• Journal of Bio-Environment Control
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• v.33 no.1
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• pp.63-70
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• 2024

This study explored computer vision methods using the OpenCV open-source library to characterize the phenotypes of various horticultural crops. In the case of tomatoes, image color was examined to assess ripeness, while support vector machine (SVM) and histogram of oriented gradients (HOG) methods effectively identified ripe tomatoes. For sweet pepper, we visualized the color distribution and used the Gaussian mixture model for clustering to analyze its post-harvest color characteristics. For the quality assessment of netted melons, the LAB (lightness, a, b) color space, binary images, and depth mapping were used to measure the net patterns of the melon. In addition, a combination of depth and color data proved successful in identifying flowers of different sizes and distances in cucumber greenhouses. This study highlights the effectiveness of these computer vision strategies in monitoring the growth and development, ripening, and quality assessment of fruits and vegetables. For broader applications in agriculture, future researchers and developers should enhance these techniques with plant physiological indicators to promote their adoption in both research and practical agricultural settings.

• Clean Technology
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• v.30 no.3
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• pp.175-187
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• 2024

Seaweeds are widely distributed along national coastlines around the world, and the biomass derived from them is an important marine biological organism. Seaweed is a crucial component of a healthy marine ecosystem. However, changes in marine environments have led to the occurrence of urchin barrens, and the damage caused by this phenomenon is steadily increasing. As a result, investigations into the distribution and spread of urchin barrens in the coastal areas of South Korea are being conducted regularly so efficient detection technologies are essential. One of the technologies that can swiftly and accurately analyze extensive areas is detection technology based on hyperspectral image information systems. This study aims to present the latest hyperspectral imaging technology for investigating the current status of urchin barrens and the methods for classifying this technology, including principles, preprocessing techniques, and correction methods. This study also proposes a classification technique for urchin barrens along the coast of Jeju Island that uses hyperspectral images and categorizes the urchin barrens into initial, intermediate, and advanced stages. The results showed that approximately 17.5% of the experimental areas were in the advanced stage. Based on this, various management and restoration methods tailored to different categories of urchin barren can be proposed.

• Journal of Environmental Impact Assessment
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• v.33 no.5
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• pp.187-203
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• 2024

PM_2.5, a type of fine particulate matter, poses serious health risks. Existing pollution management policies and research have generally focused on high-concentration areas. However, this approach has limitations as it does not adequately account for regional characteristics and varying levels of vulnerability, leading to an incomplete reflection of actual risks in specific areas. This study analyzed 229 administrative districts to develop a vulnerability index by comprehensively evaluating PM_2.5 exposure, sensitivity, and adaptive capacity. Using data from 2019, the index was calculated through normalization and entropy weighting methods, and spatial patterns of PM_2.5 vulnerability were examined through LISA and K-means clustering analysis. The findings reveal that the distribution of PM_2.5-vulnerable areas shows distinct patterns within urban settings, which were classified into four distinct types, each characterized by different urban features. This suggests a need for region-specific dust reduction policies. This study contributes to a better understanding of the spatial patterns of PM_2.5 vulnerability and aims to support the development of more effective policy approaches.

• Journal of Korea Water Resources Association
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• v.57 no.10
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• pp.687-697
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• 2024

Providing a uniform velocity distribution at the inlet of the experimental flume through removing eddies, air bubbles, swirling flow and excessive velocity fluctuations as quickly and efficiently as possible is very important for the accurate reproduction and measurement of both flow velocity and phenomenon in the test reach. In this study, the flow straightener (FS) using multiple parallel PC (ploycarbonate) tubes was developed to increase the accuracy of flow measurement by quickly eliminating excessive velocity fluctuations and air bubbles. It was confirmed through a series of hydraulic experiments that FS using PC tubes can reduce the turbulence intensity (TI) by nearly half under all experimental configurations. The FS of PC tubes with a diameter of 20 mm and a length of 0.3 m can reduce the TI by more than 60% and the value can be maintained at about 2.4% that is in common at the inlet cross-section of the experimental flume. When the tube length is 0.3 m, the magnitude of TI decreases linearly as the tube diameter decreases, and it is desirable to keep the tube diameter at 20 mm to provide a definite flow conditioning effect. Small air bubbles formed at high flow conditions are found to grow in size and quickly rise to the free surface at the rising velocity of about 0.24 m/s due to increased buoyancy as they pass through the tubes. The removal function of air bubbles was not sensitive to the diameter and length of the PC tubes.

• Tuberculosis and Respiratory Diseases
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• v.40 no.6
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• pp.631-637
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• 1993

Background: In normal adults, ventilation is uneven and greater in the base than the apex of the lung in tidal volume breathing. However infants have fragile chest wall and reduced elastic recoil, resulting in easy closure of peripheral airways especially in the dependent portion of the lung. So ventilation in infants is greater in the apex than the base of the lung. We assumed that in adults whose closing volume is increased, dependent portion could be easily collapsed during tidal breathing and ventilation could be greater in the uppear than than the lower portion of the lung. Methods: We measured spirometry and closing volume(CV) in normal controls and in patients with chronic lung disease. Also we measured fractional distribution of ventilation at supine, left lateral and right lateral decubitus with $^{133}Xe$ ventilation scan in normal controls, patients with normal closing volume and patients with increased closing volume. Results: The subjects consisted of 7 normal controls(mean $age{\pm}SD$, $62.9{\pm}6.1$ years). 6 patients with normal CV($62.8{\pm}8.2$ years) and 7 patients with increased CV($63.0{\pm}15.3$ years). 1) Normal controls have mean(${\pm}SD$) FVC $104{\pm}11%$ of predicted value, $FEV_1\;120{\pm}16%,\;FEV_1/FVC\;112{\pm}5%$ and CV $86.9{\pm}12.5%$. Patients with normal CV have FVC $62{\pm}11%,\;FEV_1\;54{\pm}17%,\;FEV_1/FVC\;84{\pm}23%$ and CV $92.6{\pm}15.5%$. Patients with increased CV, have FVC $53{\pm}9%,\;FEV_1\;38{\pm}13,\;FEV_1/FVC\;69{\pm}16%$ and CV $176.1{\pm}36.6%$, CV was significantly different between two patient groups(p<0.02) 2). In normal controls mean fractional ventilation to left lung was $48.1{\pm}5.3%$ at supine, $54.1{\pm}9.8%$ at dependent and $40.9{\pm}6.5%$ at left uppermost position. In patients with normal CV mean fractional ventilation to left lung was $44.6{\pm}2.1%$ at supine, $59.7{\pm}5.6%$ at left dependent and $31.7{\pm}8.3%$ at left uppermost position. In patients with increased CV mean fractional ventilation to left lung was $48.7{\pm}4.5%$ at supine, $41.7{\pm}6.6%$ at left dependent and $60.9{\pm}15.7%$ at left uppermost position. In normal controls and patients with normal CV, ventilation to left lung at left dependent position tends to be higher than that at supine position but without statisitical significance and it was significantly lower at left uppermost than at left lung dependent position. In patients with increased CV, ventilation to left at left dependent position tends to be higher than that at supine position but without significance and it was significantly higher at left uppermost than that at left dependent position. Conclusion: These data suggest that in patients with increased CV ventilation to one side of lung could be higher at uppermost than at dependent position on lateral decubitus during tidal breathing and this fact should be taken into account in positioning of patients with unilateral lung disease.

• Pediatric Infection and Vaccine
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• v.14 no.1
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• pp.47-54
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• 2007

Purpose : Viral respiratory tract infection is most common cause for admission to hospital in children. There are many cases with elevated transaminase level in patients with viral lower respiratory tract infection (LRTI). The aim of this study was to compare indexes of disease severity such as duration of assisted ventilation, length of hospital stay and Respiratory Distress Assessment Instrument (RDAI) score in children with viral LRTI with and without elevated transaminase levels and to determine the etiology related to elevated transaminase levels in this patients group. Methods : Virological analysis was done from respiratory specimens obtained from patients with LRTI admitted to Kangnam Sacred Heart Hospital from Jan. 2003 to Jun. 2005. Viral diagnosis was made by isolation of viruses employing HEp-2 cell culture from nasopharyngeal aspiration. Medical records of children were reviewed retrospectively. We compared age, sex, RDAI score, Respiratory Rate (RR) score and mean duration of hospital stay between patients with elevated transaminase levels (Patient Group) and patients with normal transaminase levels (Control Group). Results : Viruses were isolated from 181 children with LRTI. 16 cases were excluded according to criteria. 28 cases (17.0%) had elevated transaminase levels (Patient group) and 137 cases (83.0%) had normal transaminase levels (Control group). There were no significant difference in duration of fever, RR score, RDAI score, incidence of $O_2$ inhalation and duration of hospital stay between patient group and control group. We found 17 (60.7%) cases of RSV, 4 cases (14.3%) of parainfluenza, 4 cases (14.3%) of influenza B virus, 3 cases (10.7%) of adenovirus and 1 case (3.6%) of influenza A virus infection in patient group and 78 cases (56.9%) of RSV, 28 cases (20.4%) of parainfluenza virus, 13 cases (9.5%) of influenza A virus, 9 cases (6.6%) of influenza B virus, 6 cases (4.4%) of adenovirus and 3 cases (2.2%) of coxsackie virus infection in control group. Conclusion : There were 28 cases (17.0%) with elevated transaminase level among patients with virus isolated LRTI. There was no relation between elevated transaminase level and severity of disease. The viral etiologies in two groups were not significantly different. There was no significant difference of age distribution between two groups.

• Analytical Science and Technology
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• v.27 no.1
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• pp.1-10
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• 2014

The $PM_{10}$ and $PM_{2.5}$ samples were collected at Gosan Site of Jeju Island, and analyzed, in order to investigate the size distribution and pollution characteristics of their components. $NH{_4}{^+}$, nss-$SO{_4}^{2-}$, $K^+$, and $CH_3COO^-$ were mostly existed in fine particles. Meanwhile, $NO{_3}{^-}$ was distributed in both fine and coarse particles, and $Na^+$, $Cl^-$, $Mg^{2+}$, nss-$Ca^{2+}$ were rich in coarse particle mode. The concentrations of nss-$Ca^{2+}$ and $NO{_3}{^-}$ were increased 36.7 and 3.2 times in coarse particles, and 15.0 and 3.1 times in fine particles during the Asian Dust periods. Especially, the concentrations of crustal elemental species such as Al, Fe, Ca, K, Mg, Ti, Mn, Sr, Ba were highly increased for those periods. In the haze events, the concentrations of secondary air pollutants were increased 1.3~2.6 and 1.5~4.2 times in coarse and fine particles, respectively. Moreover, the remarkable increase of $NO{_3}{^-}$ concentration was also observed in fine particle mode. The factor analysis showed that the composition of coarse particles was influenced mainly by marine sources, followed by soil and anthropogenic sources. On the other hand, the fine particles were influenced by anthropogenic sources, followed by marine and soil sources.

• Journal of the Korean Electrochemical Society
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• v.23 no.2
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• pp.39-46
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• 2020

Composite electrodes for rechargeable batteries generally consist of active material, electric conductor, and polymeric binder. And their composition and distribution within the composite electrode determine the electrochemical activity in the electrochemical systems. However, it is not easy to quantify the physical properties of composite electrodes themselves using conventional experimental analysis tools. So, 3D structural modeling and simulation can be an efficient design tool by looking into the contact areas between particles and electric conductivity within the composite electrode. In this study, while maintaining the composition (LiCoO₂ : Super P Li^® : Polyvinylidene Fluoride (PVdF) = 93 : 3 : 4 by wt%) and loading level (13 mg cm^-2) of the composite electrode, the effects of LiCoO₂ size (10 ㎛ and 20 ㎛) and electrode density (2.8 g cm^-3, 3.0 g cm^-3, 3.2 g cm^-3, 3.5 g cm^-3, 4.0 g cm^-3) on the physical properties are investigated using a GeoDict software. With this tool, the composite electrode can be efficiently designed to optimize the contact area and electric conductivity.

• Economic and Environmental Geology
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• v.49 no.6
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• pp.417-432
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• 2016

It was firstly revealed in this research that the marine terrace of the Ijin-ri (Bukpyung-myeon, Haenam-gun) was formed during the last interglacial (Marine Isotope Stage 5e; MIS 5e). The marine terrace totally ranging from 4.8 m (asl) to 8.8 m (asl) is subdivided into 4 units; Unit I ranges 4.8-5.3 m, unit II ranges 5.3-6.9 m, unit III ranges 6.9-8.3 m, and unit IV ranges 8.3-8.8 m. Strong evidences that units II and III were formed during MIS5e were obtained based on OSL dating, the physical characterizations such as particle size distribution, magnetic susceptibility and water content, principal element and trace element analyses, and quantitative clay mineral analysis for samples at the 30 cm intervals. The rounded gravels on the marine terrace are regarded to be originated from the clastic materials transported directly from the surrounding mountains toward the marine and abraded in the coastal area, without any fluvial processes. During the warmest period (125k, unit II), the increase in rainfall, along with the rapid rise in sea level, was likely caused the high amount of clastic materials transported to the upper part of the beach. As a result of comparing clay mineral ratios of study site with those derived from sediments of either tidal flats, or the Yellow Sea, it is interpreted that the sediments of study site were influenced from the marine. The results will be used to investigate the hydrological activity and sedimentary environment during the high sea level in the past.

• The Journal of the Petrological Society of Korea
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• v.27 no.3
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• pp.153-171
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• 2018

This study focuses on the investigation of geologic distribution and stratigraphy in the eastern part of Yeongdeok-gun, based on Lidar imaging, detailed field survey, microscopic observations, SHRIMP and LA-MC-ICPMS U-Pb age dating, and a new geological map has been created. The stratigraphy of the study area is composed of the Paleoproterozoic metamorphic rocks consisting of banded gneisses of sedimentary origin and schists ($1841.5{\pm}9.6Ma$) of volcanic origin, Triassic Yeongdeok plutonic rocks ($249.1{\pm}2.3Ma$) and Pinkish granites ($242.4{\pm}2.4Ma$), Jurassic Changpo plutonic rocks ($193.2{\pm}1.9Ma{\sim}188.8{\pm}2.0Ma$) and Fine-grained granites ($192.9{\pm}1.7Ma$), Formations [Gyeongjeongdong Fm, Ullyeonsan Fm. (~108 Ma), Donghwachi Fm.] of the Early Cretaceous Gyeongsang Supergroup and acidic volcanic rocks and dykes erupted and intruded in the Late Cretaceous, Miocene intrusive rhyolitic tuffs ($23.1{\pm}0.2Ma{\sim}22.97{\pm}0.13Ma$) and sedimentary rocks of the Yeonghae basin, and the Quaternary sediments. The Triassic Pinkish granites, Jurassic Changpo plutonic rocks and Fine-grained granites are newly defined plutonic rocks in this study. Miocene intrusive rhyolitic tuffs bounded by the Yangsan Fault, which was first discovered in the north of Pohang city, are believed to play an important role in the understanding of the Miocene volcanic activity and the crustal deformation history on the Korean Peninsula. It is confirmed that The NNE-SSW-striking Yangsan Fault penetrating the central part of the study area and branch faults are predominant in the dextral movement and cutting all strata except the Quaternary sediments.