Un experimento de enseñanza sobre el límite de una función. Factores determinantes en una trayectoria de aprendizaje

El objetivo del estudio fue identificar características de la construcción del significado de límite de una función en estudiantes de bachillerato (16-17 años). Se diseñó un experimento de enseñanza utilizando una descomposición genética (APOE) del concepto de límite de una función integrando recursos informáticos. Se usó el constructo “Reflexión sobre la Relación Actividad-Efecto” (Simon, Tzur, Heinz y Kinzel, 2004) como una particularización de la abstracción reflexiva para identificar factores que configuran la Trayectoria de Aprendizaje. Los resultados indican que la trayectoria está determinada por la coordinación de las aproximaciones en el dominio y en el rango en diferentes tipos de funciones.

Teachers’ beliefs about diversity: an analysis from a personal and professional perspective

The purpose of this study was to examine the beliefs that teachers have about diversity and their level of sensitivity towards some topics related to it. Moreover, beliefs were compared according to teachers’ personal and professional views and teaching experience. The Personal and Professional Beliefs about Diversity Scales (Pohan and Aguilar, 1999) were administered to a sample of 233 teachers. Results showed highly positive beliefs towards diversity in all its dimensions (cultural, linguistic and social diversity, ability, gender, sexual orientation and religion), especially regarding its personal implications compared to the professional ones. Likewise, it was observed a significant relationship between years of teaching experience and professional beliefs about diversity, so teachers with no school experience showed a higher tolerance than those with teaching experience, mainly in aspects related to cultural, linguistic and social differences, ability and gender. The implications that these results have for educational practice and the need for the development of multicultural education courses that favour an effective teaching are discussed.

Projeto Europeu INTACT: a educação em ciências torna-se móvel

A par de outras cinco instituições de ensino superior europeias, o Instituto Politécnico de Bragança integra o projeto INTACT (Interactive Teaching Across Culture and Technology) em que está em foco o planeamento, a criação e a implementação de uma plataforma com recursos educativos adaptáveis a diferentes níveis de ensino com o pressuposto de o processo de ensino/aprendizagem ser bilingue e colaborativo (http://www.intact-comenius.eu). A entrevista desta edição foi feita à coordenadora do projeto, Professora Christine Bescherer da Universidade de Educação de Ludwigsburgo na Alemanha e ela explica o fundamental do projeto.

The European Union’s Response to Piracy: Are the Lessons Learned in the Horn of Africa a Model for the Gulf of Guinea? EU Diplomacy Paper/2015

The European Union (EU) is seen as the leading actor in successfully fighting piracy around the Horn of Africa. As a global trade power with strong economic interests, the EU is also challenged by similar maritime security threats in the Gulf of Guinea. To date, there has been no comprehensive analysis to assess the potential transfer of successful EU instruments from the Horn of Africa to the piracy situation in West African waters. This paper examines to what extent the EU can draw on its experience made in the Horn of Africa to deter piracy in West African waters. Based on qualitative research interviews, lessons learned from East Africa are identified and subsequently applied to the situation in the Gulf of Guinea. The results show that the EU is only partially drawing on its experience made in the Horn of Africa. One the one hand, it is rather reluctant to use crisis management instruments such as naval operations. On the other hand, the EU is drawing on its successful leadership in international political and military cooperation from around the Horn of Africa in order to make more effective use of available resources in the Gulf of Guinea.

Getting the most from a site visit : a guide to assist schools visiting a Leadership and Learning Site for Reading Best Practices /

Includes a list of the Reading Best Practice Sites in Illinois and a list of the possible teaching strategies that are appropriate with each of the fourteen Best Practices.

A funny thing happened on the way to the forum: Electronic discussion and foreign language learning

Amongst the opportunities for cross-cultural contact created by the burgeoning use of the Internet are those provided by electronic discussion lists. This study looks at what happens when language students venture out of the classroom (virtual or otherwise) to participate in on-line discussion groups with native speakers. Responses to messages and commentary by moderators and other participants on the (in) appropriateness of contributions allow us to determine what constitutes successful participation and to make suggestions regarding effective teaching strategies for this medium. A case study examines the threads started by four anglophone students of French when they post messages to a forum on the Web site of the French newspaper Le Monde. Investigation of these examples points to the ways in which electronic discussion inflects and is inflected by cultural and generic expectations. We suggest that successful participation on Internet fora depends on awareness of such cultural and generic mores and an ability to work within and/or with them. Teachers therefore need to find ways in which students can be sensitized to such issues so that their participation in such electronic discussion is no longer seen as linguistic training, but as engagement with a cultural practice.

The judicious utilization of new technologies through authentic learning in higher education: A case study

Though technology holds significant promise for enhanced teaching and learning it is unlikely to meet this promise without a principled approach to course design. There is burgeoning discourse about the use of technological tools and models in higher education, but much of the discussion is fixed upon distance learning or technology based courses. This paper will develop and propose a balanced model for effective teaching and learning for “on campus” higher education, with particular emphasis on the opportunities for revitalisation available through the judicious utilisation of new technologies. It will explore the opportunities available for the creation of more authentic learning environments through the principled design. Finally it will demonstrate with a case study how these have come together enabling the creation of an effective and authentic learning environment for one pre-service teacher education course at the University of Queensland.

Filtering duplicate items over distributed data streams

In recent years many real time applications need to handle data streams. We consider the distributed environments in which remote data sources keep on collecting data from real world or from other data sources, and continuously push the data to a central stream processor. In these kinds of environments, significant communication is induced by the transmitting of rapid, high-volume and time-varying data streams. At the same time, the computing overhead at the central processor is also incurred. In this paper, we develop a novel filter approach, called DTFilter approach, for evaluating the windowed distinct queries in such a distributed system. DTFilter approach is based on the searching algorithm using a data structure of two height-balanced trees, and it avoids transmitting duplicate items in data streams, thus lots of network resources are saved. In addition, theoretical analysis of the time spent in performing the search, and of the amount of memory needed is provided. Extensive experiments also show that DTFilter approach owns high performance.

O PERFIL PROFISSIONAL DO SUPERVISOR DE ENSINO

Numa perspectiva sociológica, este trabalho tem o objetivo de identificar o perfil profissional do supervisor de ensino que atua na Secretaria de Estado da Educação de São Paulo, verificando se sua atuação está voltada ao pedagógico ou ao administrativo e qual o compromisso político e as concepções educacionais destes profissionais. Apoiando-se em Tragtenberg, Silva Jr e Huert, entre outros autores que abordam, especificamente, a supervisão de ensino, procurou-se fazer uma analise histórica da legislação, de planilhas e dos dados que foram colhidos através de depoimentos e entrevistas com supervisores de ensino efetivos de três Diretorias de Ensino da Grande São Paulo. O resultado da pesquisa aponta para a predominância de um perfil burocrático e de fiscalização na ação do supervisor de ensino, bem como de executor das políticas públicas e não partícipe da sua elaboração. O supervisor de ensino é um representante de um poder político que favorece uma determinada ordem, mesmo que exista uma tentativa de superação de uma representatividade unilateral dentro da supervisão de ensino.(AU)

Mathematical modelling and optimal multivariable control of chemical processes

This work reports the developnent of a mathenatical model and distributed, multi variable computer-control for a pilot plant double-effect climbing-film evaporator. A distributed-parameter model of the plant has been developed and the time-domain model transformed into the Laplace domain. The model has been further transformed into an integral domain conforming to an algebraic ring of polynomials, to eliminate the transcendental terms which arise in the Laplace domain due to the distributed nature of the plant model. This has made possible the application of linear control theories to a set of linear-partial differential equations. The models obtained have well tracked the experimental results of the plant. A distributed-computer network has been interfaced with the plant to implement digital controllers in a hierarchical structure. A modern rnultivariable Wiener-Hopf controller has been applled to the plant model. The application has revealed a limitation condition that the plant matrix should be positive-definite along the infinite frequency axis. A new multi variable control theory has emerged fram this study, which avoids the above limitation. The controller has the structure of the modern Wiener-Hopf controller, but with a unique feature enabling a designer to specify the closed-loop poles in advance and to shape the sensitivity matrix as required. In this way, the method treats directly the interaction problems found in the chemical processes with good tracking and regulation performances. Though the ability of the analytical design methods to determine once and for all whether a given set of specifications can be met is one of its chief advantages over the conventional trial-and-error design procedures. However, one disadvantage that offsets to some degree the enormous advantages is the relatively complicated algebra that must be employed in working out all but the simplest problem. Mathematical algorithms and computer software have been developed to treat some of the mathematical operations defined over the integral domain, such as matrix fraction description, spectral factorization, the Bezout identity, and the general manipulation of polynomial matrices. Hence, the design problems of Wiener-Hopf type of controllers and other similar algebraic design methods can be easily solved.

Packet switching in wide area broadband private networks

B-ISDN is a universal network which supports diverse mixes of service, applications and traffic. ATM has been accepted world-wide as the transport technique for future use in B-ISDN. ATM, being a simple packet oriented transfer technique, provides a flexible means for supporting a continuum of transport rates and is efficient due to possible statistical sharing of network resources by multiple users. In order to fully exploit the potential statistical gain, while at the same time provide diverse service and traffic mixes, an efficient traffic control must be designed. Traffic controls which include congestion and flow control are a fundamental necessity to the success and viability of future B-ISDN. Congestion and flow control is difficult in the broadband environment due to the high speed link, the wide area distance, diverse service requirements and diverse traffic characteristics. Most congestion and flow control approaches in conventional packet switched networks are reactive in nature and are not applicable in the B-ISDN environment. In this research, traffic control procedures mainly based on preventive measures for a private ATM-based network are proposed and their performance evaluated. The various traffic controls include CAC, traffic flow enforcement, priority control and an explicit feedback mechanism. These functions operate at call level and cell level. They are carried out distributively by the end terminals, the network access points and the internal elements of the network. During the connection set-up phase, the CAC decides the acceptance or denial of a connection request and allocates bandwidth to the new connection according to three schemes; peak bit rate, statistical rate and average bit rate. The statistical multiplexing rate is based on a `bufferless fluid flow model' which is simple and robust. The allocation of an average bit rate to data traffic at the expense of delay obviously improves the network bandwidth utilisation.

Raising the bar for systematic conservation planning

Mathematical methods in systematic conservation planning (SCP) represent a significant step toward cost-effective, transparent allocation of resources for biodiversity conservation. However, research demonstrates important consequences of uncertainties in SCP. Current research often relies on simplified case studies with unknown forms and amounts of uncertainty and low statistical power for generalizing results. Consequently, conservation managers have little evidence for the true performance of conservation planning methods in their own complex, uncertain applications. SCP needs to build evidence for predictive models of error and robustness to multiple, simultaneous uncertainties across a wide range of problems of known complexity. Only then can we determine true performance rather than how a method appears to perform on data with unknown uncertainty.

Minority enterprise in the clothing industry: an analysis of Asian jeans manufacturers in Birmingham

This thesis discusses and assesses the resources available to Asian entrepreneurs in the West Midlands' clothing industry and how they are used by these small businessmen in order to address opportunities in the market economy within the constraints imposed. The fashion industry is volatile and is dependent upon flexible firms which can respond quickly to shortrun production schedules. Small firms are best able to respond to this market environment. Production of jeans presents an interesting departure from the mainstream fashion industry. It is traditionally gared towards longrun production schedules where multinational enterprises have artificially diversified the market, promoting the 'right' brand name and have established control of the upper end of the market, whilst imports from Newly Developing Countries have catered for cheap copies at the lower end of the market. In recent years, a fashion element to jeans has emerged, thus opening a market gap for U.K. manufacturers to respond in the same way as for other fashion articles. A large immigrant population, previously serving the now declining factories and foundries of the West Midlands but, through redundancy, no longer a part of this employment sector, has ~5ponded to economic constraints and market opportunities by drawing on ethnic network resources for competitive access to labour, finance and contacts, to attack the emergent market gap. Two models of these Asian entrepreneurs are developed. One being somecne who has professionally and actively tackled the market gap and become established. These entrepreneurs are usually educated and have personal experience in business and were amongst the first to perceive opportunities to enter the industry, actively utilising their ethnicity as a resource upon which to draw for favorable access to cheap, flexible labour and capital. The second model is composed of later entrants to jeans manufacturing. They have less formal education and experience and have been pushed into self-employment by constraints of unemployment. Their ethnicity is passively used as a resource. They are more likely confined to the marginal activity of 'cut make and trim' and have little opportunity to increase profit margins, become estalished or expand.

Ensuring efficiency and robustness in MANET

This paper introduces a joint load balancing and hotspot mitigation protocol for mobile ad-hoc network (MANET) termed by us as 'load_energy balance + hotspot mitigation protocol (LEB+HM)'. We argue that although ad-hoc wireless networks have limited network resources - bandwidth and power, prone to frequent link/node failures and have high security risk; existing ad hoc routing protocols do not put emphasis on maintaining robust link/node, efficient use of network resources and on maintaining the security of the network. Typical route selection metrics used by existing ad hoc routing protocols are shortest hop, shortest delay, and loop avoidance. These routing philosophy have the tendency to cause traffic concentration on certain regions or nodes, leading to heavy contention, congestion and resource exhaustion which in turn may result in increased end-to-end delay, packet loss and faster battery power depletion, degrading the overall performance of the network. Also in most existing on-demand ad hoc routing protocols intermediate nodes are allowed to send route reply RREP to source in response to a route request RREQ. In such situation a malicious node can send a false optimal route to the source so that data packets sent will be directed to or through it, and tamper with them as wish. It is therefore desirable to adopt routing schemes which can dynamically disperse traffic load, able to detect and remove any possible bottlenecks and provide some form of security to the network. In this paper we propose a combine adaptive load_energy balancing and hotspot mitigation scheme that aims at evenly distributing network traffic load and energy, mitigate against any possible occurrence of hotspot and provide some form of security to the network. This combine approach is expected to yield high reliability, availability and robustness, that best suits any dynamic and scalable ad hoc network environment. Dynamic source routing (DSR) was use as our underlying protocol for the implementation of our algorithm. Simulation comparison of our protocol to that of original DSR shows that our protocol has reduced node/link failure, even distribution of battery energy, and better network service efficiency.

Enabling transparent technologies for the development of highly granular flexible optical cross-connects

Flexible optical networking is identified today as the solution that offers smooth system upgradability towards Tb/s capacities and optimized use of network resources. However, in order to fully exploit the potentials of flexible spectrum allocation and networking, the development of a flexible switching node is required capable to adaptively add, drop and switch tributaries with variable bandwidth characteristics from/to ultra-high capacity wavelength channels at the lowest switching granularity. This paper presents the main concept and technology solutions envisioned by the EU funded project FOX-C, which targets the design, development and evaluation of the first functional system prototype of flexible add-drop and switching cross-connects. The key developments enable ultra-fine switching granularity at the optical subcarrier level, providing end-to-end routing of any tributary channel with flexible bandwidth down to 10Gb/s (or even lower) carried over wavelength superchannels, each with an aggregated capacity beyond 1Tb/s. © 2014 IEEE.