Advances in the ECe prediction from EC1:5

박서우,최우정,백누리,신은서 한국토양비료학회 2024 한국토양비료학회지 Vol.57 No.1

The standard measure of soil salinity is electrical conductivity (EC) of saturated soil paste extracts (ECe). However, measuring ECe is labor and time-consuming and the accuracy of ECe is dependent on individual skill. As an alternative, the electrical conductivity of the extracts of 1:5 soil:water ratio (EC1:5) is commonly used, and thus the conversion of EC1:5 to ECe is necessary for the practical use of EC1:5. Recently, a multiple regression model for the estimation of conversion factors (CF) using clay content and exchangeable sodium percentage (ESP) has been developed: CF = 7.179 - 0.084 × Clay + 1.096 × ln(ESP). In this study, the CF model was validated using unpublished data on EC (EC1:5 and ECe), clay content, and ESP that were obtained from 50 paddy fields (n = 100 including two depth) of five reclaimed tidelands located in the coastal areas of South Korea. The CFs ranged from 5.7 to 11.9, and the measured and predicted ECe were linearly correlated (r2 = 0.81, P < 0.001) with an error of 11.2%. Despite the potential errors, we suggest that converting ECe from EC1:5 using the CF model may be a feasible method for long-term monitoring of ECe with the consideration of the time and cost and inconsistent accuracy of ECe measurement as clay content and ESP are the basic soil monitoring parameters in saline soil survey projects.

ALOS-2 Stripmap-ScanSAR 위상간섭기법에서의 스펙트럼 분석 평가

박서우,정성우,홍상훈,Park, Seo-Woo,Jung, Seong-Woo,Hong, Sang-Hoon 대한원격탐사학회 2020 大韓遠隔探査學會誌 Vol.36 No.2

연안 충적층 지역은 토양침식, 지반침하 등 지질 재해와 태풍, 홍수 해양 재해에 노출되어 인명 또는 재산 피해의 위험에 취약하다. 지반 침하는 지표 물질이 지하로 이동하면서 지반의 점진적인 또는 급격한 침강이 발생하는 현상으로 지속적인 감시가 요구된다. 영상레이더 위상간섭기법 (Radar Interferometry)은 마이크로파 영역에서 관측된 위상정보를 이용하여 지형 변위를 정밀하게 관측할 수 있는 기술이다. Small BAseline Subset(SBAS) 기법은 최소 20장 이상의 영상레이더 자료를 사용하여 대상 지역에 대한 시계열 지표 변위를 정밀하게 분석할 수 있어 지반침하 감시에 유용하다. X- 또는 C-밴드에 비해 장파장인 L-밴드 영상레이더 자료는 긴밀도 유지에 보다 유리하여 지구과학용으로 적합하다. 하지만 L-밴드 ALOS-2 PALSAR-2은 전지구 관측 프로그램을 운영하고 있어 시계열 분석을 하기에 영상 획득이 충분하지 않을 수 있다. 관심 지역인 부산의 경우, Stripmap 영상은 11장으로서 SBAS 시계열 분석 기법을 적용하기에는 부족한 촬영 수이다. 일반적으로 동일한 모드의 영상 간 위상간섭기법의 적용이 가능하지만, 비슷한 관측 기하에서 관측한 Stripmap과 ScanSAR 영상을 이용한 위상간섭기법의 적용이 성공적으로 수행된 바 있다. 해당 지역의 ScanSAR 영상은 18장으로 Stripmap-ScanSAR 위상간섭기법을 적용하면 SBAS 기법을 이용한 향상된 시계열 분석이 가능하게 된다. 본 연구에서는 Gamma 소프트웨어를 이용하여 ALOS-2 PALSAR-2로부터 획득된 L-band 영상 자료에 대한 위상간섭기법 적용 가능여부를 평가하였다. Stripmap-ScanSAR 위상간섭기법 적용을 위해 이종 모드 관측 영상 사이의 chirp bandwidth와 pulse repetition frequency (PRF)의 차이를 고려한 영상레이더 자료 처리를 수행하였으며, radar carrier frequency의 차이 보정과 common band filtering 적용 여부에 따라 발생하는 위상간섭도의 품질을 분석하였다. Radar carrier frequency 차이 보정에 따른 위상간섭도의 긴밀도 변화는 크게 나타나지 않았으나, common band filtering으로 인해, 위상간섭도에서 azimuth 방향으로 주기적인 잡음과 전체적인 긴밀도 저하가 발생하였다. 따라서 Stripmap-ScanSAR 위상간섭기법을 적용하는 경우 두 관측 모드의 range와 azimuth 방향의 밴드 폭의 특성에 따라 주의 깊은 자료 처리가 요구된다. It is well known that alluvial sediment located in coastal region has been easily affected by geohazard like ground subsidence, marine or meteorological disasters which threaten invaluable lives and properties. The subsidence is a sinking of the ground due to underground material movement that mostly related to soil compaction by water extraction. Thus, continuous monitoring is essential to protect possible damage from the ground subsidence in the coastal region. Radar interferometric application has been widely used to estimate surface displacement from phase information of synthetic aperture radar (SAR). Thanks to advanced SAR technique like the Small BAseline Subset (SBAS), a time-series of surface displacement could be successfully calculated with a large amount of SAR observations (>20). Because the ALOS-2 PALSAR-2 L-band observations maintain higher coherence compared with other shorter wavelength like X- or C-band, it has been regarded as one of the best resources for Earth science. However, the number of ALOS-2 PALSAR-2 observations might be not enough for the SBAS application due to its global monitoring observation scenario. Unfortunately, the number of the ALOS-2 PALSAR-2 Stripmap images in area of our interest, Busan which located in the Southeastern Korea, is only 11 which is insufficient to apply the SBAS time-series analysis. Although it is common that the radar interferometry utilizes multiple SAR images collected from same acquisition mode, it has been reported that the ALOS-2 PALSAR-2 Stripmap-ScanSAR interferometric application could be possible under specific acquisition mode. In case that we can apply the Stripmap-ScanSAR interferometry with the other 18 ScanSAR observations over Busan, an enhanced time-series surface displacement with better temporal resolution could be estimated. In this study, we evaluated feasibility of the ALOS-2 PALSAR-2 Stripmap-ScanSAR interferometric application using Gamma software considering differences of chirp bandwidth and pulse repetition frequency (PRF) between two acquisition modes. In addition, we analyzed the interferograms with respect to spectral shift of radar carrier frequency and common band filtering. Even though it shows similar level of coherence regardless of spectral shift in the radar carrier frequency, we found periodic spectral noises in azimuth direction and significant degradation of coherence in azimuth direction after common band filtering. Therefore, the characteristics of spectral bandwidth in the range and azimuth direction should be considered cautiously for the ALOS-2 PALSAR-2 Stripmap-ScanSAR interferometry.

고속 측면 충돌 감지 알고리즘의 개발

박서우(Seo-Wook Park),김현태(Hyun-Tae Kim) 한국자동차공학회 2000 한국 자동차공학회논문집 Vol.8 No.3

간척지 토양 유기탄소 함량 분석 방법의 불확실성

박서우(Seo-Woo Park),백누리(Nuri Baek),신은서(Eun-Seo Shin),서보성(Bo-Seong Seo),김한용(Han-Yong Kim),최우정(Woo-Jung Choi) 한국토양비료학회 2023 한국토양비료학회 학술발표회 초록집 Vol.2023 No.10

수치표고모형 공간해상도에 따른 선구조 자동 추출 연구

박서우 ( Seo-woo Park ),김건일 ( Geon-il Kim ),신진호 ( Jin-ho Shin ),홍상훈 ( Sang-hoon Hong ) 대한원격탐사학회 2018 大韓遠隔探査學會誌 Vol.34 No.3

The lineament is a linear or curved terrain element to discriminate adjacent geological structures in each other. It has been widely used for analysis of geology, mineral exploration, natural disasters, and earthquake, etc. In the past, the lineament has been extracted using cartographic map or field survey. However, it is possible to extract more efficiently the lineament for a very wide area thanks to development of remote sensing technique. Remotely sensed observation by aircraft, satellite, or digital elevation model (DEM) has been used for visual recognition for manual lineament extraction. Automatic approaches using computer science have been proposed to extract lineament more objectively. In this study, we evaluate the characteristics of lineament which is automatically extracted with respect to difference of spatial resolution of DEM. We utilized two types of DEM: one is Shuttle Radar Topography Mission (SRTM) with spatial resolution of about 90 m (3 arc sec), and the other is the latest world DEM of TerraSAR-X add-on for Global DEM with 12 m spatial resolution. In addition, a global DEM was resampled to produce a DEM with a spatial resolution of 30 m (1 arc sec). The shaded relief map was constructed considering various sun elevation and solar azimuth angle. In order to extract lineament automatically, we used the LINE module in PCI Geomatica software. We found that predominant direction of the extracted lineament is about N15-25°E (NNE), regardless of spatial resolution of DEM. However, more fine and detailed lineament were extracted using higher spatial resolution of DEM. The result shows that the lineament density is proportional to the spatial resolution of DEM. Thus, the DEM with appropriate spatial resolution should be selected according to the purpose of the study.

중랑천에 서식하는 수조류와 하천에 설치된 모래톱, 거석수제의 필요성

우혁진(Hyeokjin Woo),박서현(Seohyeon Park),손혜령(Haeryeong Son),오승주(Seungju Oh),이시윤(Siyoon Lee),정훈 반려동물연구학회 2022 Animalia Vol.4 No.1

본 연구는 중랑천에 서식하는 수조류의 개체수를 파악하고 자연적으로 생기거나 인공적으로 만들어진 모래톱과 거석수제가 중랑천에 서식하고 있는 수조류에게 어떠한 도움을 주는지 알아보는 목적으로 수행되었다. 노원교(37°40’44”N, 127°03’02”E)부터 상계교(37°39’43”N, 127°03’04”E)까지, 상계교(37°39’42”N, 127°03’03”)부터 녹천교(37°38’45”N, 127°03’18”E)까지 하나의 조사 구역을 두 구역으로 나눈 뒤 총 3차례에 걸쳐, 구역 내에 서식하는 수조류와 관찰 당시 수조류의 위치, 행동 등을 조사하였다. 본 연구 결과, 대부분의 수조류가 모래톱과 거석수제에서 먹이 활동을 하거나 숙면을 취하고 있는 모습이 확인되었다. 따라서 수조류에게 있어 하천의 모래톱과 거석수제는 필수적인 것으로 판단된다. The purpose of this study was to identify the population of water birds living in Jungnangcheon Stream and to find out how naturally formed or artificially created sandbars and giant stones help water birds living in Jungnangcheon Stream. A total of three survey areas were investigated, divided into two areas, from Nowon Bridge (37°4044N, 127°0302E) to Sanggye Bridge (37°3943N, 127°0304E) to Nokcheon Bridge (37°3845N, 127°0318E). As a result of this study, it was confirmed that most water birds were feeding or sleeping well on sandbars and megaliths. Therefore, sandbars and megaliths of rivers are considered essential for water birds.

Hydrogenation of benzyl toluene using Ru/ZrO₂ catalysts: Interaction of zirconium hydroxide and Ru₃(CO)₁₂ precursor

김태완,박서우,조영인,서영웅 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.1

인체 유래 환경유해물질 노출에 따른 멀티 오믹스 데이터 통합 분석 가시화 시스템

신가희,홍지만,박서우,강병철,이봉문 한국멀티미디어학회 2022 멀티미디어학회논문지 Vol.25 No.2

Multi-omics data is difficult to interpret due to the heterogeneity of information by the volume of data, the complexity of characteristics of each data, and the diversity of omics platforms. There is not yet a system for interpreting to visualize research data on environmental diseases concerning environmental harmful substances. We provide MEE, a web-based visualization tool, to comprehensively explore the complexity of data due to the interconnected characteristics of high-dimensional data sets according to exposure to various environmental harmful substances. MEE visualizes omics data of correlation between omics data, subjects and samples by keyword searches of meta data, multi-omics data, and harmful substances. MEE has been demonstrated the versatility by two examples. We confirmed the correlation between smoking and asthma with RNA-seq and Methylation-Chip data, it was visualized that genes (PHACTR3, PXDN, QZMB, SOCS3 etc.) significantly related to autoimmune or inflammatory diseases. To visualize the correlation between atopic dermatitis and heavy metals, we selected 32 genes related immune response by integrated analysis of multi-omics data. However, it did not show a significant correlation between mercury in blood and atopic dermatitis. In the future, should continuously collect an appropriate level of multi-omics data in MEE system, will obtain data to analyze environmental substances and diseases.

양측성 전체 구치부의 협측 반대교합 환자의 하악 전진술을 동반한 교정치료

장우원,마수정,박서우,김종성,강윤구 대한치과교정학회 2020 대한치과교정학회 임상저널 Vol.10 No.3

Bilateral posterior buccal crossbite (bilateral Brodie bite) is a challenging case to orthodontists. Many case reports presented treatment modalities from relatively simple to complicated surgeries. These diversities in treatment method are mainly due to various conditions of the underlying cause of Brodie bite such as skeletal/dental or maxillary/mandibular problems. In this case report, a young adult with skeletal Class II relationship and Brodie bite was treated with orthodontic treatment and mandibular advancement surgery. Descriptions and discussions will be presented from the diagnosis to the treatment results and retention.

Evaluation of nutrient loading technique potential of domestic tree species to promote forestation

이승범,곽진협,오예림,백누리,박서우,신은서,최우정 한국토양비료학회 2024 한국토양비료학회지 Vol.57 No.1

Reclaimed lands, including reclaimed tidelands, usually have poor soil conditions, such as low nutrient and organic matter contents and poor soil structures, which hamper adaptation and survival of newly transplanted tree seedlings. Nutrient loading technique is the concept of accumulating more nutrient in plant parts while maintaining biomass, which can increase growth and survival rates after transplanting in nutrient poor soils. However, possibility of nutrient loading on domestic tree species has not been evaluated in Korea. This study was conducted to test and select the optimum nutrient loading models for domestic tree species. Three nutrient loading models, including conventional (constant fertilizer dose), exponential (increasing fertilizer dose as exponential curve), and modified exponential (exponential increase but compensate initial fertilization), were tested for three tree species; Pinus thunbergii, Quercus acutissima, and Zelkova serrata. Seedlings were grown in a greenhouse from June to September in 2020, and selected amount of fertilizer was applied weekly. Three seedlings were collected randomly every 4 weeks in each tree species and nutrient loading model, and dry matter and nitrogen (N) concentration in each part, including root, stem, and leaf, were analyzed, and seeding height was measured. Seedling height was not different with nutrient loading models for all tree species. For P. thunbergii, dry matter and N content were the highest with the conventional and modified exponential models, and for Q. acutissima and Z. serrata, the modified exponential model was the best. The modified exponential model resulted in the highest nutrient loading efficiency due to the compensation of N supply at the beginning of growing stage and the higher N supply rates at the late growing stage compared to the conventional model. However, survival rate of seedlings for exponential model decreased after middle growing stage because of toxicity of excessive N fertilization due to rapid supply of N. Therefore, diverse rate of N fertilization needs to be tested to select the optimum nutrient loading models for each species. Furthermore, field study is needed to test if nutrient loaded seedings grow better than conventional seedlings at poor soil condition lands.