Hierarchical fuzzy logic based approach for object tracking

In this paper a novel tracking approach based on fuzzy concepts is introduced. A methodology for both single and multiple object tracking is presented. The aim of this methodology is to use these concepts as a tool to, while maintaining the needed accuracy, reduce the complexity usually involved in object tracking problems. Several dynamic fuzzy sets are constructed according to both kinematic and non-kinematic properties that distinguish the object to be tracked. Meanwhile kinematic related fuzzy sets model the object's motion pattern, the non-kinematic fuzzy sets model the object's appearance. The tracking task is performed through the fusion of these fuzzy models by means of an inference engine. This way, object detection and matching steps are performed exclusively using inference rules on fuzzy sets. In the multiple object methodology, each object is associated with a confidence degree and a hierarchical implementation is performed based on that confidence degree.info:eu-repo/semantics/publishedVersio

Automatic histogram threshold using fuzzy measures

In this paper, an automatic histogram threshold approach based on a fuzziness measure is presented. This work is an improvement of an existing method. Using fuzzy logic concepts, the problems involved in finding the minimum of a criterion function are avoided. Similarity between gray levels is the key to find an optimal threshold. Two initial regions of gray levels, located at the boundaries of the histogram, are defined. Then, using an index of fuzziness, a similarity process is started to find the threshold point. A significant contrast between objects and background is assumed. Previous histogram equalization is used in small contrast images. No prior knowledge of the image is required.info:eu-repo/semantics/publishedVersio

Benchmarking some Portuguese S&T system research units: 2nd Edition

The increasing use of productivity and impact metrics for evaluation and comparison, not only of individual researchers but also of institutions, universities and even countries, has prompted the development of bibliometrics. Currently, metrics are becoming widely accepted as an easy and balanced way to assist the peer review and evaluation of scientists and/or research units, provided they have adequate precision and recall. This paper presents a benchmarking study of a selected list of representative Portuguese research units, based on a fairly complete set of parameters: bibliometric parameters, number of competitive projects and number of PhDs produced. The study aimed at collecting productivity and impact data from the selected research units in comparable conditions i.e., using objective metrics based on public information, retrievable on-line and/or from official sources and thus verifiable and repeatable. The study has thus focused on the activity of the 2003-06 period, where such data was available from the latest official evaluation. The main advantage of our study was the application of automatic tools, achieving relevant results at a reduced cost. Moreover, the results over the selected units suggest that this kind of analyses will be very useful to benchmark scientific productivity and impact, and assist peer review.Comment: 26 pages, 20 figures F. Couto, D. Faria, B. Tavares, P. Gon\c{c}alves, and P. Verissimo, Benchmarking some portuguese S\&T system research units: 2nd edition, DI/FCUL TR 13-03, Department of Informatics, University of Lisbon, February 201

Impacto visual dos estaleiros de construção nos centros urbanos

Este artigo pretende abordar os diversos impactos que os estaleiros de construção provocam na sua área de implantação e imediações. Analise-se de forma mais pormenorizada o impacto visual que estes têm nos meios urbanos e em particular nos centros históricos, apresentando alguns casos com impacto marcadamente negativo e outros onde a solução pretende e consegue enquadrar de forma harmoniosa o estaleiro com a envolvente. São enumeradas e sugeridas formas de minimizar este impacto

Estándares territoriales de innovación : análisis de las regiones de Portugal

Competitiveness among regions and innovation dynamics are intimately related and depend on a solid and effective innovation system. This study aims to measure innovativeness in different Portuguese regions and to evaluate the nature of the innovation process and the relationship between innovativeness and its region of origin. To characterize the territorial innovation processes and to identify innovation patterns by regions, it analyzes their main distinctive factors, based on the Community Innovation Survey results for each region. Thus, it compares the Portuguese regions by verifying the existence of subjacent clusters and finding out the characteristics that distinguish the different groups of regions. The results point to the existence of four groups of regions, and the factors identified are related to the innovation process, namely objectives of innovation, sources of innovation, collaborative networks, triple helix performance, and obstacles to innovation.RESUMEN: La competitividad entre las regiones y la dinámica de la innovación están íntimamente relacionadas y dependen de un sistema de innovación sólida y eficaz. Este estudio tiene como objetivo medir la capacidad de innovación en diferentes regiones portuguesas y evaluar la naturaleza del proceso de innovación y la relación entre la capacidad de innovación y su región de origen. Para la caracterización de los procesos de innovación territoriales y identificar estándares de innovación en las regiones, este artículo analiza sus factores distintivos principales, con base en los resultados de las encuestas comunitarias sobre innovación para cada región. Por lo tanto, se comparan las regiones portuguesas mediante la verificación de la existencia de agrupaciones subyacentes y descubrir las características que distinguen a los diferentes grupos de regiones. Los resultados apuntan a la existencia de cuatro grupos de regiones, y los factores identificados están relacionados con el proceso de innovación, es decir, los objetivos de la innovación, las fuentes de innovación, redes de colaboración, el funcionamiento de la triple hélice, y los obstáculos a la innovación.info:eu-repo/semantics/publishedVersio

As consequências do incumprimento dos prazos para a competitividade da indústria de construção : razões para os atrasos

Este artigo pretende divulgar o estudo que tem decorrido na Universidade do Minho sobre a problemática dos incumprimentos dos prazos de construção. Numa primeira fase centrou-se na identificação das causas dos atrasos dos projectos de construção, nos métodos da sua resolução e aspectos afins, numa segunda fase procedeu-se à elaboração e implementação de um inquérito às partes envolvidas nas actividades de construção

Using linear model for learning curve effect on highrise floor construction

The evolution of repetitive scheduling methods led to the introduction of the learning concept in construction planning. It is common knowledge that performing the same activity repeatedly, and in the same conditions, takes less and less time as the activity is repeated (Gates and Scarpa, 1972). This phenomenon is clear in many construction activities and is known as learning experience or learning effect. The increase in productivity is mainly due to the increasing knowledge acquired by work repetition. Graphic representation is through a learning curve that admits duration decreases as the activity is repeated, according to a predictable and constant learning rate. The Linear Model of logarithmic coordinates (log10Y 5 log10A – nlog10X) was applied to two repetitive construction processes, frequently used in Portuguese construction. The intent was to examine its applicability and efficiency in predicting future performances, and the interest in incorporating the model in new planning methodologies for repetitive construction. In both cases, learning processes were created

Método das curvas de equilíbrio no planeamento da construção repetitiva em altura

A abordagem do planeamento da construção repetitiva iniciou-se com os métodos tradicionais de programação. Porém, dadas as suas limitações no tratamento do problema desenvolveram-se métodos específicos para este tipo de construção, e mais recentemente introduziu-se o conceito de aprendizagem. Neste trabalho apresenta-se um novo método de programação dos trabalhos repetitivos, dotado dos atributos das metodologias tradicionais e das vantagens que resultam da utilização de métodos específicos na programação daquele tipo de trabalhos e que inclui a consideração do efeito da aprendizagem

Reasons for the lack of competitiveness of the portuguese construction industry

The last few years have confirmed what was mostly feared: Portuguese construction industry suffers from a chronic disease - the lack of competitiveness. Symptoms have long been recognised in several construction projects: frequent delays, cost overruns, deficient safety, absent quality. The authors have been carrying out several studies whose aiming at are clarify reasons for the lack of competitiveness of national construction industry on the four items mentioned above. This paper occurs mainly about the aims of PhD` survey about construction delays. It has the following mains components: (1) to research and analysis bibliography and establish a common set of causes and background reasons for the problem; (2) to inquire to Portuguese construction stakeholders on the causes and background reasons for project delays following from their experience in recent projects; (3) to establish possible paths to solve the problem. The survey results appear to confirm the original list of causes for delays of the study. The mains reasons are related with designer problems, poor productivity, procurement system, overly optimistic planning, and frequent change orders during construction and so on. Thereafter, the paper will seek what could possibly be done and from which parties, in order to correct the above problems and improve construction competitiveness. The most highly ranked on a scale of relevance by stakeholders were implementation a national database with the quantity works list for different construction projects, a more appropriate and efficient organizational systems within design teams and a need for greater care on the part of the owners when they prepare their schedules and preliminary programmes.Science and Technology Foundation, in Portuguese - Project SAPIENS Nº 4762 "Reasons for the lack of accomplishment of schedule, costs and safety objectives in construction".LEONARDO DA VINCI - Community Vocational Training Action Programme Second, Phase 2000-2006 - Project PL/04/B/P/PP/-174 417 "Recognition of needs and creation of professional training in the area of preparation and management of infrastructure construction projects financed by the European Union"

Modelos de aprendizagem na construção

A importância da consideração do efeito de aprendizagem no planeamento das actividades produtivas industriais tem sido objecto de investigação abundante. Recentemente, com o reconhecimento das vantagens da consideração do fenómeno, a investigação estendeuse também ao sector da construção. No entanto, são conhecidas dificuldades de aplicação do produto dessa análise em especial no tocante ao modelo matemático a adoptar para a curva de aprendizagem. Neste trabalho, faz-se uma descrição dos modelos matemáticos mais utilizados para a modelação da aprendizagem e é apresentado um estudo que aponta para uma melhor correlação do modelo cúbico (logx, y) com a informação conhecida e para uma melhor previsão do modelo linear (logx, logy) de desempenhos futuros