• Title/Summary/Keyword: High resolution studies

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Active Fire Detection Using Landsat 8 OLI Images: A Case of 2019 Australia Fires (Landsat 8 OLI 영상을 이용한 산불탐지: 2019년 호주 산불을 사례로)

  • Kim, Nari;Lee, Yangwon
    • Korean Journal of Remote Sensing
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    • v.36 no.5_1
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    • pp.775-784
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    • 2020
  • Recent global warming and anthropogenic activities have caused more frequent and massive wildfires with longer durations and more significant damages. MODIS has been monitoring global wildfires for almost 20 years, and GK2A and Himawari-8 are observing the wildfires in East Asia 144 times a day. However, the spatial resolution of 1 to 2 km is not sufficient for the detection of small and medium-size active fires, and therefore the studies on the active fire detection using high-resolution images are essential. However, there is no official product for the high-resolution active fire detection. Hence, we implemented the active fire detection algorithm of Landsat 8 and carried out a high-resolution-based detection of active fires in Australia in 2019, followed by the comparisons with the products of Himawari-8 and MODIS. Regarding the intense fires, the three satellites showed similar results, whereas the weak igniting and extinguishing fires or the fires in narrow areas were detected by only Landsat 8 with a 30m resolution. Small-sized fires, which are the majority in Korea, can be detected by the high-resolution satellites such as Landsat 8, Sentinel-2, Kompsat-3A, and the forthcoming Kompsat-7. Also, a comprehensive analysis together with the geostationary satellites in East Asia such as GK2A, Himawari-8, and Fengyun-3 will help the interoperability and the improvement of spatial and temporal resolutions.

Simulation and Experimental Studies of Super Resolution Convolutional Neural Network Algorithm in Ultrasound Image (초음파 영상에서의 초고분해능 합성곱 신경망 알고리즘의 시뮬레이션 및 실험 연구)

  • Youngjin Lee
    • Journal of the Korean Society of Radiology
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    • v.17 no.5
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    • pp.693-699
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    • 2023
  • Ultrasound is widely used in the medical field for non-destructive and non-invasive disease diagnosis. In order to improve the disease diagnosis accuracy of diagnostic medical images, improving spatial resolution is a very important factor. In this study, we aim to model the super resolution convolutional neural network (SRCNN) algorithm in ultrasound images and analyze its applicability in the medical diagnostic field. The study was conducted as an experimental study using Field II simulation and open source clinical liver hemangioma ultrasound imaging. The proposed SRCNN algorithm was modeled so that end-to-end learning can be applied from low resolution (LR) to high resolution. As a result of the simulation, we confirmed that the full width at half maximum in the phantom image using a Field II program was improved by 41.01% compared to LR when SRCNN was used. In addition, the peak to signal to noise ratio (PSNR) and structural similarity index (SSIM) evaluation results showed that SRCNN had the excellent value in both simulated and real liver hemangioma ultrasound images. In conclusion, the applicability of SRCNN to ultrasound images has been proven, and we expected that proposed algorithm can be used in various diagnostic medical fields.

Effect of Marital Conflict on Adolescent Anxiety: The Mediating Role of Parentification (부부갈등이 청소년의 불안에 미치는 영향: 청소년 부모화의 매개적 역할)

  • Yang, Han-Na;Choi, Mi-Kyung
    • Korean Journal of Child Studies
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    • v.38 no.3
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    • pp.49-63
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    • 2017
  • Objective: The main purpose of this study was to examine the relationship between marital conflict, parentification, and adolescent anxiety. Methods: The participants comprised 301 high school students from the Seoul province. They were asked to complete questionnaires that consisted of the State-Trait Anxiety Inventory, the Children's Perception of Interparental Conflict Scale, and the Filial Responsibility Scale-Youth. The data were analyzed by frequency analysis, Cronbach's ${\alpha}$, descriptive statistical analysis, Pearson's correlation coefficients, multiple regression analysis, and hierarchical multiple regression analysis. To analyze the collected data, SPSS 18.0 was used. Results: First, the content and resolution of marital conflict had an effect on both adolescent state anxiety and trait anxiety. Second, unfairness parentification had an effect on both adolescent state anxiety and trait anxiety. Third, the frequency of marital conflict had an effect on emotional parentification. Further, the intensity, content, and resolution of marital conflict had effect on unfairness parentification. Fourth, unfairness parentification played a partial mediating role in the relationship between the content of marital conflict and adolescent anxiety (state anxiety/trait anxiety). In addition, unfairness parentification played a complete mediating role in the relationship between the resolution of marital conflict and adolescent trait anxiety. Conclusion: These results indicate that parentification plays an important role in marital conflict and adolescent anxiety. In addition, this study also shows that marital conflict has an important effect on adolescent anxiety directly. Therefore, this study will be useful for developing both parental education and counseling programs for adolescents.

1/10,000 Scale Digital Mapping using High Resolution Satellite Images (고해상도 위성영상을 이용한 축척 1/10,000 수치지도 제작)

  • Lee, Byung-Hwan;Kim, Jeong-Hee;Park, Kyung-Hwan;Chung, Il-Hoon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.3 no.2
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    • pp.11-23
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    • 2000
  • The subjects of this study are to examine and to apply the methods of making 1 : 10,000 scale digital maps using Russian's 2 m resolution satellite images of Alternative and 8 m resolution stereo satellite images of MK-4 for the Kyoha area of Paju-city where aerial-photo surveying is not possible. A digital elevation model (DEM) was calculated from MK-4 images. With this DEM, the Alternative images were orthorectified. Ground control points (GCP) were acquired from GPS surveyings and were used to perform geometric corrections on Alternative images. From field investigation, thematic attributes are digitized on the monitor. RMS errors of the planar and vertical positions are estimated to ${\pm}0.4$ m and ${\pm}15$ m, respectively. The planar accuracy is better than an accuracy required by NGIS (national GIS) programs. Local information from field investigation was added and the resulting maps should be good as base maps for, such as, regional and urban plannings.

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HIGH ANGULAR RESOLUTION [Fe II] λ1.644 μ SPECTROSCOPY OF YSOS WITH SUBARU TELESCOPE

  • PYO TAE-SOO;HAYASHI MASAHIKO;NAOTO KOBAYASHI;TERADA HIROSHI;TOKUNAGA ALAN T.
    • Journal of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.249-252
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    • 2005
  • We present results of the velocity-resolved spectroscopy of the [Fe II] $\lambda$1.644${\mu}m$ emission toward outflow sources with the Subaru Telescope at the angular resolution of 0.apos;16 ${\~}$ 0.apos;5 arcseconds. The observed sources are L1551 IRS 5, DG Tau, HL Tau and RW Aur, which are located in the Taurus-Aurigae Molecular Cloud, one of the closest star forming regions (0.apos;1 = 14 AU). We were able to resolve outflow structure in the vicinity of the sources at a scale of a few tens of AU. The position-velocity diagram of each object shows two velocity components: the high velocity component (HVC: 200 - 400 km $s^{-l}$) and the low velocity component (LVC: 50 - 150 km $s^{-l}$), which are clearly distinct in space and velocity. The HVC may be a highly collimated jet presumed from its narrow velocity width and high velocity. The LVC, on the other hand, may be a widely opened disk wind inferred from its broad velocity width and low velocity. The spectrum taken perpendicular to the L1551 IRS 5 outflow at its base shows that the LVC has a spatially wide subcomponent, supporting the above interpretation. We demonstrated that the [Fe II] 1.644 $\mu$ spectroscopy is a very powerful tool for the studies of fast jets and winds that directly emanate from star-disk systems.

DEM Generation from IKONOS Imagery by Using Parallel Projection Model (평행투영모형에 의한 IKONOS 위성영상의 수치고도모형 생성)

  • Kim, Eui-Myoung;Kim, Seong-Sam;Yoo, Hwan-Hee
    • Journal of Korean Society for Geospatial Information Science
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    • v.13 no.1 s.31
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    • pp.55-61
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    • 2005
  • Digital Elevation Model (DEM) generation from remotely sensed imagery is crucial for a variety of mapping applications such as ortho-photo generation, city modeling. High resolution imaging satellites such as SPOT-5, IKONOS, QUICK-BIRD, ORBVIEW constitute an excellent source for efficient and economic generation of DEM data. However, prerequisite knowledge in the areas of sensor modeling, epipolar resampling, and image matching is required to generate DEM from these high resolution satellite imagery. From the above requirements, epipolar resampling emerges as the most important factors. Research attempts in this area are still in high demand and short supply. Another cause that adds to the complication of the problem is that most studies of DEM generation from IKONOS scenes have been based on rational function model. In this paper, we proposed a new methodology for DEM generation from satellite scenes using parallel projection model which is sensor independent, makes it possible for sensor modeling and epipolar resampling by only few control points. The performance and feasibility of the developed methodology is evaluated through real dataset captured by IKONOS.

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High Spatial Resolution Satellite Image Simulation Based on 3D Data and Existing Images

  • La, Phu Hien;Jeon, Min Cheol;Eo, Yang Dam;Nguyen, Quang Minh;Lee, Mi Hee;Pyeon, Mu Wook
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.34 no.2
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    • pp.121-132
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    • 2016
  • This study proposes an approach for simulating high spatial resolution satellite images acquired under arbitrary sun-sensor geometry using existing images and 3D (three-dimensional) data. First, satellite images, having significant differences in spectral regions compared with those in the simulated image were transformed to the same spectral regions as those in simulated image by using the UPDM (Universal Pattern Decomposition Method). Simultaneously, shadows cast by buildings or high features under the new sun position were modeled. Then, pixels that changed from shadow into non-shadow areas and vice versa were simulated on the basis of existing images. Finally, buildings that were viewed under the new sensor position were modeled on the basis of open library-based 3D reconstruction program. An experiment was conducted to simulate WV-3 (WorldView-3) images acquired under two different sun-sensor geometries based on a Pleiades 1A image, an additional WV-3 image, a Landsat image, and 3D building models. The results show that the shapes of the buildings were modeled effectively, although some problems were noted in the simulation of pixels changing from shadows cast by buildings into non-shadow. Additionally, the mean reflectance of the simulated image was quite similar to that of actual images in vegetation and water areas. However, significant gaps between the mean reflectance of simulated and actual images in soil and road areas were noted, which could be attributed to differences in the moisture content.

Proposed Survey Steps for Investigation of Land-Creeping Susceptibility Areas: A Focus on Geophysical Mapping of the Yongheung-dong, Pohang, Korea

  • Kim, Jeong-In;Lee, Sun-Joong;Kim, Kwan-Soo;Lee, Jae-Eun;Sa, Jin-Hyun;Kim, Ji-Soo
    • The Journal of Engineering Geology
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    • v.31 no.3
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    • pp.269-281
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    • 2021
  • Land creeping is the imperceptibly slow, steady, downward movement o f slope-forming soil or rock. Because creep-related failures occur frequently on a large scale without notice, they can be hazardous to both property and human life. Korea Forest Service has operated the prevention and response system from land creeping which has been on the rise since 2018. We categorized and proposed three survey steps (e.g., preliminary, regional, detailed) for investigation of creeping susceptibility site with a focus on geophysical mapping of a selected test site, Yongheung-dong, Pohang, Korea. The combination of geophysical (dipole-dipole electrical resistivity tomography and reciprocal seismic refraction technique, well-logging), geotechnical studies (standard penetrating test, laboratory tests), field mapping (tension cracks, uplift, fault), and comprehensive interpretation of their results provided the reliable information of the subsurface structures including the failure surface. To further investigate the subsurface structure including the sliding zone, we performed high-resolution geophysical mapping in addition to the regional survey. High-resolution seismic velocity structures are employed for stability analysis because they provided more simplified layers of weathering rock, soft rock, and hard rock. Curved slip plane of the land creeping is effectively delineated with a shape of downslope sliding and upward pushing at the apex of high resistive bedrock in high-resolution electrical resistivity model with clay-mineral contents taken into account. Proposed survey steps and comprehensive interpretation schemes of the results from geological, geophysical, and geotechnical data should be effective for data sets collected in a similar environment to land-creeping susceptibility area.

Building Height Extraction using Triangular Vector Structure from a Single High Resolution Satellite Image (삼각벡터구조를 이용한 고해상도 위성 단영상에서의 건물 높이 추출)

  • Kim, Hye-Jin;Han, Dong-Yeob;Kim, Yong-Il
    • Korean Journal of Remote Sensing
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    • v.22 no.6
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    • pp.621-626
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    • 2006
  • Today's commercial high resolution satellite imagery such as IKONOS and QuickBird, offers the potential to extract useful spatial information for geographical database construction and GIS applications. Extraction of 3D building information from high resolution satellite imagery is one of the most active research topics. There have been many previous works to extract 3D information based on stereo analysis, including sensor modelling. Practically, it is not easy to obtain stereo high resolution satellite images. On single image performance, most studies applied the roof-bottom points or shadow length extracted manually to sensor models with DEM. It is not suitable to apply these algorithms for dense buildings. We aim to extract 3D building information from a single satellite image in a simple and practical way. To measure as many buildings as possible, in this paper, we suggested a new way to extract building height by triangular vector structure that consists of a building bottom point, its corresponding roof point and a shadow end point. The proposed method could increase the number of measurable building, and decrease the digitizing error and the computation efficiency.

The Development and Application of Chirotechnology Using Chiral Crown Ethers for Enantiomer Separation (광학분리를 위한 키랄 크라운 에테르를 이용한 키랄공학의 개발과 응용)

  • Paik, Man-Jeong;Yun, Won-Nam;Lee, Won-Jae
    • KSBB Journal
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    • v.27 no.4
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    • pp.199-206
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    • 2012
  • Chiral crown ethers are synthetic macrocyclic polyethers that bind protonated chiral primary amines with high selectivity and affinity. They have been widely used to separate or distinguish the enantiomers of chiral compounds containing a primary amino moiety by high-performance liquid chromatography, capillary electrophoresis, and NMR spectroscopy. In this paper, two important chiral crown ethers including chiral binaphthyl unit and (18-crown-6)-2,3,11,12-tetracarboxylic acid as chiral selectors are focused. And several chiral resolution techniques and their applications in chirotechnology using these chiral crown ethers with related chiral recognition mechanism studies are reviewed. Especially, it was shown that the commercially available HPLC columns based on (18-crown-6)-2,3,11,12-tetracarboxylic acid have been developed and successfully applied for the resolution of various primary amino compounds including amino acids.