• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1495-1499
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• 2003

There is some equipment that helps user to exercise and to walk. But almost all equipments require some physical strength of their muscles. So we developed a system that could assist walking action of the people with lower-limb disability. The system called as walking stand adopted the balancing mechanism which assures the stable walking, and the 4 link-based mechanism that had 2 degrees of freedom on each leg. The walking stand uses four motors and has two sets of the special link-structure to simulate the human walking mechanism. With our system, even serious disabled with lower-limb disability may enjoy walking rehabilitation. And by adjusting the power, it can be used as the walking assistant mechanism instead of conventional wheelchairs. Experiments showed that our walking stand is applicable to the rehabilitation and also to the mobile device in our daily life for those people who do not have enough physical ability to walk by themselves.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.840-849
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• 1993

In this paper, it is reported that manipulator and hand-required for harvesting tomato were studied. At first, basic physical properties of tomato plant were investigated such as position of fruit, length of stems and leaves, width between ridges and son on . Secondly , basic mechanism of articulate manipulators with 5 to 7 degree of freedom were investigated by using evaluation indexes such as operational space, measure of manipulatability , posture diversity and so on. From the results, an articulate manipulator with 7 degrees of freedom was selected and the manipulator was manufactured as a trial according to the mechanism. Thirdly , physical properties about fruit and peduncle of tomato were also researched such as diameter, length , picking force and so on. Based on the properties , tomato harvesting hand with absorptive pad were also made as a trial. Finally, after the hand was attached to the manipulator, harvesting experiment was done in greenhouse . It was observed th t the robot could harvest satisfactorily , not only since the robot adapted to physical properties of tomato plant was manufactured but also since phyllotaxis of tomatoes was so methodical that all fruit clusters emerged in the same direction.

• Journal of Korean Society of Disaster and Security
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• v.10 no.1
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• pp.1-10
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• 2017

Recently, increasing cases of ground subsidence in the urban area has become social issue, and related bill has been passed. Ground subsidence occurs through complex combination of various factors, and numerical analysis of this problem is limited thereby. This is why verification of ground subsidence mechanism has been conducted through physical modelling. Previous researches has been focused on modelling ground subsidence caused by utility pipe defects, and there has been insufficient physical modelling study on ground subsidence caused by various reasons such as groundwater flow and excavation activity. Also, most previous physical modelling studies were performed in 1g condition, which cannot take the in-situ stress condition into the evaluation of the ground subsidence mechanism. Therefore, in this study, physical modelling techniques to simulate various conditions is discussed by studying the previous researches on the ground subsidence mechanism through physical modelling. Also, centrifuge modelling test is suggested in this study as the technique to perform more reliable evaluation of ground subsidence mechanism. Lastly, this study suggests to apply the techniques used in the evaluation of ground subsidence mechanism into Ground Stability Assessment.

• The Journal of Korean Physical Therapy
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• v.12 no.3
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• pp.433-444
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• 2000

The purpose is paper was to discuss current concepts related to anatomic stabilizing structures of the shoulder joint complex and their clinical relevance to shoulder instability. The clinical syndrome of shoulder instability represents a wide spectrum of symtoms and signs which may produce various levels of dysfunctions, from subtle subluxations to gross joint instability. The glenohumeral joint attains functional stability through a delicate and intricate interaction between the passive and active stabilizing structures. The passive constraints include the bony geometry, glenoid labrum, and the glenohumeral joint capsuloligaments structure. Conversely, the active constraints, also referred to as active mechanism, include the shoulder complex musculature, the projprioceptive system, and the musculoligamentous relationship. The interaction of the active and passive mechanism which provide passive and active glenohumeral joint stability will be throughtly discussed in this paper

• The Journal of Korean Physical Therapy
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• v.13 no.2
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• pp.477-482
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• 2001

Until now, it has not been well known for Far-infrared(FIR) how to affect to the human body. We introduced and presumed the mechanism of FIR based on molecular biology in this study, as below. The human body is composed of proteins which get easily changed by a thermal factor (about 42 $^{\circ}$C over). FIR with low temperature can deeply penetrate on the human body composed things without troublesome, since FIR has effectively operated on the human body at low temperature (35-40 $^{\circ}$C). When FIR penetrated on the human body, it would inhibit the abnormal genes and cells expression, and then information of DNA and RNA would be reexpressed for arranging DNA and RNA abnormal state. As FIR's receptors in the body, it colud be presumed that N-glycosyl linkage of purine and deoxyribose, RNA splicing process, and heat shock protein.

• The Journal of Korean Physical Therapy
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• v.12 no.1
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• pp.49-56
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• 2000

The purpose of this study was to investigate the influnce of afferent stimuli, transcutaneous electrical nerve stimulation and ultra sound, on the electrdiagnostic study of normal subjects. Electrodiagnostic study was performed before and after the application of afferent stimulation of the right popliteal fossa on 18 healthy female volunteers. After the transcutaneous electrical nerve stimulation, there is no significantly change of latencies and amplitudes of SEP, H-reflex, peroneal nerve F-wave, and sensory nerve conduction. After the ultra sound, there is no significantly change of latencies and amplitudes of SEP, H-reflex, peroneal nerve F-wave, and sensory nerve conduction. Tibial nope F-wave and motor nerve shows prolonged latency after TENS and US (p<0.01). Ultrasound may have a similar mechanism of action compared to transcutaneous electrical nerve stimulation by having localized inhibitory effects of the peripheral nerve. However, further investigation is needed to assess their mechanism of action and the precise relevance of stimulation modality.

• Journal of International Academy of Physical Therapy Research
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• v.6 no.2
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• pp.902-907
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• 2015

The purpose of this study was to parallel circuit training and circuit training with sonic systemic mechanism was to compare the differences in pulmonary function and chest expansion in adult men. This study was performed on 20 subjects. 20 subjects were divided into two groups; Circuit training group(n=10), Circuit training with sonic systemic mechanism(n=10). Both of the group performed the exercise 3 times a week for 5 weeks. The data was analyzed by the Repeated t-test for comparing before, during and after changes of factors in each group and the Independent t-test for comparing the between groups. The result are as follows. Circuit training group was statistically significant difference FVC, FEV1/FVC(p<.05), Circuit training with sonic systemic mechanism group was statistically significant difference PEF, VC in pulmonary function(p<.05). Circuit training group was statistically significant difference FEV1/FVC of between the two group in pulmonary function(p<.05). Circuit training group and circuit training with sonic systemic mechanism group was statistically significant difference in chest expansion(p<0.05) and there was no statistically significant difference of between the two group in chest expansion(p>.05).

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.39.1-39.1
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• 2018

Although it is agreed that the gamma-ray bursts (GRBs) invoke highly relativistic jets with bulk Lorentz factors of a few hundreds, the exact physical mechanism producing such powerful gamma-rays still remains debated. Three outstanding and important questions in the field concern (1) the composition of GRB jets (i.e., matter-dominated vs Poynting-flux-dominated), (2) the involved radiative process responsible for the observed gamma-rays (i.e., synchrotron mechanism vs photospheric radiation), and (3) the distance of the emitting region from the central engine where the prompt gamma-rays are released (i.e., ~10^12 cm vs 10^14 cm vs 10^16 cm). I will present recent important breakthroughs that we have made, which answer these three questions.

• The Journal of Korean Physical Therapy
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• v.15 no.2
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• pp.146-156
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• 2003

Isolated rat thoracic aorta which is pharmacologically precontracted by phenylephrine induces photorelaxation when exposed to long wave length UV-light. The aim of the present study was to characterize the mechanism of UV-light induced by photorelaxation in the rat aorta. 1. UV light relaxed both endothelium-intact and -denuded rat aortic rings contracted by phenylephrine. The magnitude of relaxation on UV light was dependent on the exposure time and slightly greatly in endothelium-denuded rings than in endothelium-intact preparations. 2. L-NAME (10 nM - 100 $\mu$M) but not D-NAME completely inhibited the photorelaxation in a concentration dependent manner. 3. The UV-induced relaxation was inhibited by methylene blue (1 - 100 uM), and verapamil (100 nM), and removal of extracellular $Ca^{2+}$. In contrast, UV-light induced photorelaxation was potentiated by $N^{w}$-nitro-L-arginine (L-NNA) treatment. These results suggest that UV light-induced photorelaxation may be due to nitric oxide from exogenously administered L-arginine as well as endogenous nitric oxide donors such as amino acid and arginine derivatives

• Nuclear Engineering and Technology
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• v.54 no.6
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• pp.1962-1971
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• 2022

The liquid lead-lithium (Pb-17Li) blanket has many applications in fusion reactors due to its good tritium breeding performance, high heat transfer efficiency and safety. The compatibility of liquid Pb-17Li alloy with the structural material of blanket under magnetic field is one of the concerns. In this study, corrosion experiments China low activation martensitic (CLAM) steel and 316L steel were carried out in a forced convection Pb-17Li loop under 1.0 T magnetic field at 480 ℃ for 1000 h. The corrosion results on 316L steel showed the characteristic with a superficial porous layer resulted from selective leaching of high-soluble alloy elements and subsequent phase transformation from austenitic matrix to ferritic phase. Then the porous layers were eroded by high-velocity jet fluid. The main corrosion mechanism of CLAM steel was selective dissolution-base corrosion attack on the microstructure boundary regions and exclusively on high residual stress areas. CLAM steel performed a better corrosion resistance than that of 316L steel. The high Ni dissolution rate and the erosion of corroded layers are the main causes for the severe corrosion of 316L steel.