• 대한치과마취과학회지
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• 제12권3호
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• pp.173-176
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• 2012

Certain oral procedures require a sedated patient who is responsive to allow for the mouth opening and position change. Dexmedetomidine is a relatively selective alpha2-adrenoceptor agonist with sedative, analgesic, amnestic, and anesthetic-sparing effects. Large dose dexmedetomidine is suitable as a single agent for sedation and anxiolysis for plate removal in a patient with bilateral sagittal split osteotomy and Lefort 1 osteotomy with genioplasty.

• Journal of Welding and Joining
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• 제23권1호
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• pp.48-54
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• 2005

Laser keyhole welding is investigated using a three-dimensional Gaussian heat source, and the heat source parameters such as the keyhole depth, welding efficiency and power density distribution factor are determined in a systematic way. For partial penetration, the keyhole depth is same as the penetration and is predicted using the experimental data. The welding efficiency is calculated using the ray-tracing method and the power density distribution factor is determined from the bead shape. Full penetration is classified into the transition, normal and excessive modes depending on the degree of keyhole opening. Thermal analysis of the bead-on-plate welds is conducted using the Gaussian heat source, and the calculated weld geometries show reasonably good agreements with the experimental results.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 1992년도 수공학연구발표회논문집
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• pp.133-141
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• 1992

A three water-intake structure designed to built along the right bank of the Missouri River near Chesterfield, Missouri was model-tested at an undistorted scale of 1:5. Although the discharge capacity of each of six pumps to be installed is only 21,000 gpm, the model indicated strong flow circuation and unstable free-surface conditions as flow entered the two-pump bay through a narrow sluice opening at an angle. Strong free-surface vartices were also observed in the model. The sump modifications developed in the study included an array of baffle bars, a perforated plate, floor splitters, and floor-corner fillets. The solutions developed in this study could be applied to other pump sumps with multiple pump units.

• 한국생산제조학회지
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• 제6권2호
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• pp.26-33
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• 1997

In this study effect of residual stress and its redistribution in weldment on the fatigue crack propagation was investigated. Fatigue tests were conducted by the center notched specimens machined with welded plate. The residual stress and its redistribution after the crack growth were measured by the magnetizing stress indicator and hole-drilling method. Fatigue crack propagation was estimated by the specimens having residual stress redistributed after the cracks growth and having the effects of crack closure. Crack growth rates were predicted and compared with experimental results. It had been found that the predicted crack propagation rates have a good agreement with experimental results when the redistribution of residual stress was considered.

• 한국해양공학회지
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• 제4권1호
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• pp.81-87
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• 1990

Fatigue crack closure levels based on the behavior of residual displacements on crack surfaces, are determined analytically according to the microscopic crack closure mechanisms, i.e., whether the first contact of crack surfaces takes place at the very crack tip or on the surfaces near the tip. The comparative analysis on the two models is carried out empirically by the constant amplitude fatigue tests on 2024-T3 aluminum alloy plate, and it shows that under negative stress ratio, the case of the first contact at crack tip gives better agreement with the experimental results than the other.

• 한국해양공학회지
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• 제4권1호
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• pp.87-87
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• 1990

Fatigue crack closure levels based on the behavior of residual displacements on crack surfaces, are determined analytically according to the microscopic crack closure mechanisms, i.e., whether the first contact of crack surfaces takes place at the very crack tip or on the surfaces near the tip. The comparative analysis on the two models is carried out empirically by the constant amplitude fatigue tests on 2024-T3 aluminum alloy plate, and it shows that under negative stress ratio, the case of the first contact at crack tip gives better agreement with the experimental results than the other.

• 대한기계학회논문집B
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• 제28권12호
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• pp.1511-1520
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• 2004

A flow visualization of the two-dimensional rigid fling-clap motions of the flat-plate wing are performed to gain knowledge of butterfly mechanisms that might be employed by butterflies during flight. In this numerical visualization, the time-dependent Navier-Stokes equations are solved for cyclic fling and clap types of wing motion. The separation vortex pair that is developed in the fling phase of the cyclic fling and clap motion is observed to be stronger than those of the fling followed by clap and pause motion(1st cycle motion). This stronger separation vortex pair in the fling phase is attributable to the separation vortex pair of the outside space developed in the clap phase as it moves into the opening in the following fling phase. Accordingly, higher lift and power expenditure coefficients in the fling after clap phase is caused by the stronger separation vortex pair.

• 한국소음진동공학회논문집
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• 제25권7호
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• pp.503-509
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• 2015

Based on ISO 7235, an experimental setup to measure the acoustic performance of splitter type dissipative silencers was fabricated. The length of each duct, sound source, microphone locations, modal filter, and anechoic termination were considered in the design of this setup. The modal filter is a particularly important factor because it affects the limit of measurement. The effects of number of splitters, absorptive material density, perforate plate, and media on the noise reduction of the sample silencers were experimentally investigated. The experimental results show that the insertion loss of a silencer with media, high perforate opening, and higher number of splitters increases especially at higher frequencies.

• Journal of Biosystems Engineering
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• 제22권2호
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• pp.163-176
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• 1997

Sesame was one of the economical crops in Korea. However, cultivation area of sesame has been decreasing rapidly due to the lack of mechanization for this crop and the opening of agricultural product market. Sesame seed is so small that ordinary seeder can not seed properly. In rural practice, farmers seed sesame with hand and do thinning after shoot emerges. Seeding and thinning in sesame cultivation take more than 40% of total labor To reduce labor in seeding and thinning, a pellet seed machine for sesame has been developed. The pellet seed machine is very simple in structure. It utilizes the chemical reaction between alginate solution and $CaCl_2$. Two material forms a membrane when they meet The uniqueness of the pellet seed machine for sesame were 1) a counter rotating roller for metering the mixture of activated carbon and alginate and 2) swinging plate for submerging seed into the mixture. The prototype machine can produce 30, 000 pellets per hour and costs ￦6, 891 per 1 km sesame.

• 한국산업정보학회:학술대회논문집
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• 한국산업정보학회 2002년도 춘계학술대회 논문집
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• pp.343-347
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• 2002

본 논문에서 는 자동차 영상에서 모폴로지 연산을 이용한 번호판 추출 방법을 제안한다. 먼저 입력 받은 자동차 영상을 적응적 임계값을 적용하여 이진화 한다. 이 진화 영상에 대하여 모폴로지 연산의 침식/팽창 과정을 연속적으로 수행하여 번호판 내의 문자영역을 제거하는 opening과정 과 팽창/침식 과정을 연속적으로 수행하여 번호판 내의 문자영역을 확장하는 closing 연산을 병렬 수행한 후 그들간의 차영상을 추출한다. 추출된 차영상에 Geo-correction과 번호판의 일반적인 특성을 이용한 필터링 작업을 수행하여 실제 번호판 영역을 추출한다. 제안한 방법을 구현하고 다양한 각도에서 취득된 다양한 형태의 자동차 영상에 적용하여 본 알고리즘의 효용성을 보인다.