• EDISON SW 활용 경진대회 논문집
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• 제6회(2017년)
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• pp.194-203
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• 2017

The center of percussion(COP) is the point of an extended massive object attached to a pivot where a perpendicular impact will produce no reactive shock at the pivot. COP is an important concept in the field of vibration and dynamics. In vibration, COP causes reduction of vibration and in dynamics, it brings about maximum speed of an object. Many studies about COP are still in progress. However most of the researches have typically focused on the method of mathematical and numerical anlalysis. In this paper, impact analysis was proved by the mechanical energy method using EDISON co-rotational plane beam transient analysis program. The result expressed in acceleration was the relative magnitude of the impulse, which was the indicator of COP. Then, these results were compared with the reference thesis results for exact consequences. Additionally, parametric study of COP was conducted.

• 인간행동과 음악연구
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• 제11권2호
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• pp.1-18
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• 2014

본 연구는 청소년의 문제 행동 특성을 충동성향과 우울성향으로 분류하고 각 성향에 따라 그룹 즉흥연주 패턴에 차이가 있는지 알아보고자 하였다. 서울 소재 중학교에 재학 중이며 정서 행동문제를 보이는 청소년 40명이 본 연구에 참여하였고, 남녀 각 두 그룹씩 총 4개 그룹을 대상으로 타악기 즉흥연주 프로그램이 45분씩 총 2회 실시되었다. 그룹 내 리듬 연주 패턴이 분석되었고 악기 선택, 연주 강도 및 템포, 연주 지속 시간에 있어서의 그룹별 데이터 수집이 이루어졌다. 연구 결과 성향별 그룹 간 즉흥연주 리듬형에 있어서는 유의미한 차이가 나타난 반면, 악기 선택에 있어서는 두 그룹 간 차이가 유의미하지 않았다. 즉흥연주의 강도, 템포, 지속 시간과 관련하여, 강도에 있어서는 문제 행동 특성별 유의미한 차이가 없었던 반면, 템포와 지속 시간에 있어서는 그룹 간 통계적으로 유의미한 차이가 나타났다. 충동성향 그룹의 경우 우울성향 그룹과 비교해 연주 템포가 빠른 것으로 분석되었고, 평균 즉흥연주 지속시간은 짧은 것으로 나타났다. 연구 결과를 바탕으로 치료사가 음악치료 환경 내 즉흥연주에서의 대상별 리듬표현의 특징을 알고, 음악적 변인이 치료적으로 유의미하게 사용되도록 도울 수 있다는 데 본 연구의 의의가 있다. 청소년 대상군의 음악적 자기표현에 대한 치료사의 다층적인 이해와 그에 따른 민감한 반응은 자기표현 및 자기정체성 확인을 위한 해당 대상군의 음악적 시도를 촉진시키고, 청소년을 대상으로 즉흥연주 중심의 중재 효과성을 높이는 데 도움을 줄 수 있을 것으로 사료된다.

• Restorative Dentistry and Endodontics
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• 제12권1호
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• pp.149-153
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• 1986

Clinical analysis on early evidence of the pulp response to composite resin filling (27 cases) was made and reached to the results as follow; 1. Under age 40's early symptome was reported within the 1st, 2nd, 3rd and 4th week after composite filling evenly and age 50's reported after 4th week. 2. Sensitive response to cold were 11 cases, to warm 3 cases and to both (cold, warm) were 9 cases. 3. Tenderness to percussion and light pressure on apical area were 5 cases.

• 대한치과의사협회지
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• 제54권5호
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• pp.365-373
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• 2016

Purpose: Cemental tear is a specific type of root surface fracture characterized by a complete separation of a cemental fragment along the cementodentinal junction or a partial split within the cementum along an incremental line. It is suggested to be a factor for periodontal or periapical tissue destruction. The aim of this study is to present a diagnosis and treatment of cemental tear associated with periapical lesion with root canal treatment and regenerative periodontal surgery. Treatments: A 60-year-old male who had a history of sports trauma on the mandibular right central incisor about 10 years ago presented with apical cemental tear. Clinical examination showed a slightly dark yellowish discoloration and sinus tract that was located on the apical labial mucosa. The mobility and percussion were also assessed on the diseased tooth and recorded as $Miller^{\circ}{\phi}s$ Class II and tenderness to percussion. The probing depth was within the normal limit (<3 mm). Radiographic examination revealed a radiolucent lesion at the apical area and extended to distal aspect of the tooth along the fragment of cemental tear. After root canal treatment, periapical surgery was performed. The bony defect was exposed and then the detached root fragment was removed. Apical root resection and retrograde filling with Mineral Trioxide Aggregate (MTA) were accomplished and the bony defect was filled with deproteinized bovine bone mineral (DBBM) and covered with biodegradable collagen membrane. Results: After 9-month follow-up, healing of the mandibular right central incisor was uneventful and no swelling, purulence or pain was revealed in the associated area. Probing pocket depth was favorably stable, and the tooth mobility was decreased to the Miller's Class I. Conclusions: Apical cemental tear associated periapical lesion could be successfully treated with removal of the detached cementum in combination with apical surgery and GTR procedure.

• 대한약침학회지
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• 제12권1호
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• pp.35-42
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• 2009

1. Objectives To evaluate effects of bee venom acupuncture on cardiovascular system and differences according to each constitution. 2. Methods Heart rate variability, pulse wave and the velocity of cerebral blood flow were measured before bee venom acupuncture(BVA), right after and after 30 minuets, had been applied to 20 subjects. 3. Results 1. BVA did not have effects on measurement variables of heart rate variability. 2. BVA had effects on pulse wave, showing total time, radial augmentation index up and height of percussion wave, time to percussion wave, sum of pulse pressure down. 3. BVA did not have effects on the cerebral blood flow velocity when considering not Sasang Constitution. 4. Considering Sasang Constitution, BVA demonstrates different responses in time to preincisura wave, mean blood flow velocity, peak systolic velocity and end diastolic velocity. 4.Conclusion From those results, the following conclusions are obtained. Cause BVA alters pulse wave and makes differences in the cerebral blood flow velocity according to Sasang Constitution. Various methods of BVA treatment are needed considering Sasang Constitution.

• 헤리티지:역사와 과학
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• 제39권
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• pp.281-314
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• 2006

Several explanations exist about the usage of disk-shaped bronze implements in the ancient society. Some argue that they were used as mirrors, others suggest percussion instruments, and still others bronze ornaments. Differences between disk-shaped bronze implements and mirrors with multiple knobs are that the former have no visible design, only one handle, and a sharp curvature unlike the latter with smooth curvature. The question is whether disk-shaped bronze implements excavated from Korean peninsula have any light reflecting function. To answer this question, I carefully studied the concave surfaces of disk-shaped bronze implements excavated from Goejeong-dong, Tongso-ri and Hapsong-ri sites. The main findings are as follows: (1) The concave sides of the disk-shaped bronze implements excavated from Goejeong-dong and Tongso-ri sites were highly polished, and they were as reflective as bronze mirrors. (2) The concave side of the disk-shaped bronze implement from Hapsong-ri site was unpolished, and it was different from bronze mirrors. (3) As for the convex sides of the disk-shaped bronze implements, they did not appear to have been polished with care. Considering the above findings, the disk-shaped bronze implements excavated from Goejeong-dong and Tongso-ri sites belong to the stage where they could act as both mirrors and instruments. On the contrary, the disk-shaped bronze implement from Hapsong-ri site can belong to the stage where it lost the function of being a mirror as the result of maintaining only its function as an instrument. Even though disk-shaped implements had two functions, it can be considered that the light reflecting function expanded the role of a mirror with multiple knobs and the sound function helped the engraved round bronze implement to be converted into an eight-armed bronze rattle. Since it has been reported that shamans used bronze mirrors as percussion instruments in their performances in Korean peninsula and Siberia, I propose a reconsideration of the usage of mirrors in the ancient East Asia. Although the essential function of a mirror is to reflect light, other possible usages involving important functions need to be further investigated.

• Annals of Clinical Neurophysiology
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• 제6권1호
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• pp.43-47
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• 2004

We report a case of 36-year-old woman with myasthenia gravis (MG) combined with mediastinal leiomyosarcoma (LMS) and Stevens-Johnson syndrome (SJS). She was admitted to ICU with the symptoms of acute onset headache, diplopia, ptosis, dysphagia, general weakness, and respiratory difficulty for several days. Physical examination revealed tachypnea, decreased breath sounds and dullness to percussion in right lower chest. Neurologic examination showed ptosis, diplopia, decreased gag reflexes, and generalized proximal weakness. Laboratory studies revealed increased serum acetylcholine receptor antibodies and positive Tensilon test. Chest CT showed a huge mass in the right middle mediastium but no evidence of thymic enlargement. Mediastinal LMS was diagnosed by ultrasound-guided needle biopsy. The myasthenic symptoms were fluctuated in spite og intravenous immunoglobulin, plasmapheresis, and corticosteroid. During therapy, SJS developed. She died 4 months after the onset of the myasthenic symptoms despite the chemotherapy for LMS.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.474-478
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• 1992

The non-rational transfer function of a Bernoulli-Euler beam, as an important component of a flexible structure, is analyzed. The true pattern of zeros of that transfer function is investigated as a function of sensor and actuator seperation. Translational displacement sensors are used for two cases in which a force input and a moment input are seperately applied. When the displacement sensor is located at a certain point, the first pair of zeros on the real axis of the s-plane arrive at the origin and cancel the rigid-body mode. The location of the translational displacement sensors on the beamat which the rigid-body mode of the beam is unobservable is analyzed as the center of percussion and is uniquely located for each case. If sensor is moved beyond such a point, a pair of zeros appear on the imaginary axis and move away from the origin along the imaginary axis of the s-plane.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.449-454
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• 2003

The accurate mapping of the basement is one of the most crucial factors in construction of harbour facilities and bridges in the coastal areas. In shallow waters, the seismic reflection method often fails to image the basement geometry beneath the sediment cover in many cases. We present the result of a shallow marine seismic refraction survey using two ships, l2-channel hydrophone arrays deployed on the bottom and a borehole sparker or percussion powder as sources. Velocity structure could be computed by tomography algorithm since more than 6 different source points had been applied for one spread. The comparison of the results of the refraction survey with drilling logs demonstrates remarkable consistency in basement geometry. It thus appears that the refraction method in this study is an efficient and cost-effective way to investigate the basement structure in coastal area, river, and lake.

• Journal of Acupuncture Research
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• 제26권3호
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• pp.19-26
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• 2009

Objectives : The purpose of this study is to introduce oriental medicine music therapy during the acupuncture of pathogenic fire. Methods : We investigated the acupuncture points of pathogenic fire and the methodology of oriental medicine music therapy. Results : During the acupuncture of pathogenic fire, patients listen to proper music and after withdrawing of acupuncture, patients play the musical instrument. The patients with the case of fire due to affection by exopathogen, the method of dispelling superficial fire can be used through playing percussion instruments. The case of patients with the fire of five organ, the Five Phases music can be used properly. Conclusions : This study describes oriental medicine music therapy has a good possibility as a treatment of pathogenic fire with acupuncture.