• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2004.11a
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• pp.114-114
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• 2004

• Physical Therapy Korea
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• v.27 no.1
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• pp.11-18
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• 2020

Background: As technology has progressed, various robot-assisted devices have been developed to reduce therapists' labor and assist in therapy. However, due to their many limitations, it is more practical to use traditional mechanical devices. The grahamizer is one such traditional mechanical device used clinically to rehabilitate the upper extremities. No study has yet established the efficacy of the grahamizer in individuals with stroke. Objects: This study investigated the immediate change in arm reaching after the use of a grahamizer. Methods: Twenty-two stroke survivors participated in this study (11 males and 11 females). The reaching of the more-affected arm was measured three times using the three-dimentional electromagnetic motion tracking system "trakSTAR". After the first measurement, the subjects performed 500 rotatory arm exercises using the grahamizer. To assess the grahamizer's effect, the subjects were remeasured in the same way. Results: There were significant increases in the reaching distance (p < 0.05) and movement smoothness (p < 0.05) of the more-affected arm after using the grahamizer. Conclusion: Our study confirms that using the grahamizer is beneficial in the rehabilitation for improving movement of the more-affected arm in stroke survivors.

• Korean Journal of Materials Research
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• v.31 no.6
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• pp.339-344
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• 2021

Composite materials offer distinct and unique properties that are not naturally inherited in the individual materials that make them. One of the most attractive composites to manufacture is the aluminum alloy matrix composite, because it usually combines easiness of availability, light weight, strength, and other favorable properties. In the current work, Powder Metallurgy Method (PMM) is used to prepare Al2024 matrix composites reinforced with different mixing ratios of yttrium oxide (Y₂O₃) particles. The tests performed on the composites include physical, mechanical, and tribological, as well as microstructure analysis via optical microscope. The results show that the experimental density slightly decreases while the porosity increases when the reinforcement ratio increases within the selected range of 0 ~ 20 wt%. Besides this, the yield strength, tensile strength, and Vickers hardness increase up to a 10 wt% Y₂O₃ ratio, after which they decline. Moreover, the wear results show that the composite follows the same paradigm for strength and hardness. It is concluded that this composite is ideal for application when higher strength is required from aluminum composites, as well as lighter weight up to certain values of Y₂O₃ ratio.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.345-350
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• 1999

In this study the results of investigation on the physical and mechanical properties of a rockfill dam body were provided. On the crest of the old Namgang dam to be excavated partially, various in-situ tests(boring with SPT, sampling of undisturbed sample, field density test, field permeability test) and geophysical investigation works were performed Rock materials, i.e., shale and sandstone, were collected, and their slake durability was evaluated using slaking durability testing method which is suggested by ISRM.

• Journal of the Korea Furniture Society
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• v.11 no.1
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• pp.75-84
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• 2000

Ginkgo trees have long been planted in Korea as roadside trees and ornamental trees, but the wood was seldom used except some utilization for small artifacts. Soaring prices of imported wood and future uncertainty about long-term supply of foreign woods have stimulated research on value-added utilization of less-utilized domestic wood resources such as Ginkgo wood. The properties of Ginkgo wood were investigated to determine its utilization potential in this study, and the results of anatomical, physical, and mechanical studies were presented with chemical compositions.

• 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.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.4
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• pp.801-810
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• 1998

Modeling and analysis of dynamic systems generally demand their resutls to be interpreted each other with a physical sense. It sometimes requires that there should exist a unified tool in the treatment of dynamic systems which can be applied to both their modeling and analysis equally. This paper shows how models just after the progress of modeling via bond graph standards are converted to ones which are appropriate for analyzing a dynamic system in the frequency domain. Four bond graph prototypes are introduced to obtain frequency properties of dynamic systems such as zero stability, relative order, zero and pole dynamics, etc. directly from bond graphs, and the method are proposed which reduces nearly all models of bond graph standards to one of the prototypes without any change of physical similarity. This procedure as a tool for the structural reduction of bond graphs and finding frequency properties of a dynamic system is further investigated to survey its effectiveness through an example.

• Fashion & Textile Research Journal
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• v.7 no.1
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• pp.106-110
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• 2005

This research surveys the mechanical properties of worsted fabrics for garment according to the loom characteristics and fabric positions with relation to the warp and weft weaving tensions on the projectile and air-jet looms, which is previously surveyed in the 1st paper. For this purpose, the grey fabrics are processed in dyeing and finishing processes. The mechanical properties of the finished fabrics are measured and discussed with relation to the warp and weft weaving tensions of projectile and air-jet looms and the variations of the fabric mechanical properties according to the fabric positions are also surveyed for investigating the homogeneity of the tailorability and fabric hand.

• Fashion & Textile Research Journal
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• v.6 no.6
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• pp.772-777
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• 2004

This research surveys the mechanical properties of worsted for garment according to the loom characteristics and fabric positions with relation to the warp and weaving weft tensions on the 3 types of rapier looms, which is previously surveyed in the 1st paper. For this purpose, the grey fabrics are processed in dyeing and finishing processes. The mechanical properties of the finished fabrics are measured and discussed with relation to the warp and weft weaving tensions of 3 types of rapier looms and the variations of the fabric mechanical properties according to the fabric positions are also surveyed for investigating the homogeneity of the tailorability and fabric hand.

• Structural Engineering and Mechanics
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• v.63 no.5
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• pp.597-605
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• 2017

Our work aims to analyze using the finite element method the evolution of the stress intensity factor (SIF) parameter K of three laminated folded plates stacks [$+{\alpha}$, $-{\alpha}$], made of the same epoxy matrix and different reinforcement fibers (boron, graphite and glass). Our results show that the angle of orientation of the boron/epoxy composite has no great influence on the variation of the parameter KI. Compared to composite graphite/epoxy and glass/epoxy, the laminated composite boron/epoxy reduces more the SIF KI in the middle of the plate for angles $0^{\circ}{\leq}{\alpha}{\leq}30^{\circ}$.