Evaluation of GSICS Correction for COMS/MI Visible Channel Using S-NPP/VIIRS

( Donghyun Jin ),( Soobong Lee ),( Seonyoung Lee ),( Daeseong Jung ),( Suyoung Sim ),( Morang Huh ),( Kyung-soo Han ) 대한원격탐사학회 2021 大韓遠隔探査學會誌 Vol.37 No.1

The Global Space-based Inter-Calibration System (GSICS) is an international partnership sponsored by World Meteorological Organization (WMO) to continue and improve climate monitoring and to ensure consistent accuracy between observation data from meteorological satellites operating around the world. The objective for GSICS is to inter-calibration from pairs of satellites observations, which includes direct comparison of collocated Geostationary Earth Orbit (GEO)-Low Earth Orbit (LEO) observations. One of the GSICS intercalibration methods, the Ray-matching technique, is a surrogate approach that uses matched, co-angled and colocated pixels to transfer the calibration from a well calibrated satellite sensor to another sensor. In Korea, the first GEO satellite, Communication Ocean and Meteorological Satellite (COMS), is used to participate in the GSICS program. The National Meteorological Satellite Center (NMSC), which operated COMS/MI, calculated the Radiative Transfer Model (RTM)-based GSICS coefficient coefficients. The L1P reproduced through GSICS correction coefficient showed lower RMSE and Bias than L1B without GSICS correction coefficient applied. The calculation cycles of the GSICS correction coefficients for COMS/MI visible channel are provided annual and diurnal (2, 5, 10, 14-day), but long-term evaluation according to these cycles was not performed. The purpose of this paper is to perform evaluation depending on the annual/diurnal cycles of COMS/MI GSICS correction coefficients based on the ray-matching technique using Suomi-NPP/Visible Infrared Imaging Radiometer Suite (VIIRS) data as reference data. As a result of evaluation, the diurnal cycle had a higher coincidence rate with the reference data than the annual cycle, and the 14-day diurnal cycle was the most suitable for use as the GSICS correction coefficient.

11 μm 휘도온도와 11-12 μm 휘도온도차의 상관성 분석을 활용한 해빙탐지 동적임계치 결정

진동현 ( Donghyun Jin ),이경상 ( Kyeong-sang Lee ),최성원 ( Sungwon Choi ),서민지 ( Minji Seo ),이다래 ( Darae Lee ),권채영 ( Chaeyoung Kwon ),김홍희 ( Honghee Kim ),이은경 ( Eunkyung Lee ),한경수 ( Kyung-soo Han ) 대한원격탐사학회 2017 大韓遠隔探査學會誌 Vol.33 No.2

지구 기후시스템의 중요구성인자인 해빙은 극지방과 고위도에 분포하는 특성상 위성을 통한 탐지가 활발히 수행되고 있다. 위성자료를 이용한 해빙탐지기법은 반사도와 휘도온도자료를 이용하며, 많은 연구에서 휘도온도자료를 통해 산출된 Ice Surface Temperature (IST)를 활용한 기법인 Moderate-Resolution Imaging Spectroradiometer (MODIS)의 해빙탐지기법을 활용하고 있다. 본 연구에서는 IST산출과정이 생략된 단순하고 효율적인 동적임계값 기법을 활용한 해빙탐지기법을 제시하고자 한다. 동적임계값을 지정하기 위하여 해수의 어는점 이하의 화소를 대상으로 MODIS IST와 MODIS 11μm 채널의 휘도 온도, Brightness Temperature Difference (BTD: T_11μm-T_12μm)의 상호관계를 분석하였다. 분석 결과, 세수치의 관계가 선형의 특징을 나타내었으며 이를 활용하여 임계값을 지정하였다. 청천역에서 지정한 임계값을 MODIS 11 μm 채널에 적용하여 해빙을 탐지하였다. 또한, 본 연구의 해빙탐지기법의 성능을 검증하기 위해 MODIS Sea ice extent를 이용하여 정확도를 분석하였으며 그 결과, Producer Accuracy (PA) 99%이상의 높은 정확도를 보였다. Sea ice which is an important component of the global climate system is being actively detected by satellite because it have been distributed to polar and high-latitude region. and the sea ice detection method using satellite uses reflectance and temperature data. the sea ice detection method of Moderate-Resolution Imaging Spectroradiometer (MODIS), which is a technique utilizing Ice Surface Temperature (IST) have been utilized by many studies. In this study, we propose a simple and effective method of sea ice detection using the dynamic threshold technique with no IST calculation process. In order to specify the dynamic threshold, pixels with freezing point of MODIS IST of 273.0 K or less were extracted. For the extracted pixels, we analyzed the relationship between MODIS IST, MODIS 11μm channel brightness temperature(T_11μm) and Brightness Temperature Difference (BTD: _T11μm-T_12μm). As a result of the analysis, the relationship between the three values showed a linear characteristic and the threshold value was designated by using this. In the case of sea ice detection, if T₁₁ μm is below the specified threshold value, it is detected as sea ice on clear sky. And in order to estimate the performance of the proposed sea ice detection method, the accuracy was analyzed using MODIS Sea ice extent and then validation accuracy was higher than 99% in Producer Accuracy (PA).

원발개방각녹내장에서 추적관찰 주기에 따른 비용효용분석

최진아(Jin A Choi),권진우(Jin Woo Kwon),지동현(Donghyun Jee) 대한안과학회 2018 대한안과학회지 Vol.59 No.9

목적: 녹내장의 추적관찰 주기와 녹내장의 진행 정도의 정량적 관계에 기초한 비용효용분석을 시행하고자 하였다. 대상과 방법: Markov 모델을 구축하여 초기 녹내장을 가지고 있는 40세 이상의 한국인 남녀를 가상의 코호트로 설정하였다. 녹내장 치료 관련 비용을 사회적인 관점에서 파악하였으며, 효용은 녹내장 상태에 따른 질보정수명을 산출하였다. 녹내장 건강상태는 5단계로 나누었다(초기, 중기, 후기, 단안실명, 양안실명). 녹내장 상태의 전이는 경도에서 중등도로 한 방향으로만 전이하는 것으로 하였고, 각 한 주기의 길이는 1년으로 설정하였다. 비용효용의 점진적 증가비율을 계산하여 추적관찰 주기에 따른 비용효용을 비교하였다. 민감도 분석을 시행하여 본 연구에서 사용한 변수의 불확실성이 어떻게 결과에 영향을 주는지를 파악하였다. 결과: 3개월 추적관찰의 점진적 비용효용비는 6개월의 추적관찰 대비 질보정수명당 28,244,398원이며, 6개월 추적관찰의 점진적 비용효용비는 12개월 추적관찰 대비 질보정수명당 13,615,443원으로 나타났다. 3개월 대비 6개월 주기 추적관찰의 진행확률이 약 10% 이상 증가하고, 3개월 대비 12개월 추적관찰의 진행확률이 약 15% 이상 증가하는 경우에는 3개월 주기 추적관찰이 비용효과적인 것으로 나타났다. 반면, 3개월 대비 6개월 추적관찰의 진행확률의 증가폭이 10% 미만이고, 3개월 대비 12개월 추적관찰의 진행확률이 15% 이상 증가할 경우 6개월 추적관찰이 비용효과적인 것으로 나타났다. 3개월 대비 6개월 추적관찰 전략의 진행확률 증가폭이 10% 를 넘고, 3개월 대비 12개월 추적관찰의 진행확률 증가폭이 15% 미만이면 12개월 추적관찰이 비용효과적인 것으로 나타났다. 결론: 본 연구에서 녹내장의 진행확률에 따라 비용효과적인 추적관찰의 전략이 다르며, 3개월 또는 6개월의 추적관찰 전략이 비용효 과적이며 우리나라의 의료보건체계에서 받아들일 수 있는 정도인 것으로 나타났다. <대한안과학회지 2018;59(9):842-847> Purpose: To evaluate the cost-utility based on the quantitative relationship between glaucoma follow-up and glaucoma progression. Methods: The Markov model was constructed and analyzed to determine the cost-effectiveness of primary open-angle glaucoma. The Markov model set up a virtual cohort of Korean over 40 years of age with early glaucoma. The costs associated with glaucoma treatment were assessed from a social point of view, and the utility was calculated using the quality adjusted life years according to the glaucoma states. Glaucoma health status was divided into 5 stages (early, middle, late, unilateral, bilateral blindness). The transition probability was set in one direction from mild to severe, and the length of each cycle was set at one year. The incremental cost effectiveness ratio (ICER) was calculated and compared with each other different follow-up periods. Sensitivity analysis was conducted to determine how the uncertainty of the variables used in this study affected the outcome. Results: ICER of 3-month follow-up was 28,244,398 won/quality adjusted life years (QALY) compared 6-month follow-up, and ICER of 6-month follow-up was 13,615,443 won/QALY compared to 12-month follow-up. If the probability of progression of glaucoma in 6-months follow-up observations increases by more than 10% over 3-month periodic follow-up and the progression probability of 12-month follow-up increases by more than 15% follow-up compared to 3-months follow-up, 3-months follow-up was found to be a cost-effective strategy. On the other hand, 6-month follow-up was found to be cost-effective if probability of progression of 6-month follow-up was less than 10% increase of 3-month follow-up and 15% increase of 6-months follow-up. Conclusions: Cost-effective follow-up strategies differed according to the probability of progression of glaucoma, and 3-month or 6-month follow-up strategies were cost-effective and acceptable in Korea s health care system. J Korean Ophthalmol Soc 2018;59(9):842-847

Cost-utility Analysis of Primary Open-angle Glaucoma according to Follow-up Observation Period

Choi, Jin A,Kwon, Jin Woo,Jee, Donghyun Korean Opthalmological Society 2018 대한안과학회지 Vol.59 No.9

A Fast Chirp 15-17GHz FMCW Frequency Synthesizer with Phase Rotator

Seung Jin Moon,Kwang-Il Oh,Goo-Han Ko,Zhenbo Jin,Yujin Kyung,Donghyun Baek 대한전자공학회 2023 대한전자공학회 학술대회 Vol.2023 No.6

Injectable hydrogel composite containing modified gold nanoparticles: implication in bone tissue regeneration

Lee, Donghyun,Heo, Dong Nyoung,Nah, Ha Ram,Lee, Sang Jin,Ko, Wan-Kyu,Lee, Jae Seo,Moon, Ho-Jin,Bang, Jae Beum,Hwang, Yu-Shik,Reis, Rui L,Kwon, Il Keun Dove Medical Press 2018 International journal of nanomedicine Vol.13 No.-

<P><B>Background</B></P><P>For effective bone regeneration, it is necessary to implant a biocompatible scaffold that is capable of inducing cell growth and continuous osteogenic stimulation at the defected site. Here, we suggest an injectable hydrogel system using enzymatic cross-linkable gelatin (Gel) and functionalized gold nanoparticles (GNPs).</P><P><B>Methods</B></P><P>In this work, tyramine (Ty) was synthesized on the gelatin backbone (Gel-Ty) to enable a phenol crosslinking reaction with horseradish peroxidase (HRP). N-acetyl cysteine (NAC) was attached to the GNPs surface (G-NAC) for promoting osteodifferentiation.</P><P><B>Results</B></P><P>The Gel-Ty hydrogels containing G-NAC (Gel-Ty/G-NAC) had suitable mechanical strength and biocompatibility to embed and support the growth of human adipose derived stem cells (hASCs) during a proliferation test for three days. In addition, G-NAC promoted osteodifferentiation both when it was included in Gel-Ty and when it was used directly in hASCs. The osteogenic effects were demonstrated by the alkaline phosphatase (ALP) activity test.</P><P><B>Conclusion</B></P><P>These findings indicate that the phenol crosslinking reaction is suitable for injectable hydrogels for tissue regeneration and G-NAC stimulate bone regeneration. Based on our results, we suggest that Gel-Ty/G-NAC hydrogels can serve both as a biodegradable graft material for bone defect treatment and as a good template for tissue engineering applications such as drug delivery, cell delivery, and various tissue regeneration uses.</P>

The cost-effectiveness of medication, laser trabeculoplasty, and trabeculectomy for treatment of open-angle glaucoma in South Korea

Choi, Jin A.,Song, Lina D.,Choi, Seulggie,Park, Sang Min,Kwon, Jin Woo,Jee, Donghyun Williams & Wilkins Co 2019 Medicine Vol.98 No.2

<P><B>Abstract</B></P><P><B>Objectives:</B></P><P>Open-angle glaucoma (OAG) imposes high disease burden in South Korea. Although various effective interventions are available to manage the progression of OAG, there is limited data on the cost-effectiveness of these treatment strategies in South Korea.</P><P><B>Methods:</B></P><P>Using a Markov cohort model, we evaluated the cost-effectiveness of 3 major treatment strategies (medication, laser trabeculoplasty, and trabeculectomy) for South Korean patients with OAG. We projected a 25-year time horizon to study a hypothetical cohort of 10,000 patients of age 40 with mild OAG. The outcome measures were quality-adjusted life-years (QALYs) gained, cost from the societal perspective, and the incremental cost-effectiveness ratio (ICER) of medication, laser trabeculoplasty, and trabeculectomy. Interventions were evaluated at a willingness-to-pay (WTP) threshold of 30,000,000 KRW ($29,152) per QALY gained. Deterministic and probabilistic sensitivity analyses were conducted to address the model uncertainty.</P><P><B>Results:</B></P><P>The mean costs for medication, laser trabeculoplasty, and trabeculectomy were 29,661,740 KRW, 17,34,1342 KRW, and 22,275,438 KRW, respectively. The mean QALYs gained were 15.7, 15.3, and 14.8 for medication, laser trabeculoplasty, and trabeculectomy, respectively. Surgery was strongly dominated because it generated fewer expected QALYs but incurred greater expected cost than laser. The ICER was 30,885,179 KRW per QALY for medication versus laser trabeculoplasty. Laser was cost-effective, however, at a lower WTP threshold of 21,000,000 KRW per QALY gained or below. The results were most sensitive to the progression rates from mild to moderate glaucoma under laser treatment.</P><P><B>Conclusion:</B></P><P>Under the WTP threshold of 30,000,000 KRW per QALY, medication was cost-effective compared with laser trabeculoplasty and trabeculectomy for treating mild OAG in South Korean population. Laser, however, can be a cost-effective alternative in more resource-limited settings.</P>

The use of heparin chemistry to improve dental osteogenesis associated with implants

Lee, Sang Jin,Bae, Min Soo,Lee, Deok Won,Heo, Dong Nyoung,Lee, Donghyun,Heo, Min,Hong, Seoung-Jin,Kim, Joohyoung,Kim, Wan Doo,Park, Su A,Kwon, Il Keun Elsevier 2017 Carbohydrate polymers Vol.157 No.-

<P><B>Abstract</B></P> <P>In this study, we designed a hybrid Ti by heparin modifying the Ti surface followed by Growth/differentiation factor-5 (GDF-5) loading. After that, products were characterized by physicochemical analysis. Quantitative analysis of functionalized groups was also confirmed. The release behavior of GDF-5 grafted samples was confirmed for up to 21days. The surface modification process was found to be successful and to effectively immobilize GDF-5 and provide for its sustained release behavior. As an <I>in vitro</I> test, GDF-5 loaded Ti showed significantly enhanced osteogenic differentiation with increased calcium deposition under nontoxic conditions against periodontal ligament stem cells (PDLSc). Furthermore, an <I>in vivo</I> result showed that GDF-5 loaded Ti had a significant influence on new bone formation in a rabbit model. These results clearly confirmed that our strategy may suggest a useful paradigm by inducing osseo-integration as a means to remodeling and healing of bone defects for restorative procedures in dentistry.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Titanium surface was developed to selectively graft the polymer using bioactive chemistry. </LI> <LI> The developed hybrid titanium disc showed outstanding <I>in vitro</I> osteo-integration activities. </LI> <LI> The surface modified titanium implant exhibited significant bone tissue regeneration in a rabbit model. </LI> </UL> </P>

Prediction of Clogging sediment in offline Detention Storage System with Numerical Particle Tracking Method

DongHyun Kim,Hyungju Yoo,Seung-Jin Maeng,Seungoh Lee 한국콘텐츠학회 2018 한국콘텐츠학회 ICCC 논문집 Vol.2018 No.12

Temperature effect of SnSe nanofibers fabricated by electrospinning

Donghyun Kim,Juyun Park,Jihyeon Lee,Dongwoo Kim,Jin-Woo Oh,Yong-Cheol Kang 한국진공학회 2021 한국진공학회 학술발표회초록집 Vol.2021 No.2

SnSe has been studied as optoelectronic devices due to its several advantages such as earth-abundant and ultralow thermal conductivity. Also, nanofiber (NF) is one of the most striking materials due to high surface to volume ratio. We fabricated SnSe NFs by electrospinning method and calcined at various temperature to investigate temperature effect. The surface morphology and atomic compositional ratio of NFs were studied by SEM and EDX mapping. The crystallinity and phase of NFs were investigated using XRD. To study the compositional ratio and chemical environment of NFs, we performed XPS.