• Title/Summary/Keyword: Multi-body System

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Dynamic Analysis of Floating Multi-Bodies Considering Crane Impact Loads (크레인 충격하중을 고려한 다중 부유체 운동해석)

  • Kim, Young-Bok;Kim, Yong-Yook
    • Journal of the Society of Naval Architects of Korea
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    • v.49 no.3
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    • pp.273-279
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    • 2012
  • The concept of the Mobile Harbor had been made recently as a kind of feeder vehicle to transfer a certain amount of container boxes (i.e. 250 TEU at a time) from main ocean container vessels over 5,000 TEU capacity to the container terminal on land. In a harbor a short distance apart from the land, the container loading/unloading operation has to be performed on the main deck of the Mobile Harbor using the container cranes in the state of side-by-side mooring with protection of fenders and robot arms in the gap. Even under the ocean condition of the sea state class 2 or 3, the operation has to be confirmed to be safely performed. In this situation, the floating bodies considering the multiple-body interaction effect also has to be examined whether they might behave safely or not. Especially, this study focuses on the dynamic behavior of the Mobile harbor when a container box is hanged on the crane and the impact load due to the slewing motion is imposed in a certain sea state. The motion response should be controlled within the motion level to assure the safe operation.

Development portable hair removal applies PET ($Pause^{10-90}$ and $Energy^{20-40}$ $Trigger^{1-7}$) function

  • Kim, Whi-Young
    • Journal of information and communication convergence engineering
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    • v.7 no.2
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    • pp.223-230
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    • 2009
  • For pulse trigger way and the energy injection rate according to PET ($Pause^{10-90}$ $Energy^{20-40}$ $Trigger^{1-7}$) function, indeed, human body condition, period of dormancy in this research about this back correctly adjustment possible and designed harmless micro carrying along style hair exclusion so that can design and manufacture and run special quality examination and Xenon flash lamp to crawl in human body. Because creating individual's skin model to do stable treatment by light transmission way by skin impedance and measure, must embody treatment special quality of most suitable that draw skin color, energy, wave length, approximately, transmission time, pulse delay etc. and want. Specially, saved standard of war treatment pulse modeling by skin impedance, and manufacture pulse modeling system of most suitable by skin subordinate, and embody suitable treatment pulse. Specially, embody as could do root of a hair exclusion being emitted in pulse form using multi wave length of 560nm, 590nm, 640nm, 755nm and embodied clinical data. If become research repletion furthermore little more, is seen that can approximate in commercialization.

Flow Analysis around Multi-Legged Underwater Robot "Crabster" to Evaluate Current Loads (다관절 해저로봇 'Crabster'에 작용하는 조류하중 산정 및 유동해석)

  • Park, Yeon-Seok;Kim, Wu-Joan;Jun, Bong-Huan
    • Journal of Ocean Engineering and Technology
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    • v.26 no.5
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    • pp.47-54
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    • 2012
  • In this study, numerical simulations were performed to evaluate the current loads acting on the multi-legged underwater robot "Crabster" with a variety of incident angles using the ANSYS-CFX package. The Reynolds-averaged Navier-Stokes equations were solved to simulate the fluid flow around Crabster to calculate the forces and moments induced by incoming currents with various angles. First, to assess the posture stability of the body, the forces and moments were calculated with various incident angles when the current acted in the vertical and horizontal directions. Next, two forms of legs (box and foil types) were evaluated to determine the hydrodynamic force variation. Finally, the current forces and moments acting on the Crabster body with the legs attached were estimated.

IMPROVEMENT OF RIDE AND HANDLING CHARACTERISTICS USING MULTI-OBJECTIVE OPTIMIZATION TECHNIQUES

  • KIM W. Y.;KIM D. K.
    • International Journal of Automotive Technology
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    • v.6 no.2
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    • pp.141-148
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    • 2005
  • In order to reduce the time and costs of improving the performance of vehicle suspensions, the techniques for optimizing damping and air spring characteristic were proposed. A full vehicle model for a bus is constructed with a car body, front and rear suspension linkages, air springs, dampers, tires, and a steering system. An air spring and a damper are modeled with nonlinear characteristics using experimental data and a curve fitting technique. The objective function for ride quality is WRMS (Weighted RMS) of the power spectral density of the vertical acceleration at the driver's seat, middle seat and rear seat. The objective function for handling performance is the RMS (Root Mean Squares) of the roll angle, roll rate, yaw rate, and lateral acceleration at the center of gravity of a body during a lane change. The design variables are determined by damping coefficients, damping exponents and curve fitting parameters of air spring characteristic curves. The Taguchi method is used in order to investigate sensitivity of design variables. Since ride and handling performances are mutually conflicting characteristics, the validity of the developed optimum design procedure is demonstrated by comparing the trends of ride and handling performance indices with respect to the ratio of weighting factors. The global criterion method is proposed to obtain the solution of multi-objective optimization problem.

Development of RecurDyn Module for Wind Turbine Analysis Applying BEM Theory (BEM 이론을 적용한 풍력발전기 해석용 RecurDyn 모듈 개발)

  • Lim, Dae Guen;Yoo, Wan Suk
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.2
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    • pp.115-120
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    • 2014
  • In this study, a module is developed for modeling and analyzing dynamic behavior of a wind turbine using RecurDyn, which is a commercial multi-body dynamics software developed by FunctionBay, Inc. The wind turbine consists of tower, nacelle, hub and blades. Tower and blades are regarded as flexible bodies for considering elastic effect using beam theory and spring force. In this paper, a constant speed wind was assumed and aerodynamic force is modeled using BEM theory. Dynamic analysis applying this aerodynamic force is carried out. To verify the validity of analysis results, these results are compared to those of GH-Bladed which is a commercial software for analyzing wind turbine system distributed by Garrad Hassan.

A Motion Analysis Study of Casers for Fish Boxes using Computer Simulation (컴퓨터 시뮬레이션을 이용한 어체 상자 제함기 동작 분석에 관한 연구)

  • Jung, Sung-Heon;Jun, Chul-Woong;Sohn, Jeong-Hyun
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.18 no.4
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    • pp.56-61
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    • 2019
  • In this country, mackerel landing, sorting, and packing are mostly performed manually, which is time consuming and labor intensive. An unloading automation system saves time and labor by automating the landing, sorting, and packing processes. Casers are devices for manufacturing packing boxes for fish used by unloading automation systems. The caser design in this study is for mackerel packing boxes. This caser makes a packing box based on a press using the caser's slide crank. When the caser makes a packing box, the manufacturing sequence is determined by the caser's production guide and assisting rod. The caser design in this study is simulated using a multi-body dynamics program. The simulation is used to analyze the caser and to visualize the box-making sequence.

A Study on a Dynamics Simulation Program Development for Floating Wind Turbines (부유식 풍력발전 시스템 동역학 해석 프로그램 개발 연구)

  • Rim, Chae-Whan;Song, Jin-Seop;Chung, Tae-Young;Moon, Seok-Jun;Go, Jin-Yong;Lee, Sung-Kyun;Bae, Dae-Sung;Bae, Dong-Hee
    • Journal of Wind Energy
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    • v.2 no.2
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    • pp.30-37
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    • 2011
  • A floating wind turbine dynamic simulation program, WindHydro, is newly developed taking into account wind inflow and incident wave. WindHydro consists of 5 modules, HDFloat for hydrodynamics, HDProp for hydrodynamic property calculation, HDMoor for mooring dynamics, AeroDyn for aerodynamics, DAFUL for multi-body dynamics with nonlinear elasticity, and interface program that connects each calculation module. A turbulent wind and regular wave load case is simulated for the 5-MW OC3-Hywind with a spar bouy platform and catenary mooring lines. The results are compared with the results of the FAST(developed by NREL). As a result, the overall system responses from WindHydro and FAST agree well although some differences in the generator responses are observed.

Implementation of Intelligence Electronic Acupuncture System based on WEB (WEB 기반 지능형 전자침 시스템 구현)

  • Park, Hyun-Sook;Hong, You-Sik
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.18 no.3
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    • pp.93-100
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    • 2018
  • The electronic acupuncture has the advantage of treating the patient with acupuncture by simultaneously analyzing the patient's physical condition and treatment condition. In this paper, it is proposed and developed an electronic acupuncture algorithm embedded in a multi pad. Especially, it is implemented the control algorithm using the optimal electronic dipstick calculation, sensing pad and DSP system for the patient's body condition. Moreover, in this paper, it is developed SW and HW prototypes that can receive personal information by patient and can receive multi-array type electronc needle guiding procedure based on WEB.

A Study on Multi-Vehicle Control of Electro Active Polymer Actuator based on Embedded System using Adaptive Fuzzy Controller (Adaptive Fuzzy 제어기를 이용한 Embedded 시스템 기반의 기능성 고분자 구동체의 이중제어에 관한 연구)

  • 김태형;김훈모
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.307-310
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    • 1997
  • In case of environment requiring safety such as human body and requiring flexible shape, a conventional mechanical actuator system does not satisfy requirement. Therefore, in order to solve this problem, a research of various smart material such as EAP (Electro Active Polymer), EAC (Electro Active Ceramic) and SMA (Shape Memory Alloy) is in progress. Recently, the highest preferring material among various smart material is EP (Electrostictive Polymer), because it has very fast response time, poerful force and large displacement. The previous researches have been studied properties of polymer and simple control, but present researches are studied a polymer actuator. An EP (Electostrictive Polymer) actuator has properties which change variably as shape and environmental condition. Therefore, in order to coincide with a user's purpose, it is important not only to decide a shape of actuator and mechanical design but also to investigate a efficient controller. In this paper, we constructed the control logic with an adaptive fuvy algorithm which depends on the physical properties of EP that has a dielectric constant depending on time.

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The Source Identification of Noise Using Characteristics of Transmission and the Reduction of Interior Noise for Changing the Input Factor (전달특성을 이용한 소음원 규명과 입력요소 변경에 의한 실내소음 저감)

  • Lee, You-Yub
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.17 no.12
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    • pp.1254-1261
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    • 2007
  • The structure has several types of noise and booming noise of a vehicle is usually caused by the vibration of the vehicle's body transmitted from the engine through the mounting system. Vector synthesis analysis is performed to predict the booming noise when the characteristic of the engine mounting system is changed., i.e., when magnitudes and phases of vibratory forces after the mounts are altered. To use this method effectively, the concept of Multi-dimensional-analysis and Experimental Design are introduced to identify the contributions of each vibration sources and transmission paths to interior noise. It was used 3inputs/1output system and found the magnitudes and phases of the forces for minimizing the noise. Finally, the synthesized interior booming noise level is predicted by the vector synthesis diagram. It is shown that the vector synthesis method can be used to obtain the optimum design characteristic of the mounting system to control the interior booming noise of a vehicle.