Managing Rentals with Usage-Based Loss

Motivated by new and innovative rental business models, this paper develops a novel discrete-time model of a rental operation with random loss of inventory due to customer use. The inventory level is chosen before the start of a finite rental season, and customers not immediately served are lost. Our analysis framework uses stochastic comparisons of sample paths to derive structural results that hold under good generality for demands, rental durations, and rental unit lifetimes. Considering different \recirculation" rules | i.e., which rental unit to choose to meet each demand | we prove the concavity of the expected profit function and identify the optimal recirculation rule. A numerical study clarifies when considering rental unit loss and recirculation rules matters most for the inventory decision: Accounting for rental unit loss can increase the expected profit by 7% for a single season and becomes even more important as the time horizon lengthens. We also observe that the optimal inventory level in response to increasing loss probability is non-monotonic. Finally, we show that choosing the optimal recirculation rule over another simple policy allows more rental units to be profitably added, and the profit-maximizing service level increases by up to 6 percentage points.

The Views of Young People about an Intervention Programme Designed to Support Them with Exam Related Anxiety and Stress

Both preparing for and sitting exams can be extremely stressful for children and young people. Whilst the research within the area of exam anxiety acknowledges the detrimental impact that it can have on individuals, much of the research has been completed with university students. Limited research has been carried out with children and young people. In addition to this, there is also little research that has been completed in order to understand which interventions are helpful in reducing exam anxiety in young people. The systematic literature review highlighted that much of the research employed quantitative techniques. This means young people’s views and experiences of exam anxiety has largely been unexplored. The EPS service in which the TEP currently works is a partially traded service. Some of the schools that had bought a service level agreement requested support for certain pupils that were experiencing exam anxiety. The EPS service therefore delivered an intervention called ‘beating exam anxiety together’ (further details of this intervention can be found within chapter 1). Seven semi-structured interviews were carried out with GCSE students who took part in the ‘beating exam anxiety together’ intervention. The purpose of the interviews was to understand more about young people’s views on exam anxiety, and also their experiences of the intervention in which they took part. The research highlighted the possible detrimental impact of exam anxiety on young people in terms of their mental health, and also how able they feel to prepare for their exams. The results of the research interestingly showed that young people experience high levels of pressure from school teachers and also their parents. Furthermore, students reported that they didn't know how to revise. The results revealed that young people feel that the way in which exams are spoken about in schools is largely negative. As a result of this, the researcher suggested that it may be helpful to shift the narrative around the way in which exams are currently spoken about. In addition to this, the results indicate that the intervention was largely helpful in improving young people’s well being and their ability to be able to manage exam anxiety.

Pico Cell Integration to Operator’s Incident Management Process

Mobile network coverage is traditionally provided by outdoor macro base stations, which have a long range and serve several of customers. Due to modern passive houses and tightening construction legislation, mobile network service is deteriorated in many indoor locations. Typically, solutions for indoor coverage problem are expensive and demand actions from the mobile operator. Due to these, superior solutions are constantly researched. The solution presented in this thesis is based on Small Cell technology. Small Cells are low power access nodes designed to provide voice and data services.. This thesis concentrates on a specific Small Cell solution, which is called a Pico Cell. The problem regarding Pico Cells and Small Cells in general is that they are a new technological solution for the mobile operator, and the possible problem sources and incidents are not properly mapped. The purpose of this thesis is to figure out the possible problems in the Pico Cell deployment and how they could be solved within the operator’s incident management process. The research in the thesis is carried out with a literature research and a case study. The possible problems are investigated through lab testing. Pico Cell automated deployment process was tested in the lab environment and its proper functionality is confirmed. The related network elements were also tested and examined, and the emerged problems are resolvable. Operators existing incident management process can be used for Pico Cell troubleshooting with minor updates. Certain pre-requirements have to be met before Pico Cell deployment can be considered. The main contribution of this thesis is the Pico Cell integrated incident management process. The presented solution works in theory and solves the problems found during the lab testing. The limitations in the customer service level were solved by adding the necessary tools and by designing a working question pattern. Process structures for automated network discovery and pico specific radio parameter planning were also added for the mobile network management layer..

Stratégie de gestion de stocks dans un réseau collaboratif

Le contenu de ce mémoire traite du problème de gestion des stocks dans un réseau constitué de plusieurs sites de stockage de produits. Chaque site i gère son stock de manière autonome pour satisfaire une demande déterministe sur un horizon donné. Un stock maximum Si est tenu à chaque site i. Lorsque le point de commande si est atteint, une commande de taille Qi est placée au centre de distribution qui alimente tous les sites. Qi est telle que Qi = Si - si. La quantité Qi est livrée dans un délai connu Li. Si, à un instant donné, la demande Di au site i excède la quantité en main, le site i fait appel à un ou à plusieurs autres sites du réseau pour le transfert d’une quantité Xji (j = 1, 2, …, n). Ce transfert s’effectue selon un certain nombre de règles de jeu qui tiennent compte des coûts de transfert, de stockage, d’approvisionnement et de pénurie. Ce mémoire examine six principales contributions publiées dans la littérature pour évaluer les contributions d’un modèle collaboratif aux performances, en termes de coûts et de niveau de service, de chaque site du réseau. Cette investigation se limite à une configuration du réseau à deux échelons : un entrepôt central et n (n > 2) sites de stockage. Le cas des pièces de rechange, caractérisé par une demande aléatoire, est examiné dans trois chapitres de ce mémoire. Une autre application de ces stratégies à la collaboration entre n centres hospitaliers (n > 2) est également examinée dans ce travail.

The Warwick-Edinburgh Mental Well-Being Scale

Background There is increasing international interest in the concept of mental well-being and its contribution to all aspects of human life. Demand for instruments to monitor mental well-being at a population level and evaluate mental health promotion initiatives is growing. This article describes the development and validation of a new scale, comprised only of positively worded items relating to different aspects of positive mental health: the Warwick-Edinburgh Mental Well-Being Scale (WEMWBS). Methods WEMWBS was developed by an expert panel drawing on current academic literature, qualitative research with focus groups, and psychometric testing of an existing scale. It was validated on a student and representative population sample. Content validity was assessed by reviewing the frequency of complete responses and the distribution of responses to each item. Confirmatory factor analysis was used to test the hypothesis that the scale measured a single construct. Internal consistency was assessed using Cronbach’s alpha. Criterion validity was explored in terms of correlations between WEMWBS and other scales and by testing whether the scale discriminated between population groups in line with pre-specified hypotheses. Test-retest reliability was assessed at one week using intra-class correlation coefficients. Susceptibility to bias was measured using the Balanced Inventory of Desired Responding. Results WEMWBS showed good content validity. Confirmatory factor analysis supported the single factor hypothesis. A Cronbach’s alpha score of 0.89 (student sample) and 0.91 (population sample) suggests some item redundancy in the scale. WEMWBS showed high correlations with other mental health and well-being scales and lower correlations with scales measuring overall health. Its distribution was near normal and the scale did not show ceiling effects in a population sample. It discriminated between population groups in a way that is largely consistent with the results of other population surveys. Test–retest reliability at one week was high (0.83). Social desirability bias was lower or similar to that of other comparable scales. Conclusions WEMWBS is a measure of mental well-being focusing entirely on positive aspects of mental health. As a short and psychometrically robust scale, with no ceiling effects in a population sample, it offers promise as a tool for monitoring mental well-being at a population level. Whilst WEMWBS should appeal to those evaluating mental health promotion initiatives, it is important that the scale’s sensitivity to change is established before it is recommended in this context.

Carrier Selection for Multi-commodity Flow Optimization in Cooperative Environments

Part 18: Optimization in Collaborative Networks

Asociaciones público privadas para la infraestructura social en salud: hacia la identificación de pautas para la definición de un modelo colombiano

Las asociaciones público privadas "APP" han sido utilizadas para distribuir riesgos y fomentar el desarrollo de los países a través de la provisión de infraestructura. Así, se implementan para proveer bienes y servicios públicos tanto en los sectores de infraestructura productiva (carreteras, puertos, aeropuertos, trenes), como en el sector de infraestructura social (escuelas, universidades, hospitales, edificaciones públicas, etc.). En Colombia, ante la escasez de recursos públicos y la necesidad de formular posiibles soluciones a la crisis del sector salud, surge como una posible solución el modelo de APP consagrado en la Ley 1508 de 2008.

Radio frequency communication and fault detection for railway signalling

The continuous and swift progression of both wireless and wired communication technologies in today's world owes its success to the foundational systems established earlier. These systems serve as the building blocks that enable the enhancement of services to cater to evolving requirements. Studying the vulnerabilities of previously designed systems and their current usage leads to the development of new communication technologies replacing the old ones such as GSM-R in the railway field. The current industrial research has a specific focus on finding an appropriate telecommunication solution for railway communications that will replace the GSM-R standard which will be switched off in the next years. Various standardization organizations are currently exploring and designing a radiofrequency technology based standard solution to serve railway communications in the form of FRMCS (Future Railway Mobile Communication System) to substitute the current GSM-R. Bearing on this topic, the primary strategic objective of the research is to assess the feasibility to leverage on the current public network technologies such as LTE to cater to mission and safety critical communication for low density lines. The research aims to identify the constraints, define a service level agreement with telecom operators, and establish the necessary implementations to make the system as reliable as possible over an open and public network, while considering safety and cybersecurity aspects. The LTE infrastructure would be utilized to transmit the vital data for the communication of a railway system and to gather and transmit all the field measurements to the control room for maintenance purposes. Given the significance of maintenance activities in the railway sector, the ongoing research includes the implementation of a machine learning algorithm to detect railway equipment faults, reducing time and human analysis errors due to the large volume of measurements from the field.

An Italian job: the need for collective wage bargaining reform. Bruegel Policy Brief ISSUE 2016/11 - JULY 2016

Highlights: Since the mid-1990s, Italy has been characterised by a lack of labour productivity growth, combinedwith a 60 percent growth in labour costs, 20 percentage points above euro-area average consumer price growth. As a consequence, Italy has become less competitive compared to its euro-area partners, the profitability of its firms has dropped and real GDP-per-capita has flatlined. • At the root of the substantial discrepancy between wages and productivity is Italy’s system of centralised wage bargaining which, in many ways, is designed without regard for the underlying industrial structure and geographical heterogeneity of the Italian economy.This has fostered perverse incentives and imbalances within Italy. • Collective wage bargaining, and in particular the determination of base salaries, should be moved from the national to the regional level for all contracts, in the public and private sectors.The Mezzogiorno,which might superficially be seen as losing out from this policy, would actually gain the most in competitiveness terms. • Furthermore, measures should be taken so that, in the long run, the Italian industrial structure evolves into a less fragmented small-company-based economy. This firm consolidation would likely expand the use of firm-level agreements and performance payments, and would improve Italy’s productivity and competitiveness overall.

Level monitoring system for waste oil containers: an EPS@ISEP project

Waste oil recycling companies play a very important role in our society. Competition among companies is tough and process optimization is essential for survival. By equipping oil containers with a level monitoring system that periodically reports the level and alerts when it reaches the preset threshold, the oil recycling companies are able to streamline the oil collection process and, thus, reduce the operation costs while maintaining the quality of service. This paper describes the development of this level monitoring system by a team of four students from different engineering backgrounds and nationalities. The team conducted a study of the state of the art, draw marketing and sustainable development plans and, finally, designed and implemented a prototype that continuously measures the container content level and sends an alert message as soon as it reaches the preset capacity.

Service-oriented mobility of java code in web services-based architectures

Dissertação apresentada na Faculdade de Ciências e Tecnologias da Universidade Nova de Lisboa para a obtenção do Grau de Mestre em Engenharia Informática

A middleware for service oriented computing in dynamic environments

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para a obtenção do Grau de Mestre em Engenharia Informática

Heterogeneous sensor database framework for the sensor observation service: integrating remote and in-situ sensor observations at the database backend

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Service-oriented infrastructure to support the control, monitoring and management of a shop floor system

Dissertação para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores