• Title/Summary/Keyword: Sentinel

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Estimation of water level over Hwanggang Dam using satellite image (위성영상을 활용한 북한 황강댐 수위 추정)

  • Choi, Sunghwa;Lee, Jaehee
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.385-388
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    • 2018
  • 군남댐의 운영은 북한지역에 위치한 저수지와 하천 상황, 특히 황강댐 방류에 절대적으로 의존하는 특성이 있음에도 불구하고, 수위 상황 등 자료수집의 한계로 군남댐 운영에 어려움이 많다. 이러한 상황에서 위성원격탐사 영상자료는 미계측 북한 접경지역의 수문상황을 판단하는 데 유용한 자료가 될 수 있다. 위성을 통한 수위 추정 방법은 위성영상에서 탐지된 수표면을 DEM과 중첩하여 판독하는 방법인 imaging 기법과 레이더고도계로 불리는 altimeter로 위성에서 수표면까지의 거리를 직접 측정하여 산출하는 profiling 기법 등 크게 두 가지 방법이 있다. 본 연구에서는 위성영상으로 산출된 DEM과 ESA의 Sentinel-1 C-밴드 SAR 영상을 중첩하여 황강댐 수위를 추정해 보았다. 정확도 문제가 있겠지만, 황강댐 수위 변화의 경향성은 확인할 수 있었으므로, 향후 개선을 통해 황강댐 수위변동 추세 분석과 상황별 적절한 사전 대응에 활용할 수 있을 것으로 판단된다.

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Estimation of Inundation Area and Discharge in River Using SAR Satellite Imagery (SAR 영상을 활용한 하천 유량 추정)

  • Seo, Minji;Ahmad, Waqas;Kim, Dongkyun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.313-313
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    • 2018
  • 유량 자료는 수자원 계획 및 개발, 정책결정, 관련 시설 운영 등의 가장 기초가 되는 핵심 자료이다. 하지만 전세계적으로 많은 유역에서 경제적 이유 등으로 인해 현장에서 정확한 유량 자료를 확보하는데 한계가 있다. 본 연구에서는 이러한 문제점을 극복하고자 SAR 영상을 활용한 하천의 유량 추정 기법을 개발하였다. 악천후 및 주야의 영향을 받지 않는 SAR 영상 자료인 유럽항공우주국 ESA(European Space Agency)의 Sentinel-1 영상자료와 함께 한강홍수통제소에서 제공하는 지상 관측 자료를 사용하여, 위성 영상자료에서 하천의 면적을 추출한 후 유량과의 상관관계를 분석하였다. 촬영 시간 등에 의한 위성 영상의 조도 차이에 따른 하천 면적의 오차를 제거하기 위하여 각 관측소별로 영상을 보정하였고 주변 지역에 의한 오차를 줄이기 위하여 하천유역을 분리하여 면적을 추출하였다. 이를 통해 하천 면적과 유량의 상관관계를 파악하였다. 국내 10여 개의 하천에 대하여 기법을 적용한 결과, 유량을 비교적 정확히 추정할 수 있었다. 본 연구의 결과는 미계측 유역의 수자원 관리 능력을 향상시킬 것으로 기대된다.

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Intravenous Pyogenic Granuloma in Sentinel Vein: A Case Report (전초정맥에 발생한 정맥관 내 화농성 육아종: 증례보고)

  • Hong, Ki Yong;Jeong, Eui Cheol;Min, Xianghua;Minn, Kyung Won;Lee, Young Jik
    • Archives of Craniofacial Surgery
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    • v.11 no.1
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    • pp.62-64
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    • 2010
  • Purpose: Lobular capillary hemangioma is a vascular tumor that commonly occurs as a cutaneous lesion. Intravenous pyogenic granuloma is a rare form of lobular capillary hemangioma that usually occurs in the veins of the neck and the upper extremities. Methods: A 41-year-old man presented with 3 months history of nodules on the left temporal area and these lesions were clinically mistaken for a typical lipoma or epidermal cyst, but the nodules appeared unusually vascular with sentinel veins on excision. Results: On the histopathologic examination, the excised tissue was observed as an intraluminal polypoid mass, which was attached to the vein via a fibrovascular stalk and capillaries in a loose edematous fibromyxoid stroma, and so the lesions were confirmed to be intravenous pyogenic granuloma. At 6 months after excision, there has been no recurrence and the patient is asymptomatic. Conclusion: Intravenous pyogenic granuloma is a rare variant of lobular capillary hemangioma. This article describes the surgical and histopathological findings of treating pyrogenic granuloma.

A Breast Cancer Nomogram for Prediction of Non-Sentinel Node Metastasis - Validation of Fourteen Existing Models

  • Koca, Bulent;Kuru, Bekir;Ozen, Necati;Yoruker, Savas;Bek, Yuksel
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.3
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    • pp.1481-1488
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    • 2014
  • Background: To avoid performing axillary lymph node dissection (ALND) for non-sentinel lymph node (SLN)-negative patients with-SLN positive axilla, nomograms for predicting the status have been developed in many centers. We created a new nomogram predicting non-SLN metastasis in SLN-positive patients with invasive breast cancer and evaluated 14 existing breast cancer models in our patient group. Materials and Methods: Two hundred and thirty seven invasive breast cancer patients with SLN metastases who underwent ALND were included in the study. Based on independent predictive factors for non-SLN metastasis identified by logistic regression analysis, we developed a new nomogram. Receiver operating characteristics (ROC) curves for the models were created and the areas under the curves (AUC) were computed. Results: In a multivariate analysis, tumor size, presence of lymphovascular invasion, extranodal extension of SLN, large size of metastatic SLN, the number of negative SLNs, and multifocality were found to be independent predictive factors for non-SLN metastasis. The AUC was found to be 0.87, and calibration was good for the present Ondokuz Mayis nomogram. Among the 14 validated models, the MSKCC, Stanford, Turkish, MD Anderson, MOU (Masaryk), Ljubljana, and DEU models yielded excellent AUC values of > 0.80. Conclusions: We present a new model to predict the likelihood of non-SLN metastasis. Each clinic should determine and use the most suitable nomogram or should create their own nomograms for the prediction of non- SLN metastasis.

Concordant Surgical Treatment: Non-melanocytic Skin Cancer of the Head and Neck

  • Ryu, Wan Cheol;Koh, In Chang;Lee, Yong Hae;Cha, Jong Hyun;Kim, Sang Il;Kim, Chang Gyun
    • Archives of Craniofacial Surgery
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    • v.18 no.1
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    • pp.37-43
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    • 2017
  • Background: Skin cancer is the most common type of cancer. Of the 4 million skin lesions excised annually worldwide, approximately 2 million are considered cancerous. In this study, we aimed to describe a regional experience with skin cancers treated by a single senior surgeon and to provide a treatment algorithm. Methods: The medical records of 176 patients with head and neck non-melanocytic skin cancer (NMSC) who were treated by a single surgeon at our institution between January 2010 and May 2016 were retrospectively reviewed, and their data (age, sex, pathological type, tumor location/size, treatment modality) were analyzed. Patients with cutaneous squamous cell carcinoma (cSCC) who were classified as a high-risk group for nodal metastasis underwent sentinel node mapping according to the National Comprehensive Cancer Network guidelines. Results: Among the patients with NMSC who were treated during this period, basal cell carcinoma (BCC; n=102, 57.9%) was the most common pathological type, followed by cSCC (n=66, 37.5%). Most lesions were treated by complete excision, with tumor-free surgical margins determined via frozen section pathology. Thirty-one patients with high-metastasis-risk cSCC underwent sentinel node mapping, and 17 (54.8%) exhibited radiologically positive sentinel nodes. Although these nodes were pathologically negative for metastasis, 2 patients (6.5%) later developed lymph node metastases. Conclusion: In our experience, BCC treatment should comprise wide excision with tumor-free surgical margins and proper reconstruction. In contrast, patients with cSCC should undergo lymphoscintigraphy, as nodal metastases are a possibility. Proper diagnosis and treatment could reduce the undesirably high morbidity and mortality rates.

Targeting of BUB1b Gene Expression in Sentinel Lymph Node Biopsies of Invasive Breast Cancer in Iranian Female Patients

  • Mansouri, Neda;Movafagh, Abolfazl;Sayad, Arezou;Pour, Atefeh Heidary;Taheri, Mohammad;Soleimani, Shahrzad;Mirzaei, Hamid Reza;Shargh, Shohreh Alizadeh;Azargashb, Eznollah;Bazmi, Haleh;Moradi, Hossein Allah;Zandnia, Fatemeh;Hashemi, Mehrdad;Massoudi, Nilofar;Mortazavi-Tabatabaei, SA
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.sup3
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    • pp.317-321
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    • 2016
  • Detection of micrometastasis in sentinel lymph nodes (SLNs) is a very useful tool for appropriate assessment of the clinical stage of disease in breast cancer patients. Early identification of clinically relevant disease could lead to early treatment or staging approaches for breast cancer patient. Micrometastases in SLNs of women with invasive breast cancer are of great significance in this context. In this study we examined SLN biopsies considered to have small numbers of cancerous cells by real time RT-PCR. All of the samples underwent immunohistochemical staining for cytokeratin for confirmation of the presence or absence of micrometastases. BUB1b expression assay of selected patients with and without metastasis showed overexpression in the former, but not in normal breast and lymph node tissue. Our results may be taken into account in the discussion about the merits of routine use of molecular assessment in pathogenetic studies of SLNs.

The Method of Linking Fire Survey Data with Satellite Image-based Fire Data (산불피해대장 정보와 위성영상 기반 산불발생데이터의 연계 방안)

  • Kim, Taehee;Choi, Jinmu
    • Korean Journal of Remote Sensing
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    • v.36 no.5_3
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    • pp.1125-1137
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    • 2020
  • This study aimed to propose the method of linking satellite image-based forest fire data to supplement the limitation of forest fire survey data that records only the ignition location and area of forest fire. For this purpose, a method was derived to link the fire survey data provided by the Korea Forest Service between January 2012 and December 2019 with MODIS and VIIRS image-based forest fire data. As a result, MODIS and VIIRS-based forest fire data out of 191 wildfires in the forest fire survey data were able to identify 11% and 44% of fire damage area, respectively. An average of 56% of forest damage area was extracted from VIIRS-based forest fire data compared to forest fire areas identified by high-resolution Sentinel-2A satellites. Therefore, for large-scale forest fires, VIIRS wildfire data can be used to compensate for the limitations of forest fire survey data that records only the ignition location and area.