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Decoupled Photovoltaic Power Ramp-rate Calculation Method for Perturb and Observe Algorithms

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Journal of Modern Power Systems and Clean Energy 2022年第4期10卷 932-940页

作者： Jose Miguel riquelme-Dominguez francisco M.Gonzalez-Longatt Sergio Martinez Electrical Engineering Department Escuela Tecnica Superior de Ingenieros IndustrialesUniversidad Politecnica de Madrid28006 MadridSpain Department of Electrical Engineering Information Technology and CyberneticsUniversity of South-Eastern Norway3918 PorsgrunnNorway

As photovoltaic energy increasingly penetrates in power systems,transmission system operators have started to request its participation in providing ancillary *** of the demanded services is the power ramp-rate control(PRRC),which attempts to limit the power ramps produced by intermittent irradiance *** order to achieve the desired objective,solutions based on storage systems or modifying the maximum power point tracking(MPPT)in perturb and observe(P&O)algorithms are commonly *** starting point in PRRC is the determination of the instantaneous power ramprate,and different methods have been proposed in the literature for its ***,the accuracy and computational speed of existing procedures can be improved,which may be critical in situations with rapid irradiance *** this paper,a decoupled photovoltaic power ramp-rate calculation method is presented,in which the effect of variable irradiance and the P&O algorithm are computed *** proposed method has been theoretically demonstrated and tested through simulation and experimental *** results show that it can improve the previous methods in terms of accuracy and computation *** validation with hardware-inthe-loop demonstrates the suitability of the proposed method for real-time applications,even in presence of noisy measurements.

关键词： Hardware-in-the-loop maximum power point tracking perturb and observe photovoltaic power ramp-rate control ramp-rate calculation method

Extremal Coalitions for Influence Games Through Swarm Intelligence-Based Methods

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Computers, Materials & Continua 2022年第3期70卷 6305-6321页

作者： Fabián riquelme Rodrigo Olivares francisco Munoz Xavier Molinero Maria Serna Escuela de Ingeniería Informática Universidad de ValparaísoValparaísoChile Computer Science Department Universitat Politècnica de CatalunyaBarcelonaSpain Mathematics Department Universitat Politècnica de CatalunyaTerrassaSpain

An influence game is a simple game represented over an influence graph(i.e.,a labeled,weighted graph)on which the influence spread phenomenon is *** games allow applying different properties and parameters coming from cooperative game theory to the contexts of social network analysis,decision-systems,voting systems,and collective *** exact calculation of several of these properties and parameters is computationally hard,even for a small number of *** examples of these parameters are the length and the width of a *** length of a game is the size of its smaller winning coalition,while the width of a game is the size of its larger losing *** parameters are relevant to know the levels of difficulty in reaching agreements in collective decision-making *** the above,new bio-inspired metaheuristic algorithms have recently been developed to solve the NP-hard influence maximization problem in an efficient and approximate way,being able to find small winning coalitions that maximize the influence spread within an influence *** this article,we apply some variations of this solution to find extreme winning and losing coalitions,and thus efficient approximate solutions for the length and the width of influence *** a case study,we consider two real social networks,one formed by the 58 members of the European Union Council under nice voting rules,and the other formed by the 705 members of the European Parliament,connected by political *** are promising and show that it is feasible to generate approximate solutions for the length and width parameters of influence games,in reduced solving time.

关键词： Influence game influence spread collective behavior swarm intelligence bio-inspired computing

High prevalence of hepatic steatosis and vascular thrombosis in COVID-19:A systematic review and meta-analysis of autopsy data

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World Journal of Gastroenterology 2020年第48期26卷 7693-7706页

作者： Luis Antonio Díaz francisco Idalsoaga Macarena Cannistra Roberto Candia Daniel Cabrera francisco Barrera Alejandro Soza Rondell Graham Arnoldo riquelme Marco Arrese Michael D Leise Juan Pablo Arab Department of Gastroenterology Escuela de MedicinaPontificia Universidad Católica de ChileSantiago 8320000Chile Department of Internal Medicine Pontificia Universidad Católica de ChileSantiago 8320000Chile School of Medicine Pontificia Universidad Católica de ChileSantiago 8320000Chile Facultad de Ciencias Médicas Universidad Bernardo O'HigginsSantiago 8320000Chile Department of Laboratory Medicine and Pathology Mayo Clinic RochesterMinnesotaMN 55902United States Católica de Chile Santiago 8320000Chile Division of Gastroenterology and Hepatology Mayo Clinic RochesterMinnesotaMN 55905United States

BACKGROUND Coronavirus disease 2019(COVID-19)disease can frequently affect the *** on hepatic histopathological findings in COVID-19 is *** To characterize hepatic pathological findings in patients with *** We conducted a systematic review with meta-analysis registered on PROSPERO(CRD42020192813),following PRISMA *** trials were those including patients of any age and COVID-19 diagnosis based on a molecular *** reports from deceased COVID-19 patients undergoing autopsy or liver biopsy were *** including less than ten patients were *** were pooled using random-effects models.Q statistic and I2 were used to assess heterogeneity and levels of evidence,*** We identified 18 studies from 7 countries;all were case reports and case series from *** the patients were over 15 years old,and 67.2%were *** performed a meta-analysis of 5 studies,including 116 *** prevalence estimates of liver histopathological findings were hepatic steatosis 55.1%[95%confidence interval(CI):46.2-63.8],congestion of hepatic sinuses 34.7%(95%CI:7.9-68.4),vascular thrombosis 29.4%(95%CI:0.4-87.2),fibrosis 20.5%(95%CI:0.6-57.9),Kupffer cell hyperplasia 13.5%(95%CI:0.6-54.3),portal inflammation 13.2%(95%CI:0.1-48.8),and lobular inflammation 11.6%(95%CI:0.3-35.7).We also identified the presence of venous outflow obstruction,phlebosclerosis of the portal vein,herniated portal vein,periportal abnormal vessels,hemophagocytosis,and *** We found a high prevalence of hepatic steatosis and vascular thrombosis as major histological liver *** frequent findings included portal and lobular inflammation and Kupffer cell hyperplasia or *** studies are needed to establish the mechanisms and implications of these findings.

关键词： Pathology SARS-CoV-2 COVID-19 Autopsies Liver Liver biopsies

Management of nonalcoholic fatty liver disease:An evidence-based clinical practice review

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World Journal of Gastroenterology 2014年第34期20卷 12182-12201页

作者： Juan P Arab Roberto Candia Rodrigo Zapata Cristián Mu?oz Juan P Arancibia Jaime Poniachik Alejandro Soza francisco Fuster Javier Brahm Edgar Sanhueza Jorge Contreras M Carolina Cuellar Marco Arrese Arnoldo riquelme Departamento de Gastroenterología Escuela de MedicinaPontificia Universidad Católica de Chile8330024 SantiagoChile Sección de Gastroenterología Hospital del SalvadorEscuela de MedicinaUniversidad de Chile7500922 SantiagoChile Unidad de Gastroenterología Universidad del DesarrolloClínica Alemana7650568 SantiagoChile Unidad de Trasplante Hepático Hospital del SalvadorUnidad de GastroenterologíaClínica Las Lilas7510524 SantiagoChile Sección de Gastroenterología Departamento de MedicinaHospital Clínico Universidad de ChileChile8380456 SantiagoChile Sección de Gastroenterología Hospital Clínico Universidad de ChileEscuela de MedicinaUniversidad de Chile8380456 SantiagoChile Digestive Diseases Unit Clínica Re?aca2540364 Vi?a del MarChile Gastroenterology Department Clínica Las Condes6770128 SantiagoChile Centre for Medical Education Escuela de MedicinaPontificia Universidad Católica de Chile8330024 SantiagoChile

AIM: To build a consensus among Chilean specialists on the appropriate management of patients with nonalcoholic fatty liver disease (NAFLD) in clinical practice.

关键词： Nonalcoholic fatty liver disease Steatosis Consensus Evidence-based medicine Treatment

Optimal length of triple therapy for H pylori eradication in a population with high prevalence of infection in Chile

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World Journal of Gastroenterology 2007年第21期13卷 2967-2972页

作者： Arnoldo riquelme Alejandro Soza Cesar Pedreros Andrea Bustamante Felipe Valenzuela francisco Otarola Eduardo Abbott Marco Arellano Brenda Medina Alejandro Pattillo Douglas Greig Marco Arrese Antonio Rollan Department of Gastroenterology Pontificia Universidad Católica de Chile Hospital de Urgencia Asistencia Pública SantiagoChile Department of Internal Medicine Pontificia Universidad Católica de Chile

AIM:To compare the efficacy of 7-d versus 14-d triple therapy for the treatment of H pylori infection in Chile,with a prevalence of 73% in general population. METHODS:H pylori-infected patients diagnosed by rapid urease test,with non-ulcer dyspepsia or peptic ulcer disease were randomized to receive omeprazole 20 mg bid,amoxicillin 1 g bid,and clarithromycin 500 mg bid for 7 (OAC7) or 14 (OAC14) d. Primary outcome was eradication rate 6 wk after the treatment. Subgroup analysis was carried out considering the eradication rate among patients with or without peptic ulcer disease and eradication rate among smokers or non-smokers. RESULTS:One hundred and thirty-one patients were randomized to OAC7 (n = 69) or OAC14 (n = 62). The overall eradication rate (intention-to-treat) was 78.3% in OAC7 and 85.5% in OAC14 groups,without a significant difference (P =0.37). No significant difference in the eradication rate was found among the patients with peptic ulcer disease (n = 31) between the OAC7 group (85.7%) and OAC14 group (87.5%). However,smokers had an obviously lower eradication rate compared to non-smokers,particularly in the OAC7 group (57.1% in smokers vs 83.6% in non-smokers; P = 0.06). Adverse effects rate were similar between both groups. CONCLUSION:Short-term efficacy of triple therapy with OAC for 7 d is comparable to 14 d in this high-prevalence population. Longer follow-up,and studies focused to some subgroups of patients (smokers and non-ulcerpatients) are necessary to support widespread use of 7-d instead of 10-14-d triple therapy in a developing country like Chile.

关键词： Helicobacter pylori Antibiotic treatment Omeprazole Amoxicillin Clarithromycin Quasirandomized controlled trial