IEA(Iterative Error Analysis)와 분광혼합분석기법을 이용한 초분광영상의 변화탐지

송아람 ( Ahram Song ),최재완 ( Jaewan Choi ),장안진 ( Anjin Chang ),김용일 ( Yongil Kim ) 대한원격탐사학회 2015 大韓遠隔探査學會誌 Vol.31 No.5

초분광영상을 이용한 변화탐지 기법으로는 Chronochrome(CC), Principal Component Analysis (PCA), 분광혼합분석(spectral unmixing) 등이 있다. 특히, 분광혼합분석을 이용한 변화탐지는 변화객체의 위치 정보뿐만 아니라 변화의 속성까지 분석할 수 있다는 점에서 매우 효과적이나, 분광혼합분석을 활용한 초분광영상의 변화탐지 연구는 여전히 초기단계에 머물러 있다. 본 연구에서는 분광혼합분석을 이용한 효과적인 변화탐지를 위하여 Iterative Error Analysis(IEA)와 Spectral Angle Mapper(SAM) 등을 활용하여두 영상에서 변화지역을 설명할 수 있는 동일한 endmember를 결정하였으며, 점유비율의 차영상을 통하여 변화지역을 추출하였다. 제안기법의 적용성을 평가하기 위하여 임의의 변화지역을 포함한 Compact Airborne Spectrographic Imager(CASI) 및 Hyperion 모의영상에 대한 변화탐지를 수행하였다. 실험결과, 제안기법이 기존의 CC, PCA, N-FINDR를 이용한 분광혼합분석보다 효과적으로 변화지역을 추출할 수 있는 것으로 나타났다. 본 연구의 제안기법은 사전정보 없이 자동으로 동일한 endmember를 추출할 수 있는 장점을 갖기 때문에 다양한 피복물질로 구성된 영상의 변화탐지에 효과적으로 활용될 것이다. Various algorithms such as Chronochrome(CC), Principle Component Analysis(PCA), and spectral unmixing have been studied for hyperspectral change detection. Change detection by spectral unmixing offers useful information on the nature of the change compared to the other change detection methods which provide only the locations of changes in the scene. However, hyperspectral change detection by spectral unmixing is still in an early stage. This research proposed a new approach to extract endmembers, which have identical properties in temporally different images, by Iterative Error Analysis (IEA) and Spectral Angle Mapper(SAM). The change map obtained from the difference of abundance efficiently showed the changed pixels. Simulated images generated from Compact Airborne Spectrographic Imager (CASI) and Hyperion were used for change detection, and the experimental results showed that the proposed method performed better than CC, PCA, and spectral unmixing using N-FINDR. The proposed method has the advantage of automatically extracting endmembers without prior information, and it could be applicable for the real images composed of many materials.

한반도의 일사량 추정을 위한 청천일 모델의 비교 평가

송아람(Ahram Song),최원석(Wonseok Choi),윤창열(Changyeol Yun),김용일(Yongil Kim) 한국측량학회 2015 한국측량학회지 Vol.33 No.5

천리안 기상위성을 이용한 한반도 지역의 Linke turbidity 및 청천일사량 추정

송아람(Ahram Song),최강혁(Kanghyeok Choi),정민경(Minkyung Jung),김용일(Yongil Kim) 한국신재생에너지학회 2016 신재생에너지 Vol.12 No.S2

An estimation of the clear sky irradiance is a crucial part of satellite based methods because it is employed to calculate the clear sky index. Although the accuracy of the clear sky irradiance depends on the AOD (Aerosol Optical Depth) and TPW (Total Precipitable Water) mixing ratio, data are difficult to acquire in real time. The Linke turbidity factor simplifies the data as a unique parameter that describes the attenuation of solar radiation in terms of a clean and dry atmosphere. SoDa provides the Linke turbidity maps all over the world, but those maps have low spatial and temporal resolutions. To estimate the clear sky irradiance over the Korean Peninsula using satellite images, this paper presents a method to estimate the Linke turbidity factor using COMS MI, which is operated by the Korea Meteorological Administration, and the clear sky irradiance using the ESRA clear sky model. The AOD and the TPW derived from COMS MI were also used to calculate the Linke turbidity. Overall, the results show that the Linke turbidity factor calculated from COMS MI has higher accuracy than that calculated using the SoDa data.

개방형 다중 데이터셋을 활용한 Combined Segmentation Network 기반 드론 영상의 의미론적 분할

송아람,Ahram Song 대한원격탐사학회 2023 大韓遠隔探査學會誌 Vol.39 No.5

This study proposed and validated a combined segmentation network (CSN) designed to effectively train on multiple drone image datasets and enhance the accuracy of semantic segmentation. CSN shares the entire encoding domain to accommodate the diversity of three drone datasets, while the decoding domains are trained independently. During training, the segmentation accuracy of CSN was lower compared to U-Net and the pyramid scene parsing network (PSPNet) on single datasets because it considers loss values for all dataset simultaneously. However, when applied to domestic autonomous drone images, CSN demonstrated the ability to classify pixels into appropriate classes without requiring additional training, outperforming PSPNet. This research suggests that CSN can serve as a valuable tool for effectively training on diverse drone image datasets and improving object recognition accuracy in new regions.

Sulfuretin, a natural Src family kinases inhibitor for suppressing solar UV-induced skin aging

Han, Ahram,Lee, Jinhyuk,Lee, Myung-hee,Lee, Sung-Young,Shin, Eun Ju,Song, Young-Ran,Lee, Kwang Min,Lee, Ki Won,Lim, Tae-Gyu Elsevier 2019 Journal of Functional Foods Vol.52 No.-

<P><B>Abstract</B></P> <P>This study suggests sulfuretin as an ant-skin aging agent. Sulfuretin significantly reduces solar UV (sUV)-increased matrix metalloproteinase-1 (MMP-1) expression and c-Jun phosphorylation in human dermal fibroblasts as well as skin tissue. An examination of the underlying mechanisms showed that sUV-activated MAPK signaling pathways are blocked by sulfuretin. Interestingly, sulfuretin directly inhibits the kinase activity of selected Src family. Because the amino acid sequence of Hck kinase which used kinase array is 230–497, it was assumed that sulfuretin interacts with this conserved domain of Src family kinase. It was also found that sulfuretin directly binds to sulfuretin with the lowest binding energy of −8.9 kcal/mol and free energy of −10.07 kcal/mol. Additionally, Hck protein was precipitated with sulfuretin-conjugated Sepharose 4B beads in HDFs cell lysate. Overall, present findings indicated that sulfuretin plays the role of anti-skin aging agent by acting as a general Src family kinase inhibitor in human skin.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The anti-wrinkle formation activity of sulfuretin was suggested. </LI> <LI> Sulfuretin acts as general Src family kinase inhibitor. </LI> <LI> The expected interaction was assumed using computer modeling. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Association Between Low Anti-spike Antibody Levels After the Third Dose of SARS-CoV-2 Vaccination and Hospitalization due to Symptomatic Breakthrough Infection in Kidney Transplant Recipients

Han Ahram,Min Sangil,Jo Eun-Ah,Lee Hajeong,Kim Yong Chul,Han Seung Seok,Kang Hee Gyung,Ahn Yo Han,Oh Inseong,Song Eun Young,Ha Jongwon 대한진단검사의학회 2024 Annals of Laboratory Medicine Vol.44 No.1

Background: Whether anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody levels post-third coronavirus disease (COVID-19) vaccination correlate with worse outcomes due to breakthrough infection is unclear. We evaluated the association between anti-SARS-CoV-2 antibody levels and symptomatic breakthrough infection or hospitalization during the Omicron surge in kidney transplant recipients. Methods: In total, 287 kidney transplant recipients expected to receive a third vaccination were enrolled between November 2021 and February 2022. The Abbott SARS-CoV-2 IgG II Quant test (Abbott, Chicago, IL, USA) was performed within three weeks before and four weeks after the third vaccination. The incidence of symptomatic breakthrough infection and hospitalization from two weeks to four months post-third vaccination was recorded. Results: After the third vaccination, the seropositive rate and median antibody titer of the 287 patients increased from 57.1% to 82.2% and from 71.7 (interquartile range [IQR] 7.2–402.8) to 1,612.1 (IQR 153.9–5,489.1) AU/mL, respectively. Sixty-four (22.3%) patients had symptomatic breakthrough infections, of whom 12 required hospitalization. Lower anti-receptor-binding domain (RBD) IgG levels (<400 AU/mL) post-third vaccination were a risk factor for symptomatic breakthrough infection (hazard ratio [HR]=3.46, P<0.001). Anti-RBD IgG levels <200 AU/mL were a critical risk factor for hospitalization (HR=36.4, P=0.007). Conclusions: Low anti-spike IgG levels after third vaccination in kidney transplant recipients were associated with symptomatic breakthrough infection and, particularly, with hospitalization during the Omicron surge. These data can be used to identify patients requiring additional protective measures, such as passive immunization using monoclonal antibodies.

철도통합무선망 구축을 위한 국내 철도법령 분석 및 연구

송용수(YongSoo Song),정우석(Wooseok Jeong),심봉규(BongKyu Sim),조아람(AhRam JO) 한국철도학회 2013 한국철도학회 학술발표대회논문집 Vol.2013 No.5

최근 정보통신기술(ICT)산업이 국가핵심기술로 떠오르고 있는 실정에 맞춰 철도분야에서는 국가핵심산업의 발전을 위해「도시철도용 무선통신기반의 열차제어시스템 표준체계구축 및 성능평가 연구사업」1 단계를 2010 년부터 수행 중에 있다. 2014 년 1 단계 완료 후 일반철도 및 고속철도에 무선통신기반 철도시스템 연구개발 및 실용화를 목표로 하고 있다. 이러한 국가철도통합무선망의 효율적인 도입을 위한 기술적, 정책적 기반조성이 요구되고 있고, 철도통합무선망 건설에 필요한 법령, 기준, 제도 등에 대한 검토를 통하여 이들에 대한 보완 방안의 마련과 함께 실용화 사업의 효율적 추진이 되어야 할 것이다. recently, Rail industry is implementing "study of performence evaluation and standard system making of wireless communication train control system based on city rail" to develop national core technology, with situation of ICT industry is magnified as national core technology. 2014, after 1st part finished, it is the goal that practical use and study of wireless communication based rail system on Railway and High Speed Railway technical and political foundation construction work is being asked to introduct KRTCSefficiently, It is necessary to promote efficient operation along with the practical preparation through the examination rule, standard, system such as the the necessary factors construction of KRTCS.

스트리트뷰 영상의 객체탐지를 활용한 보행 장애물 정보 갱신

박슬아(Park, Seula),송아람(Song, Ahram) 한국측량학회 2021 한국측량학회지 Vol.39 No.6

성역할에 대한 여성의 태도와 사회적 규범이 출산에 미치는 영향 분석

조유선(Yusun Cho),문아람(Ahram Moon),송아영(Ahyoung Song) 비판과 대안을 위한 사회복지학회 2020 비판사회정책 Vol.- No.66

본 연구는 성평등주의적 관점에 근거하여 여성 개인의 성역할 태도와 성역할에 대한 사회적 규범이 출산결정에 미치는 영향을 분석하고자 하였다. International Social Survey Programme의 2012년 자료를 바탕으로 저출산 문제를 겪고 있는 26개국을 대상으로 경제활동 참여에 대한 성평등성과 양육역할에 대한 성평등성이 출산결정에 미치는 영향을 포아송회귀모형(poisson regression)을 통해 분석하였다. 분석 결과, 여성 개인의 성역할 태도보다는 사회적 규범이 자녀의 수에 더 큰 영향을 미칠 수 있음이 나타났다. 특히 경제활동참여에 대한 성평등성은 높지만 양육에 대한 성평등성은 낮은 사회적 규범일수록 자녀의 수에 크게 부정적인 영향을 미치게 됨을 확인할 수 있었다. 즉, 사회적으로 여성에게 경제활동의 참여를 적극적으로 권장하지만, 여전히 양육은 여성의 책임이라고 생각하는 경우에 저출산의 문제가 발생할 확률이 높은 것으로 나타났다. 이러한 결과를 바탕으로 저출산의 문제는 여성 개인의 선택이 아니라 사회적으로 일과 가정에서 이중적인 성평등주의적 관점이 적용됨에 따라 발생할 수 있음을 확인하였으며 저출산 현상에 대응하는 정책적 함의를 도출하였다. Women’s preference is significant for explaining fertility behavior, but women’s fertility decision is determined within the contexts of social norms on gender roles in a society where she lives. This research aims to investigate how women’s attitudes and social norms toward gender roles affect fertility behavior collectively by using the International Social Survey Programme 2012 in 26 OECD low fertility countries. We make gender role attitude indices for two different roles; instrumental roles measuring gender equity in economic activity participation and nurturant roles measuring gender equity in family. Empirical results indicate that women who possess contradictory gender role attitudes(e.g. egalitarian regarding instrumental roles but traditional regarding nurturant roles) are most likely to have fewer children. Similar results are found in terms of social norms on gender roles, and the effects of social norms have larger impacts than individual attitudes. The results suggest that the dynamics and variety of individual attitudes and social norms should be taken into account in fertility research.

최신 원격탐사 기법을 이용한 지구환경 모니터링 및 예측

박선영 ( Seonyoung Park ),송아람 ( Ahram Song ),이양원 ( Yangwon Lee ),임정호 ( Jungho Im ) 대한원격탐사학회 2023 大韓遠隔探査學會誌 Vol.39 No.5

인공위성의 발전과 함께 초소형 위성, 레이더 위성 등 이전보다 높은 시공간 해상도와 분광 해상도를 제공하는 위성들이 많아지고 있다. 이전에는 국가 단위의 위성개발이 주를 이루었지만 최근에는 민간기업에서도 위성을 개발하고 활용하는 연구들을 꾸준히 진행하고 있다. 본 특별호에서는 우리나라에서 수행되는 최신 원격탐사 기법 기반의 지구환경 분석에 대한 연구 및 기술개발 동향을 확인할 수 있다. 연구결과를 통해 추후 위성센서 개발을 위한 기초자료가 될 수 있으며 인공지능을 이용하는 연구자들에게 도메인에 대한 연구정보를 제공할 수 있다. 이번 특별호에서는 최신 원격탐사 기법을 데이터를 이용하여 지구환경을 모니터링하고 예측하는 연구들에 대한 소개를 중심으로 최근 원격탐사 분야의 기술 동향을 안내한다. 이를 통해 앞으로 원격탐사 분야에서 나아가야 할 방향을 확인하고자 한다.