• 대한의용생체공학회:의공학회지
• /
• 제8권1호
• /
• pp.81-86
• /
• 1987

An image feature extraction method for the low contrast fluoresceln angiogram in dlabetes was studied. To obtain effective image segmentation, an adaptive local difference image is generated and relaxation process are applied to this difference Image. By the use of distance transformed data with segmented image, shape and location of feature regions were obtained. It was shown that the location and shape descriptions of Impaired blood vessel networks and retinal regions are can he utilized for the diagnosis of diabetes and other disease.

• 한국염색가공학회:학술대회논문집
• /
• 한국염색가공학회 2009년도 제41차 학술발표회
• /
• pp.115-116
• /
• 2009

In this study, near-infrared absorbing dyes, namely, new rigidified heptamethine cyanine dyes were synthesized and investigated their properties. The cyanine dyes have been synthesized by a condensation reaction between a quanternary salt containing as activated methyl group and an unsaturated bisaldehyde or its equivalent. We were investigated the synthesis of new rigidified heptamethine cyanine and related the compounds with near infrared absorption. The full spectroscopic characterization of all cyanine were described. Absorption properties in the near-infrared region may cause these dyes to the potential used in bio-probe, optical recording media materials.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 1998년도 제17회 KOSCI SYMPOSIUM 논문집
• /
• pp.91-101
• /
• 1998

The effect of secondary flow on both methane/air and propane/air premixed flame was investigated experimentally. By changing the radius of curvature, various flame behavior was observed. In the V-bend nozzles, flame surface is deformed from axisymmetry. As the exit velocity increased, flame lifted off partially. When the radius of curvature of the V-bend increased, the region where premixed flame is entirely on the rim increased. Since the axial velocity field is changed due to the secondary flow effect, comparison of V-bend and straight tube with the same diameter shows larger V-bend nozzle exit velocity for both flash back and flame blowout. The flame characteristics are mapped with a equivalence ratio, a velocity, and a nozzle radius of curvature. To identify physical reasoning on the flame surface deformation, numerical calculations are conducted. OH radical distributions in flames are visualized by PLIF technique.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
• /
• pp.405-406
• /
• 2008

The amorphous indium zinc oxide (IZO) thin films were deposited on polyethersulfone (PES) and glass substrates by facing targets sputtering. IZO thin films deposited as functions of gas flow ratio on PES and glass substrates, respectively. The electrical, optical and structural properties of IZO thin films were evaluated by a Hall Effect Measurement, an X-Ray Diffractormeter, UV/VIS spectrometer in visible range and a scanning electron microscopy, respectively. As-deposited IZO thin films exhibited resistivity of $5.4\times10^{-4}$ and $4.5\times10^{-4}$ [$\Omega$-cm] on PES and glass substrates, respectively. The optical transmittance showed over 85% in the visible region on PES and glass substrates.

• 한국전기전자재료학회논문지
• /
• 제17권6호
• /
• pp.678-682
• /
• 2004

Generally Bi-2223/Ag tapes have a broad S/N transition region and their sheath is a good electric conductor. In this study, the current distribution between superconductor and metal sheath in HTS tapes were investigated. AC with its peak value above 10 times $I_{c}$ was applied to HTS tapes for around 6 cycles and V-I characteristics were measured. Using the resistance of the sheath and V-I curves, the current distribution between superconductor and metal sheath was calculated. When 150 $A_{p}$ was applied, more than 2/3 of the current flows through superconductor. However, in the case of 304 $A_{p}$, most of the applied current came to flow through the metal sheath at the 6th cycle.e.e.e.

• 한국임상수의학회지
• /
• 제19권3호
• /
• pp.371-374
• /
• 2002

A female 8-year-old Pug weighing 7.3 kg and a female 10-year-old Maltese dog weighing 3.5 kg showing anorexia and vomiting for a few weeks were referred to Veterinary Medical leaching Hospital, Seoul National University. Radiographic findings were an enlarged right kidney in a pug dog and a radiopaque material on the right ureteral region lateral to the third lumbar vertebrae with indefinite right kidney contour in a Maltese dog, repectively. Excretory urography performed in a Pug dog revealed a poor opacified enlarged right kidney with absent of pelvic recesses and pelvic dilation with proximal ureteral dilation on contralateral kidney. Ultrasonographic findings were enlarged kidney with dilated pelvis and echogenic sediment within the medulla in both dogs and especially an engorged proximal ureter and a thin rim of functional renal tissue remains in a Maltese dog. Those diagnostic findings indicated high possibility of pyelonephritis and these were confirmed by pathologic examination. Radiography and ultrasonography, although not giving final diagnosis for pyelonephritis, are useful for assessment and diagnosis of pyelonephritis.

• 자동차안전학회지
• /
• 제14권3호
• /
• pp.30-34
• /
• 2022

The CFT(Cornering Fatigue test) and RFT(Radial Fatigue Test) are tests for evaluating the endurance of the disc and rim region of the wheel. In recent, automobile wheel safety standards have been revised and the applied load and target life criteria are different from existing conditions. The verification evaluation of all wheels requires a lot of time and cost. In this study, the endurance severity of each test was compared through strain-life approach by selecting 4 steel and 8 aluminum wheels.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제31권2호
• /
• pp.130-136
• /
• 2005

Bone grafts are widely used in the reconstruction of osseous defects in the oral and maxillofacial region. Autogenous bone grafts are considered the gold standard in grafting of the oral and maxillofacial region, because of its osteoconductive and osteoinductive properties. Mandibular symphysis & ascending ramus bone graft have been used more frequently because of easy surgical access, reduced operative time, and following minimal morbidity. However, even though the frequent use of the anterior part of ascending ramus and the different regions of mandible, rare of the reports provide information about the quantity of bone available in this donor site. So this study was taken to evaluate & quantify the amount of bone graft material in the anterior ascending ramus regions. This study was made on 36 samples of CT image. In 3D volume image, imaginary osteotomy & segmentation were done and the dimensions and volume of the bone grafts were measured and evaluated. the average volume of the graft materials obtained from the ascending ramus was $3656.83{\pm}108.19mm^3$, and the average dimensions of graft materials were $(33.68{\pm}0.48){\times}(34.92{\pm}0.51){\times}(15.96{\pm}0.27){\times}(9.05{\pm}0.27)mm$.

• 방송공학회논문지
• /
• 제10권4호통권29호
• /
• pp.632-642
• /
• 2005

본 논문에서는 다각형 기반 윤곽선 근사화를 위한 새로운 정점 선택 방법을 제안한다. 제안 방법은 전체 윤곽선을 부분 윤곽선으로 분할하고, 분할된 각 부분 윤곽선을 가변적 정확도에 따라 적응적으로 근사화한다. 근사화 정확도는 각 부분 윤곽선의 상대적 중요도에 의해 결정된다. 이때 근사화 오차 영역에서 발생하는 밝기 왜곡을 고려하여 각 부분 윤곽선의 상대적 중요도를 결정함으로써, 같은 윤곽선 데이터 량으로 보다 높은 재생영상의 화질 향상을 이룰 수 있다. 이러한 개념을 바탕으로 영역간 대조와 최대허용오차($d_{max}$)와의 관계식을 유도하고, 이 식을 이용한 적응적 정점 선택 방법을 제안한다. 실험 결과, 제안된 방법이 영상 부호화의 측면에서 기존 기법보다 우수한 성능을 나타내었다.

• 한국멀티미디어학회논문지
• /
• 제16권12호
• /
• pp.1376-1384
• /
• 2013

본 논문에서는 산업용 CT 볼륨데이터에서 템플릿 매칭을 통하여 제품의 이물질을 자동 검출하는 기법을 제안한다. 제안방법은 다음과 같은 세 단계로 이루어진다. 첫째, 다운 샘플링 데이터에서 잡음제거 후 제품을 배경과 분리하고, 영상의 평균값 및 표준편차를 이용하여 초기 이물질 후보를 추출한 후, K-평균 클러스터링을 이용하여 이물질 후보를 추출한다. 둘째, 템플릿 매칭을 이용하여 제품과 유사도가 다른 이물질을 검출한다. 이 때, 검출하고자 하는 이물질의 크기에 따라 밝기값평균차이(SSD)와 조인트 엔트로피를 이용한 유사도 평가를 통하여 이물질을 검출한다. 셋째, 원 볼륨데이터에서 이물질 검출률을 개선하기 위하여 여과기법으로 제품의 이물질을 최종 검출한다. 본 제안 방법의 결과를 평가하기 위해 산업용 CT 볼륨데이터와 시뮬레이션 데이터를 사용하여 육안평가, 정확성 평가와 수행시간 측정을 수행하였다. 정확성 평가를 위하여 기존 밝기값 기반 검출 기법을 비교방법으로 사용하고, 다이스 계수 유사도를 측정하였다.