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Journal of Bionic Engineering 2016年第3期13卷 449-457页

作者： Hoang Vu Phan Hoon Cheol Park Artificial Muscle Research Center Konkuk University Seoul 143-701 South Korea Deptment of Advanced Technology Fusion Konkuk University Seoul 143-701 South Korea

We propose a control moment generator to control the attitude of an insect-like tailless Flapping-wing Micro Air Vehicle （FW-MAV）, where the flapping wings simultaneously produce the flight force and control moments. The generator tilts the stroke plane of each wing independently to direct the resultant aerodynamic force in the desired direction to ultimately generate pitch and yaw moments. A roll moment is produced by an additional mechanism that shifts the trailing edge, which changes the wing rotation angles of the two flapping wings and produces an asymmetric thrust. Images of the flapping wings are captured with a high-speed camera and clearly show that the FW-MAV can independently change the stroke planes of its two wings. The measured force and moment data prove that the control moment generator produces reasonable pitch and yaw moments by tilting the stroke plane and realizes a roll moment by shifting the position of the trailing edge at the wing root.

关键词： insect-like Flapping-wing Micro Air Vehicle (FW-MAV) control mechanism stroke plane beetle flight

Low-temperature crystalline lead-free piezoelectric thin films grown on 2D perovskite nanosheet for flexible electronic device applications

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Nano Research 2019年第10期12卷 2559-2567页

作者： Jong-Hyun Kim Sang Hyo Kweon Sahn Nahm KU-KIST Graduate School of Converging Science and Technology Korea University145 Anam-roSeongbuk-guSeoul 02841Republic of Korea Department of Material Science and Engineering Korea University145 Anam-roSeongbuk-guSeoul 02841Republic of Korea Department of Mechanical Engineering Kobe University1-1 Rokkodai-choNadaKobe 657-8501Japan

A monolayer of Sr2Nb3Oio(SNO)is deposited on the Pt/Ti/SiCWSi(Pt?Si)or Pt/Ti/polyimide(Pt-Pl)substrate by using the Langmuir-Blodgett method and employed as a seed-layer for the growth of a crystalline(Nai_xKx)NbO3(NKN)film at 350℃.The crystalline NKN film is grown along the[001]direction on the SNO/Pt-Si(or SNO/Pt-PI)*** to the presence of oxygen vacancies in the SNO seed-layer,the NKN film exhibits low ferroelectric properties and large leakage *** ameliorate these properties,the SNO/Pt-Si substrate is annealed in a 50 Torr oxygen atmosphere at 300℃,which removes the oxygen ***,the NKN film deposited on this substrate exhibits promising electrical properties,namely a dielectric constant of 278,dissipation factor of 1.7%,a piezoelectric 8nstant of 175 pm`V^-1,and a leakage current density of 6.47 x 10^-7 A cm^-2 at-0.2 MV *** electrical properties are obtained from the NKN film grown on the flexible SNO/Pt-PI substrate at 350°***,the NKN films grown on the SNO seed-layer at 350°C can be applied to electronic devices with flexible polymer substrates.

关键词： lead-free piezoelectric thin films low-temperature-deposition process two-dimensional(2D)nanosheet seed-layers polymer substrates

Velocity Profiles between Two Baffles in a Shell and Tube Heat Exchanger

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Journal of Thermal Science 2015年第4期24卷 356-363页

作者： Tae-Hyun Chang Chang-Hoan Lee Hae-Soo Lee Kwon-Soo Lee Senior Research Fellow of RESEAT Korea Institute of Science and Technology Information Korea Institute of Science and Technology Information Postdoctoral Research Fellow School of Mechanical Engineering of Kyungnam University International University of Korea

Heat exchangers are extensively utilized for waste heat recovery,oil refining,chemical processing,and steam *** this study,velocity profiles are measured using a 3D particle image velocimetry(PIV)system between two baffles in a shell and tube heat exchanger for parallel and counter *** PIV and computational fluid dynamics results show the occurrence of some strong vectors near the *** vectors are assumed due to the clearance between the inner tubes and the front ***,the major parts of the vectors are moved out through the bottom opening of the rear baffle,and other vectors produce a large circle between the two *** simulations are conducted to investigate the effects of the baffle on the heat exchanger using the Fluent *** k-εturbulence model is employed to calculate the flows along the heat exchanger.

关键词： Baffle P1V Shell and tube heat exchanger Cut off ratio CFD

Discharge Characteristics of Large-Area High-Power RF Ion Source for Positive and Negative Neutral Beam Injectors

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Plasma Science and Technology 2016年第12期18卷 1220-1224页

作者： Doo-Hee CHANG Seung Ho JEONG Min PARK Tae-Seong KIM Bong-Ki JUNG Kwang Won LEE Sang Ryul IN Division of Nuclear Fusion Engineering & Technology Development Korea Atomic Energy Research Institute

A large-area high-power radio-frequency（RF） driven ion source was developed for positive and negative neutral beam injectors at the Korea Atomic Energy Research Institute（KAERI）. The RF ion source consists of a driver region, including a helical antenna and a discharge chamber, and an expansion region. RF power can be transferred at up to 10 kW with a fixed frequency of 2 MHz through an optimized RF matching system. An actively water-cooled Faraday shield is located inside the driver region of the ion source for the stable and steady-state operations of high-power RF discharge. Plasma ignition of the ion source is initiated by the injection of argongas without a starter-filament heating, and the argon-gas is then slowly exchanged by the injection of hydrogen-gas to produce pure hydrogen plasmas. The uniformities of the plasma parameter,such as a plasma density and an electron temperature, are measured at the lowest area of the driver region using two RF-compensated electrostatic probes along the direction of the shortand long-dimensions of the driver region. The plasma parameters will be compared with those obtained at the lowest area of the expansion bucket to analyze the plasma expansion properties from the driver region to the expansion region.

关键词： neutral beam injector RF ion source plasma ignition power loading plasma parameters

A Novel Capability of Object Identification and Recognition Based on Integrated mWMM

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Computers, Materials & Continua 2023年第4期75卷 959-976页

作者： MZeeshan Sarwar Mohammed Hamad Alatiyyah Ahmad Jalal Mohammad Shorfuzzaman Nawal Alsufyani Jeongmin Park Department of Computer Science Air UniversityIslamabadPakistan Department of Computer Science College of Sciences and Humanities in AflajPrince Sattam Bin Abdulaziz UniversityAl-KharjSaudi Arabia Department of Computer Science College of Computers and Information TechnologyTaif UniversityTaif21944Saudi Arabia Department of Computer Engineering Tech University of Korea237 Sangidaehak-roSiheung-siGyeonggi-do15073Korea

In the last decade,there has been remarkable progress in the areas of object detection and recognition due to high-quality color images along with their depth maps provided by RGB-D *** enable artificially intelligent machines to easily detect and recognize objects and make real-time decisions according to the given *** cues can improve the quality of object detection and *** main purpose of this research study to find an optimized way of object detection and identification we propose techniques of object detection using two RGB-D *** proposed methodology extracts image normally from depth maps and then performs clustering using the Modified Watson Mixture Model(mWMM).mWMM is challenging to handle when the quality of the image is not ***,the proposed RGB-D-based system uses depth cues for segmentation with the help of *** it extracts multiple features from the segmented *** selected features are fed to the Artificial Neural Network(ANN)and Convolutional Neural Network(CNN)for detecting *** achieved 92.13%of mean accuracy over NYUv1 dataset and 90.00%of mean accuracy for the Redweb_v1 ***,their results are compared and the proposed model with CNN outperforms other state-of-the-art *** proposed architecture can be used in autonomous cars,traffic monitoring,and sports scenes.

关键词： Artificial intelligence convolutional neural network depth images interactive-object detection machine learning

Enhancement of photoresponsive electrical characteristics of multilayer MoS2 transistors using rubrene patches

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Nano Research 2015年第3期8卷 790-800页

作者： Eun Hei Cho Won Geun Song Cheol Joon Park Jeongyong Kim Sunkook Kim Jinsoo Joo Department of Physics Korea University Seou1136-713 R. O. Korea Department of Electronics and Radio Engineering Institute for Laser Engineering Kyung Hee University Yongin Gyeonggi-do 446-70 I R. O. Korea Center for Integrated Nanostructure Physics (CINAP) Institute for Basic Science (IBS) Department of Energy Science Sungkyunkwan University Suwon 440-746 R. O. Korea

Multilayer MoS2 is a promising active material for sensing, energy harvesting, and optoelectronic devices owing to its intriguing tunable electronic band structure. However, its optoelectronic applications have been limited due to its indirect band gap nature. In this study, we fabricated a new type of phototransistor using multilayer MoS2 crystal hybridized with p-type organic semiconducting rubrene patches. Owing to the outstanding photophysical properties of rubrene, the device characteristics such as charge mobility and photoresponsivity were considerably enhanced to an extent depending on the thickness of the rubrene patches. The enhanced photoresponsive conductance was analyzed in terms of the charge results of the nanoscale laser confocal time-resolved PL measurements. transfer doping effect, validated by the microscope photoluminescence （PL） and

关键词： MoS2 rubrene transistor photoresponsivity charge transfer

Intermittent, low-dose, antiandrogen monotherapy as an alternative therapeutic option for patients with positive surgical margins after radical prostatectomy

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Asian Journal of Andrology 2018年第3期20卷 270-275页

作者： Kyung Hwa Choi Seung Ryeol Lee Young Kwon Hong Dong Soo Park Department Urology CHA Bundang Medical Center CHA University Seongnam Korea.

The aim of the present study was to determine whether oncologic outcomes and adverse events associated with active on/off intermittent antiandrogen monotherapy （daily bicalutamide, 50 mg per day） are comparable with those of standard external beam radiation therapy （EBRT） or combined androgen blockade （CAB） therapy in prostate cancers with positive surgical margins after radical prostatectomy. Two hundred twenty-three patients with positive surgical margins post-radical prostatectomy who underwent active surveillance （AS, n = 32）, EBRT without hormone therapy （n = 55）, intermittent antiandrogen monotherapy without EBRT （IAAM, n= 50）, or CAB without EBRT （n = 86）, between 2007 and 2014, were reviewed retrospectively. Pathologic outcomes, biochemical recurrence rates, radiological disease progression, and adverse events were collected from medical records. Biochemical recurrence rates, biochemical recurrence-free survival rates, and radiological recurrence were not different between the groups （P = 0.225, 0.896, and 0.284, respectively）. Adverse event rates and severities were lower for IAAM compared with EBRT or CAB （both P 〈 0.05）, but were comparable to those for AS （P = 0.591 and 0.990, respectively）. Grade ：〉3 adverse events were not reported in the IAAM or AS groups. Erectile dysfunction and loss of libido rates were lower in the IAAM group compared with the EBRT and CAB groups （P = 0.032）. Gastrointestinal complications were more frequently reported in the EBRT group （P = 0.008）. Active on/off IAAM treatment might be an appropriate treatment option for patients with positive surgical margins after radical prostatectomy. Furthermore, regarding oncologic outcomes, IAAM was comparable to standard EBRT but had a milder adverse event profile.

关键词： androgen receptor antagonists disease progression margins of excision prostatectomy prostatic neoplasms

Photocatalysts for degradation of dyes in industrial effluents:Opportunities and challenges

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Nano Research 2019年第5期12卷 955-972页

作者： Hassan Anwer Asad Mahmood Jechan Lee Ki-Hyun Kim Jae-Woo Park Alex C.K.Yip Department of Civil and Environmental Engineering Hanyang University222 Wangsimni-roSeoul 04763Republic of Korea Department of Environmental and Safety Engineering Ajou UniversitySuwon 16499Republic of Korea Department of Chemical and Process Engineering University of CanterburyChristchurch 8041New Zealand

Discharging dye contaminants into water is a major concern around the *** a variety of methods to treat dye-contaminated water,photocatalytic degradation has gained attention as a tool for treating the colored ***,we review the recent advancements in photocatalysis for dye degradation in industrial effluents by categorizing photocatalyst materials into three *** generation photocatalysts are composed of single-component materials (e.g.,TiO2,ZnO,and CdS),while second generation photocatalysts are composed of multiple components in a suspension (e.g.,WO3/NiWO4,BiOl/ZnTiOa,and C3N4/Ag3VO4).Photocatalysts immobilized on solid substrates are regarded as third generation materials (e.g.,FTO/WO3-ZnO,Steel/TiO2-WO3,and Glass/P-TiO2).Photocatalytic degradation mechanisms,factors affecting the dye degradation,and the lesser-debated uncertainties related to the photocatalysis are also discussed to offer better insights into environmental ***,quantum yields of different photocatalysts are calculated,and a performance evaluation method is proposed to compare photocatalyst systems for dye ***,we discuss the present limitations of photocatalytic dye degradation for field applications and the future of the technology.

关键词： photocatalyst dye wastewater degradation mechanism performance evaluation

Dynamic modeling and analysis of vortex filament motion using a novel curve-fitting method

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Chinese Journal of Aeronautics 2016年第1期29卷 53-65页

作者： Chang-Joo Kim Soo Hyung Park Sang Kyung Sung Sung-Nam Jung Department of Aerospace Information Engineering Konkuk UniversitySeoul 05029Republic of Korea

Applications of a novel curve-fitting technique are presented to efficiently predict the motion of the vortex filament, which is trailed from a rigid body such as wings and rotors. The gov- erning equations of the motion, when a Lagrangian approach with the present curve-fitting method is applied, can be transformed into an easily solvable form of the system of nonlinear ordinary dif- ferential equations. The applicability of Bezier curves, B-spline, and Lagrange interpolating polyno- mials is investigated. Local Lagrange interpolating polynomials with a shift operator are proposed as the best selection for applications, since it provides superior system characteristics with minimum computing time, compared to other methods. In addition, the Gauss quadrature formula with local refinement strategy has been developed for an accurate prediction of the induced velocity computed with the line integration of the Biot-Savart law. Rotary-wing problems including a vortex ring problem are analyzed to show the efficiency, accuracy, and flexibility in the applications of the pro- posed method.

关键词： Aerodynamics Biot-Savart law Curve-fitting method Free-vortex wake Rotary wing Vortex filament

Immediate muscle strengthening by an end-effector type gait robot with reduced real-time use of leg muscles: A case series and review of literature

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World Journal of Clinical Cases 2019年第19期7卷 2976-2985页

作者： Chang Ho Hwang Department of Physical Medicine and Rehabilitation Ulsan University Hospital University of Ulsan College of Medicine Department of Biomedical Engineering School of Electrical EngineeringUniversity of Ulsan

BACKGROUND De-afferentation or non-weight bearing induces rapid cortical and spinalα-motor neuron *** supposed that an end-effector type gait robot(EEGR)could provide patients with a training condition that was specific enough to activate rapid cortical/spinal neuroplasticity,leading to immediate muscle *** electromyographic and biomechanical comparisons were *** To compare the electromyographic activities of the thigh and shank muscles and isometric peak torque(PT)before and after walking training on a floor or in the end-effector gait *** Twelve outpatients without ambulatory dysfunction were *** of two interventions(5-min training on a floor at a comfortable pace or training in an EEGR with non-weight bearing on their feet and 100%guidance force at 2.1 km/h)were randomly *** PT,maximal ratio of torque development,amplitude of compound motor action potential(CMAP),and area under the curve(AUC)were evaluated before and 10 min after both *** The degree of PT improvement of the dominant knee flexors was larger in the EEGR than on the floor(9.6±22.4 Nm/BW,P<0.01).The EEGR-trained patients had greater PT improvement of the dominant knee extensors than those who trained on the floor(4.5±28.1 Nm/BW,P<0.01).However,all electromyographic activities of the thigh and shank muscles(peak CMAP,mean and peak AUC)were significantly lower for the use of the EEGR than walking on the *** Immediate strengthening of the knee flexors and extensors was induced after the 5-min EEGR training,despite reduced muscular use.

关键词： Robotics Rehabilitation Muscles Neuronal plasticity Gait Knee