9,954 research outputs found

    Overwash hazard assessment

    Get PDF
    Overwash is a natural storm-related process that occurs when wave runup overcomes the dune crest. Because coastlines are globally occupied, overwash is a hazardous process and there is a need to identify vulnerable areas. This study proposes a method to detect overwash-prone areas in the AncĂŁo peninsula, Portugal, and eventually outlines a vulnerability map. Dune base (DLOW) and crest (DHIGH) topography were surveyed. Three different storm scenarios (5-, 10- and 25- year return period storms) and associated waves and sea level were determined. According to these data, extreme wave runup (RHIGH) was calculated by a parameterisation set for intermediate-reflective beaches. The maps for collision and overwash regimes were designed by comparing RHIGH values with DLOW and DHIGH. Almost the entire dune base along the peninsula is vulnerable to collision regime. The overwash process was identified mainly along the tidal inlet hazard area and within the human-occupied portion of the beach, where overwash is expected to occur within 5 years of return period. The developed method considers the main overwash driving forces and proved to identify hazardous areas previously observed in the area. Occasional differences between modelled and observed overwash areas can be attributable to equipment errors, morphology interpretation subjectivity and maladjustments in runup parameterisation. Nevertheless, the method proved to be effective in reproducing the overall AncĂŁo peninsula vulnerability and can be widely applied. Therefore, it is a simple and potentially important tool for coastal management that enables mitigation strategies for occupied coasts and assessment of geological and ecological consequences in natural areas

    A Multiple Criteria Framework to Evaluate Bank Branch Potential Attractiveness

    Get PDF
    Remarkable progress has occurred over the years in the performance evaluation of bank branches. Even though financial measures are usually considered the most important in assessing branch viability, we posit that insufficient attention has been given to other factors that affect the branches’ potential profitability and attractiveness. Based on the integrated used of cognitive maps and MCDA techniques, we propose a framework that adds value to the way that potential attractiveness criteria to assess bank branches are selected and to the way that the trade-offs between those criteria are obtained. This framework is the result of a process involving several directors from the five largest banks operating in Portugal, and follows a constructivist approach. Our findings suggest that the use of cognitive maps systematically identifies previously omitted criteria that may assess potential attractiveness. The use of MCDA techniques may clarify and add transparency to the way trade-offs are dealt with. Advantages and disadvantages of the proposed framework are also discussed.

    Strategic thinking: The construction and validation of an instrument

    Get PDF
    The lack of instruments that evaluate strategic thinking and the fact that it is positively related to high levels of professional performance has led us to the development and validation of a questionnaire that allows us to measure it in an organizational context. This was done through three studies. First an exploratory study, in which 272 Human Resources (HR) professionals participated, allowed us to develop its items and analyze its psychometric properties. From it three factors were extracted: (1) systemic thinking, (2) vision towards the future and, (3) identification of new opportunities. Also, the results indicated the existence of a latent overall model of strategic thinking. Secondly, a confirmatory study, where 352 Human Resources professionals participated, intended to validate the results of the previous study. The same three factors, and a latent factor were replicated revealing that the model presented had an excellent adjustment. Furthermore, a third study was carried out in order to study the perceived relationship between strategic thinking, satisfaction, trust and customers’ retention. This study counted with the participation of 273 professionals who held positions of middle and upper management, key employees regarding the use of ST in organizations. The results of the three studies allow us to conclude that the Strategic Thinking Questionnaire is a valid instrument to analyze strategic thinking.info:eu-repo/semantics/publishedVersio

    The new automated daily mortality surveillance system

    Get PDF
    The experience reported in an earlier Eurosurveillance issue on a fast method to evaluate the impact of the 2003 heatwave on mortality in Portugal, generated a daily mortality surveillance system (VDM) that has been operating ever since jointly with the Portuguese Heat Health Watch Warning System. This work describes the VDM system and how it evolved to become an automated system operating year-round, and shows briefly its potential using mortality data from January 2006 to June 2009 collected by the system itself. The new system has important advantages such as: rapid information acquisition, completeness (the entire population is included), lightness (very little information is exchanged, date of death, age, sex, place of death registration). It allows rapid detection of impacts (within five days) and allows a quick preliminary quantification of impacts that usually took several years to be done. These characteristics make this system a powerful tool for public health action. The VDM system also represents an example of inter-institutional cooperation, bringing together organisations from two different ministries, Health and Justice, aiming at improving knowledge about the mortality in the population

    Interference suppression with physical-layer network coding and MIMO for multi-way channels

    Get PDF
    Orthogonal techniques (such as TDMA – time division multiple access) are traditionally used when a set of terminals wants to exchange data and a relay is required when wireless terminals cannot communicate directly. This paper proposes two schemes to address multi-way channels when a set of terminals wants to exchange data. Both proposed schemes consist of a first phase based on virtual MIMO with lattice reduction-aided (LRA) detection at the relay, establishing a multiple access channel (MAC). Two new strategies are then proposed for the second (multicast) phase; one for single antenna terminals and another for multiple-input multiple-output (MIMO) terminals. The second strategy achieves interference suppression by successively combining physical layer network coding and MIMO detection (with LRA detectors also at the terminals). The paper assesses a 3 terminals network with a relay for which a TDMA-based scheme would require 6 time-slots, while the proposed strategy for MIMO terminals is able to exchange the information between all terminals using 2 time-slots only. This latter scheme is easily scalable to a higher number of terminals, and always able to accomplish the exchange of messages between all of them in just 2 time-slots, although limited by the number of antennas that the terminals can fit and also the MIMO processing complexity they can afford.info:eu-repo/semantics/acceptedVersio
    • 

    corecore