Scipedia: Documents published in 2008

Semantic service matchmaking in the atm domain considering infrastructure capability constraints

Scipedia content — Wed, 14 Oct 2020 15:46:52 +0200

In a service-oriented environment business processes flexibly build on software services provided by systems in a network. A key design challenge is the semantic matchmaking of business processes and software services in two steps: 1. Find for one business process the software services that meet or exceed the BP requirements; 2. Find for all business processes the software services that can be implemented within the capability constraints of the underlying network, which poses a major problem since even for small scenarios the solution space is typically very large. In this chapter we analyze requirements from mission-critical business processes in the Air Traffic Management (ATM) domain and introduce an approach for semi-automatic semantic matchmaking for software services, the System-Wide Information Sharing (SWIS) business process integration framework. A tool-supported semantic matchmaking process like SWIS can provide system designers and integrators with a set of promising software service candidates and therefore strongly reduces the human matching effort by focusing on a much smaller space of matchmaking candidates. We evaluate the feasibility of the SWIS approach in an industry use case from the ATM domain.

Document type: Part of book or chapter of book

Europe and central asia region how resilient is the energy sector to climate change

Scipedia content — Wed, 14 Oct 2020 15:33:54 +0200

The energy sector is sensitive to changes in seasonal weather patterns and extremes e.g. floods, droughts, fire, storm, and landslide, that can affect the supply of energy, impact transmission capacity, disrupt oil and gas production, and impact the integrity of transmission pipelines and power distribution. Much infrastructure, built to design codes based on historic climate data, will require decisions in coming years regarding rehabilitation, upgrade or replacement. This poses both a challenge and an opportunity for adaptation. This review is one of a series of sector?based papers commissioned as background to the report managing uncertainty: adapting to climate change in ECA countries targeted at internal World Bank audiences as well as counterparts in client countries.

Document type: Book

Inclusion of a Second-Order Prior into Semi-Global Matching

Scipedia content — Wed, 14 Oct 2020 15:28:54 +0200

Today's stereo vision algorithms and computing technology allow real-time 3D data analysis, for example for driver assistance systems. A recently developed Semi-Global Matching (SGM) approach by H. Hirschmuller became a popular choice due to performance and robustness. This paper evaluates different parameter settings for SGM, and its main contribution consists in suggesting to include a second order prior into the smoothness term of the energy function. It also proposes and tests a new cost function for SGM. Furthermore, some preprocessing (edge images) proved to be of great value for improving SGM stereo results on real-world sequences, as previously already shown by S. Guan and R. Klette for belief propagation. There is also a performance gain for engineered stereo data (e.g.) as currently used on the Middlebury stereo website. However, the fact that results are not as impressive as on the .enpeda.. sequences indicates that optimizing for engineered data does not neccessarily improve real world stereo data analysis.

Document type: Part of book or chapter of book

An architecture for supporting network fault recovery management

Scipedia content — Wed, 14 Oct 2020 15:10:46 +0200

Highly available and resilient networks play a decisive role in today's networked world. As network faults are inevitable and networks are becoming constantly intricate, finding effective fault recovery solutions in a timely manner is becoming a challenging task for administrators. Therefore, an automated mechanism to support fault resolution is essential towards efficient fault handling process. In this paper we propose an architecture to support automated fault recovery in terms of traffic engineering, recovery knowledge discovery and automated recovery planning. We base our discussion on an application scenario for recovery from border router failure to maintain optimized configuration of outbound inter-domain traffic.

Document type: Part of book or chapter of book

Teletraffic Performance Analysis of Multi-class OFDM-TDMA Systems with AMC

Scipedia content — Wed, 14 Oct 2020 15:10:18 +0200

In traditional channelized multiple access systems, such as TDMA and FDMA, each user is assigned a fixed amount of bandwidth during the whole connection time, and the teletraffic performance in terms of time congestion, call congestion and traffic congestion can easily be obtained by using the classical Erlang-B formula. However, with the introduction of adaptive modulation and coding (AMC) scheme employed at the physical layer, the allocation of bandwidth to each user is no longer deterministic, but dynamically based on the wireless channel conditions. Thus a new connection attempt will be blocked with a certain probability depending on the state of the system and the bandwidth requirement of the connection attempt. In this paper, we present an integrated analytical model of multi-rate loss system with state-dependent blocking to evaluate the performance of multi-class OFDM-TDMA systems with AMC scheme.

Document type: Part of book or chapter of book

Accessibility in information retrieval

Scipedia content — Wed, 14 Oct 2020 14:47:38 +0200

This paper introduces the concept of accessibility from the field of transportation planning and adopts it within the context of Information Retrieval (IR). An analogy is drawn between the fields, which motivates the development of document accessibility measures for IR systems. Considering the accessibility of documents within a collection given an IR System provides a different perspective on the analysis and evaluation of such systems which could be used to inform the design, tuning and management of current and future IR systems.

Document type: Part of book or chapter of book

Transportation fuel use technology and standards the role of credibility and expectations

Scipedia content — Wed, 14 Oct 2020 14:43:54 +0200

There is a debate among policy analysts about whether fuel taxes alone are the most effective policy to reduce fuel use by motorists, or whether to also use mandatory standards for fuel efficiency. A problem with a policy mandating fuel economy standards is the"rebound effect,"whereby owners with more efficient vehicles increase vehicle usage. If an important part of negative externalities from transport are associated with vehicle kilometers (accidents, congestion, road wear) rather than fuel consumption, the rebound effect increases negative externalities. Taxes and standards should be mutually supportive because fuel taxes often meet political resistance. Over time, fuel efficiency standards can reduce political resistance to fuel taxes. Thus, by raising fuel efficiency standards now, politicians may be able to pursue higher fuel tax paths in the future. Another argument in support of fuel efficiency standards and similar policies is that standards to a greater extent than taxes can be announced in advance and still be credible and change the behavior of inventors, firms, and other agents in society. A further argument is that standards can be used with greater force and commitment through international coordination.

Document type: Book

Personalized public transport guidance using mobile end devices

Scipedia content — Wed, 14 Oct 2020 14:43:12 +0200

Mobility is a vital part of human life. Mobility needs can be met in a variety of ways: motorized and non-motorized individual traffic, local public transport using buses and trains, or mixed systems like taxis and park and ride systems. Individual traffic in particular causes major environment problems and problems of traffic congestion. Strengthening public transport is often favored, but this preference is not reflected in the number of local transport users. This phenomenon can be explained by the fact that a central problem involved in local public transport usage is its complexity. The article presented here develops demands on a personalized local public transport guidance system, analyzes existing systems and presents a solution for a personalized support system for users of local public transport systems. The software Hermes was developed for this purpose. It accompanies the travelers through all steps of public traffic usage from checking time tables to purchasing tickets to a navigation system for pedestrians guiding the user to a street address destination.

Document type: Part of book or chapter of book

Modelling Complex Intermodal Freight Flows

Scipedia content — Wed, 14 Oct 2020 14:40:41 +0200

In regions with an extensive waterway network intermodal transport including inland navigation is a good alternative for unimodal road transport. Intermodal transport networks exhibit an increased complexity due to the inclusion of multiple transport modes, multiple decision makers and multiple types of load units. A discrete event simulation methodology is proposed to understand the network dynamics and analyze policy measures with the intention of stimulating intermodal barge transport. The simulation model allows to quantify a number of network properties resulting from the interaction of freight flows. The intermodal hinterland network of the port of Antwerp serves as the real-world application in this study. Various aspects in the modelling process are discussed and a first potential policy is analysed.

Document type: Part of book or chapter of book

Emon embodied monitorization

Scipedia content — Wed, 14 Oct 2020 14:03:38 +0200

Serie : Lecture Notes in Computer Science, vol. 5859 The amount of seniors in need of constant care is rapidly rising: an evident consequence of population ageing. There are already some monitorization environments which aim to monitor these persons while they remain at home. This, however, although better than delocalizing the elder to some kind of institution, may not still be the ideal solution, as it forces them to stay inside the home more than they wished, as going out means lack of accompaniment and a consequent sensation of fear. In this paper we propose EMon: a monitorization device small enough to be worn by its users, although powerful enough to provide the higher level monitorization systems with vital information about the user and the environment around him. We hope to allow the representation of an intelligent environment to move with its users, instead of being static, mandatorily associated to a single physical location. The first prototype of EMon, as presented in this paper, provides environmental data as well as GPS coordinates and pictures that are useful to describe the context of its user.

Document type: Part of book or chapter of book

Traffic networks and flows over time

Scipedia content — Wed, 14 Oct 2020 13:55:27 +0200

In view of the steadily growing car traffic and the limited capacity of our street networks, we are facing a situation where methods for better traffic management are becoming more and more important. Studies [92] show that an individual "blind" choice of routes leads to travel times that are between 6% and 19% longer than necessary. On the other hand, telematics and sensory devices are providing or will shortly provide detailed information about the actual traffic flows, thus making available the necessary data to employ better means of traffic management.

Document type: Part of book or chapter of book

The air traffic flow management problem an integer optimization approach

Scipedia content — Wed, 14 Oct 2020 13:55:03 +0200

In this paper, we present a new Integer Program (IP) for the Air Traffic Flow Management (ATFM) problem. The model we propose provides a complete representation of all the phases of each flights, i.e., the phase of taking-off, of cruising and of landing; suggesting all the actions to be implemented to achieve the goal of safe, efficient, and expeditious aircraft movement. The distinctive feature of the model is that it allows rerouting decisions. These decisions are formulated by means of "local" conditions, which allow us to represent such decisions in a very compact way by only introducing new constraints. Moreover, to strengthen the polyhedral structure of the underlying relaxation, we also present three classes of valid inequalities.\r \r We report short computational times (less than 15 minutes) on instances of the size of the US air traffic control system that make it realistic that our approach can be used as the main engine of managing air traffic in the US.

Document type: Part of book or chapter of book

Route Optimization in IP Networks

Scipedia content — Wed, 14 Oct 2020 13:54:24 +0200

The performance and reliability of the Internet depend, in large part, on the operation of the underlying routing protocols. Todays IP routing protocols compute paths based on the network topology and configuration parameters, without regard to the current traffic load on the routers and links. The responsibility for adapting the paths to the prevailing traffic falls to the network operators and management systems. This chapter discusses the modeling and computational challenges of optimizing the tunable parameters, starting with conventional intradomain routing protocols that compute shortest paths as the sum of configurable link weights. Then, we consider the problem of optimizing the interdomain routing policies that control the flow of traffic from one network to another. Optimization based on local search has proven quite effective in grappling with the complexity of the routing protocols and the diversity of the performance objectives, and tools based on local search are in wide use in todays large IP networks.

Document type: Part of book or chapter of book

MATSim-T

Scipedia content — Wed, 14 Oct 2020 13:54:11 +0200

Micro-simulations for transport planning are becoming increasingly important in traffic simulation, traffic analysis, and traffic forecasting. In the last decades the shift from using typically aggregated data to more detailed, individual based, complex data (e.g. GPS tracking) andthe continuously growing computer performance on fixed price level leads to the possibility of using microscopic models for large scale planning regions. This chapter presents such a micro-simulation. The work is part of the research project MATSim (Multi Agent Transport Simulation, http://matsim.org). In the chapter here the focus lies on design and implementation issues as well as on computational performance of different parts of the system. Based on a study of Swiss daily traffic ca. 2.3 million individuals using motorized individual transport producing about 7.1 million trips, assigned to a Swiss network model with about 60,000 links, simulated and optimized completely time-dynamic for a complete workday it is shown that the system is able to generate those traffic patterns in about 36 hours computation time.

Document type: Part of book or chapter of book

Impact of benefit sharing among companies in the implantation of a collaborative transportation system an application in the furniture industry

Scipedia content — Wed, 14 Oct 2020 13:04:52 +0200

Transportation has become an increasingly important part of the Canadian furniture industry supply chain. Even when different furniture companies ship to the same regions, the same cities and/or the same furniture retailers, coordination between two or more companies is rare. Recently, interest in collaborative transportation planning to support coordination has intensified as important potential benefits (e.g. cost and delivery time reductions) have been identified. Even though substantial benefits can be realized, the methods for sharing benefits among companies as well as the leadership of the collaboration implementation are key issues in deciding on a logistics scenario for the collaboration. In this paper, the impacts of these two key issues are illustrated using an industrial case study of four Canadian furniture companies shipping to the United-States.

Document type: Part of book or chapter of book

Supply chain security guide

Scipedia content — Wed, 14 Oct 2020 12:58:33 +0200

A supply chain is a system of resources, organizations, people, technologies, activities and information involved in the act of transporting goods from producer to consumer and user. This (SCS) guide is intended for trade and transport government officials, port authorities and transport, cargo and logistics communities, in particular in developing countries. The purpose of the guide is to make concerned trade and transport-related officials, managers and personnel in developing countries acquainted with, and aware of, the many initiatives mushrooming in the field of supply chain security, what these will mean for their respective organizations, and how to tackle the inlaid challenges. This chapter attempts to clarify the background and current status of the multitude of programs that exist across the world today. This is achieved by, firstly, giving a brief account of the changing security environment (post 9/11) and its resulting implications for SCS programs. This is important as it helps to explain the motivation of the programs which are later expanded upon in more detail within the chapter. Within this section, the motivations for different types of programs, not directly linked to the events of 9/11 but to other reasons, such as combating illegal activities, enhancement of efficiency and standardization are also explained. Secondly, a list of the main programs is present under four main subheadings: compulsory programs, major voluntary programs, regional or national programs, and others. Tables are presented at the end of the section summarizing the main points of each program. Finally, some of the issues surrounding the programs are presented in the concluding section.

Document type: Book

Time dependent sharc routing

Scipedia content — Wed, 14 Oct 2020 12:56:20 +0200

During the last years, many speed-up techniques for Dijkstra 's algorithm have been developed. As a result, computing a shortest path in a staticroad network is a matter of microseconds. However, only few of those techniques work in time-dependentnetworks. Unfortunately, such networks appear frequentely in reality: Roads are predictably congestured by traffic jams, and efficient timetable information systems rely on time-dependent networks. Hence, a fast technique for routing in such networks is needed. In this work, we present an exacttime-dependent speed-up technique based on our recent SHARC-algorithm. As a result, we are able to efficiently compute shortest paths in time-dependent continental-sized transportation networks, both of roads and of railways.

Document type: Part of book or chapter of book

Sessions and pipelines for structured service programming

Scipedia content — Wed, 14 Oct 2020 12:51:15 +0200

Service-oriented computing is calling for novel computational models and languages with primitives for client-server interaction, orchestration and unexpected events handling. We present CaSPiS , a process calculus where the notions of session and pipelining play a central role. Sessions are two-sided and can be equipped with protocols executed by each side. Pipelining permits orchestrating the flow of data produced by different sessions. The calculus is also equipped with operators for handling (unexpected) termination of the partner's side of a session. Several examples are presented to provide evidence for the flexibility of the chosen set of primitives. Our main result shows that in CaSPiS it is possible to program a "graceful termination" of nested sessions, which guarantees that no session is forced to hang forever after the loss of its partner.

Document type: Part of book or chapter of book

UAS Safety in Non-Segregated Airspace

Scipedia content — Tue, 29 Sep 2020 09:55:26 +0200

Unmanned Aerial Systems (UAS) are set to become part of everyday air traffic operations perhaps within the next few years; however there are significant challenges that need to be addressed in order to seamlessly introduce UAS into non segregated airspace. This chapter discusses some of the identified safety challenges in achieving this objective in the context of the current regulatory framework. It also takes a look at how one might rigorously argue the safety of UAS operations in non-segregated airspace from an Air Traffic Management (ATM) perspective. The chapter draws upon the experience of the authors’ in the UAS domain, more specifically the lessons learnt from a number of safety assessments for flying UAS as Operational or General Air Traffic (OAT or GAT) inside and outside segregated airspace. Most UAS operations are currently constrained to designated danger areas or within temporary restricted areas of airspace, commonly known as segregated airspace, or are flown under special arrangements over the sea. On some occasions, UAS operations are permitted in an extremely limited environment outside segregated airspace. To exploit fully the unique operational capabilities of current and future UAS and thus realise the potential commercial benefits of UAS, there is a desire to be able to access all classes of airspace and operate across national borders and airspace boundaries. Such operations must be acceptably safe but regulation should not become so inflexible or burdensome that the commercial benefits are lost. The viability of the commercial market for UAS especially in the civil market is heavily dependent on unfettered access to the same airspace as manned civilian operations. Whilst it is essential that UAS demonstrate an equivalent level of safety compared to manned operations the current regulatory framework has evolved around the concept of the pilot-inthe-cockpit. There is a need to develop UAS solutions that assure an equivalent level of safety for UAS operations, which in turn will require adaptation of the current regulatory framework to allow for the concept of the pilot-not-in-the-cockpit without compromising the safety of other airspace users. One of the major issues facing UAS operations is the demonstration of equivalence (in particular for See and Avoid) in the context of an evolving ATM environment. It is very important to understand that the current ATM environment is not static. Achieving equivalence with manned operations is not a fixed target as there are many significant changes proposed that aim to improve operational efficiency and performance or enhance safety. On the whole proposed changes to the ATM environment could be seen

Document type: Part of book or chapter of book

Development of a 5 degree of freedom towfish and its control strategy

Scipedia content — Tue, 29 Sep 2020 09:47:45 +0200

This paper describes the development of a five degree of freedom towed underwater vehicle designed for condition monitoring of undersea pipelines. Its innovative design, with 6 fins actuated by 5 motors adding heave and sway capabilities to the yaw, roll and pitch movements possible in traditional designs, is explained. The parameters influencing the stability and the design in general are analyzed. A Control strategy for this design of highly coupled movements and control modes encompassing all the operational scenarios, are presented.

Document type: Part of book or chapter of book

International Mobility of Researchers and Scientists: Policy Options for Turning a Drain into a Gain

Scipedia content — Wed, 23 Sep 2020 10:45:00 +0200

High demand for researchers and scientists has led to an increase in skilled migration in recent years. The paper focuses on improving our understanding of the push and pull factors affecting the migration decisions of researchers and scientists from developing countries and discusses policy options for maximizing the potential gains associated with international mobility of advanced human capital. Evidence suggests that a reasonable salary level should be guaranteed but that return decisions of researchers and scientists are primarily shaped by factors such as the quality of the research environment, professional reward structures and access to state-of-the-art equipment. Document type: Part of book or chapter of book

Bounds for quantities of interest and adaptivity in the Element Free Galerkin method

María Jesús Samper — Mon, 28 Oct 2019 14:59:03 +0100

A novel approach for implicit residual-type error estimation in mesh-free methods and an adaptive refinement strategy are presented. This allows computing upper and lower bounds of the error in energy norm with the ultimate goal of obtaining bounds for outputs of interest. The proposed approach precludes the main drawbacks of standard residual type estimators circumventing the need of flux-equilibration and resulting in a simple implementation that avoids integrals on edges/sides of a domain decomposition (mesh). This is especially interesting for mesh-free methods. The adaptive strategy proposed leads to a fast convergence of the bounds to the desired precision.

Small-scale gravitational instabilities under the oceans: implications for the evolution of oceanic lithosphere and its expression in geophysical observables

María Jesús Samper — Mon, 28 Oct 2019 14:52:28 +0100

Sublithospheric small-scale convection (SSC) is thought to be responsible for the flattening of the seafloor depth and surface heat flow observed in mature plates. Although the existence of SSC is generally accepted, its ability to effectively produce a constant lithospheric thickness (i.e. flattening of observables) is a matter of debate. Here we study the development and evolution of SSC with a 2D thermomechanical finite-element code. Emphasis is put on (i) the influence of various rheological and thermophysical parameters on SSC, and (ii) its ability to reproduce geophysical observables (i.e. seafloor depth, surface heat flow, and seismic velocities). We find that shear heating plays no significant role either in the onset of SSC or in reducing the lithospheric thickness. In contrast, radiogenic heat sources and adiabatic heating exert a major control on both the vigour of SSC and the thermal structure of the lithosphere. We find that either dislocation creep, diffusion creep, or a combination of these mechanisms, can generate SSC with rheological parameters given by laboratory experiments. However, vigorous SSC and significant lithospheric erosion are only possible for relatively low activation energies.

Modelling gravitational instabilities: Slab break–off and Rayleigh–Taylor diapirism

María Jesús Samper — Mon, 28 Oct 2019 14:46:56 +0100

A non-standard new code to solve multiphase viscous thermo–mechanical problems applied to geophysics is presented. Two numerical methodologies employed in the code are described: A level set technique to track the position of the materials and an enrichment of the solution to allow the strain rate to be discontinuous across the interface. These techniques have low computational cost and can be used in standard desktop PCs. Examples of phase tracking with level set are presented in two and three dimensions to study slab detachment in subduction processes and Rayleigh–Taylor instabilities, respectively. The modelling of slab detachment processes includes realistic rheology with viscosity depending on temperature, pressure and strain rate; shear and adiabatic heating mechanisms; density including mineral phase changes and varying thermal conductivity. Detachment models show a first prolonged period of thermal diffusion until a fast necking of the subducting slab results in the break–off. The influence of several numerical and physical parameters on the detachment process is analyzed: The shear heating exerts a major influence accelerating the detachment process, reducing the onset time to one half and lubricating the sinking of the detached slab. The adiabatic heating term acts as a thermal stabilizer. If the mantle temperature follows an adiabatic gradient, neglecting this heating term must be included, otherwise all temperature contrasts are overestimated. As expected, the phase change at 410 km depth (olivine–spinel transition) facilitates the detachment process due to the increase in negative buoyancy. Finally, simple plume simulations are used to show how the presented numerical methodologies can be extended to three dimensions.

Bounds of functional outputs for parabolic problems. Part I: Exact bounds of the Discontinuous Galerkin time discretization

María Jesús Samper — Mon, 28 Oct 2019 14:40:07 +0100

Classical implicit residual type error estimators require using an underlying spatial finer mesh to compute bounds for some quantity of interest. Consequently, the bounds obtained are only guaranteed asymptotically that is with respect to the reference solution computed with the fine mesh. Exact bounds, that is bounds guaranteed with respect to the exact solution, are needed to properly certify the accuracy of the results, especially if the meshes are coarse. The paper introduces a procedure to compute strict upper and lower bounds of the error in linear functional outputs of parabolic problems. In this first part, the bounds account for the error associated with the spatial discretization. The error coming from the time marching scheme is therefore assumed to be negligible in front of the spatial error. The time discretization is performed using the discontinuous Galerkin method, both for the primal and adjoint problems. In the error estimation procedure, equilibrated fluxes at interelement edges are calculated using hybridization techniques.

Bounds of functional outputs for parabolic problems. Part II: Bounds of the exact solution

María Jesús Samper — Mon, 28 Oct 2019 14:33:10 +0100

The paper introduces a methodology to compute upper and lower bounds for linear-functional outputs of the exact solutions of parabolic problems. In this second part, the bounds account for the error both in space and time. The assumption stating that the error introduced by the time marching scheme is negligible, used in the first part, is removed here. The bounds are computed starting from an approximation of the exact solution, associated with a spatial mesh and a time grid. Nevertheless, the bounds are guaranteed with respect to the exact solution, with no reference to any mesh or time discretization.

A stabilized finite element approximation of low speed thermally coupled flows

María Jesús Samper — Tue, 03 Sep 2019 13:28:19 +0200

Purpose – The purpose of this paper is to describe a finite element formulation to approximate thermally coupled flows using both the Boussinesq and the low Mach number models with particular emphasis on the numerical implementation of the algorithm developed.

Design/methodology/approach – The formulation, that allows us to consider convection dominated problems using equal order interpolation for all the valuables of the problem, is based on the subgrid scale concept. The full Newton linearization strategy gives rise to monolithic treatment of the coupling of variables whereas some fixed point schemes permit the segregated treatment of velocity-pressure and temperature. A relaxation scheme based on the Armijo rule has also been developed.

Findings – A full Newtown linearization turns out to be very efficient for steady-state problems and very robust when it is combined with a line search strategy. A segregated treatment of velocity-pressure and temperature happens to be more appropriate for transient problems.

Research limitations/implications – A fractional step scheme, splitting also momentum and continuity equations, could be further analysed.

Practical implications – The results presented in the paper are useful to decide the solution strategy for a given problem.

Originality/value – The numerical implementation of a stabilized finite element approximation of thermally coupled flows is described. The implementation algorithm is developed considering several possibilities for the solution of the discrete nonlinear problem.

Algebraic pressure segregation methods for the incompressible Navier-Stokes equations

María Jesús Samper — Tue, 03 Sep 2019 12:58:42 +0200

This work is an overview of algebraic pressure segregation methods for the incompressible Navier-Stokes equations. These methods can be understood as an inexactLU block factorization of the original system matrix. We have considered a wide set of methods: algebraic pressure correction methods, algebraic velocity correction methods and the Yosida method. Higher order schemes, based on improved factorizations, are also introduced. We have also explained the relationship between these pressure segregation methods and some widely used preconditioners, and we have introduced predictor-corrector methods, one-loop algorithms where nonlinearity and iterations towards the monolithic system are coupled.

Finite element approximation of the modified Boussinesq equations using a stabilized formulation

María Jesús Samper — Tue, 03 Sep 2019 12:44:09 +0200

In this work, we present a finite element model to approximate the modified Boussinesq equations. The objective is to deal with the major problem associated with this system of equations, namely, the need to use stable velocity‐depth interpolations, which can be overcome by the use of a stabilization technique. The one described in this paper is based on the splitting of the unknowns into their finite element component and the remainder, which we call the subgrid scale. We also discuss the treatment of high‐order derivatives of the mathematical model and describe the time integration scheme

Analysis of a stabilized finite element approximation of the Oseen equations using orthogonal subscale

María Jesús Samper — Tue, 03 Sep 2019 12:32:47 +0200

In this paper we present a stabilized finite element formulation to solve the Oseen equations as a model problem involving both convection effects and the incompressibility restriction. The need for stabilization techniques to solve this problem arises because of the restriction in the possible choices for the velocity and pressure spaces dictated by the inf–sup condition, as well as the instabilities encountered when convection is dominant. Both can be overcome by resorting from the standard Galerkin method to a stabilized formulation. The one presented here is based on the subgrid scale concept, in which unresolvable scales of the continuous solution are approximately accounted for. In particular, the approach developed herein is based on the assumption that unresolved subscales are orthogonal to the finite element space. It is shown that this formulation is stable and optimally convergent for an adequate choice of the algorithmic parameters on which the method depends.

Finite element approximation of the hyperbolic wave equation in mixed form

María Jesús Samper — Tue, 03 Sep 2019 12:22:09 +0200

The purpose of this paper is to present a finite element approximation of the scalar hyperbolic wave equation written in mixed form, that is, introducing an auxiliary vector field to transform the problem into a first-order problem in space and time. We explain why the standard Galerkin method is inappropriate to solve this problem, and propose as alternative a stabilized finite element method that can be cast in the variational multiscale framework. The unknown is split into its finite element component and a remainder, referred to as subscale. As original features of our approach, we consider the possibility of letting the subscales to be time dependent and orthogonal to the finite element space. The formulation depends on algorithmic parameters whose expression is proposed from a heuristic Fourier analysis.

Pressure segregation methods based on a discrete pressure Poisson equation. An algebraic approach

María Jesús Samper — Tue, 03 Sep 2019 12:12:48 +0200

In this paper, we introduce some pressure segregation methods obtained from a non‐standard version of the discrete monolithic system, where the continuity equation has been replaced by a pressure Poisson equation obtained at the discrete level. In these methods it is the velocity instead of the pressure the extrapolated unknown. Moreover, predictor–corrector schemes are suggested, again motivated by the new monolithic system. Key implementation aspects are discussed, and a complete stability analysis is performed. We end with a set of numerical examples in order to compare these methods with classical pressure‐correction schemes.

Modeling Precipitate Dissolution in Hardened Aluminium Alloys using Neural Networks

María Jesús Samper — Thu, 25 Jul 2019 13:45:58 +0200

This work presents a neural networks approach for finding the effective activation energy and modeling the dissolution rate of hardening precipitates in aluminium alloys using inverse analysis. As way of illustration, a class of multilayer perceptron extended with independent parameters is applied for that purpose to aluminium alloys AA-7449-T79, AA-2198-T8 and AA-6005A-T6.

Robust design methods in aerospace engineering

María Jesús Samper — Tue, 18 Jun 2019 13:44:50 +0200

This document is an introduction to some important methodologies that have been developed in robust design in aerospace engineering. After describing the concept of robustness and uncertainty, multipoint, minimax, expected value, second order second moment and Taguchi methods are mentioned. At the end of this report, Game Theory, as one of the approach for multi objective optimization problems has been introduced.

Implementation of a general algorithm for incompressible and compressible flows within the multi-physics code Kratos and preparation of fluid-structure coupling

María Jesús Samper — Tue, 18 Jun 2019 13:39:12 +0200

This diploma thesis deals with the implementation of a fluid solver for incompressible and compressible flows within the multi-physics framework Kratos. The presentation of this environment based on the finite element method (FEM) and an introduction to multidisciplinary problems in general are the starting point of this work and help understanding the following steps more easily.

Originating from the basic conservation equations for mass, momentum and energy, the Euler equations for inviscid flow are derived. In this context some approximations are presented that avoid the solution of the energy equation and allow the use of a general approach for the simulation of incompressible, slightly compressible and barotropic flow. The implementation of the incompressible case is outlined step-by-step: Having discretized the continuous problem, a fractional step scheme is presented in order to uncouple pressure and velocity components by a split of the momentum equation. Emphasis is placed on the nodal implementation using an edge-based data structure. Moreover, the orthogonal subscale stabilization - necessary because of the finite element discretization - is explained very briefly.

Subsequently, the solver is extended to compressible regime mentioning the respective modifications. For validation purposes numerical examples of incompressible and compressible flows in two and three dimensions round of this first part.

In a second step, the implemented flow solver is prepared for the fluid-structure coupling. After presenting solving procedures for multi-disciplinary problems, the arbitrary Lagrangian Eulerian (ALE) formulation is introduced and the conservation equations are modified accordingly. Some preliminary tests are performed, particularly with regard to mesh motion and adjustment of the boundary conditions. Finally, expectations for the envisaged fluid-structure coupling are brought forward.

PUMI: An explicit ED unstructural finite element solver for the Euler equations

María Jesús Samper — Tue, 18 Jun 2019 13:27:45 +0200

The PUMI flow solver has been developed at CIMNE in to address the need for fast solutions of the flow field around complex geometries. Nowadays calculations involving a number of cells on the order of ten million are performed routinely. PUMI was created to deal with this kind of large-scale problem using modest hardware, therefore special emphasis was placed on the computational efficiency of the code. Design guidelines where minimum memory requirement, very fast single-threaded performance as well as satisfactory parallel scaling up to a moderate number of threads (as found on current desktop hardware using a small number of multi-core CPUs. In order to speedup the mesh generation activities an unstructured finite element formulation was selected. This papers describes the theoretical basis of the algorithms as well as detail of the implementation that increase the robustness and efficiency of the code.

A cooling system for a hybrid PV/thermal linear concentrator

María Jesús Samper — Tue, 18 Jun 2019 13:17:32 +0200

This paper presents the thermal evaluation of an evacuated PVT collector designed to operate under concentrated radiation (15 suns). Finite volume 3D numerical computations have been carried out in order to study the thermal characteristics of different rectangular cross section aluminium pipes and to test the performance of the PVT collector with several laminar flow rates. Experiments with the same laminar flows show the same behavior than in the numerical results.

A finite point method for adaptive three-dimensional compressible flow calculation

María Jesús Samper — Tue, 18 Jun 2019 13:07:11 +0200

The Finite Point Method (FPM) is a meshless technique which is based on both, a Weighted Least-Squares numerical approximation on local clouds of points and a collocation technique which allows obtaining the discrete system of equations. The research work we present is part of a major investigation into the capabilities of the FPM to deal with threedimensional applications concerning real compressible fluid flow problems. In the first part of this work, the upwind biased scheme employed for solving the flow equations is described. Secondly, with the aim of exploiting meshless capabilities, an h-adaptive methodology for two and three-dimensional compressible flow calculations is developed. This adaptive technique applies a solution-based indicator in order to identify local clouds where new points should be inserted in or existing points could be safely removed from the computational domain. The flow solver and the adaptive procedure have been evaluated and the results are highly encouraging. Several numerical examples are provided throughout the article in order to illustrate their performance.

Lift maximization with uncertainties for high lift devices optimization

María Jesús Samper — Tue, 18 Jun 2019 13:01:07 +0200

In this paper, the aerodynamic shape optimization problems with uncertain operating conditions has been addressed. After a review of robust control theory and the possible approaches to take into account uncertainties, the use of Taguchi robust design methods in order to overcome single point design problems in Aerodynamics is proposed. Under the Taguchi concept, a design with uncertainties is converted into an optimization problem with two objectives which are the mean performance and its variance, so that the solutions are as less sensitive to the uncertainty of the input parameters as possible. Furthermore, the Multi-Criterion Evolutionary Algorithms (MCEAs) are used to capture a set of compromised solutions (Pareto front) between these two objectives. The flow field is analyzed by Navier-Stokes computation using an unstructured mesh. The proposed approach drives to the solution of a multi-objective optimization problem that is solved using a modification of a Nondominated Sorting Genetic Algorithm (NSGA). In order to reduce the number of expensive evaluations of the fitness function a Response Surface Modeling (RSM) is employed to estimate the fitness value using the polynomial approximation model. During the solution of the optimization problem a Semi-torsional Spring Analogy is used for the adaption of the computational mesh to all the obtained geometrical configurations. The proposed approach is applied to the robust optimization of the 2D high lift devices of a business aircraft by maximizing the mean and minimizing the variance of the lift coefficients with uncertain free-stream angle of attack at landing and takeoff flight conditions, respectively.

Validación experimental del Particle Finite Element Method (PFEM)

María Jesús Samper — Tue, 18 Jun 2019 12:50:39 +0200

Desarrollo de un soporte metálico intravascular

María Jesús Samper — Tue, 18 Jun 2019 12:41:13 +0200

Las enfermedades cardiovasculares son la primera causa de muerte de la población Europea. Se estima que la mortalidad por enfermedades cardiovasculares es la mitad de la mortalidad total en toda Europa y provoca 4,35 millones de fallecidos cada año en los 52 estados miembros de la Región Europea. Según la Organización Mundial de la Sanidad (OMS) más de 1,9 millones de muertos en la Unión Europea, además de ser la principal causa de deshabilitad y reducción de calidad de vida.

Estos tipos de enfermedades afectan sobre todo a la mayor parte de la población, y, sabiendo que el porcentaje de ancianos en la nuestra sociedad sigue subiendo, se puede fácilmente entender que las cardio-patologías puedan constituir siempre un riesgo elevado para la salud de los países occidentales.

La cirugía moderna busca cada día soluciones menos invasivas, como por ejemplo a través de cirugía llamada mini-invasiva.

La cirugía mini-invasiva es la técnica quirúrgica que consiente acceder a cavidades internas sin operar incisiones (cirugía en abierto). En esta definición, es trivial intuir que entran sobre todo las técnicas endoscópicas que han permitido realizar muchas operaciones de diferente grado de peligrosidad produciendo numerosos beneficios y reduciendo los índices de riesgo.

En la cirugía cardiovascular no es raro encontrar problemáticas de tener que insertar aparatos como stent, válvulas cardiacas, sondas y muchas cosas más a través pequeños orificios (como vasos sanguíneos, por ejemplo, la femoral, la aorta la carótida o la subclavia). Estos aparatos van a ser posicionados o conducidos a través de guías (catéteres) que los conducen hasta el sitio destinado. El hecho de utilizar catéteres que tienen que penetrar por estas vías obliga a que estos aparatos respecten dimensiones muy pequeñas.

Es interesante entonces estudiar como estas estructuras deben de soportar esfuerzos de compresión y de expansión cuando vienen insertadas en el catéter y luego se sueltan.

El ejemplo en el cual enfocaremos nuestro estudio va a ser un soporte metálico intravascular para cualquier aparato necesite ser anclado en el interior de una vena o arteria.

Numerical validation of hemodynamic factors in vascular diseases

María Jesús Samper — Tue, 18 Jun 2019 12:32:34 +0200

Desarrollo de modelos constitutivos avanzados para análisis del comportamiento no lineal de materiales de construcción

María Jesús Samper — Tue, 18 Jun 2019 12:23:57 +0200

En este informe se describen algunos de los desarrollos recientes en modelos constitutivos avanzados para el comportamiento no lineal de materiales de construcción. El trabajo se centra especialmente en los modelos de simulación numérica del fenómeno de fisuración en hormigón estructural y otros geomateriales tales como la mampostería y la obra de fábrica. En la primera parte del informe se describen los enfoques principales para la simulación numérica de la fisuración a tracción en estructuras de hormigón: el de fisura discreta y el de fisura distribuida, para centrarse en el segundo. Dentro de éste, el informe describe en detalle un modelo escalar de daño continuo desarrollado en CIMNE. Este modelo de daño se basa en la partición del tensor de tensiones para poder capturar el comportamiento unilateral del hormigón al pasar de tracción a compresión y viceversa. El modelo propuesto adopta un formalismo basado en las deformaciones totales, lo cual aumenta su eficiencia algorítmica y lo hace especialmente apto para aplicaciones sísmicas y problemas de gran tamaño, tal como se muestra en las aplicaciones presentadas. En la última parte del informe se trata el tema de la localización de deformaciones y de daño y de la simulación numérica del colapso estructural. En esta parte se combina el modelo de daño distribuido presentado anteriormente con un algoritmo de rastreo de fisuras. La mejoría de las capacidades del modelo se hace patente en las aplicaciones mostradas y, especialmente, en el estudio de un arco semicircular de obra de fábrica con carga asimétrica, cuyos resultados son

mucho más realistas que los que se obtienen con el modelo de daño distribuido en su

forma original. El informe concluye con algunas observaciones sobre la utilidad de los

modelos constitutivos avanzados y su aplicación por parte de los usuarios finales de

programas comerciales o de propósito específico.

Development and characterization of semitransparent double skin PV façades

María Jesús Samper — Tue, 18 Jun 2019 12:12:54 +0200

This research aims at developing new standardized typologies of semitransparent double skin façades formed by PV laminates in the outer skin. At present there are many buildings in Europe which incorporate such active façades, but all have been designed as user defined projects and very few accurately evaluate the feasibility of using the heat produced within the air gap. There is actually a lack of effective methodology to allow non-specialist architects to design and evaluate such façades. This research tries to address this situation: the Spanish PV manufacturer ISOFOTON, together with the partners of the PVTBUILDING project: CIMNE, the UdL, PICHAguilera, DOMUS and BSC have begun a collaboration to design industrialized modules constituted by an external semitransparent PV layer, a wide air gap and an internal glass layer.

This paper describes the results of four stages of a more wide research: a detailed analysis of the existing double skin façades in office buildings and the definition of a family of standard PV modules and ventilated façades; an intensive evaluation of the existing heat transfer relations for asymmetrical heated vertical air channels; the programming of a dynamic transient solver based on TRNSYS and the validation of the codes with the set up of prototypes and the beginning of an experimental campaign.

Análisis elasto-viscoplástico en problemas bidimensionales con Stampack

María Jesús Samper — Tue, 18 Jun 2019 11:54:24 +0200

Este informe presenta los avances logrados en la implementación dentro del código Stampack, de un modelo constitutivo elasto-viscoplástico del tipo de Perzyna para materiales isótropos con endurecimiento por deformación. El objetivo principal de incluir un modelo elasto-viscoplástico en Stampack, es la posibilidad de tener en cuenta como influye la velocidad de deformación en problemas industriales como el forjado o la extrusión. En estos problemas las temperaturas elevadas (más de un tercio de la temperatura de fusión) juegan un rol importante, provocando un estado viscoso en el material de manera que el flujo plástico resulta ser función de la velocidad de deformación del sólido.

El modelo elegido resulta una extrapolación directa del modelo elasto-plástico basado en el gradiente de deformaciones propuesto por Garino [1]. El modelo elasto-visco-plástico unificado se corresponde al propuesto por Ponthot [2]. Aquí se ha empleado el trabajo de Garino y Ponthot et al.[3] para la definición de un benchmark aceptable para la comparación de resultados. En este informe se presenta el modelo elasto-viscoplástico implementado en el código de elementos finitos Stampack, y se muestra la primera etapa de prueba asociada con problemas en pequeñas deformaciones. Anteriormente Stampack no poseía un modelo elasto-viscoplástico para tratar problemas bidimensionales en deformaciones finitas.

El contenido del informe es el siguiente: la sección 2 presenta la cinemática asociada al modelo, el modelo de endurecimiento viscoso y el esquema numérico de integración de la ecuación constitutiva. La sección 3 muestra el ingreso de datos a Stampack y cuáles son las rutinas involucradas en proceso de integración del modelo elasto-viscoplástico. Por último, la sección 4 contiene un problema de aplicación y se comparan los resultados del presente trabajo con los obtenidos por otros investigadores.

Nuevos elementos de lámina cusdrilateros sin rotaciones

María Jesús Samper — Tue, 18 Jun 2019 11:38:43 +0200

El contenido de este informe semestral es el siguiente. En la Sección 3 se presentan los aspectos básicos de la formulación original del elemento BSQ. Se muestra la geometría donde se define “la parcela de elementos” y el sistema de coordenadas a utilizar y el cálculo de las curvaturas en función de las coordenadas de los nudos de la parcela. En la Sección 4 se describe una forma alternativa de tratar el campo de curvatura con motivos de extender las capacidades del BSQ al tratamiento de superficies quebradas y ramificadas. El cálculo de las deformaciones membranales se muestra en la Sección 5. En la Sección 6 se muestra el nuevo esquema particular de estabilización física y una forma alternativa de tratar las fuerzas de estabilización flexional. También se dan algunos detalles respecto al cálculo de fuerzas nodales equivalentes. En la Sección 7 se presenta algunos ejemplos de los elementos presentado incluyendo ejemplos no lineales. Finalmente se resumen algunas conclusiones.

Lift maximization with uncertainties for the optimization of high‐lift devices

María Jesús Samper — Tue, 18 Jun 2019 11:05:27 +0200

In this paper, the aerodynamic shape optimization problems with uncertain operating conditions have been addressed. After a review of robust control theory and the possible approaches to take into account uncertainties, the use of Taguchi robust design methods in order to overcome single point design problems in aerodynamics is proposed. Under the Taguchi concept, a design with uncertainties is converted into an optimization problem with two objectives which are the mean performance and its variance, so that the solutions are as less sensitive to the uncertainty of the input parameters as possible. Furthermore, the modified non‐dominated sorting genetic algorithms are used to capture a set of compromised solutions (Pareto front) between these two objectives. The flow field is analyzed by Navier–Stokes computation using an unstructured mesh. In order to reduce the number of expensive evaluations of the fitness function a response surface modeling is employed to estimate the fitness value using the polynomial approximation model. During the solution of the optimization problem, a semi‐torsional spring analogy is used for the adaption of the computational mesh to all the obtained geometrical configurations. The proposed approach is applied to the robust optimization of the 2D high‐lift devices of a business aircraft by maximizing the mean and minimizing the variance of the lift coefficients with uncertain free‐stream angle of attack at landing flight condition.

Simulation of structural response to violent-free surface flows

María Jesús Samper — Wed, 29 May 2019 14:14:42 +0200

High sea states, waves breaking near shores andmoving ships, the interaction of extremewaveswith floating structures, green water on deck and sloshing (e.g. in liquid natural gas (LNG) tankers) are but a few examples of flows with violent free surface motion. The bodies exposed to these flows experience large, time-varying forces that can lead to fatigue and/or failure. It is therefore imperative to have a predictive capability in order to guarantee operability and optimize the lifespan under these conditions.

An extended class of multilayer perceptron

María Jesús Samper — Fri, 26 Apr 2019 10:54:56 +0200

In this work an extended class of multilayer perceptron is presented. This includes independent parameters, boundary conditions and lower and upper bounds. In some cases, such extensions contain a priori information of the problem. On some other situations they are necessary in order to define a correct representation for the solution.

The use of this augmented class of neural network is illustrated through a case study in the optimal control theory. The numerical results are compared against the analytical solution.

Information in companies as a tool to innovate and compete

Scipedia content — Mon, 08 Apr 2019 12:07:44 +0200

Although innovation is a key factor for the survival of enterprises, its situation in Spain is still far from the objectives set by the Lisbon Strategy. As a consequence the Spanish public administrations have launched various measures to improve it. Innovation requires acquiring and selecting the best information available, which means mainly using scientific and technical databases, but they are little known in the business environment. The article gives a brief overview of the use of information for innovation in enterprises and comments on the main findings of 2008 Cotec Report

About the Network Society

Scipedia content — Mon, 08 Apr 2019 11:40:30 +0200

Chronicle of the course “Network society: social changes, organizations and citizens” (Barcelona, October 2008). The topics covered were the state of development on the Network society, organizations, citizenry, communication and innovation.

Networks, scientific publication and innovation at the LIS-EPI Meeting

Scipedia content — Mon, 08 Apr 2019 11:40:22 +0200

Report on the 3rd International LIS-EPI Meeting 2008 which was held in Valencia, organized by the Universidad Politécnica de Valencia (UPV), Profesional de la Información (EPI) and the Innovation department of the Universitat Oberta de Catalunya (UOC). The topics covered were the knowledg

Mark Zuckerberg, founder of Facebook, at the Universidad de Navarra

Scipedia content — Mon, 08 Apr 2019 11:40:14 +0200

With more than a hundred million users, Facebook is one of the largest social networks in internet. For its promotion in Europe its founder, Mark Zuckerberg, made a tour of various countries. In this context, we offer a chronicle of the conference held at the University of Navarra in October 2008. During the conference, Zuckerberg talked about the history of Facebook and its main innovations, such as the news feed or its interoperability with other applications. The question and answer session included discussion of censorship of content by Facebook, the new interface, and competition with other social networks.

Free online games, open source software and library technical roles, what do they have in common?

Scipedia content — Mon, 08 Apr 2019 11:40:06 +0200

Consumers are coming to expect a more flexible approach to purchasing software applications, with upgrades and add-ons being available as downloads rather than physically going to a shop to make their purchase. This shift in thinking is filtering its way into the library and information field with open source software, available for download online and with its own online community becoming more of a serious consideration than ever before. This calls for staff with a library background to also have technical skills and be savvy, installing, testing and rolling these open source additions to working life.

Asia seen through the SCImago Journal & Country Rank (SJR)

Scipedia content — Mon, 08 Apr 2019 11:39:59 +0200

Application of the SCImago Journal & Country Rank (SJR), based on the database Scopus, of Elsevier, to analyze the scientific output of the major Asian countries and their global impact, measured by the number of citations received. It can be observed a production increase of the Republic of Korea, India and especially China

Facebook as a network of librarians, information scientists and archivists in Latin America

Scipedia content — Mon, 08 Apr 2019 11:39:52 +0200

Results of a qualitative-quantitative analysis of the use that professionals and organizations related to librarianship, documentation and archives in Latin America are making of Facebook are compared with other social networking platforms. More than a tool for interacting with friends and family, it is suitable for creating community and establishing business and labor contacts. The analysis confirms the cultural and technological trend of people increasingly seeking “convergence”, defined as the ability to adapt and use a technological tool for a variety of purposes, using Facebook both as a means of social interaction (friends, relatives, fellow students, etc.) and for professional and labor interactions, thus taking on different roles.

Introduction to network analysis

Scipedia content — Mon, 08 Apr 2019 11:39:43 +0200

Despite its long existence and international acceptance, network theory and analysis is a practically unknown approach in Documentation, both theoretically and methodologically speaking. Fortunately, this trend is changing, inasmuch as network theory and analysis may mean a quantitative and qualitative leap forward in the representation and analysis of the structure of all types of scientific domains, whether geographic, thematic or institutional. The extraordinary advances that have taken place in recent years in the study and analysis of complex networks have been made possible by a number of parallel developments. First of all, with computerized data acquisition and handling, large databases can be managed, leading to the emergence of different real network topologies. Secondly, the increase in computing power has made it possible to explore networks with millions of nodes. Thirdly, there is the slow but sure breakdown of boundaries between disciplines. This can be seen by researchers because of their ability to access and use databases that facilitate an understanding of the generic properties of complex networks.

Networks in digital libraries, a personal view

Scipedia content — Mon, 08 Apr 2019 11:39:35 +0200

This is a personal introduction to the relationship between digital libraries and networks. I recall the way I came to the subject of networks. I describe the way that I have tried to harness networks for digital library building. And I point out some of the difficulties in networking digital objects and their descriptions in digital libraries.

The Universidad Carlos III campus in Second Life

Scipedia content — Mon, 08 Apr 2019 11:39:27 +0200

Second Life is a three-dimensional virtual environment that many consider merely a game but it has enormous possibilities for elearning and communication. There are academic libraries that are trying to take advantage of it; the Universidad Carlos III Library is one of them. This paper presents its project, with which it expects to anticipate that which very probably will be the future way of displaying information on the internet: 3D web.

Employment survey of Universidad de Zaragoza graduates in Information Science studies (1992-2006)

Scipedia content — Mon, 08 Apr 2019 11:39:19 +0200

The article presents the results of a survey on working life, answered by 183 graduates in Information Science studies of the Universidad de Zaragoza, between the years 1992 and 2006. The results can be summarized in that these professionals improve their academic results with respect to other previous studies due to their motivation throughout the studies. The expectations for job access of these graduates have been fulfilled in most of the cases, and they spent an average of thirteen months looking for a job. A great part of these workers are employed in specific functions of Information Science. Nevertheless, most of them don’t belong to any Professional Association of Information Sciences. In spite of this, we can conclude that these studies must be better known in order to show everybody what opportunities are available to these professionals.

Co-term and social networks analysis for the generation of subject maps

Scipedia content — Mon, 08 Apr 2019 11:39:10 +0200

Improvement of the interfaces and search capacities of the opacs continues to be one of the main challenges for libraries, especially with regard to searching by subject. The visual interfaces can help with retrieval. This paper explores the combination of co-term analysis techniques with social networks for the generation of subject maps of collections. The main conclusion is that the methodology applied is valid, and that the maps could be used for browsing and subject retrieval. It would also be useful for improving the quality of indexing.

Social evolution and networking in the Library and Information Science community

Scipedia content — Mon, 08 Apr 2019 11:39:00 +0200

Our society is increasingly interconnected through multiple types of networks, and humankind is changing their habits accordingly, adapting to the use of new technologies. We explore the psycho-social characteristics that determine people’s behavior through the communication channels. We discuss some structures of networking in the field of Library and Information Science: mailing lists, directories, etc. We conclude that the work of the information professional fits perfectly in the current wave 2.0 of information sharing.

Animating the development of Social networks over time using a dynamic extension of multidimensional scaling

Scipedia content — Mon, 08 Apr 2019 11:38:51 +0200

The animation of network visualizations poses technical and theoretical challenges. Rather stable patterns are required before the mental map enables a user to make inferences over time. In order to enhance stability, we developed an extension of stress minimization with developments over time. This dynamic layouter is no longer based on linear interpolation between independent static visualizations, but change over time is used as a parameter in the optimization. Because of our focus on structural change versus stability the attention is shifted from the relational graph to the latent eigenvectors of matrices. The approach is illustrated with animations for the journal citation environments of Social networks, the (co)author networks in the carrying community of this journal, and the topical development using relations among its title words. Our results are also compared with animations based on PajekToSVGAnim and SoNIA.

Structural analysis of an online social network: the Spanish network of Flickr

Scipedia content — Mon, 08 Apr 2019 11:38:38 +0200

This paper intends, from a structural point of view, to analyse the network of Flickr’s members who live or were born in Spain. The aim of the study is to know how the network evolves, what is its shape, what groups are detected and what uses are carried out within the network. We identified 663 Flickr members through a double snowball process and harvested their joining date, photos and contacts with a crawler. The results show that the users who joined Flickr in 2004 use the service as a communication medium among amateur photographers, while the subsequent members utilise Flickr as a real social network, using the photos as a way to express personal experiences, opinions and tastes.

Academic libraries and Facebook: how and why we should be there

Scipedia content — Mon, 08 Apr 2019 11:38:29 +0200

Over the past year, the popularity of social networking sites has seen tremendous -growth in Spain. Because of these networks’ everyday online ubiquity, the rising number of new users, and the integration of library applications, information professionals have taken a huge interest in social networking sites. This article analyzes the concept behind social networking sites, different types of these sites, the use of Facebook as an academic library, and the creation of Facebook pages as the best presence model for libraries. The final part of the article discusses how to create and promote a Facebook page and how to organize events on the web site.

Social networks: organizational models or digital services?

Scipedia content — Mon, 08 Apr 2019 11:38:19 +0200

We are social beings and we have been creating networks since our inception. The network represents a new paradigm for social and economic development that has been called the “Network Society”. People who use digital tools intensively are fragmenting their identity into multiple local and global networks. The social network services are a simplification and a restriction of the variety of social interactions. The combination of various Web 2.0 tools seems more interesting than the Facebook model.

Directory publishers looking over the fence

Scipedia content — Mon, 08 Apr 2019 11:38:11 +0200

Report on the European Association of Directory and Database Publishers (EADP) spring conference held in Barcelona, 8-9 May 2008. This European professional organisation of yellow page and business directory publishers is increasingly becoming a database publishers organisation. Its members realize that although they still are strong at the local level, they have to evolve from paper to new electronic products in order to compete with global search engines.

Online information conference 2007

Scipedia content — Mon, 08 Apr 2019 11:38:02 +0200

Report of the main concepts and comments heard at the 31st Online Information Conference (formerly Online Information Meeting) in London, organized by Incisive Media - VNU Exhibitions. Topics covered: Web 2.0 influence in libraries, behaviour of young people as users of information services, the Wikipedia phenomenon, the evolution of knowledge management. There is also a report of the Spanish Meeting Point, a stand that served as a platform for small businesses, professionals and academics from Spain

20 años de Doc6. Entrevista a Adela d’Alòs-Moner

Scipedia content — Mon, 08 Apr 2019 11:37:54 +0200

Adela d’Alòs-Moner, socia fundadora de Doc6, tiene una gran experiencia profesional ejerciendo tanto en centros públicos como privados: entre otros cargos fue directora de la biblioteca de Ciencias de la Universidad Autónoma de Barcelona y directora del Centro de documentación central y coordinadora de los proyectos internet y de la intranet del Ayuntamiento de Barcelona. Ha impartido clases en la Universidad Carlos III de Madrid, Universitat de Barcelona, Universitat Oberta de Catalunya, ICT, escuela de negocios EOI... Fue presidenta del Col.legi de Bibliotecaris- Documentalistes de Catalunya.Doc6 celebra en 2008 su 20 aniversario y veinte años son muchos para una pyme. Bibliotecarios, documentalistas y profesionales de la información la crearon en 1988. En la actualidad tiene oficinas en Barcelona y en Madrid y cuenta con más de 110 empleados, el 85% de los cuales son diplomados o licenciados superiores en documentación o informática.

Thomson Scientific’s web-based bibliometric complements: good and nice and free

Scipedia content — Mon, 08 Apr 2019 11:37:45 +0200

The wide variety of bibliometric information resources offered for free by Thomson Scientific’s ScienceWatch. com are presented, and their major applications within scientific libraries are described.

Web genres: research trends

Scipedia content — Mon, 08 Apr 2019 11:37:36 +0200

We present a review of some of the main trends of research into web genres. Genres are documents defined primarily by the communicative purpose they accomplish for their producers and recipients, though they also present specific characteristics of topic and form. Thinking of web documents in terms of genres provides a selection criterion which is complementary to topic or subject, and which can also be implemented in automatic classifiers. The review offers a definition of web genres, a summary of achievements in automatic classification of web genres, and a perspective from which to sort out the increasing number of contributions on genres.

Esade Guíame!: starting point of the wellinformed company

Scipedia content — Mon, 08 Apr 2019 11:37:25 +0200

The Esade Guíame! business and sector-specific information portal is presented. This portal aims to inform and educate the business community and academia on how to identify and obtain economic and sector-specific information, a vital part of decision-making. A description of the portal’s mission and objectives is provided, along with its target audience, value, origins, evolution and main contents. Also included are its main challenges for the future and an analysis of its value chain, based on a combination of personnel, processes and design.

Business information systems in companies

Scipedia content — Mon, 08 Apr 2019 11:37:17 +0200

In 2002 the Department of Innovation and Economic Promotion of the Provincial Council of Bizkaia set up the Zaintek Strategic Competitive Surveillance service to increase awareness among SMEs in Bizkaia concerning the use of information as a tool for strategic management. To that purpose, Zaintek has focused on awareness and on developing a number of increasingly complex support services via its website. One of the most highly-developed services is a business information system (BIS) tailored to SMEs. This article examines the prerequisites for the implementation of this service, its objectives and its stages of development. Three years ago Zaintek was integrated into BAI (the Bizkaia Innovation Agency), evidencing the importance attributed by the public administration to surveillance as a support tool at all levels of innovation.

The revolution of mass media on the internet. The case of the economic content

Scipedia content — Mon, 08 Apr 2019 11:37:09 +0200

The electronic newspaper concept undergoes a permanent metamorphosis caused by the continuing transformation of the information structure in the digital environment. The new public audience for cyberjournalism demands updated and hypersegmented content based on collective participation. Economic information is an example that shows both processes, which can be seen with the success and popularity of the platforms for news distribution. This article aims to help understand the change produced since 2007 and tries to describe the scene in which cybermedia will have to compete, assuming new coordinates in the media universe of the internet

Peer-to-peer architectures applied to the distribution of audiovisual archives

Scipedia content — Mon, 08 Apr 2019 11:37:01 +0200

The distribution of large audiovisual archives through electronic networks has problems like the lack of scalability and an excessive cost. To deal with these obstacles, some institutions and broadcasters are applying peer-to-peer architectures in order to optimize the transmission and to reduce its cost. This article explains this model and its main characteristics, as well as some of the projects which are using it nowadays. It analyses the advantages associated to this system and the contribution it can make for a more efficient distribution of archives. The aim is to make the audiovisual heritage available to a citizenry educated in a culture of images and sound

A semantic service model of selective dissemination of information (SDI) for digital libraries

Scipedia content — Mon, 08 Apr 2019 11:36:52 +0200

We present the theoretical and methodological foundations for the development of a multi-agent SDI service model for specialized digital libraries, applying semantic web technologies that permit more efficient information management, improving agent-user communication processes and facilitating accurate access to relevant resources. To do this, rss feeds are used as “current awareness bulletins” to generate personalized bibliographic alerts. The SDI service model has an rss feeds management module and an information push module. In the first module, resources are represented as rss feed items and are also semi-automatically assigned subject terms by matching their associated keywords against the terms of a SKOS Core format thesaurus. In the information push module, bibliographic alerts are customized according to the preferences defined on users’ profiles.

Presence of the Spanish digital press on the social Web: analysis of Menéame

Scipedia content — Mon, 08 Apr 2019 11:36:44 +0200

The objective of our study is to measure the visibility of the Spanish press in Menéame, the most important social content manager in Spanish, during 2007 and the first quarter of 2008. To this end, the number of news items published in Menéame is counted and averaged with votes and comments received, focusing on the evolution of the five media with a greater presence; finally, the obtained ranking is contrasted with that of OJD Interactiva. The most represented newspaper is El País, followed at a certain distance by El Mundo and 20minutos and, farther behind, La Vanguardia and El Periódico de Catalunya.

Methodology for the implementation of an external corporate blog

Scipedia content — Mon, 08 Apr 2019 11:36:36 +0200

A methodology to implement a corporate external blog is proposed. Firstly, there is an introduction to the new models of organizational communication with customers and users, resulting from the acceptance of new technologies in society and the development of Web 2.0. Secondly, it delves into the blog concept and the benefits that this type of tools can afford within the corporate realm, along with their types and functions, to finally propose a methodology for successful corporate implementation of an external blog.

Enterprise strategy and information technologies in technical-documentary knowledge management. The case study of Nuclenor

Scipedia content — Mon, 08 Apr 2019 11:36:26 +0200

The experience and results of the development and implementation of a technical-documentary information management system in the enterprise Nuclenor (Power plant of Santa María of Garoña) are presented. In order to share knowledge and contribute as far as possible to the dissemination of this kind of systems in other enterprises and organizations, we explain the organizational strategy and objectives defined by Nuclenor to carry out this project, and analyze the functional requirements of the system. From a technical perspective the development methodology used and the support technological model of the system is presented. Finally, we review the results and benefits of the project for the enterprise, and comment the research lines currently open.

Dos anuarios imprescindibles y complementarios: Anuario de Bibliotecas Españolas 2008 y Anuario ThinkEPI 2008

Scipedia content — Mon, 08 Apr 2019 11:36:18 +0200

Archivos y derechos humanos (Ramon Alberch Fugueras)

Scipedia content — Mon, 08 Apr 2019 11:36:11 +0200

RAMÓN

Seminario sobre imprenta y librería en 2010

Scipedia content — Mon, 08 Apr 2019 11:36:03 +0200

New techniques of scientific publication. Third Medes-Lilly workshop

Scipedia content — Mon, 08 Apr 2019 11:35:53 +0200

The proliferation of new communication technologies and the numerous websites that provide health information are a source of unimaginable new possibilities for improving health information and care due to their interactivity, ability to customize relationships with users, and ease of content publishing and updates. However, the particular sensitivity of health information for the health and lives of individuals may pose risks that must be foreseen and curbed. In its third edition, the Jornada Medes analyzes the evolution of the dissemination of scientific knowledge through new technologies. The meeting addressed the process of transforming the printed journal to the electronic one and the various ways in which this process happens. How new technologies are applied to complex editorial processess, and the respective advantages and disadvantages, were examined.

OpenOffice and OpenDocument format: functions and compatibility

Scipedia content — Mon, 08 Apr 2019 11:35:42 +0200

Presentation of the OpenOffice suite and the ODF format. The basic characteristics of OpenOffice and ODF format are presented. The need for the adoption of opensource software and open formats is discussed. Finally, an ODF case study of converting xhtml documents related to an e-learning course is presented.

Luis Collado, director of Google Books España

Scipedia content — Mon, 08 Apr 2019 11:35:28 +0200

Luis Collado answers some questions about the program Google Book Search. He describes what it is and what it is not. His words reveal Google’s philosophy of universal access to information.

Popularity measurements of Cuban higher education: a webmetric analysis

Scipedia content — Mon, 08 Apr 2019 11:35:16 +0200

We discuss the popularity of Cuba’s MES (Ministry of Higher Education) centres, as well as their interconnectedness and visibility on the world wide web. The role of links in the positioning and visibility of these sites was studied because web browsers use link analysis (or hypertext analysis) to infer not only the content but the quality or the possible “authority” status of a web site. A webmetric study of the 17 centres with web sites was conducted. The relationship between the number of links and page traffic of the MES centres was determined by analysis of the browsers Google, Alltheweb, and Altavista, and also from the Internet Archive and Traffic Rank (Alexa ranking). Four results were obtained: i) the MES centres had better visibility in the browser Altavista, with a Standard Error (SE) ±0,00210; of these, a significantly better value was observed for the 13th centre (superscript a); ii) as page storage in the Internet archive increased, more links or cites were received from the browsers; iii) the links and ranking in Alltheweb showed significantly better performance (SE ± 0,23) and a coefficient of determination (R2) of 0,44%; iv) significant differences exist among MES centre sites in the Internet archive, with respect to links and activity reported in the Traffic Rank.

Personalised news services: user study of Avui.cat newspaper readers

Scipedia content — Mon, 08 Apr 2019 11:35:07 +0200

User studies permit online media to ask users various questions directly, in this case about the benefits to them of personalised news services. The satisfaction survey of Avui.cat readers has revealed how personalised services enhance and increase interest in news information and dedication to reading news, buying the newspaper, or subscribing to other news services.

Library and Information Sciences university education figures in Spain: 2006

Scipedia content — Mon, 08 Apr 2019 11:34:58 +0200

A picture is presented of the state of library and information science university education in Spain. Statistical data is provided about both the number and type of university programs, describing existing institutions, degree levels and providing data on student enrolment and teachers.

Digital collections in Spain: Current situation and future perspectives

Scipedia content — Mon, 08 Apr 2019 11:34:50 +0200

Spain’s national agency for library coordination (Dirección General del Libro, Archivos y Bibliotecas, Subdirección General de Coordinación Bibliotecaria) has launched a series of initiatives to disseminate and preserve the national bibliographic heritage. The digitization of collections and their internet distribution (using well-known standards such as DC, OAI-PMH,OAIS, Premis, SRU/SW) is their most recent project. In addition to all the benefits this brings, their efforts to build consensus for the project is especially appreciated. Of particular significance, they have secured the cooperation of Spain’s autonomous communities (i. e., regional governments), all of their initiatives incorporate technology and procedures compliant with the action Digital Libraries of the EU’s VII Framework Programme.

The publishing industry confronts ebooks

Scipedia content — Mon, 08 Apr 2019 11:34:41 +0200

Books, reading and the publishing industry are experiencing changes motivated by technological advancement. The content has been separated from the material and, therefore, the publishing industry has had to alter its logistic structure, based on physical distribution until recently. Print on demand and online bookstores are now meeting new needs: they have increased the possibilities of visibility and circulation of editorial production, and they have suppressed geographic and physical barriers.

About e-books

Scipedia content — Mon, 08 Apr 2019 11:34:33 +0200

The author comments on some aspects of electronic books: ergonomics, market models, languages, etc., which explain why there is still time for e-books to reach a wide acceptance.

Factores clave en el proceso de adquisición de libros electrónicos

Scipedia content — Mon, 08 Apr 2019 11:34:25 +0200

After the introduction of electronic journals collections in academic libraries the next step is to expand the existing collections of books and reference materials with new content in digital format. The international publishing industry is currently offering their books in digital format. The present article reviews the key factors to be considered in the selection and acquisition stages of electronic books as well as the existing international publishing offer. It is shown also a comparison of electronic books aggregators with strong presence in Spain.

Daisy: an open, multimodal and accessible digital book

Scipedia content — Mon, 08 Apr 2019 11:34:17 +0200

Introduction of the Daisy multimedia book format, which integrates text, sound, images and video in a synchronized sequence. Daisy presents a high usability for digital reading thanks to its advanced navigation through text or audio. The article also describes DTBook, the text component of Daisy, which is a highly structured xml format ideal to create alternate format editions. The article sets out the differences between Daisy and other audiobooks and presents the most common Daisy players and Daisy market adoption. The format has good potential for becoming a flagship format in ebook publishing if costs of playing devices decrease and a solution is found for digital rights management.

Electronic document readers

Scipedia content — Mon, 08 Apr 2019 11:34:08 +0200

This is both a historical overview of reader devices of electronic documents and a description of the current technology characterized by the so called “electronic paper”. Gyricon technologies are analysed as well as the electrophoretic screens and devices that use the electrowetting principle. A wide variety of file formats compatible with the different kinds of reader devices are shown, as well as the problems derived from reader incompatibility. The more outstanding models available in the market and their services are also described. A reflection is proposed about the different usages and their effectiveness, document dissemination, and the expectations that the e-readers have created regarding future development. Nowadays these devices make the reading of electronic documents easier and more comfortable.

Design of e-books to be used in e-ink devices

Scipedia content — Mon, 08 Apr 2019 11:33:59 +0200

The multi-channel and multi-platform technologies allow the mobility of information, which has a direct impact on the evolution of the electronic book. The change is dictated by the emergence of a new generation of electronic paper devices, as well as their own models of information management. In the present paper we review the electronic book concept and present the basic characteristics of the devices that can be found on the market; then we describe the elements needed to carry out projects that produce works designed for electronic ink devices.

El libro electrónico y digital en la ecología informacional: avances y retos

Scipedia content — Mon, 08 Apr 2019 11:33:49 +0200

The problematics, context, concept and design trends of electronic books are discussed. The advantages and disadvantages of the electronic book versus the traditional one are analyzed. Finally, its impact in the ecology of book production, preservation and dissemination and in its different stakeholders is assessed, both market-oriented firms and libraries.

The polymorphic electronic book

Scipedia content — Mon, 08 Apr 2019 11:33:41 +0200

A review of the major characteristics of e-books, both as reading appliances and as content, includes a description of advantages and disadvantages, functionality, intellectual property, acceptance, market, and other considerations. The multiple different formats, devices and prices, and the absence of an important social base of users of this kind of device dedicated only to reading, make the e-book a product with a still uncertain future.

Biblioteca universitaria, crai y alfabetización informacional (María Pinto, Dora Sales y Pilar Osorio)

Scipedia content — Fri, 05 Apr 2019 16:37:29 +0200

Pinto, María; Sales, Dora; Osorio, Pilar. Biblioteca universitaria, CRAI y alfabetización informacional. Gijón: Trea, 2008. 245 p. (Biblioteca y administración cultural; 179).

Electronic resource management in libraries: what Innovative offers

Scipedia content — Fri, 05 Apr 2019 16:37:18 +0200

The management of electronic resources has become a crucial need for libraries and documentation centres. The number of e-resources that a library must manage and give access to is continually increasing. Simultaneously, new tools are needed for effective control of information about licenses, overlap between databases, contacts, and technical issues related to e-resources. The Innovative Interfaces e-resources management software, which includes a variety of integrated products that can also be deployed individually with a high level of interoperability with other companies’ products. We highlight Electronic Resources Management (ERM), the WebBridge Link Resolver, ResearchPro (a federated search engine) and the innovative Encore, which has reformulated the traditional opac approach to information access. Innovative Interfaces has also launched the CASE service, which offers coverage data about e-journals and e-resources, with additional services like marc records for e-resources to facilitate their integration in the catalogue.

El Consejo de Cooperación Bibliotecaria inicia sus actividades

Scipedia content — Fri, 05 Apr 2019 16:37:09 +0200

HA COMENZADO SU ANDADURA el Consejo de Cooperación Bibliotecaria que impulsará el desarrollo de las bibliotecas españolas de manera que se consolide el servicio público que garantiza el acceso a la información y promueve la creación de nuevo conocimiento.