489 research outputs found
A multi-objective model for a multi-period distribution management problem
The problems arising in commercial distribution are complex and involve several players and decision levels. One important decision is related with the design of the routes to distribute the products, in an efficient and inexpensive way. This article deals with a complex vehicle routing problem that can be seen as a new extension of the basic vehicle routing problem. The proposed model is a multi-objective combinatorial optimization problem that considers three objectives and multiple periods, which models in a closer way the real distribution problems. The first objective is cost minimization, the second is balancing work levels and the third is a marketing objective. An application of the model on a small example, with 5 clients and 3 days, is presented. The results of the model show the complexity of solving multi-objective combinatorial optimization problems and the contradiction between the several distribution management objective.Distribution problem, multi-objective models
Inventory-routing model, for a multi-period problem with stochastic and deterministic demand
The need for integration in the supply chain management leads us to consider the coordination of two logistic planning functions: transportation and inventory. The coordination of these activities can be an extremely important source of competitive advantage in the supply chain management. The battle for cost reduction can pass through the equilibrium of transportation versus inventory managing costs. In this work, we study the specific case of an inventory-routing problem for a week planning period with different types of demand. A heuristic methodology, based on the Iterated Local Search, is proposed to solve the Multi-Period Inventory Routing Problem with stochastic and deterministic demand.Inventory-Routing, iterated local search, logistics
Driver scheduling problem modelling
The Drivers Scheduling Problem (DSP) consists of selecting a set of duties for vehicle drivers, for example buses, trains, plane or boat drivers or pilots, for the transportation of passengers or goods. This is a complex problem because it involves several constraints related to labour and company rules and can also present different evaluation criteria and objectives. Being able to develop an adequate model for this problem that can represent the real problem as close as possible is an important research area.The main objective of this research work is to present new mathematical models to the DSP problem that represent all the complexity of the drivers scheduling problem, and also demonstrate that the solutions of these models can be easily implemented in real situations. This issue has been recognized by several authors and as important problem in Public Transportation. The most well-known and general formulation for the DSP is a Set Partition/Set Covering Model (SPP/SCP). However, to a large extend these models simplify some of the specific business aspects and issues of real problems. This makes it difficult to use these models as automatic planning systems because the schedules obtained must be modified manually to be implemented in real situations. Based on extensive passenger transportation experience in bus companies in Portugal, we propose new alternative models to formulate the DSP problem. These models are also based on Set Partitioning/Covering Models; however, they take into account the bus operator issues and the perspective opinions and environment of the user.We follow the steps of the Operations Research Methodology which consist of: Identify the Problem; Understand the System; Formulate a Mathematical Model; Verify the Model; Select the Best Alternative; Present the Results of the Analysis and Implement and Evaluate. All the processes are done with close participation and involvement of the final users from different transportation companies. The plannerâs opinion and main criticisms are used to improve the proposed model in a continuous enrichment process. The final objective is to have a model that can be incorporated into an information system to be used as an automatic tool to produce driver schedules. Therefore, the criteria for evaluating the models is the capacity to generate real and useful schedules that can be implemented without many manual adjustments or modifications. We have considered the following as measures of the quality of the model: simplicity, solution quality and applicability. We tested the alternative models with a set of real data obtained from several different transportation companies and analyzed the optimal schedules obtained with respect to the applicability of the solution to the real situation. To do this, the schedules were analyzed by the planners to determine their quality and applicability. The main result of this work is the proposition of new mathematical models for the DSP that better represent the realities of the passenger transportation operators and lead to better schedules that can be implemented directly in real situations.Drivers Scheduling Problem, Duties, Modelling
How to turn innovative startups into successful businesses: The case of Techperks
The Internet of Things, also known by the acronym IoT, comprises all devices and objects that are enabled to be permanently connected to the Internet, being able to identify on the network and communicate with each other. This technology is incorporated into a variety of products that are available today and designed to make life easier for consumers. The result was the emergence of smart cities, connected factories, connected cars, and an enormous amount of many other applications. All of this is evidence of how the world is adapting to the Internet of Things (IoT). IoT is a hot topic in our days and many business models arise from this trend, in form of new technologies, products, and services. However, when it comes to business strategy and profitability, it is not only about having the best idea or the best product but how to market it in the best way and attract the right target. Techperks is a startup built with the objective of bringing new IoT products to Portugal. However, the concept was not innovative enough to succeed as predicted in the Portuguese market. This case aims to highlight the biggest reasons explaining the brand's low performance and serve as a guide of âmistakes to avoid when launching a new innovative businessâ. It can also be used to stimulate studentâs creativity in developing strategies used by Techperks to exploit the brand's total potential. âHow should I begin?â: this is the question which students will be able to answer.A Internet das Coisas, tambĂ©m conhecida pelo acrĂłnimo IoT, compreende todos os dispositivos e objetos que se conectam permanentemente Ă Internet, e que comunicam entre si. DaĂ, surgiram cidades inteligentes, fĂĄbricas conectadas, carros conectados e um sem nĂșmero de outras aplicaçÔes que nos trazem, todos os dias, novas funcionalidades. Este Ă© um tĂłpico muito relevante e muitos novos modelos de negĂłcios surgem dessa nova tendĂȘncia, sob forma de novas tecnologias, produtos e serviços. Espera-se que muitos provavelmente tenham sucesso, dado o crescimento desta nova era da tecnologia. No entanto, quando se trata de estratĂ©gia de negĂłcios e lucro, nĂŁo se trata apenas de ter a melhor ideia ou o melhor produto, mas tambĂ©m como comercializĂĄ-lo da melhor maneira e atrair o alvo mais atrativo. A startup Techperks foi criada com vista a trazer novos produtos de IoT para Portugal, atravĂ©s da sua revenda. No entanto, o conceito nĂŁo foi inovador o suficiente para criar sucesso no mercado portuguĂȘs e a startup nĂŁo conseguiu instigar sua visĂŁo no mercado. Embora ainda em operação, a loja tem demonstrado resultados aquĂ©m das previsĂ”es. Este caso, tem como objetivo destacar os principais motivos que explicam o fraca performance da marca e servir como um guia para "os erros a serem evitados ao iniciar um novo negĂłcio retalhista inovador". AlĂ©m disso, pode ser utilizado para estimular a criatividade dos alunos no desenvolvimento de estratĂ©gias que poderiam ter sido usadas pela Techperks para evitar o insucesso e utilizar todo o potencial da marca
Challenges in the conservation of historical chemicals: Corrosion patterns in glass containers and development of preservation guidelines
Collections of chemicals are assemblies of substances associated to chemical operations. These collections often have a large historical significance and can be found in departments, research institutions, schools or other spaces. So far, seldom dedicated studies have been made, both to the materiality of these collections, as well as for their conservation. For this dissertation, the glass containers in the collection of historical chemicals from the National Museum of Natural History and Science from the University of Lisbon (MUHNAC) are studied, as they are the largest storage material found in the collection and present signs of active deterioration, in the form of corrosion patterns. This research followed a three-fold approach â a collection survey was performed to assess the collectionâs dimension; followed by a full conservation assessment of the corrosion patterns, collection locations and environmental conditions and the establishment of the conservation condition for the collectionsâ glasses. Lastly, an analytical approach was taken. Glass surface measurements indicate the alkalinisation of the glasses, as a sign of active corrosion. Through the use of in situ p-XRF analyses, glass chemical composition groups are correspondent with soda-lime-silicate glasses. Samples of aqueous chemical solutions were also collected and analysed through ICP-AES and HPIC with the goal to determine if the chemicals matched the containersâ labels and if they may present glass dissolution products. One of the outcomes of this dissertation is the development of preservation guidelines, through the empirical and analytical data gathered from the study of the MUHNACâs collection, as well as the results of a survey addressed to similar institutions holding historical collections of chemicals. The final result is the proposal of guidelines that outline selection criteria for chemicals, tools and measures for collectionsâ care to objects and actions for collectionsâ keepers. It is intended that these guidelines may aid small and large institutions in the preservation of their collections
~ 610 Ma: a critical age for the Iberian consolidation
AIMS OF THE MEETING: The scientific sessions will be focused on the Pan-African and Cadomian Orogenies recorded in North Africa and western Europe across the Ediacaran Cambrian transition and its bearing in the assembly and demise of Pannotia. Contributions dealing with structural, magmatic, provenance sources, palaeomagnetic, sedimentary, chronostratigraphic and radiometric constraints are particularly welcome. ORGANIZING COMMITTEE: J. Javier Ălvaro, Instituto de Geociencias (CSIC-UCM), Spain Martim Chichorro, Universidade Nova de Lisboa, Portugal Gabriel GutiĂ©rrez-Alonso, Universidad de Salamanca, Spain.ABSTRACT: Both the Pan-African orogenic cycle and the peri-Gondwanan Cadomian Orogeny took part in
the global tectonic event that led to the rearrangement of Gondwana's west-northern block. An
approach to determine the nature of Cadomian - Pan-African events using detrital zircons
population from Neoproterozoic-Lower Paleozoic (rift-to-drift cycle) stratigraphic record in
Iberian Massif is here discussed.info:eu-repo/semantics/publishedVersio
Portuguese regional differences in the wine grapes mycoflora
The recent discovery of mycotoxins in wine, in particular ochratoxin A, caused
concern and motivated an extensive survey to the mycoflora of Portuguese
grapes. It is known that the mycoflora of agricultural commodities can vary
according to the geographical origin, and therefore, regional differences in the
mycoflora of Portuguese were investigated. Four regions were selected for a 3-
year study: Alentejo, Douro, Ribatejo and Vinhos Verdes. The mycoflora of grapes
was evaluated by plating methods. A total of 32 grape samples were taken, of 50
berries each. The differences in the mycoflora of grapes between regions were
analyzed using the non-parametric test Kruskal-Wallis H. Ostensibly, the
classification of the grapes into their geographical origin based on its mycoflora
was attempted using a decision tree algorithm (C4.5) based on the Shannon
Information Theory. Of the 27 fungal genera identified, 3 varied its incidence
significantly according to the region of origin of the samples: Aspergillus, Botrytis
and Ulocladium. The only species that varied significantly its frequency between
regions was A. niger aggregate. Six Penicillium species differed significantly
between regions: P. brevicompactum, P. citrinum, P. glabrum/spinulosum, P.
expansum, P. implicatum and P. thomii. Using decision trees it was possible to
classify successfully 91% of the samples according to 3 sample classes: Vinhos
Verdes, Douro and South samples (Alentejo and Ribatejo). The classification was
based on the incidence of A. niger and P. thomii in the grape samples. The
estimated predictive ability of the model in the 3 classes was 82%.
The data presented here indicate that grapes are consistently exposed to a
particular mycoflora that varies according its geographical origin, which may be of
importance to establishing risk areas for mycotoxin contamination of grapes and
wine.Economic Community (EC) - Quality of Life Program (QoL), Key Action 1 (KA1) on Food, Nutrition and Health - contract number QLK1-CT-2001-01761 - Wine-Ochra Risk
Acessibilidade Ă rede de serviços de urgĂȘncia: o caso do Baixo Alentejo
O acesso aos cuidados de saĂșde Ă© um conceito complexo, que compreende vĂĄrias dimensĂ”es, uma das quais a acessibilidade. Na perspetiva que aqui se propĂ”e analisar, a acessibilidade relaciona-se essencialmente com a localização e distribuição geogrĂĄfica dos serviços e dos utilizadores. A presente dissertação pretende assim constituir uma reflexĂŁo sobre esta dimensĂŁo, aplicada Ă rede de serviços de urgĂȘncia (SU) do Baixo Alentejo.
O ponto de partida Ă© o de que, envolvendo a nova estrutura do Sistema Integrado de EmergĂȘncia MĂ©dica (SIEM) ao nĂvel da responsabilidade hospitalar e prĂ©-hospitalar, a que faz menção o Despacho n.Âș 10319/2014, de 11 de agosto, nĂŁo se identificam novos trabalhos, nem relatĂłrios de monitorização sobre a acessibilidade da população a estes serviços. Contudo, Ă© uma temĂĄtica que tem merecido destaque quer na opiniĂŁo pĂșblica, quer no debate polĂtico. SĂŁo vĂĄrias as notĂcias que dĂŁo conta de serviços encerrados, falta de recursos humanos e equipamentos, necessidade de construção de novas unidades, entre outras. Por outro lado, as polĂticas definidas sĂŁo sobretudo ao nĂvel comunitĂĄrio e nacional, nĂŁo existindo um acompanhamento e concretização das mesmas ao nĂvel regional e local.
Nesta medida, recorreu-se a uma ferramenta de anĂĄlise de redes, a network analyst (ESRI), para a elaboração de Ăndices de acessibilidade atravĂ©s do algoritmo service areas. Optou-se ainda por incluir algumas informaçÔes estatĂsticas relativas Ă população residente, mas tambĂ©m referentes aos prĂłprios serviços de urgĂȘncia e meios de emergĂȘncia do INEM, por exemplo, horĂĄrios de funcionamento, existĂȘncia ou nĂŁo existĂȘncia de meios complementares de diagnĂłstico e terapĂȘutica, entre outros.
Os resultados alcançados permitem verificar que a acessibilidade Ă©, na generalidade, satisfatĂłria quando incluĂdos os trĂȘs serviços de urgĂȘncia existentes na ĂĄrea de estudo, mas diminui consideravelmente se for admitido apenas o serviço de urgĂȘncia mĂ©dico-cirĂșrgico do Hospital de Beja, excluindo assim os dois serviços de urgĂȘncia bĂĄsico, destinados a resolver as situaçÔes mais simples e comuns. Foram tambĂ©m calculados outros Ăndices que, como se verĂĄ, permitiram o cruzamento da distĂąncia-tempo entre os serviços e os meios de transporte existentes.
Ainda assim, haverĂĄ que refletir sobre a população que Ă© caraterizada com menores Ăndices de acessibilidade, mais idosa e residente em zonas com baixa densidade populacional, e Ă qual se associam com mais frequĂȘncia patologias incapacitantes como Ă© o caso de AVCâs, diabetes, enfartes, entre outros, razĂŁo pela qual deverĂĄ existir uma rĂĄpida capacidade de resposta e ação dos meios de emergĂȘncia/urgĂȘncia.Access to health care is a complex concept, which comprises several dimensions, including accessibility. In the perspective that it is proposed here to analyze, accessibility is essentially related to the location and geographical distribution of services and users. The present dissertation intends to constitute a reflection on this dimension, applied to the network of urgency services of Baixo Alentejo.
It starts out from the idea that, involving the new structure of the Integrated Medical Emergency System (SIEM) at the level of hospital and prehospital responsibility, which refers to order no. 10319/2014, of august 11, there are no new work or monitoring reports on the accessibility of the population to these services. However, it is a theme that has been well-known in public opinion and political debate. There are several news that closed account services, lack of human resources and equipment, the need for construction of new units, among others. On the other hand, the policies defined are mainly at Community and national level, and there is no monitoring and implementation at regional and local level.
In this sense, we used a network analysis tool, the network analyst (ESRI), for the elaboration of accessibility indexes through the algorithm service areas. It was also decided to include some statistical information on the resident population, but also on INEM's own emergency services and emergency facilities, such as hours of operation, existence or non-existence of complementary diagnostic and therapeutic means, among others.
The results show that accessibility is generally satisfactory when analyzing the three existing emergency services in the area of study. However, there is a considerable decrease if we only consider the medical and surgical emergency service of the Hospital de Beja, excluding the two basic emergency services, designed to solve the most simple and common situations. Other indexes were calculated which, as will be seen, allowed the crossing of the distance-time between the services and the existing means of transport.
Nevertheless, it will be necessary to reflect on the population that is characterized by lower levels of accessibility, older and residing in areas with low population density, which are associated more frequently with incapacitating pathologies such as stroke, diabetes, heart attacks, others, which is why there must be a rapid response and emergency/urgency response capability
As representaçÔes dos progenitores acerca da relação com os seus próprios pais e mães na sua infùncia e a sua importùncia na vinculação ao bebé
Tese de mestrado, Psicologia (Secção de Psicologia ClĂnica e da SaĂșde, NĂșcleo de Psicologia ClĂnica DinĂąmica), Universidade de Lisboa, Faculdade de Psicologia, 2016Os cuidados que os indivĂduos receberam dos seus pais na infĂąncia influenciam o seu desenvolvimento, uma vez que determinam a organização dos seus modelos internos de funcionamento e do seu padrĂŁo de vinculação, orientando o seu comportamento e as suas relaçÔes interpessoais ao longo da vida (Bowlby, 1973, 1982). Se as representaçÔes internas influenciam a relação dos pais com os seus filhos e o comportamento parental, Ă© possĂvel haver uma transmissĂŁo intergeracional da parentalidade. A vinculação parental consiste nos sentimentos que os pais nutrem pelos filhos, determinando a forma como cuidam deles.
Este estudo pretende investigar as representaçÔes que os progenitores tĂȘm acerca da relação com as suas mĂŁes e pais na infĂąncia e a sua importĂąncia na vinculação aos seus filhos com seis a doze meses de idade.
MĂŁes (n = 25) e pais (n = 11) responderam a quatro questionĂĄrios, QuestionĂĄrio SociodemogrĂĄfico e ClĂnico, Parental Bonding Instrument (Parker, Tupling, & Brown, 1979), Escala de Satisfação com o Suporte Social (Ribeiro, 1999), Escala de Avaliação da Satisfação em Ăreas da Vida Conjugal (Narciso & Costa, 1996), alĂ©m da Escala de Vinculação Materna PĂłs-natal (Condon & Corkindale, 1998) sĂł para mĂŁes e da Escala de Vinculação Paterna PĂłs-natal (Condon, Corkindale, & Boyce, 2008) sĂł para pais.
Os resultados indicam que o cuidado percebido pelas mĂŁes na relação com as suas mĂŁes na infĂąncia estĂĄ associado Ă qualidade da vinculação materna pĂłs-natal. Os resultados dos pais serĂŁo apenas um complemento deste estudo, dado o reduzido tamanho desta amostra.The care received by individuals from their parents throughout their childhood will influence their development, because it will determine the organization of their internal working models and their attachment patterns, guiding both their behaviour and personal relationships throughout life (Bowlby, 1973, 1982). If the internal representations influence the parents-children relationship and parental behaviour it is possible to exist an intergenerational transmission of parenting. Parental attachment consists on parentsâ feelings toward their children determining the way parents care of them.
This study intends to investigate parents' representations about their relationships with their mothers and fathers during their childhood ant its' importance for the attachment with their own children between six and twelve months of age.
Mothers (n = 25) and fathers (n = 11) answered four questionaires, Sociodemographic and Clinical Questionnaire, Parental Bonding Instrument (Parker, Tupling, & Brown, 1979), Satisfaction with Social Support Scale (Ribeiro, 1999), Satisfaction in Areas of Marital Life Scale (Narciso & Costa, 1996) as weel as Maternal Post-natal Attachment Scale (Condon & Corkindale, 1998) only for mothers and Paternal Post-natal Attachment Scale (Condon & Corkindale, 2008).
Results indicate that mother's perception about care received from their mothers during childhood is associated to the quality of post-natal maternal attachment. Results regarding the fathers will only be used as a supplement in this study, due to the reduced number of this sample
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