• Title/Summary/Keyword: Floating Body

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The Study for Correlation Characteristics on Radial Artery and Floating/sinking Pulse with BMI (BMI에 따른 요골동맥의 혈관특성과 부/침맥과의 상관관계 연구)

  • Lee, Yu-Jung;Lee, Jeon;Lee, Hae-Jung;Kim, Jong-Yeol
    • Korean Journal of Oriental Medicine
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    • v.14 no.3
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    • pp.121-126
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    • 2008
  • Pulse diagnosis refers to the process of diagnosing a patient by feeling an artery on the wrist based on the shape that the pulse take s while the hold-down pressure increase. The styloid process artery on the wrist is usually felt, and the pulse is taken on Chon, Gwan and Cheok using three fingers. This study is to examine the structural difference in the location of pulse diagnosis by measuring and analyzing blood diameter, blood depth, and blood flow velocity of the location of pulse diagnosis by using ultrasonic wave (VOLUSION730 PRO, GE Medical, U.S.A). This study also attempted to grasp whether the characteristics of blood vessels differ depending on Body Mass Index (BMI) and analyzed their correlation with Oriental medical pulse diagnosis. The male subjects without cardiovascular diseases were divided into the normal BMI group, the underweight group and the overweight group and 10 people of each group were measured, Blood depth, blood diameter and blood flow velocity at the location of pulse diagnosis (Chon, Gwan, Cheok) of the wrists of left and right hands were measured and the pulse wave was measured by using pulse diagnosis instrument (3-D Mac, DaeyoMedi, Korea).The results of this study showed that the characteristics of blood vessels differ depending on the degrees of obesity, and the characteristics of floating pulse and sinking pulse of Oriental medical pulses were related to the degrees of obesity. This shows that the characteristics of the blood vessels of subjects and BMI information are the major indicators for diagnosis and are the matters that must always be considered when developing the algorithm of pulse diagnosis.

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Experimental Study of Hydrodynamic Performance of Backward Bent Duct Buoy (BBDB) Floating Wave Energy Converter (부유식 진동수주형 파력발전기(BBDB)의 유체 동역학적 성능 실험 연구)

  • Kim, Sung-Jae;Kwon, Jinseong;Kim, Jun-Dong;Koo, Weoncheol;Shin, Sungwon;Kim, Kyuhan
    • Journal of Ocean Engineering and Technology
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    • v.26 no.6
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    • pp.53-58
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    • 2012
  • An experimental study on the hydrodynamic performance of a backward bent duct buoy (BBDB) was performed in a 2D wave tank. The BBDB is one of the promising oscillating water column (OWC) types of floating wave energy converters. Two different corner-shaped BBDBs (sharp-corner and round-corner) were used to measure the maximum chamber surface elevations and body motions for various incident wave conditions, and their hydrodynamic characteristics were compared. In order to investigate the effect of the pneumatic pressure inside the chamber, the heave and pitch angle interacted with elevations were compared for both open chamber and partially open chamber BBDBs. From the comparison study, the deviation in the chamber surface elevations between the two shapes of BBDBs was found to be significant near the resonance period, which may be explained by viscous energy loss. It was also found that the pneumatic pressure noticeably affected the chamber surface elevation and body motions.

Static and Dynamic Behavior at Low-Frequency Range of Floating Slab Track Discretely Supported by Rubber Mounts in Real-Scale Laboratory Test (고무 마운트로 이산 지지되는 플로팅 슬래브 궤도의 실모형 실내 실험에서의 정적 및 저주파 대역 동적 거동)

  • Hwang, Sung Ho;Jang, Seung Yup;Kim, Eun;Park, Jin Chul
    • Journal of the Korean Society for Railway
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    • v.15 no.5
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    • pp.485-497
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    • 2012
  • Recently, with increasing social interests on noise and vibration induced by railway traffic, the application of floating slab track that can efficiently reduce the railway vibration is increasing. In this study, to more accurately understand the dynamic behavior of the floating slab track, a laboratory mock-up test has been performed, and the static and dynamic behaviors at frequency range near the system resonance frequency were explored. Based on the test results, the design of the floating slab track and the structural analysis model used in the design have been verified. The analytic and test results demonstrate that the dominant frequency of the floating slab track occurs at the frequencies between vertical rigid body mode natural frequency and bending mode natural frequency, and the dominant deformation mode is close to the bending mode. This suggests that in the design of the floating slab track, the bending rigidity of the slab and the boundary conditions at slab joints and slab ends should be taken into consideration. Also, the analytic results by the two-dimensional finite element analysis model using Kelvin-Voigt model, such as static and dynamic deflections and force transmissibility, are found in good agreement with the test results, and thus the model used in this study has shown the reliability suitable to be utilized in the design of the floating slab track.

Parametric Study on Effect of Floating Breakwater for Offshore Photovoltaic System in Waves (해상태양광 구조물용 부유식 방파제의 파랑저감성능 평가)

  • Kim, Hyun-Sung;Kim, Byoung Wan;Lee, Kangsu
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.35 no.2
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    • pp.109-117
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    • 2022
  • There has been an increasing number of studies on photovoltaic energy generation system in an offshore site with the largest energy generation efficiency, as increasing the researches and developments of renewable energies for use of offshore space and resources to replace existing fossil fuels and resolve environmental challenges. For installation and operation of floating photovoltaic systems in an offshore site with harsher environmental conditions, a stiffness of structural members comprising the total system must be reinforced to inland water spaces as dams, reservoirs etc., which have relatively weak condition. However, there are various limitations for the reinforcement of structural stiffness of the system, including producible size, total mass of the system, economic efficiency, etc. Thus, in this study, a floating breakwater is considered for reducing wave loads on the system and minimizing the reinforcement of the structural members. Wave reduction performances of floating breakwaters are evaluated, considering size and distance to the system. The wave loads on the system are evaluated using the higher-order boundary element method (HOBEM), considering the multi-body effect of buoys. Stresses on structural members are assessed by coupled analyses using the finite element method (FEM), considering the wave loads and hydrodynamic characteristics. As the maximum stresses on each of the cases are reviewed and compared, the effect of floating breakwater for floating photovoltaic system is checked, and it is confirmed that the size of breakwater has a significant effect on structural responses of the system.

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.

Three-Dimensional Sheet Modeling Using Relative Coordinate (상대 좌표를 이용한 종이류 모델링 기법)

  • Cho Heui Je;Bae Dae Sung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.2 s.233
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    • pp.247-252
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    • 2005
  • This research presents a three-dimensional modeling technique for a flexible sheet. A relative coordinate formulation is used to represent the kinematics of the sheet. The three-dimensional flexible sheet is modeled by multi-rigid bodies interconnected by out-of-plane joints and plate force elements. A parent node is designated as a master body and is connected to the ground by a floating joint to cover the rigid motion of the flexible sheet in space. Since the in-plane deformation of a sheet such as a paper and a film is relatively small, compared to out-of-plane deformation, only the out-of-plane deformation is accounted for in this research. The recursive formulation has been adopted to solve the equations of motion efficiently. An example is presented to show the validity of the proposed method.

Analysis and Design of a Wave Energy Conversion Buoy

  • Oh, Jin-Seok;Bae, Soo-Young;Jung, Sung-Young
    • Journal of Navigation and Port Research
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    • v.32 no.9
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    • pp.705-709
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    • 2008
  • In the sea various methods have been conducted to capture wave energy which include the use of pendulums, pneumatic devices, etc. Floating devices, such as a cavity resonance device take advantages of both the water motion and the wave induced motions of the floating body itself. The wave energy converter is known commercially as the WAGB(Wave Activated Generator Buoy) and is used in some commercially available buoys to power navigation aids such as lights and horns. This wave energy converter consists of a circular flotation body which contains a vertical water column that has free communication with the sea. A theoretical analysis of this power generated by a pneumatic type wave energy converter is performed and the results obtained from the analysis are used for a real wave energy converter buoy. This paper is shown to have an optimum value for which maximum power is obtained at a given resonant wave period Also, the length of the internal water column corresponds to that of the water mass in the water column. If designed properly, wave energy converter can take advantage not only of the cavity resonance, but also qf the heaving motion of the buoy. Finally, simulation is performed with a LabVIEW program and the simulation results are applied to a wave energy simulator for modifying design data for a wave energy converter.

A Nonvolatile Refresh Scheme Adopted 1T-FeRAM for Alternative 1T-DRAM

  • Kang, Hee-Bok;Choi, Bok-Gil;Sung, Man-Young
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.8 no.1
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    • pp.98-103
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    • 2008
  • 1T1C DRAM has been facing technological and physical constraints that make more difficult their further scaling. Thus there are much industrial interests for alternative technologies that exploit new devices and concepts to go beyond the 1T1C DRAM technology, to allow better scaling, and to enlarge the memory performance. The technologies of DRAM cell are changing from 1T1C cell type to capacitor-less 1T-gain cell type for more scalable cell size. But floating body cell (FBC) of 1T-gain DRAM has weak retention properties than 1T1C DRAM. FET-type 1T-FeRAM is not adequate for long term nonvolatile applications, but could be a good alternative for the short term retention applications of DRAM. The proposed nonvolatile refresh scheme is based on utilizing the short nonvolatile retention properties of 1T-FeRAM in both after power-off and power-on operation condition.

Theoretical Analysis of Wave Energy Converter

  • Oh, Jin-Seok;Komatsu, Toshimitsu;Kim, Yun-Hyung
    • Journal of Advanced Marine Engineering and Technology
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    • v.32 no.1
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    • pp.169-174
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    • 2008
  • Floating devices, such as a cavity resonance device take advantage of both the water motion and the wave induced motions of the floating body itself. The wave energy converter is known commercially as the WAGB(Wave Activated Generator Buoy) and is used in some commercially available buoys to power navigation aids such as lights and horns. This wave energy converter consists of a circular floatation body which contains a vertical center pipe that has free communication with the sea. A theoretical analysis of this power generated by a pneumatic type wave energy converter is performed and the results obtained from the analysis are used for a real wave energy converter for buoy. This paper presents the analysis results and the design method for the WEC(Wave Energy Converter), and the associate results are application to the commercially available WEC for buoy. Maximum performance of WEC occurs at resonance with driving waves. The analysis of WEC is performed with LabVIEW program, and the design method of WEC for buoy is suggested in this paper.

Simulation and Experimental Methods for Media Transport System: Part I, Three-Dimensional Sheet Modeling Using Relative Coordinate

  • Cho, Heui-Je;Bae, Dea-Sung;Choi, Jin-Hwan;Lee, Soon-Geul;Rhim, Sung-Soo
    • Journal of Mechanical Science and Technology
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    • v.19 no.spc1
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    • pp.305-311
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    • 2005
  • This research presents a three-dimensional modeling technique for a flexible sheet. A relative coordinate formulation is used to represent the kinematics of the sheet. The three-dimensional flexible sheet is modeled by multi-rigid bodies interconnected by out-of-plane joints and plate force elements. A parent node is designated as a master body and is connected to the ground by a floating joint to cover the rigid motion of the flexible sheet in space. Since the in-plane deformation of a sheet such as a paper and a film is relatively small, compared to out-of-plane deformation, only the out-of-plane deformation is accounted for in this research. The recursive formulation has been adopted to solve the equations of motion efficiently. An example is presented to show the validity of the proposed method.