• Title/Summary/Keyword: vertical motion

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Comparative Study of Vertical Axillary Muscle Sparing and Posterolateral Thoracotomy (수직액와 근육보존 개흉술과 후측방개흉술의 비교연구)

  • Seong, Suk-Hwan;Won, Tae-Hui
    • Journal of Chest Surgery
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    • v.27 no.12
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    • pp.1008-1014
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    • 1994
  • Increased interest in alternative approach to thoractomy has developed because of the considerable morbidity associated with the standard posterolateral thoracotomy[ST]. Muscle sparing thoracotomy is appeared as excellent alternative because of less postoperative pain and morbidity than standard posterolateral one. Vertical axillary muscle sparing thoracotomy[VM] is the newly revised modified muscle sparing thoracotomy that overcomes the disadvantages of previous lateral muscle sparing thoracotomy such as seroma, cosmetic problems, and need of subcutaneous drains. We conducted a prospective study of 45 consecutive patients to compare postoperative pain, muscle strength of serratus anterior and latissimus dorsi, and range of motion of the shoulder girdle between ST and VM group. There were no difference in preoperative status, surgical procedure, morbidity, mortality and hospital stay between two groups. But there were significant less postoperative narcotics requirements, more preserved latissimus dorsi and serratus anterior muscle strength, nd larger range of motion of shoulder girdle [ especially flexion and internal rotation in VM group. The opening time was prolonged[p<0.01] but closing time was less in VM group [p<0.01]. The sum of opening and closing time was not different in two group. The length of incision line was shorter in VM group. The vertical skin incision was concealed by the upper arm.In conclusion vertical axillary muscle sparing thoracotomy is good alternative for various intrathoracic procedures with less postoperative pain, well preserved muscle strength,increased range of motion of the shoulder girdle and impressive cosmetic outcome.

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Study on Hydrodynamic Forces Acting on Tanker Hull with Consideration of Various Vertical Centers of Gravity in Drift Test (다양한 수직방향 무게중심을 고려한 사항 중 탱커 선체에 작용하는 유체력에 관한 연구)

  • Park, Taechul;Lee, Sungwook;Paik, Kwang-Jun;Moon, Sung-Ho
    • Journal of Ocean Engineering and Technology
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    • v.32 no.6
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    • pp.433-439
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    • 2018
  • An investigation was conducted to determine whether the changes in the maneuvering forces and moments acting on a hull could be affected by changing the vertical center of gravity (VCG) of a tanker. The changes in the hydrodynamic forces and moment acting on a hull according to the restraint conditions of motion were examined using CFD for cases where the VCG was located at the design draught (100% of draught), under the design draught (75% of draught), and at half of the design draught (50% of draught). The following motion restraint conditions were selected: (1) fixed restraints for everything; (2) heave, pitch, and roll free restraint; and (3) heave and pitch free restraints. It was found that restraint condition (2) had the best agreement with the model experiment results. In addition, it was found that the hydrodynamic forces and moment acting on the hull with restraint condition (2) could be greatly affected in the model tests and CFD calculations by the various configurations for the vertical center of gravity of the hull. Finally, it was concluded that the location of the vertical center of gravity of the hull could be an important factor when more accurate hydrodynamic maneuvering forces and moment are estimated.

A Study on the Nonlinear Motion of a Vertical Liquid Jet (수직하방 분사된 주의 비선형 거동에 관한 연구)

  • Seok, Ji-Gwon;Jeong, Hwan-Mun;Mun, Su-Yeon;Lee, Chung-Won
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.1
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    • pp.45-54
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    • 2002
  • The breakup phenomena of a vertical laminar jet issuing from capillary tubes in a quiescent ambient air are investigated using a forced vibration analysis of the surface wave. Using a linear approach to the transient jet velocity, an approximate solution fur the longitudinal motion of a vertical liquid jet is theoretically derived, thus performing an instability analysis by a vibration method. The damping term of this equation is nonlinear as it depends on dimensionless parameters, a Weber number, and an Ohnesorge number. The instability condition is determined based on whether the coefficient of the damping term is less than zero or not. Uniform drop formation is dependent on the vibration frequency fur the forced vibration case.

Comparison of Motion Sensor Systems for Gait Phase Detection (보행주기 검출용 모션 센서 시스템의 비교)

  • Park, Sun-Woo;Sohn, Ryang-Hee;Ryu, Ki-Hong;Kim, Young-Ho
    • Journal of the Korean Society for Precision Engineering
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    • v.27 no.2
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    • pp.145-152
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    • 2010
  • Gait phase detection is important for evaluating the recovery of gait ability in patients with paralysis, and for determining the stimulation timing in FES walking. In this study, three different motion sensors(tilt sensor, gyrosensor and accelerometer) were used to detect gait events(heel strike, HS; toe off, TO) and they were compared one another to determine the most applicable sensor for gait phase detection. Motion sensors were attached on the shank and heel of subjects. Gait phases determined by the characteristics of each sensor's signal were compared with those from FVA. Gait phase detections using three different motion sensors were valid, since they all have reliabilities more than 95%, when compared with FVA. HS and TO were determined by both FVA and motion sensor signals, and the accuracy of detecting HS and TO with motion sensors were assessed by the time differences between FVA and motion sensors. Results show of that the tilt sensor and the gyrosensor could detect gait phase more accurately in normal subjects. Vertical acceleration from the accelerometer could detect HS most accurately in hemiplegic patient group A. The gyrosensor could detect HS and TO most accurately in hemiplegic patient group A and B. Valid error ranges of HS and TO were determined by 3.9 % and 13.6 % in normal subjects, respectively. The detection of TO from all sensor signals was valid in both patient group A and B. However, the vertical acceleration detected HS validly in patient group A and the gyrosensor detected HS validly in patient group B. We could determine the most applicable motion sensors to detect gait phases in hemiplegic patients. However, since hemiplegic patients have much different gait patterns one another, further experimental studies using various simple motion sensors would be required to determine gait events in pathologic gaits.

Transient Buoyant Flows of a Stratified Fluid in a Vertical Channel

  • Park, Jun-Sang
    • Journal of Mechanical Science and Technology
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    • v.15 no.5
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    • pp.656-664
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    • 2001
  • A theoretical analysis is performed to describe the qualitative behavior of transient buoyant flows in a vertical channel. Consideration is given to the case of a fluid with a pre-existing stratification. The fluid motion is generated by giving impulsive anti-symmetric step-changes in temperature at the vertical left ad right sidewalls. The qualitative character of the flow is shown to be classified in the Rayleigh number (Ra)-Prandtl number ($sigma$) diagram. The transitory approach to the steady state can be monotonic or oscillatory, depending on ($sigma$-1)$^2$$pi$$^4$ 4$sigma$$R_a$. The prominent characteristics of time-dependent flow are discussed for large $R_a$. The profiles of temperature and velocity in the transient phase are depicted, which disclose distinctive time scales of motion. The transient process is shown to be sensitive to the Prandtl number. The detailed evolutions of flow and temperature fields are illustrated for large $R_a$.

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Analysis of Wave Loads of Ships with Advancing Speed in Regular Waves (규칙파중을 항행하는 선박의 파랑하중해석)

  • Lee, S.C.;Doh, D.H.;Goo, J.S.
    • Journal of Power System Engineering
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    • v.14 no.1
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    • pp.53-58
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    • 2010
  • A three-dimensional source distribution method is presented for the prediction of motions and vertical bending moments of ships travelling with forward speed in regular waves. Comparisons between theoretical and experimental results are shown for the motion responses and vertical bending moment of the S175 container ship model by Watanabe et al. The model ship was made of synthetic resins so as to simulate bending rigidity of a full scale ship. Numerical results are compared with experimental and numerical ones obtained in the literature. The results of comparison confirmed the validity of the proposed approach.

A Study on the Characteristics of Vertical Motions due to Changes of Submerged Shape in the Multi-Purpose Small Floating Body (다목적 소형 부유시설의 몰수부 형상변화에 따른 파랑중 수직운동 특성에 관한 연구)

  • OH, Yu-Na;KIM, Sang-Won;LEE, Gyoung-Woo;HAN, Seung-Jae;KIM, In-chul
    • Journal of Fisheries and Marine Sciences Education
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    • v.28 no.4
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    • pp.1024-1030
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    • 2016
  • This study gives the vertical motion analysis due to changes in Submerged shape of Multi-Purpose Small Floating Body in irregular waves using the commercial code(MAXSURF v.20) based on the Panel method. To verify the commercial code prior to the analysis, we guarantees the reliability of this paper's results using the commercial code by comparing with the results of experimental results on Catamaran. The anlysis conditions are ITTC wave spectrum, each encounter angle. Finally, we analyze the result of ship's response spectra for vertical motions.

The kinematics analysis of Discus throwing (원반던지기의 운동학적 분석)

  • Kim, Jong-In;Sun, Jae-Bok
    • Korean Journal of Applied Biomechanics
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    • v.13 no.2
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    • pp.29-47
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    • 2003
  • This study is to analyze the kinematic variables in release motion of discuss throwing. For the matter, 5 people from the national team and collegiate discuss throwing in the year 2001 were chosen as the subjects and two S-VHS video cameras set in 60frames/sec were used for recording their motions. Coordinated raw positions data through digitizing are smoothing by butter-worth 's low-pass filtering method at a cut off frequency 6.0Hz. and the direct linear transformation(DLT) method was employed to obtain 3-D position coordinates. The conclusions were as follows; 1. The better record players showed the shorter approach time in the last support phase. 2. In the displacement CG, the better record players showed the shorter displacement in medial-lateral direction, and the longer displacement in horizontal direction. In the motion, the COG showed longer displacement vertical direction. 3. The better record players showed the faster horizontal velocity than vertical velocity in the release. 4. The better record players showed to take the posture of vertical axis in the release.

Numerical study on motion characteristics of a free falling two-dimensional circular cylinder in a channel using an Immersed Boundary - Lattice Boltzmann Method (가상경계 격자 볼츠만 법을 이용한 채널 내 자유 낙하하는 2차원 원형 실린더의 운동 특성)

  • Jeong, Hae-Kwon;Ha, Man-Yeong;Yoon, Hyun-Sik;Kim, Sung-Jool
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.2489-2494
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    • 2008
  • The two-dimensional circular cylinder freely falling in a channel has been simulated by using Immersed boundary - lattice Boltzmann method in order to analyze the characteristics of motion originated by the interaction between the fluid and the solid. The wide range of the solid/fluid density ratio has been considered to identify the effect of the solid/fluid density ratio on the motion characteristics such as the falling time, the terminal velocity and the trajectory in the vertical and horizontal directions. In addition, the effect of the gap between the cylinder and the wall on the motion of two-dimensional circular cylinder freely falling has been revealed by taking into account a various range of the gap size. The Reynolds number in terms of the terminal velocity is diminished as the cylinder becomes close to the wall at the initial dropping position, since the repulsive force induced between the cylinder and wall constrains the vertical motion. Quantitative information about the flow variables such as the pressure coefficient and vorticity on the cylinders is highlighted.

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Total Dynamic Analysis of Deep-Seabed Integrated Mining System (심해저 광물자원 채광시스템의 통합거동 해석)

  • Kim, Hyung-Woo;Hong, Sup;Choi, Jong-Su;Yeu, Tae-Kyeong
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2006.11a
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    • pp.311-314
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    • 2006
  • This paper concerns about total dynamic analysis of integrated mining system. This system consists of vertical steel pipe, intermediate buffer station, flexible pipe and self-propelled miner. The self-propelled miner and buffer are assumed as rigid-body of 6-dof. Discrete models of vertical steel pipe and flexible pipe are adopted, which are obtained by means of lumped-parameter method. The motion of mining vessel is not considered. Instead, the motion of mining vessel is taken into account in form of various boundary conditions (e.g. forced excitation in slow motion and/or fast oscillation and so on). A terramechanics model of extremely soft cohesive soil is applied to the self-propelled miner. The hydrodynamic forces and moments are included in the dynamic models of vehicle and lifting pipe system. Hinged and fixed constraints are used to define the connections between sub-systems (vertical steel pipe, buffer, flexible pipe, miner). Equations of motion of the coupled model are derived with respect to the each local coordinates system. Four Euler parameters are used to express the orientations of the sub-systems. To solve the equations of motion of the total dynamic model, an incremental-iterative formulation is employed. Newmark-b method is used for time-domain integration. The total dynamic responses of integrated mining system are investigated.

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