• Title/Summary/Keyword: Link Body

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Analyzing Materials Property using Optical Sensing Technique of Stabilizer Link for Automobile Parts (수송기계용 Stabilizer Link의 광센서를 이용한 부품성능평가)

  • Nam, K.W.;Woo, Y.M.;Oh, J.H.;Moon, C.K.
    • Journal of Power System Engineering
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    • v.14 no.6
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    • pp.47-53
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    • 2010
  • A stabilizer link connects the stabilizer bar to the lower arm of the suspension. When a vehicle is turning, lateral forces from the tire are transmitted through the stabilizer link into the stabilizer bar. The stabilizer bar will twist, thus adding rigidity to the vehicle body. In this study, the stabilizer link body was manufactured by using composite material with POM-GF25%. Therefore, the strength evaluation of stability link body with composite material carried out from tensile, wear and fatigue test. The tensile strength between the stability link body with composite material and the rod with knurling was the largest of four types of rod. In Analyzing materials property using optical sensing technique of stabilizer link for automobile parts, its has been identified the safety.

Estimation of anthropometric body dimensions and joint strengths of a worker performing manual materials handling tasks using a multivariate normal simulation model (다변량 정규분포 모의모형을 이용한 물자운반작업을 수행하는 작업자의 인체 치수 및 관절염력의 예측에 관한 연구)

  • 변승남
    • Journal of the Ergonomics Society of Korea
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    • v.12 no.2
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    • pp.63-83
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    • 1993
  • The primary objective of the research is to develop a mathematical method to incorporate the variability of anthropometric body dimensions and joint strengths of individuals in a biomechanical analysis. A multivariate normal simulation model estimated anthropometric body dimensions and joint strengths of the random link-person, based on the assumptions that the vari- ables of body dimensions and joint strengths are correlated and follow normal distributions. Statistical comparative analysis demonstrated that the random link-person represented a more realistic human-like form in an anthropometric sense than the proportional link-person whose body dimensions were estimated proportionally. Estimated joint strengths for the random link-person, however, did not match the measured joint strengths as closely as the estimated body dimensions. The random link-person will allow biomechanical analysis of manual materials handling tasks to be individualized with respect to the anthropometry and a static strength.

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Shape Finding of Unstable Link Structures (불안정(不安定) Link 구조물(構造物)의 형태해석(形態解析)에 관(關)한 연구(硏究))

  • Kim, Jae-Yeol
    • Journal of Korean Association for Spatial Structures
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    • v.3 no.2 s.8
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    • pp.101-107
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    • 2003
  • There exists a structural problem for link structures in the unstable state. The primary characteristics of this problem are in the existence of rigid body displacements without strain, and in the possibility of the introduction of prestressing to change an unstable state into a stable state. When we make local linearized incremental equations in order to obtain knowledge about these unstable structures, the determinant of the coefficient matrices is zero, so that we face a numerically unstable situation. This is similar to the situation in the stability problem. To avoid such a difficult situation, in this paper a simple and straightforward method was presented by means of the generalized inverse for the numerical analysis of stability problem.

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A distributed relay selection algorithm for two-hop wireless body area networks

  • Kim, Seung-Ku;Joo, Yang-Ick
    • Journal of Advanced Marine Engineering and Technology
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    • v.41 no.2
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    • pp.156-162
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    • 2017
  • This paper investigates two-hop extension communication in wireless body area networks. Many previous studies have demonstrated that two-hop extended topology outperforms single-hop topology. Although many researchers have proposed using two-hop extension communication to improve link reliability, no one has considered using a relay selection algorithm or provided a suitable solution for wireless body area networks. The design goal of the proposed algorithm is selecting a proper relay node to retransmit failed packets distributively. The proposed algorithm configures the carrier sensing period to choose one relay node promptly without requiring additional interaction. We analyze the link conditions corresponding to various body postures and investigate which factors are proper to determine the carrier sensing period. The empirical results show that the proposed algorithm reduces the expected number of transmissions required to deliver a packet successfully.

Study of the Center of Gravity in the Human Body and each Segment (인체 중심과 분절 중심에 대한 연구)

  • Chung Hyung-Kuk;Bae Sung-Soo
    • The Journal of Korean Physical Therapy
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    • v.5 no.1
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    • pp.61-69
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    • 1993
  • It was performed to encourage for Physical Therapist to apply the theory of center of the human body and segments in clinical situations. This study was investigated literarily on center of the human body and segments. Methods which search for the center-2 types, that is, method using reaction broad and segmental method-was suggested. The center location difference of gravity in human body depends on individual character. Generally, the center location is in kent of 2nd sacrum, that is, at $55\%$ of height from foot. The center of each segment is on 'link'. In the first place we must how the weight of segment we can search for the center easily. Mean segment coater location of extremities is at $42.33\%$ from each proximal end, and mean center of head and trunk lies at $45\%$.

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Kinematic Analysis and Dynamic Balancing Technique in a Link-Motion Mechanism (링크모션 메커니즘의 기구학적 분석 및 다이나믹 발란싱 테크닉)

  • Suh, Jin-Sung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.11a
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    • pp.498-502
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    • 2004
  • In a link-motion mechanism, numerous links are interconnected and each link executes a constrained motion at a high speed. Due to the complicated constrained motions of the constituent links, dynamic unbalance forces and moments are generated and transmitted to the main frame. Therefore unwanted vibration is produced. This degrades productivity and precise work. Based on constrained multi-body dynamics, the kinematic analysis is carried out to enable design changes to be made. This will provide the fundamental information for significantly reducing dynamic unbalance forces and moments which are transmitted to the main frame. In this work, a link-motion punch press is selected as an example of a link-motion mechanism. To calculate the mass and inertia properties of every link comprising a link-motion punch press, 3-dimensional CAD software is utilized. The main issue in this work is to eliminate the first-order unbalance force and moment in a link-motion punch press. The mass, moment of inertia link length, location of the mass center in each link have a great impact on the degree of dynamic balancing which can be achieved maximally. Achieving good dynamic balancing in a link motion punch press is quite essential fur reliable operation at high speed.

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Development of the Massless Link Model including External Force and Bushing Deformation (외력과 부싱변형을 고려한 무질량 링크 모델 개발)

  • 손정현;최성태;김광석;유완석;이종년
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.1
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    • pp.163-170
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    • 2001
  • In this paper, a massless link model transmitting external forces is developed to achieve the numerical efficiency in simulation of vehicle suspension systems. Forces acting on links are resolved and transmitted to attached points with a quasi-static assumption. Also, a theoretical derivation and computer implementation of a massless link with bushing elements are proposed. In the massless link with bushing elements, one end is connected to the adjacent body with bushings and the other end is connected with a spherical joint. The deformation of a massless link with bushing elements is theoretically determined by minimizing the potential energy function with quasi-static equilibrium assumption at each time step. Several simulations with a full vehicle model are carried out to compare the efficiency of the developed massless link component. From the results, it is concluded that the proposed approach can reduce the computational time considerably.

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Link Budget Analysis of Communication System for Reliable WBAN (신뢰성있는 WBAN을 위한 통신 시스템의 링크 버짓 분석)

  • Roh, Jae-sung
    • Journal of Advanced Navigation Technology
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    • v.23 no.6
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    • pp.584-588
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    • 2019
  • Wireless body area network (WBAN) is a networking technology that enables early detection of abnormal health conditions, real-time medical monitoring, and telemedicine support systems. The internet of things (IoT) for healthcare, which has become an issue recently, is one of the most promising areas for improving the quality of human life. It must meet the high QoS requirements of the medical communication system like any other communication system. Therefore, the bit error rate (BER) threshold was chosen to accommodate the QoS requirements of the WBAN communication system. In this paper, we calculated BER performance of WBAN channel using IR-UWB PPM modulation and analyzed link budget and system margin of WBAN according to various system parameters.

Link Budget and Performance Analysis of UWB Transmission Method for Off-body HDR Communication in WBAN System (WBAN에서 신체 외 고속통신을 위한 UWB 전송 방식의 링크버짓 및 성능 분석)

  • Choi, Nack-Hyun;Hwang, Jae-Ho;Jang, Sung-Jeen;Kim, Jae-Moung
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.8 no.1
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    • pp.53-64
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    • 2009
  • For a realization of the ubiquitous society, applying IT to vehicle industry has recently been an attractive issue to make wireless communication in body area network possible to everywhere. In this paper, we propose the physical layer symbol structure based on PPM scheme of the IEEE 802.15.4a for the off-body high data rate WBAN system. We propose four symbol structures which is classified according to the number of the chip and whether the channel coding is used or not. We calculate the required SNR through the link budget calculation and the recently proposed off-body WBAN channel environment was applied in the simulation. The results of four systems show that small number of burst's chip enhances the performance and the system is capable to achieve the data rate of 10 Mbps.

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Vibration Control of a Single-Link Flexible Manipulator Using Reaction Moment Estimator (반력모멘트 추정기를 이용한 단일 링크 유연 조작기의 진동제어)

  • Shin, Hocheol;Han, Sangsoo;Kim, Seungho
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.2 s.95
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    • pp.169-175
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    • 2005
  • In this paper, a novel vibration control scheme for a single-link flexible manipulator system without using a vibration feedback sensor is proposed. In order to achieve the vibration information of the flexible link, a reaction moment estimator based on the dynamic characteristics of the flexible manipulator is proposed. While the manipulator is maneuvering the reaction moment is reciprocally acting on the flexible link and the hub inertia due to the vibration of the link. A sliding mode controller based on the equivalent rigid body dynamics corresponding to the proposed flexible manipulator is then augmented with the reaction moment estimator to realize a decentralized control system. The reaction moment estimator is implemented via the first order low pass filter. The performance of the proposed control scheme is verified by computer simulation and experiment.