• Journal of Sensor Science and Technology
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• v.29 no.3
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• pp.205-210
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• 2020

The aim of this study is to develop a vertical vibration compensator that attenuates the vertical vibration of ships. The vibration compensator was designed according to the principle of generating vertical excitation forces by rotating two eccentric bodies of the same mass in opposite directions at the same rotational speed. In addition, the structural stability was analyzed using the finite element method. The maximum stress in the drive shaft was 95.6 MPa, which was approximately 35% of the allowable stress of the shaft material (SM45C, 270 MPa). The acceleration signals of the vibrator compensator body and the testbed were determined to evaluate the efficiency of the vibration compensator and the designed excitation forces. Subsequently, the excitation forces were estimated based on the relationship between force and acceleration. The estimated results were very close to the theoretical values with an error of less than 3%.

• Journal of Korean Medicine Rehabilitation
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• v.20 no.1
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• pp.167-182
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• 2010

Objectives : The purpose of this study is to find correlation about 7-Zone-Diagnostic System and Clinical Parameters using Oriental Health Examination. Methods : Subjects of our study were 325 cases who took Oriental Health Examination. We collected the data of body composition analysis, 7-Zone-Diagnostic System, blood analysis and devided by 7-Zone-Diagnostic system to acceleration, normalcy and depression. Results and Conclusions : The values of muscle mass, body fat mass, abdomen obesity rate, right arm water index, left arm water index, trunk water index, right leg water index, left leg water index, BMI, BMR, GOT, GPT, ${\gamma}$-GTP, BUN, TC, triglyceride and hemoglobin were continuous with 7-Zone-Diagnostic system.

• Journal of computational fluids engineering
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• v.12 no.1
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• pp.1-8
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• 2007

A code is developed using the hybrid Cartesian/immersed boundary method and it is applied to simulate flows around a three-dimensional deforming body. A new criterion is suggested to distribute the immersed boundary nodes based on edges crossing a body boundary. Velocities are reconstructed at the immersed boundary nodes using the interpolation along a local normal line to the boundary. Reconstruction of the pressure at the immersed boundary node is avoided using the hybrid staggered/non-staggered grid method. The developed code is validated through comparisons with other experimental and numerical results for the velocity profiles around a circular cylinder under the forced in-line oscillation and the pressure coefficient distribution on a sphere. The code is applied to simulate the flow fields around a plate whose tail is periodically flapping under a translation. The effects of the velocity and acceleration due to the deformation on the periodic shedding of pairs of tip vortices are investigated.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.9
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• pp.203-211
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• 1999

The research committee for automobile repairs (RCAR), an international body of insurance research centers, has adopted the typical low speed crash test based on an average damage level in crash accidents to estimate the damageability , repairability and safety. The characteristics of body acceleration and the probability of injury are investigated based on damaged components, accelerations of body and injured dummy to analyze damageability and the driver's safety under low speed crash environment. It is found from the experimental results that the probability of head and thorax injuries are very low comparing to the injury criteria of FMVSS No.208. Furthermore, it is suggested that the deployment of airbag may not be necessary at RCAR low speed frontal crash test.

• Journal of KSNVE
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• v.10 no.2
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• pp.269-279
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• 2000

This paper deals with the development of biomechanical model on a seat with backrest support in the vertical direction. Four kinds of biomechanical models are discussed to depict human motion. One DOF model mainly describes z-axis motion of hip, two and three DOF models describe z-axis of hip and head, and while nine DOF model suggested in this study represents more motion than the otehr model. Three kinds of experiments were executed to validate these models. The first one was to measure the acceleration of the floor and hip surface in z-axis, the back surface in x-axis, and the head in z-axis under exciter. From this measurement, the transmissiblities of each subject were obtained. The second one was the measurement of the joint position by the device having pointer and the measurement of contact position between the human body and the seat by body pressure distribution. The third one was the measurement of the seat and back cushion by dummy. The biomechanical model parameters were obtained by matching the simulated to the experimental transmissiblities at the hip, back, and head.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1403-1407
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• 2007

The bogie of Rolling Stock is the basic rolling component. It operates the train body, guides the body considering various tracks and offers comfort to passengers. We can verify the safety level of bogie about all factors through the first -grade scenario of Preliminary Hazard Analysis, but especially the horizontal acceleration sensor, equipped in each power bogie and trailer bogie, is the device, which makes it possible to test bogie instability and uncomfortable body movements by the method, similar to actual train driving, and in this context the necessity of this device becomes important. This paper would classify the main functions of driving sub system and examine the reliability, availability, maintainability and safety, which are main factors of RAMS. Especially, we would realize the bogie instability sensor with a simulator and offer the content in analyzing the data by the statistical method, which are obtained through the connected test with OBCS.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.415-418
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• 2013

This paper presents an electromagnetic kinetic energy harvester which is suitable for supplying power for body-worn sensors and personal electric devices. Human motions are investigated by measuring the acceleration signal at each points of the body during walking and running. The dynamic characteristics of the harvester can be calculated from the transfer function of the system. The transduction factor can be calculated from the electromagnetic field analysis by Maxwell software. The prototype of the harvester is designed and manufactured. The theoretical power characteristics are compared with the experiment results.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.8
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• pp.661-667
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• 2004

The characteristics of noise and vibration by a heavy impact source was studied. The triggering method was used for increasing the reliability and stability to measure the level of sound pressure. sound intensity and vibration acceleration. A simple finite element model and a rigid body analysis method were suggested to calculate the natural frequencies of the multi-layer floor system. The results show that the resilient materials decrease the natural frequency of the reinforced concrete slab, make a resonance with dominant driving frequency in the low frequency region, and increase the vibration and noise level. A simple finite element model and rigid body models was suggested to calculate the natural frequencies of the floor systems.

• Clinical and Experimental Pediatrics
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• v.61 no.12
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• pp.375-380
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• 2018

With the increase in the prevalence of overweight and obesity worldwide, early adiposity rebound, which is known to have a strong association with obesity, has recently been a focus of research. Early adiposity rebound is conventionally known to have a close relationship with non-communicable diseases. However, novel insights into early adiposity rebound have implied an acceleration of growth and puberty, which is directly reflected in the trends in the timing of adiposity rebound, in the 21st century compared with in the past. Furthermore, the observation that lean mass changes rather than fat mass changes show a more similar pattern to body mass index trajectories is interesting. In this article, the later outcomes and risk factors of early adiposity rebound are briefly summarized, and the current trends in the timing of adiposity rebound and novel insights into its relationship with body composition are reviewed.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2721-2724
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• 2003

This paper deals with a manipulability analysis of multi-legged walking robots in acceleration domain, that is the dynamic manipulability analysis of walking robot. Noting that the kinematic structure of the walking robot is basically the same with that of the multiple serial robot system holding one object, the analysis method for cooperating robot is converted to that of walking robot. With the proposed method, the bound of achievable acceleration of the moving body is easily derived from the given bounds on the capabilities of Joint torques. Several walking robot examples are analyzed with proposed method under the assumption of hard contact, and presented in the paper to validate the method.