• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1130-1131
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• 2006

We found that the """interface reaction between Ni-based alloy bond, diamond, and steel core is very critical in bond strength of diamond tool. None element from metal bond diffuses into the steel core but the Fe element of steel core was easily diffused into the bond. This diffusion depth of Fe has a great effect on the bonding strength. The Cr in steel core accelerated the Fe diffusion and improved the bond strength, on the other hand, carbon decreased the strength. Ni-based alloy bond including Cr was chemically bonded with diamond by forming Cr carbide. However, the Cr and Fe in STS304 were largely interdiffused, the strength was very low. The Cr passivity layer formed at surface of STS304 made worse strength at commissure in brazing process.

• Journal of the Ergonomics Society of Korea
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• v.16 no.1
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• pp.73-83
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• 1997

It is improtant to get accurate information about the grip strength for designing ergonomic grips and handles. It has been known that the excessive and repetitive use of grip force and unnatural posture of the wrist may cause cumulative trauma disorders (CTDs) such as carpal tunnel syndrome, tendrome, tendonitis, DeQuervan's disease, etc. In this paper we have measured the grip strength for sitting and standing posture for Korean adults ; 114 males and 105 females aged from the 20's to above the 50's. And this paper performed statistical analysis for deriving characteristics between grip strength and anthropometric data. The results are as follows ; (1) The maximum grip strength posture is exerted under standing posture with the elbow in full extension (180 .deg. ) for both males and females (2) There is significant difference among posture, sex and right and/or left handedness (3) Grip strength decreases with age for male, but it traces an inverted U curve for female (4) Grip strength has corre- lations with the age, weight, height, BSA, forearm length, hand length, thickness of wrist, circumference of wrist, and breadth of wrist for males.

• PNF and Movement
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• v.12 no.1
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• pp.45-50
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• 2014

Purpose: Deficits in upper-extremity function in individuals with tetraplegia are primarily due to the loss of motor pathways. The purpose of this case report is to describe the effect of closed kinetic chain exercise using PNF on hand function and ADL of patient with incomplete spinal cord injure. Methods: Patient was a 53-year-old man with C4 tetraplegia and hand and upper extremity impairment who participated in this training intervention for 10 weeks. Results: Patient demonstrated improvements in upper extremity strength, hand function and performance of ADL. Outcome measures(ASIA motor scale, Hand power, Jebsen-Taylor Hand Function test, SCIM) were measured before and after the training program. Conclusion: The results of this case suggests that an closed kinetic chain exercise program in incomplete spinal cord injury patient may induce Hand function and ADL.

• Journal of Technologic Dentistry
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• v.36 no.1
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• pp.1-7
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• 2014

Purpose: The aim of this study was analyzed by comparing the effect of glass fiber reinforcement addition on the strength of resin denture base. It was intended to provide a reference data useful for clinical application. Methods: The test specimens (length $64.0{\pm}0.1mm$, width $10.0{\pm}0.1mm$, thickness $1.0{\pm}0.1mm$, $1.5{\pm}0.1mm$, and $2.0{\pm}0.1mm$ respectively) were made. In the experimental groups resin denture base reinforced with glass fiber were fabricated. In the control groups resin denture base were fabricated by conventional method. After specimen fabrication was completed, transverse test was performed using a universal testing machine. Results: The transverse strength value in CON group was $83.08{\pm}9.07MPa$ for 1.0 mm, which ranked the highest in value. On the other hand, the value was $56.07{\pm}5.15MPa$ for 2.0mm, which ranked the lowest in value. And CON+SES group was $119.80{\pm}30.70MPa$ for 1.0mm, which ranked the highest in value. On the other hand, the value was $84.00{\pm}7.97MPa$ for 2.0mm, which ranked the lowest in value. Also, the flexural modulus value in CON group was $2,983.10{\pm}506.92MPa$ for 1.0mm, which ranked the highest in value. On the other hand, the value was $1,257.64{\pm}230.48MPa$ for 2.0mm, which ranked the lowest in value. And CON+SES group was $4,679.41{\pm}1578.29MPa$ for 1.0mm, which ranked the highest in value. On the other hand, the value was $2,512.36{\pm}527.09MPa$ for 2.0mm, which ranked the lowest in value. Conclusion: The reinforced glass fiber increased the strength of resin denture base, effected to reduce the thickness of resin denture base.

• Journal of Korean Physical Therapy Science
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• v.20 no.1
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• pp.61-67
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• 2013

Purpose : The purpose of this paper is to figure out the effects of the Powerball exercise on grip strength, tip pinch and key pinch. Methods : Twenty subjects participated in this experiment. Spin right wrist counterclockwise for five minutes holding Powerball after making main joint of right hand -predominant hand- into elbow flexion and forearm pronation. Results : 1. Before and after Powerball exercise, when we compared the grip strength of men and women, there was a significant difference. 2. Before and after Powerball exercise, when we compared tip pinch of men and women, there was a significant difference. 3. Before and after Powerball exercise, when we compared key pinch of men and women, there was a significant difference. 4. Before and after Powerball exercise, there was no significant difference between men and women. Conclusion : From what using Powerball exercise influenced grip strength, tip pinch and key pinch positively, we assume that it will be considered a great expectation to improve grip strength, tip pinch and key pinch in the future and it would be better to conduct this experiment in depth to a lot of people.

• Physical Therapy Korea
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• v.17 no.4
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• pp.77-87
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• 2010

The present case study highlights the effects of a novel Comprehensive Hand Repetitive Intensive Strengthening Training (CHRIST) on morphological changes and associated upper extremity (UE) muscle strength and motor performance in a child with spastic quadriplegic cerebral palsy (CP). The Child, a 10-year-old girl with spastic quadriplegic CP, was treated with CHRIST for 60 minutes a day, five times a week, for 5 weeks. The CHRIST was designed to improve motor function and strength. Clinical tests including the modified Wolf Test, Jebsen-Taylor Hand Function Test, and Pediatric Motor Activity Log questionnaire were used to determine motor function. Ultrasound imaging was performed to determine the changes in the cross-section area (CSA) of the extensor carpi radialis (ECR) and triceps brachii (TRI). Muscle strength was measured with a dynamometer at pretest, and post-test, and 3-month follow-up. Ultrasound imaging data showed that the CSAs of both ECR and TRI muscles were enhanced as a function of the intervention. These changes were associated with muscle strength and motor performance and their effects remained even at a 3-month follow-up test. Our results suggest that the CHRIST was effective at treating muscle atrophy, weakness and motor dysfunction in a child with spastic quadriplegic CP.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.11
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• pp.2752-2761
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• 1993

The purpose of this study is to confirm the decreasing problems of residual bending strength, and the fracture machanism experimentally when CFRP composite laminates are subjected to Foreign Object Damage. Composite laminates used for this experiment are CFRP orthotropy laminated plates, which have two-interfaces [O/sub 6//sup o//90/sub 6//sup o/]sub sym/ and four-interfaces [O/sub 3//sup o//90/sub 6//sup o//O/sub 3//sup o]/sub sym/. When the specimen is subjected to transverse impact by a steel ball, the delamination area generated by impact damage is observed by using SAM(Scanning Acoustic Microscope). also, Thefracture surfaces obtained by three-point bending test were observed by using SEM (Scanning Electron Microscope). Then, fracture mechanism was investigated based on the observed delamination area and fracture surface. The results were summarized as follows; (1) It is found that for the specimen with more interface, the critical delamination energy is increased while delamination-development energy is decreased. (2) Residual bending strength of specimen A is greater than that of Specimen B within the impact range of impact energy 1. 65J (impacted-side compression) and 1. 45J (impacted-side tension). On the other hand, when the impact energy is beyond the above ranges, residual bending strength of specimen A is smaller than that of specimen B. (3) In specimen A and B, residual strength of CFRP plates subjected to impact damage is lower in the impacted-side compression than in the impacted-side tension. (4) In the case of impacted-side compression, fracture is propagated from the transverse crack generat-ed near impact point. On the other hand, fracture is developed toward the impact point from the edge of interface-B delamination in the case of impacted-side tension.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.2
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• pp.1-13
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• 2023

Purpose : Along with the rapid development of digital technology, the application of digital healthcare in the medical field is also increasing. According to many experts, increasing the amount of exercise and physical activity is a helpful way to prevent and manage physical problems in modern society. However, a lack of exercise, which is of the lifestyle of modern people, leads to the development of various diseases. This study aimed to examine the effects of digital exercise intervention using artificial intelligence (AI) on the physical abilities of adults whether digital exercise intervention can be a reliable and effective therapeutic option for musculoskeletal disorders in real-world clinical settings. Methods : In this study, exercise was conducted using a digital application to investigate the effects of an AI-based digital exercise intervention on the physical abilities of adults. A total of 13 adults were evaluated, and their physical abilities before and after the exercise intervention were compared. Hand-grip strength, functional leg muscle strength, dynamic balance, and quadriceps muscle strength were assessed. Exercise was performed using a digital application and in a non-face-to-face manner. AI identified the exercise status of each participant and adjusted the exercise difficulty level accordingly. The exercised daily for 4 weeks. Results : A total of 12 participants were analyzed for the final results. Significant improvements were observed in hand-grip strength, functional leg muscle strength (evaluated using the stand-up test), dynamic balance, and straight-gait ability (p<.05), indicating an increase in the overall muscular strength and physical function of the participants. Conclusions : Digital exercise intervention using AI is effective in improving physical abilities related to musculoskeletal function. It can be useful in clinical practice as an effective treatment option for patients with musculoskeletal disorders or muscle weakness.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.95-101
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• 1999

This study was performed to evaluate the characteristics of workability and strength of the concrete containing mineral admixtures such as flyash, blast furnace slag, zeolite powder. As a result, considering their workability and strength, the optimum replacement ratio of them to plain concrete were obtained for each ternary admixture. This increased compressive strength was ascribed to both the closer parkinof fine particles and pozzolan reactivity of powders. This work showed that could be effectively utilized as a blending material without any decrease in the strength of early hydration stage. On the other hand, we found that the compressive strength at early ages ternary ordinary and high strength concrete untill 7 days was small, but that ternary concrete at 28days was highly increased about 31% and 15% extent.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.853-858
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• 2000

According to the results of this research, Production of Fold Mortar Permanent - Form was found to be possible by Mortar. Th FP-Form (Fold Permanent-Form) mortar had compress strength 580kgf/$\textrm{cm}^2$. FP-Form model was made by the result of the first research. There was no minute-crack on beam form and the outer surface of form was very smooth, and those qualities it were made possible hand-mad by experiment. This study is about bond strength progress of FP-Form that developed for the form work rationalization and systematization. The result of this study follows; (1) Fluidity and strength development of mortar which used for FP-Form are satisfied (2) After study on getting good bond strength progress, inside-uneven type presents the better suitableness, and wire netting V-type presents the better shear strength.