Estudio de la aplicación de sistemas basados en el conocimiento a la operación de una planta de tratamiento de residuos sólidos urbanos por valorización energética

Una de las actuaciones posibles para la gestión de los residuos sólidos urbanos es la valorización energética, es decir la incineración con recuperación de energía. Sin embargo es muy importante controlar adecuadamente el proceso de incineración para evitar en lo posible la liberación de sustancias contaminantes a la atmósfera que puedan ocasionar problemas de contaminación industrial.Conseguir que tanto el proceso de incineración como el tratamiento de los gases se realice en condiciones óptimas presupone tener un buen conocimiento de las dependencias entre las variables de proceso. Se precisan métodos adecuados de medida de las variables más importantes y tratar los valores medidos con modelos adecuados para transformarlos en magnitudes de mando. Un modelo clásico para el control parece poco prometedor en este caso debido a la complejidad de los procesos, la falta de descripción cuantitativa y la necesidad de hacer los cálculos en tiempo real. Esto sólo se puede conseguir con la ayuda de las modernas técnicas de proceso de datos y métodos informáticos, tales como el empleo de técnicas de simulación, modelos matemáticos, sistemas basados en el conocimiento e interfases inteligentes. En [Ono, 1989] se describe un sistema de control basado en la lógica difusa aplicado al campo de la incineración de residuos urbanos. En el centro de investigación FZK de Karslruhe se están desarrollando aplicaciones que combinan la lógica difusa con las redes neuronales [Jaeschke, Keller, 1994] para el control de la planta piloto de incineración de residuos TAMARA. En esta tesis se plantea la aplicación de un método de adquisición de conocimiento para el control de sistemas complejos inspirado en el comportamiento humano. Cuando nos encontramos ante una situación desconocida al principio no sabemos como actuar, salvo por la extrapolación de experiencias anteriores que puedan ser útiles. Aplicando procedimientos de prueba y error, refuerzo de hipótesis, etc., vamos adquiriendo y refinando el conocimiento, y elaborando un modelo mental. Podemos diseñar un método análogo, que pueda ser implementado en un sistema informático, mediante el empleo de técnicas de Inteligencia Artificial.Así, en un proceso complejo muchas veces disponemos de un conjunto de datos del proceso que a priori no nos dan información suficientemente estructurada para que nos sea útil. Para la adquisición de conocimiento pasamos por una serie de etapas: - Hacemos una primera selección de cuales son las variables que nos interesa conocer. - Estado del sistema. En primer lugar podemos empezar por aplicar técnicas de clasificación (aprendizaje no supervisado) para agrupar los datos y obtener una representación del estado de la planta. Es posible establecer una clasificación, pero normalmente casi todos los datos están en una sola clase, que corresponde a la operación normal. Hecho esto y para refinar el conocimiento utilizamos métodos estadísticos clásicos para buscar correlaciones entre variables (análisis de componentes principales) y así poder simplificar y reducir la lista de variables. - Análisis de las señales. Para analizar y clasificar las señales (por ejemplo la temperatura del horno) es posible utilizar métodos capaces de describir mejor el comportamiento no lineal del sistema, como las redes neuronales. Otro paso más consiste en establecer relaciones causales entre las variables. Para ello nos sirven de ayuda los modelos analíticos - Como resultado final del proceso se pasa al diseño del sistema basado en el conocimiento. El objetivo principal es aplicar el método al caso concreto del control de una planta de tratamiento de residuos sólidos urbanos por valorización energética. En primer lugar, en el capítulo 2 Los residuos sólidos urbanos, se trata el problema global de la gestión de los residuos, dando una visión general de las diferentes alternativas existentes, y de la situación nacional e internacional en la actualidad. Se analiza con mayor detalle la problemática de la incineración de los residuos, poniendo especial interés en aquellas características de los residuos que tienen mayor importancia de cara al proceso de combustión.En el capítulo 3, Descripción del proceso, se hace una descripción general del proceso de incineración y de los distintos elementos de una planta incineradora: desde la recepción y almacenamiento de los residuos, pasando por los distintos tipos de hornos y las exigencias de los códigos de buena práctica de combustión, el sistema de aire de combustión y el sistema de humos. Se presentan también los distintos sistemas de depuración de los gases de combustión, y finalmente el sistema de evacuación de cenizas y escorias.El capítulo 4, La planta de tratamiento de residuos sólidos urbanos de Girona, describe los principales sistemas de la planta incineradora de Girona: la alimentación de residuos, el tipo de horno, el sistema de recuperación de energía, y el sistema de depuración de los gases de combustión Se describe también el sistema de control, la operación, los datos de funcionamiento de la planta, la instrumentación y las variables que son de interés para el control del proceso de combustión.En el capítulo 5, Técnicas utilizadas, se proporciona una visión global de los sistemas basados en el conocimiento y de los sistemas expertos. Se explican las diferentes técnicas utilizadas: redes neuronales, sistemas de clasificación, modelos cualitativos, y sistemas expertos, ilustradas con algunos ejemplos de aplicación.Con respecto a los sistemas basados en el conocimiento se analizan en primer lugar las condiciones para su aplicabilidad, y las formas de representación del conocimiento. A continuación se describen las distintas formas de razonamiento: redes neuronales, sistemas expertos y lógica difusa, y se realiza una comparación entre ellas. Se presenta una aplicación de las redes neuronales al análisis de series temporales de temperatura.Se trata también la problemática del análisis de los datos de operación mediante técnicas estadísticas y el empleo de técnicas de clasificación. Otro apartado está dedicado a los distintos tipos de modelos, incluyendo una discusión de los modelos cualitativos.Se describe el sistema de diseño asistido por ordenador para el diseño de sistemas de supervisión CASSD que se utiliza en esta tesis, y las herramientas de análisis para obtener información cualitativa del comportamiento del proceso: Abstractores y ALCMEN. Se incluye un ejemplo de aplicación de estas técnicas para hallar las relaciones entre la temperatura y las acciones del operador. Finalmente se analizan las principales características de los sistemas expertos en general, y del sistema experto CEES 2.0 que también forma parte del sistema CASSD que se ha utilizado.El capítulo 6, Resultados, muestra los resultados obtenidos mediante la aplicación de las diferentes técnicas, redes neuronales, clasificación, el desarrollo de la modelización del proceso de combustión, y la generación de reglas. Dentro del apartado de análisis de datos se emplea una red neuronal para la clasificación de una señal de temperatura. También se describe la utilización del método LINNEO+ para la clasificación de los estados de operación de la planta.En el apartado dedicado a la modelización se desarrolla un modelo de combustión que sirve de base para analizar el comportamiento del horno en régimen estacionario y dinámico. Se define un parámetro, la superficie de llama, relacionado con la extensión del fuego en la parrilla. Mediante un modelo linealizado se analiza la respuesta dinámica del proceso de incineración. Luego se pasa a la definición de relaciones cualitativas entre las variables que se utilizan en la elaboración de un modelo cualitativo. A continuación se desarrolla un nuevo modelo cualitativo, tomando como base el modelo dinámico analítico.Finalmente se aborda el desarrollo de la base de conocimiento del sistema experto, mediante la generación de reglas En el capítulo 7, Sistema de control de una planta incineradora, se analizan los objetivos de un sistema de control de una planta incineradora, su diseño e implementación. Se describen los objetivos básicos del sistema de control de la combustión, su configuración y la implementación en Matlab/Simulink utilizando las distintas herramientas que se han desarrollado en el capítulo anterior.Por último para mostrar como pueden aplicarse los distintos métodos desarrollados en esta tesis se construye un sistema experto para mantener constante la temperatura del horno actuando sobre la alimentación de residuos.Finalmente en el capítulo Conclusiones, se presentan las conclusiones y resultados de esta tesis.

Historielärares historier : Ämnesbiografi och ämnesförståelse hos gymnasielärare i historia

The overall aim of this study is to analyse history teachers’ understanding of the school subject history. The aim have also been to uncover what factors the history teachers say have affected their understanding of the school subject. Based on survey and interview methods, the question that this study deals with is: in the light of which general understanding of the school subject history, do the teachers make didactic choices on a daily basis? The first theme is biographical. The teachers’ life-history is taken into consideration and several factors in the teachers’ background and the school environment have been identified. It also seems as if the teachers’ understanding of the school subject goes from an elementary and searching approach to one that is more complex and convinced. The second theme is a more structural approach. The results shows three major orientations among the teachers’ general understanding namely, educational (bildung) orientation, critical orientation and identity orientation. Even though a main orientation can be seen among the teachers, an important result is also that the orientation is overall complex. At the most general level some patterns can be seen. First the connection between the teachers’ biography and their general understanding of the school subject. In the understanding of the school subject, it is also notable that teachers relate in different ways to history as science, history as identity and history from an ideological viewpoint. It is also possible to note some signs of change in the school subject history that follows a lager historiographical context.

Elements of a model of effective teachers

Much research in teacher education has concentrated on individual elements of effective teaching such as the best way to teach content. There has been less emphasis on understanding the complex process of effective teaching in its entirety. Teacher educators are in the business of creating effective teachers and as such need a clear, evidence based model of an effective teacher. We believe that current models of effective teachers are limited because they fail to give sufficient emphasis to many important aspects of effective teachers and fail to integrate these components into a coherent whole and so provide a language for discussion of and a conceptual framework for developing teacher education.

This paper discusses the elements needed for a model of an effective teacher. This model emphasises not only the domains of effective teaching which receive most of the attention in teacher education and evaluation, namely content knowledge, pedagogical knowledge and, more recently, pedagogical content knowledge but also takes into account the teacher's personal knowledge and knowledge of context. We suggest that it is not just this knowledge that teachers have in these domains but the way this knowledge overlaps and interacts both within the teacher and with the teacher's physical, social, intellectual and emotional environment.

An examination of the effective teacher challenges not only teacher educators to rethink the way we educate both preservice and inservice teachers; but also the way we assess, judge and reward teachers.

Generic versus subject specific pedagogy - should mathematics be in the centre?

Research into pedagogy and school change is a high priority in Australia and many other countries. This paper, which includes some preliminary findings from the Improving Middle Years Mathematics and Science: The role of subject cultures in school and teacher change (IMYMS) project, argues that, while there are key features that are common to quality learning environments across all subject areas, generic formulations of pedagogy fail to take account of the extent to which the disciplines being taught shape pedagogy or the contribution of Pedagogical Content Knowledge (PCK) to effective teaching - i.e. that there really is a need to put "mathematics in the centre ".

Cultural diversity as an educational advantage

This paper is based on a longitudinal project that looked into the management of cultural diversity in secondary schools. It discusses how Arab-Australian students and their families understand and construct their own social and educational experiences in relation to wider social discourses. The paper outlines key pedagogical initiatives and community-school partnership initiatives that have been collaboratively developed to effect positive change in the multifaceted schooling experience.

Problematising the mathematics curriculum : some examples from Australia and Japan

Problem solving is often seen as being the core of mathematics. While there are many examples of teaching for and about problem solving, there are relatively few examples of teaching mathematical content through problem solving. This paper uses data from three, apparently quite different, mathematics lessons from Australia and Japan to explore different ways in which mathematics can be taught successfully through problem solving and to analyse some of the characteristics of such lessons. It also attempts to identify some of the supports and constraints for adopting a problem solving approach to the teaching of mathematics that exist in the quite different contexts of Japan and Australia.

Exploring creative music making as a vehicle for integrated teaching and learning

The arts have evolved with each society as a means of consolidating cultural and social identity and connecting past with future generations (Russell-Bowie, 2006, p3). Situating the arts within a broader interdisciplinary curriculum, we believe, allows students to discover and explore social issues and their relevance to students' contemporary lives. We argue that creative music making through composition promotes a deeper and more personally relevant teaching and learning experience for teacher education students, particularly when situated within an interdisciplinary framework.

The challenge for us as teacher educators' is to prepare pre-service teachers for both disciplinary and interdisciplinary learning as is required by the Victorian Essential Learning Standards (VELS). At Deakin University, in the Bachelor of Teaching (Primary/Secondary) Degree, the postgraduate unit called Humanities, Societies and Environments; Language and Music Education adopts an interdisciplinary pedagogy that encourages students to learn from each other, share content knowledge and make links between and across VELS domains.

In this paper we reflect on the possibilities exploring of creative music making to enhance the teaching and learning of social education, with particular reference to issues of environmental change. Specifically, we reflect on non-music specialist students' experiences in Semester 1, 2008 using Jeannie Baker's book Window (1991) as a platform to deliberate about the impact of urbanisation on the environment. Through dramatisation and a sonic environment students were able to both further conceptualise issues of social change and their understandings of the power of integrating music across other VELS domains.

Studies on dietary fibre : analysis, epidemiological and physiological aspects

This thesis involves an investigation in three areas; first, a study of an enzymatic-gravimetric method for the analysis of dietary fibre; second, a survey of dietary fibre intake in an area of a developing country, and finally, some observations on the functional aspects of gel-forming dietary fibre in the rat. A simple and rapid enzymatic-gravimetric assay for both soluble and insoluble dietary fibre has been critically investigated. Reference samples were also analysed by a more comprehensive, enzymatic gas chromatographic method to allow testing of the relative accuracy of the enzymatic-gravimetric method. The enzymatic-gravimetric method was found to be highly reproducible but gave a slightly higher value for total dietary fibre than the more comprehensive method. This discrepancy is probably due to the presence of small quantities of resistant starch and protein residue which are recovered in the enzymatic-gravimetric method. In the enzymatic-gas chromatographic method, protein residue is not measured, and resistant starch is estimated, but not counted as dietary fibre. The enzymatic-gravimetric method was applied to the analysis of foods commonly consumed in the Padang region of West Sumatra in Indonesia, in order to estimate dietary fibre intake in the region. Daily intakes of usual foods were estimated by use of a 24-hour recall procedure aided by food photographs to assist in the estimation of portion size. Samples of approximately 60 of the most commonly consumed foods were collected and analysed for dietary fibre. These appear to be the first data which report values for dietary fibre in Indonesion foods and they represent a significant improvement upon the existing data on crude fibre content. Knowledge of the amounts of foods usually consumed and their dietary fibre content allowed an estimation of usual intakes of dietary fibre. Fibre intake was found to be lower than in the developing countries of Africa and was comparable to intakes measured in the U.K. This is the first study to show that in this part of South East Asia, a developing country area using polished rice as a staple food, dietary fibre intakes are as low as in Western countries. Low intakes of fibre are believed to be related to the prevalence of a range of diseases and, in this study, preliminary data on the rates of non-infective, chronic diseases were collected from the two main hospitals in West Sumatra. Chronic, non-infectious diseases such as inguinal hernia, appendicitis, haemorrhoids, diabetes mellitus, hypertension and malignant neoplasms of the rectum are relatively frequent in West Sumatra. While no firm conclusions can be drawn from these data, they do show the possibility of a relationship between low intakes of dietary fibre and the prevalence of these diseases, and suggest that further investigation is necessary. Some observations were made of the effect of gel-forming dietary fibre on stomach emptying and intestinal transit rate in the rat. Xanthan gum was added to iso-osmotic solutions to produce increased viscosity and phenol sulphonphthalein (phenol red) was used as a non-absorbable marker. Gavage feeding of solutions with a range of viscosities was used to study the effect of viscosity on the rate of stomach emptying and intestinal transit. Increased viscosity was observed to slow gastro-intestinal transit and this provides one mechanism by which dietary fibre of the gel-forming type ray improve glucose tolerance.

Do-it-yourself textbook review report card (Checklist)

It is argued that teachers will encounter many changes in teaching approaches and possibly in teaching materials resulting from the development and implementation of the national curriculum. With the new national curriculum, there will be new textbooks which will be 'new' as textbooks, but not necessarily new in mathematical content or instructional approaches. Two critical questions for these textbooks (or any textbooks) are: How good are these textbooks, as textbooks? How well do these textbooks fit whatever the 'new' curriculum is? Other questions to consider are: Is the content 'new' and/or substantial? Is the material 'fair' and representative? Elements of a good textbook are discussed including that it should have good design and provide good definitions, worked examples and counter-examples.

Judgement, reflexivitiy and interdisiciplinarity : reframing construction management education

A core skill of the construction management professional is decision making. Disciplinary content knowledge provides the basis for effective decision making, but is largely insufficient in contexts where projects demand a responsive and flexible approach to scenarios as they evolve and change. As Beckett and Hager suggest, ‘professional practice requires a much richer set of phenomena – a capacity to make judgements, sensitivity to intuition and an awareness of the purposes of the actions are all involved ‘(2002: 12). This paper begins by exploring judgement to develop a conceptual model for initiating and developing decision making skills for construction management professionals. The capacity to respond to change in a structured and self aware manner is examined through the concept of reflexivity, a concept borrowed from sociology. Reflexivity is an individual’s capacity to be aware, responsive and adaptability to constant changing and evolving environments. Coupled with this is the challenge for all built environment professionals in the need to integrate knowledge and processes from various specialist knowledge domains, particularly design domains. The conceptual model is then refined by synthesising concepts from interdisciplinary research.

The aim of this paper is to describe a framework to analyse and review current undergraduate and postgraduate coursework programs offerings from Deakin University in the School of Architecture and Building. Following Boud and Falchikov (2007) this framework starts with practice, that is, the actual ‘doing’ of construction management as the basis for shaping curriculum development.

Why educators should bring an end to pedagogy

As Australia is moving towards a national curriculum there are also activities to nationalise teacher education. This involves various departments of state and federal governments, third-party bodies funded by government such as the Curriculum Corporation and Teaching Australia, and non-government organisations such as the Business Council of Australia. These agencies are producing models and principles which aim on establishing standards of best practice for how they want teachers to teach. Within all of this activity the term ‘pedagogy’ is often employed to represent aspects of these best practices. Examples include ‘productive pedagogies’, ‘new pedagogies’, ‘pedagogical content knowledge’ and ‘pedagogical strategies’. However these are all means only without any end purposes which identify them as being valuable for education. In this paper I will argue that in order to have educative value teachers themselves must exercise a degree of professional autonomy to bring their own end purposes to their choice of pedagogy.

Preparing pre-service physical education teachers for uncertain future(s) : a scenario-based learning case study from Australia

Background: A key aim of a physical education teacher education (PETE) program is to promote wide and deep knowledge, enabling students to establish connections and understand contexts within and beyond education, physical education and their life worlds. Most often PETE programs equip students with content knowledge and pedagogical strategies that help them address current challenges, but less attention is directed to helping the students anticipate future challenges and engage with opportunities they may face as teachers.
Purpose: This paper presents a case study of scenario-based learning as it was implemented in a final year PETE program in an Australian university, as a means of preparing students for their future teaching careers.
Participants and setting: Twenty-five final year pre-service physical education teachers enrolled in the culminating unit of their physical education degree.
Data collection: Scenario-based learning was introduced to the students via class discussion and assigned tasks. Examples of student-written scenarios and reflection on the experience from the lecturer and student perspectives are analysed.
Findings: Although the cohort found the process of scenario-based learning daunting the post-unit questionnaires revealed that it was a valued and valuable means of exploring professional issues they will face in the future. Scenario-based learning was a powerful tool of learning as well as modelling a pedagogy students could use in the upper levels of secondary school.
Conclusion: This paper argues that scenario-based learning should be a key component of forward-looking PETE programs that encourage their graduates to solve problems about issues they may face as beginning teachers.

Leadership to improve mathematics outcomes in low SES schools and school networks

Instructional and transformational leadership is reportedly required to improve the mathematics outcomes of students in low socio-economic status school communities. This study of 43 schools in two networks of schools in rural Victoria explored leadership practices and found evidence to support both these leadership approaches along with distributed leadership practice. School leaders established network and school structures and relationships at various levels of the network and school organisation to enable and support ongoing improvement in teachers’ pedagogical content knowledge and teaching practice and to build the leadership capacity of teachers within their schools. The leaders’ knowledge of effective mathematics teaching practice enabled them to mentor teachers in their school or team and to support the practices of professional learning teams within their school.

Teaching out-of-field : factors shaping identities of secondary science and mathematics

It is widely recognised that many teachers work 'out of field', taking subjects outside their specialities. Studies undertaken by the author and by other researchers shed light on how teachers themselves experience and understand out-of-field teaching. The article discusses the issue in relation to junior secondary science and mathematics. Evidence is drawn from the 2009 Teacher Identity In and Across Subjects (TIIAS) study. The article also includes a table summarising the findings of eight major research reports relevant to this issue. The author draws a range of conclusions. Teachers' experience and understanding of out-of-field teaching is determined not only by their subject content knowledge and their pedagogical content knowledge, but also by their context and by the personal resources available to them. Rural teachers often accept the need to teach across a number of subject areas, as part of their professional identity, despite the fact that they often lack easy access to subject specialists. Teachers tend to be more positive about out-of-field teaching when they themselves have had input into which subjects they will teach, and when they have an interest in or informal knowledge of the subject area. Teachers' interest in professional development to support their out-of-field teaching is influenced by whether they see themselves as simply filling in for someone, making the most of an opportunity, or pursuing an interest. Professional learning should ideally be initiated by or negotiated with the teachers, and should be provided at the point of need. School leaderships should maximise teachers' input into subject allocation and provision of professional learning opportunities. Teacher education courses need to prepare pre-service teachers to cope with out-of-field teaching.

Teaching and learning history in primary schools : pedagogical shifts, complexities and opportunities

From 2011 the teaching and learning of History will be expanded into all primary schools (Kindergarten – Year 6) throughout Australia under a National Curriculum, including the formal preschool/kindergarten year. History as one of four core subjects will replace current studies of society and environment curriculum taught in primary schools across. The curriculum implementation process will involve a cultural and pedagogical shift as primary teachers make adjustments to the discipline of History. This article begins with an outline of the current curriculum context. An analysis of the New South Wales Human Society and Its Environment and the Australian Curriculum: History Draft Consultation documents follows. The findings indicate that the History Draft Consultation lacks clear guidance for teachers and has a number of shortcomings compared to the NSW HSIE syllabus. There are opportunities, however, for primary teachers because of the broad similarities of content knowledge in both documents and the embedded historical concepts in the NSW syllabus document.