• Proceedings of the Korea Water Resources Association Conference
• /
• 2021.06a
• /
• pp.277-277
• /
• 2021

합류부는 인공수로 또는 자연하천에서 흔히 존재하며 매우 복잡한 흐름 구조가 발생하는 곳이다. 특히 본류와 지류의 유속장의 차이에 따라 발생하는 전단층은 흐름과 물질이 혼합되는 경계면이 되며, 흐름 구조가 전단층을 따라 발달한다는 특징으로 인해 수리학적으로 매우 중요하다. 최근 원격탐사 기법의 발전에 따라 위성이나 드론과 같은 무인 이동체를 이용한 하천 계측법이 수질 및 지형변화 연구들에 광범위하게 적용되고 있다. 그 중 RGB 항공영상은 해상도가 높고 취득 비용이 저렴하여 확장성 및 활용도가 높다. 본 연구에서는 합류부 전단층이 촬영된 RGB 항공 영상을 이용해 합류부 전단층 분석에 활용하는 방법을 제안한다. 제안되는 방법은 RGB 항공 영상에서 본류와 지류의 수체 영역을 각각 추출하기 위해 가우시안 혼합 모형(Gaussian mixture model)을 이용한다. 추출된 수체 영역에는 자기조직화지도(self-organizing map)을 적용하고 좌표 변환을 하여 정량적인 특징을 추출한다. 본 연구에서는 알고리듬의 적용 예로서 구글어스를 통해 확보된 낙동강-남강 합류부의 항공 영상을 분석한다. 본 추출법을 이용하면 접촉식 센서를 이용하는 기존의 전단층 계측 방법들에 비해 경제적이고 안전하며 합류부 흐름의 평면적 분석을 가능하게 할 수 있을 것으로 기대된다.

• Journal of Veterinary Clinics
• /
• v.31 no.2
• /
• pp.117-120
• /
• 2014

An 11-year-old intact female Maltese was referred because of 1 week history of cluster seizure episodes. Based on brain CT scan, brain tumor was strongly suspected. The patient was euthanized according to client's request and we performed necropsy after euthanasia. The gross findings of the postmortem coronal sections of the brain showed that the mass was relatively well-demarcated, reddish in colored, and was present inside the left lateral ventricle and compressed adjacent tissues. The tumor mass had 2 distinct histopathological features: perivascular pseudorosette-like structures and a whirl-like arrangement of fibrillary cells. The immunohistochemical profile showed strong GFAP positivity and moderate S-100 expression, sparsely dotted staining with Ki-67. Based on the histopathological and immunohistochemical findings, the present case diagnosed to ependymoma.

• Journal of Digital Convergence
• /
• v.12 no.6
• /
• pp.433-438
• /
• 2014

This study aims to get more accurate and objective result by quantifying the result for the sperm changes through the quantitative analysis by the image processing based on the image obtained microscopically for the testicle cell and sperm change appeared with the passage of time when the radiation is irradiated to the white rat testicle. This study has targeted the white rat of 8 weeks lifespan, the X-ray of 6 MV with 1 time of 2 Gy has been irradiated to the whole body. The testicles of 5 rats at each test group immediately after irradiation, after 2 hours of irradiation, 4 hours, 8 hours and 24 hours has been respectively extracted targeting all 30 white rats of normal control group not irradiated by the radiation and the test group. The state of testicle cell and sperm has been observed in the normal control group and the test group by implementing Periodic acid Schiff dyeing after extraction. 24 hours after irradiation, a gradual decrease in sperm count and testicular cells qualitatively and quantitatively that were identified as significant.

• Journal of Korea Water Resources Association
• /
• v.54 no.8
• /
• pp.553-566
• /
• 2021

River confluence is often characterized by shear layer and the associated strong mixing. In natural rivers, the main channel and its tributary can be separated by the shear layer using contrasting colors. The shear layer can be easily observed using aerial images from satellite or unmanned aerial vehicles. This study proposes a low-cost identification method extracting geographic features of the shear layer using RGB aerial image. The method consists of three stages. At first, in order to identify the shear layer, it performs image segmentation using a Gaussian mixture model and extracts the water bodies of the main channel and tributary. Next, the self-organizing map simplifies the flow line of the water bodies into the 1-dimensional curve grid. After that, the curvilinear coordinate transformation is performed using the water body pixels and the curve grid. As a result, the shear layer identification method was successfully applied to the confluence between Nakdong River and Nam River to extract geometric shear layer features (confluence angle, upstream- and downstream- channel widths, shear layer length, maximum shear layer thickness).

• Science of Emotion and Sensibility
• /
• v.15 no.4
• /
• pp.585-592
• /
• 2012

Food is crucial for the nutrition and survival of humans. Taste system is one of the fundamental senses. Taste cells detect and respond to five basic taste modalities (sweet, bitter, salty, sour, and umami). However, the cortical processing of taste sensation is much less understood. Recently, there were many efforts to observe the brain activation in response to taste stimulation using functional magnetic resonance imaging (fMRI), magnetoencephalography (MEG), and optical imaging. These different techniques do not provide directly comparable data each other, but the complementary investigations with those techniques allowed the description and understanding of the sequence of events with the dynamics of the spatiotemporal pattern of activation in the brain in response to taste stimulation. The purpose of this study is the understanding of the brain activities to taste stimuli in sensory and affective aspects and the reviewing of the recent research of the gustotopic map by functional brain mapping.

• Nuclear Medicine and Molecular Imaging
• /
• v.43 no.1
• /
• pp.26-34
• /
• 2009

Purpose: The purpose of this study was to find out what clinicopathologic or immunohistochemical parameter that may affect FDG uptake of primary tumor in PET/CT scan of the gastric carcinoma patient. Materials and Methods: Eighty-nine patients with stomach cancer who underwent pre-operative FDG PET/CT scans were included. In cases with perceptible FDG uptake in primary tumor, the maximum standardized uptake value (SUVmax) was calculated. The clinicopathologic results such as depth of invasion (T stage), tumor size, lymph node metastasis, tumor differentiation and Lauren's classification and immunohistochemical markers such as Ki-67 index, expression of p53, EGFR, Cathepsin D, c-erb-B2 and COX-2 were reviewed. Results: Nineteen out of 89 gastric carcinomas showed imperceptible FDG uptake on PET/CT images. In cases with perceptible FDG uptake in primary tumor, SUVmax was significantly higher in T2, T3 and T4 tumors than T1 tumors ($5.8{\pm}3.1$ vs. $3.7{\pm}2.1$, p=0.002). SUVmax of large tumors (above or equal to 3 cm) was also significantly higher than SUVmax of small ones (less than 3 cm) ($5.7{\pm}3.2$ vs. $3.7{\pm}2.0$, p=0.002). The intestinal types of gastric carcinomas according to Lauren showed higher FDG uptake compared to the non-intestinal types ($5.4{\pm}2.8$ vs. $3.7{\pm}1.3$, p=0.003). SUVmax between p53 positive group and negative group was significantly different ($6.0{\pm}2.8$ vs. $4.4{\pm}3.0$, p=0.035). No significant difference was found in presence of LN metastasis, tumor differentiation, Ki-67 index, and expression of EGFR, Cathepsin D, c-erb-B2 and COX-2. Conclusion: T stage of gastric carcinoma influenced the detectability of gastric cancer on FDG PET PET/CT scan. When gastric carcinoma was perceptible on PET/CT scan, T stage, size of primary tumor, Lauren's classification and p53 expression were related to degree of FDG uptake in primary tumor.

• Journal of Chest Surgery
• /
• v.36 no.1
• /
• pp.35-38
• /
• 2003

Glomus tumors are uncommon lesions of glomus cell origin with structural and immunohistochemical features of smooth muscles. Primary glomus tumors of the lung and bronchus are extremely rare and only several cases have been reported. A 16-year-old woman was admitted for the complaint of productive cough, fever, and dyspnea. Imaging studies revealed a protruding mass in the left main bronchus and the mass was completely resected via a left thoracotomy incision. We report this case with literature review.

• The Journal of Korean Association of Computer Education
• /
• v.9 no.2
• /
• pp.101-109
• /
• 2006

We propose an adaptive digital watermarking algorithm using HVS(human visual system) and SOM(Self-Organizing Map) among neural networks. This method adjusts adaptively the strength of the watermark which is embedded in different blocks according to block classification in DCT(Discrete Cosine Transform) domain. All blocks in 3 classes out of 4 are selected to embed a watermark. Watermark sequences are embedded in 6 lowest frequency coefficients of each block except the DC component. The experimental results are excellent.

• Nuclear Medicine and Molecular Imaging
• /
• v.43 no.6
• /
• pp.557-564
• /
• 2009

Purpose: To evaluate the relationship between F-18 FDG uptake of tumor in PET/CT scan and pathological or immunohistochemial parameters of colorectal cancer. Materials and Methods: 147 colorectal cancer patients who underwent both pre-operative F-18 FDG PET/CT scan and surgery were included. In cases with perceptible FDG uptake in primary tumor, the maximum standardized uptake value (SUVmax) was calculated. The pathologic results such as site, size, depth of invasion (T stage), growth pattern, differentiation of primary tumor, lymph node metastasis and Dukes-Astler & Coller stage and immunohistochemical markers such as expression of EGFR, MLH1, MSH2 and Ki-67 index were reviewed. Results: 146 out of 147 PET/CT scans with colorectal cancer showed perceptible focal FDG uptake. SUVmax showed mild positive linear correlation with size of primary tumor (r=0.277, p=0.001) and Ki-67 index (r=0.226, p=0.019). No significant difference in F-18 FDG uptake was found according to site, depth of invasion (T stage), growth pattern, differentiation of primary tumor, presence of lymph node metastasis, Dukes-Astler & Coller stage and expression of EGFR. Conclusion: The degree of F-18 FDG uptake in colorectal cancer was associated with the size and the degree of Ki-67 index of primary tumor. It could be thought that FDG uptake of primary tumor has a correlation with macroscopic and microscopic tumor growth.

• Korean Journal of Head & Neck Oncology
• /
• v.23 no.2
• /
• pp.133-137
• /
• 2007

With the wide use of ultrasonography and fine needle aspiration of the thyroid gland, the incidence of papillary microcarcinoma of the thyroid gland is rapidly increasing nowadays. To improve the diagnostic accuracy of histopathologic findings of papillary thyroid carcinoma, various molecular markers have been used recently. We analysed the expression of galectin-3, cytokeratin 19 and HBME-1, using immunohistochemical technique in 37 cases of papillary microcarcinoma of the thyroid gland to evaluate the diagnostic value of these molecular markers. Immunohistochemically, galectin-3 expression was found in 37 cases of papillary microcarcinoma. Its localization was mostly cytoplasmic. Cytokeratin 19 expression was found in 36 cases. It was mostly localized to the cytoplasm and membrane. HBME-1 expression was found in all cases. Its localization was plasma membrane. The expression of these three molecular markers was negative in the adjacent normal thyroid tissue and accompanying benign lesions, although there are scattered foci of incomplete positive staining in cases of Hashimoto's thyroiditis. Our findings suggest that the immunohistochemical staining using antibodies for galectin-3, cytokeratin 19 and HBME-1 is an useful adjunctive method for the histopathological diagnosis of a papillary microcarcinoma of the thyroid gland.