• Title/Summary/Keyword: Three Body Dynamics

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Numerical study of the effects of periodic body acceleration (PGZ) and bifurcation angle in the stenosed artery bifurcation

  • Ro, Kyoung-Chul;Ryou, Hong-Sun
    • Korea-Australia Rheology Journal
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    • v.21 no.3
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    • pp.175-183
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    • 2009
  • This article describes the numerical investigation of blood flow in the stenosed artery bifurcation with acceleration of the human body. Using the commercial software FLUENT, three-dimensional analyses were performed for six simulation cases with different body accelerations and bifurcation angles. The blood flow was considered to be pulsation flow, and the blood was considered to be a non-Newtonian fluid based on the Carreau viscosity model. In order to consider periodic body acceleration, a modified, time-dependent, gravitational-force term was used in the momentum equation. As a result, flow variables, such as flow rate and wall shear stress, increase with body acceleration and decrease with bifurcation angle. High values of body acceleration generate back flow during the diastolic period, which increases flow fluctuation and the oscillatory shear index at the stenosis.

Distribution Dynamics and Proposed Determinants: Exploring Morphological, Clinical Laboratory, and Lifestyle Factors in the Coexistence of Age-Related Skeletal Muscle Mass Loss and Obesity among Young Men: A Nationwide Cross-Sectional Study

  • Jongseok Hwang
    • Journal of the Korean Society of Physical Medicine
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    • v.19 no.1
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    • pp.31-41
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    • 2024
  • PURPOSE: This study examined the distribution dynamics and proposed determinants, including morphological measurements, clinical laboratory tests, and lifestyle factors among young Korean men aged 20 to 29 years with the coexistence of age-related loss of skeletal muscle mass and obesity (CALSMO). METHODS: Six hundred and sixty-six participants were divided into two groups based on their skeletal muscle mass index, with 12 individuals categorized in the CALSMO group and the remaining 654 in the normal group. The proposed determinants variables consisted of three main components: morphological measurements, clinical laboratory tests, and lifestyle factors. The morphological measurement variables were height, weight, body mass index, waist circumference, and skeletal muscle mass index. The clinical laboratory tests were fasting glucose, triglyceride, total cholesterol levels, and systolic and diastolic blood pressure. The lifestyle factors considered were alcohol consumption and tobacco use. Complex sampling analysis was performed for the evaluation. RESULTS: The distribution dynamics were determined to be 1.81(1.02-3.18) %. Morphological factors, such as height, weight, body mass index, waist circumference, and skeletal muscle mass index, showed significant differences (p < .05). The clinical laboratory test variables, specifically the fasting glucose, triglyceride, and total cholesterol levels, also exhibited significant differences (p < .05). The lifestyle factor, alcohol consumption, also showed a significance (p < .05). CONCLUSION: This study provides insights into the distribution dynamics. The proposed determinants in young Korean individuals with CALSMO are height, weight, body mass index, waist circumference, skeletal muscle mass index, fasting glucose, triglyceride, total cholesterol levels, and alcohol consumption.

Development of Korean Dummies Based on Anthropometric Data

  • Lee, Sang-Cheol;Son, Kwon;Kim, Seong-Jin;Jeong, Yun-Seok;Choi, Kyung-Hyun
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.181.1-181
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    • 2001
  • Human dummies are essential tools in the development of such sensible products as vehicles. Dummies are actively used not only in reach and view field tests, major ergonomic evaluations, but also in impact tests and perception evaluations. This study attempts to obtain possible correlations of human body segments from Korean anthropometric data. The investigation is focused on the description of human and dummy geometric and inertial properties. The modeling approach suggested is based on rigid body dynamics using fifteen individual body segments connected by joints. The segments are joined at locations representing the physical joints of the human body and have the mass of the body between body joints. For visualization, a three-dimension graphic technique is used ...

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Study on Optimum Curve Driving of Four-row Tracked Vehicle in Soft Ground using Multi-body Dynamics (다물체 동역학을 이용한 연약 지반 4열 궤도 차량의 최적 선회 주행 연구)

  • Oh, Jae-Won;Lee, Chang-Ho;Hong, Sup;Bae, Dae-Sung;Lim, Jun-Hyun;Kim, Hyung-Woo
    • Journal of Ocean Engineering and Technology
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    • v.28 no.2
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    • pp.167-176
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    • 2014
  • This paper proposes an optimum curve driving method for adeep-seabed mining robot(MineRo) in deep-sea soft ground. MineRo was designed as afour-row tracked vehicle. A study on the turning methods for the four-row tracked vehicle was conducted using three case by changing the velocity profile of each track. The configuration of the four-row tracked vehicle and soft ground equation are introduced, along with the dynamics analysis models of MineRo and soft ground, which were constructed using the commercial software DAFUL. Because the purpose of this study was to investigate a driving method on soft ground, the marine environment of the deep sea was not considered.

Dynamics of a Micro Three-axis Ring Gyroscope Considering Electrode Effects (전극 효과를 고려한 마이크로 3축 링 자이로스코프의 동역학)

  • 김창부;강태민
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.1
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    • pp.64-72
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    • 2004
  • In this paper. we analyse and present electro-mechanical dynamic characteristics of a micro-machined vibrating silicon ring gyroscope which can measure angular velocities about three orthogonal axes. The ring gyroscope has a ring connected to the gyroscope main body by support-ligaments which are arranged with cyclic symmetry. The natural modes of its vibration can be distinguished into the in-plane motion and the out-of-plane motion which are coupled by the gyro-effect due to the rotation of the gyroscope main body. The motions of the ring are electro-statically derived. sensed and balanced by electrodes. The equations of motion are formulated. The measuring method of angular velocities by force-to-rebalance is presented. The dynamic characteristics of a ring gyroscope are calculated and compared.

Dynamics of a Micro Three-Axis Ring Gyroscope (마이크로 3축 링 자이로스코프의 동역학)

  • Park, Sang-Hyun;Kim, Chang-Boo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11a
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    • pp.312.1-312
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    • 2002
  • In this paper, we analyse and present mechanical dynamic characteristics of a micro-machined vibrating silicon ring gyroscope which can measure rates of turn about three orthogonal axes. The ring gyroscope has a ring connected to the gyroscope main body by support-ligaments which are arranged with cyclic symmetry. The natural modes of its vibration can be distinguished into the in-plane motion and the out-of-plane motion which are coupled by the gyro-effect due to the rotation of the gyroscope main body. (omitted)

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Dynamics of a Micro Three-Axis Ring Gyroscope Considering Electrode Effects (전극 효과를 고려한 마이크로 3축 링 자이로스코프의 동역학)

  • 강태민;김창부
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.11a
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    • pp.970-976
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    • 2003
  • In this paper, we analyse and present electro-mechanical dynamic characteristics of a micro-machined vibrating silicon ring gyroscope which can measure angular velocities about three orthogonal axes. The ring gyroscope has a ring connected to the gyroscope main body by support-ligaments which are arranged with cyclic symmetry. The natural modes of its vibration can be distinguished into the in-plane motion and the out-of-plane motion which are coupled by the gyro-effect due to the notation of the gyroscope main body. The motions of the ring are electro-statically derived, sensed and balanced by electrodes. The equations of motion are formulated. The scheme of angular velocities sensing by force-to-rebalance method is presented. The dynamic characteristics of a ring gyroscope are calculated and compared.

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Dynamics of a Micro Three-axis Ring Gyroscope (마이크로 3축 링 자이로스코프의 동역학)

  • Kim, Chang-Boo;Choi, Sang-Hyun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.12
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    • pp.1001-1009
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    • 2002
  • In this paper, we analyse and present mechanical dynamic characteristics of a micro-machined vibrating silicon ring gyroscope which can measure angular velocities about three orthogonal axes. The ring gyroscope has a ring connected to the gyroscope main body by support-ligaments which are arranged with cyclic symmetry. The natural modes of its vibration can be distinguished into the in-plane motion and the out-of-plane motion which are coupled by the gyro-effect due to the rotation of the gyroscope main body. The equations of motion, the response to angular velocities, and the relationships between the natural modes of vibration are derived and compared with the previous studies for the design of a micro three-axis ring gyroscope.

Comparative Study on DAE Solution Methods for Effective Multi-Body Dynamics Analysis of Unmanned Military Robot Based on Subsystem Synthesis Method (무인 국방 로봇의 효과적인 다물체 동역학 해석을 위한 부분시스템 합성방법 기반 DAE 해석 기법 비교 연구)

  • Kim, Myoung Ho;Kim, Sung-Soo;Yun, Hong-Seon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.9
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    • pp.1069-1075
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    • 2013
  • An effective method is necessary for the real-time analysis of an unmanned military robot. To achieve highly efficient simulations, a subsystem synthesis method has been developed. The subsystem synthesis method separately generates equations of motion for the base body and for the subsystem. The equations of motion are expressed by DAE, which consist of differential equations and algebraic equations. To increase the accuracy and efficiency of solutions, DAE solvers such as the Direct, CS (Constraint Stabilization), and GCP (Generalized Coordinate Partitioning) method are employed. In this study, the subsystem synthesis method is applied for effective multi-body dynamics analysis of an unmanned military robot, and a comparative study of three different DAE solvers is carried out.

Effect of Chassis Flexibility on Ride Quality (샤시의 강성이 운전석 승차감에 미치는 영향 분석)

  • 김광석;유완석;이기호;김기태
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.2
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    • pp.127-136
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    • 1996
  • Dynamic analysis of a three-axle heavy truck is carried out with rigid body model and flexible body model. To see the effects of chassis flexibility, the chassis is modeled as flexible body. The mass matrix, stiffness matrix, and vibration normal modes of the chassis are obtained by a finite element analysis program, and four vibration normal modes are used in the flexible body model. The vehicle model consisting of a frame, a cab, suspensions, an engine, a deck, a seat, and tires, has total 77 degrees of freedom. The result shows that the peaked acceleration in the flexible model is lower than that of the rigid body model.

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