| 1 | Online Unbalance Detection and Diagnosis on Large Flexible Rotors by SVR and ANN trained by Dynamic Multibody Simulations显示文摘Multiple-stage steam turbine generators,like those found in nuclear power plants,pose special challenges with regards to mechanical unbalance diagnosis.Several factors contribute to a complex vibrational response,which can lead to incorrect assessments if traditional condition monitoring strategies are used without considering the mechanical system as a whole.This,in turn,can lead to prolonged machinery downtime.Several machine learning techniques can be used to integrally correlate mechanical unbalance along the shaft with transducer signals from rotor bearings.Unfortunately,this type of machinery has scarce data regarding faulty behavior.However,a variety of fault conditions can be simulated in order to generate these data using computational models to simulate the dynamic response of individual machines.In the present work,a multibody model of a 640MWsteam turbine flexible rotor is employed to simulate mechanical unbalance in several positions along the shaft.Synchronous components of the resulting vibration signals at each bearing are obtained and utilized as training data for two regression models designed for mechanical unbalance diagnosis.The first approach uses an artificial neural network and the second one utilizes a support vector regression algorithm.In order to test their performance,the stiffness of each bearing in the multibody simulation was altered between 50%and 150%of the training model values,random noise was added to the signal and several dynamic unbalance conditions were simulated.Results show that both approaches can reliably diagnose dynamic rotor unbalance even when there is a typical degree of uncertainty in bearing stiffness values. | Oscar García Peyrano Juan Vignolo Rodrigo Mayer Matías Marticorena | 2022 | Journal of Dynamics, Monitoring and Diagnostics2022，1，3： | 0 |
| 2 | Epidemiological, prevention and control updates of yellow fever outbreak in Brazil显示文摘Yellow fever is an acute viral disease endemic to tropical countries, like Brazil, where, since the 1940 s, has no significant documented outbreaks similar to that observed between 2016/2018(2 045 confirmed cases and 677 deaths; caused by the sylvatic form).The principal manipulating factors inciting this change were absence of appropriate vaccination campaigns and increased urbanization & population growth in forest areas, with prevalence of the virus in the species inhabiting of these areas.The 2016/2018 outbreaks exhibited incidence in areas with historically low or no yellow fever virus activity, triggering a surge in recorded deaths-mainly in the Southeastern states of Brazil.The Brazilian government aggressively responded, reforming the countries' prophylactic measures, including vaccine implementation-as of March, 2018, switching from the former double dose regimen of the vaccine, to a single dose protocol, deemed as adequate.Moreover, some states appropriated the fractionated dosage(1/5 of the standard dose), in foresight of potential vaccine shortages.To prevent the uprising of new sylvatic yellow fever cases in Brazil, it's obligatory the development of effective combative plans, including adaptation of prophylactic measures individually(use of repellents, protective clothing etc.), applicable vaccination campaigns in every endemic region, to raise awareness to locals and visitors alike.Notwithstanding these preventative strategies, the persistence of cases and the recent outbreaks in Brazil, highlight the possible ineffectiveness of combative measures.Based on these considerations, the objective of this review was to raise more awareness of the epidemiological impact of the disease in Brazil. | Marli do Carmo Cupertino Rebeca Garcia Andréia Patrícia Gomes Sérgio Oliveira de Paula Nicholas Mayers Rodrigo Siqueira-Batista | 2019 | Asian Pacific Journal of Tropical Medicine2019，12，2： | 0 |
| 3 | Decline in subarachnoid haemorrhage volumes associated with the first wave of the COVID- 19 pandemic显示文摘Background During the COVID-19 pandemic,decreased volumes of stroke admissions and mechanical thrombectomy were reported.The study’s objective was to examine whether subarachnoid haemorrhage(SAH)hospitalisations and ruptured aneurysm coiling interventions demonstrated similar declines.Methods We conducted a cross-sectional,retrospective,observational study across 6 continents,37 countries and 140 comprehensive stroke centres.Patients with the diagnosis of SAH,aneurysmal SAH,ruptured aneurysm coiling interventions and COVID-19 were identified by prospective aneurysm databases or by International Classification of Diseases,10th Revision,codes.The 3-month cumulative volume,monthly volumes for SAH hospitalisations and ruptured aneurysm coiling procedures were compared for the period before(1 year and immediately before)and during the pandemic,defined as 1 March-31 May 2020.The prior 1-year control period(1 March-31 May 2019)was obtained to account for seasonal variation.Findings There was a significant decline in SAH hospitalisations,with 2044 admissions in the 3 months immediately before and 1585 admissions during the pandemic,representing a relative decline of 22.5%(95%CI−24.3%to−20.7%,p<0.0001).Embolisation of ruptured aneurysms declined with 1170-1035 procedures,respectively,representing an 11.5%(95%CI−13.5%to−9.8%,p=0.002)relative drop.Subgroup analysis was noted for aneurysmal SAH hospitalisation decline from 834 to 626 hospitalisations,a 24.9%relative decline(95%CI−28.0%to−22.1%,p<0.0001).A relative increase in ruptured aneurysm coiling was noted in low coiling volume hospitals of 41.1%(95%CI 32.3%to 50.6%,p=0.008)despite a decrease in SAH admissions in this tertile.Interpretation There was a relative decrease in the volume of SAH hospitalisations,aneurysmal SAH hospitalisations and ruptured aneurysm embolisations during the COVID-19 pandemic.These findings in SAH are consistent with a decrease in other emergencies,such as stroke and myocardial infarction. | Thanh N Nguyen Diogo C Haussen Muhammad M Qureshi Hiroshi Yamagami Toshiyuki Fujinaka Ossama Y Mansour Mohamad Abdalkader Michael Frankel Zhongming Qiu Allan Taylor Pedro Lylyk Omer F Eker Laura Mechtouff Michel Piotin Fabricio Oliveira Lima Francisco Mont'Alverne Wazim Izzath Nobuyuki Sakai Mahmoud Mohammaden Alhamza R Al-Bayati Leonardo Renieri Salvatore Mangiafico David Ozretic Vanessa Chalumeau Saima Ahmad Umair Rashid Syed Irteza Hussain Seby John Emma Griffin John Thornton Jose Antonio Fiorot Rodrigo Rivera Nadia Hammami Anna M Cervantes-Arslanian Hormuzdiyar H Dasenbrock Huynh Le Vu Viet Quy Nguyen Steven Hetts Romain Bourcier Romain Guile Melanie Walker Malveeka Sharma Don Frei Pascal Jabbour Nabeel Herial Fawaz Al-Mufti Atilla Ozcan Ozdemir Ozlem Aykac Dheeraj Gandhi Chandril Chugh Charles Matouk Pascale Lavoie Randall Edgell Andre Beer-Furlan Michael Chen Monika Killer-Oberpfalzer Vitor Mendes Pereira Patrick Nicholson Vikram Huded Nobuyuki Ohara Daisuke Watanabe Dong Hun Shin Pedro SC Magalhaes Raghid Kikano Santiago Ortega-Gutierrez Mudassir Farooqui Amal Abou-Hamden Tatsuo Amano Ryoo Yamamoto Adrienne Weeks Elena A Cora Rotem Sivan-Hoffmann Roberto Crosa Markus Möhlenbruch Simon Nagel Hosam Al-Jehani Sunil A Sheth Victor S Lopez Rivera James E Siegler Achmad Fidaus Sani Ajit S Puri Anna Luisa Kuhn Gianmarco Bernava Paolo Machi Daniel G Abud Octavio M Pontes-Neto Ajay K Wakhloo Barbara Voetsch Eytan Raz Shadi Yaghi Brijesh P Mehta Naoto Kimura Mamoru Murakami Jin Soo Lee Ji Man Hong Robert Fahed Gregory Walker Eiji Hagashi Steve M Cordina Hong Gee Roh Ken Wong Juan F Arenillas Mario Martinez-Galdamez Jordi Blasco Alejandro Rodriguez Vasquez Luisa Fonseca M Luis Silva Teddy Y Wu Simon John Alex Brehm Marios Psychogios William J Mack Matthew Tenser Tatemi Todaka Miki Fujimura Roberta Novakovic Jun Deguchi Yuri Sugiura Hiroshi Tokimura Rakesh Khatri Michael Kelly Lissa Peeling Yuichi Murayama Hugh Stephen Winters Johnny Wong Mohamed Teleb Jeremy Payne Hiroki Fukuda Kosuke Miyake Junsuke Shimbo Yusuke Sugimura Masaaki Uno Yohei Takenobu Yuji Matsumaru Satoshi Yamada Ryuhei Kono Takuya Kanamaru Masafumi Morimoto Junichi Iida Vasu Saini Dileep Yavagal Saif Bushnaq Wenguo Huang Italo Linfante Jawad Kirmani David S Liebeskind Viktor Szeder Ruchir Shah Thomas G Devlin Lee Birnbaum Jun Luo Anchalee Churojana Hesham E Masoud Carlos Ynigo Lopez Brendan Steinfort Alice Ma Ameer E Hassan Amal Al Hashmi Mollie McDermott Maxim Mokin Alex Chebl Odysseas Kargiotis Georgios Tsivgoulis Jane G Morris Clifford J Eskey Jesse Thon Leticia Rebello Dorothea Altschul Oriana Cornett Varsha Singh Jeyaraj Pandian Anirudh Kulkarni Pablo M Lavados Veronica V Olavarria Kenichi Todo Yuki Yamamoto Gisele Sampaio Silva Serdar Geyik Jasmine Johann Sumeet Multani Artem Kaliaev Kazutaka Sonoda Hiroyuki Hashimoto Adel Alhazzani David Y Chung Stephan A Mayer Johanna T Fifi Michael D Hill Hao Zhang Zhengzhou Yuan Xianjin Shang Alicia C Castonguay Rishi Gupta Tudor G Jovin Jean Raymond Osama O Zaidat Raul G Nogueira SVIN COVID-19 Registry,the Middle East North Africa Stroke and Interventional Neurotherapies Organization(MENA-SINO),Japanese Society of Vascular and Interventional Neurology Society(JVIN) | 2021 | Stroke & Vascular Neurology2021，6，4： | 0 |
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