Measurements, Models, Systems and Design

531 s.

Strategic Research Agenda for organic food and farming

The TP Organics Strategic Research Agenda (SRA) was finalised in December 2009. The purpose of the Strategic Research Agenda (SRA) is to enable research, development and knowledge transfer that will deliver relevant outcomes – results that will contribute to the improvement of the organic sector and other low external input systems. The document has been developed through a dynamic consultative process that ran from 2008 to 2009. It involved a wide range of stakeholders who enthusiastically joined the effort to define organic research priorities. From December 2008 to February; the expert groups elaborated the first draft. The consultative process involved the active participation of many different countries. Consultation involved researchers, advisors, members of inspection/certification bodies, as well as different users/beneficiaries of the research such as farmers, processors, market actors and members of civil society organisations throughout Europe and further afield in order to gather the research needs of the whole organic sector

2015 Annual Research Symposium Abstract Book

2015 annual volume of abstracts for science research projects conducted by students at Trinity Colleg

Economic considerations for adaptability in buildings

The existing buildings in the UK are not designed to be functionally adaptive to fit a spectrum of purposes. Alternatively, scrapping these buildings and building anew does not appear to be an economically viable and environmentally sustainable solution either. Proactive solutions to respond to future potential changes of use are rare in previous and current building designs, which ultimately make these buildings functionally redundant. At present, curiosity about adaptable buildings is spreading among owners, developers and policy makers; however, no detailed investigation has been undertaken to identify the economic costs and benefits of adaptability in new buildings. Thus, the present endeavour was designed to bridge this gap. The research exploited both case studies and survey designs to explore the answers to the above problem. Two case studies were undertaken to establish that building changes occur over time, as well as to assess their economic implications in the current built environment at both macro and micro levels. Three web-based surveys (WBS) were designed and circulated among quantity surveyors and architects of the 100 leading consultancy practices in the UK to identify both the design and economic aspects of adaptability in buildings. The total numbers of respondents to WBS1, WBS2 and WBS3 were 13, 32 and 42, respectively. In addition, data was collected from semi-structured interviews with two policy makers, two structural engineers, a quantity surveyor and a facilities manager. Unstructured interviews with a senior planner, a project manager, two architects and a services engineer were used to clarify the issues of design and planning for adaptability in buildings. The findings were interwoven to develop a conceptual framework to identify the economic considerations for adaptability in new buildings. Two workshops were undertaken with the industry partners for the Adaptable Futures research project to verify the results obtained from the case studies and to test the usability of the developed conceptual framework. The group members had multi-disciplinary backgrounds of architecture, quantity surveying and structural engineering, allowing a robust grounding for verification. The results contribute to the body of knowledge in two ways. Firstly, the developed conceptual framework identifies the economic considerations (costs and benefits) for change of use in buildings within the wider context of adaptability over the lifecycle aspects. This will assist owners/clients and developers in their economic decisions for designing new buildings for potential adaptations. Secondly, the research findings strengthen the reliability of the existing body of knowledge whilst confirming the urgent need for designing new buildings towards potential adaptations. In addition, the findings strongly emphasise plan depth and floor to ceiling height as the most influential design parameters for building change of use, the details of which are not highlighted in the previous literature

Intelligent design of manufacturing systems.

The design of a manufacturing system is normally performed in two distinct stages, i.e. steady state design and dynamic state design. Within each system design stage a variety of decisions need to be made of which essential ones are the determination of the product range to be manufactured, the layout of equipment on the shopfloor, allocation of work tasks to workstations, planning of aggregate capacity requirements and determining the lot sizes to be processed. This research work has examined the individual problem areas listed above in order to identify the efficiency of current solution techniques and to determine the problems experienced with their use. It has been identified that for each design problem. although there are an assortment of solution techniques available, the majority of these techniques are unable to generate optimal or near optimal solutions to problems of a practical size. In addition, a variety of limitations have been identified that restrict the use of existing techniques. For example, existing methods are limited with respect to the external conditions over which they are applicable and/or cannot enable qualitative or subjective judgements of experienced personnel to influence solution outcomes. An investigation of optimization techniques has been carried out which indicated that genetic algorithms offer great potential in solving the variety of problem areas involved in manufacturing systems design. This research has, therefore, concentrated on testing the use of genetic algorithms to make individual manufacturing design decisions. In particular, the ability of genetic algorithms to generate better solutions than existing techniques has been examined and their ability to overcome the range of limitations that exist with current solution techniques. IIFor each problem area, a typical solution has been coded in terms of a genetic algorithm structure, a suitable objective function constructed and experiments performed to identify the most suitable operators and operator parameter values to use. The best solution generated using these parameters has then been compared with the solution derived using a traditional solution technique. In addition, from the range of experiments undertaken the underlying relationships have been identified between problem characteristics and optimality of operator types and parameter values. The results of the research have identified that genetic algorithms could provide an improved solution technique for all manufacturing design decision areas investigated. In most areas genetic algorithms identified lower cost solutions and overcame many of the limitations of existing techniques

2015 Summer Research Symposium Abstract Book

2015 Summer volume of abstracts for science research projects conducted by students at Trinity College

Contributions to cascade linear control strategies applied to grid-connected Voltage-Source Converters

El trabajo desarrollado en esta Tesis se centra en optimizar el comportamiento de Voltage-Source Converters (VSCs) cuando son utilizados como interfaz con la red eléctrica, tanto para absorber como para entregar energía de la red con la mejor calidad posible y cumpliendo con los estándares. Para tal fin, esta Tesis se centra en el control de sistemas lineales conectados en cascada aplicados al control de VSCs conectados en paralelo con la red eléctrica a través de un filtro L, especialmente en conexiones con redes débiles y en dos líneas de trabajo: (i) seguimiento de armónicos de las corrientes de red y rechazo de armónicos de las tensiones de red, y (ii) control de la tensión del PCC en caso de desequilibrio. Para ello, esta Tesis realiza contribuciones en el área del control de corriente y control de la tensión del PCC. De entre las técnicas existentes para implementar el control de corriente para compensación armónica, dos de las más utilizadas son el control resonante y el control repetitivo, tanto en ejes de referencia estacionarios como síncronos. Se ha realizado un exhaustivo estudio de diferentes estructuras para implementar tales controles, mostrando su algoritmo adaptativo en frecuencia para cada una de ellas y analizando su carga computacional. Además, se han facilitado directrices básicas para su programación en un DSP. Se ha analizado también el esquema de control de corriente para establecer una comparación entre las diferentes estructuras. Después de estudiar en profundidad el control de corriente de un VSC conectado a la red eléctrica, el segundo control a analizar es el control de tensión del PCC. La presencia de una tensión desequilibrada en el PCC da lugar a la aparición de una componente de corriente de secuencia negativa, que deteriora el comportamiento del sistema de control cuando se emplean las técnicas de control convencionales. Los STATCOMs son bien conocidos por ser una aplicación de potencia capaz de llevar a cabo la regulación de la tensión en el PCC en líneas de distribución que pueden ser susceptibles de sufrir perturbaciones. Esta Tesis propone el uso de un controlador de tensión en ejes de referencia síncronos para compensar una tensión desequilibrada a través de un STATCOM, permitiendo controlar independientemente tanto la secuencia positiva como la secuencia negativa. Además, este controlador incluye aspectos como un mecanismo de antiwindup y droop control para mejorar su comportamiento. Se han realizado varias pruebas experimentales para analizar las características de los controladores de corriente abordados en esta Tesis. Todas ellas han sido realizadas bajo las mismas condiciones de potencia, tensión y corriente, de modo que se pueden extraer resultados comparativos. Estas pruebas pretenden caracterizar la respuesta transitoria, la respuesta en régimen permanente, el comportamiento frente a saltos de frecuencia y la carga computacional de los controladores de corriente estudiados