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miniaturized Twin-legged Robot with an Electromagnetic Oscillatory Actuator

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Journal of Bionic Engineering 2018年第1期15卷 106-113页

作者： Buhyun Shin Youngshik Kim Jamie Paik kyung-min lee Department of Mechanical Engineering Hanbat National University 125 Dongseodaero Yuseong-gu Daejeon 34158 Republic of Korea The Institute of Mechanical Engineering EPFL BM 4118 Station 17 1015-Lausanne Switzerland School of Mechanical Engineering Yeungnam University 280 Daehak-Ro Gyeongsan Gyeongbuk 38541 Republic of Korea

There have been many studies on the moving mechanism of micro robots, such as stick-slip, inchworm like motion, and impact drive. Novel actuators like lead zirconate titanate （PZT）, Shape Memory Alloy （SMA）, magnetostrictive materials, electromagnetic actuators, electoractive polymers, ultrasonic linear motors, and dielectric elastomers are utilized to realize the moving mechanism. The use of a conventional electromagnetic actuator is unfavorable, because of a few drawbacks, such as generation of stray magnetic fields, hard to miniaturize to the millimeter scale because of 3D integration and a scaling law, and power consumption to maintain a certain position. This research presents a micro robot that uses an electromagnetic actuator customized and developed for micro robot. The electromagnetic actuator is designed from a Brushless Direct Current （BLDC） motor to overcome the drawbacks mentioned above. The developed robot is composed of two electromagnetic actuators. The overall size of the robot is 20 mm × 11 mm× 9 mm （length × height × width） and the weight is 3 g. The developed robot is able to move bidirectionally with a maximum moving speed of 15.76 mm·s︿-1 （0.79 body-length per second）. The optimal conditions of an input signal are calculated theoretically and verified with experiments.

关键词： electromagnetic actuator oscillatory actuator bionic micro robot stick-slip brushless DC motor

Clawed miniature Inchworm Robot Driven by Electromagnetic Oscillatory Actuator

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Journal of Bionic Engineering 2015年第4期12卷 519-526页

作者： kyung-min lee Youngshik Kim Jamie K. Paik Buhyun Shin Korean Intellectual Property Office Gov. Complex-Daejeon Bldg. 4 189 Cheongsa-ro Se-gu Daejeon 302-701 Korea Department of Mechanical Engineering Hanbat National University 125 Dongseodaero Yuseong-gu Daejeon 305-719 Korea The Institute of Mechanical Engineering EPFL STIlGM UPPAIK BM 4118 (B~timent BM) Station 17 Switzerland

In this research we propose a novel inchworm robot, which is composed of an Electromagnetic Oscillatory Actuator （EOA） and claws. The EOA consists of a yoke, a magnet, and a coil. The overall robot size is 12.2 mm x 11 mm x 9 mm （length x height ~ width）. The locomotion of the robot is achieved by different amounts of slips when the robot stretches and contracts its front leg. To realize locomotion, the working conditions were calculated theoretically and the calculated input signal was applied to the robot. The performance of the inchworm robot was evaluated experimentally with varying input voltages and frequencies. A simple op-amps based driving circuit was used to provide a square-wave input. Travel speed, average distance per step of the robot, and moving distance of the leg and body at each step were measured. The maximum travel speed was 36 mm-s-1 at 30 Hz, which validates our simple locomotion strategy experimentally.

关键词： electromagnetic actuator micro mobile robot inchworm crawler locomotion

Overexpression of Arabidopsis YUCCA6 in Potato Results in High-Auxin Developmental Phenotypes and Enhanced Resistance to Water Deficit

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Molecular Plant 2013年第2期6卷 337-349页

作者： Jeong Im Kim Dongwon Baek Hyeong Cheol Park Hyun Jin Chun Dong-Ha Oh min kyung lee Joon-Yung Cha Woe-Yeon Kim min Chul Kim Woo Sik Chung Hans J. Bohner Sang Yeol lee Ray A. Bressan Shin-Woo lee Dae-Jin Yun Department of Biochemistry Purdue University West Lafayette IN 47907 USA Division of Applied Life Science (BK21 and WCU Program) Plant Molecular Biology and Biotechnology Research Center Gyeongsang National UniversityJinju 660-701 Republic of Korea Department of Plant Biology University of Illinois at Urbana-Champaign Urbana IL USA Department of Agronomy and Medicinal Plant Resources Gyeongnam National University of Science and Technology Jinju 660-758 Korea Faculty of Science King Abdulaziz University Jeddah 21589 KSA Department of Horticulture Purdue University West Lafayette IN 47907 USA

Indole-3-acetic acid （IAA）, a major plant auxin, is produced in both tryptophan-dependent and tryptophan-independent pathways. A major pathway in Arabidopsis thaliana generates IAA in two reactions from tryptophan. Step one converts tryptophan to indole-3-pyruvic acid （IPA） by tryptophan aminotransferases followed by a rate-limiting step converting IPA to IAA catalyzed by YUCCA proteins. We identified eight putative StYUC （Solanum tuberosum YUCCA） genes whose deduced amino acid sequences share 50%-70% identity with those of Arabidopsis YUCCA proteins. All include canonical, conserved YUCCA sequences： FATGY motif, FMO signature sequence, and FAD-binding and NADP-binding sequences. In addition, five genes were found with -50% amino acid sequence identity to Arabidopsis trypto-phan aminotransferases. Transgenic potato （Solanum tuberosum cv. Jowon） constitutively overexpressing Arabidopsis AtYUC6 displayed high-auxin phenotypes such as narrow downward-curled leaves, increased height, erect stature, and longevity. Transgenic potato plants overexpressing AtYUC6 showed enhanced drought tolerance based on reduced water loss. The phenotype was correlated with reduced levels of reactive oxygen species in leaves. The results suggest a func-tional YUCCA pathway of auxin biosynthesis in potato that may be exploited to alter plant responses to the environment.

关键词： Solanum tuberosum potato Arabidopsis thaliana yuc6-1D YUCCA, StYUCCA, StTAA, auxin, drought.

Densification simulation of compacted Al powders using multi-particle finite element method

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中国有色金属学会会刊：英文版 2009年第B9期19卷 68-75页

作者： kyung-Hun lee Jung-min lee Byung-min KIM School of Mechanical Engineering Pu san National University

The powder compaction simulations were performed to demonstrate deformation behavior of particles and estimate the effect of different punch speeds and particle diameters on the relative density of powder by a multi-particle finite element model(MPFEM). Individual particle discretized with a finite element mesh allows for a full description of the contact mechanics. In order to verify the reliability of compaction simulation by MPFEM, the compaction tests of porous aluminum with average particle size of 20 μm and 3 μm were performed at different ram speeds of 5, 15, 30 and 60 mm/min by MTS servo-hydraulic tester. The results show that the slow ram speed is of great advantage for powder densification in low compaction force due to sufficient particle rearrangement and compaction force increases with decrease in average particle size of aluminum.

关键词：粉末压实粉末粒子多孔铝有限元法模拟致密化平均粒径有限元模型

Effects of elastic-plastic properties of materials on residual indentation impressions in nano-indentation using sharp indenter

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中国有色金属学会会刊：英文版 2012年第S3期22卷 585-595页

作者： Jung-min lee Chan-Joo lee kyung-Hun lee Byung-min KIM Dongnam Regional Division Korea Institute of Industrial Technology Precision Manufacturing Systems Division Pusan National University School of Mechanical Engineering Pusan National University

One of the primary features of nano-indentation technique is that the contact area induced by an indenter is indirectly measured by a relationship between the penetration depth and the known geometry of the ***,this indirect measurement occasionally leads to inaccurate properties of the indented *** objective of this study is to investigate the effects of E/σr and the strain hardening exponents n of materials on the behaviors of pile-up and sink-in in nano-indentation and to predict n values of materials from the residual indentation *** relations between the residual indentation profile and n value of the indented material were identified by dimensional ***,they were numerically formulated using FE analysis of nano-indentation for 140 different combinations of elastic-plastic parameters such as E,σy and *** parameters of hrp/hm,herp/hm,Rr/hm and HO&P/Hreal were introduced as various dimensionless parameters to represent and quantify the residual indentation profile after *** were subsequently characterized as dimensionless functions using n and E/σr ***,the validity of these functions was verified through 3D FE analysis of nano-indentation for Al 6061-T6 and AISI 1010 materials.

关键词： nano-indentation pile-up sink-in strain hardening exponent FE simulation

FEA technique of hot plate forming process using cell-typed die with cooling device

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中国有色金属学会会刊：英文版 2012年第S3期22卷 831-837页

作者： Jung-min lee In-Kyu lee kyung-Hun lee Dae-Soon KIM Byung-min KIM Dongnam Regional Division Korea Institute of Industrial Technology School of Mechanical Engineering Pusan National University Industrial Technology Division Hyundai Heavy Industries

Hot plate forming using a cell-typed die is a process for forming a large thick plate with a spherical shape for the manufacture of a large spherical LNG ***-typed upper and lower dies made of a framework of steel plates fitted to make a grid pattern are used in this process,and an air-cooling device is separately installed inside the lower die.A finite element analysis (FEA) technique was developed,which included hot forming,air flow,cooling and thermal deformation analysis for the hot plate forming process using the cell-typed ***,the convective and interface heat transfer coefficients were used to reproduce analytically the effects of the cooling device in the hot plate forming analysis.A small-scale model test of the process was conducted to verify the FEA *** analysis results show that the curvature of the final plate agrees well with that of the designed experiment within a maximum relative error of 0.03% at the corner of the plate.

关键词： cell-typed die hot plate forming spherical LNG tank heat transfer coefficient

Stability of PAC(Psy-2A-Crt I) gene and agronomic traits in the F_(2:3) of IR36/PAC transgenic plants

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Journal of Integrative Agriculture 2015年第6期14卷 1163-1170页

作者： Hyun Suk lee Gihwan Yi kyung min Kim Division of Plant Biosciences School of Applied Biosciences College of Agriculture and Life Science Kyungpook National University Department of Farm Management College of Agriculture and Life Science Kyungpook National University

This study was carried out to evaluate the expression of yellow endosperm color in the progeny of Psy-2A-Crt I（β-carotene gene, PAC） transgenic plants crossed with IR36. The selected 25 lines of F2 progeny exhibited stable expression of yellow endosperm color and high agronomic characteristics. IR36 and PAC transgenic plant of the grain length, width and ratio showed the same tendency of normal distribution. For progeny selection, colorimeters were as employed to distinguish differing visible colors. Correlation analysis was conducted to investigate the relationship between b＊ value and the expression of specific genes. b＊ value was associated with the relative expression of the PAC-Rev and MAR product by real-time PCR and t-test revealed significant difference. Based on this study, correlation between colorimetric values and real-time PCR was effective to detect gene expression. Yellow endosperm progenies represent a new genetic pool that might be useful to increase the genetic diversity of yellow endosperm rice.

关键词： transgenic agronomic crossed yellow breeding panicle length distinguish phenotype Correlation

Is effect of transcranial direct current stimulation on visuomotor coordination dependent on task difficulty?

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Neural Regeneration Research 2015年第3期10卷 463-466页

作者： Yong Hyun Kwon kyung Woo Kang Sung min Son Na kyung lee Department of Physical Therapy Yeungnam University College Department of Physical Therapy College of Rehabilitation ScienceDaegu University Department of Physical Therapy College of Health Science Cheongju University

Transcranial direct current stimulation （tDCS）, an emerging technique for non-invasive brain stimulation, is increasingly used to induce changes in cortical excitability and modulate motor behavior, especially for upper limbs. The purpose of this study was to investigate the effects of tDCS of the primary motor cortex on visuomotor coordination based on three levels of task difficulty in healthy subjects. Thirty-eight healthy participants underwent real tDCS or sham tDCS. Using a single-blind, sham-controlled crossover design, tDCS was applied to the primary motor cortex. For real tDCS conditions, tDCS intensity was 1 mA while stimulation was applied for 15 minutes. For the sham tDCS, electrodes were placed in the same position, but the stimu- lator was turned off after 5 seconds. Visuomotor tracking task, consisting of three levels （levels 1, 2, 3） of difficulty with higher level indicating greater difficulty, was performed before and after tDCS application. At level 2, real tDCS of the primary motor cortex improved the accurate index compared to the sham tDCS. However, at levels 1 and 3, the accurate index was not significantly increased after real tDCS compared to the sham tDCS. These findings suggest that tasks of mod- erate difficulty may improve visuomotor coordination in healthy subjects when tDCS is applied compared with easier or more difficult tasks.

关键词： neural regeneration transcranial direct current stimulation visuomotor coordination task difficulty primary motor area motor learning neural regeneration

Does hemispheric lateralization influence therapeutic effects of transcranial direct current stimulation?

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Neural Regeneration Research 2016年第1期11卷 126-129页

作者： Yong Hyun Kwon kyung Woo Kang Na kyung lee Sung min Son Department of Physical Therapy Yeungnam University College Department of Physical Therapy College of Rehabilitation Science Daegu University Department of Physical Therapy College of Health Science Cheongju University

This study investigated the effect of transcranial direct current stimulation（t DCS） polarity depending on lateralized function of task property in normal individuals performing visuomotor and simple repetitive tasks. Thirty healthy participants with no neurological disorders were recruited to participate in this study. Participants were randomly allocated into active or control condition. For the active condition, t DCS intensity was 2 m A with stimulation applied for 15 minutes to the right hemisphere（t DCS condition）. For the sham control, electrodes were placed in the same position, but the stimulator was turned off after 30 seconds（sham condition）. The tapping and tracking task tests were performed before and after for both conditions. Univariate analysis revealed significant difference only in the tracking task. For direct comparison of both tasks within each group, the tracking task had significantly higher Z score than the tapping task in the t DCS group（P 〈 0.05）. Thus, our study indicates that stimulation of the right hemisphere using t DCS can effectively improve visuomotor（tracking） task over simple repetitive（tapping） task.

关键词： nerve regeneration transcranial direct current stimulation visuomotor task tracking task task property hemispheric lateralization neural regeneration