Telecommunications Network Planning and Maintenance

Telecommunications network operators are on a constant challenge to provide new services which require ubiquitous broadband access. In an attempt to do so, they are faced with many problems such as the network coverage or providing the guaranteed Quality of Service (QoS). Network planning is a multi-objective optimization problem which involves clustering the area of interest by minimizing a cost function which includes relevant parameters, such as installation cost, distance between user and base station, supported traffic, quality of received signal, etc. On the other hand, service assurance deals with the disorders that occur in hardware or software of the managed network. This paper presents a large number of multicriteria techniques that have been developed to deal with different kinds of problems regarding network planning and service assurance. The state of the art presented will help the reader to develop a broader understanding of the problems in the domain

Bayesian Network Analysis for Diagnostics and Prognostics of Engineering Systems

Bayesian networks have been applied to many different domains to perform prognostics, reduce risk and ultimately improve decision making. However, these methods have not been applied to military field and human performance data sets in an industrial environment. Methods frequently rely on a clear understanding of causal connections leading to an undesirable event and detailed understanding of the system behavior. Methods may also require large amount of analyst teams and domain experts, coupled with manual data cleansing and classification. The research performed utilized machine learning algorithms (such as Bayesian networks) and two existing data sets. The primary objective of the research was to develop a diagnostic and prognostic tool utilizing Bayesian networks that does not require the need for detailed causal understanding of the underlying system. The research yielded a predictive method with substantial benefits over reactive methods. The research indicated Bayesian networks can be trained and utilized to predict failure of several important components to include potential malfunction codes and downtime on a real-world Navy data set. The research also considered potential error within the training data set. The results provided credence to utilization of Bayesian networks in real field data – which will always contain error that is not easily quantified. Research should be replicated with additional field data sets from other aircraft. Future research should be conducted to solicit and incorporate domain expertise into subsequent models. Research should also consider incorporation of text based analytics for text fields, which was considered out of scope for this research project

Working Notes from the 1992 AAAI Spring Symposium on Practical Approaches to Scheduling and Planning

The symposium presented issues involved in the development of scheduling systems that can deal with resource and time limitations. To qualify, a system must be implemented and tested to some degree on non-trivial problems (ideally, on real-world problems). However, a system need not be fully deployed to qualify. Systems that schedule actions in terms of metric time constraints typically represent and reason about an external numeric clock or calendar and can be contrasted with those systems that represent time purely symbolically. The following topics are discussed: integrating planning and scheduling; integrating symbolic goals and numerical utilities; managing uncertainty; incremental rescheduling; managing limited computation time; anytime scheduling and planning algorithms, systems; dependency analysis and schedule reuse; management of schedule and plan execution; and incorporation of discrete event techniques

Evolutionary optimization for water losses recognition in water supply networks

A methodology to localise the losses in the water supply networks has been developed, which requires the installation of a number of flowmeters and pressure transducers on the network and the building of a numerical model. The calibration of the model to match the recorded network parameters (pressures and discharges) is done by searching an optimal set of water demands at network nodes. The comparison between the optimal set and the standard one allows the identification of the areas where the leakages are most likely to be present. The optimal set of water demands is identified by the minimisation of an objective function. In the paper, the coupling of this objective function with three evolutionary optimisation methods based on simulated annealing (SA), genetic algorithms (GA) and modified particle swarm optimization (MPSO) have been discussed and tested on a case study. The simulations show SA risks to be trapped in unfeasible zones in its search, while the methods based on GA and MPSO perform very well because in these latter methods, the individuals constituting a population work mainly in groups. Moreover, the solution obtained by GA and MPSO can be further improved by means of a simple hill climbing procedure. Considerations on the possibility of having more than one maximum of the objective function and how they can be detected are presented

A global horizon scan of the future impacts of robotics and autonomous systems on urban ecosystems

Technology is transforming societies worldwide. A significant innovation is the emergence of robotics and autonomous systems (RAS), which have the potential to revolutionise cities for both people and nature. Nonetheless, the opportunities and challenges associated with RAS for urban ecosystems have yet to be considered systematically. Here, we report the findings of an online horizon scan involving 170 expert participants from 35 countries. We conclude that RAS are likely to transform land-use, transport systems and human-nature interactions. The prioritised opportunities were primarily centred on the deployment of RAS for monitoring and management of biodiversity and ecosystems. Fewer challenges were prioritised.Those that were emphasised concerns surrounding waste from unrecovered RAS, and the quality and interpretation of RAS-collected data. Although the future impacts of RAS for urban ecosystems are hard to predict, examining potentially important developments early is essential if we are to avoid detrimental consequences, but fully realise the benefits

A decision support system for the management of smart mobility services

Master Dissertation (Master Degree in Engineering and Management of Information Systems)Nos dias que correm, a mobilidade assume especial importância no quotidiano das áreas metropolitanas em crescimento no país. . Com o notório crescimento das cidades, torna-se necessária e urgente uma transformação dos costumes e formas de mobilidade dentro das áreas urbanas, alterando as realidades aparentes que hoje conhecemos. Inseridos numa sociedade cada vez mais consciencializada e alerta para as questões ambientais, é essencial transportar esta mentalidade renovada para a resolução das problemáticas citadinas. Assim, o conceito de “Cidade Verde” levanta uma série de questões que exigem uma resposta eficaz para o bem-estar dos seus habitantes. Por entre as várias soluções apresentadas para estas patologias, uma das mais promissoras é, sem dúvida, o sistema de mobilidade partilhada. Pela sua dimensão, é pertinente expor o caso prático da cidade de Barcelona, em Espanha, explorando o seu sistema de partilha de scooters, um meio que adquire especial importância como meio de transporte urbano. Como qualquer sistema em constante aprimoramento, procura-se uma solução para a problemática da variação de procura, que apresenta oscilações constantes, tanto a nível temporal como geográfico, resultando na falta de veículos em algumas áreas e excesso noutras. Assim sendo, o rebalanceamento do sistema torna-se crucial para uma possível maximização na utilização de veículos, satisfazendo a procura e potenciando um aumento da sua utilização. No correr desta dissertação, foram estudados e utilizados vários métodos de otimização moderna (metaheurísticas) para a procura de soluções (sub)ótimas para o(s) percurso(s) a percorrer pelo(s) veículo(s) que executam a redistribuição das scooter/bicicletas pelas diversas áreas abrangidas pelo sistema de partilha. Deste modo, foi desenvolvido um sistema de apoio à decisão para satisfazer estas necessidades, garantindo ao utilizador toda a informação relevante para um trabalho mais eficiente e preciso.Nowadays, mobility is especially important in the daily life of the country growing metropolitan areas. With the increasing influx of people and development of these large cities, the reality of mobility that we know becomes increasingly unsustainable. Along with mobility, the environmental concerns are one of the main topics of discussion worldwide and the population is starting to act and change the way they live to find a more “green” and sustainable way of doing it. Several proposals have been put forward, trying to mitigate this issue and, one of the most promising is, undoubtedly, shared mobility systems. In this case study will be addressed the Barcelona scooter sharing system, characterized by its great size and importance as a mean of urban transport. One of the problems presented by these sharing services is that demand varies widely, both temporal and geographical. Thus, there are several cases where there is a lack of vehicles in some areas and an excess in others. The rebalancing of the system is crucial to maximize vehicle utilization and meet customer demand. In this thesis, several modern optimization methods (metaheuristics) were used to search for (sub)optimal solutions for the redistribution route(s). A decision support system was developed to meet this end, giving the end user relevant information for a more efficient and precise work

‘A marvellous order’: how spatial and economic configurations interact to produce agglomeration economies in Greater Manchester

Despite widespread agreement that agglomeration externalities present a powerful economic force, understanding how they work in practice has constituted a “black box” problem. The word “agglomeration” is itself a crude term for describing the spatial characteristics of cities, which disguises the important role that the spatial configuration of street networks plays in structuring the operation of shared supply chains, labour pools, and knowledge-spillovers. At the same time, while most would agree on the importance of economic diversity to urban agglomeration, it is increasingly recognised that this diversity also has relational structure, with certain industry sectors being more likely to interrelate with each other, and share skills, knowledge, and products. This thesis will unpack the role of these spatial and economic configurations in the functioning of Greater Manchester as an “engine of creativity” in the broadest sense. To do so it draws on two main types of network analysis – space syntax analysis (developed by architects) and industry relatedness analysis (developed by economic geographers). This network analysis is contextualised in qualitative and historical research to produce a “thick description” of the city's evolving economy, with an in-depth focus on the clothing, textile, and waterproofing industries. The configurational characteristics of Greater Manchester's street network have brought diverse economic capabilities within reach of each other, while also connecting them into national and international economic flows. A degree of mess and redundancy in the system has been important to spurring unlikely collaborations and new innovations. However, there has been an overall decline in the capacity of the city street network to support agglomeration externalities in recent years, due to a loss of configurational structure and network density that is partly associated with planning changes from the 1950s onwards. The thesis concludes by considering what this means for contemporary policy

Climbing the water ladder: multiple-use water services for poverty reduction

Multiple use / Models / Water productivity / Research projects / Water supply / Domestic water / Irrigation water / Water governance / Poverty / Gender / Rural areas / Wells / Water harvesting / Runoff / Water storage / Water purification / Appropriate technology / Costs / Local government / Non governmental organizations / Case studies / Ehiopia / Nepal / Zimbabwe / Bolivia / India / Colombia / Thailand / South Africa