• Title/Summary/Keyword: Photographs

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Analysis of Debris Flow Hazard Zone by the Optimal Parameters Extraction of Random Walk Model - Case on Debris Flow Area of Bonghwa County in Gyeongbuk Province - (Random Walk Model의 최적 파라미터 추출에 의한 토석류 피해범위 분석 - 경북 봉화군 토석류 발생지를 대상으로 -)

  • Lee, Chang-Woo;Woo, Choongshik;Youn, Ho-Joong
    • Journal of Korean Society of Forest Science
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    • v.100 no.4
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    • pp.664-671
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    • 2011
  • Random Walk Model can predict the sediment areas of debris flow but it must be extracted three parameters fitted topographical environment. This study developed the method to extract the optimal values of three parameters - Once flowing volume, Stopping slope and Gravity weight - for Random Walk Model. And the extracted parameters were validated by aerial photographs of the debris flowed area. To extract the optimal parameters was randomly performed, limiting the range values of three parameters and developing an accuracy decision method that is called the rate of concordance. The set of the optimal parameters was decided on highest the rate of concordance and a consistency. As a result, the optimal parameters in Bonghwa county were showed that the once flowing volume is $1.0m^3$, the stopping slope is $4.2^{\circ}$ and the gravity weight is 2 when the rate of concordance is -0.2. The validating result of the optimal parameters showed closely that the rate of concordance is average -0.2.

Comparison of morphometric traits between small yellow croaker (Larimichthys polyactis) and yellow croaker(L. crocea) (참조기(Larimichthys polyactis)와 부세(L. crocea) 간의 외부계측형질 비교)

  • Park, In-Seok;Oh, Ji Su
    • Korean Journal of Environmental Biology
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    • v.38 no.4
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    • pp.507-517
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    • 2020
  • Several methods including morphometric analysis were used to distinguish small yellow croaker (Larimichthys polyactis) from yellow croaker (Larimichthys crocea), which have very similar external shapes. Morphometric analysis showed four considerable differences (p<0.05) among the total 48 morphometric dimensions, but no differences were seen in the classical dimensions (p>0.05). Rather, significant differences were seen in two truss dimensions: Insertion of dorsal fin base - origin of pectoral fin base and origin of anal fin base - origin of pectoral fin base, and two head part dimension: most anterior extension of the head - above of eye and above of eye - posterior aspect of operculum(p<0.05). However, the yellow croaker had higher values than the small yellow croaker in the other three morphometric dimensions except for the head part dimension of above of eye - posterior aspect of operculum of the four morphometric dimensions (p<0.05). The X-ray photographs indicated that the small yellow croaker (45.1±2.34°) had 8.4% more curved vertebral column than the yellow croaker(38.4±1.82°). A diamond-shaped cranium was found when the skin was peeled off from both fish but the commonly held fact that only the small yellow croaker has a diamond-shaped cranium is not accurate. Our results confirmed that the two fish could be definitely distinguished by their external body shape.

Utilization of UAV Photogrammetry for Actual Condition Survey of Government Owned Lands (국·공유지 실태조사를 위한 UAV 사진측량의 활용성 검토)

  • LEE, Si-Wook;LEE, Jin-Duk
    • Journal of the Korean Association of Geographic Information Studies
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    • v.24 no.1
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    • pp.80-91
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    • 2021
  • The purpose of this study is to present the applicability to the effective survey into the actual condition of lands such as analysis of occupied location of government owned lands based on orthoimages created from aerial photographs taken by UAV. The boundary point coordinates and areas of the parcels were observed respectively by VRS-GNSS surveying and orthoimages for each land use of two categories of land, i.e. building site and farmland. As a result of comparing boundary point coordinates and areas extracted from UAV orthoimages with VRS-GNSS surveying data which were used as reference data, the RMS error of the coordinates for the boundary points was ±0.074m for both X and Y in the building site, and ±0.150m and ±0.127m for the X and Y respectively in the farmland. The positional error of the boundary point was 1.7~ 2 times higher in the farmland than in the building site where the boundary points were relatively clear. The RMS error of ±8.964㎡ of areas in the farmland was 4.7 times higher than that of ±1.898㎡ of areas in the building site. The area errors of all 22 parcels measured from the orthoimage were found to be within the allowed error range, indicating that it is feasible to apply the orthoimage generated by UAV to survey of government owned lands in terms of accuracy.

A Case Study on the Restoration to Designated State Based on the Scientific Analysis of Gold Threads of Gwanghwadang-Wonsam (광화당 원삼의 금사 분석과 원형복원 사례)

  • An, Boyeon;Lee, Ryangmi;Lee, Jangjon
    • Journal of Conservation Science
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    • v.37 no.2
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    • pp.144-153
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    • 2021
  • Gwanghwadang-Wonsam was designated as National Folklore Cultural Heritage No. 52 in 1979, it is in good condition. However, a problem is the attached a phoenix insignia badge that did not exist when it was designated recently. As it became known as the only purple Wonsam artifact with "phoenix insignia", raising the need for its conservation. In this regard, scientific analysis was required to correct misinformation about designated cultural assets and restore the original designated state by analyzing the history of the Gwanghwadang-Wonsam, other relics of the phoenix insignia and its making design patterns. An X-ray fluorescence analysis was used to confirm that the Phoenix insignia's metal threads were titanium-plated silver. Phoenix insignia using titanium-plated gold thread was not identified in Gwanghwadang-Wonsam photographs in 1986, and the TiN-type membrane plating method was used in various industries in the 1990s, which can be estimated to be attached in the early and mid-1990s. Especially, the scientific analysis results from the X-ray fluorescence analysis in this study provide key evidence for conservation processing. This study demonstrates the importance of investigating relics and similar artifacts in the conservation process of inherited relics and as a precedent for restoration that corrects misinformation about designated cultural properties.

Analysis on the Changes in Abandoned Paddy Wetlands as a Carbon Absorption Sources and Topographic Hydrological Environment (탄소흡수원으로서의 묵논습지 변화와 지형수문 환경 분석)

  • Miok, Park;Sungwon, Hong;Bonhak, Koo
    • Land and Housing Review
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    • v.14 no.1
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    • pp.83-97
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    • 2023
  • The study aims to provide an academic basis for the preservation and restoration of abandoned paddy wetland and the enhancement of its carbon accumulation function. First, the temporal change of the wetlands was analysed, and a typological classification system for wetlands was attempted with the goal of carbon reduction. The types of wetland were classified based on three variables: hydrological environment, vegetation, and carbon accumulation, with a special attention on the function of carbon accumulation. The types of abandoned paddy wetlands were classified into 12 categories based on hydrologic variables- either high or low levels of water inflow potential-, vegetation variables with either dominance of aquatic plants or terrestrial plants, and three carbon accumulation variables including organic matter production, soil organic carbon accumulation, and decomposition. It was found that the development period of abandoned paddy analyzed with aerial photographs provided by the National Geographic Information Institute happened between 2010 and 2015. In the case of the wetland in Daejeon 1 (DJMN01) farming stopped by 1990 and it appeared to be a similar structure to natural wetlands after 2010 . Over the past 40 years the abandoned paddy wetland changed to a high proportion of forests and agricultural lands. As time went by, such forests and agricultural lands tended to decrease rapidly and the lands were covered by artificial grass and other types of forests.

Corneal Ulcer Region Detection With Semantic Segmentation Using Deep Learning

  • Im, Jinhyuk;Kim, Daewon
    • Journal of the Korea Society of Computer and Information
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    • v.27 no.9
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    • pp.1-12
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    • 2022
  • Traditional methods of measuring corneal ulcers were difficult to present objective basis for diagnosis because of the subjective judgment of the medical staff through photographs taken with special equipment. In this paper, we propose a method to detect the ulcer area on a pixel basis in corneal ulcer images using a semantic segmentation model. In order to solve this problem, we performed the experiment to detect the ulcer area based on the DeepLab model which has the highest performance in semantic segmentation model. For the experiment, the training and test data were selected and the backbone network of DeepLab model which set as Xception and ResNet, respectively were evaluated and compared the performances. We used Dice similarity coefficient and IoU value as an indicator to evaluate the performances. Experimental results show that when 'crop & resized' images are added to the dataset, it segment the ulcer area with an average accuracy about 93% of Dice similarity coefficient on the DeepLab model with ResNet101 as the backbone network. This study shows that the semantic segmentation model used for object detection also has an ability to make significant results when classifying objects with irregular shapes such as corneal ulcers. Ultimately, we will perform the extension of datasets and experiment with adaptive learning methods through future studies so that they can be implemented in real medical diagnosis environment.

New record and prediction of the potential distribution of the invasive alien species Brassica tournefortii (Brassicaceae) in Korea (국내 침입외래식물 사막갓(Brassica tournefortii; Brassicaceae)의 보고 및 잠재 분포 예측)

  • KANG, Eun Su;KIM, Han Gyeol;NAM, Myoung Ja;CHOI, Mi Jung;SON, Dong Chan
    • Korean Journal of Plant Taxonomy
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    • v.52 no.3
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    • pp.184-195
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    • 2022
  • The invasive alien species Brassica tournefortii Gouan (Brassicaceae) is herein reported for the first time in Korea, from Gunsan-si, Gochang-gun, and Jeju-si. Brassica tournefortii can easily be distinguished from B. juncea and B. napus by its dense stiff hairs at the base of the stem and leaves, basally and distally branched stems, partially dehiscent fruits, and seeds that become mucilaginous in the presence of moisture. Although some taxonomists have classified this species as belonging to Coincya Rouy based on its fruit and seed characteristics, the existence of one vein on the fruit valves and our maximum likelihood analysis using internal transcribed spacer sequences placed it in Brassica. Distribution data, photographs, and a description of B. tournefortii are presented herein. Moreover, potential changes in the distribution of B. tournefortii were predicted under different climate scenarios, but our analysis showed that the probability of the spreading of this species is low. Nevertheless, continuous monitoring is necessary for an accurate assessment. The results of the present study can be used to conduct an invasion risk assessment and can assist with the effective management of this invasive alien species.

Analysis of the Effect of Learned Image Scale and Season on Accuracy in Vehicle Detection by Mask R-CNN (Mask R-CNN에 의한 자동차 탐지에서 학습 영상 화면 축척과 촬영계절이 정확도에 미치는 영향 분석)

  • Choi, Jooyoung;Won, Taeyeon;Eo, Yang Dam
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.40 no.1
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    • pp.15-22
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    • 2022
  • In order to improve the accuracy of the deep learning object detection technique, the effect of magnification rate conditions and seasonal factors on detection accuracy in aerial photographs and drone images was analyzed through experiments. Among the deep learning object detection techniques, Mask R-CNN, which shows fast learning speed and high accuracy, was used to detect the vehicle to be detected in pixel units. Through Seoul's aerial photo service, learning images were captured at different screen magnifications, and the accuracy was analyzed by learning each. According to the experimental results, the higher the magnification level, the higher the mAP average to 60%, 67%, and 75%. When the magnification rates of train and test data of the data set were alternately arranged, low magnification data was arranged as train data, and high magnification data was arranged as test data, showing a difference of more than 20% compared to the opposite case. And in the case of drone images with a seasonal difference with a time difference of 4 months, the results of learning the image data at the same period showed high accuracy with an average of 93%, confirming that seasonal differences also affect learning.

Change of Peroxiredoxin-5 Expression by Curcumin Treatment in Cerebral Ischemia (허혈성 대뇌손상시 curcumin 투여에 의한 peroxiredoxin-5 발현의 변화)

  • Gim, Sang-Ah;Koh, Phil-Ok
    • Journal of agriculture & life science
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    • v.50 no.3
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    • pp.129-139
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    • 2016
  • Curcumin plays a protective role in brain injury through its anti-oxidant and anti-inflammatory activities. Moreover, peroxiredoxin-5 exerts a protective effect against oxidative stress. The aim of this study was to investigate whether curcumin modulated the peroxiredoxin-5 expression in focal cerebral ischemic animal model. Middle cerebral artery occlusion(MCAO) was performed to induce cerebral ischemic injury in rats. Adult male rats were injected intraperitoneally with vehicle or curcumin(50mg/kg B.W.) 1 h after MCAO and cerebral cortex tissues were collected 24 h after MCAO. Photographs of hematoxylin and eosin staining showed that MCAO induced necrotic changes with scalloped shrunken form and apoptotic changes with nuclear chromatin condensations. However, curcumin treatment attenuated MCAO-induced histopathological changes. Moreover, this study clearly showed that peroxiredoxin-5 expression was decreased in MCAO operated animal with vehicle using a proteomics approach. However, this decrease in peroxiredoxin-5 expression was attenuated by curcumin treatment. Reverse-transcription PCR and Western blot analyses confirmed that curcumin treatment alleviated the MCAO injury-induced decrease in peroxiredoxin-5 expression(p<0.05). These results demonstrated that curcumin regulates peroxiredoxin-5 expression in MCAO animal model. In conclusion, our findings suggest that curcumin exerts a neuroprotective effect in cerebral ischemia by attenuating the MCAO-induced decrease in peroxiredoxin-5 expression.

Effect of Nano-sized Calcium-silicate-hydrate (C-S-H) Crystals on Cement Hydration (나노 크기 칼슘-실리케이트-하이드레이트(C-S-H) 결정이 시멘트 수화에 미치는 영향 분석)

  • Gyeong-Tae Kim;Su-Ji Woo;Sung-Won Yoo;Young-Cheol Choi
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.11 no.2
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    • pp.153-160
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    • 2023
  • In this study, nano-sized C-S-H crystals were synthesized using the liquid phase reaction method and their properties were investigated. The synthesized C-S-H crystals were added to the cement composite in suspension form to determine their effect on the hydration properties of the cement. The amount of chemical admixture was varied to obtain nano-sized C-S-H crystals with optimal agglomerated morphology, and SEM photographs were analyzed. A cleaning process was added to remove harmful substances other than the synthesiz ed C-S-H crystals. It was found that the concentration of harmful substances was reduced in the case of C-S-H crystals subjected to the cleaning process. The synthesized C-S-H suspensions were prepared with and without the cleaning process, and cement composites were prepared with the cement weight content as the main variable. The effect of C-S-H crystals on the initial hydration properties of the cement was confirmed by microhydration heat analysis. In addition, mortar specimens were prepared to measure the compressive strength over time. The test results showed that the nano-sized C-S-H crystals act as nucleation sites in the cement paste to promote the early hydration of the cement and increase the early compressive strength.