Robust observer design by sign-stability for the monitoring of population systems

Monitoring problem in population ecology can be formalized as observer design for the population system in question: Supposing that we observe only certain species considered indicators, we want to recover or estimate the whole state process of the population system, where the state vector is usually composed from the biomasses of the single populations. In the present paper, for stably coexisting population systems, a new approach to the design of the corresponding observer system is proposed which, from the knowledge of the observed indicator(s), estimates the state process with exponential convergence. In the usual observer design, an auxiliary matrix, the so-called gain matrix must be found that guarantees the mentioned exponential convergence. The novelty is in that due to the required sign-stability (or qualitative stability) of the interaction pattern, the designed observer system (i.e. the gain matrix) is robust against quantitative changes in the inter- and intra-specific interactions. (Here the interaction pattern is described by a matrix having the signs as entries, indicating the quality of the interactions within and between the considered species.) In other words, under sign-stability conditions, in the observer design the same gain matrix can be used even if, due to environmental changes, the intensities of certain interactions suffer a quantitative change in the meanwhile. The requirement of sign-stability of the interaction pattern can be considered rather natural, since in a stably coexisting population system, it means for example that a predator–prey relation does not change into a prey–predator interaction, and interactions neither appear nor disappear within the system. Our approach to robust observer design is illustrated on model population systems, such as trophic chains of type resource-producer-primary consumer-secondary consumer and Lotka–Volterra system with vertical structure. For the latter system a Lyapunov function is also constructed that guarantees the global asymptotic stability of the positive equilibrium of the considered model.     

Islamic glasses from Al-Andalus. Characterisation of materials from a Murcian workshop (12th century AD, Spain)

Rescue archaeological excavations at an urban glass workshop of the 12th century AD in the city of Murcia (Spain) have provided one of the few evidences of glass production in the ancient Islamic territory of Al-Andalus. This paper reports the results derived from a chemical–physical characterisation study carried out on a representative sample set of glass fragments and industrial debris from that workshop. The main objectives of the research were to contribute to the knowledge of the type of glasses produced and provide some insights into the technology developed to obtain different colours in glasses. The resulting data indicated that both high-magnesia plant ash (HMG) soda-lime-silicate and soda-lime lead-silicate glasses were produced. They also indicated a deep knowledge of glass colouring techniques, which suggests that a careful control over the glass melting processes was achieved. Among others, the occurrence of bulk-coloured silver yellow and copper ruby red transparent glasses prove the skills reached by Murcian glassmakers. These results shed new light on the Islamic glass technology of a geographical area in which, up to now, little compositional and technological data from glass workshops were available.     

Antecedents of Incidental News Exposure: The Role of Media Preference,Use and Trust

ABSTRACT

The online environment has radically changed the way in which users consume, discover and manipulate news. The growing relevance of social media platforms and digital intermediaries for news sharing and consumption increase the likelihood of citizens to be exposed to online news even when they are not seeking it. This digital transformation fundamentally challenges the way online news use and exposure have been conceptualized and measured, affecting also to citizens’ knowledge about public affairs and politics. This article examines the factors that predict the probability to be an “incidentally exposed news user” online. Specifically, based on a representative US sample from the Pew Research Centre, this study analyses the role of media preference, use and trust. Findings indicate that beyond users’ demographics and loyalty, readers’ news preferences, uses and trust, specially of social media platforms, affect their probability to be incidentally exposed to news online. These results have important empirical and theoretical implications for understanding the connection between readers’ news consumption patterns and online exposure, intentional or incidental.     

Fruitful student interactions and perceived learning improvement in DSLab: A dynamic assessment tool for distributed programming

This work presents an automated assessment tool for online distributed programming, called DSLab. It is a web-based environment that provides a transparent deployment and execution of assignments in remote computers, a transparent initialization and the possibility to add new logs by the students. DSLab has been evaluated in a real distributed learning environment by analysing students' own perceptions on their learning improvement and exploring whether students' interactions with the tool yielded a fruitful learning experience. Current research provides no evidence that the effects of such a tool have been investigated in the field of online distributed programming. Two types of analysis were performed: a quantitative analysis of data coming from students answering a questionnaire and an analysis of the log files of students' interactions with the tool. Our results showed that students perceived substantial learning improvement from the use of the automated assessment tool. Moreover, students produced fruitful interaction with the tool as soon as they achieved high familiarization and constant activity with it, which ultimately helped them improve their academic performance. Finally, the limitations of the current study and directions for future research are presented.     

Multimedia integration for language e-learning： Content, context and the e-dossier

In the education world, it is widely accepted that language learning is one of the pioneering disciplines in the application and use of the information and communication technologies, initially preceded by the widespread use of audiovisual resources which, finally integrated in the digital space, bring about the use of multimedia. Additionally, language learning has greatly contributed to standardizing lesson plans. They set the basis for learning design, one of the last advances in the pedagogical organization of education through the use of computers in learning managing systems. Most recently, language learning has also played an innovative role in the implementation of portfolios to education. These three perspectives address different issues for e-learning： the access to content through technology; the design of the learning initially with the help of tutors and then applying institutional frameworks for their own personal learning processes; and the edition of the resulting e-learning experience as evidence with the e-dossier, a part of the e-portfolio. Currently, the web is evolving towards its original function as the read/write web where the user, apart from accessing information, can create their own information and communicate more interactively, using technology-enhanced learning environments to integrate text and multimedia for real audiences both in the classroom and outside. Thus, taking language learning guided by the Common European Framework of Reference for Languages, the authors present here a complete e-learning system which integrates textual as well as multimedia facilities to acquire learning content, edit learning design and report learning experiences.     

Scale of spectators’ motivations at soccer events

There are motivation sports events attending measuring tools, although so far these instruments have only been able to provide a limited explanation for attendance, which means that more sophisticated, useful scales are required. The aim of this research is to provide more efficient tool to measure the motivations of soccer events attendance. With this aim, a 14-item scale has been developed to measure the motivations that have been identified in a comprehensive review of specialized marketing literature. This scale, was used during a soccer event, showed a good global adjustment, internal consistency and validity, and found the following four dimensions explained 67% of variance in attendance: excitement, aesthetics, escape and connections to the team and its environment.     

Governance Dynamics and the Application of the Multilevel Governance Approach in Vocational Education and Training (VET) in the European Neighbourhood Countries: the case of the ENPI South region

This article analyses moves towards good multilevel governance approaches in Vocational Education and Training (VET) as an effective way to improve VET policy making in transition and developing countries, focusing on the Southern Neighbourhood of the EU (ENPI South). The centralised approaches in public administration and to VET governance still prevail in this region. The new modes of governance applied by the EU in the policy area of education and training are based on the Open Method of Coordination (OMC). They are a source of inspiration to improve VET governance, taking into account the complexity of VET policies and systems. According to current European and international experiences, the most effective, relevant and attractive VET models and systems are demand‐driven. They rely on the effective and accountable participation of both state (national/local public actors) and non‐state VET stakeholders (e.g. employers, sectoral actors, unions) in decision‐making and policy implementation processes. This could also pave the way towards self‐governed and performance‐based VET provider institutions which would give quicker responses to rapidly changing labour market skills, competences and qualification needs. Thus, this means putting in practice more and better inclusion and effective cooperation and coordination of regional and local voices of VET actors and developing stronger social partnerships to engage employers, unions and civil society in shaping and investing in skills development. Furthermore, the role of methodological tools for VET governance is not only to provide an analytical ground to capture data and structure further policy advice. These tools can also be used as ice‐breakers to improve collaboration, inclusiveness, multi‐participation and trust‐building among policy makers as they work together on very sensitive issues such as reviewing country VET governance models, modes and institutional arrangements, and/or planning policy thinking and/or learning for implementing coordination mechanisms for VET policy making. The European Training Foundation (ETF) has implemented a methodology to map, analyse and self‐assess good multilevel governance in VET, inspired by how EU governance soft tools in education and training are being used. This methodology has been applied to the Governance for Employability in the Mediterranean (GEMM) project in the ENPI South region, which is a regional project implemented by the ETF and financed by the European Commission's Directorate General for Neighbourhood and Enlargements Negotiations (NEAR).