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Analysis of the Behavior of a Chemical tanker in Extreme Waves

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哈尔滨工程大学学报(英文版) 2024年第4期23卷 877-899页

作者： Shan Wang Marco Klein Soren Ehlers Günther Clauss C.Guedes Soares Centre for Marine technology and Ocean Engineering(CENtEC) Instituto Superior TécnicoUniversidade de LisboaAvenida Rovisco PaisLisboa 1049-001Portugal German Aerospace Center(DLR) Institute of Maritime Energy SystemsDüneberger Straße 108Geesthacht 21502Germany technische Universität Berlin Ocean Engineering DivisionSalzufer 17-19Berlin 10587Germany

the behavior of a chemical tanker(Ct)in extreme waves was discussed in detail,that is,in terms of rigid body heave and pitch motions,vertical bending moments(VBMs)amidships,green water,and slamming impacts through the analysis of the experimental data from model *** wave tests conducted for two wave steepness showed that the increase in wave steepness caused the increase in the asymmetry between hogging and sagging moments and the contribution of green water on deck to the decrease in vertical wave bending *** uncertainty analysis of statistical values in irregular wave tests with various seeds revealed slight experimental uncertainties on motions and VBMs and slightly higher errors in slamming pressure *** the increase in forward speed,experimental uncertainty on slamming pressures at the bow *** solutions of the nonlinear Schrödinger equation applied to generate tailored extreme waves of certain critical wavelengths showed a good performance in terms of ship response,and it was further verified for the Ct.

关键词： Extreme wave events Wave-structure interaction Draupner wave Breather solutions Model tests

Spin Number Coherent States and the Problem of two Coupled Oscillators

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Communications in theoretical Physics 2015年第7期64卷 34-38页

作者： D.Ojeda-Guillén R.D.Mota V.D.Granados Escuela superior de Fisica y Matemáticas Instituto Politécnico Nacional Ed. 9 Unidad Profesional Adolfo López Mateos Escuela superior de Ingenieria Mecánica y Eléctrica Unidad Culhuacán Instituto Politécnico Nacional

From the definition of the standard Perelomov coherent states we introduce the Perelomov number coherent states for any su(2) Lie algebra. With the displacement operator we apply a similarity transformation to the su(2)generators and construct a new set of operators which also close the su(2) Lie algebra, being the Perelomov number coherent states the new basis for its unitary irreducible representation. We apply our results to obtain the energy spectrum, the eigenstates and the partition function of two coupled oscillators. We show that the eigenstates of two coupled oscillators are the SU(2) Perelomov number coherent states of the two-dimensional harmonic oscillator with an appropriate choice of the coherent state parameters.

关键词： coherent states Lie algebras coupled oscillators

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Microstructure and properties of laser direct deposited CuNi17Al3Fe1.5Cr alloy

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International Journal of Minerals,Metallurgy and Materials 2011年第3期18卷 325-329页

作者： Yong-zhong Zhang Can Huang Rui Vilar Center for Composites General Research Institute for Non-ferrous Metals Beijing 100088 China Department of Materials Engineering and Institute of Materials and Surfaces Science and Engineering Instituto Superior Técnico 1049-001 Lisbon Portugal

thin walls of a copper-base alloy with the nominal composition CuNi17Al3Fe1.5Cr were successfully prepared by laser direct deposition additive manufacturing. the microstructure, as revealed by optical and scanning electron microscopy, indicated that the deposited material was fully dense and with a dendritic microstructure. the dendrites are parallel to the build-up direction, which is also the heat con-duction direction during deposition. X-ray diffraction analysis results show that the deposited material is composed of a single phase and a copper-based solid solution. Some precipitate particles of metal silicides were observed in the interdendritic region by scanning electron mi-croscopy. the ultimate tensile strength along the laser scanning direction reaches 735 MPa. the hardness is about Hv0.1 300.

关键词： copper alloys laser deposition microstructure mechanical properties

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NDRank: optimised parallel search for weather analogues

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Big Earth Data 2023年第2期7卷 276-297页

作者： David Martins Miguel Ferreira João Nuno Silva instituto superior técnico Universidade de LisboaLisboaPortugal Caravela Energy Partners DarienConnecticutUSA Distributed Parallel and Secure Systems GroupINESC-ID LisboaLisboaPortugal

Global meteorology data are now widely used in various areas, but one of its applications, weather analogues, still require exhaustive searches on the whole historical data. We present two optimisations for the state-of-the-art weather analogue search algorithms: a parallelization and a heuristic search. the heuristic search (NDRank) limits of the final number of results and does initial searches on a lower resolution dataset to find candidates that, in the second phase, are locally validated. these optimisations were deployed in the Cloud and evaluated with ERA5 data from ECMWF. the proposed parallelization attained speedups close to optimal, and NDRank attains speedups higher than 4. NDRank can be applied to any parallel search, adding similar speedups. A substantial number of executions returned a set of analogues similar to the existing exhaustive search and most of the remaining results presented a numerical value difference lower than 0.1%. the results demonstrate that it is now possible to search for weather analogues in a faster way (even compared with parallel searches) with results with little to no error. Furthermore, NDRank can be applied to existing exhaustive searches, providing faster results with small reduction of the precision of the results.

关键词： Multidimensional arrays weather analogues search parallel computing algorithm optimisation

Liver disorders in COVID-19,nutritional approaches and the use of phytochemicals

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World Journal of Gastroenterology 2021年第34期27卷 5630-5665页

作者： Nancy Vargas-Mendoza Jazmín García-Machorro Marcelo Angeles-Valencia Marlet Martínez-Archundia Eduardo Osiris Madrigal-Santillán Ángel Morales-González Liliana Anguiano-Robledo JoséA Morales-González Laboratorio de Medicina de Conservacion Instituto Politécnico NacionalMéxico 11340Mexico Laboratorio de Diseño y Desarrollo de Nuevos Fármacos e Innovación Biotécnológica Instituto Politécnico NacionalMéxico 11340Mexico superior de Medicina Instituto Politécnico NacionalMéxico 11340Mexico Escuela superior de Cómputo Instituto Politécnico NacionalMéxico 07738Mexico Laboratorio de Farmacología Molecular Instituto Politécnico NacionalMéxico 11340Mexico Laboratorio Medicina de Conservación Escuela Superior de MedicinaInstituto Politécnico NacionalMéxico 11340Mexico

Coronavirus disease 2019(COVID-19),which is caused by severe acute respiratory syndrome-coronavirus-2(SARS-CoV-2),has affected millions of people *** was declared a pandemic by the World Health Organization in March *** hyperinflammatory response to the entry of SARS-CoV-2 into the host through angiotensin-converting enzyme 2 is the result of a“cytokine storm”and the high oxidative stress responsible for the associated *** only respiratory symptoms are reported,but gastrointestinal symptoms(diarrhea,vomiting,and nausea)and liver abnormalities(high levels of aspartate aminotransferase,alanine aminotransferase transaminases,and bilirubin)are observed in at least 30%of *** food intake and a delay in medical services may lead to malnutrition,which increases mortality and poor *** review provides some strategies to identify malnutrition and establishes nutritional approaches for the management of COVID-19 and liver injury,taking energy and nutrient requirements and their impact on the immune response into *** roles of certain phytochemicals in the prevention of the disease or as promising target drugs in the treatment of this disease are also considered.

关键词： COVID-19 Infection Liver Nutrition therapy Phytochemicals

Optimization of a photovoltaic-battery system using deep reinforcement learning and load forecasting

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Energy and AI 2024年第2期16卷 168-183页

作者： António Corte Real G.Pontes Luz J.M.C.Sousa M.C.Brito S.M.Vieira IDMEC Instituto Superior TécnicoUniversidade de LisboaLisboa1049-001Portugal instituto Dom Luiz Faculdade de CiênciasUniversidade de LisboaCampo Grande1749-016LisboaPortugal

Home Energy Management Systems(HEMS)are increasingly relevant for demand-side management at the residential level by collecting data(energy,weather,electricity prices)and controlling home appliances or storage *** control can be performed with classical models that find optimal solutions,with high real-time computational cost,or data-driven approaches,like Reinforcement Learning,that find good and flexible solutions,but depend on the availability of load and generation data and demand high computational resources for *** this work,a novel HEMS is proposed for the optimization of an electric battery operation in a real,online and data-driven environment that integrates state-of-the-art load forecasting combining CNN and LStM neural networks to increase the robustness of *** Reinforcement Learning agents are trained with different algorithms(Double DQN,Dueling DQN,Rainbow and Proximal Policy Optimization)in order to minimize the cost of electricity purchase and to maximize photovoltaic self-consumption for a PV-Battery residential *** show that the best Reinforcement Learning agent achieves a 35%reduction in total cost when compared with an optimization-based agent.

关键词： Energy management system Deep reinforcement learning Demand-side management Load forecasting Deep learning Energy storage systems

On the Darboux Integrability of the Hindmarsh–Rose Burster

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Acta Mathematica Sinica,English Series 2018年第6期34卷 947-958页

作者： Jaume LLIBRE Claudia VALLS Departament de Matematiques Universitat Autonoma de Barcelona 08193 BeUaterra Barcelona Catalonia Spain Departamento de Matematica Instituto Superior TecnicoUniversidade Tecnica de Lisboa Av. Rovisco Pals 1049-001 Lisboa Portugal

We study the Hindmarsh-Rose burster which can be described by the differential system x^·=y-x^3＋bx^2＋I-z,y^·=1-5x^2-y,z^·=μ（s（x-x0）-z）where b, I, μ, s, x0 are parameters. We characterize all its invariant algebraic surfaces and all its exponential factors for all values of the parameters. We also characterize its Darboux integrability in function of the parameters. these characterizations allow to study the global dynamics of the system when such invariant algebraic surfaces exist.

关键词： Polynomial integrability rational integrability Darboux polynomials Darboux first integrals invariant algebraic surfaces exponential factors Hindmarsh Rose burster

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Gain and ultrafast optical switching in PMMA optical fibers and films doped with luminescent conjugated polymers and oligomers

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Frontiers of Optoelectronics 2010年第1期3卷 45-53页

作者： Ana CHARAS Ana L.MENDON?A Jenny CLARK Juan CABANILLAS-GONZALEZ Luca BAZZANA Alessandro NOCIVELLI Guglielmo LANZANI Jorge MORGADO instituto de telecomunica??es Department of Chemical and Biological Engineering Instituto Superior Técnico Department of Physics Politecnico di Milano Luceat S.p.A.

Conjugated luminescent polymers and oligomers, exhibiting stimulated emission(SE), are dispersed in polymethylmethacrylate(PMMA), films and optical fibers,either by blending or upon copolymerisation. With this PMMA doping, we aim to achieve gain and ultrafast optical switching. the modification of the dopant's chemical structure allows the tuning of the SE spectral region. Furthermore, we aim to achieve dopant chain isolation while maximising their concentration. In this paper, we present an overview of the research done in this area in the context of the European Union(EU)-funded research project “plastic optical fibers with embedded active polymers for data communications——POLYCOM”.

关键词： plastic optical fibers optical gain and switching conjugated luminescent polymers dopants

Domain adversarial training for classification of cracking in images of concrete surfaces

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AI in Civil Engineering 2022年第1期1卷 119-132页

作者： Bruno Oliveira Santos Jónatas Valença João P.Costeira Eduardo Julio CERIS Instituto Superior TécnicoUniversity of LisbonLisbonPortugal ISR Instituto Superior TécnicoUniversity of LisbonLisbonPortugal

the development of automatic methods to recognize cracks in surfaces of concrete has been under focus in recent years,firstly through computer vision methods and more recently focusing on convolutional neural networks that are delivering promising *** are still persisting in crack recognition,namely due to the confusion added by the myriad of elements commonly found on concrete *** robustness of these methods would deal with these elements if access to correspondingly heterogeneous datasets was *** so,this would be a cumbersome methodology,since training would be needed for each particular case and models would be case ***,efforts from the scientific community are focusing on generalizing neural network models to achieve high per-formance in images from different domains,slightly different from those in which they were effectively *** generalization of networks can be achieved by domain adaptation techniques at the training *** adapta-tion enables finding a feature space in which features from both domains are invariant,and thus,classes become *** work presented here proposes the DA-Crack method,which is a domain adversarial training method,to generalize a neural network for recognizing cracks in images of concrete *** domain adversarial method uses a convolutional extractor followed by a classifier and a discriminator,and relies on two datasets:a source labeled dataset and a target unlabeled small *** classifier is responsible for the classification of images randomly chosen,while the discriminator is dedicated to uncovering to which dataset each image *** from the discriminator reverses the gradient used to update the *** enables fighting the convergence promoted by the updating backpropagated from the classifier,and thus generalizing the extractor enabling it for crack recognition of images from both source and target *** show that

关键词： DA-Crack method Domain-adaptation Adversarial training network Crack detection Concrete surfaces Computer vision