Ex-ante methods to assess the impact of social insurance policies on labor supply with an application to Brazil

This paper solves and estimates a stochastic model of optimal inter-temporal behavior to assess how changes in the design of the unemployment benefits and pension systems in Brazil could affect savings rates, the share of time that individuals spend outside of the formal sector, and retirement decisions. Dynamics depend on five main parameters: preferences regarding consumption and leisure, preferences regarding formal versus informal work, attitudes towards risks, the rate of time preference, and the distribution of an exogenous shock that affects movements in and out of the social insurance system (given individual decisions). The yearly household survey is used to create a pseudo panel by age-cohorts and estimate the joint distribution of model parameters based on a generalized version of the Gibbs sampler. The model does a good job in replicating the distribution of the members of a given cohort across states (in or out of the social insurance / active or retired). Because the parameters are related to individual preferences or exogenous shocks, the joint distribution is unlikely to change when the social insurance system changes. Thus, the model is used to explore how alternative policy interventions could affect behaviors and through this channel, benefit levels and fiscal costs. The results from various simulations provide three main insights: (i) the Brazilian social insurance system today might generate unnecessary distortions (lower savings rates and less formal employment) that increase the costs of the system and can induce regressive redistribution; (ii) there are important interactions between the unemployment benefits and pension systems, which calls for joint policy analysis when considering reforms; and (iii) current distortions could be reduced by creating an actuarial link between contributions and benefits and then combining matching contributions and anti-poverty targeted transfers to cover individuals with limited or no savings capacity.Pensions&Retirement Systems,Emerging Markets,Labor Policies,Labor Markets,Debt Markets

An Enhanced Reservation-Based MAC Protocol for IEEE 802.15.4 Networks

The IEEE 802.15.4 Medium Access Control (MAC) protocol is an enabling standard for wireless sensor networks. In order to support applications requiring dedicated bandwidth or bounded delay, it provides a reservation-based scheme named Guaranteed Time Slot (GTS). However, the GTS scheme presents some drawbacks, such as inefficient bandwidth utilization and support to a maximum of only seven devices. This paper presents eLPRT (enhanced Low Power Real Time), a new reservation-based MAC protocol that introduces several performance enhancing features in comparison to the GTS scheme. This MAC protocol builds on top of LPRT (Low Power Real Time) and includes various mechanisms designed to increase data transmission reliability against channel errors, improve bandwidth utilization and increase the number of supported devices. A motion capture system based on inertial and magnetic sensors has been used to validate the protocol. The effectiveness of the performance enhancements introduced by each of the new features is demonstrated through the provision of both simulation and experimental results

Evolution of the far-infrared luminosity functions in the Spitzer Wide-area Infrared Extragalactic Legacy Survey

We present new observational determination of the evolution of the rest-frame 70 and 160 micron and total infrared (TIR) galaxy luminosity functions (LFs) using 70 micron data from the Spitzer Wide-area Infrared Extragalactic Legacy Survey (SWIRE). The LFs were constructed for sources with spectroscopic redshifts only in the XMM-LSS and Lockman Hole fields from the SWIRE photometric redshift catalogue. The 70 micron and TIR LFs were constructed in the redshift range 0<z<1.2 and the 160 micron LF was constructed in the redshift range 0<z<0.5 using a parametric Bayesian and the vmax methods. We assume in our models, that the faint-end power-law index of the LF does not evolve with redshifts. We find the the double power-law model is a better representation of the IR LF than the more commonly used power-law and Gaussian model. We model the evolution of the FIR LFs as a function of redshift where where the characteristic luminosity, $L^\ast$ evolve as \propto(1+z)^{\alpha_\textsc{l}}. The rest-frame 70 micron LF shows a strong luminosity evolution out to z=1.2 with alpha_l=3.41^{+0.18}_{-0.25}. The rest-frame 160 micron LF also showed rapid luminosity evolution with alpha_l=5.53^{+0.28}_{-0.23} out to z=0.5. The rate of evolution in luminosity is consistent with values estimated from previous studies using data from IRAS, ISO and Spitzer. The TIR LF evolves in luminosity with alpha_l=3.82^{+0.28}_{-0.16} which is in agreement with previous results from Spitzer 24 micron which find strong luminosity evolution. By integrating the LF we calculated the co-moving IR luminosity density out to z=1.2, which confirm the rapid evolution in number density of LIRGs and ULIRGs which contribute ~68^{+10}_{-07} % to the co-moving star formation rate density at z=1.2. Our results based on 70 micron data confirms that the bulk of the star formation at z=1 takes place in dust obscured objects.Comment: 17 pages, 14 figure

Predicting people’s concentration and movements in a smart city

With the rapid growth of urbanization and the proliferation of mobile phone usage, smart city initiatives have gained momentum in leveraging data-driven insights to enhance urban planning and resource allocation. This paper proposes a novel approach for predicting people’s concentration and movements within a smart city environment using mobile phone data provided by telecommunication operators. By harnessing the vast amount of anonymized and aggregated mobile phone data, we present a predictive framework that offers valuable insights into urban dynamics. The methodology involves collecting and processing location-based data obtained from telecommunication operators. Using machine learning techniques, including clustering and spatiotemporal analysis, we developed models to identify patterns in people’s movements and concentration across various city regions. Our proposed approach considers factors such as time of day, day of the week, and special events to capture the intricate dynamics of urban activities. The predictive models presented in this paper demonstrate the ability to predict areas of high concentration of people, such as commercial districts during peak hours, as well as the people flow during the time. These insights have significant implications for urban planning, traffic management, and resource allocation. Our approach respects user privacy by working with aggregated and anonymized data, ensuring compliance with privacy regulations and ethical considerations. The proposed models were evaluated using real-world mobile phone data collected from a smart city environment in Lisbon, Portugal. The experimental results demonstrate the accuracy and effectiveness of our approach in predicting people’s movements and concentration. This paper contributes to the growing field of smart city research by providing a data-driven solution for enhancing urban planning and resource allocation strategies. As cities continue to evolve, leveraging mobile phone data from telecommunication operators can lead to more efficient and sustainable urban environmentsThis work was supported by the Fundação para a Ciência e Tecnologia under Grant [UIDB/00315/2020]; and by the project “BLOCKCHAIN.PT (RE-C05-i01.01—Agendas/Alianças Mobilizadoras para a Reindustrialização, Plano de Recuperação e Resiliência de Portugal” in its component 5—Capitalization and Business Innovation and with the Regulation of the Incentive System “Agendas for Business Innovation”, approved by Ordinance No. 43-A/2022 of 19 January 2022)

Development of a proposed single-phase series active power filter without external power sources

The quality of electric power is receiving more and more attention from part of consumers, Distribution System Operators (DSO), Transmission System Operators (TSO) and other competent entities related to the electrical power system. Once the electrical Power Quality (PQ) problems have direct implications for business productivity, causing high economic losses, it is mandatory to develop solutions that mitigate these problems. Active Power Filters (APFs) are power electronic equipment capable of compensating PQ problems that have the ability to dynamically adjust their modes of operation in response to changes in load or in the power system. Among these solutions, the Series Active Power Filter (SeAPF) is specially conceived to deal with problems related to the power system voltage amplitude and waveform. Despite the ability to compensate voltage sags, voltage swells, voltage harmonics, and voltage imbalances in three-phase systems, the SeAPF has not achieved much success neither has not been widely adopted. The lack of interest in this equipment can be largely justified by its high cost and also because of some limitations presented by the SeAPF conventional topology. In this paper is presented a novel topology, as well as the control algorithms of a single-phase SeAPF that is connected directly to the power grid without the use of coupling transformers and that does not require the use of external power sources. The topology and control algorithms of the SeAPF proposed in this paper were firstly evaluated by means of simulation results obtained with PSIM software and, once validated, a laboratory prototype was developed, being presented experimental results that support the correct operation of the proposed system.This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2019. This work is financed by the ERDF – COMPETE 2020 Programme, and by FCT within project SAICTPAC/0004/2015-POCI-01-0145-FEDER-016434 and by FCT within project PTDC/EEI-EEE/28813/2017. Mr. Luis A. M. Barros is supported by the doctoral scholarship PD/BD/143006/2018 granted by the Portuguese FCT agency

A Retrospective Study Characterizing Myocardial Strain Patterns in Patients with Mitral Annular Disjunction with and without Mitral Valve Prolapse

Background: Mitral annular disjunction (MAD) is an atrial displacement of the mitral valve hinge point. MAD may occur with or without mitral valve prolapse (MVP) and has been linked to ventricular arrhythmias (VA) and sudden cardiac death (SCD). Although cardiac magnetic resonance imaging (cMRI) is the gold standard for MAD detection, it is not practical for screening. We used 2D transthoracic echocardiography (TTE) with speckle tracking echocardiography (STE) to characterize segmental and global longitudinal myocardial strain (SLMS, GLMS) patterns in patients with MAD, +/-MVP. Methods: 43 subjects were identified by searching “MAD” in our institution’s database. GLMS and SLMS patterns were analyzed by STE, and hospital charts were reviewed to record comorbidities. Results: 43 MAD patients (36 +MVP and 7 -MVP) were studied using 2D TTE (average MAD distance 9.6 mm, range 3-22mm). 17 (40%) patients had prior VA (average MAD distance 11.6mm, range 6.6-22mm). Average GLMS was -18.2%; attenuated MS was noted in basal inferior, inferoseptal, and anteroseptal segments (-15.2%, -12.5%, and –13.8%, respectively). Conclusion: It is postulated that MAD causes myocardial fibrosis, leading to arrhythmia. Though MAD can be identified on cMRI, TTE is a better screening test, and STE with MS mapping may offer a novel way of additional characterization. Clinical Implications: We used TTE with STE for MS mapping to profile GLMS and SLMS in patients with MAD, +/-MVP. Our results show that deranged basal LMS may reflect MAD severity. Future research should optimize screening practices with STE to improve outcomes for patients with MAD

Study on the technological and economic viability of introducing energy storage systems with solar photovoltaic panels

Solar photovoltaic represent one of the most promising technologies for generating electrical energy from renewable sources. In fact, as a result of the technological advances in the field of microelectronics and power electronics, photovoltaic systems have reached historic lows in terms of costs, surpassing the other types of renewable energy sources. The potential of the solar photovoltaic systems is enormous, being capable of meeting the energy needs of today, without compromising future needs, and allowing a sustainable development. With this in mind, several incentives and, consequently, legislations have been implemented around the world. In the Portuguese case, depending on the type of contract, for photovoltaic solar installations with value of power up to 1500 Wp the production surplus is injected into the power grid without any financial compensation. Considering the high investment, particularly regarding the photovoltaic panels, the support structure and the power electronics converters, it could be interesting to implement a system capable of storing the surplus energy for later use by the owner of the photovoltaic installation. This paper presents a study on the viability of energy storage systems in photovoltaic installations up to 1500 Wp. For this study, different consumer profiles, types of installations and geographic locations were considered, in order to perceive the technological and economic viability of this solution.This work has been supported by FCT -Fundancao para a Ciencia e Tecnologia within the Project Scope: UID/CEC/00319/2019. This work is financed by the ERDF COMPETE 2020 Programme, and FCT within project SAICTPAC/0004/2015-POCI-01-0145-FEDER-016434 and FCT within project PTDC/EEI-EEE/28813/2017. Mr. Luis A. M. Barros is supported by the doctoral scholarship PD/BD/143006/2018 granted by the Portuguese FCT agency

Use of ultraviolet C (UVC) radiation to inactivate infectious hematopoietic necrosis virus (IHNV) and viral haemorrhagic septicaemia virus (VHSV) in fish processing plant effluent

We determined the stability of infectious hematopoietic necrosis virus (IHNV) and viral hemorrhagic septicemia virus (VHSV) suspended in either fish processing plant effluent blood water (EBW) or culture media and examined the effectiveness of UVC radiation to inactivate IHNV and VHSV suspended in both solutions. Without exposure to UVC, IHNV and VHSV were maintained in 4&deg;C blood water for up to 48 hours without significant reduction in virus titer. However when exposed to UVC radiation using a low pressure mercury vapour lamp collimated beam, IHNV and VHSV were inactivated, and the efficacy of UVC radiation was dependent upon the solution and virus type being treated. A 3-log reduction for VHSV and IHNV in culture media was achieved at 3.28 and 3.84 mJ cm-2, respectively. The UV dose needed for a 3-log reduction of VHSV in EBW was 3.82 mJ cm-2. However, exposure of IHNV in EBW to the maximum UVC dose tested (4.0 mJ cm-2) only led to a 2.26-log-reduction. Factors such as particle size, and possible association of viruses with suspended EBW particulate, were not investigated in this study, but may have contributed to the difference in UVC effectiveness. Future work should emphasize improved filtration methods prior to UV treatment of processing plant EBW at an industrial scale.<br /

Opportunities and challenges of power electronics systems in future railway electrification

With the continuous expansion of the railway power systems, the integration of high speed locomotives and the need to increase the overhead catenary line power capacity, the main shortcomings of the conventional railway feeding system are becoming more evident. In order to overcome these drawbacks and to contribute to the technological evolution with innovative and electrically more efficient systems, several solutions have been proposed and implemented. In this context, this paper briefly presents a study of different railway power systems, highlighting emerging concepts, such as regenerative braking, energy storage systems, the inclusion of renewable energy sources, bidirectional power flow and wireless power transfer. Some of these concepts can be implemented in short to medium term, or in the long term. Following these concepts, an overview of the power electronics challenges for the implementation of these emerging concepts is presented and discussed.This work has been supported by FCT –Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020. This work has been supported by the FCT Project QUALITY4POWER PTDC/EEI-EEE/28813/2017. Mr. Luis A. M. Barros is supported by the doctoral scholarship PD/BD/143006/2018 granted by the Portuguese FCT foundation. Mr. Mohamed Tanta was supported by FCT PhD grant with a reference PD/BD/127815/2016

Evaluation of static synchronous compensator and rail power conditioner in electrified railway systems using V/V and Scott power transformers

In this paper a comprehensive review of electrified railway systems is carried out, identifying the electric power quality deterioration which may appear due to nonlinear dynamic traction loads. Following this topic, a computational simulation of Static Synchronous Compensator (STATCOM) and Rail Power Conditioner (RPC) are presented, making a comprehensive analysis of each of these solutions regarding the power quality improvement in electrified railway systems. Four case studies are presented: (i) STATCOM evaluation when a traction power system is fed by a V/V power transformer; (ii)STATCOM evaluation when a traction power system is fed by a Scott power transformer; (iii) RPC evaluation when atraction power system is fed by a V/V power transformer; (iv) RPC evaluation when a traction power system is fed by aScott power transformer.This work has been supported by FCT – Fundação para a Ciência e Tecnologia with-in the Project Scope: UIDB/00319/2020. This work has been supported by the FCT Project QUALITY4POWER PTDC/EEI-EEE/28813/2017, and by the FCT Project DAIPESEV PTDC/EEI-EEE/30382/2017. Mr. Luis A. M. Barros is supported by the doctoral scholarship PD/BD/143006/2018 granted by the Portuguese FCT foundation. Mr. Mohamed Tanta was supported by FCT PhD grant with a reference PD/BD/127815/2016