Sustainable short-term production planning optimization

This study proposes a framework for short-term production planning of a Portuguese company operating as a tier 2 supplier in the automotive sector. The framework is intended to support the decision-making process regarding a single progressive hydraulic press, which is used to manufacture cold-stamped parts for exhaust systems. The framework consists of two sequential levels: (1) a Mixed-Integer Linear Programming (MILP) model to determine the optimal production quantities per week while minimizing the total cost; (2) a dynamic production sequencing rule for scheduling operations on the hydraulic press. The two levels are combined and implemented in Excel, where the MILP model is solved using the Solver add-in, and the second level uses the optimal production quantities as inputs to determine the production sequence using a dynamic priority rule. To validate the framework, a proposed optimal plan was compared to a real plan executed by the company, and it was found that the framework could save up to 22.1% of the total cost observed in reality while still satisfying demand. To address uncertainties, the framework requires a rolling weekly planning horizon.This work has been supported by Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES (PIDDAC) to CeDRI (UIDB/05757/2020 and UIDP/05757/2020) and SusTEC (LA/P/0007/2021).info:eu-repo/semantics/publishedVersio

Data Aggregation and Packet Bundling of Uplink Small Packets for Monitoring Applications in LTE

In cellular massive Machine-Type Communications (MTC), a device can transmit directly to the base station (BS) or through an aggregator (intermediate node). While direct device-BS communication has recently been in the focus of 5G/3GPP research and standardization efforts, the use of aggregators remains a less explored topic. In this paper we analyze the deployment scenarios in which aggregators can perform cellular access on behalf of multiple MTC devices. We study the effect of packet bundling at the aggregator, which alleviates overhead and resource waste when sending small packets. The aggregators give rise to a tradeoff between access congestion and resource starvation and we show that packet bundling can minimize resource starvation, especially for smaller numbers of aggregators. Under the limitations of the considered model, we investigate the optimal settings of the network parameters, in terms of number of aggregators and packet-bundle size. Our results show that, in general, data aggregation can benefit the uplink massive MTC in LTE, by reducing the signalling overhead.Comment: to appear in IEEE Networ

The role of quenching time in the evolution of the mass-size relation of passive galaxies from the WISP survey

We analyze how passive galaxies at z $\sim$ 1.5 populate the mass-size plane as a function of their stellar age, to understand if the observed size growth with time can be explained with the appearance of larger quenched galaxies at lower redshift. We use a sample of 32 passive galaxies extracted from the Wide Field Camera 3 Infrared Spectroscopic Parallel (WISP) survey with spectroscopic redshift 1.3 $\lesssim$ z $\lesssim$ 2.05, specific star-formation rates lower than 0.01 Gyr$^{-1}$, and stellar masses above 4.5 $\times$ 10$^{10}$ M$_\odot$. All galaxies have spectrally determined stellar ages from fitting of their rest-frame optical spectra and photometry with stellar population models. When dividing our sample into young (age $\leq$ 2.1 Gyr) and old (age $>$ 2.1 Gyr) galaxies we do not find a significant trend in the distributions of the difference between the observed radius and the one predicted by the mass-size relation. This result indicates that the relation between the galaxy age and its distance from the mass-size relation, if it exists, is rather shallow, with a slope alpha $\gtrsim$ -0.6. At face value, this finding suggests that multiple dry and/or wet minor mergers, rather than the appearance of newly quenched galaxies, are mainly responsible for the observed time evolution of the mass-size relation in passive galaxies.Comment: Accepted for publication in ApJ Letters; 6 pages, 3 figures, 1 tabl

A pricing formula for delayed claims: appreciating the past to value the future

We consider the valuation of contingent claims with delayed dynamics in a Samuelson complete market model. We find a pricing formula that can be decomposed into terms reflecting the current market values of the past and the future, showing how the valuation of prospective cashflows cannot abstract away from the contribution of the past. As a practical application, we provide an explicit expression for the market value of human capital in a setting with wage rigidity. The formula we derive has successfully been used to explicitly solve the infinite dimensional stochastic control problems addressed in [7], [6] and [16]

Kinetic models for epidemic dynamics with social heterogeneity

We introduce a mathematical description of the impact of sociality in the spread of infectious diseases by integrating an epidemiological dynamics with a kinetic modeling of population-based contacts. The kinetic description leads to study the evolution over time of Boltzmann-type equations describing the number densities of social contacts of susceptible, infected and recovered individuals, whose proportions are driven by a classical SIR-type compartmental model in epidemiology. Explicit calculations show that the spread of the disease is closely related to moments of the contact distribution. Furthermore, the kinetic model allows to clarify how a selective control can be assumed to achieve a minimal lockdown strategy by only reducing individuals undergoing a very large number of daily contacts. We conduct numerical simulations which confirm the ability of the model to describe different phenomena characteristic of the rapid spread of an epidemic. Motivated by the COVID-19 pandemic, a last part is dedicated to fit numerical solutions of the proposed model with infection data coming from different European countries

Treating Diabetes and Hypertension in the Obese Patient

Obesity is an independent risk factor for coronary heart disease and it is associated with insulin resistance, which contributes to the development of dyslipidemia, hypertension, and type 2 diabetes. The coexistence of hypertension and diabetes increases the risk for macrovascular and microvascular complications, predisposing patients to congestive heart failure, coronary heart disease, cerebral and peripheral vascular diseases, nephropathy, and retinopathy. In obese diabetic patients, body weight reduction, as well as metiformin therapy, increase insulin sensitivity and enhance blood pressure and glicemic control. Antihypertensive treatment in diabetic patients decreases cardiovascular mortality and delays the decline of the glomerular function. Pharmacological treatment should consider the effects of the antihypertensive agents on insulin sensitivity and lipid profile. Diuretics and b-blockers are reported to reduce insulin sensitivity, whereas calcium channel blockers are metabolically neutral and ACE inhibitors increase insulin sensitivity and confer additional renal and vascular protection to diabetic patients. Angiotensin II antagonists has shown similar effects.A obesidade é um fator de risco independente para doença coronariana. A resistência à insulina associada à obesidade contribui para o desenvolvimento de dislipidemia, hipertensão arterial e diabetes tipo 2. A coexistência de hipertensão e diabetes aumenta o risco para complicações micro e macrovasculares, predispondo os indivíduos à insuficiência cardíaca congestiva, doença coronariana e cerebrovascular, insuficiência arterial periférica, nefropatia e retinopatia. Em pacientes diabéticos obesos a redução do peso, bem como o uso de metiformina, melhoram a sensibilidade à insulina, o controle da glicemia e da pressão arterial. O tratamento anti-hipertensivo em diabéticos reduz a mortalidade cardiovascular e retarda o declínio da função glomerular. Deve-se considerar os efeitos dos agentes anti-hipertensivos sobre a sensibilidade à insulina e o perfil lipídico. Diuréticos e b-bloqueadores podem reduzir a sensibilidade à insulina, enquanto bloqueadores de canais de cálcio são metabolicamente neutros e os iECA aumentam a sensibilidade à insulina, além de conferir proteção adicional cardiovascular e renal para diabéticos. O bloqueio da angiotensina II tem mostrado benefícios semelhantes.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUNIFESP, EPMSciEL

Determination of Flavonoids and Resveratrol in Wine by Turbulent-Flow Chromatography-LC-MS

Turbulent-flow chromatography (TFC) on-line coupled to liquid chromatography mass spectrometry (LC-MS) is used to determine flavonoids and resveratrol in different types of wines. A fully automated system was developed in which 10 mL of sample (diluted wine) was passed over a TFC column, after which the retained analytes were separated by reversed-phase LC and detected by negative ion mode atmospheric-pressure chemical ionization (APCI) MS. The method proved to be fast, non-laborious, robust and sensitive. The feasibility of the method was tested on several red, white and rose wines. Quantitation of resveratrol was possible using the standard addition procedure. Red wine showed the highest amount of resveratrol (4 mg