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In-hand manipulation of a circular dynamic object by soft fingertips without angle measurement

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Science China(Information Sciences) 2021年第5期64卷 193-208页

作者： R.garcia-RODRIGUEZ V.PARRA-VEGA Aeronautical Engineering Program and Postgraduate Program in Aerospacial Engineering Universidad Politecnica Metropolitana de Hidalgo Robotics and Advanced Manufacturing Department Research Center for Advanced Studies (CINVESTAV)

A multi-fingered robotic hand with curved fingertips enables contact re-positioning without reattaching at the expense of fingertip rolling. This rolling stands for a characteristic that facilitates dexterous manipulation but results in an algebraically complex dynamic model subject to such constraints. The hemispherical shape of fingertips allows a dexterous manipulation when controlling the tangent forces, which are essential to rotate object. However, the measurement of the object angle in practice requires tactile-optical sensing. In this paper, considering robotic fingers with curved soft tips, we propose a feedback control that ensures optimal dynamical grasping of a circular rigid object. It is shown that the collaboration of the contact forces, to get a minimum pose of internal forces, and the tangential forces, to induce the conditions for assuring the grasp closure, is necessary to get a skillful manipulation. In this case, the orientation control of a circular object to the desired angle while avoiding direct measurement of the object angle is presented. Stability conditions of the system are presented in the sense of stability-in-the-manifold. Finally, representative simulations are shown and discussed.

关键词： optimal grasping manipulation soft-fingertips circular object stability-in-the-manifold

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“手”的成语

孔子学院（中西文对照版） 2024年第1期 30-31页

作者：宋雨潺小康(翻译) 不详

在汉语中,“手”是一个重要的汉字,它不仅能生成许多新的汉字,还能组成众多成语。“扌”,是“手”的变形,作为偏旁部首,可以生成很多汉字,如“打”“拉”“推”等。这些汉字都与手的动作有关,一般作动词使用。

关键词：偏旁部首成语汉字动词使用生成

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有趣的网络流行语

孔子学院（中西文对照版） 2024年第1期 32-33页

作者：廖叶小康(翻译) 不详

在日常生活中,你是否经常会听到朋友说一些网络流行语,而你不解其意甚至还略感尴尬呢?今天,我们选择了一些生动有趣的网络流行语,除了能答疑解惑外,还可以让我们感受语言的活力和变迁。

关键词：网络流行语生动有趣答疑解惑日常生活

Meteorological drought features in northern and northwestern parts of Mexico under different climate change scenarios

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Journal of Arid Land 2017年第1期9卷 65-75页

作者： Carlos ESCALANTE-SANDOVAL Pedro NUNEZ-garcia Faculty of Engineering National Autonomous University of Mexico Cd. Universitaria Coyoacan 04510 Mexico

Meteorological drought has been an inevitable natural disaster throughout Mexican history and the northern and northwestern parts of Mexico（i.e., the studied area）, where the mean annual precipitation（MAP） is less than 500 mm, have suffered even more from droughts in the past. The aim of this study was to conduct a meteorological drought analysis of the available MAP data（1950–2013） from 649 meteorological stations selected from the studied area and to predict the drought features under the different IPCC-prescribed climate change scenarios. To determine the long-term drought features, we collected 1×10~4 synthetic samples using the periodic autoregressive moving average（PARMA） model for each rainfall series. The simulations first consider the present prevailing precipitation conditions（i.e., the average from 1950 to 2013） and then the precipitation anomalies under IPCC-prescribed RCP 4.5 scenario and RCP 8.5 scenario. The results indicated that the climate changes under the prescribed scenarios would significantly increase the duration and intensity of droughts. The most severe impacts may occur in the central plateau and in the Baja California Peninsula. Thus, it will be necessary to establish adequate protective measures for the sustainable management of water resources in these regions.

关键词： meteorological drought synthetic simulation climate change water stress evapotranspiration

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Control design of an unmanned hovercraft for agricultural applications

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International Journal of Agricultural and Biological Engineering 2015年第2期8卷 72-79页

作者： Deyka I garcia Warren N White Department of Mechanical Engineering Universidad Tecnológica de PanamáPanamá0819-07289Panamá Department of Mechanical and Nuclear Engineering Kansas State UniversityManhattanKS 66506USA

The efficient and precise application of agricultural materials such as fertilizer or herbicide can be greatly facilitated by autonomous *** is especially important under difficult conditions at remote *** purpose of this work is to develop an accurate nonlinear controller using a direct Lyapunov approach to ensure stability of an unmanned hovercraft prototype used for the execution of these agricultural *** a craft constitutes an underactuated system which has fewer actuators than degrees of *** proposed closed loop system is simulated to demonstrate that a control law can stabilize both the actuated and unactuated degrees of freedom of the *** is shown that the position and orientation of the hovercraft achieve high dynamic and steady performance.

关键词： controller direct Lyapunov method nonholonomic constraint underactuated system unmanned hovercraft

Effect of caffeine in the intraventricular hemorrhage of the preterm newborn

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Neural Regeneration Research 2023年第9期18卷 1942-1943页

作者： Pilar Alves-Martinez Monica garcia-Alloza Division of Physiology School of MedicineUniversidad de CadizCadizSpain Biomedical Research and Innovation Institute of Cádiz(INiBICA)Research Unit Puerta del Mar University Hospital University of CadizCadizSpain

There are around 15 million preterm newborns(PT) eve ry year(Atienza-Navarro et al., 2020).With these figures in mind,prematurity represents a major health problem worldwide and it is a leading cause of infant mortality,accounting for up to 35%of all deaths among newborns(Atienza-Navarro et al.,2020) and up to 18% of the deaths among children under 5 years of age.

关键词： newborn infant deaths

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Dynamic Modeling, Testing, and Stability Analysis of an Ornithoptic Blimp

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Journal of Bionic Engineering 2011年第4期8卷 375-386页

作者： John Dietl Thomas Herrmann Gregory Reich Ephrahim garcia Sibley School of Mechanical and Aerospace Engineering Cornell University Ithaca New York USA Air Force Research Laboratory Wright-Patterson AFB OH 45433-7542 USA

In order to study omithopter flight and to improve a dynamic model of flapping propulsion, a series 0f tests are conducted on a flapping-wing blimp. The blimp is designed and constructed from mylar plastic and balsa wood as a test platform for aerodynamics and flight dynamics. The blimp, 2.3 meters long and 420 gram mass, is propelled by its flapping wings. Due to buoyancy the wings have no lift requirement so that the distinction between lift and propulsion can be analyzed in a flight platform at low flight speeds. The blimp is tested using a Vicon motion tracking system and various initial conditions are tested including accelerating flight from standstill, decelerating from an initial speed higher than its steady state, and from its steady-state speed but disturbed in pitch angle. Test results are used to estimate parameters in a coupled quasi-steady aerodynamics/Newtonian flight dynamics model. This model is then analyzed using Floquet theory to determine local dynamic modes and stability. It is concluded that the dynamic model adequately describes the vehicle＇s nonlinear behavior near the steady-state velocity and that the vehicle＇s linearized modes are akin to those of a fixed-wing aircraft.

关键词： omithopter blimp flight dynamics stability analysis

Prediabetes and type 2 diabetes implication in central proliferation and neurogenesis

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Neural Regeneration Research 2015年第1期10卷 28-29页

作者： Carmen Infante-garcia Juan Jose Ramos-Rodriguez Monica garcia-Alloza Division of Physiology School of MedicineUniversidad de CádizCádiz 11003Spain

Type 2 diabetes （T2D） is an important risk factor for developing dementias, including Alzheimer＇s disease （AD）. Hyperinsulin- emia and glucose intolerance, as features of T2D, might increase the neurodegeneration process, synaptic loss and brain atrophy, leading to cognitive impairment observed in AD. Also, adult neurogenesis seems to be impaired in AD models. Therefore, we have studied morphological alterations, cell proliferation and neurogenesis in the central nervous system （CNS） from a classical model of T2D, the db/db mouse, and in a prediabetes insulin-resistant model, obtained after long-term high fat diet （HFD） administration to C57B1/6 mice. Db/db mice showed an age-dependent cortical and hippocampal atrophy, whereas in HFD mice cortex and hippocampus were preserved. Neurogen- esis and cell proliferation were increased in young db/db mice, when compared with control mice, whereas no differences were detected in the prediabetic model. We also detected significant correlations between metabolic parameters and central atrophy, altered proliferation and neurogenesis in the central nervous system. Altogether these data support that glycaemia control in elderly patients, could help to control central alterations and improve dementia prognosis.

关键词： Prediabetes and type 2 diabetes implication in central proliferation and neurogenesis

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Classifying Metarational Stabilities in Conflicts

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Journal of Systems Science and Systems Engineering 2019年第3期28卷 265-284页

作者： Amanda garcia Keith W.Hipel Amer Obeidi Department of Systems Design Engineering University of WaterlooWaterloo OntarioCanada Department of Management Sciences University of WaterlooWaterloo OntarioCanada

New solution concepts for n-decision maker conflicts based on generalized metarationalities for modelling possible human behaviour under conflict are proposed.A classification of these solution concepts,also called stability definitions,is presented both to simplify understanding and to illustrate important differences among different stability *** relationships among solution concepts are explored and new,more specific results are obtained in the comparison among existing stability concepts and the newly proposed *** informative example is used to demonstrate the applicability and insights of these solution concepts.

关键词： Graph model for conflict resolution generalized metarationalities stability criteria decisionmaking