• 한국가구학회지
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• 제20권6호
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• pp.599-604
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• 2009

For the search of unified law of moisture movement in wood, moisture distribution of Korean red pine at non-steady state was investigated. We assume that the equilibrium moisture content (EMC) in wood depends on only temperature and relative humidity, it can be control in temperature and humidity chamber. If temperature is constant and humidity or vapor pressure is changed with sin curve shape at adequate cycles, EMC in chamber can be changed as well with sin-curve shape. The setup condition of a non-steady state in humidity control chambers is a constant temperature at $20^{\circ}C$ and 15+10 sin ${\omega}t$ percent EMC. It can be found that the distribution of moisture in the specimen with varying relative humidity are illustrated various types. Moisture in wood is complicated and vibrates with the moisture sorption process. Considering a unified law of moisture movement in wood, it is considered that the most important fact is to search the method of precise diffusion & transfer coefficients.

• 한국해안해양공학회지
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• 제10권4호
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• pp.165-173
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• 1998

파고와 주기 그리고 수심의 함수로 정의된 이류계수를 파고와 주기에 대한 결합분포함수와 확률적으로 결합하여 수중둔덕의 이동율을 예측할 수 있는 해석해를 유도하였다. 파랑의 비선형성에 의하여 유발되는 하상에서의 흐름이 표사의 이동을 유발한다는 가정하에 개념적 모형의 표사이동량 방정식을 사용하였다. 표사보존식에 표사이동량을 대입하여 시간에 따른 해저면의 변동을 나타내는 비선형 이류-확산 방정식을 얻을 수 있었다. 해석해에 의하면 수심이 증가할 수록 수중둔덕의 이동율은 지수적으로 감소하는 경향을 보였다. 그러나 스펙트럼에서 주파수 영역의 폭을 정의하는 계수, v의 값이 커지면 수중둔덕의 이동율은 증가하였다. 해석해에 의하여 예측된 수중둔덕의 이동율은 관측자료보다 과대평가하는 경향을 나타내나, 해석해를 유도하는 과정에 내포된 이론식의 제약성 및 입력자료의 부정확성 등을 고려할 때 전반적으로 해석해의 결과는 관측자료와 잘\ulcorner 일치한다고 볼 수 있다. 특히, 수심의 변화에 따른 해석해의 거동은 대상영역 외해에서 추정된 자료를 이용하여 이산화 기법으로 추정된 결과와 매우 잘 일치하였다.

• 한국지반공학회지:지반
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• 제5권1호
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• pp.47-60
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• 1989

본 논문에서는 사질토를 뒷채움한 강성연직벽에 작용하는 횡토려의 분포를 유한요소법을 이용한 탄소성해석에 의하여 구하고 벽체의 3가지 변위형태(벽체정부중심회전, 벽체양부중심회전및 평행이 동형태 및 변위의 크기가 토압분포에 미치는 영향을 연구하였다. 그리고 이들 토압을 Rankine주동 토압 및 Dubrova주동토압과 비교하였다. 벽달정부중심회전하는 경우 아아칭효과에 의하여 역5-형토려분포를 나타내고 결과적으로 벽체 전 높이에 작용하는 총토추의 작용점은 벽체람부로부터 벽체높이의 113보다 훨씬 높을 뿐만 아니라 다 른 형태의 벽체변위에 비하여 제일 높고 또한 크기도 가장 크다. 그리고 벽체변위가 증가하여 주동상태로 파괴될 때 뒷채움지반내에 발달하는 소성영역은 벽체저부중심회전형태인 경우에만 쐐기형태로 발달하고 다른 변위형태의 경우에는 쐐기형태를 보이지 않는다. 또한 뒷채움이 경사지면인 경우 몇가지 경사도에 대한 저부중심회전벽체의 토압분포를 나타내었다.

• 대한치과교정학회지
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• 제31권3호
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• pp.325-333
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• 2001

바람직한 교정치료는 최적의 교정력을 치아에 가하여 정확하게 치아이동을 조절하고 예측함에 따라 가능해진다. 치관에 힘과 모멘트가 동시에 적용될 때 그 비율(M/F ratio)에 따라 치주인대에 나타나는 응력 분포가 변화하게 되고 이에 따른 회전중심의 위치가 변하게 되는데 이런 양상을 파악함으로써 정확한 치아이동을 조절하고 예측할 수 있다. 본 연구에서는 교정력에 따른 치주인대 및 치조골 부위에서의 응력 분포를 알아보기 위하여 상악 중절치 치근 8부위에 스트레인 게이지를 부착한 인공 치아를 광탄성 레진에 매식한 4mm 정중이개 증례의 상악 전치부 실험모형을 제작하여 응력 분포를 조사하였다. 폐쇄 방법으로 다음과 같은 3가지 방법을 적용하였다. 1. 금속 호선의 삽입 없이 100g의 힘을 발휘하는 elastomeric chain만 사용한 경우, 2. .016" 금속호선을 삽입하고 elastomeric chain을 사용한 경우, 3. .016“x.022” 금속호선을 삽입하고 elastomeric chain을 사용한 경우. 각각의 경우에서 치근의 근심면, 원심면 및 순면, 설면에 나타나는 응력을 계측하여 비교 분석한 결과 다음과 같은 결론을 얻었다. 1. 치근 부착 스트레인 게이지를 이용한 응력 분포 조사 방법으로 치아이동시 치근의 근 원심면 및 순 설면에서의 응력 분포를 파악할 수 있었으며 이에 따른 모멘트 팔의 형성을 추정함으로써 치아의 회전양상을 알 수 있었다. 2. 호선없이 교정력을 적용한 경우 정출 및 경사이동이 컸으며 호선 적용에 따라 압하 및 치체이동 양상을 보이는 것을 응력 분포 파악을 통해 확인할 수 있었다.

• 대한치과교정학회지
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• 제21권3호
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• pp.617-634
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• 1991

The retraction of anterior teeth is one of the fundamental methods in orthodontic treatment and a proper position and angulation of anterior teeth after the retraction are very important for esthetics, stability, and function of teeth. In this research we analyzed, by Finite Element Method, the stress distribution on the periodontal ligament according to the variation of force and moment applied on the crown and predict the pattern of movement of maxillary central incisor. At the same time, the amount of force and moment caused by activation of the loop which was used for retraction of maxillary central incisor was analyzed by Finite Element Method. We observed the following results: 1) We could control the stress distribution on the periodontal ligament by proper moment/force ratio on maxillary right central incisor and predict the pattern of movement of maxillary right central incisor. 2) The amount of stress on the periodontal ligament as well as the moment/force ratio demanded by each pattern of movement increased as the destruction of alveolar bone was worse. 3) The moment/force ratio demanded by each pattern of movement decreased as the angle between the maxillary central incisor and occlusal plane decreased. 4) The force with the open loop was shown to be large compared to that with the closed loop. Also, the force with the helix decreased by 30% compared to that without the helix. 5) Under the same conditions we observed a larger moment/force ratio when the open loop and/or the helix were used.

• 말소리와 음성과학
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• 제6권1호
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• pp.21-30
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• 2014

This study aims to discuss pitch slope on Korean intonation curve in spontaneous speech data. For this study, 656 utterances were taken in the spoken corpus and used 'close-copy stylization'. And then the physical feature of pitch movements was extracted for the study. The pitch slope was calculated on the basis of time and pitch range in each utterance. As a result, the average and distribution of pitch slope is similar between men and women in the range of the pitch movement except for essential differences. The slope of pitch movement confirms that there are no differences between men and women. Pitch slope on a scale of -10 to 10 is 90% of the entire pitch slope; pitch slope that moves by time scale without curve is 33.1%; pitch slope that moves half of the pitch bandwidth during the average time for pitch movement is 23.4%; pitch slope that moves 100% of pitch bandwidth during a half of the average time for pitch movement is 10.4%. Those results imply the possibility of standardization methods of Korean intonation by pitch slope.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.115-120
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• 2003

In this study, smoke movement in tunnel fires was investigated with various aspect ratio(0.5, 0.667, 1.0, 1.5, 2.0) of tunnel cross section. Reduced-scale experiments were carried out under the Froude scaling using 8.27 kW ethanol pool fire. Temperatures were measured under the ceiling and vertical direction along the center of the tunnel. Smoke front velocity and temperature decrease rate were reduced as higher aspect ratio of the tunnel cross-section. Smoke movement was evaluated by analysis of vertical temperature distribution 3 m downstream from the fire source. Elevation of smoke interface according to N percent rule was under about 60% of tunnel height.

• 대한의용생체공학회:의공학회지
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• 제2권1호
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• pp.21-30
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• 1981

In this study, measuring eye movements with E.O.G. to targets beyond 20$^{\circ}$ from fixation point, results are as follows. (1) When the eyes turn toward targets of more than 20$^{\circ}$ eccentricity, the first saccadic eye movement falls short of the target. The presence of image of the target off the fovea(visual error signal) subsequent to such an undershoot elicits, after short interval, corrective saccadic eye movements(usually one) which place the image of the target on the fovea. (2) There are different programming modes at retina for eye movement to targets within and beyond 20$^{\circ}$ from the fixation point. (3) Saccadic system, preparing the direction and amplitude of eye movement completes the corrective saccadic eye movements. (4) Distribution of latency and intersaccadic interval(I.S.I.)are frequently multi modal, with a seperation between modes of 25[msec]. (5) There are two types of saccadic eye movements for the double-step targets. This fact suggests that the visual information is sampled stochastically. (6) The new model of saccadic system including the dissociation of visual functions dependent on retinal eccentricity is required.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2001년도 춘계학술대회 논문집
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• pp.151-155
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• 2001

The purpose of this study is to investigate the weldline movement of the laser welded sheets during the warm deep drawing process. For this investigation, Five steps of temperature ranges, from room temperature to $200^{\circ}C$, and two kinds of thickness combination, 0.8 mm${\times}$1.2 mm and 0.8 mm${\times}$1.6 mm SCP1 material sheets, were adopted. Also, the numerical analysis using the PAM-STAMP has been carried out with the same models as the specimens. As a result the higher temperature was adopted, the less weld-line movement was observed.

• 대한치과보철학회지
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• 제20권1호
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• pp.83-91
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• 1982

The mandibular movement during mastication has been studied, however there is still much controversy, therefore the purpose of this study was to establish the fundamental data in order to provide the functional occlusion and information in prosthodontic treatment, and the diagnosis of temporomandibular joint disorder. The author analyzed the characteristics of the border and masticatory movements using the Mandibular Kinesiograph. The value, direction, deviation angulation of the border and masticatory movements were studied on the sagittal and frontal planes in 24 male subjects age of 22-28 without orofacial problems. The obtained results were as follows: 1. The values of border movement on the sagittal plane were an average of $25.81{\pm}5.14mm$ in vertical component and $24.37{\pm}3.76mm$ in ant-post component, and the posterior terminal hinge movement, $9.31{\pm}3.62mm$ in vertical component and $7.59{\pm}2.65mm$ in ant-post. component. 2. The distribution range of the masticatory movement within the border movement was an average of $19.2{\pm}12.81%$ of maximum ant-post, values and $55.5{\pm}16.1%$ of maximum values of border movement, and the movement path, for the most part, was directed to posterior deviation and ranged from 0.98 to 12.00mm, on an average of $5.15{\pm}3.49mm$. 3. On the frontal plane, a number of left and right deviation in 24 subjects was same, however, the right deviation was an average of $2.51{\pm}1.67mm$ compared with the left deviation. 4. On the frontal plane, the point of maximum lateral deviation was an average of $49.7{\pm}11.0%$ of maximum opening values. 5. The angulation between the terminal hinge movement path and the masticatory path was an average of $24.00{\pm}4.65$.