• 한국구조물진단유지관리공학회 논문집
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• 제23권4호
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• pp.86-95
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• 2019

탄소섬유는 경량이면서 높은 기계적 특성 때문에 우주항공, 선박, 자동차, 토목 및 건축과 같은 산업분야에서 그 어느 때 보다 더 광범위하게 적용되고 있다. 본 연구는 섬유혼입률 및 섬유길이 변화에 따른 탄소섬유 보강시멘트 복합재료( CFRC)의 역학적 특성과 휨 거동을 분석하였으며, 또한 자연 낙하시험에 의한 모르타르 시편에 대한 내충격성을 비교, 검토하였다. 더불어, 탄소섬유(CF)의 혼입률은 0.5%, 1.0%, 2.0% 및 3.0%로 변화를 주었으며, 각각의 섬유길이는 6 mm와 12 mm를 사용 하였다. 실험결과, 플로우 값은 탄소섬유의 뭉침현상으로 인해 유동성 측면에서 매우 불리하였으며, 단위용적질량은 다소 감소하였다. 특히, 압축강도는 탄소섬유 혼입량이 증가함에 따라 감소하는 것으로 나타내었다. 반면 휨 강도는 섬유 길이가 12 mm이고 2% 혼입한 것이 가장 높은 휨 강도를 보였다. 내충격성 시험결과, 보통 모르타르 시편은 완전파괴까지의 낙하횟수가 2~3회 정도 걸리지만 반면 CFRC 시편은 섬유혼입량이 증가함에 따라 다소 차이가 있지만, 섬유길이가 12 mm이고 섬유혼입량 2% 인 경우 충격에 대한 저항성이 가장 높았다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.347-351
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• 2004

[ $Si_3N_4$ ] composites have been extensively studied for engineering ceramics, because it has excellent room and high temperature strength, wear resistance properties, good resistance to oxidation, and good thermal and chemical stability. In the present work, carbon short fiber reinforced $Si_3N_4$ ceramics were fabricated by hot press method in $N_2$ atmosphere at $1800^{\circ}C$ using $Al_2O_3\;and\;Y_2O_3$ as sintering additives. Content of carbon short fiber was $0\%,\;0.1\%\;and\;0.3\%$. The composites were evaluated in terms of density, flexural strength and elastic modulus through the 3-point bending test at room temperature. Also, The wear behavior was determined by the pin on disk wear tester using silicon nitride ball. Experimental density and flexural strength decreased with increasing content of carbon fiber. But specific modulus increased with increasing content of carbon fiber. In addition, friction coefficient and specific wear loss decreased with increasing content of carbon short fiber by reason of interfacial defects between matrix and fiber.

• 대한통합의학회지
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• 제3권4호
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• pp.37-42
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• 2015

Purpose: This study was conducted to test the impact of The Dynamic Visual-Motor integration training has effect on the visual perception reaction velocity. Dynavision were used to measure data from the participating 24 students(K college). Method : The participants were the 24 students of 'K' College in Busan in there twenties. They were divided into the The Dynamic Visual-Motor integration training group and the control group. To know if the Dynamic Visual-Motor integration training has effect on the visual perception reaction velocity, the Dynamic Visual-Motor integration training was implemented triweekly for 4 weeks. In Dynamic Visual-Motor integration training the ball should be grasped with one hand and threw by an arm. Only the balls threw beyond the objective point were counted. The visual perception reaction velocity and the number of response were measured before and after experiment by Dynavision. Result : Firstly, the visual perception reaction velocity was increased in Dynamic Visual-Motor integration training group compared with control group. Secondly, the number of response was also increased in Dynamic Visual-Motor integration training group compared with control group. Conclusion : As a result of The Dynamic Visual-Motor integration training has an effect on the visual perception reaction velocity and the number of response. The Dynamic Visual-Motor integration training seems to be effective for cerebral apoplexy patient who has visual perceptional disability or cerebral palsy child in training for visual perceptional development or daily living activities development. Study participated by more detailed and practical patients in hospital is needed.

• 반도체디스플레이기술학회지
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• 제15권4호
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• pp.10-15
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• 2016

In this paper, novel ball grid array (BGA) interconnection process using solderable anisotropic conductive adhesives (SACAs) with low-melting-point alloy (LMPA) fillers have been developed to enhance the processability in the conventional capillary underfill technique and to overcome the limitations in the no-flow underfill technique. To confirm the feasibility of the proposed technique, BGA interconnection test was performed using two types of SACA with different LMPA concentration (0 and 4 vol%). After the interconnection process, the interconnection characteristics such as morphology of conduction path and electrical properties of BGA assemblies were inspected and compared. The results indicated that BGA assemblies using SACA without LMPA fillers showed weak conduction path formation such as solder bump loss or short circuit formation because of the expansion of air bubbles within the interconnection area due to the relatively high reflow peak temperature. Meanwhile, assemblies using SACA with 4 vol% LMPAs showed stable metallurgical interconnection formation and electrical resistance due to the favorable selective wetting behavior of molten LMPAs for the solder bump and Cu metallization.

• Korean Journal of Acupuncture
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• 제26권2호
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• pp.75-89
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• 2009

Objectives: Warm needling combines simultaneously the effects of acupuncture and moxibustion. This study was to investigate whether warm needling could relieve acute knee arthritis induced by carrageenan in rats. Methods: To illuminate the underlying mechanisms of the warm needling-induced antinociception, weight bearing force (WBF) was observed on the acute knee arthritic rat model. Under general anesthesia, ST36, SP9, Hakjung extra point, LI4 were punctured and stimulated with 30 mg moxa ball combustion on top of the needle (${\emptyset}0.18{\times}8mm$). Results: In behavioral test, rats subsequently showed a reduced stepping force of the affected limb 3 hours after the induction of arthritis. Warm needling on the contralateral or ipsilateral ST36 failed to show antinociceptive effect on the acute knee arthritis. Warm needling on the contralateral SP9 or LI4 increased WBF values to normal level in the acute stage of the arthritis. Warm needling on the Hakjung extra-point resulted in the significant antinociceptive effects through acute stage. These effects of warm needling were suppressed by opioids receptor antagonist naltrexone (10 mg/kg, i.p.) and alpha adrenoceptor antagonist phentolamine (5 mg/kg, i.p.). Conclusion: The data suggest that warm needling-induced antinociception is differently mediated by acupoints and accomplished by activating the descending inhibitory systems including endogenous opioids and $\alpha$-adrenoceptors.

• 대한의용생체공학회:의공학회지
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• 제43권5호
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• pp.361-368
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• 2022

The purpose of this study was to develop a hand rehabilitation training system for hemiplegic patients. We also tried to find out five hand postures (WF: Wrist Flexion, WE: Wrist Extension, BG: Ball Grip, HG: Hook Grip, RE: Rest) in real-time using multi-channel EMG-based deep learning. We performed a pre-processing method that converts to Spider Chart image data for the classification of hand movement from five test subjects (total 1,500 data sets) using Convolution Neural Networks (CNN) deep learning with an 8-channel armband. As a result of this study, the recognition accuracy was 92% for WF, 94% for WE, 76% for BG, 82% for HG, and 88% for RE. Also, ten physical therapists participated for the usability evaluation. The questionnaire consisted of 7 items of acceptance, interest, and satisfaction, and the mean and standard deviation were calculated by dividing each into a 5-point scale. As a result, high scores were obtained in immersion and interest in game (4.6±0.43), convenience of the device (4.9±0.30), and satisfaction after treatment (4.1±0.48). On the other hand, Conformity of intention for treatment (3.90±0.49) was relatively low. This is thought to be because the game play may be difficult depending on the degree of spasticity of the hemiplegic patient, and compensation may occur in patient with weakened target muscles. Therefore, it is necessary to develop a rehabilitation program suitable for the degree of disability of the patient.

• 대한간호학회지
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• 제29권2호
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• pp.258-270
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• 1999

This study was carried out to offer the basic data for more qualitative lives of the middle-aged women through their health maintenance and control. So, the researcher reviewed and analyzed the health problems of the middle-aged women, the differences of main symptoms in each subject, positive ratcs in screening tests, the difference of screening tests with age and the correlation of obesity and blood pressure with screening tests. All subjects were 218 women(40-59years) who had a check-up at a comprehensive health check-up center in K University Hospital in Seoul from July 1, 1998 to August 31. 1998. Questionaires were developed to get subjects, general characteristics. main symptoms, medical examination and diagnosed disease by the researcher referring through the questionaires of comprehensive health check-up center and the medical recorders were used as a tool of study. The researcher analyzed the data with SPSS PC+ ; the distribution of the subjects, general characteristics and main symptoms with percentage : the difference between main symptoms and screening tests with X$^2$-test, ANOVA. The results are as follows. 1) Among the age distribution, most were 40-45 years old and unemployed. 2) The most common complaints were indigestion in digestive system, cough in respiratory system, heart beat in cardiovascular system, general sweat in endocrine system. edema in urinary system, easy bruise in hematologic system, backache in musculoskeletal system, headache in psychoneurologic system, lochia in gynecology, itch in dermatology system, eye ball pain in visual system and tinnitus in auditory system. 3) In main symptoms according to age, the 40-45 age group had a higher rate of complaints in digestive system and gynecology than other age group ; the 46-49 age group in endocrine system. 4) The main symptoms according to diagnosis had no difference statistically. 5) The screening tests which showed high rates of abnormality were mammography(the highest), abdominal ultrasonography, upper gastrointestinal series/gastrofiberscopy, PFT. In all age group the highest rate of abnormality was seen in mammography. 6) In screening tests according to age. the 46-49 age group showed higher positive rates of pap smear, blood sugar test, urine test than any other age group ; the 50-55 age group showerd higher positive rates of obesity, BP, chest X-ray, abdominal ultrasonography, ESR, SGOT, CRP and urine micro. 7) In correlation of obesity with screening test, the obesity group showed higher positive rates of blood pressure, chest X-ray, abdominal ultrasonography, HCT and CRP than the normal weight group. 8) In correlation of blood pressure with screening test, the hypertension group showed higher positive rate of obesity, chest X-ray, abdominal ultrasonography, pap smear and blood sugar than the normal blood pressure group. In conculusion, the middle-aged women have various physical symptoms and affected by age. The obesity and BP have an important effect on the health of the middle aged women. Therefore, this study is considered significant as data for qualitative lives of the middle-aged women playing an important part of family health care by catching of their health problem complaints for prevention of disease and promotion of health.

• 한국산학기술학회논문지
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• 제19권9호
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• pp.384-390
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• 2018

기후변화와 도시화에 따른 오염으로 인하여 대기 및 토양이 오염되었고, 이들 오염물질이 점오염원과 비점오염원을 통하여 수질 내로 흘러 들어가면서 수질오염이 심각한 수준에 이르렀다. 이러한 수질 내 생물학적 오염원 제거를 위하여 간편하면서도 효율이 높은 수질 정화용 필터의 개발이 요구되는 실정이며, 이를 위하여 항균력을 가지고 있는 구리를 이용하여 연구를 진행하였다. 본 연구에서는 수질오염의 기준으로 사용되는 대장균 외 주요 병원성 균 4종 (Bacillus subtilis, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa)을 사용하였으며, 스트립 형태의 구리선 0.5g, 1g, 2g을 이용하여 직경 2cm의 구 형태로 제작하였다. 항균력 확인을 위하여 각 병원성 균을 접종한 후 구리공을 장착한 다음, 99% 이상의 항균력을 가지는 조건을 조사하였다. 연구 결과 0.5g의 구리선으로 만든 구리 공을 최소 20분간 반응시켰을 때 5종의 병원성균에 대해서 99% 이상의 생장 억제능이 나타나는 것을 확인하였다. 본 연구 결과를 바탕으로 세포 실험 등의 추가 실험이 진행된다면 수질 정화용 필터로 사용되기에 충분할 것으로 판단되며, 이를 통해 공장 및 도시 폐수 뿐만 아니라 축산 및 양식 산업 분야에 광범위하게 적용될 수 있을 것으로 기대된다.

• Journal of Periodontal and Implant Science
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• 제36권2호
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• pp.461-471
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• 2006

In order to achieve a satisfactory esthetic result of periodontal surgery or implant in maxillary anterior area, periodontists must be aware of normal alveolar bone anatomy. The purpose of this study was to evaluate the relationship of alveolar bone morphology to tooth shape and form. 78(mean age : 25 yrs) periodontally healthy volunteers participated in this study. Two maxillary central incisor and one lateral incisor were selected to study. With minimal local anesthesia, gutta-percha cone inserted to labial gingival sulcus of selected teeth just after bone sounding with periodontal probe. Metal ball (4mm diameter) attached to palatal fossa of central incisor. Then, periapical radiograph was taken according to long cone paralleling technique. After film scan, labial alveolar bone profile reproduced along interproximal bone and apical ends of gutta-percha cones on computer screen. By utilizing computer program, the distance from height of interproximal bone to the labial bone crest in central incisor-central incisor and central incisor-lateral incisor area was measured and converted to real distance by using vertical length of metal ball on film. After measuring crown length & width of central incisor, the 10 individuals ranked lowest GW/L ratio (crown width/length ratio) and the 10 ranked highest were selected as having a long-narrow(group N), or a short-wide(group W) form of the central incisors. Means of the distance from height of interproximal bone to the labial bone crest of group N, W were calculated and compared by means of independent t-test. The results were as follows: 1. Mean distance from the height of the interproximal bone to the labial bone crest was $3.5{\pm}0.7mm$ between two central incisor, and $2.8{\pm}0.6mm$ between central and lateral incisor. 2. Mean GW/L ratio of group N was 0.57, and group W was 0.8. Mean distance from the height of the interproximal bone to the labial bone crest of group N was higher than group W in both measured area(measurements of group N, W were $3.9{\pm0.2mm$ and $3.5{\pm}0.2mm$ between two central incisor, $3.0{\pm}0.2mm$ and $2.8{\pm}0.2mm$ between central and lateral incisor), but there were no statistically significant differences when the groups were compared. Within the limits of the present study, there was a tendency that subjects with long-narrow teeth have more scalloped alveolar bone profile than subjects with short-wide teeth in upper anterior area, but no statistically significant differences were found.

• 한국세라믹학회지
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• 제36권2호
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• pp.178-185
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• 1999

Si3N4 겔캐스팅공정 제어를 위하여, 슬립 조성의 영향이 슬립의 점성특성과 성형체의 기계적 특성 및 소결체의 밀도에 미치는 영향에 대하여 조사하였다. 아크릴아마이드 모노머, 고분자전해질, 그리고 질화규소의 혼합물을 어트리터에 예비혼합한 후 볼밀링하여 슬립을 제조하였다. 개시제가 혼합된 슬립을 진공탈포하고 몰드에 주입하고 중합을 진행하였으며, 겔화된 슬립을 건조하여 성형체를 얻었다. 슬립의 특성과 성형체의 기계적 특성을 평가하기 위해, 슬립의 점도 측정과 직경방향 압축시험을 행하였다. 그 결과, near net shaping을 위한 낮은 점도를 갖는 46 vol%의 고농도 질화규소 슬립의 제조가 가능하였다. 성형체가 기계적 특성은 주로 모노머의 농도에 비례하여 증가하였다. 또한, 겔캐스트 성형체의 인장강도가 약 3MPa이 넘으면 기계적 가공이 가능하였으며, 겔캐스팅 성형체를 176$0^{\circ}C$, 3시간 상압소결하여 약 98.5%의 상대밀도를 얻을 수 있었다.