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Adaptive control of a class of nonlinear time-varying systems with multiple models

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Control Theory and Technology 2016年第4期14卷 323-334页

作者： Koshy george Karpagavalli sUBRAMANIAN PEs Centre for Intelligent systems Department of Telecommunication Engineering PES Institute of Technology Bangalore India PEs Centre for Intelligent systems Department of Electronics and Communication Engineering PES University Bangalore India

The adaptive control of nonlinear systems that are linear in the unknown but time-varying parameters are treated in this paper. since satisfactory transient performance is an important factor, multiple models are required as these parameters change abruptly in the parameter space. In this paper we consider both the multiple models with switching and tuning methodology as well as multiple models with second level adaptation for this class of systems. We demonstrate that the latter approach is better than the former.

关键词： Nonlinear time-varying systems adaptive control multiple models

Multicellular systems Biology: Quantifying Cellular Patterning and Function in Plant Organs Using Network science

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Molecular Plant 2019年第6期12卷 731-742页

作者： george W.Bassel school of Biosciences University of Birmingham Birmingham B15 2TT UK

Organ function is at least partially shaped and constrained by the organization of their constituent cells. Extensive investigation has revealed mechanisms explaining how these patterns are generated, with less being known about their functional relevance. In this paper, a methodology to discretize and quantitatively analyze cellular patterning is described. By performing global organ-scale cellular interaction mapping, the organization of cells can be extracted and analyzed using network science. This provides a means to take the developmental analysis of cellular organization in complex organisms beyond qualitative descriptions and provides data-driven approaches to inferring cellular function. The bridging of a structure- function relationship in hypocotyl epidermal cell patterning through global topological analysis provides support for this approach. The analysis of cellular topologies from patterning mutants further enables the contribution of gene activity toward the organizational properties of tissues to be linked, bridging molecular and tissue scales. This systems-based approach to investigate multicellular complexity paves the way to uncovering the principles of complex organ design and achieving predictive genotypephenotype mapping.

关键词： organ network connectivity transport tissue topology connectome

The crossed phrenic phenomenon

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Neural Regeneration Research 2017年第6期12卷 845-864页

作者： Michael george Zaki Ghali Department of Neurobiology & Anatomy Drexel University College of Medicine

The cervical spine is the most common site of traumatic vertebral column injuries. Respiratory insufficiency constitutes a significant proportion of the morbidity burden and is the most common cause of mortality in these patients. In seeking to enhance our capacity to treat specifically the respiratory dysfunction following spinal cord injury, investigators have studied the “crossed phrenic phenomenon”, wherein contraction of a hemidiaphragm paralyzed by a complete hemisection of the ipsilateral cervical spinal cord above the phrenic nucleus can be induced by respiratory stressors and recovers spontaneously over time. strengthening of latent contralateral projections to the phrenic nucleus and sprouting of new descending axons have been proposed as mechanisms contributing to the observed recovery. We have recently demonstrated recovery of spontaneous crossed phrenic activity occurring over minutes to hours in C_1-hemisected unanesthetized decerebrate rats. The specific neurochemical and molecular pathways underlying crossed phrenic activity following injury require further clarification. A thorough understanding of these is necessary in order to develop targeted therapies for respiratory neurorehabilitation following spinal trauma. Animal studies provide preliminary evidence for the utility of neuropharmacological manipulation of serotonergic and adenosinergic pathways, nerve grafts, olfactory ensheathing cells, intraspinal microstimulation and a possible role for dorsal rhizotomy in recovering phrenic activity following spinal cord injury.

关键词： crossed traumatic spontaneously olfactory diaphragm descending vertebral spine sprouting minutes

The Villafranchian carnivoran guild of Greece:implications for the fauna,biochronology and paleoecology

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Integrative Zoology 2014年第4期9卷 444-460页

作者： george D.KOUFOs Department of Geology Aristotle University of ThessalonikiThessalonikiGreece

Knowledge on the Villafranchian faunas of Greece was limited for a long time,but over the past 3 decades several new fossiliferous sites have been discovered and new material has been *** carnivores constitute a remarkable part of this material and their study has provided useful information for the taxonomy,chronology and *** Villafranchian carnivoran guild includes numerous taxa belonging to various *** of them are interesting as they are differentiated from the other Eurasian *** cover the entire Villafranchian but the mass is known from the Middle to the Epi-Villafranchian(EVC).Despite the discontinuous data,they provide useful biochronological *** coexistence of Pliocrocuta perrieri and Pachycrocuta brevirostris in the locality of Gerakarou 1 is strong evidence for the Middle Villafranchian(MVC)/Late Villafranchian(LVC)*** composition of the Villafranchian carnivores suggests that the canids predominate,while the felids,hyenids and mustelids are well represented;the ursids are represented by a single taxon,the well-known Ursus etruscus,which seems to be common during the entire *** carnivoran guild structure and the multivariate analysis of the Greek Villafranchian carnivoran assemblages(MVC,LVC and EVC)in comparison with modern assembalges from open and closed environments indicate a relatively open landscape,which is in agreement with previous results for the Villafranchian of *** the EVC there is a faunal renewal that is related to a more open and dry environment,like savannah bushland/grassland.

关键词： biochronology carnivore Greece paleoecology Villafranchian

Capital injections with negative surplus and delays: models and analysis

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Control Theory and Technology 2014年第2期12卷 163-172页

作者： Zhuo JIN george YIN Centre for Actuarial studies Department of Economics The University of Melbourne VIC 3010 Australia Department of Mathematics Wayne State University Detroit Michigan 48202 U.S.A.

This work develops a new model to deal with the scenario that some companies can still run business even the surplus falls below zero temporarily. With such a scenario in mind, we allow the surplus process to continue in this negative-surplus period, during which capital injections will be ordered to assist in the stabilization of financial structure, until the financial status becomes severe enough to file bankruptcy. The capital injections will be modeled as impulse controls. By introducing the capital injections with time delays, optimal dividend payment and capital injection policies are considered. Using the dynamic programming approach, the value function obeys a quasi-variational inequality. With delays in capital injections, the company will be exposed to the risk of bankruptcy during the delay period. In addition, the optimal dividend payment and capital injection strategies should balance the expected cost of the possible capital injections and the time value of the delay periods. This gives rise to a stochastic control problem with mixed singular and delayed impulse controls. Under general assumptions, the lower capital injection barrier is determined, where bankruptcy occurs. The closed-form solution to the value function and corresponding optimal policies are obtained.

关键词： stochastic control Capital injection Dividend policy Delayed impulse control singular contro

Gravitational wave research using pulsar timing arrays

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National science Review 2017年第5期4卷 707-717页

作者： george Hobbs shi Dai Australia Telescope National Facility CSIRO

A pulsar timing array(PTA) refers to a program of regular, high-precision timing observations of a widely distributed array of millisecond pulsars. Here we review the status of the three primary PTA projects and the joint International Pulsar Timing Array project. We discuss current results related to ultra-low-frequency gravitational wave searches and highlight opportunities for the near future.

关键词： pulsars gravitational waves radio astronomy

Understanding practice patterns of glaucoma sub-specialists in India

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International Journal of Ophthalmology(English edition) 2017年第10期10卷 1580-1585页

作者： Nikhil s.Choudhari Vanita Pathak-Ray sushmita Kaushik Prateep Vyas Ronnie george V s T Glaucoma Centre Dr.Kallam Anji Reddy CampusL V Prasad Eye Institute Advanced Eye Centre Postgraduate Institute of Medical Education and Research Centre for sight Glaucoma Society of India Department of Glaucoma Medical Research Foundation

AIM：To obtain information on the prevailing practice patterns of glaucoma specialists in ***：Glaucoma specialists attending the Annual Conference of the Glaucoma society of India（GsI）were *** survey,conducted in 2013,was based on an interactive audience response ***：The information was obtained from 146 glaucoma *** half（n=83;57%）had≥10y of experience in managing glaucoma and were in institutional practice（n=74,51%）.Goldmann applanation tonometry was preferred by 103（72%）specialists whilst n=25（17.4%）used non-contact *** gonioscopy was favoured by two-thirds（n=90,66%）whereas stereoscopic optic disc examination and visual fields using Humphrey perimeter was performed by a majority of the specialists surveyed（n=115,86%and n=114;83%respectively）.Nearly three quarter specialists（n=96;72%）preferred optical coherence tomography for *** primary choice for treatment of angle closure disease and primary open angle glaucoma was laser（iridotomy,n=117;93%）and medical management（prostaglandin analogue,n=104;78%）,*** only a third of the specialists surveyed（n=37;28%）were performing both trabeculectomy and implantation of a glaucoma drainage device and about half（n=64;47%）were not operating on congenital glaucoma at ***：This survey has found conformance with preferred practice patterns in several areas of diagnosisand management of glaucoma,but there was diversity in a few *** information is a significant step towards improvement of glaucoma care in India,including planning for future strategies.

关键词： glaucoma practice patterns glaucoma specialists glaucomatologist audience response system survey

Time derivative of earthquake acceleration

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Earthquake Engineering and Engineering Vibration 2005年第1期4卷 1-16页

作者： george C. Lee Multidisciplinary Center for Earthquake Engineering Research University at Buffalo Buffalo NY 14261-0025 USAProfessor

Unlike acceleration, velocity, and displacement, the time derivative ofacceleration (TDoA) of ground motion has not been extensively studied. In this paper, the basiccharacteristics of TDoA are evaluated based on records from the 1999 Chi-Chi, earthquake (Mw 7.6)and one of its aftershocks (Mw 6.2). It is found that the maximum TDoA at a free-field station wasover 31,200 cm/s3 (31.8 g/s); and the duration of 'strong' TDoA, between the first and the last timepoints exceeding 2,000 cm/s3 (2 g/s), was almost one minute near the epicenter area. since groundTDoA sensors are not commonly available, the time series are calculated by direct numericaldifferentiation of acceleration time series. Relative error analysis shows that the error isnon-transitive and total error is within 4%. The density function of TDoA amplitude, frequencycontent and spatial distribution of peak ground jerk (PGJ) are evaluated. The study also includesexamination of some TDoA responses from a seven-story building and comparison of ground TDoA withthe limit TDoA used in the transportation industry for ride comfort. some potential impacts of TDoAon humans have also been reviewed.

关键词： time derivation of acceleration peak ground jerk acceleration time series earthquake ground motion earthquake effect on human activities

Impact of sGLT2 inhibitors on major clinical events and safety outcomes in heart failure patients:a meta-analysis of randomized clinical trials

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Journal of Geriatric Cardiology 2021年第10期18卷 783-795页

作者： george Bazoukis stamatis s.Papadatos Costas Thomopoulos Gary Tse stefanos Cheilidis Konstantinos Tsioufis Dimitrios Farmakis Department of Cardiology Larnaca General HospitalLarnacaCyprus Department of Anatomy Histology and EmbryologyMedical SchoolUniversity of IoanninaIoanninaGreece Department of Cardiology Helena Venizelou HospitalAthensGreece Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease Department of CardiologyTianjin Institute of CardiologySecond Hospital of Tianjin Medical UniversityTianjinChina University of Cyprus Medical school NicosiaCyprus First Cardiology Clinic Hippokration HospitalAthens UniversityAthensGreece

BACKGROUND sodium-glucose co-transporter-2 inhibitors(sGLT2i)significantly reduce the risk of cardiovascular(CV)and renal adverse events in patients with diabetes mellitus,heart failure(HF)and/or chronic kidney *** performed a meta-analysis to explore the impact of several different sGLT2i on all-cause mortality,CV mortality,HF hospitalizations and the combined outcome CV death/HF hospitalization in HF patients across the spectrum of left ventricular ejection fraction(LVEF)*** A systematic search in MEDLINE database and Cochrane library through March 2021 was performed without *** clinical trials that provided data about the impact of sGLT2i on all-cause mortality,CV mortality,HF hospitalizations or the combined outcome of CV death/HF hospitalization in HF patients were included.A random effects model was used for calculating the effect *** Nine studies(n=16,723 patients,mean age:65.9 years,males:70.7%)were included in the quantitative *** to placebo,sGLT2i use was associated with 14%lower risk of all-cause mortality[hazard ratio(HR)=0.86,95%CI:0.78−0.94,I^(2)=0,P=0.0008],32%lower risk of HF hospitalizations(HR=0.68,95%CI:0.62−0.74,I^(2)=0,Psk of CV mortality(HR=0.86,95%CI:0.77−0.95,I^(2)=0,P=0.003)and 26%lower risk of CV death/HF hospitalization(HR=0.74,95%CI:0.68−0.80,I^(2)=0,Psafety outcomes,our data revealed no significant differences between sGLT2i and placebo groups in drug related discontinuations,amputations,severe hypoglycemia,hypotension,volume depletion,ketoacidosis and genital *** contrast,a protective role of sGLT2i against placebo was found for serious adverse events and acute kidney *** In patients with HF,regardless of LVEF phenotype,all sGLT2i had an excellent safety profile and significantly reduced the risk of all-cause mortality,CV mortality,HF hospitalizations and CV deaths/HF hospitalizations compared to placeb

关键词： patients clinical protective