Uma estrutura alternativa para a parametrização no controle robustoℋ∞ em tempo discreto

Nestatesededoutorado,apresenta-seumaestruturaalternativaparaaparametrizaçãode todos os controladores ℋ∞ para plantas descritas por uma fatoração coprima à esquerda qualquercomumametodologiageneralizadaparaocasoemtempodiscreto.Mostra-seque apartirdométodogenéricoparaasíntesedoscontroladoresℋ∞ admissíveis,ocontrolador central não estritamente próprio e o controlador estritamente próprio podem ser obtidos. Demonstra-se também que, a partir da fatoração coprima à esquerda normalizada, sob a perspectivadoframework propostonestetrabalho,épossível(i)obtertantoocontrolador centralemtempodiscretocomoocontroladorestritamenteprópriobaseadonasoluçãode otimização de duas equações algébricas de Riccati; (ii) encontrar o valor de um limitante derobustez(γmin)queserelacionadiretamentecomarobustezdoscontroladoresdeforma a apresentar que o controlador não estritamente próprio se mostra mais robusto que o controlador estritamente próprio. A metodologia de estabilização robusta ℋ∞ de plantas representadas por uma descrição em fatores coprimos tem recebido particular interesse pela simplicidade em seu uso e pela natureza geral como representa a incerteza nesse contexto. É uma metodologia capaz de incorporar objetivos de desempenho e robustez às incertezas na abordagem de projeto. Para investigar a aplicabilidade da tese proposta, a eficácia do framework desenvolvido e, consequentemente, do controlador em tempo discreto projetado, foram realizadas simulações e experimentos práticos na malha de controle de posição de uma esfera metálica de um modelo didático do levitador magnético fabricado pela empresa QUANSER

Uma Estratégia de Controle Multi-Modelo LQG/LTR Aplicada a um Sistema Não Linear de Levitação Magnética.

Este trabalho apresenta o desenvolvimento de uma nova estratégia de controle multi-modelo para aplicações em plantas não lineares. Realiza-se a união da metodologia clássica, com o desenvolvimento de controladores LQG/LTR em tempo discreto, junto à metodologia inteligente, através da lógica Fuzzy, de forma a obter como resultado um controlador híbrido que consiga driblar o problema da não linearidade existente em sistemas dinâmicos. Neste contexto, este trabalho apresenta uma estratégia de expandir a planta de processo por integradores backward Euler e, a partir da dinâmica da planta em malha aberta expandida, desenvolver e ajustar controladores multi-modelos LQG/LTR em tempo discreto e realizar a união destes via lógica Fuzzy para obter um controlador não linear global que atue na planta não linear de um sistema de levitação magnética. O objetivo do controlador não linear global proposto é ser capaz de rejeitar distúrbios, bem como manter o rastreamento do sistema para diferentes pontos de operação, usando a solução de controle multi-modelo LQG/LTR em tempo discreto unido a lógica Fuzzy. Para validação e comprovação da nova parametrização desenvolvida, foram realizadas simulações e ensaios práticos em um aparelho de levitação magnética da empresa canadense Quanser

Methodology for the management of discrete event simulation projects based on PMBOK ®: Action research in a high-tech company

© 2018 IEEE Discrete Event Simulation (DES) is a powerful tool for decision making. It has been widely used in different application fields. There are many works investigating the simulation modeling process, but little is found in the literature that considers how to manage a DES project. In this respect, this paper has the objective of proposing a specific methodology for the management of DES projects based on PMBOK. This was considered to be the methodology that most fits with the requirements of DES. In order to test the approach, PMBOK was applied in a real simulation project. The methodology was then evaluated by the simulation analysts who provided their feedback on the study

Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Measurement of the Splitting Function in &ITpp &ITand Pb-Pb Collisions at root&ITsNN&IT=5.02 TeV

Data from heavy ion collisions suggest that the evolution of a parton shower is modified by interactions with the color charges in the dense partonic medium created in these collisions, but it is not known where in the shower evolution the modifications occur. The momentum ratio of the two leading partons, resolved as subjets, provides information about the parton shower evolution. This substructure observable, known as the splitting function, reflects the process of a parton splitting into two other partons and has been measured for jets with transverse momentum between 140 and 500 GeV, in pp and PbPb collisions at a center-of-mass energy of 5.02 TeV per nucleon pair. In central PbPb collisions, the splitting function indicates a more unbalanced momentum ratio, compared to peripheral PbPb and pp collisions.. The measurements are compared to various predictions from event generators and analytical calculations.Peer reviewe

Measurement of nuclear modification factors of gamma(1S)), gamma(2S), and gamma(3S) mesons in PbPb collisions at root s(NN)=5.02 TeV

The cross sections for ϒ(1S), ϒ(2S), and ϒ(3S) production in lead-lead (PbPb) and proton-proton (pp) collisions at √sNN = 5.02 TeV have been measured using the CMS detector at the LHC. The nuclear modification factors, RAA, derived from the PbPb-to-pp ratio of yields for each state, are studied as functions of meson rapidity and transverse momentum, as well as PbPb collision centrality. The yields of all three states are found to be significantly suppressed, and compatible with a sequential ordering of the suppression, RAA(ϒ(1S)) > RAA(ϒ(2S)) > RAA(ϒ(3S)). The suppression of ϒ(1S) is larger than that seen at √sNN = 2.76 TeV, although the two are compatible within uncertainties. The upper limit on the RAA of ϒ(3S) integrated over pT, rapidity and centrality is 0.096 at 95% confidence level, which is the strongest suppression observed for a quarkonium state in heavy ion collisions to date. © 2019 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP3.Peer reviewe

Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe

MUSiC : a model-unspecific search for new physics in proton-proton collisions at root s=13TeV

Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1), are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.Peer reviewe

Measurement of prompt open-charm production cross sections in proton-proton collisions at root s=13 TeV

The production cross sections for prompt open-charm mesons in proton-proton collisions at a center-of-mass energy of 13TeV are reported. The measurement is performed using a data sample collected by the CMS experiment corresponding to an integrated luminosity of 29 nb(-1). The differential production cross sections of the D*(+/-), D-+/-, and D-0 ((D) over bar (0)) mesons are presented in ranges of transverse momentum and pseudorapidity 4 < p(T) < 100 GeV and vertical bar eta vertical bar < 2.1, respectively. The results are compared to several theoretical calculations and to previous measurements.Peer reviewe