• Composites Research
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• v.20 no.3
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• pp.31-36
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• 2007

A quantitative prediction method for initial crack length in a carbon/epoxy (CF/EP) composite beam using active piezoelectric transducers was established in this study. Wavelet Transform (WT)-based signal processing and identification technique in time-frequency domain was developed to facilitate the determination of damage presence and severity. Dynamic response of a CF/EP composites beam containing a continuously expanding crack, coupled with a pair of active piezoelectric disks, was examined under a narrow band excitation, and then applied with the proposed signal processing technique.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.793-796
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• 2003

This study dealt with the manufacturing process of self-healing microcapsules for damage repair in polymeric composites. The microcapsule was consisted with a DCPD (dicyclopentadiene) as the healing agent and a urea-formaldehyde resin as the wall section. The size distribution of microcapsules were measured by a particle size analyzer using a laser diffraction technique. Thermal stability of microcapsules was investigated by using a TGA under continuous and isothermal heating conditions. According to the results, these microcapsules were verified to be to thermally stable and have a great potential to be applicable for damage repair in polymeric composites.

• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.130-131
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• 2003

수술용으로 쓰이는 치과용 레이저로는 Nd：YAG, $CO_2$, Er：YAG 레이저들이 있다. 치료 부위에 따라 두 가지 응용으로 나눌 수 있다. 잇몸의 절개 등은 주로 $CO_2$나 Nd：YAG 레이저를 이용하여 정밀하게 그리고 출혈을 최소로 하는 레이저의 장점을 살리면서 시술하고 있다. $CO_2$레이저의 경우 강한 열적 손상작용 때문에 출력 조사 시간을 짧게 하여 사용하며, 열적 손상력이 낮은 Nd：YAG 레이저는 화이버를 접촉식으로 하여 화이버의 작은 면적의 높은 광밀도를 이용하여 시술하고 있다. (중략)

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.419-422
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• 2016

Recently, there are a lot of report about the safety accident in laser equipment for example laser pointer, laser level, laser distance meter, temperature measurement equipment and so on. But most of people doesn't care of the safety, and some of the people were damaged by laser in the retina and skin. So in this reaserch So in this thesis, research the safety control rules in global and domestic regulations and international standard IEC 60825-1. From the above research, develop the safety control rules to improve the consumer safety.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.339-341
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• 2022

이 연구는 현 트렌드에 발맞추어 손상예방, 트레이닝 수업에 보다 양질의 피드백을 제공하여 보다 효율적이고 효과적인 교육프로그램 개선 및 개발하는데 목적이 있다. 부하가 증가될수록 우측 외측광근, 대퇴이두근과 좌측 내측광근, 대퇴이두근, 비복근이 활성도과 증가하였으며, 발의압력은 앞쪽이 증가하였으며 COG 좌/우 안정성이 감소하였다. 초보자들은 자신의 동작이 정확히 인지하고 수행하는지 어려움을 가지고 있으며 선수와 숙련자들은 강력한 근육을 바탕으로 보상작용을 수행해서 정확한 동작을 만들어 결국 근육의 불균형으로 인한 손상을 유발하기도 한다. 이러한 문제점을 웨어러블 기기를 이용하여 즉각적인 피드백을 제공할 수 있어 효율적인 운동지도를 할 수 있을 것으로 생각된다.

• Journal of the Korean Orthopaedic Association
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• v.54 no.5
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• pp.384-392
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• 2019

Ultrasonography is used for making the diagnosis and treatment decisions for those patients who complain of shoulder pain related with sports activity. Ultrasonography is especially helpful for diagnosing issues with the rotator cuff, the long head of biceps tendon and the acromio-clavicular joint. The medical decisions about shoulder pain can be promptly made when portable ultrasonography is used in the field of sports.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.2
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• pp.51-59
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• 2019

There is increasingly more research focusing on the application of FRP reinforcing bars as an alternative material for steel reinforcing bars, but most such research look at short term behavior of FRP reinforced structures. In this study, the microscopic analysis and tensile behavior of Basalt and Glass FRP bars under freezing-thawing and alkaline conditions were experimentally evaluated. After 100 cycles of the freezing and thawing, the tensile strength and elastic modulus of FRP bars decreased by about 5%. In the case of microstructure of FRP bars during the initial 20 days, no significant damages of FRP bar sections were found under $20^{\circ}C$ alkaline solution; however, the specimens immersed in $60^{\circ}C$ alkaline solution were found to experience resin dissolution, fiber damage and the separation of the resin-fiber interface. In the alkaline environment, the strength decrease of about 10% occurred in the environment at $20^{\circ}C$ for 100 days, but the tensile strength of FRPs exposed for 500 days decreased by 50%. At temperature of $40^{\circ}C$ and $60^{\circ}C$, an abrupt decrease in the strength was observed at 50 and 100 days. Especially, the tensile strength decrease of Basalt fiber Reinforced Polymer bars showed more severe degradation due to the damage caused by dissolution of resin matrix and fiber swelling in alkaline solution. Therefore, in order to improve the long-term performance of the surface braided FRPr reinforcing bars, surface treatment is required to ensure alkali resistance.

• Clinics in Shoulder and Elbow
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• v.13 no.2
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• pp.280-285
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• 2010

Purpose: Coracoid impingement syndrome refers to subscapularis impingement between the coracoid process and lesser tuberosity of the humerus, and pain may occur when the arm is positioned in forward flexion, internal rotation and adduction. This position is common for archers. Material and methods: A female archer with coracoid impingement syndrome that was uncontrolled by conservative therapy underwent arthroscopic subcoracoid decompression. At the 20th postoperative month of follow up, she complained of painful rotator interval widening and so she underwent arthroscopic rotator interval plication. Results: At the postoperative 6th month of follow up after the second operation, she showed no pain and good functional results, and she returned to competing as an archer. Conclusion: We have reported here on a case of successful treatment of painful rotator widening after subcoracoid decompression in an elite archer.

• Journal of the Korean Applied Science and Technology
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• v.37 no.3
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• pp.625-634
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• 2020

The purpose of this study is not only to define and cause of sarcopenia and frailty due to aging, but also to explore prevention and delay through regular exercise and right nutrition. Sarcopenia and frailty are known to cause frailty, cachexia, osteoporosis, metabolic syndrome and early death due to decreased muscle mass and muscle function caused by aging. The two disease were related to nervous system damage and lack of protein synthesis within the muscles due to the increase in the amount of oxidative stress, and inadequate nutrition and lack of physical activity. It also emphasizes the role and importance of right nutrition and physical activity (such as aerobic exercise, resistance movement, etc) to prevent and improve such syndromes. Conclusions, it is in proposing the supply of high-quality protein, including regular exercise, as the most beneficial way to prevent and overcome aging-related sarcopenia and frailty.

• Journal of Digital Convergence
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• v.15 no.2
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• pp.411-419
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• 2017

This study was to investigate whether a trunk correction taping plus scapular setting exercises has an effect on trunk muscle activation and trunk balance and upper extremity function in patients with stroke. Twenty stroke patients were randomly divided into a trunk correction taping with scapular setting exercise group (n=10) and a scapular setting exercise group (n=10), and each group performed given interventions for 30 minutes for 4 weeks. In the experimental group, there were significant increases in muscle activation, K-TIS, and MFT (p<.05), and a significant improvement was detected in K-TIS and MFT compared to the control group (p<.05). This study suggests that a trunk correction taping with scapular setting exercises was more effective on trunk muscle activation, trunk balance, and upper extremity function in stroke patients compared to a scapular setting exercise. It could be clinically more significant if the change in the onset time of muscle activity is confirmed in the further researches.