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The Merits of Passive compliant Joints in Legged Locomotion： Fast Learning, Superior Energy Efficiency and Versatile Sensing in a Quadruped Robot

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Journal of Bionic Engineering 2017年第1期14卷 1-14页

作者： Matej hoffmann Jakub Simanek icub Facility Istituto Italiano di Tecnologia Genova 16123 Italy Artificial Intelligence Laboratory Department of lnformatics University of Zurich Zurich 8050 Switzerland Department of Measurement Faculty of Electrical Engineering Czech Technical University in Prague Prague 166 27 Czech Republic

A quadruped robot with four actuated hip joints and four passive highly compliant knee joints is used to demonstrate the potential of underactuation from two standpoints： learning locomotion and perception. First, we show that：（i） forward locomotion on flat ground can be learned rapidly （minutes of optimization time）; （ii） a simulation study reveals that a passive knee configuration leads to faster, more stable, and more efficient locomotion than a variant of the robot with active knees; （iii） the robot is capable of learning turning gaits as well. The merits of underactuation （reduced controller complexity, weight, and energy consumption） are thus preserved without compromising the versatility of behavior. Direct optimization on the reduced space of active joints leads to effective learning of model-free controllers. Second, we find passive compliant joints with po- tentiometers to effectively complement inertial sensors in a velocity estimation task and to outperform inertial and pressure sensors in a terrain detection task. Encoders on passive compliant joints thus constitute a cheap and compact but powerful sensing device that gauges joint position and force/torque, and -- if mounted more distally than the last actuated joints in a legged robot -- it delivers valuable information about the interaction of the robot with the ground.

关键词： legged robots underactuated robots compliant joints learning locomotion force and tactile sensing haptic terrain classification

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A force-compensated compliant MEMS-amplifier with electrostatic anti-springs

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Microsystems & Nanoengineering 2023年第3期9卷 235-244页

作者： Philip Schmitt Martin hoffmann Microsystems Technology Ruhr-Universität BochumUniversitätsstr.15044801 BochumGermany

In this paper,an electrostatic compliant mechanical amplifier intended for force-compensated displacement amplification in MEMS sensor applications is ***,mechanical transformers that enhance a small input displacement into a large output displacement generate large forces at the input of the *** microsystem proposed here allows for the reduction and compensation of the input stiffness of the amplifier and any mechanical components connected to it while providing a constant amplification ratio at the same *** amplifying mechanism features bidirectional electrostatic anti-springs enabling the control of the stiffness by applying a constant Dc *** electrode design of the anti-springs and its influence on the force-displacement characteristic,the side instability and the maximal displacement are studied through analytical approaches and supported by FEA and by *** on the derived models,a compliant electromechanical amplifier is developed,featuring an amplification ratio of *** this amplifier the initial input stiffness of 422 N/m could be reduced to 6.8 N/m by applying a voltage of 100 *** an additional application,we show how the amplifier can be used as a mechanical force sensor with tuneable sensitivity,where the forces at the input are transformed into large output *** experiments,we show how the sensitivity can be adjusted and increased by a factor of 25 by applying a voltage at the anti-springs.

关键词： amplifier electrostatic spring

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On the Simulation of Industrial Gas Dynamic Applications with the Disconti- nuous Galerkin Spectral Element Method

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Journal of Thermal Science 2016年第3期25卷 250-257页

作者： F. Hempert M. hoffmann U. Iben c.-D. Munz Robert-Bosch GmbH Robert-Bosch campus 1 71272 Renningen Germany Institute of Aerodynamics and Gas Dynamics Pfaffenwaldring 21 70569 Stuttgart Germany

In the present investigation, we demonstrate the capabilities of the discontinuous Galerkin spectral element method for high order accuracy computation of gas dynamics. The internal flow field of a natural gas injector for bivalent combustion engines is investigated under its operating conditions. The simulations of the flow field and the aeroacoustic noise emissions were in a good agreement with the cxperirnental data. we tested several shockcapturing techniques for the discontinuous Galerkin scheme. Based on the validated framework, we analyzed the development of the supersonic jets during different opening procedures of a compressed natural gas injector. The results suggest that a more gradual injector opening decreases the noise emission.

关键词： Discontinuous Galerkin natural gas injection supersonic under-expanded jet high performance computing

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Using a Surface Plasmon Resonance Biosensor for Rapid Detection of Salmonella Typhimurium in chicken carcass

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Journal of Bionic Engineering 2008年第3期5卷 239-246页

作者： Yu-bin Lan Shi-zhou wang Yong-guang Yin w. clint hoffmann Xian-zhe Zheng USDA-ARS College Station TX77845 USA Department of Environmental and Occupational Health Texas A＆M University College Station TX 77845 USA college of Biological and Agricultural Engineering Jilin University Changchun 130022 P. R. China college of Engineering Northeast Agricultural University Harbin 150030 P. R. China

chicken is one of the most popular meat products in the world. Salmonella Typhimurium is a common foodbome pathogens associated with the processing of poultry. An optical Surface Plasmon Resonance （SPR） biosensor was sensitive to the presence of Salmonella Typhimurium in chicken carcass. The Spreeta biosensor kits were used to detect Salmonella Typhimurium on chicken carcass successfully. A taste sensor like electronic tongue or biosensors was used to basically ＂taste＂ the object and differentiated one object from the other with different taste sensor signatures. The surface plasmon resonance biosensor has potential for use in rapid, real-time detection and identification of bacteria, and to study the interaction of organisms with dif- ferent antisera or other molecular species. The selectivity of the SPR biosensor was assayed using a series of antibody con- centrations and dilution series of the organism. The SPR biosensor showed promising to detect the existence of Salmonella Typhimurium at 1 x 106 cFU/ml. Initial results show that the SPR biosensor has the potential for its application in pathogenic bacteria monitoring. However, more tests need to be done to confirm the detection limitation.

关键词： biosensor Salmonella Typhimurium food safety chicken carcass detection limitation Surface Plasmon Resonance

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Genetic variation and potential coinfection of wolbachia among widespread Asian citrus psyllid (Diaphorina citri Kuwayama) populations

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Insect Science 2019年第4期26卷 671-682页

作者： chia-ching chu Mark hoffmann w. Evan Braswell Kirsten S. Pelz-Stelinski Department of Entomology and Nematology University of Florida Gainesville Florida USA citrus Research and Education center University of Florida Lake Alfred Florida USA 3Department of Horticultural Sciences North Carolina State University Raleigh North Carolina USA center for Plant Health Science and Technology USDA APHIS Edinburg Texas USA

wolbachia can profoundly influence the survival, reproduction, and defenses of insect hosts. These interactions could potentially be harnessed for managing pests or insecttransmitted diseases. Diaphorina citri Kuwayama is a phloem-feeding pest capable of transmitting the putative causal agent of citrus greening, candidatus Liberibacter asiaticus (cLas). Like many insects, D. citri is also infected with wolbachia (wDi). Recent studies indicate that the relative abundance of wDi could be associated with the abundance of cLas, and that wDi may contribute to regulating expression of phage lytic cycle genes in cLas, suggesting the need for better understanding of wDi biology in general. This study investigated the genetic diversity of wDi among D. citri in populations spanning eleven countries and two U.S. territories. Six wolbachia genes, wsp, ***, gatB, and hep A, were sequenced and compared across samples. Two prevalent wDi strains were identified across the samples, and screening of clone libraries revealed possible coinfection of wDi strains in specific populations. D. citri mitochondrial cytochrome oxidase subunit I gene (mtcOI) were more divergent between D. citri populations that were infected with different wDi strains or had different infection statuses (single infection vs. coinfection). while we could not eliminate the possibility that maternal transmission may contribute to such patterns, it is also possible that wDi may induce cytoplasmic incompatibility in their host. These fin dings should contribute to the understanding of wDi population ecology, which may facilitate manipulation of this endosymbiont for management of citrus greening disease worldwide.

关键词： bacteria genetic diversity Huanglongbing plant disease superinfection vertically transmitted endosymbionts

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Patient-derived skin fibroblasts as a model to study frontotemporal lobar degeneration

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Neural Regeneration Research 2022年第12期17卷 2669-2671页

作者： Dorit hoffmann Annakaisa Haapasalo A.I.Virtanen Institute for Molecular Sciences University of Eastern FinlandKuopioFinland

Frontotemporal lobar degeneration(FTLD)is one of the most common causes of early-onset dementia in patients under the age of 65 *** is a clinically,genetically,and neuropathologically heterogeneous group of neurodegenerative syndromes,causing atrophy in the temporal and frontal lobes of the *** is accompanied by progressive cognitive dysfunction,behavioral changes,difficulties in understanding or producing speech,and often also neuropsychiatric symptoms(Haapasalo and Remes,2015).Moreover,the clinical,genetic,and neuropathological features of FTLD may overlap with those of amyotrophic lateral sclerosis(ALS).Motor dysfunction is commonly present in FTLD patients and a portion of ALS patients experience frontal and temporal lobe dysfunction(Smith et al.,2019).

关键词： degeneration patients

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Food safety management and regulation:International experiences and lessons for china

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Journal of Integrative Agriculture 2015年第11期14卷 2218-2230页

作者： L Unnevehr V hoffmann Agricultural and consumer Economics University of Illinois Urbana-Champaign International Food Policy Research Institute

china is experiencing rapid urbanization, changes in diets, and modernization of food retailing and production. In this context, food safety can become a greater concern for a variety of reasons. The purpose of this article is to review the international experiences and lessons regarding food safety management, regulation, and consumer behavior, with the goal of identifying how to improve food safety in middle income countries such as china. International experience in addressing food safety provides two general kinds of lessons. First, a middle-income country such as china needs to develop the capacity to carry out risk analysis in order to better focus public resources on the most important risks. Second, it will be important to leverage market incentives so as to make the best use of limited public capacity to enforce standards. Inter- national experiences show that food safety management is feasible where market incentives exist, and that public-private partnerships can support the process of improving food safety management. Market incentives require effective consumer or buyer demand, mechanisms to identify and reward quality, and supply chain coordination. Public efforts can be targeted to supporting these market developments for the risks that are the greatest burden to public health.

关键词： food safety regulation supply chain coordination risk analysis

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Beyond Membranes:The Evolution of Plant Lipid Signaling

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Molecular Plant 2020年第7期13卷 952-954页

作者： Susanne hoffmann-Benning Department of Biochemistry and Molecular Biology Michigan State UniversityEast LansingMIUSA

Lipids have many essential functions in plants:They are membrane components and as such play an important role in compartmentation of the cell,membrane curvature,and formation of lipid rafts/microdomains;they participate in vesicle formation and trafficking,and act as a barrier to unrestricted trafficking of *** are also important intermediates in the biosynthesis of secondary metabolites and storage *** more interesting is their role in signaling.

关键词： Lipid Plant curvature

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Review of agricultural spraying technologies for plant protection using unmanned aerial vehicle(UAV)

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International Journal of Agricultural and Biological Engineering 2021年第1期14卷 38-49页

作者： Haibo chen Yubin Lan Bradley K Fritz w.clint hoffmann Shengbo Liu Experimental Basis and Practical Training center South China Agricultural UniversityGuangzhou 510642China National center for International collaboration Research on Precision Agricultural Aviation Pesticides Spraying Technology Guangzhou 510642China college of Electronic Engineering South China Agricultural UniversityGuangzhou 510642China USDA-ARS Aerial Application Technology Research Unit College StationTX 77845USA Prology consulting College StationTX 77845USA

with changing climate and farmland ecological conditions,pest outbreaks in agricultural landscapes are becoming more frequent,increasing the need for improved crop production tools and ***-based agricultural spraying is anticipated to be an important new technology for providing efficient and effective applications of crop protection *** paper reviews and summarizes the status of the current research and progress on UAV application technologies for plant protection,and it discusses the characteristics of atomization by unmanned aircraft application systems with a focus on spray applications of ***,the factors influencing the spraying performance including downwash airflow field and operating parameters are analyzed,and a number of key technologies for reducing drift and enhancing the application efficiency such as remote sensing,variable-rate technologies,and spray drift models are *** on the reviewed literature,future developments and the impacts of these UAV technologies are *** review may inspire the innovation of the combined use of big data analytics and UAV technology,precision agricultural spraying technology,drift reduction technology,swarm UAV cooperative technology,and other supporting technologies for UAV-based aerial spraying for scientific research in the world.

关键词： UAV plant protection spraying technology drift reduction pesticide efficacy spraying model big data analytics

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Development and prospect of unmanned aerial vehicle technologies for agricultural production management

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International Journal of Agricultural and Biological Engineering 2013年第3期6卷 1-10页

作者： Yanbo Huang Steven J.Thomson w.clint hoffmann Yubin Lan Bradley K.Fritz United States Department of Agriculture Agricultural Research ServiceCrop Production Systems Research UnitStonevilleMS 38776USA United States Department of Agriculture Agricultural Research ServiceAreawide Pest Management Research UnitCollege StationTX 77845USA

Unmanned aerial vehicles have been developed and applied to support agricultural production *** with piloted aircraft,an Unmanned Aerial Vehicle(UAV)can focus on small crop fields at lower flight altitudes than regular aircraft to perform site-specific farm management with higher *** can also“fill in the gap”in locations where fixed winged or rotary winged aircraft are not readily *** agriculture,UAVs have primarily been developed and used for remote sensing and application of crop production and protection *** of fertilizers and chemicals is frequently needed at specific times and locations for site-specific *** monitoring of crop plant health is often required at very high resolution for accurate site-specific management as *** paper presents an overview of research involving the development of UAV technology for agricultural production ***,systems and methods are examined and *** limitations of current UAVs for agricultural production management are discussed,as well as future needs and suggestions for development and application of the UAV technologies in agricultural production management.

关键词： unmanned aerial vehicle aircraft aerial application technology sensor remote sensing precision agriculture agricultural aviation

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