• Korean Journal of Optics and Photonics
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• v.31 no.1
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• pp.1-6
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• 2020

The chest wall, an organ directly affected by environmental particles through respiration, consists of ribs, a pleural layer and intercostal muscles. To diagnose early and treat disease in this body part, it is important to visualize the details of the chest wall, but the structure of the pleural layer cannot be seen by chest computed tomography or ultrasound. On the other hand, optical coherence tomography (OCT), with a high spatial resolution, is suited to observe pleural-layer response to talc, one of the fine materials. However, intensity-based OCT is weak in providing information to distinguish the detailed structure of the chest wall, and cannot distinguish the reaction of the pleural layer from the change in the muscle by the talc. Polarization-sensitive OCT (PS-OCT) takes advantage of the fact that specific tissues like muscle, which have optical birefringence, change the backscattered light's polarization state. Moreover, the birefringence of muscle associated with the arrangement of myofilaments indicates the muscle's condition, by measuring retardation change. The PS-OCT image is interpreted from three major perspectives for talc-exposure chest-wall imaging: a thickened pleural layer, a separation between pleural layer and muscle, and a phase-retardation measurement around lesions. In this paper, a rabbit chest wall after talc pleurodesis is investigated by PS-OCT. The PS-OCT images visualize the pleural layer and muscle, respectively, and this system shows different birefringence of normal and damaged lesions. Also, an analyisis based on phase-retardation slope supports results from the PS-OCT image and histology.

• Korean Journal of Remote Sensing
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• v.37 no.6_1
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• pp.1559-1572
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• 2021

The response of vegetation under the crop stress condition was evaluated using structural, biochemical, and physiological vegetation indices based on unmanned aerial vehicle (UAV) images and field-spectrometer data. A high concentration of herbicide was sprayed at the different growth stages of garlic to process crop stress, the above ground dry matter of garlic at experimental area (EA) decreased about 46.2~84.5% compared to that at control area. The structural vegetation indices clearly responded to these crop damages. Spectral reflectance at near-infrared wavelength consistently decreased at EA. Most biochemical vegetation indices reflected the crop stress conditions, but the meaning of physiological vegetation indices is not clear due to the effect of vinyl mulching. The difference of the decreasing ratio of vegetation indices after the herbicide spray was 2.3% averagely in the case of structural vegetation indices and 1.3~4.1% in the case of normalization-based vegetation indices. These results meant that appropriate vegetation indices should be utilized depending on the types of crop stress and the cultivation environment and the normalization-based vegetation indices measured from the different spatial scale has the minimized difference.

• Korean Journal of Remote Sensing
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• v.37 no.5_3
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• pp.1475-1490
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• 2021

Detecting oil spill area using statistical characteristics of SAR images has limitations in that classification algorithm is complicated and is greatly affected by outliers. To overcome these limitations, studies using neural networks to classify oil spills are recently investigated. However, the studies to evaluate whether the performance of model shows a consistent detection performance for various oil spill cases were insufficient. Therefore, in this study, two CNNs (Convolutional Neural Networks) with basic structures(Simple CNN and U-net) were used to discover whether there is a difference in detection performance according to the structure of CNN and distribution characteristics of oil spill. As a result, through the method proposed in this study, the Simple CNN with contracting path only detected oil spill with an F1 score of 86.24% and U-net, which has both contracting and expansive path showed an F1 score of 91.44%. Both models successfully detected oil spills, but detection performance of the U-net was higher than Simple CNN. Additionally, in order to compare the accuracy of models according to various oil spill cases, the cases were classified into four different categories according to the spatial distribution characteristics of the oil spill (presence of land near the oil spill area) and the clarity of border between oil and seawater. The Simple CNN had F1 score values of 85.71%, 87.43%, 86.50%, and 85.86% for each category, showing the maximum difference of 1.71%. In the case of U-net, the values for each category were 89.77%, 92.27%, 92.59%, and 92.66%, with the maximum difference of 2.90%. Such results indicate that neither model showed significant differences in detection performance by the characteristics of oil spill distribution. However, the difference in detection tendency was caused by the difference in the model structure and the oil spill distribution characteristics. In all four oil spill categories, the Simple CNN showed a tendency to overestimate the oil spill area and the U-net showed a tendency to underestimate it. These tendencies were emphasized when the border between oil and seawater was unclear.

• Korean Journal of Remote Sensing
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• v.37 no.6_3
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• pp.1985-1999
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• 2021

The purpose of this study is to apply urban heat island reduction techniques(green roof, cool roof, and cool pavements using heat insulation paint or blocks) recommended by the Environmental Protection Agency (EPA) to our study area and determine their actual effects through a comparative analysis between land cover objects. To this end, the area of Mugye-ri, Jangyu-myeon, Gimhae, Gyeongsangnam-do was selected as a study area, and measurements were taken using a drone DJI Matrice 300 RTK, which was equipped with a thermal infrared sensor FLIR Vue Pro R and a visible spectrum sensor H20T 1/2.3" CMOS, 12 MP. A total of nine heat maps, land cover objects (711) as a control group, and heat island reduction technique-applied land covering objects (180) were extracted every 1 hour and 30 minutes from 7:15 am to 7:15 pm on July 27. After calculating the effect values for each of the 180 objects extracted, the effects of each technique were integrated. Through the analysis based on daytime hours, the effect of reducing heat islands was found to be 4.71℃ for cool roof; 3.40℃ for green roof; and 0.43℃ and -0.85℃ for cool pavements using heat insulation paint and blocks, respectively. Comparing the effect by time period, it was found that the heat island reduction effect of the techniques was highest at 13:00, which is near the culmination hour, on the imaging date. Between 13:00 and 14:30, the efficiency of temperature reduction changed, with -8.19℃ for cool roof, -5.56℃ for green roof, and -1.78℃ and -1.57℃ for cool pavements using heat insulation paint and blocks, respectively. This study was a case study that verified the effects of urban heat island reduction techniques through the use of high-resolution images taken with drones. In the future, it is considered that it will be possible to present case studies that directly utilize micro-satellites with high-precision spatial resolution.

• Korean Journal of Environment and Ecology
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• v.32 no.6
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• pp.686-697
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• 2018

Due to the advance in remote sensing technology, it has become easier to more frequently obtain high resolution imagery to detect delicate changes in an extensive area, particularly including forest which is not readily sub-classified. Time-series analysis on high resolution images requires to collect extensive amount of ground truth data. In this study, the potential of land coverage mapas ground truth data was tested in classifying high-resolution imagery. The study site was Wonju-si at Gangwon-do, South Korea, having a mix of urban and natural areas. KOMPSAT-3A imagery taken on March 2015 and land coverage map published in 2017 were used as source data. Two pixel-based classification algorithms, Support Vector Machine (SVM) and Random Forest (RF), were selected for the analysis. Forest only classification was compared with that of the whole study area except wetland. Confusion matrixes from the classification presented that overall accuracies for both the targets were higher in RF algorithm than in SVM. While the overall accuracy in the forest only analysis by RF algorithm was higher by 18.3% than SVM, in the case of the whole region analysis, the difference was relatively smaller by 5.5%. For the SVM algorithm, adding the Majority analysis process indicated a marginal improvement of about 1% than the normal SVM analysis. It was found that the RF algorithm was more effective to identify the broad-leaved forest within the forest, but for the other classes the SVM algorithm was more effective. As the two pixel-based classification algorithms were tested here, it is expected that future classification will improve the overall accuracy and the reliability by introducing a time-series analysis and an object-based algorithm. It is considered that this approach will contribute to improving a large-scale land planning by providing an effective land classification method on higher spatial and temporal scales.

• Korean Journal of Heritage: History & Science
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• v.51 no.2
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• pp.22-37
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• 2018

Unmanned aerial vehicles (UAV) have attracted considerable attention both at home and abroad. The UAV is equipped with a camera that shoots images, which is advantageous for access to areas where archaeological investigations are not possible. Moreover, it is possible to acquire three-dimensional spatial image information by modeling the terrain through aerial photographing, and it is possible to specify the interpretation of the terrain of the survey area. In addition, if we understand the change of the terrain through comparison with past aerial photographs, it will be very helpful to grasp the existence of the ruins. The terrain modeling for searching these remains can be divided into two parts. First, we acquire the aerial photographs of the current terrain using the drone. Then, using image registration and post-processing, we complete the image-joining and terrain-modeling using past aerial photographs. The completed modeled terrain can be used to derive several analytical results. In the present terrain modeling, terrain analysis such as DSM, DTM, and altitude analysis can be performed to roughly grasp the characteristics of the change in the form, quality, and micro-topography. Past terrain modeling of aerial photographs allows us to understand the shape of landforms and micro-topography in wetlands. When verified with actual findings and overlapping data on the modelling of each terrain, it is believed that changes in hill shapes and buried Microform can be identified as helpful when used in low-flying applications. Thus, modeling data using aerial photographs is useful for identifying the reasons for the inability to carry out archaeological surveys, the existence of terrain and ruins in a wide area, and to discuss the preservation process of the ruins. Furthermore, it is possible to provide various themes, such as cadastral maps and land use maps, through comparison of past and present topographical data. However, it is certain that it will function as a new investigation methodology for the exploration of ruins in order to discover archaeological cultural properties.

• Journal of Korea Entertainment Industry Association
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• v.15 no.8
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• pp.145-159
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• 2021

is a contemporary experimental film that forms ambiguity in the narrative and the psychological motivation of the characters, destroys linear temporality, and reminds of manipulation possibilities in digital images through varied techniques, and it carries implication by the fact that the transformation process of human subjects and self-awareness are connected to social trauma and makes way to infer by comparing it to the historical contexts of other nations or societies. centers on the space outside the screen, absent space, and the intrinsic meaning within the space and the frame and shares the information in the visible space and the space outside the screen and arouses an active perceptual process so that the audience can deduce the information that is not presented. The film visualized the historical meaning without describing the background of the times in detail and aimed to express the conflicts and worries between the god, a transcendental existence, with humans, which are marginal beings, within the conflicting structure among humans. Moreover, attempted to resolve the sadness of loss and absence through the spatial aesthetics and the film presented the progression of the situation through the contrast of the characters and also the comparison between light and darkness. This study intends to make an attempt of interpreting the realm involving personal (characters) stories and the social and historical backgrounds together with the religious sphere and discuss the visualization of the semantic context. In addition, this study analyzed the sequence of the scenes in , which reconstructs identity and historical cases and religious values to observe the meaning and characteristics and closely analyze the general meaning pursued by the film. discussed the issues of trauma that individuals, regions, and nations confront as a representation and interpretation of the trauma connoted in the film, and consideration can be provided about the implication concerning the situation and context in South Korea. Furthermore, the film placidly discusses the growth and agony in humans and the society without expressing it excessively, so it will be a valuable research result to inspire the trend of creating films that incorporate new imaging technology and original visualization techniques.

• MISULJARYO - National Museum of Korea Art Journal
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• v.96
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• pp.239-260
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• 2019

This paper examines the circulation and dissemination of painting during and after the nineteenth century through a case study on the One Hundred Fans paintings produced as decorative folding screens at the time. One Hundred Fans paintings refer to depictions of layers of fans in various shapes on which pictures of diverse themes are drawn. Fans and paintings on fans were depicted on paintings before the nineteenth century. However, it was in the nineteenth century that they began to be applied as subject matter for decorative paintings. Reflecting the trend of enjoying extravagant hobbies, fans and paintings on fans were mainly produced as folding screens. The folding screen of One Hundred Fans from the collection of the Museum am Rothenbaum Kulturen und Künste der Welt (hereafter Rothenbaum Museum) in Germany was first introduced to Korean in the exhibition The City in Art, Art in the City held at the National Museum of Korea in 2016. Each panel in this six-panel folding screen features more than five different fans painted with diverse topics. This folding screen is of particular significance since the National Museum of Korea holds the original drawings. In the nineteenth century, calligraphy and painting that had formerly been enjoyed by Joseon royal family members and the nobility in private spaces began to spread among common people and was distributed through markets. In accordance with the trend of adorning households, colorful decorative paintings were preferred, leading to the popularization of the production of One Hundred Fans folding screens with pictures in different shapes and themes. A majority of the Korean collection in the Rothenbaum Museum belonged to Heinrich Constantin Eduard Meyer(1841~1926), a German businessman who served as the Joseon consul general in Germany. From the late 1890s until 1905, Meyer traveled back and forth between Joseon and Germany and collected a wide range of Korean artifacts. After returning to Germany, he sequentially donated his collections, including One Hundred Fans, to the Rothenbaum Museum. Folding screens like One Hundred Fans with their fresh and decorative beauty may have attracted the attention of foreigners living in Joseon. The One Hundred Fans at the Rothenbaum Museum is an intriguing work in that during its treatment, a piece of paper with the inscription of the place name "Donghyeon" was found pasted upside down on the back of the second panel. Donghyeon was situated in between Euljiro 1-ga and Euljiro 2-ga in present-day Seoul. During the Joseon Dynasty, a domestic handicraft industry boomed in the area based on licensed shops and government offices, including the Dohwaseo (Royal Bureau of Painting), Hyeminseo (Royal Bureau of Public Dispensary), and Jangagwon (Royal Bureau of Music). In fact, in the early 1900s, shops selling calligraphy and painting existed in Donghyeon. Thus, it is very likely that the shops where Meyer purchased his collection of calligraphy and painting were located in Donghyeon. The six-panel folding screen One Hundred Fans in the collection of the Rothenbaum Museum is thought to have acquired its present form during a process of restoring Korean artifacts works in the 1980s. The original drawings of One Hundred Fans currently housed in the National Museum of Korea was acquired by the National Folk Museum of Korea between 1945 and 1950. Among the seven drawings of the painting, six indicate the order of their panels in the margins, which relates that the painting was originally an eight-panel folding screen. Each drawing shows more than five different fans. The details of these fans, including small decorations and patterns on the ribs, are realistically depicted. The names of the colors to be applied, including 'red ocher', 'red', 'ink', and 'blue', are written on most of the fans, while some are left empty or 'oil' is indicated on them. Ten fans have sketches of flowers, plants, and insects or historical figures. A comparison between these drawings and the folding screen of One Hundred Fans at the Rothenbaum Museum has revealed that their size and proportion are identical. This shows that the Rothenbaum Museum painting follows the directions set forth in the original drawings. The fans on the folding screen of One Hundred Fans at the Rothenbaum Museum are painted with images on diverse themes, including landscapes, narrative figures, birds and flowers, birds and animals, plants and insects, and fish and crabs. In particular, flowers and butterflies and fish and crabs were popular themes favored by nineteenth century Joseon painters. It is noteworthy that the folding screen One Hundred Fans at the Rothenbaum Museum includes several scenes recalling the typical painting style of Kim Hong-do, unlike other folding screens of One Hundred Fans or Various Paintings and Calligraphy. As a case in point, the theme of "Elegant Gathering in the Western Garden" is depicted in the Rothenbaum folding screen even though it is not commonly included in folding screens of One Hundred Fans or One Hundred Paintings due to spatial limitations. The scene of "Elegant Gathering in the Western Garden" in the Rothenbaum folding screen bears a resemblance to Kim Hong-do's folding screen of Elegant Gathering in the Western Garden at the National Museum of Korea in terms of its composition and style. Moreover, a few scenes on the Rothenbaum folding screen are similar to examples in the Painting Album of Byeongjin Year produced by Kim Hong-do in 1796. The painter who drew the fan paintings on the Rothenbaum folding screen is presumed to have been influenced by Kim Hong-do since the fan paintings of a landscape similar to Sainsam Rock, an Elegant Gathering in the Western Garden, and a Pair of Pheasants are all reminiscent of Kim's style. These paintings in the style of Kim Hong-do are reproduced on the fans left empty in the original drawings. The figure who produced both the original drawings and fan paintings appears to have been a professional painter influenced by Kim Hong-do. He might have appreciated Kim's Painting Album of Byeongjin Year or created duplicates of Painting Album of Byeongjin Year for circulation in the art market. We have so far identified about ten folding screens remaining with the One Hundred Fans. The composition of these folding screens are similar each other except for a slight difference in the number and proportion of the fans or reversed left and right sides of the fans. Such uniform composition can be also found in the paintings of scholar's accoutrements in the nineteenth century. This suggests that the increasing demand for calligraphy and painting in the nineteenth century led to the application of manuals for the mass production of decorative paintings. As the demand for colorful decorative folding screens with intricate designs increased from the nineteenth century, original drawings began to be used as models for producing various paintings. These were fully utilized when making large-scale folding screens with images such as Guo Ziyi's Enjoyment-of-Life Banquet, Banquet of the Queen Mother of the West, One Hundred Children, and the Sun, Cranes and Heavenly Peaches, all of which entailed complicated patterns. In fact, several designs repeatedly emerge in the extant folding screens, suggesting the use of original drawings as models. A tendency toward using original drawings as models for producing folding screens in large quantities in accordance with market demand is reflected in the production of the folding screens of One Hundred Fans filled with fans in different shapes and fan paintings on diverse themes. In the case of the folding screens of One Hundred Paintings, bordering frames are drawn first and then various paintings are executed inside the frames. In folding screens of One Hundred Fans, however, fans in diverse forms were drawn first. Accordingly, it must have been difficult to produce them in bulk. Existing examples are relatively fewer than other folding screens. As discussed above, the folding screen of One Hundred Fans at the Rothenbaum Museum and its original drawings at the National Museum of Korea aptly demonstrate the late Joseon painting trend of embracing and employing new painting styles. Further in-depth research into the Rothenbaum painting is required in that it is a rare example exhibiting the influence of Kim Hong-do compared to other paintings on the theme of One Hundred Fans whose composition and painting style are more similar to those found in the work of Bak Gi-jun.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.1
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• pp.30-41
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• 2007

Purpose: Bone metastasis in breast cancer patients are usually assessed by conventional Tc-99m methylene diphosphonate whole-body bone scan, which has a high sensitivity but a poor specificity. However, positron emission tomography with $^{18}F-2-deoxyglucose$ (FDG-PET) can offer superior spatial resolution and improved specificity. FDG-PET/CT can offer more information to assess bone metastasis than PET alone, by giving a anatomical information of non-enhanced CT image. We attempted to evaluate the usefulness of FDG-PET/CT for detecting bone metastasis in breast cancer and to compare FDG-PET/CT results with bone scan findings. Materials and Methods: The study group comprised 157 women patients (range: $28{\sim}78$ years old, $mean{\pm}SD=49.5{\pm}8.5$) with biopsy-proven breast cancer who underwent bone scan and FDG-PET/CT within 1 week interval. The final diagnosis of bone metastasis was established by histopathological findings, radiological correlation, or clinical follow-up. Bone scan was acquired over 4 hours after administration of 740 MBq Tc-99m MDP. Bone scan image was interpreted as normal, low, intermediate or high probability for osseous metastasis. FDG PET/CT was performed after 6 hours fasting. 370 MBq F-18 FDG was administered intravenously 1 hour before imaging. PET data was obtained by 3D mode and CT data, used as transmission correction database, was acquired during shallow respiration. PET images were evaluated by visual interpretation, and quantification of FDG accumulation in bone lesion was performed by maximal SUV(SUVmax) and relative SUV(SUVrel). Results: Six patients(4.4%) showed metastatic bone lesions. Four(66.6%) of 6 patients with osseous metastasis was detected by bone scan and all 6 patients(100%) were detected by PET/CT. A total of 135 bone lesions found on either FDG-PET or bone scan were consist of 108 osseous metastatic lesion and 27 benign bone lesions. Osseous metastatic lesion had higher SUVmax and SUVrel compared to benign bone lesion($4.79{\pm}3.32$ vs $1.45{\pm}0.44$, p=0.000, $3.08{\pm}2.85$ vs $0.30{\pm}0.43$, p=0.000). Among 108 osseous metastatic lesions, 76 lesions showed as abnormal uptake on bone scan, and 76 lesions also showed as increased FDG uptake on PET/CT scan. There was good agreement between FDG uptake and abnormal bone scan finding (Kendall tau-b : 0.689, p=0.000). Lesion showed increased bone tracer uptake had higher SUVmax and SUVrel compared to lesion showed no abnormal bone scan finding ($6.03{\pm}3.12$ vs $1.09{\pm}1.49$, p=0.000, $4.76{\pm}3.31$ vs $1.29{\pm}0.92$, p=0.000). The order of frequency of osseous metastatic site was vertebra, pelvis, rib, skull, sternum, scapula, femur, clavicle, and humerus. Metastatic lesion on skull had highest SUVmax and metastatic lesion on rib had highest SUVrel. Osteosclerotic metastatic lesion had lowest SUVmax and SUVrel. Conclusion: These results suggest that FDG-PET/CT is more sensitive to detect breast cancer patients with osseous metastasis. CT scan must be reviewed cautiously skeleton with bone window, because osteosclerotic metastatic lesion did not showed abnormal FDG accumulation frequently.