Hours of work and retirement behavior

Using a novel dataset from the 2006 Portuguese Labor Force Survey this paper examines the impact of a voluntary reduction in hours of work, before retirement, on the moment of exit from the labor force. If, as often suggested, flexibility in hours of work is a useful measure to postpone retirement, then a reduction in working hours should be associated with retirement at later ages. Results prove otherwise suggesting that reducing hours of work before retirement is associated with early exits from the labor force. A reduction in hours of work seems to signal the worker’s wish to retire sooner rather than to announce the desire of remaining in the labor market.aging, retirement, working hours, older workers.

Hours of Work and Retirement Behavior

Using a novel dataset from the 2006 Portuguese Labor Force Survey this paper examines the impact of a voluntary reduction in hours of work, before retirement, on the moment of exit from the labor force. If, as often suggested, flexibility in hours of work is a useful measure to postpone retirement, then a reduction in working hours should be associated with retirement at later ages. Results prove otherwise suggesting that reducing hours of work before retirement is associated with early exits from the labor force. A reduction in hours of work seems to signal the worker's wish to retire sooner rather than to announce the desire of remaining in the labor market. This result may enclose the need for some alternative policy strategies regarding working hours.aging, retirement, working hours, older workers

Age and opportunities for promotion

Using a panel of new firms and their employees, this paper studies the promotion opportunities for older workers within the same firm. Survival analysis suggests that younger employees experience shorter times to promotion than older workers and, therefore, the latter face a smaller likelihood of promotion. Although men are promoted more often than women, empirical results show that women have shorter survival times to promotion than men. Also, previous promotions are stronger determinants of subsequent ones and this finding provides support to the evidence on promotion “fast-tracks”.aging, older workers, employment relationships, promotion

Honey volatiles as a fingerprint for botanical origin: a review on their occurrence on monofloral honeys

Honeys have specific organoleptic characteristics, with nutritional and health benefits, being highly appreciated by consumers, not only in food but also in the pharmaceutical and cosmetic industries. Honey composition varies between regions according to the surrounding flora, enabling its characterization by source or type. Monofloral honeys may reach higher market values than multifloral ones. Honey's aroma is very specific, resulting from the combination of volatile compounds present in low concentrations. The authentication of honey's complex matrix, according to its botanical and/or geographical origin, represents a challenge nowadays, due to the different sorts of adulteration that may occur, leading to the search for reliable marker compounds for the different monofloral honeys. The existing information on the volatiles of monofloral honeys is scarce and disperse. In this review, twenty monofloral honeys and honeydews, from acacia, buckwheat, chestnut, clover, cotton, dandelion, eucalyptus, fir tree, heather, lavender, lime tree, orange, pine, rape, raspberry, rhododendron, rosemary, strawberry tree, sunflower and thyme, were selected for volatile comparison purposes. Taking into consideration the country of origin, the technique of isolation and analysis, the five main volatiles from each of the honeys are compared. Whereas some compounds were found in several types of monofloral honey, and thus not considered good volatile markers, some monofloral honeys revealed characteristic volatile compounds independently of their provenance.Funding: SFRH/BD/117013/2016, UID/AGR/00690/2019, UID/AMB/50017/2019, MED (UIDB/05183/2020), FEDER, PT2020 PACompete 2020info:eu-repo/semantics/publishedVersio

Too-connected-to-fail Institutions and Payments System’s Stability: Assessing Challenges for Financial Authorities

The most recent episode of market turmoil exposed the limitations resulting from the traditional focus on too-big-to-fail institutions within an increasingly systemic-crisis-prone financial system, and encouraged the appearance of the too-connected-to-fail (TCTF) concept. The TCTF concept conveniently broadens the base of potential destabilizing institutions beyond the traditional banking-focused approach to systemic risk, but requires methodologies capable of coping with complex, cross-dependent, context-dependent and non-linear systems. After comprehensively introducing the rise of the TCTF concept, this paper presents a robust, parsimonious and powerful approach to identifying and assessing systemic risk within payments systems, and proposes some analytical routes for assessing financial authorities’ challenges. Banco de la Republica’s approach is based on a convenient mixture of network topology basics for identifying central institutions, and payments systems simulation techniques for quantifying the potential consequences of central institutions failing within Colombian large-value payments systems. Unlike econometrics or network topology alone, results consist of a rich set of quantitative outcomes that capture the complexity, cross-dependency, context-dependency and non-linearity of payments systems, but conveniently disaggregated and dollar-denominated. These outcomes and the proposed analysis provide practical information for enhanced policy and decision-making, where the ability to measure each institution’s contribution to systemic risk may assist financial authorities in their task to achieve payments system’s stability.Payments systems, too-connected-to-fail, too-big-to-fail, systemic risk, network topology, simulation, central bank liquidity. Classification JEL:E58, E44, C63, G21, D85.

Sistemas de comunicação por luz visível aplicados para assistência ao tráfego automóvel

Motivated by the topic of promoting traffic safety applications and information systems, this work aims to bring a study on VLC outdoor application scenarios. The developed topic is part of intelligent transportation systems (ITS) that aim at the delivery of traffic safety and information amongst other safety functions. VLC technology in traffic communication applications gains interest due to some advantages it presents. The use of LEDs in traffic signaling infrastructures and vehicle headlights started to be a growing standard. With the combination of illuminating proprieties and communication in the same device, VLC becomes a very attractive technology for the implementation of outdoor communication systems for traffic information and control. Outdoor VLC channels present variable ambient conditions, with the presence of different optical sources. One major problem in this communication channel is the presence of shot-noise, generated by optical background radiance from different light sources. This dissertation presents two different communication scenarios for traffic information systems, the first being directed at the infrastructure to car (I2C) link and the second one for car to car (C2C) communication. In order to simulate the communication link performance with variable ambient channel conditions, several models for optical propagation, emitter, receiver and noise sources were implemented in MATLAB. Models for different optical sources were also implemented, with field measurements on the illuminance incident on a photo detector and their impact on the noise generated. In the simulation’s performance of the VLC link, several baseband modulation schemes were considered, aiming at the assessment of link performance, based on the traditional digital modulation performance metrics.Motivado em promover o tópico de segurança rodoviária e sistemas de informação, este trabalho providência um estudo dedicado a sistemas de comunicação por luz visível (VLC) para aplicação em cenários de exterior. O tópico desenvolvido faz parte de sistemas de transporte inteligentes (ITS) cujo propósito é a disseminação de sistemas de segurança no tráfego e transferência de informação, para aplicações de segurança. A tecnologia VLC aplicada a sistemas de comunicação de tráfego rodoviário suscita elevado interesse devido a vantagens que esta apresenta. O uso de LED’s em semáforos e faróis de carros começa a ser bastante comum. Com a combinação de diferentes valências, como iluminação e transferência de dados no mesmo dispositivo, a tecnologia VLC torna-se muito atrativa para a implementação em sistema de comunicação exterior dedicados a sistemas de informação e controlo de tráfego. O canal de comunicação VLC exterior apresenta condições variáveis, devido ao fato de existirem condições ambientais diferentes. Um grave problema neste tipo de canal de comunicação é a presença de ruido Shot, que é normalmente gerado devido á radiância causada por diferentes fontes de luz de fundo. Nesta dissertação estão presentes dois tipos de cenários para sistemas de informação de tráfego, em que o primeiro dedica-se á comunicação semáforo-carro (I2C) e o segundo cenário para a comunicação entre carros (C2C). Para simular o desempenho do canal de comunicação com diferentes condições ambientais, foram implementados em MATLAB modelos para a propagação ótica, descrição do emissor, recetor e fontes de ruido. Também foram incluídos modelos para diferentes fontes óticas de radiação, com medições de campo da iluminância incidente num foto recetor e modulado o impacto na geração de ruido. Nas simulações de desempenho da comunicação por luz visível, foram considerados diferentes esquemas de modulação da informação com o intuito de avaliar o desempenho da ligação, a qual foi feita recorrendo a métricas clássicas de desempenho de modulações digitais.Mestrado em Engenharia Eletrónica e Telecomunicaçõe

Development of Non-Destructive Testing by Eddy Currents for Highly Demanding Engineering Applications

Defect detection with Non-Destructive Testing (NDT) is essential in accidents prevention, requiring R&TD to generate new scientific and procedural knowledge for new products with high safety requirements. A current challenge lies in the detection of surface and sub-surface micro defects with NDT by Eddy Currents (EC). The main objective of this work was the development of applied research, technological innovation and experimental validation of EC customized systems for three highly demanding inspection scenarios: micro defects in tubular geometries; brazed joints for the automotive industry; and high-speed moving composite materials. This objective implied starting from the scientific fundamentals of NDT by EC to design and simulate EC probes and the prototypes developed were tested in industrial environment, reaching a TRL ≈ 5. Another objective, of a more scientific and disruptive nature, was to test a new technique for the creation of EC in the materials to be inspect, named Magnetic Permeability Pattern Substrate (MPPS). This technique consists on the development of substrates/films with patterns of different magnetic permeabilities rather than the use of excitation bobbin coils or filaments of complex geometry. The experimental results demonstrated that the prototypes developed for the three industrial applications studied outperformed the state of the art, allowing the detection of target defects with a very good signal-to-noise ratio: in tubular geometries defects with depth of 0.5 mm and thickness of 0.2 mm in any scanning position; in the laser brazed weld beads pores with 0.13 mm diameter and internal artificial defects 1 mm from the weld surface; in composite materials defects under 1 mm at speeds up to 4 m/s and 3 mm lift-off. The numerical simulations assisted the probe design, allowing to describe and characterize electrical and magnetic phenomena. The new MPPS concept for the introduction of EC was validated numerically and experimentally

An architecture to predict anomalies in industrial processes

Dissertation presented as the partial requirement for obtaining a Master's degree in Data Science and Advanced Analytics, specialization in Data ScienceThe Internet of Things (IoT) and machine learning algorithms (ML) are enabling a revolutionary change in digitization in numerous areas, benefiting Industry 4.0 in particular. Predictive maintenance using machine learning models is being used to protect assets in industry. In this paper, an architecture for predicting anomalies in industrial processes was proposed in which SMEs can be guided in implementing an IIoT architecture for predictive maintenance (PdM). This research was conducted to understand what machine learning architectures and models are generally used by industry for PdM. An overview of the concepts of the Industrial Internet of Things (IIoT), machine learning (ML), and predictive maintenance (PdM) was provided, and through a systematic literature review, it was possible to understand their applications and which technologies enable their use. The survey revealed that PdM applications are increasingly common and that there are many studies on the development of new ML techniques. The survey conducted confirmed the usefulness of the artifact and showed the need for an architecture to guide the implementation of PdM. This research can be a contribution for SMEs, allowing them to become more efficient and reduce both production and maintenance costs in order to keep up with multinational companies