alternative to the standard residual type estimators (hybrid-flux), circumventing the need of flux-equilibration following a fluxfree error estimation strategy. The presented estimator provides sharper estimates than the ones provided by both the standard hybrid-flux techniques and other flux-free techniques.

Hierarchical X-FEM for n-phase flow (n>2)

María Jesús Samper — Mon, 28 Oct 2019 15:22:46 +0100

The eXtended Finite Element Method (X-FEM) has been successfully used in two-phase flow problems involving a moving interface. In order to simulate problems involving more than two phases, the X-FEM has to be further eXtended. The proposed approach is presented in the case of a quasi-static Stokes n-phase flow and it is based on using an ordered collection of level set functions to describe the location of the phases. A level set hierarchy allows describing triple junctions avoiding overlapping or “voids” between materials. Moreover, an enriched solution accounting for several simultaneous phases inside one element is proposed. The interpolation functions corresponding to the enriched degrees of freedom require redefining the associated ridge function accounting for all the level sets.

The computational implementation of this scheme involves calculating integrals in elements having several materials inside. An adaptive quadrature accounting for the interfaces locations is proposed to accurately compute these integrals.

Examples of the hierarchical X-FEM approach are given for a n-phase Stokes problem in 2 and 3 dimensions.

Strict error bounds for linear solid mechanics problems using a subdomain-based flux-free method

María Jesús Samper — Mon, 28 Oct 2019 15:17:41 +0100

We discuss, in this paper, a flux-free method for the computation of strict upper bounds of the energy norm of the error in a Finite Element (FE) computation. The bounds are strict in the sense that they refer to the difference between the displacement computed on the FE mesh and the exact displacement, solution of the continuous equations, rather than to the difference between the displacements computed on two FE meshes, one coarse and one refined. This method is based on the resolution of a series of local problems on patches of elements and does not require the resolution of a previous problem of flux equilibration, as happens with other methods. The paper concentrates more specifically on linear solid mechanics issues, and on the assessment of the energy norm of the error, seen as a necessary tool for the estimation of the error in arbitrary quantities of interest (linear functional outputs). Applications in both 2D and 3D are presented

A simple strategy to assess the error in the numerical wave number of the finite element solution of the Helmholtz equation

María Jesús Samper — Mon, 28 Oct 2019 15:04:31 +0100

The standard approach for goal oriented error estimation and adaptivity uses an error representation via an adjoint problem, based on the linear functional output representing the quantity of interest. For the assessment of the error in the approximation of the wave number for the Helmholtz problem (also referred to as dispersion or pollution error), this strategy cannot be applied. This is because there is no linear extractor producing the wave number from the solution of the acoustic problem. Moreover, in this context, the error assessment paradigm is reverted in the sense that the exact value of the wave number, κ, is known (it is part of the problem data) and the effort produced in the error assessment technique aims at obtaining the numerical wave number, κH, as a postprocess of the numerical solution, uH. The strategy introduced in this paper is based on the ideas used in the a priori analysis. A modified equation corresponding to a modified wave number κm is introduced. Then, the value of κm such that the modified problem better accommodates the numerical solution uH is taken as the estimate of the numerical wave number κH. Thus, both global and local versions of the error estimator are proposed. The obtained estimates of the dispersion error match the a priori predicted dispersion error and, in academical examples, the actual values of the error in the wave number.

The fixed‐mesh ALE approach applied to solid mechanics and fluid–structure interaction problems

María Jesús Samper — Thu, 05 Sep 2019 09:41:24 +0200

In this paper we propose a method to solve Solid Mechanics and fluid–structure interaction problems using always a fixed background mesh for the spatial discretization. The main feature of the method is that it properly accounts for the advection of information as the domain boundary evolves. To achieve this, we use an Arbitrary Lagrangian–Eulerian (ALE) framework, the distinctive characteristic being that at each time step results are projected onto a fixed, background mesh. For solid mechanics problems subject to large strains, the fixed‐mesh (FM)‐ALE method avoids the element stretching found in fully Lagrangian approaches. For FSI problems, FM‐ALE allows for the use of a single background mesh to solve both the fluid and the structure.

Approximate imposition of boundary conditions in immersed boundary methods

María Jesús Samper — Tue, 03 Sep 2019 15:29:19 +0200

We analyze several possibilities to prescribe boundary conditions in the context of immersed boundary methods. As basic approximation technique we consider the finite element method with a mesh that does not match the boundary of the computational domain, and therefore Dirichlet boundary conditions need to be prescribed in an approximate way. As starting variational approach we consider Nitsche's methods, and we then move to two options that yield non‐symmetric problems but that turned out to be robust and efficient. The essential idea is to use the degrees of freedom of certain nodes of the finite element mesh to minimize the difference between the exact and the approximated boundary condition

Computational aeroacoustics of viscous low speed flows using subgrid scale finite element methods

María Jesús Samper — Tue, 03 Sep 2019 14:46:49 +0200

A methodology to perform computational aeroacoustics (CAA) of viscous low speed flows in the framework of stabilized finite element methods is presented. A hybrid CAA procedure is followed that makes use of Lighthill's acoustic analogy in the frequency domain. The procedure has been conceptually divided into three steps. In the first one, the incompressible Navier–Stokes equations are solved to obtain the flow velocity field. In the second step, Lighthill's acoustic source term is computed from this velocity field and then Fourier transformed to the frequency domain. Finally, the acoustic pressure field is obtained by solving the corresponding inhomogeneous Helmholtz equation. All equations in the formulation are solved using subgrid scale stabilized finite element methods. The main ideas of the subgrid scale numerical strategy are outlined and its benefits when compared to the Galerkin approach are described. As numerical examples, the aerodynamic noise generated by flow past a two-dimensional cylinder and by flow past two cylinders in parallel arrangement are addressed.

Mathematical models for thermally coupled low speed flows

María Jesús Samper — Tue, 03 Sep 2019 14:29:05 +0200

In this paper we review and clarify some aspects of the asymptotic analysis of the compressible Navier Stokes equations in the low Mach number limit. In the absence of heat exchange (the isentropic regime) this limit is well understood and rigorous results are available. When heat exchange is considered different simplified models can be obtained, the most famous being the Boussinesq approximation. Here a unified formal justification of these models is presented, paying special attention to the relation between the low Mach number and the Boussinesq approximations. Precise conditions for their validity are given for classical problems in bounded domains.

Unified Stabilized Finite Element Formulations for the Stokes and the Darcy Problems

María Jesús Samper — Tue, 03 Sep 2019 14:21:27 +0200

In this paper we propose stabilized finite element methods for both Stokes' and Darcy's problems that accommodate any interpolation of velocities and pressures. Apart from the interest of this fact, the important issue is that we are able to deal with both problems at the same time, in a completely unified manner, in spite of the fact that the functional setting is different. Concerning the stabilization formulation, we discuss the effect of the choice of the length scale appearing in the expression of the stabilization parameters, both in what refers to stability and to accuracy. This choice is shown to be crucial in the case of Darcy's problem. As an additional feature of this work, we treat two types of stabilized formulations, showing that they have a very similar behavior

A numerical approximation of the thermal coupling of fluids and solids

María Jesús Samper — Tue, 03 Sep 2019 14:14:16 +0200

In this article we analyze the problem of the thermal coupling of fluids and solids through a common interface. We state the global thermal problem in the whole domain, including the fluid part and the solid part. This global thermal problem presents discontinuous physical properties that depend on the solution of auxiliary problems on each part of the domain (a fluid flow problem and a solid state problem). We present a domain decomposition strategy to iteratively solve problems posed in both subdomains and discuss some implementation aspects of the algorithm. This domain decomposition framework is also used to revisit the use of wall function approaches used in this context.

On a multiscale approach to the transient Stokes problem: Dynamic subscales and anisotropic space–time discretization

María Jesús Samper — Tue, 03 Sep 2019 14:07:00 +0200

In this article, we analyze some residual-based stabilization techniques for the transient Stokes problem when considering anisotropic time–space discretizations. We define an anisotropic time–space discretization as a family of time–space partitions that does not satisfy the condition h2⩽Cδt with C uniform with respect to h and δt. Standard residual-based stabilization techniques are motivated by a multiscale approach, approximating the effect of the subscales onto the large scales. One of the approximations is to consider the subscales quasi-static (neglecting their time derivative). It is well known that these techniques are unstable for anisotropic time–space discretizations. We show that the use of dynamic subscales (where the subscales time derivatives are not neglected) solves the problem, and prove optimal convergence and stability results that are valid for anisotropic time–space discretizations. Also the improvements related to the use of orthogonal subscales are addressed.

The fixed-mesh ALE approach for the numerical approximation of flows in moving domains

María Jesús Samper — Tue, 03 Sep 2019 14:01:51 +0200

In this paper we propose a method to approximate flow problems in moving domains using always a given grid for the spatial discretization, and therefore the formulation to be presented falls within the category of fixed-grid methods. Even though the imposition of boundary conditions is a key ingredient that is very often used to classify the fixed-grid method, our approach can be applied together with any technique to impose approximately boundary conditions, although we also describe the one we actually favor. Our main concern is to properly account for the advection of information as the domain boundary evolves. To achieve this, we use an arbitrary Lagrangian–Eulerian framework, the distinctive feature being that at each time step results are projected onto a fixed, background mesh, that is where the problem is actually solved.

Finite element approximation of the three field formulation of the Stokes problem using arbitrary interpolations

María Jesús Samper — Tue, 03 Sep 2019 13:55:02 +0200

The stress-displacement-pressure formulation of the elasticity problem may suffer from two types of numerical instabilities related to the finite element interpolation of the unknowns. The first is the classical pressure instability that occurs when the solid is incompressible, whereas the second is the lack of stability in the stresses. To overcome these instabilities, there are two options. The first is to use different interpolation for all the unknowns satisfying two inf-sup conditions. Whereas there are several displacement-pressure interpolations that render the pressure stable, less possibilities are known for the stress interpolation. The second option is to use a stabilized finite element formulation instead of the plain Galerkin approach. If this formulation is properly designed, it is possible to use arbitrary interpolation for all the unknowns. The purpose of this paper is precisely to present one of such formulations. In particular, it is based on the decomposition of the unknowns into their finite element component and a subscale, which will be approximated and whose goal is to yield a stable formulation. A singular feature of the method to be presented is that the subscales will be considered orthogonal to the finite element space. We describe the design of the formulation and present the results of its numerical analysis.

Subscales on the element boundaries in the variational two-scale finite element method

María Jesús Samper — Tue, 03 Sep 2019 13:37:05 +0200

In this paper, we introduce a way to approximate the subscales on the boundaries of the elements in a variational two-scale finite element approximation to flow problems. The key idea is that the subscales on the element boundaries must be such that the transmission conditions for the unknown, split as its finite element contribution and the subscale, hold. In particular, we consider the scalar convection–diffusion–reaction equation, the Stokes problem and Darcy’s problem. For these problems the transmission conditions are the continuity of the unknown and its fluxes through element boundaries. The former is automatically achieved by introducing a single valued subscale on the boundaries (for the conforming approximations we consider), whereas the latter provides the effective condition for approximating these values. The final result is that the subscale on the interelement boundaries must be proportional to the jump of the flux of the finite element component and the average of the subscale calculated in the element interiors.

La ciencia a l'enginyeria. El llegat de l'école polytechnique

María Jesús Samper — Tue, 18 Jun 2019 11:13:15 +0200

Size effect and localization in J2 plasticity

María Jesús Samper — Mon, 17 Jun 2019 14:07:34 +0200

This paper studies the phenomenon of structural size effect and strain localization in J2 plasticity. Size effect is here understood as the change in the response of a given structure when the spatial dimensions are scaled up or down while the geometry and other relevant properties of the structure are preserved. The work exploits the advantages of the mixed displacement–pressure formulation in incompressible or quasi-incompressible situations. Elasto-J2-plastic constitutive behaviour with regularized softening is considered. Stability issues are discussed to ensure existence and uniqueness of the solution of the corresponding discrete finite element formulation. Numerical examples show that the formulation derived is able to solve a wide range of structural scales, including real life engineering applications. The results obtained do not suffer from spurious mesh dependence. Furthermore, the formulation includes the classical theories of perfect plasticity and linear fracture mechanics as limit cases.

Fuel cells state of the art

María Jesús Samper — Mon, 17 Jun 2019 13:54:07 +0200

Las ingenierias: Unas profesiones de largo recorrido

María Jesús Samper — Mon, 17 Jun 2019 13:48:06 +0200

A finite point method to solve shallow water equations.

María Jesús Samper — Mon, 17 Jun 2019 13:43:29 +0200

Optimizing rock cutting through computer simulation

María Jesús Samper — Mon, 17 Jun 2019 13:38:22 +0200

This paper presents an original thermomechanical model of rock cutting with evaluation of tool wear. The model has been developed within the framework of the discrete element method, which is a suitable numerical method to study problems of multiple material fractures likes those of rock cutting. The paper presents brief overview of the theoretical formulation, calibration of the discrete element model, and a number of numerical results obtained in simulation of rock cutting processes typical for underground excavation, using both roadheaders and TBMs.

A neural networks approach to aerofoil noise prediction

María Jesús Samper — Mon, 17 Jun 2019 13:31:29 +0200

A neural network noise prediction model for a turbulent boundary layer noise mechanism has been created using a feed forward multilayer perceptron and a noise spectrum database collected from a family of NACA 0012 areofoils. The results of the neural network model were compared against the Brooks model and it was found that the quality of the prediction was improved was improved over the entire range of the data. The model was also validated against experimental data not utilized the training of the neural, with positive results.

Melting and spread of polymer in fire with the particle finite element method

María Jesús Samper — Mon, 17 Jun 2019 13:20:41 +0200

A new computational procedure for analysis of the melting and flame spread of polymers under fire conditions is presented. The method, termed Particle Finite Element Method (PFEM), combines concepts from particle-based techniques with those of the standard finite element method (FEM). The key feature of the PFEM is the use of an updated Lagrangian description to model the motion of nodes (particles) in the thermoplastic material. Nodes are viewed as material points which can freely move and even separate from the main analysis domain representing, for instance, the effect of melting and dripping of polymer particles. A mesh connects the nodes defining the discretized domain where the governing equations are solved as in the standard FEM. An incremental iterative scheme for the solution of the nonlinear transient coupled thermal-flow problem, including loss of mass by gasification, is used. Examples of the possibilities of the PFEM for the modelling and simulation of the melting and flame spread of polymers under different fire conditions are described. Numerical results are compared with experimental data provided by NIST.

A numerical investigation of wind tunnel model deformations caused by the twin-sting support system

María Jesús Samper — Mon, 17 Jun 2019 13:04:24 +0200

This work presents a wing deformation analysis of a twin-sting-mounted commercial aircraft model. Twin-sting arrangements minimize flow disturbances around the model fuselage and tail; on the other hand, they cause important changes in the flow field around the wing and also increase aerodynamic interference at the wing and aeroelastic effects on the wing. In some cases, these effects can alter the normal downwash developed behind the wing, modifying the flow pattern at the tail. Consequently, when tail aerodynamics is a major concern, this kind of support interference should be carefully evaluated. The methodology developed in this work employs an unstructured FEM-based flow solver for computing aerodynamic loads. These loads are then transferred to a finite element structural model in order to assess the geometrical deformation of the wing caused by torsional moment exerted by supporting mechanism. The analysis described involves three different twin-sting support configurations taking into account angle of attack variations and Mach numbers spanning from subsonic of high transonic ranges.

New computational challenges in fluid-structure interactions problems

María Jesús Samper — Wed, 29 May 2019 14:21:40 +0200

In this paper the so-called added-mass effect is investigated from a different point of view of previous publications. The monolithic fluid structure problem is partitioned using a static condensation of the velocity terms. Following this procedure the classical stabilized projection method for incompressible fluid flows is introduced. The procedure allows obtaining a new pressure segregated scheme for fluid-structure interaction problems which has good convergent characteristics even for biomechanical application, where the added mass effect is strong. The procedure reveals its power when it is shown that the same projection technique must be implemented in staggered FSI methods.

Wireless sensor networks for strain monitoring during steel bridges launching

María Jesús Samper — Fri, 26 Apr 2019 11:47:05 +0200

n this paper, an experimental test performed on a hybrid steel plate girder was subjected to concentrated loads at the end of an unstiffened panel is presented. This load was intended to produce a typical reaction of the piers while launching steel girders in bridges. In this test, strain measurements were taken with conventional pre-wired gauges as well as with newly developed wirelessly connected strain-measuring system. Both measurements were carefully compared and the accuracy of the developed system was demonstrated. Results were also compared with numerical simulations deployed with FE models and on such a basis; the reliability of the developed wireless system was proven. Finally, suggestions of potential research trends in this area are provided

A monolithic FE formulation for the analysis of membranes in fluids

María Jesús Samper — Thu, 25 Apr 2019 12:12:03 +0200

We propose here an efficient approach for treating the interaction between membranes and fluids. Slight compressibility of the fluid is assumed. Classical total Lagrangian formulation including wrinkling is adopted for the membrane representation, whereas fluid is treated in an updated Lagrangian manner, developed in the current work. Assumption of slight compressibility of the fluid enables one to define the monolithic fluid-membrane system in a natural way. The displacements are the primary variables of both the fluid and the membrane domains. The formulation adopts the Particle Finite Element Method (PFEM) philosophy for free-surface identification and mesh regeneration. Three examples illustrate the functionality of the formulation in application to FSI problems involving motion of membranes in water

Nonlinear Formulations of a Four-Node Quasi-Conforming Shell Element

María Jesús Samper — Wed, 24 Apr 2019 11:12:16 +0200

The quasi-conforming technique was introduced in the 1980’s to meet the challenge of inter-elements conforming problems and give a unified treatment of both conforming and nonconforming elements. While the linear formulation is well established, the nonlinear formulation based on the quasi-conforming technique that includes geometric and material nonlinearity is presented in this paper. The formulation is derived in the framework of an updated Lagrangian stress resultant, co-rotational approach. The geometric nonlinear formulation provides solutions to buckling and postbuckling behaviour while the material nonlinear formulation considers the spread of plasticity within the element while maintaining an explicit construction of element matrices. Aside from the elasto-plastic constitutive relation, formulations on laminate composites and reinforced concrete are also presented.

The formulations of laminate composite and reinforced concrete material are present based on the layer concept, the material properties can vary throughout the thickness and across the surface of a shell element. The various failure criteria for laminate composite are included in the formulation which makes it possible to analyses the progressive failure of fibre and matrix. For the reinforced concrete material, the nonlinearities as a result of tensile cracking, tension stiffening between cracks, the nonlinear response of concrete in compression, and the yielding of the reinforcement are considered. The steel reinforcement is modeled as a bilinear material with strain hardening.

Advances in discrete element modelling of underground excavations

María Jesús Samper — Wed, 24 Apr 2019 10:49:44 +0200

The paper presents advances in the discrete element modelling of underground excavation processes extending modelling possibilities as well as increasing computational efficiency. Efficient numerical models have been obtained using techniques of parallel computing and coupling the discrete element method with finite element method. The discrete element algorithm has been applied to simulation of different excavation processes, using different tools, TBMs and roadheaders. Numerical examples of tunnelling process are included in the paper, showing results in the form of rock failure, damage in the material, cutting forces and tool wear. Efficiency of the code for solving large scale geomechanical problems is also shown

Personal information “management” (PIM), not just personal information “retrieval”

Scipedia content — Mon, 08 Apr 2019 11:33:31 +0200

Comparison of the characteristics and behaviour of people who are sorting and archiving physical and digital objects. There is limited selection –and also little interest– in tools for classifying digital objects that subsequently allow easy interaction with them or mental reflection while reviewing them. Thanks to the availability of inexpensive computer memory, people tend to save everything without categorizing, and trust –erroneously– only in good retrieval skills. Much more research in personal information management systems (PIM) is needed.

Wikipedia as controlled vocabulary: has the traditional authority control been surpassed?

Scipedia content — Mon, 08 Apr 2019 11:33:24 +0200

Wikipedia, the free encyclopaedia, is the first project to have been born specifically from and for the web and which has developed an authority control system for access to their information. Here, the different elements, procedures and principles which make up the Wikipedia authority control system is analysed, and a critical analogy is traced between them and those that meet the traditional authority control applied to bibliographical catalogues. From the critical comparison of both models, one wonders up to what point the authority control, constrained by the weight of tradition and by its hopeless adaptation to technology, has been surpassed by developments such as Wikipedia which are based on a philosophy of flexibility and common sense and where the rules are decided by and for the user. The enormous potential and reach of the Wikipedia authority model make it a true contender to become the normal system of access to the Semantic Web

Bibliometric assessment of universities with Scival of Elsevier

Scipedia content — Fri, 05 Apr 2019 16:30:08 +0200

Research, its management and its policies represent a major effort for Spanish universities but few of these institutions have a scientific information system with bibliometric indicators for decision making. Aware of this gap, Elsevier has launched Scival. It is a web platform intended to assess institutions through maps and indicators calculated from the Scopus database. In this article we review this new product. We first describe the scientific basis of the platform that is based on the works of Klavan and Bojack about co-citation maps of science and the identification of paradigms. Secondly we describe its interface and its utilities, paying particular attention to the so-called Wheel of science. Finally, we discuss some critical aspects of Scival

Evaluation of national libraries: creation of an international standard and its application to the National Library of Spain

Scipedia content — Fri, 05 Apr 2019 16:29:58 +0200

National libraries have recently adopted a quality assessment culture using performance indicators. The project for devising Technical Report ISO/TR 28118 regarding performance indicators for national libraries is explained from its beginnings. This is a specific common standard that permit benchmarking among similar institutions at the international level. The involvement of the international bodies IFLA, ISO and CENL in this initiative is described based on observation of the situations common to all national libraries. The technical process of drawing up the report is likewise described, along with its structure and contents. Also dealt with is the recent experience of the National Library of Spain in incorporating performance indicators to its evaluation processes and applying the ISO report indicators.

Integrating digital reference services into library management: experiences based on Koha

Scipedia content — Fri, 05 Apr 2019 16:29:49 +0200

The digital environment and information and communication technologies open up new ways of providing library services, including the reference service, the principal aim of which is to address users’ queries and information needs. Putting the reference service in place in this new environment requires redesigning the policies, procedures and resources applied to it and therefore an analysis of the services and functions of the computing tools available must be undertaken. Integrated library management systems which involve multiple functionalities for delivering services, or which expand the capacity for their delivery, must also respond to the requirements for putting this type of service in place. This article sets out the results obtained in a study carried out on several examples of integrating new reference services into a library management system (Koha), which not only enables these services to be delivered but also expands the options for using the data for their improvement and development.

InfoSud Digital: a virtual reference service for cooperative development

Scipedia content — Fri, 05 Apr 2019 16:29:40 +0200

InfoSud Digital promotes social awareness of international development collaborations. A VRS (Virtual Reference Service) using the Question Point tool from OCLC was created for this purpose. The ultimate goal is to create a network of information and documentation on cooperation for development. InfoSud Digital is a project developed by InfoSud, the information centre of the Patronat Sud-Nord of the University of Valencia.

Pregunte: las bibliotecas responden (Ask a librarian). Virtual reference services in Spain’s public libraries

Scipedia content — Fri, 05 Apr 2019 16:29:31 +0200

Review and development of the Spanish virtual reference service Pregunte: las bibliotecas responden (Ask a librarian). Description of main characteristics, workflows and statistical analysis. Description of the recently established chat service

Virtual reference in Seville University Library: a shared experience

Scipedia content — Fri, 05 Apr 2019 16:29:21 +0200

Reference services in academic libraries are far from dead and technologies of the social web are facilitating and encouraging an ever increasing demand for virtual reference with applications available to everyone. The open source software LibraryH3lp has enabled the Library of the University of Seville to establish a virtual reference service shared among 19 libraries to answer common and specialized questions and explain the use of the Fama library catalog. We present a first assessment of the service that will go live in the academic year 2009-2010.

The use of robots.txt and sitemaps in the Spanish public administration

Scipedia content — Fri, 05 Apr 2019 16:29:11 +0200

Robots.txt and sitemaps files are the main methods to regulate search engine crawler access to its content. This article explain the importance of such files and analyze robots.txt and sitemaps from more than 4,000 web sites belonging to spanish public administration to determine the use of these files as a medium of optimization for crawlers.

Research and development in digital preservation: an international review

Scipedia content — Fri, 05 Apr 2019 16:29:01 +0200

The article presents a survey of international research studies and development in digital preservation, devoting a section to the situation in Spain. The author outlines applications in areas such as institutional repositories, administrative records, personal archives, aerospace industry and museum archives, but the greatest attention is given to digital preservation applications in libraries and archives. The pre-eminent role of certain libraries and the national archives and records of certain countries is evident in an analysis of the protagonists of this research, as well as the emerging role of software companies. The major lines of research include the integration of tools to create integrated preservation systems.

Personal information management using concept mapping software

Scipedia content — Fri, 05 Apr 2019 16:28:52 +0200

Personal information management (PIM) raises some problems because the software tools that are used don’t adequately respond to user behaviour and activities. The concept and personal information management problems are reviewed, along with the software tools used for this task. A qualitative assessment explores whether an approach based on software tools for conceptual maps can address the problems discussed.

Digital reference: concept, technologies, and implementation in information centres

Scipedia content — Fri, 05 Apr 2019 16:28:40 +0200

Digital reference is the service offered by libraries and information centres so that users can ask questions through the Internet. The concept of digital reference is described, along with the different typologies based on various criteria. The technologies used today for receiving questions and sending answers are presented. Guidelines are suggested for implementing a digital reference service, based on four criteria: the actors involved, the techniques used, the available resources and the management of the service. It concludes by highlighting the value of digital reference as an online service that expands the range of patrons.

Reference services for a digital society

Scipedia content — Fri, 05 Apr 2019 16:28:27 +0200

Reference services have developed at the same pace as technology. Different aspects of the information society related to reference services provided by libraries and information centres are presented, including a description of the ubiquity, immediacy and participation that define the digital society. Digital reference is part of the information society and reflects the evolution of reference services offered by information centres. The characteristics of digital reference are described: telematic services, hybrid collections and skilled professionals.

Prácticas de las bibliotecas universitarias argentinas (Mercedes Patalano)

Scipedia content — Fri, 05 Apr 2019 16:28:18 +0200

Patalano, Mercedes (2008). Prácticas de las bibliotecas universitarias argentinas. Reflexiones críticas en el contexto de la comunicación académica y sus representaciones en la Web. Editorial Teseo, Buenos Aires, 160 pp. ISBN: 978 9871354191

Manual de indización: teoría y práctica (Isidoro Gil-Leiva)

Scipedia content — Fri, 05 Apr 2019 16:28:09 +0200

Gil-Leiva, Isidoro (2008). Manual de indización: teoría y práctica. Gijón: Trea, 432 p. (Biblioteca y administración cultural; 193). ISBN: 978 84 9704 367 0

OSTI-DOE, the source of energy information. Interview with Karen Spence

Scipedia content — Fri, 05 Apr 2019 16:28:01 +0200

An interview with Karen Spence, assistant director of Information Systems, Office of Scientific and Technical Information (OSTI), United States Department of Energy, describes the major OSTI databases, repositories and scientific and technical information co-operation projects (especially on energy and environment).

Aggregation of bibliometric indices to evaluate the scientific production of researchers

Scipedia content — Fri, 05 Apr 2019 16:27:52 +0200

In this paper we show that the aggregation of bibliometric indices is an appropriate way to evaluate scientific production of researchers because it allows us to develop much more precise new bibliometric indices that combine the advantages of each index that is aggregated.

Evolution of social network services

Scipedia content — Fri, 05 Apr 2019 16:27:40 +0200

The paper exposes a brief history of social network services on the Web that have evolved under the concept of Web 2.0, along with the most significant examples of these platforms. The concept of social networking and the main tests used to study them are explained, as well as their implications within different kinds of social capital (weak and strong ties) and the impact that the different web services can have on the relationship among their users.

The VideoActive project: Television as public service and audiovisual patrimony

Scipedia content — Fri, 05 Apr 2019 16:27:31 +0200

The need to preserve audiovisual archives and the possibilities for their dissemination resulting from digitisation have generated a growing interest in the development of platforms to provide access to their content. One of these platforms is VideoActive, a pan-European collaborative project that has developed a thematic approach to European history through TV and to the history of European TV. One of its key objectives is to encourage collaboration with the academic world. The consortium has developed its own technical infrastructure to offer at least 10,000 items from 10 different European archives, including that of Televisió de Catalunya, the Catalan public service broadcaster that seeks to contribute to international awareness of Catalan culture.

Meridià: a web portal to disseminate science from a comprehensive and cooperative view

Scipedia content — Fri, 05 Apr 2019 16:27:21 +0200

The proper functioning of the Research, Development and Innovation (R&D&I) cycle requires an efficient processing of scientific information. The Institute for Catalan Studies (IEC) possesses a scientific observatory which recently presented the web portal Meridià. From a global point of view, this project aims to be a cooperative initiative to integrate and share information with other agents of the scientific system, providing a thorough understanding of their environment and the evolution of the different areas in science and technology.

Strategies to improve the dissemination of research results with the Web 2.0

Scipedia content — Fri, 05 Apr 2019 16:27:11 +0200

Scientific communication is being enriched by the introduction of new ways of storage, publication and dissemination of the results. These include the services of the Web 2.0 which are still largely unknown to researchers. In this context the objective of this paper is to illustrate how we can strategically use Web Services 2.0 to disseminate and give greater visibility to scientific publications. To this end we present a series of services of interest to scientific communication (Blogger, Twitter, Facebook, Slideshare y E-Lis) and explain the role they can play in communicating scientific results. It also shows how these services should be logically interrelated, which we call the strategic dissemination cycle. In the last section, the authors collected a set of webmetric indicators classified into three groups (social influence, use, recognition) to evaluate the success of the dissemination strategy and the visibility of a work in the Web 2.0.

Retrieval of very large numbers of items in the Web of Science: an exercise to develop accurate search strategies

Scipedia content — Fri, 05 Apr 2019 16:27:00 +0200

The Web of Science interface counts at most 100,000 retrieved items from a single query. If the query results in a dataset containing more than 100,000 items the number of retrieved items is indicated as >100,000. The problem studied here is how to find the exact number of items in a query that leads to more than 100,000 items. One way to achieve this objective is presented. The retrieval of the entire scientific production from the United States in a specific year (2007) is counted and an advanced search strategy is designed. Different sections of items can be retrieved using the Source field of the database. A Boolean statement was created with the aim of eliminating overlapped sections and improving the accuracy of this search strategy.

ISOC database as information system: a major source for the analysis of Human and Social Sciences in Spain

Scipedia content — Fri, 05 Apr 2019 16:26:51 +0200

The ISOC database is presented as an information system that is very useful for the dissemination and the study of scientific production in human and social sciences in Spain since 1975. First of all, an historical overview is proposed. Secondly, quality elements that distinguish ISOC from other documentary systems are described. Thirdly, its suitability for bibliometric studies on the scientific production of these subjects published in Spain is discussed. Finally, some data about its use by the scientific and scholarly community are presented.

Use of patent databases as a tool for technology watch

Scipedia content — Fri, 05 Apr 2019 16:26:42 +0200

Given the importance of innovation and technology development in a country’s economy, there has been an increasing need for selecting indicators to measure the degree of innovation of its companies. The indicators related to patents offer an excellent measure of this capability and can be used as an important source of information by innovative organizations, although the studies assessing this utility are scarce. This study, conducted throughout 2007, proposes a technology watch oriented analysis of the level of use of patent databases from more than 500 Spanish companies that have issued at least one patent in the period 1988-1998, followed by discussion of the study results. The analysis took into account global data, company size and sector of activity

Google Scholar as a tool for research assessment

Scipedia content — Fri, 05 Apr 2019 16:26:32 +0200

Google Scholar is a search engine that specializes in scientific information and in the identification of the citations that academic papers receive, making it a strong competitor for other citations indexes. For this reason, several studies have attempted to evaluate its capacity as a bibliometric tool. Due to this interest, we present an introduction to its use and the advantages and disadvantages versus Scopus and Web of Science. First, its way of collecting information and features of its interface are analyzed. The following section describes the results that Google Scholar generates. Thirdly, we analyze the coverage of information sources and the different document types to be found, showing how this coverage universe offers different citations versus other products. Finally, we specify the standardization problems of Google Scholar and offer a number of precautions that must be taken into account when using Google Scholar as an evaluation tool.

Spanish public universities in Google Scholar: presence, evolution and coverage of their scientific output

Scipedia content — Fri, 05 Apr 2019 16:26:23 +0200

The validity of Google Scholar as a service that reflects properly the scientific output of a university is analyzed, comparing its coverage of Spanish public universities with that of Scopus. The presence and evolution of scientific documentation on the websites of the Spanish public universities from January to July (both months inclusive) 2009 is also studied. The results show that, despite finding some interrelationship between Scholar and Scopus concerning the productivity of institutions, there are large differences in the total results that override the latter as a valid reflection of university productivity. Finally, Scholar shows positive, albeit modest, growth during the studied period for most university websites analyzed

Science and us

Scipedia content — Fri, 05 Apr 2019 16:26:14 +0200

Science is the most refined cultural element to describe and manage the environment. It is the result of a permanent evolutionary algorithm and represents an adaptive biological advantage for the human species. Science evolves socially through physical records and information media, whose changes influence both science and society. Information professionals have been managing these physical records or knowledge containers. The technodigital revolution grows an industrialized information society where science is a productive workforce, with a neurodigital nature, and develops as a collective enterprise. Science containers are now very changeable, plural, segmented, networking, and take on a business look: they become “specific information platforms”. Information professionals’ position is rather weak, but they have the possibility to turn into information engineers, to participate in some of those platforms and to compete individually as information managers in the science arena.

Bases de datos de libre acceso difundidas por la Administración General del Estado (L. Fernando Ramos-Simón)

Scipedia content — Fri, 05 Apr 2019 16:26:01 +0200

Ramos-Simón, Luis-Fernando (2008). Bases de datos de libre acceso difundidas por la Administración General del Estado. Grupo Publidoc-UCM, coord. Madrid: Ministerio de Cultura, Editorial Complutense, 349 pp. ISBN: 978 84 7491 940 0

Social networks: beyond privacy

Scipedia content — Fri, 05 Apr 2019 16:25:50 +0200

Last February, following a change in Facebook’s use policies, a discussion about social networks began in IweTel, expanding on multiple facets of previous messages to the list. Topics included: the policies of use and their acceptance by each individual; the privacy of information and its management; the differences between cloud computing and social networks; and the need to train users in the correct use of social networks as part of an information professional’s profile.

Swets annual user meeting in Barcelona

Scipedia content — Fri, 05 Apr 2019 16:25:40 +0200

Summary of developments presented at the traditional annual congress of Swets users held on June 4, 2009 in Barcelona: the tool SwetsWise Selection Support, PressDisplay news portal, the ALPSP Learned Journals Collection, and the e-book platform MyiLibrary. e-Books sales are soaring.

Premis Workshop in Rome

Scipedia content — Fri, 05 Apr 2019 16:25:31 +0200

A Premis Workshop (PREservation Metadata: Implementation Strategies) was held in Rome on 5-6 February 2009. The event, organized by the Foundation Rinascimento Digitale, was attended by two members of the Premis Editorial Committee: Rebecca Guenther (Library of Congress) and Angela Dappert (British Library). Some preservation metadata implementation projects were presented.

Fesabid 2009: the interinformation conference

Scipedia content — Fri, 05 Apr 2019 16:25:23 +0200

The 11th Spanish Documentation Conference (Jornadas Españolas de Documentación) was held May 20-22, 2009 in Saragossa, Spain, organized by the Spanish Federation of Societies of Archivology, Librarianship, Special librarianship and Museology (Fesabid). Socioprofessional networks served as a thread this year and provided cohesion to a large number of presentations by professionals from different areas of libraries, documentation and archives. We discuss some of them.

Generation reference management software: comparative analysis of RefWorks, EndNote web and Zotero

Scipedia content — Fri, 05 Apr 2019 16:25:14 +0200

Reference managing tools are one of the most useful devices for researchers and librarians due to their ability to compile, storeand format information related to different products, sources and types of records. In recent years a new generation of reference-managing software has appeared. These new tools include applications from the new technological context that have contributed to reinforcing their capacity and potential. An overview of these tools and their applications is offered. We also makes a comparative analysis of the different products with a view to highlighting their strengths as well as the elements that could be improved in each tool.

The Spanish science as seen through the Web of Science (1996-2007): the disciplines

Scipedia content — Fri, 05 Apr 2019 16:25:05 +0200

From the information provided for free by Thomson Reuters in ScienceWatch.com, production and citation dataof the scientific disciplines are analyzed for Spain, determining the relative weight of each one both nationally and internationally throughout the past 10 years.

Citation patterns of the journal El profesional de la información (EPI)

Scipedia content — Fri, 05 Apr 2019 16:24:56 +0200

Analysis of the citations received by the journal El profesional de la información (EPI) according to the databases ISI Science Citation Index (WoS) from Thomson Reuters, and Scopus from Elsevier, which index the journal since 2006. There are three main groups (or themes) recognized, that potentially can generate citations: bibliometrics, medicine, and library and information science in Spanish.

Biometric facial identification

Scipedia content — Fri, 05 Apr 2019 16:24:47 +0200

The identification of individuals on television using facial recognition biometrics can help the work of audiovisual documentation departments. Basic biometrics concepts are presented, as well as some of the biometrics software available. Opportunities and potential uses for onomastic information management with the aim to partially automate people’s identification in television archives are discussed.

Local search replaces the classic telephone directory

Scipedia content — Fri, 05 Apr 2019 16:24:39 +0200

The publishers of yellow pages and business directories are suffering strong competition from the internet and are forced to seek new ways of income, taking refuge in local markets and more personalized services to their users.

The information professional in crisis

Scipedia content — Fri, 05 Apr 2019 16:24:30 +0200

The profession of information scientist is considered with a historical perspective and the author tries tofigure out the reason for his identity crisis. It is suggested that uniting with librarians and archivists has proved harmful in the long run, perhaps even a drag on their development and their more dynamic image. The author doesn’t expect the situation will change in the short term.

Online communication in the health field. Value of the infography

Scipedia content — Fri, 05 Apr 2019 16:24:22 +0200

The great interest that health generates in people has led to several Spanish institutions of the health sector to improve the communication value of newsletters, online patients forums, brochures, online videos, mobile phone and infography, among others. The aim to educate the patients and differing themselves strategically from other institutions finds in the technology a strategic partner that affords many benefits to the target audience (immediacy, interactivity) and to the organization (brand image, time optimization). One of the most representative initiatives of this trend is the creation of infographies about health matters that, respecting the scientific, informative, didactic and ethical rigour, are spread throughout different media.

Information on internationalization in Castilla-Leon companies

Scipedia content — Fri, 05 Apr 2019 16:24:13 +0200

Management decision to initiate or develop internationalization depends on the ability to take advantage of opportunities afforded by foreign markets. Factors determining whether these opportunities may be profited from are: access to information and the cognitive approach of the decision-making agent, namely the manager. In our research we explore which sources of information provide the stimuli impacting the decision to internationalize and assess the influence of management’s cognitive approach. To achieve this we conducted a survey amongst Spanish firms in the region of Castilla and León in two specific areas: “information technologies” and “natural stone”. Informative stimuli are split into three concepts (appealing factors, barriers and support) and we draw on several sources of information (Icex, Excal, Chambers of Commerce and trade associations). We address two cognitive areas: proactivity and level of knowledge. Findings highlight the relative importance of the different sources of information explored in the analysis. Our research also evidences how the information received by managers merges with their own cognitive approaches forming the basis to assess the factors impacting the decision to internationalize.

Personal information management: elements, activities and integration

Scipedia content — Fri, 05 Apr 2019 16:24:05 +0200

Personal information management (PIM) studies how people should organize and use the information they get to solve everyday needs, in order to take full advantage of personal resources (time, money, energy, attention) and thereby increase productivity and improve their quality of life. This paper presents the components and activities where PIM is articulated and describes how to promote the integration of personal information that is generally scattered in different forms, applications and devices.

Risk communication and web-based information systems: five models

Scipedia content — Fri, 05 Apr 2019 16:23:57 +0200

Public administration in the developed countries is designing information initiatives to manage risk information using web-based systems. These sites are intended to deliver information to citizens, but also have valuable information for experts and authorities. Five web sites are compared and a simple methodology is provided to extract conclusions and propose recommendations in an information management dimension that is key to saving not only property but human lives as well.

The role of the digital information sources in the art market prices

Scipedia content — Fri, 05 Apr 2019 16:23:45 +0200

The objective of this study is to measure the relationship between the digital information sources (Google, Yahoo and Encyclopaedia Britannica) and the turnover of the international art auction houses. The effect of the art turnover (estimated during the period 1997-2006) on the information sources (estimated on January 2007) was analyzed. The results showed a major influence of turnovers on the Net (mainly Google than Yahoo) than on the Encyclopaedia sources. Also, the information sources on the Net only affect the future art auction house’s turnovers (Google is more useful than Yahoo)

Knowledge life cycles: renewal and obsolescence

Scipedia content — Fri, 05 Apr 2019 16:23:34 +0200

The traditional need to collect, care for and make available a huge collection of physical items has shaped the education, work and even the sense of identity of information professionals, as well as the services provided by libraries. As the infrastructure related to physical items increasingly disappears from our responsibilities, we need to fundamentally rethink how we go about our mission to collect, organize, preserve and make available the information resources of the human enterprise. Various topics that are transforming the information professional’s environment are discussed, including digitization, digital collections, open access, information abundance, etc.

Personal information management of ICT’s intensive users

Scipedia content — Fri, 05 Apr 2019 16:23:22 +0200

A large part of the research on personal information management is scattered through many journals due to the intrinsic characteristics of this topic. This work tries to compile a more complete, global and integrated study of that type of management strategies. Our study offers an analytical model of the informational behaviour of a group of individuals (students of an e-learning university, UOC) who have a positive perception of the information and communication technologies and use them intensively in their academic, professional and everyday contexts. From this qualitative research (24 interviews and content analysis), four user profiles (reactive, passive, comprehensive and proactive) have been identified in relation to personal information management and its relevant variables: access, management and use of information, cognitive style, attitude, information-related competencies, ICT perception, and academic, professional and everyday contexts. These profiles show the differences in information behaviour for each context (daily life, professional and academic). Identification of the user profiles was the essential first step in a user centered service design that addresses the specific intervention/contribution appropriate to each user type, taking into account tool and process requirements needed for them to develop efficient information behaviours