• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1996.04a
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• pp.376-383
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• 1996

보(beam)는 기계 구조 및 항공 우주 구조물의 기본적인 요소로서, 특히 큰 동적 거동을 하는 경우는 비선형성이 두드러지게 나타나는 것으로 알려져 있고[4], 헬리콥터의 회전날개(rotor blade)나 두께가 얇은 고속회전 축등의 경우에는 비틀림(torsion)과 굽힘(bending) 운동이 비선형 연성되어 나타나게 된다. 이러한 비선형 연성 효과를 갖는 경우에는 운동의 양상이 복잡하게 전개된다. 따라서 본 연구에서는 비선형 연성운동이 생기는 이러한 단순 외팔보에 대해 비선형 진동 특성을 파악하고 각 비틀림(internal resonance)현상[5]에 따른 정상상태 진폭 응답의 해석을 그 목적으로 한다.

• Proceedings of the KSLP Conference
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• 1997.11a
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• pp.265-265
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• 1997

음성이란 성대내근과 성대외근의 운동에 의해 진성대에서 규칙적이고 조화로운 진동이 이루어져 나타나는 것으로, 이러한 운동 등에 이상이 생기거나 진성대에 기질적인 변화가 왔을 때 음성이 변하게 된다. 그러나 이런 환자들의 진단을 위하여 후두소견을 관찰해 보면 진성대 뿐만 아니라, 상후두에서도 여러 가지 양상의 다른 움직임을 확인할 수가 있는데, 상후두는 진성대와는 달리 특별한 자체를 움직일 만한 근육들이 발달되어 있지 않은 구조물임에도 불구하고 여러 다른 발성에 따라 다양한 움직임을 나타내게 된다. 이러한 것들은 진성대와 연결되어 있는 성대내근이나 후두의 외부에 붙어있는 성대외근의 영향에 의해 나타날 수가 있다고 생각이 되고, 이러한 것들은 일차적으로 또는 이차적으로 성대의 진동에 영향을 줄 수 있을 것으로 생각된다. 이에 저자들은 발성시 상후두의 움직임과 성대외근과의 관계를 확인하기 위하여 상후두의 움직임을 여러 가지 모양으로 만들도록 훈련한 후 스트로보스 3102;을 이용하여 상후두의 움직임을 확인하면서, 각각의 경우에 따라 근육의 수축정도를 비교할 수 있고 비침습적인 표면전극을 이용한 근전도 검사를 시행하여 이들에 관한 연구를 하였다.다.

• The Journal of the Korea Contents Association
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• v.9 no.1
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• pp.348-358
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• 2009

Diffuse axonal injury(DAI) is a common form of traumatic brain injury and thought to be a major contributor to cognitive dysfunction. Physical activity has been shown to beneficial effects on physical health and influences in hippocampus which is an important location for memory and learning. The purpose of this study was to investigate the effect of motor training on motor performance and axonal regeneration in hippocampus through the immunoreactivity of GAP-43 after diffuse axonal injury in the rats. The experimental groups were applied motor training(beam-walking, rotarod, and Morris water maze) but control groups were not. The time performing the motor tasks and GAP-43 immunohistochemistry were used for the result of axonal recovery. There were meaningful differences between experimental groups and control groups on motor performance and GAP-43 immunohistochemistry. The control groups showed increasing tendency with the lapse of time, but experimental groups showed higher. Therefore, Motor training after DAI improve motor outcomes which are associated with dynamically altered immunoreactivity of GAP-43 in axonal injury regions, particularly hippocampus, and that is related with axonal regeneration.

• Journal of Biomedical Engineering Research
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• v.21 no.4
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• pp.339-344
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• 2000

The mucociliary system is one of the most important airway defense mechanisms in human body and impairment of ciliary movement results in various diseases in respiratory tract. In this study, we have developed a system that can measure ciliary movement in vivo and quantified ciliary beat frequency (CBF) through autoregressive (AR) power spectrum. To measure the frequency in vivo, we applied a photoelectric method that was composed of a laser light and a fiber optic probe. Scattered signals are transferred to a PC in which they are displayed on the monitor and its CBF is determined by the AR method in were acquired. For 8 normal subjects, the analyzed CBFs ranged from 5 to 10Hz and its mean was 7.3${\pm}$1.1Hz. This result showed similar aspects to the reported results of CBFs to data. We expect that this result will be applied in various clinical studies such as analysis of CBF changes by drugs or by diseaes.

• Journal of the Korean Arthroscopy Society
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• v.12 no.1
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• pp.24-31
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• 2008

Purpose: We purposed to analyze the incidence and the patterns of the injuries associated with anterior cruciate ligament(ACL) tears. Materials and Methods: We retrospectively reviewed 547 knees that had undergone ACL reconstructions and compared the associated injuries according to the time of injury(acute vs. chronic), the cause of injury(sports vs. non-sports) and the type of sports. Results: Medial collateral ligament(MCL) injury and bone contusion were more in acute injury group less than 3 months after trauma(p=0.001, 0.019) and the injuries of medial or lateral meniscus were more in chronic injury group more than 3 months after trauma(p=0.014, 0.029). The trochlea in acute injury group(p=0.027) and the medial femoral condyle in chronic injury group(p=0.011) had higher incidence of chondral injury. Grade I, II chondral injury was frequent in acute injury group(p=0.016) and grade III, IV chondral injury was frequent in chronic injury group(p=0.017). Lateral meniscus injury was frequent in sports injury group(P=0.035). Medial collateral ligament injury was frequent in ski(P=0.005), and chondral injury was in gymnastics(P=0.017). Conclusions: The incidences of medial and lateral meniscus tears and grade III, IV chondral defects were high in chronic injury group. According to the causes of the tears and the types of sports, some differences in the incidence and pattern of associated injuries were found.

• The Journal of Korean Academy of Prosthodontics
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• v.51 no.3
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• pp.199-207
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• 2013

Purpose: The importance of occlusal contacts of the natural dentition for durability of teeth, mandibular stabilization, and restorative dentistry is well known. The purpose of this study is to analyze the occlusal contact and guidance pattern of Koreans by evaluating the static occlusion on maximal intercuspal position and measuring dynamic occlusion during straight protrusion. Materials and methods: The occlusal contacts at maximal interincisal position and the occlusal guidance pattern during straight protrusion of 29 subjects were recorded with shimstock foil (Whaledent, Langenau, Germany), T-Scan III (Tekscan Inc., Boston, MA, USA), polyvinylsiloxane registration material (Genie Bite, Sultan Healthcare, Hackensack, NJ, USA) and compared. Occlusal registration procedures were repeated 3 times. The position was fixed to an upright position and the head position was fixed with the Frankfurt horizontal plane paralleling the horizontal plane. Fisher's Exact Test (R-General Public License, ver. 2.14.1) and Pearson's Test were used to assess the significance level of the differences between the experimental groups (${\alpha}=.05$). Results: When using shimstock foil, T-Scan III system, and polyvinylsiloxane registration material, most of the patients showed contact on anterior, premolar, and molar teeth during maximal intercuspal position. Approximately 51% of maximal intercuspal position showed anterior contact using shimstock foil. When examining the protrusive movement using shimstock foil and T-Scan III system, guidance pattern with the central incisor was the most common. Conclusion: During maximal intercuspal position, there were cases in which not all of the teeth showed occlusal contact. During mandibular protrusive movements, one or more maxillary central incisors frequently joined in straight protrusion and the posterior teeth were disoccluded. Therefore, the anterior teeth protect the posterior teeth, and vice versa. Thus, mutually protected occlusion should be applied when reconstructing occlusion.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.4 no.1
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• pp.98-105
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• 1993

Objective ' The purpose of this study was to investigate the behavioral characteristics of children with allergic disease Method : In a population of 80 children who were registered at a pediatric allergic clinic in Kangnam St Mary's hospital, parents completed a standardized child behavior checklist (CBCL) to evaluate their children Clinical factors associated with allergy were examined in relation to the rated scores of CBCL Results : Allergic children were rated significantly more aggressive and delinquent, and less withdrawned on the CBCL rating when compared to the age- and sex-matched normal control children. Within the allergic population, children who had family history of allergic disease had higher scores of CBCL in hyperactivity and aggressive behavior than the children without family history. Conclusion : The results were discussed with the respect to familial traits of allergy and temperament as risk factors for the emergence of behavior problems in childhood allergy

• The Journal of Engineering Geology
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• v.8 no.1
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• pp.35-49
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• 1998

To interpret the movement historv of the Yangsan fault, the paleostresses were analyzed from about 1,000 striated small faults and 330 extension joints which were measured from 37 sites near and along the strike of the Yangsan fault from Yangsan-si, Kyeongsangnam-do to the Shinkwang-myeon, Kyeongsangbuk-do. Six sequential tectonic events have boen established as followings: (I) NW-SE extension, (Il) ENE-WSW compression and NNW-SSE extension, (III) NW-SE compression, (W) ENE-WSW extension, (V) E-W comoression and N-S extension, and (VI) NNE-SSW compression and(VI) NNE-SSWextension. The movement history of the Yangsan fault rnrning in NNE direction were inteepreted based on these six sequential stress fields. The initial feature of the Yangsan fault was formed at the first stage with the development of extension fractures by tectonic event (I) of NW-SE extension. The fault was acted continuously with a right-1ateral strike-slip movement by tectonic event( II) closely related to event( I). The movements had been continued until the Late Miocene. This age was the most active period in faulting. The left-lateral strike-slip movement was followed by subsequent tectonic events (ffi) and (IV). The activity of the Yangsan fault was suspended temporarily by compression of tectonic event (V) which was perpendicular to the strike of the fault. This period might be very short and the magnitude of the tectonic was also small. In the last stage, the fault acted with slight extension or right-lateral moveenent by tectonic event (VI).

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.2
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• pp.269-280
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• 1995

저작은 교합과 악운동 뿐만 아리라 근신경계, 고위 중추까지 복합적으로 관여하는 기능적 행위이다. 교합 양상은 다양하게 저작 형태에 영향을 끼치며 저작 효율에도 관여한다. 저작 형태는 다양한 모양을 가지나 두가지 전형적인 군 즉, 전방에서 관찰시 그 양상이 수직적이며 chopping운동을 닮은 군과 저작 형태가 주로 측방으로 이루어지며 grinding을 하는 군으로 나눌 수 있다. 본 연구의 목적은 저작 형태의 치아가 교합접촉 및 저작 효율에 미치는 영향을 고찰해 보고자 하는 것이다. 하악운동궤적기록기를 이용하여 정상교합을 가진 치과대학생중 전형적인 2가지 저작형태를 보이는 각 10명씩을 피검자로 선택하였다. 3가지 하악위 즉, 중심위, 작업측 비작업측에서의 교합접촉을 고무형 교합인기재로 기록하여 천공부의 직경이 1mm이하면 1점, 1-2mm또는 직선상이면 2점, 2mm이상이면 3점으로 평가하여 각 점수의 합으로 좌우 소구치 및 대구치의 접촉 지수를 측정하였다. 저작 효율을 평가하기 위해 땅콩 3g(${\pm}0.01g$)을 20회 저작하게 한 후 3회 입을 헹구어 뱉게 하였다. 체눈 크기가 각 0.425, 0.60, 0.85, 2.0, 4.0인 체에 거른 후 $65^{\circ}C$로 오븐에서 세시간 말려 무게를 측정하고 중심 크기$(M_{50})$과 저작효율치(R)를 계산 비교하여 다음과 같은 결론을 얻었다. 1. Chopping형은 grinding형에 비해 중심위에서 더 넓은 교합접촉을 보였다(P<0.01). 2. Grinding형은 chopping형에 비해 측방위에서 더 넓은 교합접촉을 보였다(P<0.01). 3. Chopping형은 중심크기($(M_{50})$)과 저작효율치(R)로 비교하였을 때 더 좋은 저작 효율을 보였다(P<0.01).

• Korean Journal of Cognitive Science
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• v.18 no.4
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• pp.325-350
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• 2007

This study investigated global and local characteristics of eye movement while 16 college students read 48 easy Korean sentences. It was found that readers lusted for about 225ms at the word cluster(eojeol), made a forward saccade of about 3.6 characters to the next word, skipped short and high-frequent words about 25% during the first-pass reading, and regressed backward at 19%. There were also individual differences in readers' pattern of fixation and saccade. In addition, the effects of word cluster length and word frequency and the effects related to landing position were examined. The eyes landed on the center of a word cluster more frequently than on the boundaries. When the eyes landed at the boundaries, the eyes fixated the word cluster again more frequently. The word clusters with high-frequency words were read faster than those with low-frequency words.