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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

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

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

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

Development of a PWM Precision Spraying Controller for Unmanned Aerial Vehicles

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Journal of Bionic Engineering 2010年第3期7卷 276-283页

作者： W.Clint hoffmann Brad Fritz USDA-ARS College Station

This paper presents a new Pulse Width Modulation (PWM) controller for Unmanned Aerial Vehicle (UAV) precisionsprayer for agriculture using a TL494 fixed-frequency pulse width modulator together with a data acquisition board and developedsoftware. An UAV can be remotely controlled or flown autonomously by pre-programmed flight plans. The PWMcontroller was implemented through the guidance system on the UAV with control commands sent between the UAV helicopterand the ground control station via a wireless telemetry system. The PWM controller was tested and validated using LabVIEW8.2. Several analyses were performed in a laboratory to test different control signals. The results show that the PWM controllerhas promise as a higher precision technique for spray applications, which will improve efficiency of pesticide application,especially in crop production areas.

关键词： PWM controller TL494 precision spraying UAV

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

Blockchain Use Cases Revisited:Micro-Lending Solutions for Retail Banking and Financial Inclusion

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Journal of Systems Science and Information 2021年第1期9卷 1-15页

作者： Christian Hugo hoffmann Universily of Zurich Deputy Director of the Suwiss Fin Tech Innovation LabHead of Artificial Intelligence(AD)Plaltenstrasse 148032 ZurichSwilzerland

While blockchain technology is commonly considered potentially disruptive in various regards,there is a lack of understanding where and how blockchain technology is effectively applicable and where it has remarkable practical effects~([1]).Against this background,we present and discuss a case study at length on the impact of this technology in the concrete setting of small short-term loans in retail *** propose to banks a robust and scalable blockchain technology with proof of stake and limited energy consumption used to streamline their processes,resulting in lower transaction and administration *** is made possible by smart ***,we facilitate small scale lending at high frequencies and short-term duration as well as an easier and more efficient way to connect small borrowers and lenders.

关键词： design science blockchain smart contracts asymmetric information fintech microfinance

The lacustrine sedimentary records of coal-burning atmospheric pollution

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Science China Earth Sciences 2005年第10期48卷 1740-1746页

作者： E. Appel V. hoffmann Institut für Geowissenschaften Universitt Tübingen 72076 Tübingen GermanyInstitut für Geowissenschaften Universitt Tübingen 72076 Tübingen Germany

Based on the studies on diatom, ostracods and magnetism on a core acquired from lacustrine sediments, as well as correlation analysis between concentration of acid diatom and the instantaneous lowest pH value, the processes of environment evolution in Lake Yangzonghai were reconstructed. The lacustrine environment was favorable in the 1950s, and began to be polluted by a coal-burning power plant since 1960. During 1965―1980, the instantaneous lowest pH value of lake water decreased to 5―6 when heavily polluted. There was a decrease trend in the pollution from 1983 to 1999, but coal-burning atmospheric pollution was still a main problem for environmental retrieving. As acid precipitated, acid-tolerant species overspread, and shellfish disappeared, as well as ferromagnetic particulates dissolved because of the consequent change of pH-Eh values in the interface of water and soil, which results in the change of environmental proxies versus depth. Thus, the environmental evolution of Lake Yangzonghai is reconstructed in this paper based on the inferences mentioned above.

关键词： atmospheric pollution, proxies, environmental reconstruction, lacustrine sediment, Lake Yangzonghai.

Reducing SARS-CoV-2 pathological protein activity with small molecules

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Journal of Pharmaceutical Analysis 2021年第4期11卷 383-397页

作者： Donata Pluskota-Karwatka Marcin hoffmann Jan Barciszewski Faculty of Chemistry Adam Mickiewicz University in Poznań61-614PoznańPoland NanoBiomedical Center of the Adam Mickiewicz University 61-614PoznańPoland Institute of Bioorganic Chemistry of the Polish Academy of Sciences 61-704 PoznańPoland

Coronaviruses are dangerous human and animal *** newly identified coronavirus SARS-CoV-2 is the causative agent of COVID-19 outbreak,which is a real threat to human health and *** world has been struggling with this epidemic for about a year,yet there are still no targeted drugs and effective treatments are very *** to the long process of developing new drugs,reposition of existing ones is one of the best ways to deal with an epidemic of emergency infectious *** the existing drugs,there are candidates potentially able to inhibit the SARS-CoV-2 replication,and thus inhibit the infection of the *** therapeutics target several proteins,and many diseases share molecular *** such cases,the use of existing pharmaceuticals for more than one purpose can reduce the time needed to design new *** aim of this review was to analyze the key targets of viral infection and potential drugs acting on them,as well as to discuss various strategies and therapeutic approaches,including the possible use of natural *** highlighted the approach based on increasing the involvement of human deaminases,particularly APOBEC deaminases in editing of SARS-CoV-2 *** can reduce the cytosine content in the viral genome,leading to the loss of its *** also indicated the nucleic acid technologies as potential approaches for COVID-19 *** numerous promising natural products,we pointed out curcumin and cannabidiol as good candidates for being antiSARS-CoV-2 agents.

关键词： SARS-CoV-2 COVID-19 Deamination APOBEC Therapeutic nucleotides Natural products Curcumin