• 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.

• Journal of Sericultural and Entomological Science
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• v.50 no.2
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• pp.63-70
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• 2012

This study was conducted to investigated the distribution, ecological character and life cycle of Black Soldier Fly(BSF), Hermetia illucens, to determine effects of BSF on composing ability to the livestock feces. The distribution of BSF was defined in all parts of the country in Korea. Its main habitat was found to be areas near cattle sheds, feces sheds, living waste dump grounds, and food waste dump grounds. Excellent species of the bio-conversion using the livestock feces were selected out of two kinds of solider flies(Hermetia illucens and Ptecticus tenebrifer). And effects of BSF on composing ability to the livestock feces were pig feces 0.5 g, cattle feces 0.43 g and chicken feces 0.3 g per a larvae of BSF. In the examination of the ability of BSF to decompose food waste, volume of the livestock feces decreased by weight pig feces 77, cattle feces 83.62 and chicken feces 80%. Observed characteristics of BSF larvae and pupae stage were by developmental stage may be summarized as follows: size and length of larvae and pupae of BSF were higher than in pig feces and mixed sawdust treatments. In order to develop artificial indoor rearing techniques, The pupation and emergence rate were not visible the difference but important factor of the mating and egg-laying was a sun light. And it was visible the difference in mating ratio. Mating rate of H. illucens by seasonal change was the highest from May to July. Mating mostly occurred between 10 : 00 and 12 : 00 during which light intensity is high. As the egg-laying medium for artificial egg collection, calf feed and food waste were most effective. The ratio of egg-laying medium is waste food : sawdust(1 : 1) in volume. For egg-laying materials, flower foam and wood with holes were used; holes sized 3 ~ 5 mm in diameter, 7 ~ 10 mm in depth were most preferred for egg-laying.

• Korean Journal of Remote Sensing
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• v.37 no.5_3
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• pp.1373-1387
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• 2021

Forest fire poses a significant threat to the environment and society, affecting carbon cycle and surface energy balance, and resulting in socioeconomic losses. Widely used multi-spectral satellite image-based approaches for burned area detection have a problem in that they do not work under cloudy conditions. Therefore, in this study, Sentinel-1 Synthetic Aperture Radar (SAR) data from Europe Space Agency, which can be collected in all weather conditions, were used to identify forest fire damaged area based on a series of processes including Principal Component Analysis (PCA) and K-means clustering. Four forest fire cases, which occurred in Gangneung·Donghae and Goseong·Sokcho in Gangwon-do of South Korea and two areas in North Korea on April 4, 2019, were examined. The estimated burned areas were evaluated using fire reference data provided by the National Institute of Forest Science (NIFOS) for two forest fire cases in South Korea, and differenced normalized burn ratio (dNBR) for all four cases. The average accuracy using the NIFOS reference data was 86% for the Gangneung·Donghae and Goseong·Sokcho fires. Evaluation using dNBR showed an average accuracy of 84% for all four forest fire cases. It was also confirmed that the stronger the burned intensity, the higher detection the accuracy, and vice versa. Given the advantage of SAR remote sensing, the proposed statistical processing and K-means clustering-based approach can be used to quickly identify forest fire damaged area across the Korean Peninsula, where a cloud cover rate is high and small-scale forest fires frequently occur.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.401-409
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• 2021

This study aimed to estimate the photosynthetic capacity of tomato plants grown in a semi-closed greenhouse using temperature response models of plant photosynthesis by calculating the ribulose 1,5-bisphosphate carboxylase/oxygenase maximum carboxylation rate (V_cmax), maximum electron transport rate (J_max), thermal breakdown (high-temperature inhibition), and leaf respiration to predict the optimal conditions of the CO₂-controlled greenhouse, for maximizing the photosynthetic rate. Gas exchange measurements for the A-C_i curve response to CO₂ level with different light intensities {PAR (Photosynthetically Active Radiation) 200µmol·m^-2·s^-1 to 1500µmol·m^-2·s^-1} and leaf temperatures (20℃ to 35℃) were conducted with a portable infrared gas analyzer system. Arrhenius function, net CO₂ assimilation (A_n), thermal breakdown, and daylight leaf respiration (R_d) were also calculated using the modeling equation. Estimated J_max, A_n, Arrhenius function value, and thermal breakdown decreased in response to increased leaf temperature (> 30℃), and the optimum leaf temperature for the estimated J_max was 30℃. The CO₂ saturation point of the fifth leaf from the apical region was reached at 600ppm for 200 and 400µmol·m^-2·s^-1 of PAR, at 800ppm for 600 and 800µmol·m^-2·s^-1 of PAR, at 1000ppm for 1000µmol of PAR, and at 1500ppm for 1200 and 1500µmol·m^-2·s^-1 of PAR levels. The results suggest that the optimal conditions of CO₂ concentration can be determined, using the photosynthetic model equation, to improve the photosynthetic rates of fruit vegetables grown in greenhouses.

• Science of Emotion and Sensibility
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• v.21 no.4
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• pp.55-62
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• 2018

The two main requirements of wearable optical fiber fabrics are that they must presuppose a high degree of flexibility and they must maintain the luminance effect in both flat and bent conformations. Therefore, woven optical fiber fabrics that satisfy the above conditions were developed by both weaving and by using computer embroidery. First, we measured the brightness of the wearable optical fiber fabric in the flat state at a total of 10 measurement points at intervals of 1 cm. Second, the wearable optical fiber fabric was placed horizontally on the forearm, where three-dimensional bending occurs, and the luminance values were recorded at the same 10 measurement points. For the woven fabric in the flat state, the maximum, minimum, average, and standard deviation luminance values were $5.23cd/m^2$, $2.74cd/m^2$, $3.56cd/m^2$, and $1.11cd/m^2$, respectively. The corresponding luminance values from the bent forearm were $7.92cd/m^2$ (maximum), $2.37cd/m^2$ (minimum), $4.42cd/m^2$ (average), and $2.16cd/m^2$ (standard deviation). In the case of the computer-embroidered fabric, the maximum, minimum, average, and standard deviation luminance values in the flat state were $7.56cd/m^2$, $3.84cd/m^2$, $5.13cd/m^2$, and $1.04cd/m^2$, respectively, and in the bent forearm state were $9.6cd/m^2$, $3.63cd/m^2$, $6.13cd/m^2$, and $2.26cd/m^2$, respectively. Therefore, the computer-embroidered fabric exhibited a higher luminous effect than the woven fabric because the detailed structure reduced light-loss due to the backside fabric. In both types of wearable optical fiber fabric the luminance at the forearm was 124% and 119%, respectively, and the light emitting effect of the optical fiber fabric was maintained even when bent by the human body. This is consistent with the principle of Huygens, which defines the wave theory of light, and also the Huygens-Fresnel-Kirchhoff principle, which states that the intensity of light increases according to the magnitude of the angle of propagation of the light wavefront (${\theta}$).

• Journal of Korean Society of Forest Science
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• v.110 no.2
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• pp.165-178
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• 2021

Owing to the lack of consistent research on endangered plant species in Korea, there are insufficient data to preservespecies and expand habitats. This study analyzed the preferred habitat and threats to the survival of Aconitum austrokoreense, found on Baekwun Mountain in Gurye-gun, Gwangyang-si, Jeollanam-do Province, and classified as a level two endangered wild plant by the Ministry of Environment, by investigating major environmental factors such as climate, location, soil, and stand structure. By examining five selected sites inhabited by Aconitum austrokoreense on BaekwunMountain, this study found that the habitat had an altitude of 420 to 675 m above sea level and showed a northeast tendency, spreading over a range of inclination angles between 15° and 37°. The average number of plants across the five sites was 156. Site 4 (550 m) had the highest density of 372 plants, with an average height of 0.6 m. The average soil moisture and relative light intensity were 20.48% and 7.34%, respectively. Layer soil was presumed to be sandy loam, characterized by high sand content and good drainage. The habitat had average soil pH of 5.2, average organic matter of 16.46%, average nitrogen of 0.86%, average available phosphate of 11.86 mg/kg, average electrical conductivity of 0.44 dS/m, and average cation exchange capacity of 37.04 cmolc/kg. The total carbon in soil averaged 10.68%. From the analysis of the vegetation structure of sites inhabited by Aconitum austrokoreense, the dominant populations were Pinus koraiensis and Lindera erythrocarpa in Site 1, Magnolia obovata and Carpinus laxiflora in Site 2, Zelkova serrate and Quercus variabilis in Site 3, Staphylea bumalda and Lindera erythrocarpa in Site 4, and Morus bombycis,Styrax japonicus, and Carpinus laxiflora in Site 5. With most habitats located near trails and sap collection sites of Acer pictum, the species were exposed to artificial damage and interference threats.

• Journal of Environmental Impact Assessment
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• v.30 no.5
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• pp.271-296
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• 2021

Since the thermal stratification in a reservoir inhibits the vertical mixing of the upper and lower layers and causes the formation of a hypoxia layer and the enhancement of nutrients release from the sediment, changes in the stratification structure of the reservoir according to future climate change are very important in terms of water quality and aquatic ecology management. This study was aimed to develop a data-driven inflow water temperature prediction model for Daecheong Reservoir (DR), and to predict future inflow water temperature and the stratification structure of DR considering future climate scenarios of Representative Concentration Pathways (RCP). The random forest (RF)regression model (NSE 0.97, RMSE 1.86℃, MAPE 9.45%) developed to predict the inflow temperature of DR adequately reproduced the statistics and variability of the observed water temperature. Future meteorological data for each RCP scenario predicted by the regional climate model (HadGEM3-RA) was input into RF model to predict the inflow water temperature, and a three-dimensional hydrodynamic model (AEM3D) was used to predict the change in the future (2018~2037, 2038~2057, 2058~2077, 2078~2097) stratification structure of DR due to climate change. As a result, the rates of increase in air temperature and inflow water temperature was 0.14~0.48℃/10year and 0.21~0.41℃/10year,respectively. As a result of seasonal analysis, in all scenarios except spring and winter in the RCP 2.6, the increase in inflow water temperature was statistically significant, and the increase rate was higher as the carbon reduction effort was weaker. The increase rate of the surface water temperature of the reservoir was in the range of 0.04~0.38℃/10year, and the stratification period was gradually increased in all scenarios. In particular, when the RCP 8.5 scenario is applied, the number of stratification days is expected to increase by about 24 days. These results were consistent with the results of previous studies that climate change strengthens the stratification intensity of lakes and reservoirs and prolonged the stratification period, and suggested that prolonged water temperature stratification could cause changes in the aquatic ecosystem, such as spatial expansion of the low-oxygen layer, an increase in sediment nutrient release, and changed in the dominant species of algae in the water body.

• Journal of Korea Water Resources Association
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• v.54 no.6
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• pp.419-431
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• 2021

In Seoul, it has been confirmed that the duration of rainfall is shortened and the frequency and intensity of heavy rains are increasing with a changing climate. In addition, due to high population density and urbanization in most areas, floods frequently occur in flood-prone areas for the increase in impermeable areas. Furthermore, the Seoul City is pursuing various projects such as structural and non-structural measures to resolve flood-prone areas. A disaster prevention performance target was set in consideration of the climate change impact of future precipitation, and this study conducted to reduce the overall flood damage in Seoul for the long-term. In this study, 29 GCMs with RCP4.5 and RCP8.5 scenarios were used for spatial and temporal disaggregation, and we also considered for 3 research periods, which is short-term (2006-2040, P1), mid-term (2041-2070, P2), and long-term (2071-2100, P3), respectively. For spatial downscaling, daily data of GCM was processed through Quantile Mapping based on the rainfall of the Seoul station managed by the Korea Meteorological Administration and for temporal downscaling, daily data were downscaled to hourly data through k-nearest neighbor resampling and nonparametric temporal detailing techniques using genetic algorithms. Through temporal downscaling, 100 detailed scenarios were calculated for each GCM scenario, and the IDF curve was calculated based on a total of 2,900 detailed scenarios, and by averaging this, the change in the future extreme rainfall was calculated. As a result, it was confirmed that the probability of rainfall for a duration of 100 years and a duration of 1 hour increased by 8 to 16% in the RCP4.5 scenario, and increased by 7 to 26% in the RCP8.5 scenario. Based on the results of this study, the amount of rainfall designed to prepare for future climate change in Seoul was estimated and if can be used to establish purpose-wise water related disaster prevention policies.

• Journal of Bio-Environment Control
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• v.31 no.1
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• pp.28-34
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• 2022

This study was conducted to determine the changes in ginsenosides content according to additional UV-A, and UV-B LED irradiation before harvesting the ginseng sprouts. One-year-old ginseng seedlings (n=100) were transplanted in a tray containing a ginseng medium. The ginseng sprouts were grown for 37 days at a temperature of 20℃ (24h), a humidity of 70%, and an average light intensity of 80 µmol·m^-2·s^-1 (photoperiod; 24h) in a container-type plant factory. Ginseng sprouts were then transferred to a custom chamber equipped with UV-A (370 nm; 12.90 W·m^-2) and UV-B (300 nm; 0.31 W·m^-2) LEDs and treated for 3 days. Growth parameters and ginsenoside contents in shoot and root were conducted by harvesting on days 0 (control), 1, 2, and 3 of UV treatments, respectively. The growth parameters showed non-significant differences between the control and the UV treatments (wavelengths or the number of days). Ginsenoside contents of the shoot was highly improved by 186% in UV-A treatment compared to the control in 3 days of the treatment time. The ginsenoside contents of the roots was more improved in UV-A 1-day treatment and UV-B 3-day treatment, compared to the control by 171% and 160%, respectively. As a result of this experiment, it is thought that UV LED irradiation before harvesting can produce sprout ginseng with high ginsenoside contents in a plant factory.

• Land and Housing Review
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• v.14 no.4
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• pp.17-37
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• 2023

The rental housing market in South Korea, specifically monthly rent with deposit, has been expanding over the last three decades (8.2% in 1990 to 21.0% in 2020), partly replacing the traditional Jeonse market. The distribution of rent has changed due to public rental subsidies and the emergence of luxury rental housing, while the distribution of rental household income has been polarized because of the emergence of rich renters. This study attempts to measure the structural changes in the rental market by developing a new indicator of income-rent mismatch. Using the seven series of the Korea Housing Survey, this study analyzed the changes in rent (reflecting the conversion rate) and income levels of rental households in 2006 (base year) and 10-15 years later (the analysis year) at the national level and at the spatial unit of 16 metropolitan cities and provinces (excluding Sejong), respectively, by dividing them into quartile data. The result reveals that rental housing was undersupplied in middle- and high-income rental housing due to the decline in the highest quartile (25%→18%) and the third quartile groups (25%→20%), while the supply of public rental housing expanded for the second quartile (25%→28%) and the lowest quartile (25%→35) groups. On the demand side, the highest income quartile shrank (25%→21%), while the lowest income quartile grew (25%→31%). Comparing the 16 metropolitan cities and provinces, there were significant regional differences in the direction and intensity of changes in rent and renter household income. In particular, the rental market in Seoul was characterized by supply polarization, which led to an imbalance in the income distribution of rental households. The structural changes in the apartment rental market were different from those in the non-apartment rental market. The findings of this study can be used as a basis for future regional rental housing markets. The findings can support securing affordable rental housing stock for each income quartile group on monthly rent and developing housing stability measures for a balance between income and rent distribution in each region.