Solving Single-Track Railway Scheduling Problem Using Constraint Programming

The Single Track Railway Scheduling Problem can be modelled as a special case of the Job-Shop Scheduling Problem. This can be achieved by considering the train trips as jobs, which will be scheduled on tracks regarded as resources. A train trip may have many tasks that consist of traversing from one point to another on a track. Each of these distinct points can be a station or a signal placed along the track. Conflicts may occur when the desired timetable would result in two trains occupying the same section of the track at the same time. The mapping of the problem we have proposed in this thesis is a more realistic approach when modelling the physical representation of a track railway. This is because we take into account the actual signals placed along the track delimiting each track segment, avoiding thus the possibility of trains running into each other. Previous authors adopted an approximation to what is found in practice by adding minimum headway constraints between trains into their model. Two strategies for resolving the conflicts in a desired timetable are presented. The two strategies have their applicability in practice. For instance, resolving a conflict in the first strategy stems from the observed practice of train operators: in the first strategy a conflict is resolved by re-timing one of the trips at its departure time up to the point the conflict is resolved. Train operating companies do not typically want to plan for passenger trains being delayed after their departure. On the other hand, the second strategy resolves a conflict by delaying only the conflicting piece of one of the two trips (and subsequent pieces of that trip). In this way, the section of the trip before the conflicting point does not need to be re-timed. This procedure yields solutions with lower total delay. Moreover, with this second strategy, we can also handle the usual practice with passenger trains of not delaying them after their departure, as well as situations in which a train may be delayed along a trip in order to reslove a conflict. Furthermore, we present a group of practical constraints, incorporated into our software to solve the problem, that arise in real-life problems to which little attention has been paid. Using the algorithms developed in this thesis, we are able to solve 21 real-life single-track railway scheduling instances of problems, 19 of them to optimality

Modelling the growth of Salmonella spp. and Escherichia coli O157 on lettuce

This study aimed to model the growth of Salmonella and Escherichia coli O157 on lettuce at different temperatures. Microorganisms were inoculated separately on lettuce and stored at 5, 10, 25, and 37°C. Growth curves were built by fitting the data to the Baranyi’s DMFit model and Ratkowsky equation was used as secondary model. The models were able to assess the growth of both microorganisms and data showed that bacteria did not growth for 24 hours at 10°C, what can be a suitable temperature for lettuce distribution on food services. However, prolonged periods demonstrated growth at every temperatures examined

Curso de Direito Processual Civil

- Divulgação dos SUMÁRIOS das obras recentemente incorporadas ao acervo da Biblioteca Ministro Oscar Saraiva do STJ. Em respeito à Lei de Direitos Autorais, não disponibilizamos a obra na íntegra.- Localização na estante: 347.91/.95(81) O48cd

The effect of forager loss on honeybee workers temporal polyethism and social network structure

The western honeybee Apis mellifera is perhaps the best-known example of an advanced eusocial species displaying temporal polyethism, a process in which workers perform different tasks in the colony as they age. Previous studies demonstrated that this temporal division of labour is not only regulated by the age of the bees but also by the proportion of workers performing the required tasks in the colony. As we progress through the Anthropocene, the Intergovernmental Panel on Climate Change predicted that a significant increase in both the frequency and intensity of severe weather events can be expected in the coming decades. Here, we performed a controlled interrupted time series experiment with the objective of quantifying the possible effects that these weather events might have in the honeybee colony dynamics. By simulating a significant loss of foragers in the colony, we observed that honeybee workers quickly replaced the missing foragers by accelerating their transition to a subsequent task and, in some cases, completely skipped several of the natural task transitions with respect to their age. In addition, we analysed how the colony social network structure is affected by the sudden loss of foragers. Indeed, our data show that honeybee colonies increased their network cohesion with workers having a higher number of interactions as well as becoming more closely connected to one another soon after the disturbance. Overall, our data shows that even when faced with a substantial perturbation, honeybees can respond swiftly in order to maintain colony homeostasis and likely increase their resilience against future perturbations

Identificando necessidades de acervo de usuários de um departamento acadêmico: uma abordagem bibliométrica

A rotina de uma biblioteca universitária de médio para grande porte pode perder de vista os interesses de seus clientes: os usuários. Diante de um aporte de verba, enviam-se memorandos pedindo aos departamentos da instituição listas de itens que gostariam de ver adquiridos. Muitas vezes, os membros do departamento são pegos de surpresa e suas listas são feitas às pressas. Este trabalho apresenta uma medotologia para um sistema interativo de sugestões aos usuários para facilitar a aquisição. Tais sugestões se basearão nos indicativos de necessidades dos próprios usuários, em seus trabalhos científicos. Para a validação inicial, realizou-se experimento em um departamento universitário utilizando a metodologia proposta, na qual acertamos mais de 41% dos itens desejados pelos membros do departamento em estudo

O trabalho do acadêmico de enfermagem como fator de risco para o consumo de álcool e outras drogas

This descriptive, qualitative study aims to describe risk factors, in the work environment, for the consumption of alcohol and other drugs, and also to confirm the importance of protective factors. Interview technique was used with 51 nursing students at the Rio de Janeiro State University, who work in the city's health services. RESULTS: students related work as a risk factor for the consumption of drugs such as alcohol, cigarettes and anxiolytics. We conclude that working with participative methodologies, valuing student's former experiences, family and group life, and individual characteristics are essential in the preventive approach. Attention to protective factors is recommended.Estudio cualitativo descriptivo que tuvo por objetivo describir los factores de riesgo dentro del ambiente laboral para el consumo de alcohol y otras drogas; así como confirmar la importancia de factores de protección. Se utilizó la técnica de entrevista con 51 estudiantes de enfermería de la Universidad del Estado de Río de Janeiro, que se encontraban en los servicios de salud de la ciudad. RESULTADOS: los alumnos consideraron al trabajo como un factor de riesgo para el consumo de alcohol, cigarro y ansiolíticos. Se concluyó que se debe trabajar en la prevención con métodos participativos y valorar las experiencias pasadas de los alumnos, la convivencia familiar y grupal y las características individuales. Fue recomendada especial atención a los factores de protección.Estudo qualitativo descritivo que objetivou descrever os fatores de risco no ambiente de trabalho para o consumo de álcool e outras drogas, e também ratificar a importância dos fatores protetores. Utilizou-se entrevista com roteiro em 51 acadêmicos de enfermagem da Universidade do Estado do Rio de Janeiro que atuam nos serviços de saúde do município. RESULTADOS: os alunos referiram ao trabalho como fator de risco para o consumo de drogas como o álcool, cigarro e ansiolíticos. Concluiu-se que na abordagem da prevenção, deve-se trabalhar com metodologias participativas e valorizar as experiências pregressas dos alunos, o convívio familiar e grupal, e as características individuais. Recomenda-se atenção aos fatores protetores