• Korean Journal of Remote Sensing
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• v.31 no.4
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• pp.337-346
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• 2015

Water body extraction based on backscatter information is an essential process to analyze floodaffected areas from Synthetic Aperture Radar (SAR) image. Water body in SAR image tends to have low backscatter values due to homogeneous surface of water, while non-water body has higher backscatter values than water body. Non-water body, however, may also have low backscatter values in high resolution SAR image such as Kompsat-5 image, depending on surface characteristic of the ground. The objective of this paper is to present a method to increase backscatter contrast between water body and non-water body and also to remove efficiently misclassified pixels beyond true water body area. We create an entropy image using a Gray Level Co-occurrence Matrix (GLCM) and classify the entropy image into water body and non-water body pixels by thresholding of the entropy image. In order to reduce the effect of threshold value, we also propose Water Body Texture Index (WBTI), which measures simultaneously the occurrence of repeated water body pixel pair and the uniformity of water body in the binary entropy image. The proposed method produced high overall accuracy of 99.00% and Kappa coefficient of 90.38% in water body extraction using Kompsat-5 image. The accuracy analysis indicates that the proposed WBTI method is less affected by the choice of threshold value and successfully maintains high overall accuracy and Kappa coefficient in wide threshold range.

• Korean Journal of Remote Sensing
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• v.31 no.4
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• pp.293-302
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• 2015

Water body extraction is significant for flood disaster monitoring using satellite imagery. Conventional methods have focused on finding an index, which highlights water body and suppresses non-water body such as vegetation or soil area. The Normalized Difference Water Index (NDWI) is typically used to extract water body from satellite images. The drawback of NDWI, however, is that some man-made objects in built-up areas have NDWI values similar to water body. The objective of this paper is to propose a new method that could extract correctly water body with built-up areas in before and after images of flood. We first create a two-element feature vector consisting of NDWI and a Near InfRared band (NIR) and then select a training site on water body area. After computing the mean vector and the covariance matrix of the training site, we classify each pixel into water body based on Mahalanobis distance. We also register before and after images of flood using outlier removal and triangulation-based local transformation. We finally create a change map by combining the before-flooding water body and after-flooding water body. The experimental results show that the overall accuracy and Kappa coefficient of the proposed method were 97.25% and 94.14%, respectively, while those of the NDWI method were 89.5% and 69.6%, respectively.

• Korean Journal of Remote Sensing
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• v.32 no.5
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• pp.471-482
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• 2016

This paper presents an extraction method for water body which uses block-based image partitioning and extension of water body boundaries to improve the performance of supervised classification for water body extraction. The Mahalanobis distance image is created by computing the spectral information of Normalized Difference Water Index (NDWI) and Near Infrared (NIR) band images over a training site within the water body in order to extract an initial water body area. To reduce the effect of noise contained in the Mahalanobis distance image, we apply mean curvature diffusion to the image, which controls diffusion coefficients based on connectivity strength between adjacent pixels and then extract the initial water body area. After partitioning the extracted water body image into the non-overlapping blocks of same size, we update the water body area using the information of water body belonging to water body boundaries. The update is performed repeatedly under the condition that the statistical distance between water body area belonging to water body boundaries and the training site is not greater than a threshold value. The accuracy assessment of the proposed algorithm was tested using KOMPSAT-2 images for the various block sizes between $11{\times}11$ and $19{\times}19$. The overall accuracy and Kappa coefficient of the algorithm varied from 99.47% to 99.53% and from 95.07% to 95.80%, respectively.

• Korean Journal of Pharmacognosy
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• v.45 no.1
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• pp.55-61
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• 2014

Microwaves are non-ionizing electromagnetic waves of frequency between 300MHz to 300GHz and positioned between the X-ray and infrared rays in the electromagnetic spectrum. In recent years, the use of microwave for extraction of ingredient from plant material has shown remarkable research interest and potential. Scutellaria radix has been used as a traditional medicine for a variety of diseases. It has been reported to exert beneficial health effects, such as anti-bacterial, antiviral, anti-inflammatory, and free-radical scavenging. Oxidative stress or the accumulation of reactive oxygen species (ROS) leads neuronal cellular death and dysfunction, and it contributes to neuronal degenerative disease such as Alzheimer's disease, Parkinson's disease and stroke. In this study, we aimed to compare the neuroprotective and antioxidant effect of Scutellaria radix extracted by different methods using hot-water extraction (SBE-DW) or microwave extraction (SBE-DW-MW). As a result, we first examined HPLC analysis of hot-water and microwave extracts of Scutellaria radix. The hot-water and microwave extracts of Scutellaria radix showed the discernible difference patterns of HPLC analysis. Microwave-water extracts of Scutellaria radix increased DPPH radical scavenging activity more than hot-water extraction. Microwave-water extracts of Scutellaria radix also showed neuroprotective effects and ROS inhibition against glutamate-induced oxidative stress in mouse hippocampal HT22 cells, but hot-water extraction not showed. In addition, the phosphorylation of MAPKs induced by glutamate insult was prevented by microwave-water extracts of Scutellaria radix. Thus, these results suggested that microwave extraction can be utilized for improving the extraction efficiency and biological activity of Scutellaria radix.

• Journal of Mushroom
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• v.18 no.3
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• pp.244-253
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• 2020

The aim of this study was to investigate the biological activity of extracts obtained from the mycelium, sclerotium, and fruiting body of Wolfiporia cocos using different extraction solvents (hot water, 70% ethanol, and 70% methanol). Among the three developmental stages, the mycelium extracts showed the highest DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, ferric reducing antioxidant power (FRAP), nitrite scavenging activity, and total polyphenolic content. Among the extraction solvents in the context of the W. cocos mycelium, the DPPH radical scavenging activity, FRAP, and total polyphenol content in the hot-water extracts were significantly higher than those in the other extracts. In the case of the sclerotium, the reducing power, nitrite scavenging activity, and total polyphenol content were significantly higher in 70% ethanolic extracts. The fruiting body showed the highest DPPH radical scavenging activity, reducing power, nitrite scavenging activity, and total polyphenol content in the context of hot-water extraction. Moreover, the β-glucan content was significantly higher in the sclerotium versus the mycelium or fruiting body. The total amino acid and total essential amino acid contents were remarkably higher in the mycelium and fruiting body than in the sclerotium; of note, and arginine (Arg) and phenylalanine (Phe) were highly detected among the amino acid components.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.419-424
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• 2009

Water and 70% ethanol extracts obtained from a sea cucumber (Stichopus japonicus) body wall by heat reflux or pressurized solvent extraction showed 2,2-diphenyl-1-picrylhydrazyl ($DPPH^{\cdot}$) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation ($ABTS^{{\cdot}+}$) scavenging activities comparable to those of fruits and vegetables. The highest activities were observed for the water extract from heat reflux extraction. Crude saponins exhibited higher radical scavenging activities than the soluble matters in the extracts. However, they were responsible for only about 3 to 15% of the scavenging activities of the extracts. Total phenolic contents showed a significant correlation with $DPPH^{\cdot}$ scavenging activities, suggesting a significant contribution of phenolic constituents to the antioxidant properties of the extracts. However, total flavonoid contents showed little correlation with the radical scavenging activities. The results suggest that the water or 70% ethanol extract obtained from sea cucumber body wall by simple heat reflux extraction could provide considerable antioxidant benefits.

• Journal of Ocean Engineering and Technology
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• v.35 no.4
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• pp.296-304
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• 2021

Research on the development of marine renewable energy is actively in progress. Various studies are being conducted on the development of wave energy converters. In this study, a numerical analysis of wave-energy extraction performance was performed according to the body shape and scale of the sloped oscillating water column (OWC) wave energy converter (WEC), which can be connected with the breakwater. The sloped OWC WEC was modeled in the time domain using a two-dimensional fully nonlinear numerical wave tank. The nonlinear free surface condition in the chamber was derived to represent the pneumatic pressure owing to the wave column motion and viscous energy loss at the chamber entrance. The free surface elevations in the sloped chamber were calculated at various incident wave periods. For verification, the results were compared with the 1:20 scaled model test. The maximum wave energy extraction was estimated with a pneumatic damping coefficient. To calculate the energy extraction of the actual size WEC, OWC models approximately 20 times larger than the scale model were calculated, and the viscous damping coefficient according to each size was predicted and applied. It was verified that the energy, owing to the airflow in the chamber, increased as the incident wave period increased, and the maximum efficiency of energy extraction was approximately 40% of the incident wave energy. Under the given incident wave conditions, the maximum extractable wave power at a chamber length of 5 m and a skirt draft of 2 m was approximately 4.59 kW/m.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.1
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• pp.109-115
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• 2014

This paper investigated the optimal conditions for coffee extraction and dilution by comparing differences in soluble compounds and sensory characteristics of coffee subjected to cold-water extraction according to water quantity and dilution ratio. For sample preparation, we extracted coffee for 3 to 10 hours by adding 400 mL, 600 mL, 1,000 mL and 1,800 mL of cold water ($20^{\circ}C$) to 100 g of ground coffee, resulting in 200 mL, 400 mL, 800 mL and 1,600 mL portions of extracted coffee, respectively. Following this, the 200 mL, 400 mL and 800 mL portions of extracted coffee were further diluted with 1,400 mL, 1,200 mL and 800 mL of cold water, resulting in ratios of coffee to cold water of 1:7, 1:3 and 1:1, respectively. The 1,600 mL of portion of extracted coffee was not diluted and used as a sample. Undiluted coffee showed the highest values for pH, acidity, reducing sugar, total soluble solids and total phenolic compounds among all sample coffees, whereas the highly diluted coffee with a high ratio of 1:7 showed the lowest values. In a descriptive test, odor, sourness, bitterness and body intensity were also the highest in undiluted coffee due to the overly extracted coffee compounds. Undiluted coffee showed the lowest preference in terms of aroma, aftertaste and balanced coffee taste. On the other hand, diluted coffee at a ratio of 1:7 showed the lowest values for odor, sourness, bitterness and body intensity. Diluted coffee at a ratio of 1:3 showed the highest values for sweetness and acidity and was the most preferred in terms of aroma, aftertaste and balance. As a result, our study concluded that the optimal conditions for extraction and dilution of coffee with cold water are a ratio of ground coffee to cold water of 1:6 (w/v), followed by further dilution of the coffee by cold water at a ratio of 1:3.

• International Journal of Computer Science & Network Security
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• v.23 no.1
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• pp.1-10
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• 2023

Open surface water body extraction is gaining popularity in recent years due to its versatile applications. Multiple techniques are used for water detection based on applications. Different applications of Radar as LADAR, Ground-penetrating, synthetic aperture, and sounding radars are used to detect water. Shortwave infrared, thermal, optical, and multi-spectral sensors are widely used to detect water bodies. A stereo camera is another way to detect water and different methods are applied to the images of stereo cameras such as deep learning, machine learning, polarization, color variations, and descriptors are used to segment water and no water areas. The Satellite is also used at a high level to get water imagery and the captured imagery is processed using various methods such as features extraction, thresholding, entropy-based, and machine learning to find water on the surface. In this paper, we have summarized all the available methods to detect water areas. The main focus of this survey is on water detection especially in small patches or in small areas. The second aim of this survey is to detect water hazards for unmanned vehicles and off-sure navigation.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.83-84
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• 2016

For the slip resistance test of shower room floor, the "O-Y Pull Slip Meter method (O-Y·PSM)" regulated under KS M 3510. This test method uses cooking oil as a substitute of soapy water, and thus it does not reflect the real condition. In this study, on 10 types of floor material samples, the Coefficient of Slip Resistance Bath (CSR·B) on bare foot between 10 types of body wash solution and 6 types of SDS solution was compared. The body wash solution is a mixture of soap and water in 1:20 ratio. As a result, SDS 0.1% solution was the most suitable for a substitute of soapy water in shower.