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Stability case study of the ACROBOTeR underactuated service robot

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Theoretical & Applied Mechanics Letters 2012年第4期2卷 27-33页

作者： László L.kovács László Bencsik HAS-BMe Research Group on Dynamics of Machines and Vehicles Budapest H-1521Hungary Department of Applied Mechanics Budapest University of Technology and EconomicsBudapest H-1521Hungary

The dynamics of classical robotic systems are usually described by ordinary differential equations via selecting a minimum set of independent generalized coordinates. However, different parameterizations and the use of a nonminimum set of （dependent） generalized coordinates can be advantageous in such cases when the modeled device contains closed kinematic loops and/or it has a complex structure. On one hand, the use of dependent coordinates, like natural coordinates, leads to a different mathematical representation where the equations of motion are given in the form of differential algebraic equations. On the other hand, the control design of underactuated robots usually relies on partial feedback linearization based techniques which are exclusively developed for systems modeled by independent coordinates. In this paper we propose a different control algorithm formulated by using dependent coordinates. The applied computed torque controller is realized via introducing actuator constraints that complement the kinematic constraints which are used to describe the dynamics of the investigated service robotic system in relatively simple and compact form. The proposed controller is applied to the computed torque control of the planar model of the ACROBOTeR service robot. The stability analysis of the digitally controlled underactuated service robot is provided as a real parameter case study for selecting the optimal control gains.

关键词： stability underactuation natural coordinates control constraints

Hyperactive learning for data-driven interatomic potentials

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npj Computational Materials 2023年第1期9卷 599-612页

作者： Cas van der Oord Matthias Sachs Dávid Péter kovács Christoph Ortner Gábor Csányi University of Cambridge Cambridge CB21PZUK University of Birmingham Birmingham B152TTUK University of British Columbia VancouverBC V6T 1Z2Canada

Data-driven interatomic potentials have emerged as a powerful tool for approximating ab initio potential energy *** most time-consuming step in creating these interatomic potentials is typically the generation of a suitable training *** aid this process hyperactive learning(HAL),an accelerated active learning scheme,is presented as a method for rapid automated training database *** adds a biasing term to a physically motivated sampler(*** dynamics)driving atomic structures towards uncertainty in turn generating unseen or valuable training *** proposed HAL framework is used to develop atomic cluster expansion(ACe)interatomic potentials for the AlSi10 alloy and polyethylene glycol(PeG)polymer starting from roughly a dozen initial *** HAL generated ACe potentials are shown to be able to determine macroscopic properties,such as melting temperature and density,with close to experimental accuracy.

关键词： starting generating consuming

Monitoring of Heart Ischemia in Blood Serum

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Spectral Analysis Review 2016年第2期4卷 11-22页

作者： Vladimíra Tomečková Vladimír Komanický Mohammad Kakoush Kristína Krajčíková Gabriela Glinská Monika Široká Lýdia Pundová Tomáš Samuely Dominika Hložná Dmytro Lotnyk Department of Medical and Clinical Biochemistry Faculty of Medicine Pavol Jozef Safárik University in Kosice Slovak Republic Institute of Physics Faculty of Science Pavol Jozef Safárik University in Kosice Slovak Republic 1st Department of Internal Medicine Faculty of Medicine Pavol Jozef Safárik University in Kosice Slovak Republic

Our aim was to study the selected cases of the patients with ischemic heart disease and to analyze the structure of blood serum of patients in comparison with control serum of healthy subjects by methods: synchronous fluorescence fingerprint and atomic force microscopy that are still not used in clinical practice. Our results of fluorescence analysis showed that blood serum of all patients with ischemic heart disease decreased intensity of fluorescence in comparison with control blood serum. endogenous fluorescence of synchronous fluorescence fingerprint of blood serum of patients with unstable angina pectoris state after non ST elevation myocardial infarction;angina pectoris and arterial hypertension 3 was similar, but atomic force microscopy revealed differences in the structure of blood serum of patients with the angina pectoris. Blood serum of patients with angina pectoris exhibited disappearance of fluorescence peak with maximum fluorescence and showed lower fluorescence intensity than control blood serum and blood serum of patients with arterial hypertension 2. Profiles of synchronous fluorescence fingerprint of blood serum of patients with arterial hypertension stage 2 showed formation of the new fluorescent peak with maximum fluorescence, similar shape of synchronous fluorescence fingerprint and higher fluorescence intensity than blood serum of healthy subjects. Blood serum sensitively revealed changes in the body by using untraditional novel techniques which enable the analysis of the mixture of blood serum and might be a new possibility in study of heart ischemia diseases.

关键词： Blood Serum fluorescence Analysis Atomic force Microscopy Ischemic Heart Disease

Antioxidant efficiency of lycopene on oxidative stress-induced damage in bovine spermatozoa

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Journal of Animal Science and Biotechnology 2017年第1期8卷 67-79页

作者： eva Tvrdá Anton kovácik eva Tusimová Dusan Paál Alica Mackovich Jakhongir Alimov Norbert Lukác Department of Animal Physiology Faculty of Biotechnology and Food Sciences Slovak University of Agriculture in Nitra Tr. A. Hlinku 2 Nitra 94976 Slovakia AgroBioTech Research Centre Slovak University of Agriculture in Nitra Tr. A. Hlinku 2 Nitra 94976 Slovakia Department of Botany and Genetics Faculty of Natural Sciences Constantine the Philosopher University in Nitra Nabbrezie mladeze 91 Nitra 94974 Slovakia Department of General Biology Faculty of Natural Sciences Gulistan State University 4th Microrayon Guliston 120100 Syrdarya Uzbekistan.

background： Lycopene（LYC） is a natural carotenoid with powerful reactive oxygen species（ROS） scavenging activities. The aim of this study was to investigate if lycopene has the ability to reverse ROS-mediated alterations to the motility, viability and intracellular antioxidant profile of bovine spermatozoa subjected to ferrous ascorbate（fe AA）. Spermatozoa were washed out of fresh bovine semen, suspended in 2.9 % sodium citrate and subjected to LYC treatment（0.25, 0.5, 1 or 2 mmol/L） in the presence or absence of fe AA（150 μmol/L fe SO4 and 750 μmol/L ascorbic acid） during a 6 h in vitro culture. Spermatozoa motion characteristics were assessed using the Sperm Vision？computer-aided sperm analysis（CASA） system. Cell viability was examined with the metabolic activity（MTT） assay,ROS generation was quantified via luminometry and the nitroblue-tetrazolium（NBT） test was applied to quantify the intracellular superoxide formation. Cell lysates were prepared at the end of the in vitro culture to investigate the intracellular activity of superoxide dismutase（SOD）, catalase（CAT）, glutathione peroxidase（GPx） as well as the concentrations of glutathione（GSH） and malondialdehyde（MDA）.Results： feA A treatment led to a reduced spermatozoa motility（P 〈 0.001）, viability（P 〈 0.001） and a decline of the antioxidant capacity of spermatozoa（P 〈 0.001） but increased the ROS generation（P 〈 0.001）, superoxide production（P 〈 0.001） and lipid peroxidation（P 〈 0.001）. LYC administration resulted in a preservation of the spermatozoa motion parameters（P 〈 0.001）, mitochondrial activity（P 〈 0.001） and antioxidant characteristics（P 〈 0.001 with respect to SOD;P 〈 0.01 in relation to CAT; P 〈 0.05 as for GPx and GSH） with a concentration range of 1 and 2 mmol/L LYC revealed to be the most ***： Our results suggest that LYC exhibits significant ROS-scavenging and antioxidant properties which may prevent spermatozoa alterations caused by oxidative stress, and preserve the functional

关键词： Antioxidants Bulls ferrous ascorbate Lycopene Oxidative stress Spermatozoa

网络营销对斯洛伐克在线消费者行为的影响研究

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网络营销对斯洛伐克在线消费者行为的影响研究

作者： Bc. Katarína Sláde(?)ková（琳娜) 天津大学

学位级别：硕士

本硕士论文主要研究在线营销的影响及其对斯洛伐克消费者行为的影响。由于日益全球化和流行病,在线营销和在线购物的使用一直在迅速增长。这个话题引起了我的注意,并吸引我去调查什么样的内部和外部因素,以及这些因素在多大程度上影响... 详细信息

本硕士论文主要研究在线营销的影响及其对斯洛伐克消费者行为的影响。由于日益全球化和流行病,在线营销和在线购物的使用一直在迅速增长。这个话题引起了我的注意,并吸引我去调查什么样的内部和外部因素,以及这些因素在多大程度上影响了斯洛伐克的消费者行为。此外,它继续研究最有效的内容营销类型以及这些类型在多大程度上影响和影响斯洛伐克消费者的行为。此外,我的目标是发现斯洛伐克消费者使用哪些类型的社交媒体,以及哪些特定的社交媒体对他们的行为影响最大。本论文采用的主要方法是基于问卷调查的统计分析,包含封闭式问题和十个量表,分发给斯洛伐克在线消费者,共有三百五十个有效回答可供访问。为了更深入、准确地分析斯洛伐克消费者行为数据,采用了以下统计方法:卡方检验、皮尔逊系数、尤尔系数和弗里德曼检验。主要的发现如下:客户的信念和态度、动机和价格等因素会影响和影响斯洛伐克消费者;对消费者更具吸引力的特定内容营销类型主要包括视频内容、网络研讨会和网页;结果表明斯洛伐克公民使用最多的媒体工具是脸书和照片墙社交媒体网站,这些媒介上的广告策略可以影响消费者的行为。这项研究可为斯洛伐克众多公司的营销提供有用的见解,这些公司常使用互联网作为促销基地或拥有在线商店。该研究还为该国公司的营销指出了另一种可能的解决方案,即如何策略性地规划在线营销,以及如何、何时以及将哪些类型的内容营销和社交媒体平台实施到可能增加其市场价值和商业风险的营销战略中。

关键词：网络营销斯洛伐克数字营销内容营销社交媒体

Morphological characteristics of blood cells in monitor lizards:is erythrocyte size linked to actual body size?

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Integrative Zoology 2013年第1期8卷 39-45页

作者： Petra fRÝDLOVÁ Jan HNÍZDO Lenka CHYLÍkovÁ OlgaŠIMkovÁ Veronika CIKÁNOVÁ Petr VeLeNSKÝ Daniel fRYNTA Department of Zoology Charles University in PraguePragueCzech Republic Animal Clinic PragueCzech Republic Prague Zoo PragueCzech Republic

Blood cell morphology and count are not uniform across ***,between-species comparisons revealed that the size of red blood cells is associated with body size in some lizard taxa,and this finding was interpreted in the context of the metabolic *** the present study,we examined the numbers and the size of blood cells in 2 species of monitor lizards,the mangrove-dwelling monitor(Varanus indicus)and the savannah monitor(***),and we compared these traits in individuals of different body *** results revealed that during the course of ontogeny,the size of red blood cells increases with body *** the mass-specific metabolic rate decreases with body size and the cell volume-to-surface ratio decreases with the cell size,changes in the erythrocyte size might be the result of oxygen transport adjustment.

关键词： blood parameters body size erythrocyte size metabolic theory Varanidae

efficiency of local minima and GLM techniques in sinkhole extraction from a LiDAR-based terrain model

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International Journal of Digital earth 2019年第9期12卷 1067-1082页

作者： Péter enyedi Melinda Pap Zoltán kovács László Takács-Szilágyi Szilárd Szabó a Department of Physical Geography and Geoinformatics University of DebrecenDebrecenHungary Internet of Things Research Institute Eszterházy Károly University of Applied SciencesEgerHungary

The aim of this paper was to study reliable automated delineationpossibilities of karst sinkholes using a LiDAR-based digital terrain model(DTM) with pixel-based classifications. We applied two approaches toextract sinkholes: (1) general linear modeling (GLM) with morphometricindices derived from DTM;(2) and a local minima-based delineationusing only LiDAR DTM as the input layer. The outcome of the localminima was significantly different from the reference ones but found allthe sinkholes without previous knowledge of the area. The GLM-basedoutcome did not differ statistically from the reference. Results showedthat these approaches were efficient in detecting sinkholes based onLIDAR derivatives, and can be used for risk assessment and hazardpreparedness in karst areas: GLM had an overall accuracy of 89.5% andlocal minima had an accuracy of 92.3%;both methods identifiedsinkholes but also had commission errors, identifying depressions assinkholes.

关键词： Karst mapping sinkhole identification general linear model statistical evaluation sink fill

Contribution of Good Agricultural Practices to Soil Biodiversity

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Open Journal of ecology 2021年第1期11卷 75-85页

作者： Beata Houšková Rastislav Bušo Jarmila Makovníková national Agricultural and food Centre/Soil Science and Conservation Research Institute Bratislava Slovakia national Agricultural and food Centre/VÚ RV Pie&#353 ť any Slovakia national Agricultural and food Centre/Soil Science and Conservation Research Institute Banská Bystrica Slovakia

At present time when climate change has negative effect on soil moisture and can decrease significantly the productivity, good agricultural practises have a high importance via their direct influence on soil properties, regimes and biodiversity. Objectives of this study have been focused on the assessment of good agricultural practises in different soil cultivation types: conventional, minimum till, mulch, no-till and organic farming. Method used was based on two case study areas where organic and/or minimal farming systems have been applied. As a control, we chose soil with traditional cultivation. In organic farm, we evaluated earthworms;their amount and status and in farm with different types of cultivation we evaluated the microbial activity to assess the biodiversity conditions. basic soil properties and soil structure have been set to be able to assess the influence of good agricultural practises on soil environment. Our study shows positive effect of these practises on soil moisture content, biodiversity and soil structure stability. These findings can be used for further studies determining the ways of soil cultivation in harmony with nature—in sustainable way.

关键词： Good Agricultural Practices Soil Biodiversity earthworms Microorganisms Soil enzymes Organic farm Soil Moisture

Positive Solution for a Singular fourth-Order Differential System

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Journal of Applied Mathematics and Physics 2021年第9期9卷 2244-2257页

作者： B. kovács Institute of Mathematics University of Miskolc Miskolc Hungary

In this paper, we investigate the existence of positive solutions for the singular fourth-order differential system u(4) = φu + f (t, u, u”, φ), 0 t φ” = μg (t, u, u”), 0 t u (0) = u (1) = u”(0) = u”(1) = 0, ... 详细信息

In this paper, we investigate the existence of positive solutions for the singular fourth-order differential system em>uem>(4) = em>φuem> + em>f em>(em>tem>, em>uem>, em>uem>”, em>φem>), 0 em>tem> em>φem>” = em>μgem> (em>tem>, em>uem>, em>uem>”), 0 em>tem> em>uem> (0) = em>uem> (1) = em>uem>”(0) = em>uem>”(1) = 0, em>φ em>(0) = em>φ em>(1) = 0;where em>μem> > 0 is a constant, and the nonlinear termsem> fem>, em>gem> may be singular with respect to both the time and space variables. The results obtained herein generalize and improve some known results including singular and non-singular cases.

关键词： Positive Solutions fixed Point Theorem Singular Solutions Bending of an elastic Beam Cone Boundary Value Problem existence Multiplicity