• 한국콘텐츠학회논문지
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• 제14권9호
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• pp.131-140
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• 2014

본 연구의 목적은 한국무용 동작 시 호흡사용의 숙련도에 따른 운동역학적 분석을 수행하는 것으로 한국무용 중 처용무 낙화유수동작을 실시하게 하였다. 대상자는 호흡사용의 숙련자 5명과 비숙련자 5명으로 선정하였으며 다음과 같은 결과를 도출하였다. 숙련자와 비숙련자의 소요시간은 유의한 차이가 나타나지 않았으며, 신체중심 수직변위는 유의한 차이가 났다(p<.05). 그리고 숙련자와 비숙련자의 신체중심 전 후 속도는 이벤트1과 이벤트4에서 유의한 차이가 나타났고(p<.05), 신체중심 수직속도는 이벤트 3에서 유의한 차이가 나타났다(p<.05). 숙련자와 비 숙련자의 지면반력 성분에서 좌 우 반력은 이벤트2와 이벤트4에서 유의한 차이가 나타났으며(p<.05), 전 후 반력은 이벤트 1과 이벤트5에서 유의한 차이가 나타났다(p<.05). 그리고 수직반력은 이벤트4에서 유의한 차이가 나타났다(p<.05).

• 전기화학회지
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• 제7권2호
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• pp.69-79
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• 2004

전산모사를 이용하여 특성을 정확하게 모사하기 위해서는 전지 내부에서 발생하는 다양한 물리적, 화학적 현상을 고려하여야 한다. 이를 위해, 본 연구에서는 다양한 전지 내부 현상에 대한 변수를 고려할 수 있는 전산유체 상용코드인 CFD-ACE+를 이용하여 평판형 고체산화물 연료전지의 작동 특성을 분석하였다. 단위 스택에서 발생하는 물질전달과 열전달 및 전기화학 반응에 의한 전하이동을 복합적으로 고려하여, 작동조건 하에서 각 공정적, 구조적 변수 변화에 따른 전지특성을 예측하였다. 이러한 전산모사 방법을 통하여 확산과 유동에 의한 전지 내 반응물과 생성물의 mass fraction 분포와 단위 스택의 내부 온도분포 그리고 전지 특성을 나타내는 polarization curve에 의한 고체산화물 연료 전지의 분극 특성을 정성, 정량적으로 제시하였다. 본 연구를 통해 평판형 단위 스택 내에서의 다양한 변수 변화에 따른 전지의 작동 특성에 대한 효율적 예측이 가능하였고, 고체산화물 연료전지 작동 시 발생하는 현상에 대한 전산모사 접근법을 체계적으로 제시할 수 있었다.

• 한국정보통신학회논문지
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• 제11권3호
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• pp.479-485
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• 2007

본 논문에서는 사실적인 질량-스프링 기반 옷감 모델의 애니메이션을 효율적이며 사실적으로 생성하기 위해 근사된 암시적 적분법을 계층적으로 적용하는 기법을 제안한다. 제안된 계층적 시뮬레이션 방법은 매우 많은 정점을 가진 메쉬(mesh)의 사실적인 움직임을 상호작용적으로 생성할 수 있다. 이 기법은 암시적 적분법을 근사하는 빠르고 안정적인 방법을 사용한다. 이 근사 기법은 효율적이기는 하지만 극도로 부정확하며 지나치게 댐핑(damping)이 많이 일어난다. 본 논문에 제안된 계층적 시뮬레이션 기법은 메쉬 구조를 다중 단계로 구성하여 옷감 모델의 사실적인 외형을 표현하도록 하며, 각각의 단계에 시뮬레이션을 적용할 때 현재 단계의 메쉬에 존재하는 일부 질점이 이전 단계의 시뮬레이션 결과를 따르도록 한다. 이러한 계층적 시뮬레이션 방법은 많은 수의 질점으로 구성된 옷감 모델의 사실적인 동작을 효율적으로 생성한다. 또한 계층적 기법은 옷감 모델에 사실적인 주름을 생성할 수 있도록 하며, 계층적 단계에 따라 스프링의 수축 저항을 제어할 수 있도록 하여 주름의 패턴도 쉽게 제어할 수 있도록 한다.

• 한국지반공학회논문집
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• 제23권1호
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• pp.51-65
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• 2007

본 논문의 목적은 초음파 탐사 방법을 이용하여 지반내의 불연속 물질을 탐측할 수 있는 고해상도의 시스템을 개발하고 실내에서 적용하는 것이다. 초음파 탐측 방법은 불연속면의 경계면에서 반사되어온 반사파를 탐측하고, 이를 배열하여 불연속면의 존재를 찾는 방법이다. 본 논문은 암반내 초음파의 전달 양상, 최적화된 트랜스듀서의 선택, 데이터 획득, 신호처리 방법, 영상화 기법, 그리고 실내 적용실험을 포함하고 있다. 실내실험은 수평이동장치와 회전이동장치를 이용하여 수행된다. 수중에서 수평이동 및 회전실험 결과, 불연속면의 위치와 크기가 정확하게 평가 되었다. 또한 석고시료에서 회전실험결과 석고 내에 존재하는 균열과 공동이 비교적 정확하게 영상화됨을 알 수 있다. 본 논문은 새롭게 제시된 방법이 암반 불연속면 탐측에 매우 경제적이고 효과적인 방법이 될 수 있음을 보여준다.

• 한국운동역학회지
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• 제17권1호
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• pp.165-174
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• 2007

The subject of this study was male apparatus gymnastics athlete who had scored high points doing basket with 1/2 turn on parallel bars. Then 3D motion analysis were used to calculate & analyse kinematic variables of Basket with 1/2 turn to Handstand. 1. The total average time spent for Basket with 1/2 turn took $2.16{\pm}.08sec$, at the downward upward phase took $.58{\pm}0.00sec$, $.23{\pm}.00sec$, at flight phase took $.28{\pm}.01sec$, at connected area phase took $.72{\pm}0.21sec$, at rotation area phase took $.35{\pm}.14sec$. To have a successful performance, there should be faster speed and velocity to rotate at the downward upward phase, then the upward velocity and height must be used adequately. Moreover, the speed must be faster at the flight connect phase to stabilize Center of Mass(CM) for the body, and must secure more time at the rotation area to have more stable performance. 2. After handstand on parallel bars while moving CM to right hand side, and It must be performed with big and magnificent performance with putting both hand's center to far away from the parallel bars. 3. Furthermore, CM must be moved fast from downwards to right hand side, and CM must be moved fast in vertical movement at upward and flight phase to avoid CM from moving back and forth, and left and right. 4. At downwards, the subject must rotate as bis as possible using hip-joint as wide as possible and at upwards, must put his body to vertical to have stable performance. While rotating or turning, it is better to do with bigger shoulder angle and have to make sure that trunk angle must be not scattered. To perform better and more positive in basket with 1/2 turn on parallel bars, the centrifugal force must be used big and fast at downward, and at upward and flight phase, downward movement must change to vertical movement as soon as possible while turning movement must happen at handstand position. Time spent must be shorten at connected area to stabilize CM and turning must be natural as possible while securing the necessary time of movement to well-balanced. Also, the body must be vertically closed from the ground.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.833-841
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• 2008

Recently, the upheaval generation in the road which is under service had been reported. Due to the upheaval generation, total 4 lanes were forced to curtail to 3 lanes, and traffic was delayed. In normal situation of cut-slopes in korea, that condition is hard to detect since most cut-slopes contain discontinuous material, that is rock. Common collapses in rock-slopes is wedge failure, plane failure and toppling failure which is all individual mechanism of discontinuous rock mass. In contrast, such upheaval in the road in front of cut-slope can be generated only when circular movement is triggered within the cut-slope. In this sense, rock-slopes barely show any kind of movement in the road locates at the front of them. Numerical analysis is general method in simulation of slope displacement and evaluation of safety. However, numerical analysis programs which are related with rock-slopes are not able to simulate such upheaval movement because that programs are based on discontinuous modeling mechanism. In addition, although numerical analysis programs which are based on FEM/FDM and thus utilize continuous modeling mechanism are able to simulate circular movement and upheaval situation, they have weakness in reflecting discontinuities of rock-slope itself. In this study, detailed in-site investigation and numerical analysis based on in-site condition were performed in order to expect upheaval movement in the road. In this procedure, the FLAC program which uses continuous modeling method was utilized, and new approach reflecting discontinuity developed toward the road with a ubiquitous joint model was tried to derive reliable analysis result.

• 한국지반공학회논문집
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• 제18권5호
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• pp.55-65
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• 2002

소성흐름을 발생시키는 측방유동 가능지반내에 설치된 매설관에 작용하는 토압에 대한 메카니즘을 규명하기 위해 파괴형상실험을 실시하고, 파괴형상실험을 토대로 지반변형속도를 고려하기 위해 Maxwell 점탄성 모델을 적용한 토압산정식을 제안하였다. 직접전단실험으로 구한 점성계수와 내부마찰각과 상재압을 고정하여 이론식으로 도출해낸 점성계수가 잘 일치하고 있음을 확인하였고 모형실험결과와 이론식에 의한 토압은 지반변형속도에 영향을 받으며 비교적 일치하며 지반변형이 없는 경우에도 정지토압을 받음을 알 수 있다. 또한, 지반의 지지력은 점성토에서는 관입전단파괴시의 값과 거의 일치하였다. 또한, 매설관 주변지반의 파괴모드는 매설관직경과 무관하게 지반변형속도에 영향을 받으며 작용토압은 균질한 지층의 경우 선형적으로 증가하고 조립질에 가까울수록 선형적 감소치를 보이므로 매설관주변지반의 매립재를 이용하여 매설관주변의 토압을 경감시킬 수 있음을 알 수 있다.

• 한국운동역학회지
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• 제32권1호
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• pp.24-30
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• 2022

Objective: The purpose of this study was to determine the factors of successful and unsuccessful movements through the analysis of kinematics and muscle activity of the Free Aerial Cartwheel on the balance beam. Method: Subjects (Age: 22.8 ± 2.4 yrs., Height: 158.7 ± 5.0 cm, Body mass: 54.1 ± 6.4 kg, Career: 13 ± 2.4 yrs.) who were currently active as female gymnasts participated in the study. They had no history of surgical treatment within 3 months. Subject criteria included more than 10 years of professional experience in college and professional level of gymnastics and the ability to conduct the Free Aerial Cartwheel on the Balance Beam. Each subject performed 10 times of Free Aerial Cartwheel on the balance beam. One successful trial and one unsuccessful trial (failure) among 10 trials were selected for the comparison. Results: It was found that longer time required in case of unsuccessful trial when performing the Free Aerial Cartwheel on the balance beam compared with successful trial. It is expected to be the result of movement in the last landing section (i.e. phase 5). In addition, it was found that the center of gravity of the body descends at a high speed to perform the jump (i.e. phase 2) in order to obtain a sufficient jumping height when the movement is successful while the knee joint is rapidly extended to perform a jump when movement fails. In the single landing section after the jump (i.e. phase 4), if the ankle joint rapidly dorsiflexed after take-off and the hip joint rapidly flexed, so landing was not successful. Conversely, in a successful landing movement, muscle activity of the biceps femoris was greatly activated resulting no shaking in the last landing section (i.e. phase 5). Conclusion: In order to succeed in this movement, it is necessary to perform a strong jump after rapidly descending the center of gravity of the body using the force of the biceps femoris muscle. Further improvement of the skills on the balance beam requires the analysis of the game-like situation with continuous research on kinematic and kinematic analysis of various techniques, jumps, turns, etc.

• 한국운동역학회지
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• 제21권4호
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• pp.391-395
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• 2011

To investigate the anticipatory effect on landing patterns during side-cutting maneuver, thirteen healthy female elite college soccer players participated in this study. Three-dimensional knee kinematics, effective mass and correlation between both these were measured and analyzed using a motion analysis and force plates. Each testing session included anticipated tasks, $45^{\circ}$ side-cutting tasks (AC), followed by a set of unexpected side-cutting (UC) in a random order. Knee flexion/extension, valgus/varus and internal/external rotation angles and effect mass were compared by using paired t-test. Also, correlation analysis was performed to identify the relationship between knee angles and effective mass. Effective mass during UC was greater than that during AC. Effective mass and maximum knee flexion angle were positively correlated during AC and not during UC. Based on the relationship between effective mass and knee flexion angle in AC, shock absorption can be controlled by knee joint flexion in pre-predicted movement condition. However, effective mass can not be controlled by knee flexion in UC condition. The unexpected load affects were more irregular on the knee joint, which may be one of the injury mechanisms of anterior cruciate ligament (ACL) in female soccer players.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제40권
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• pp.19.1-19.6
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• 2018

Background: Calcium pyrophosphate dihydrate deposition disease (CPDD) is a rare disease in the temporomandibular joint (TMJ) space. It forms a calcified crystal mass and induces a limitation of joint movement. Case presentation: The calcified mass in our case was occupied in the left TMJ area and extended to the infratemporal and middle cranial fossa. For a complete excision of this mass, we performed a vertical ramus osteotomy and resected the mass around the mandibular condyle. The calcified mass in the infratemporal fossa was carefully excised, and the segmented mandible was anatomically repositioned. Scanning electronic microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDS) microanalysis was performed to evaluate the calcified mass. The result of SEM/EDS showed that the crystal mass was completely composed of calcium pyrophosphate dihydrate. This result strongly suggested that the calcified mass was CPDD in the TMJ area. Conclusions: CPDD in the TMJ is a rare disease and is difficult to differentially diagnose from other neoplasms. A histological examination and quantitative microanalysis are required to confirm the diagnosis. In our patient, CPDD in the TMJ was successfully removed via the extracorporeal approach. SEM/EDS microanalysis was used for the differential diagnosis.